[www-releases] r230777 - Upload 3.6.0

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Fri Feb 27 10:44:12 PST 2015


Added: www-releases/trunk/3.6.0/docs/LangRef.html
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/3.6.0/docs/LangRef.html?rev=230777&view=auto
==============================================================================
--- www-releases/trunk/3.6.0/docs/LangRef.html (added)
+++ www-releases/trunk/3.6.0/docs/LangRef.html Fri Feb 27 12:44:09 2015
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+            
+  <div class="section" id="llvm-language-reference-manual">
+<h1>LLVM Language Reference Manual<a class="headerlink" href="#llvm-language-reference-manual" title="Permalink to this headline">¶</a></h1>
+<div class="contents local topic" id="contents">
+<ul class="simple">
+<li><a class="reference internal" href="#abstract" id="id579">Abstract</a></li>
+<li><a class="reference internal" href="#introduction" id="id580">Introduction</a><ul>
+<li><a class="reference internal" href="#well-formedness" id="id581">Well-Formedness</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#identifiers" id="id582">Identifiers</a></li>
+<li><a class="reference internal" href="#high-level-structure" id="id583">High Level Structure</a><ul>
+<li><a class="reference internal" href="#module-structure" id="id584">Module Structure</a></li>
+<li><a class="reference internal" href="#linkage-types" id="id585">Linkage Types</a></li>
+<li><a class="reference internal" href="#calling-conventions" id="id586">Calling Conventions</a></li>
+<li><a class="reference internal" href="#visibility-styles" id="id587">Visibility Styles</a></li>
+<li><a class="reference internal" href="#dll-storage-classes" id="id588">DLL Storage Classes</a></li>
+<li><a class="reference internal" href="#thread-local-storage-models" id="id589">Thread Local Storage Models</a></li>
+<li><a class="reference internal" href="#structure-types" id="id590">Structure Types</a></li>
+<li><a class="reference internal" href="#global-variables" id="id591">Global Variables</a></li>
+<li><a class="reference internal" href="#functions" id="id592">Functions</a></li>
+<li><a class="reference internal" href="#aliases" id="id593">Aliases</a></li>
+<li><a class="reference internal" href="#comdats" id="id594">Comdats</a></li>
+<li><a class="reference internal" href="#named-metadata" id="id595">Named Metadata</a></li>
+<li><a class="reference internal" href="#parameter-attributes" id="id596">Parameter Attributes</a></li>
+<li><a class="reference internal" href="#garbage-collector-names" id="id597">Garbage Collector Names</a></li>
+<li><a class="reference internal" href="#prefix-data" id="id598">Prefix Data</a></li>
+<li><a class="reference internal" href="#prologue-data" id="id599">Prologue Data</a></li>
+<li><a class="reference internal" href="#attribute-groups" id="id600">Attribute Groups</a></li>
+<li><a class="reference internal" href="#function-attributes" id="id601">Function Attributes</a></li>
+<li><a class="reference internal" href="#module-level-inline-assembly" id="id602">Module-Level Inline Assembly</a></li>
+<li><a class="reference internal" href="#data-layout" id="id603">Data Layout</a></li>
+<li><a class="reference internal" href="#target-triple" id="id604">Target Triple</a></li>
+<li><a class="reference internal" href="#pointer-aliasing-rules" id="id605">Pointer Aliasing Rules</a></li>
+<li><a class="reference internal" href="#volatile-memory-accesses" id="id606">Volatile Memory Accesses</a></li>
+<li><a class="reference internal" href="#memory-model-for-concurrent-operations" id="id607">Memory Model for Concurrent Operations</a></li>
+<li><a class="reference internal" href="#atomic-memory-ordering-constraints" id="id608">Atomic Memory Ordering Constraints</a></li>
+<li><a class="reference internal" href="#fast-math-flags" id="id609">Fast-Math Flags</a></li>
+<li><a class="reference internal" href="#use-list-order-directives" id="id610">Use-list Order Directives</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#type-system" id="id611">Type System</a><ul>
+<li><a class="reference internal" href="#void-type" id="id612">Void Type</a></li>
+<li><a class="reference internal" href="#function-type" id="id613">Function Type</a></li>
+<li><a class="reference internal" href="#first-class-types" id="id614">First Class Types</a><ul>
+<li><a class="reference internal" href="#single-value-types" id="id615">Single Value Types</a><ul>
+<li><a class="reference internal" href="#integer-type" id="id616">Integer Type</a></li>
+<li><a class="reference internal" href="#floating-point-types" id="id617">Floating Point Types</a></li>
+<li><a class="reference internal" href="#x86-mmx-type" id="id618">X86_mmx Type</a></li>
+<li><a class="reference internal" href="#pointer-type" id="id619">Pointer Type</a></li>
+<li><a class="reference internal" href="#vector-type" id="id620">Vector Type</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#label-type" id="id621">Label Type</a></li>
+<li><a class="reference internal" href="#metadata-type" id="id622">Metadata Type</a></li>
+<li><a class="reference internal" href="#aggregate-types" id="id623">Aggregate Types</a><ul>
+<li><a class="reference internal" href="#array-type" id="id624">Array Type</a></li>
+<li><a class="reference internal" href="#structure-type" id="id625">Structure Type</a></li>
+<li><a class="reference internal" href="#opaque-structure-types" id="id626">Opaque Structure Types</a></li>
+</ul>
+</li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#constants" id="id627">Constants</a><ul>
+<li><a class="reference internal" href="#simple-constants" id="id628">Simple Constants</a></li>
+<li><a class="reference internal" href="#complex-constants" id="id629">Complex Constants</a></li>
+<li><a class="reference internal" href="#global-variable-and-function-addresses" id="id630">Global Variable and Function Addresses</a></li>
+<li><a class="reference internal" href="#undefined-values" id="id631">Undefined Values</a></li>
+<li><a class="reference internal" href="#poison-values" id="id632">Poison Values</a></li>
+<li><a class="reference internal" href="#addresses-of-basic-blocks" id="id633">Addresses of Basic Blocks</a></li>
+<li><a class="reference internal" href="#constant-expressions" id="id634">Constant Expressions</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#other-values" id="id635">Other Values</a><ul>
+<li><a class="reference internal" href="#inline-assembler-expressions" id="id636">Inline Assembler Expressions</a><ul>
+<li><a class="reference internal" href="#inline-asm-metadata" id="id637">Inline Asm Metadata</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#metadata" id="id638">Metadata</a><ul>
+<li><a class="reference internal" href="#metadata-nodes-and-metadata-strings" id="id639">Metadata Nodes and Metadata Strings</a><ul>
+<li><a class="reference internal" href="#specialized-metadata-nodes" id="id640">Specialized Metadata Nodes</a><ul>
+<li><a class="reference internal" href="#mdlocation" id="id641">MDLocation</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#tbaa-metadata" id="id642">‘<tt class="docutils literal"><span class="pre">tbaa</span></tt>‘ Metadata</a></li>
+<li><a class="reference internal" href="#tbaa-struct-metadata" id="id643">‘<tt class="docutils literal"><span class="pre">tbaa.struct</span></tt>‘ Metadata</a></li>
+<li><a class="reference internal" href="#noalias-and-alias-scope-metadata" id="id644">‘<tt class="docutils literal"><span class="pre">noalias</span></tt>‘ and ‘<tt class="docutils literal"><span class="pre">alias.scope</span></tt>‘ Metadata</a></li>
+<li><a class="reference internal" href="#fpmath-metadata" id="id645">‘<tt class="docutils literal"><span class="pre">fpmath</span></tt>‘ Metadata</a></li>
+<li><a class="reference internal" href="#range-metadata" id="id646">‘<tt class="docutils literal"><span class="pre">range</span></tt>‘ Metadata</a></li>
+<li><a class="reference internal" href="#llvm-loop" id="id647">‘<tt class="docutils literal"><span class="pre">llvm.loop</span></tt>‘</a></li>
+<li><a class="reference internal" href="#llvm-loop-vectorize-and-llvm-loop-interleave" id="id648">‘<tt class="docutils literal"><span class="pre">llvm.loop.vectorize</span></tt>‘ and ‘<tt class="docutils literal"><span class="pre">llvm.loop.interleave</span></tt>‘</a></li>
+<li><a class="reference internal" href="#llvm-loop-interleave-count-metadata" id="id649">‘<tt class="docutils literal"><span class="pre">llvm.loop.interleave.count</span></tt>‘ Metadata</a></li>
+<li><a class="reference internal" href="#llvm-loop-vectorize-enable-metadata" id="id650">‘<tt class="docutils literal"><span class="pre">llvm.loop.vectorize.enable</span></tt>‘ Metadata</a></li>
+<li><a class="reference internal" href="#llvm-loop-vectorize-width-metadata" id="id651">‘<tt class="docutils literal"><span class="pre">llvm.loop.vectorize.width</span></tt>‘ Metadata</a></li>
+<li><a class="reference internal" href="#llvm-loop-unroll" id="id652">‘<tt class="docutils literal"><span class="pre">llvm.loop.unroll</span></tt>‘</a></li>
+<li><a class="reference internal" href="#llvm-loop-unroll-count-metadata" id="id653">‘<tt class="docutils literal"><span class="pre">llvm.loop.unroll.count</span></tt>‘ Metadata</a></li>
+<li><a class="reference internal" href="#llvm-loop-unroll-disable-metadata" id="id654">‘<tt class="docutils literal"><span class="pre">llvm.loop.unroll.disable</span></tt>‘ Metadata</a></li>
+<li><a class="reference internal" href="#llvm-loop-unroll-full-metadata" id="id655">‘<tt class="docutils literal"><span class="pre">llvm.loop.unroll.full</span></tt>‘ Metadata</a></li>
+<li><a class="reference internal" href="#llvm-mem" id="id656">‘<tt class="docutils literal"><span class="pre">llvm.mem</span></tt>‘</a></li>
+<li><a class="reference internal" href="#llvm-mem-parallel-loop-access-metadata" id="id657">‘<tt class="docutils literal"><span class="pre">llvm.mem.parallel_loop_access</span></tt>‘ Metadata</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#module-flags-metadata" id="id658">Module Flags Metadata</a><ul>
+<li><a class="reference internal" href="#objective-c-garbage-collection-module-flags-metadata" id="id659">Objective-C Garbage Collection Module Flags Metadata</a></li>
+<li><a class="reference internal" href="#automatic-linker-flags-module-flags-metadata" id="id660">Automatic Linker Flags Module Flags Metadata</a></li>
+<li><a class="reference internal" href="#c-type-width-module-flags-metadata" id="id661">C type width Module Flags Metadata</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#intrinsic-global-variables" id="id662">Intrinsic Global Variables</a><ul>
+<li><a class="reference internal" href="#the-llvm-used-global-variable" id="id663">The ‘<tt class="docutils literal"><span class="pre">llvm.used</span></tt>‘ Global Variable</a></li>
+<li><a class="reference internal" href="#the-llvm-compiler-used-global-variable" id="id664">The ‘<tt class="docutils literal"><span class="pre">llvm.compiler.used</span></tt>‘ Global Variable</a></li>
+<li><a class="reference internal" href="#the-llvm-global-ctors-global-variable" id="id665">The ‘<tt class="docutils literal"><span class="pre">llvm.global_ctors</span></tt>‘ Global Variable</a></li>
+<li><a class="reference internal" href="#the-llvm-global-dtors-global-variable" id="id666">The ‘<tt class="docutils literal"><span class="pre">llvm.global_dtors</span></tt>‘ Global Variable</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#instruction-reference" id="id667">Instruction Reference</a><ul>
+<li><a class="reference internal" href="#terminator-instructions" id="id668">Terminator Instructions</a><ul>
+<li><a class="reference internal" href="#ret-instruction" id="id669">‘<tt class="docutils literal"><span class="pre">ret</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#syntax" id="id670">Syntax:</a></li>
+<li><a class="reference internal" href="#overview" id="id671">Overview:</a></li>
+<li><a class="reference internal" href="#arguments" id="id672">Arguments:</a></li>
+<li><a class="reference internal" href="#semantics" id="id673">Semantics:</a></li>
+<li><a class="reference internal" href="#example" id="id674">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#br-instruction" id="id675">‘<tt class="docutils literal"><span class="pre">br</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id5" id="id676">Syntax:</a></li>
+<li><a class="reference internal" href="#id6" id="id677">Overview:</a></li>
+<li><a class="reference internal" href="#id7" id="id678">Arguments:</a></li>
+<li><a class="reference internal" href="#id8" id="id679">Semantics:</a></li>
+<li><a class="reference internal" href="#id9" id="id680">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#switch-instruction" id="id681">‘<tt class="docutils literal"><span class="pre">switch</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id10" id="id682">Syntax:</a></li>
+<li><a class="reference internal" href="#id11" id="id683">Overview:</a></li>
+<li><a class="reference internal" href="#id12" id="id684">Arguments:</a></li>
+<li><a class="reference internal" href="#id13" id="id685">Semantics:</a></li>
+<li><a class="reference internal" href="#implementation" id="id686">Implementation:</a></li>
+<li><a class="reference internal" href="#id14" id="id687">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#indirectbr-instruction" id="id688">‘<tt class="docutils literal"><span class="pre">indirectbr</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id15" id="id689">Syntax:</a></li>
+<li><a class="reference internal" href="#id16" id="id690">Overview:</a></li>
+<li><a class="reference internal" href="#id17" id="id691">Arguments:</a></li>
+<li><a class="reference internal" href="#id18" id="id692">Semantics:</a></li>
+<li><a class="reference internal" href="#id19" id="id693">Implementation:</a></li>
+<li><a class="reference internal" href="#id20" id="id694">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#invoke-instruction" id="id695">‘<tt class="docutils literal"><span class="pre">invoke</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id21" id="id696">Syntax:</a></li>
+<li><a class="reference internal" href="#id22" id="id697">Overview:</a></li>
+<li><a class="reference internal" href="#id23" id="id698">Arguments:</a></li>
+<li><a class="reference internal" href="#id24" id="id699">Semantics:</a></li>
+<li><a class="reference internal" href="#id25" id="id700">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#resume-instruction" id="id701">‘<tt class="docutils literal"><span class="pre">resume</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id26" id="id702">Syntax:</a></li>
+<li><a class="reference internal" href="#id27" id="id703">Overview:</a></li>
+<li><a class="reference internal" href="#id28" id="id704">Arguments:</a></li>
+<li><a class="reference internal" href="#id29" id="id705">Semantics:</a></li>
+<li><a class="reference internal" href="#id30" id="id706">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#unreachable-instruction" id="id707">‘<tt class="docutils literal"><span class="pre">unreachable</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id31" id="id708">Syntax:</a></li>
+<li><a class="reference internal" href="#id32" id="id709">Overview:</a></li>
+<li><a class="reference internal" href="#id33" id="id710">Semantics:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#binary-operations" id="id711">Binary Operations</a><ul>
+<li><a class="reference internal" href="#add-instruction" id="id712">‘<tt class="docutils literal"><span class="pre">add</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id34" id="id713">Syntax:</a></li>
+<li><a class="reference internal" href="#id35" id="id714">Overview:</a></li>
+<li><a class="reference internal" href="#id36" id="id715">Arguments:</a></li>
+<li><a class="reference internal" href="#id37" id="id716">Semantics:</a></li>
+<li><a class="reference internal" href="#id38" id="id717">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#fadd-instruction" id="id718">‘<tt class="docutils literal"><span class="pre">fadd</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id39" id="id719">Syntax:</a></li>
+<li><a class="reference internal" href="#id40" id="id720">Overview:</a></li>
+<li><a class="reference internal" href="#id41" id="id721">Arguments:</a></li>
+<li><a class="reference internal" href="#id42" id="id722">Semantics:</a></li>
+<li><a class="reference internal" href="#id43" id="id723">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#sub-instruction" id="id724">‘<tt class="docutils literal"><span class="pre">sub</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id44" id="id725">Syntax:</a></li>
+<li><a class="reference internal" href="#id45" id="id726">Overview:</a></li>
+<li><a class="reference internal" href="#id46" id="id727">Arguments:</a></li>
+<li><a class="reference internal" href="#id47" id="id728">Semantics:</a></li>
+<li><a class="reference internal" href="#id48" id="id729">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#fsub-instruction" id="id730">‘<tt class="docutils literal"><span class="pre">fsub</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id49" id="id731">Syntax:</a></li>
+<li><a class="reference internal" href="#id50" id="id732">Overview:</a></li>
+<li><a class="reference internal" href="#id51" id="id733">Arguments:</a></li>
+<li><a class="reference internal" href="#id52" id="id734">Semantics:</a></li>
+<li><a class="reference internal" href="#id53" id="id735">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#mul-instruction" id="id736">‘<tt class="docutils literal"><span class="pre">mul</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id54" id="id737">Syntax:</a></li>
+<li><a class="reference internal" href="#id55" id="id738">Overview:</a></li>
+<li><a class="reference internal" href="#id56" id="id739">Arguments:</a></li>
+<li><a class="reference internal" href="#id57" id="id740">Semantics:</a></li>
+<li><a class="reference internal" href="#id58" id="id741">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#fmul-instruction" id="id742">‘<tt class="docutils literal"><span class="pre">fmul</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id59" id="id743">Syntax:</a></li>
+<li><a class="reference internal" href="#id60" id="id744">Overview:</a></li>
+<li><a class="reference internal" href="#id61" id="id745">Arguments:</a></li>
+<li><a class="reference internal" href="#id62" id="id746">Semantics:</a></li>
+<li><a class="reference internal" href="#id63" id="id747">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#udiv-instruction" id="id748">‘<tt class="docutils literal"><span class="pre">udiv</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id64" id="id749">Syntax:</a></li>
+<li><a class="reference internal" href="#id65" id="id750">Overview:</a></li>
+<li><a class="reference internal" href="#id66" id="id751">Arguments:</a></li>
+<li><a class="reference internal" href="#id67" id="id752">Semantics:</a></li>
+<li><a class="reference internal" href="#id68" id="id753">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#sdiv-instruction" id="id754">‘<tt class="docutils literal"><span class="pre">sdiv</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id69" id="id755">Syntax:</a></li>
+<li><a class="reference internal" href="#id70" id="id756">Overview:</a></li>
+<li><a class="reference internal" href="#id71" id="id757">Arguments:</a></li>
+<li><a class="reference internal" href="#id72" id="id758">Semantics:</a></li>
+<li><a class="reference internal" href="#id73" id="id759">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#fdiv-instruction" id="id760">‘<tt class="docutils literal"><span class="pre">fdiv</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id74" id="id761">Syntax:</a></li>
+<li><a class="reference internal" href="#id75" id="id762">Overview:</a></li>
+<li><a class="reference internal" href="#id76" id="id763">Arguments:</a></li>
+<li><a class="reference internal" href="#id77" id="id764">Semantics:</a></li>
+<li><a class="reference internal" href="#id78" id="id765">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#urem-instruction" id="id766">‘<tt class="docutils literal"><span class="pre">urem</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id79" id="id767">Syntax:</a></li>
+<li><a class="reference internal" href="#id80" id="id768">Overview:</a></li>
+<li><a class="reference internal" href="#id81" id="id769">Arguments:</a></li>
+<li><a class="reference internal" href="#id82" id="id770">Semantics:</a></li>
+<li><a class="reference internal" href="#id83" id="id771">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#srem-instruction" id="id772">‘<tt class="docutils literal"><span class="pre">srem</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id84" id="id773">Syntax:</a></li>
+<li><a class="reference internal" href="#id85" id="id774">Overview:</a></li>
+<li><a class="reference internal" href="#id86" id="id775">Arguments:</a></li>
+<li><a class="reference internal" href="#id87" id="id776">Semantics:</a></li>
+<li><a class="reference internal" href="#id88" id="id777">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#frem-instruction" id="id778">‘<tt class="docutils literal"><span class="pre">frem</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id89" id="id779">Syntax:</a></li>
+<li><a class="reference internal" href="#id90" id="id780">Overview:</a></li>
+<li><a class="reference internal" href="#id91" id="id781">Arguments:</a></li>
+<li><a class="reference internal" href="#id92" id="id782">Semantics:</a></li>
+<li><a class="reference internal" href="#id93" id="id783">Example:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#bitwise-binary-operations" id="id784">Bitwise Binary Operations</a><ul>
+<li><a class="reference internal" href="#shl-instruction" id="id785">‘<tt class="docutils literal"><span class="pre">shl</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id94" id="id786">Syntax:</a></li>
+<li><a class="reference internal" href="#id95" id="id787">Overview:</a></li>
+<li><a class="reference internal" href="#id96" id="id788">Arguments:</a></li>
+<li><a class="reference internal" href="#id97" id="id789">Semantics:</a></li>
+<li><a class="reference internal" href="#id98" id="id790">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#lshr-instruction" id="id791">‘<tt class="docutils literal"><span class="pre">lshr</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id99" id="id792">Syntax:</a></li>
+<li><a class="reference internal" href="#id100" id="id793">Overview:</a></li>
+<li><a class="reference internal" href="#id101" id="id794">Arguments:</a></li>
+<li><a class="reference internal" href="#id102" id="id795">Semantics:</a></li>
+<li><a class="reference internal" href="#id103" id="id796">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#ashr-instruction" id="id797">‘<tt class="docutils literal"><span class="pre">ashr</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id104" id="id798">Syntax:</a></li>
+<li><a class="reference internal" href="#id105" id="id799">Overview:</a></li>
+<li><a class="reference internal" href="#id106" id="id800">Arguments:</a></li>
+<li><a class="reference internal" href="#id107" id="id801">Semantics:</a></li>
+<li><a class="reference internal" href="#id108" id="id802">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#and-instruction" id="id803">‘<tt class="docutils literal"><span class="pre">and</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id109" id="id804">Syntax:</a></li>
+<li><a class="reference internal" href="#id110" id="id805">Overview:</a></li>
+<li><a class="reference internal" href="#id111" id="id806">Arguments:</a></li>
+<li><a class="reference internal" href="#id112" id="id807">Semantics:</a></li>
+<li><a class="reference internal" href="#id113" id="id808">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#or-instruction" id="id809">‘<tt class="docutils literal"><span class="pre">or</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id114" id="id810">Syntax:</a></li>
+<li><a class="reference internal" href="#id115" id="id811">Overview:</a></li>
+<li><a class="reference internal" href="#id116" id="id812">Arguments:</a></li>
+<li><a class="reference internal" href="#id117" id="id813">Semantics:</a></li>
+<li><a class="reference internal" href="#id118" id="id814">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#xor-instruction" id="id815">‘<tt class="docutils literal"><span class="pre">xor</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id119" id="id816">Syntax:</a></li>
+<li><a class="reference internal" href="#id120" id="id817">Overview:</a></li>
+<li><a class="reference internal" href="#id121" id="id818">Arguments:</a></li>
+<li><a class="reference internal" href="#id122" id="id819">Semantics:</a></li>
+<li><a class="reference internal" href="#id123" id="id820">Example:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#vector-operations" id="id821">Vector Operations</a><ul>
+<li><a class="reference internal" href="#extractelement-instruction" id="id822">‘<tt class="docutils literal"><span class="pre">extractelement</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id124" id="id823">Syntax:</a></li>
+<li><a class="reference internal" href="#id125" id="id824">Overview:</a></li>
+<li><a class="reference internal" href="#id126" id="id825">Arguments:</a></li>
+<li><a class="reference internal" href="#id127" id="id826">Semantics:</a></li>
+<li><a class="reference internal" href="#id128" id="id827">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#insertelement-instruction" id="id828">‘<tt class="docutils literal"><span class="pre">insertelement</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id129" id="id829">Syntax:</a></li>
+<li><a class="reference internal" href="#id130" id="id830">Overview:</a></li>
+<li><a class="reference internal" href="#id131" id="id831">Arguments:</a></li>
+<li><a class="reference internal" href="#id132" id="id832">Semantics:</a></li>
+<li><a class="reference internal" href="#id133" id="id833">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#shufflevector-instruction" id="id834">‘<tt class="docutils literal"><span class="pre">shufflevector</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id134" id="id835">Syntax:</a></li>
+<li><a class="reference internal" href="#id135" id="id836">Overview:</a></li>
+<li><a class="reference internal" href="#id136" id="id837">Arguments:</a></li>
+<li><a class="reference internal" href="#id137" id="id838">Semantics:</a></li>
+<li><a class="reference internal" href="#id138" id="id839">Example:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#aggregate-operations" id="id840">Aggregate Operations</a><ul>
+<li><a class="reference internal" href="#extractvalue-instruction" id="id841">‘<tt class="docutils literal"><span class="pre">extractvalue</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id139" id="id842">Syntax:</a></li>
+<li><a class="reference internal" href="#id140" id="id843">Overview:</a></li>
+<li><a class="reference internal" href="#id141" id="id844">Arguments:</a></li>
+<li><a class="reference internal" href="#id142" id="id845">Semantics:</a></li>
+<li><a class="reference internal" href="#id143" id="id846">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#insertvalue-instruction" id="id847">‘<tt class="docutils literal"><span class="pre">insertvalue</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id144" id="id848">Syntax:</a></li>
+<li><a class="reference internal" href="#id145" id="id849">Overview:</a></li>
+<li><a class="reference internal" href="#id146" id="id850">Arguments:</a></li>
+<li><a class="reference internal" href="#id147" id="id851">Semantics:</a></li>
+<li><a class="reference internal" href="#id148" id="id852">Example:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#memory-access-and-addressing-operations" id="id853">Memory Access and Addressing Operations</a><ul>
+<li><a class="reference internal" href="#alloca-instruction" id="id854">‘<tt class="docutils literal"><span class="pre">alloca</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id149" id="id855">Syntax:</a></li>
+<li><a class="reference internal" href="#id150" id="id856">Overview:</a></li>
+<li><a class="reference internal" href="#id151" id="id857">Arguments:</a></li>
+<li><a class="reference internal" href="#id152" id="id858">Semantics:</a></li>
+<li><a class="reference internal" href="#id153" id="id859">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#load-instruction" id="id860">‘<tt class="docutils literal"><span class="pre">load</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id154" id="id861">Syntax:</a></li>
+<li><a class="reference internal" href="#id155" id="id862">Overview:</a></li>
+<li><a class="reference internal" href="#id156" id="id863">Arguments:</a></li>
+<li><a class="reference internal" href="#id157" id="id864">Semantics:</a></li>
+<li><a class="reference internal" href="#id158" id="id865">Examples:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#store-instruction" id="id866">‘<tt class="docutils literal"><span class="pre">store</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id159" id="id867">Syntax:</a></li>
+<li><a class="reference internal" href="#id160" id="id868">Overview:</a></li>
+<li><a class="reference internal" href="#id161" id="id869">Arguments:</a></li>
+<li><a class="reference internal" href="#id162" id="id870">Semantics:</a></li>
+<li><a class="reference internal" href="#id163" id="id871">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#fence-instruction" id="id872">‘<tt class="docutils literal"><span class="pre">fence</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id164" id="id873">Syntax:</a></li>
+<li><a class="reference internal" href="#id165" id="id874">Overview:</a></li>
+<li><a class="reference internal" href="#id166" id="id875">Arguments:</a></li>
+<li><a class="reference internal" href="#id167" id="id876">Semantics:</a></li>
+<li><a class="reference internal" href="#id168" id="id877">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#cmpxchg-instruction" id="id878">‘<tt class="docutils literal"><span class="pre">cmpxchg</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id169" id="id879">Syntax:</a></li>
+<li><a class="reference internal" href="#id170" id="id880">Overview:</a></li>
+<li><a class="reference internal" href="#id171" id="id881">Arguments:</a></li>
+<li><a class="reference internal" href="#id172" id="id882">Semantics:</a></li>
+<li><a class="reference internal" href="#id173" id="id883">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#atomicrmw-instruction" id="id884">‘<tt class="docutils literal"><span class="pre">atomicrmw</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id174" id="id885">Syntax:</a></li>
+<li><a class="reference internal" href="#id175" id="id886">Overview:</a></li>
+<li><a class="reference internal" href="#id176" id="id887">Arguments:</a></li>
+<li><a class="reference internal" href="#id177" id="id888">Semantics:</a></li>
+<li><a class="reference internal" href="#id178" id="id889">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#getelementptr-instruction" id="id890">‘<tt class="docutils literal"><span class="pre">getelementptr</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id179" id="id891">Syntax:</a></li>
+<li><a class="reference internal" href="#id180" id="id892">Overview:</a></li>
+<li><a class="reference internal" href="#id181" id="id893">Arguments:</a></li>
+<li><a class="reference internal" href="#id182" id="id894">Semantics:</a></li>
+<li><a class="reference internal" href="#id183" id="id895">Example:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#conversion-operations" id="id896">Conversion Operations</a><ul>
+<li><a class="reference internal" href="#trunc-to-instruction" id="id897">‘<tt class="docutils literal"><span class="pre">trunc</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id184" id="id898">Syntax:</a></li>
+<li><a class="reference internal" href="#id185" id="id899">Overview:</a></li>
+<li><a class="reference internal" href="#id186" id="id900">Arguments:</a></li>
+<li><a class="reference internal" href="#id187" id="id901">Semantics:</a></li>
+<li><a class="reference internal" href="#id188" id="id902">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#zext-to-instruction" id="id903">‘<tt class="docutils literal"><span class="pre">zext</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id189" id="id904">Syntax:</a></li>
+<li><a class="reference internal" href="#id190" id="id905">Overview:</a></li>
+<li><a class="reference internal" href="#id191" id="id906">Arguments:</a></li>
+<li><a class="reference internal" href="#id192" id="id907">Semantics:</a></li>
+<li><a class="reference internal" href="#id193" id="id908">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#sext-to-instruction" id="id909">‘<tt class="docutils literal"><span class="pre">sext</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id194" id="id910">Syntax:</a></li>
+<li><a class="reference internal" href="#id195" id="id911">Overview:</a></li>
+<li><a class="reference internal" href="#id196" id="id912">Arguments:</a></li>
+<li><a class="reference internal" href="#id197" id="id913">Semantics:</a></li>
+<li><a class="reference internal" href="#id198" id="id914">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#fptrunc-to-instruction" id="id915">‘<tt class="docutils literal"><span class="pre">fptrunc</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id199" id="id916">Syntax:</a></li>
+<li><a class="reference internal" href="#id200" id="id917">Overview:</a></li>
+<li><a class="reference internal" href="#id201" id="id918">Arguments:</a></li>
+<li><a class="reference internal" href="#id202" id="id919">Semantics:</a></li>
+<li><a class="reference internal" href="#id203" id="id920">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#fpext-to-instruction" id="id921">‘<tt class="docutils literal"><span class="pre">fpext</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id204" id="id922">Syntax:</a></li>
+<li><a class="reference internal" href="#id205" id="id923">Overview:</a></li>
+<li><a class="reference internal" href="#id206" id="id924">Arguments:</a></li>
+<li><a class="reference internal" href="#id207" id="id925">Semantics:</a></li>
+<li><a class="reference internal" href="#id208" id="id926">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#fptoui-to-instruction" id="id927">‘<tt class="docutils literal"><span class="pre">fptoui</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id209" id="id928">Syntax:</a></li>
+<li><a class="reference internal" href="#id210" id="id929">Overview:</a></li>
+<li><a class="reference internal" href="#id211" id="id930">Arguments:</a></li>
+<li><a class="reference internal" href="#id212" id="id931">Semantics:</a></li>
+<li><a class="reference internal" href="#id213" id="id932">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#fptosi-to-instruction" id="id933">‘<tt class="docutils literal"><span class="pre">fptosi</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id214" id="id934">Syntax:</a></li>
+<li><a class="reference internal" href="#id215" id="id935">Overview:</a></li>
+<li><a class="reference internal" href="#id216" id="id936">Arguments:</a></li>
+<li><a class="reference internal" href="#id217" id="id937">Semantics:</a></li>
+<li><a class="reference internal" href="#id218" id="id938">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#uitofp-to-instruction" id="id939">‘<tt class="docutils literal"><span class="pre">uitofp</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id219" id="id940">Syntax:</a></li>
+<li><a class="reference internal" href="#id220" id="id941">Overview:</a></li>
+<li><a class="reference internal" href="#id221" id="id942">Arguments:</a></li>
+<li><a class="reference internal" href="#id222" id="id943">Semantics:</a></li>
+<li><a class="reference internal" href="#id223" id="id944">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#sitofp-to-instruction" id="id945">‘<tt class="docutils literal"><span class="pre">sitofp</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id224" id="id946">Syntax:</a></li>
+<li><a class="reference internal" href="#id225" id="id947">Overview:</a></li>
+<li><a class="reference internal" href="#id226" id="id948">Arguments:</a></li>
+<li><a class="reference internal" href="#id227" id="id949">Semantics:</a></li>
+<li><a class="reference internal" href="#id228" id="id950">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#ptrtoint-to-instruction" id="id951">‘<tt class="docutils literal"><span class="pre">ptrtoint</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id229" id="id952">Syntax:</a></li>
+<li><a class="reference internal" href="#id230" id="id953">Overview:</a></li>
+<li><a class="reference internal" href="#id231" id="id954">Arguments:</a></li>
+<li><a class="reference internal" href="#id232" id="id955">Semantics:</a></li>
+<li><a class="reference internal" href="#id233" id="id956">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#inttoptr-to-instruction" id="id957">‘<tt class="docutils literal"><span class="pre">inttoptr</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id234" id="id958">Syntax:</a></li>
+<li><a class="reference internal" href="#id235" id="id959">Overview:</a></li>
+<li><a class="reference internal" href="#id236" id="id960">Arguments:</a></li>
+<li><a class="reference internal" href="#id237" id="id961">Semantics:</a></li>
+<li><a class="reference internal" href="#id238" id="id962">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#bitcast-to-instruction" id="id963">‘<tt class="docutils literal"><span class="pre">bitcast</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id239" id="id964">Syntax:</a></li>
+<li><a class="reference internal" href="#id240" id="id965">Overview:</a></li>
+<li><a class="reference internal" href="#id241" id="id966">Arguments:</a></li>
+<li><a class="reference internal" href="#id242" id="id967">Semantics:</a></li>
+<li><a class="reference internal" href="#id243" id="id968">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#addrspacecast-to-instruction" id="id969">‘<tt class="docutils literal"><span class="pre">addrspacecast</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id244" id="id970">Syntax:</a></li>
+<li><a class="reference internal" href="#id245" id="id971">Overview:</a></li>
+<li><a class="reference internal" href="#id246" id="id972">Arguments:</a></li>
+<li><a class="reference internal" href="#id247" id="id973">Semantics:</a></li>
+<li><a class="reference internal" href="#id248" id="id974">Example:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#other-operations" id="id975">Other Operations</a><ul>
+<li><a class="reference internal" href="#icmp-instruction" id="id976">‘<tt class="docutils literal"><span class="pre">icmp</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id249" id="id977">Syntax:</a></li>
+<li><a class="reference internal" href="#id250" id="id978">Overview:</a></li>
+<li><a class="reference internal" href="#id251" id="id979">Arguments:</a></li>
+<li><a class="reference internal" href="#id252" id="id980">Semantics:</a></li>
+<li><a class="reference internal" href="#id253" id="id981">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#fcmp-instruction" id="id982">‘<tt class="docutils literal"><span class="pre">fcmp</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id254" id="id983">Syntax:</a></li>
+<li><a class="reference internal" href="#id255" id="id984">Overview:</a></li>
+<li><a class="reference internal" href="#id256" id="id985">Arguments:</a></li>
+<li><a class="reference internal" href="#id257" id="id986">Semantics:</a></li>
+<li><a class="reference internal" href="#id258" id="id987">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#phi-instruction" id="id988">‘<tt class="docutils literal"><span class="pre">phi</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id259" id="id989">Syntax:</a></li>
+<li><a class="reference internal" href="#id260" id="id990">Overview:</a></li>
+<li><a class="reference internal" href="#id261" id="id991">Arguments:</a></li>
+<li><a class="reference internal" href="#id262" id="id992">Semantics:</a></li>
+<li><a class="reference internal" href="#id263" id="id993">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#select-instruction" id="id994">‘<tt class="docutils literal"><span class="pre">select</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id264" id="id995">Syntax:</a></li>
+<li><a class="reference internal" href="#id265" id="id996">Overview:</a></li>
+<li><a class="reference internal" href="#id266" id="id997">Arguments:</a></li>
+<li><a class="reference internal" href="#id267" id="id998">Semantics:</a></li>
+<li><a class="reference internal" href="#id268" id="id999">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#call-instruction" id="id1000">‘<tt class="docutils literal"><span class="pre">call</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id269" id="id1001">Syntax:</a></li>
+<li><a class="reference internal" href="#id270" id="id1002">Overview:</a></li>
+<li><a class="reference internal" href="#id271" id="id1003">Arguments:</a></li>
+<li><a class="reference internal" href="#id272" id="id1004">Semantics:</a></li>
+<li><a class="reference internal" href="#id273" id="id1005">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#va-arg-instruction" id="id1006">‘<tt class="docutils literal"><span class="pre">va_arg</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id274" id="id1007">Syntax:</a></li>
+<li><a class="reference internal" href="#id275" id="id1008">Overview:</a></li>
+<li><a class="reference internal" href="#id276" id="id1009">Arguments:</a></li>
+<li><a class="reference internal" href="#id277" id="id1010">Semantics:</a></li>
+<li><a class="reference internal" href="#id278" id="id1011">Example:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#landingpad-instruction" id="id1012">‘<tt class="docutils literal"><span class="pre">landingpad</span></tt>‘ Instruction</a><ul>
+<li><a class="reference internal" href="#id279" id="id1013">Syntax:</a></li>
+<li><a class="reference internal" href="#id280" id="id1014">Overview:</a></li>
+<li><a class="reference internal" href="#id281" id="id1015">Arguments:</a></li>
+<li><a class="reference internal" href="#id282" id="id1016">Semantics:</a></li>
+<li><a class="reference internal" href="#id283" id="id1017">Example:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#intrinsic-functions" id="id1018">Intrinsic Functions</a><ul>
+<li><a class="reference internal" href="#variable-argument-handling-intrinsics" id="id1019">Variable Argument Handling Intrinsics</a><ul>
+<li><a class="reference internal" href="#llvm-va-start-intrinsic" id="id1020">‘<tt class="docutils literal"><span class="pre">llvm.va_start</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id284" id="id1021">Syntax:</a></li>
+<li><a class="reference internal" href="#id285" id="id1022">Overview:</a></li>
+<li><a class="reference internal" href="#id286" id="id1023">Arguments:</a></li>
+<li><a class="reference internal" href="#id287" id="id1024">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-va-end-intrinsic" id="id1025">‘<tt class="docutils literal"><span class="pre">llvm.va_end</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id288" id="id1026">Syntax:</a></li>
+<li><a class="reference internal" href="#id289" id="id1027">Overview:</a></li>
+<li><a class="reference internal" href="#id290" id="id1028">Arguments:</a></li>
+<li><a class="reference internal" href="#id291" id="id1029">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-va-copy-intrinsic" id="id1030">‘<tt class="docutils literal"><span class="pre">llvm.va_copy</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id292" id="id1031">Syntax:</a></li>
+<li><a class="reference internal" href="#id293" id="id1032">Overview:</a></li>
+<li><a class="reference internal" href="#id294" id="id1033">Arguments:</a></li>
+<li><a class="reference internal" href="#id295" id="id1034">Semantics:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#accurate-garbage-collection-intrinsics" id="id1035">Accurate Garbage Collection Intrinsics</a><ul>
+<li><a class="reference internal" href="#llvm-gcroot-intrinsic" id="id1036">‘<tt class="docutils literal"><span class="pre">llvm.gcroot</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id296" id="id1037">Syntax:</a></li>
+<li><a class="reference internal" href="#id297" id="id1038">Overview:</a></li>
+<li><a class="reference internal" href="#id298" id="id1039">Arguments:</a></li>
+<li><a class="reference internal" href="#id299" id="id1040">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-gcread-intrinsic" id="id1041">‘<tt class="docutils literal"><span class="pre">llvm.gcread</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id300" id="id1042">Syntax:</a></li>
+<li><a class="reference internal" href="#id301" id="id1043">Overview:</a></li>
+<li><a class="reference internal" href="#id302" id="id1044">Arguments:</a></li>
+<li><a class="reference internal" href="#id303" id="id1045">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-gcwrite-intrinsic" id="id1046">‘<tt class="docutils literal"><span class="pre">llvm.gcwrite</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id304" id="id1047">Syntax:</a></li>
+<li><a class="reference internal" href="#id305" id="id1048">Overview:</a></li>
+<li><a class="reference internal" href="#id306" id="id1049">Arguments:</a></li>
+<li><a class="reference internal" href="#id307" id="id1050">Semantics:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#code-generator-intrinsics" id="id1051">Code Generator Intrinsics</a><ul>
+<li><a class="reference internal" href="#llvm-returnaddress-intrinsic" id="id1052">‘<tt class="docutils literal"><span class="pre">llvm.returnaddress</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id308" id="id1053">Syntax:</a></li>
+<li><a class="reference internal" href="#id309" id="id1054">Overview:</a></li>
+<li><a class="reference internal" href="#id310" id="id1055">Arguments:</a></li>
+<li><a class="reference internal" href="#id311" id="id1056">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-frameaddress-intrinsic" id="id1057">‘<tt class="docutils literal"><span class="pre">llvm.frameaddress</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id312" id="id1058">Syntax:</a></li>
+<li><a class="reference internal" href="#id313" id="id1059">Overview:</a></li>
+<li><a class="reference internal" href="#id314" id="id1060">Arguments:</a></li>
+<li><a class="reference internal" href="#id315" id="id1061">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-frameallocate-and-llvm-framerecover-intrinsics" id="id1062">‘<tt class="docutils literal"><span class="pre">llvm.frameallocate</span></tt>‘ and ‘<tt class="docutils literal"><span class="pre">llvm.framerecover</span></tt>‘ Intrinsics</a><ul>
+<li><a class="reference internal" href="#id316" id="id1063">Syntax:</a></li>
+<li><a class="reference internal" href="#id317" id="id1064">Overview:</a></li>
+<li><a class="reference internal" href="#id318" id="id1065">Arguments:</a></li>
+<li><a class="reference internal" href="#id319" id="id1066">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-read-register-and-llvm-write-register-intrinsics" id="id1067">‘<tt class="docutils literal"><span class="pre">llvm.read_register</span></tt>‘ and ‘<tt class="docutils literal"><span class="pre">llvm.write_register</span></tt>‘ Intrinsics</a><ul>
+<li><a class="reference internal" href="#id320" id="id1068">Syntax:</a></li>
+<li><a class="reference internal" href="#id321" id="id1069">Overview:</a></li>
+<li><a class="reference internal" href="#id322" id="id1070">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-stacksave-intrinsic" id="id1071">‘<tt class="docutils literal"><span class="pre">llvm.stacksave</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id323" id="id1072">Syntax:</a></li>
+<li><a class="reference internal" href="#id324" id="id1073">Overview:</a></li>
+<li><a class="reference internal" href="#id325" id="id1074">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-stackrestore-intrinsic" id="id1075">‘<tt class="docutils literal"><span class="pre">llvm.stackrestore</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id326" id="id1076">Syntax:</a></li>
+<li><a class="reference internal" href="#id327" id="id1077">Overview:</a></li>
+<li><a class="reference internal" href="#id328" id="id1078">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-prefetch-intrinsic" id="id1079">‘<tt class="docutils literal"><span class="pre">llvm.prefetch</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id329" id="id1080">Syntax:</a></li>
+<li><a class="reference internal" href="#id330" id="id1081">Overview:</a></li>
+<li><a class="reference internal" href="#id331" id="id1082">Arguments:</a></li>
+<li><a class="reference internal" href="#id332" id="id1083">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-pcmarker-intrinsic" id="id1084">‘<tt class="docutils literal"><span class="pre">llvm.pcmarker</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id333" id="id1085">Syntax:</a></li>
+<li><a class="reference internal" href="#id334" id="id1086">Overview:</a></li>
+<li><a class="reference internal" href="#id335" id="id1087">Arguments:</a></li>
+<li><a class="reference internal" href="#id336" id="id1088">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-readcyclecounter-intrinsic" id="id1089">‘<tt class="docutils literal"><span class="pre">llvm.readcyclecounter</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id337" id="id1090">Syntax:</a></li>
+<li><a class="reference internal" href="#id338" id="id1091">Overview:</a></li>
+<li><a class="reference internal" href="#id339" id="id1092">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-clear-cache-intrinsic" id="id1093">‘<tt class="docutils literal"><span class="pre">llvm.clear_cache</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id340" id="id1094">Syntax:</a></li>
+<li><a class="reference internal" href="#id341" id="id1095">Overview:</a></li>
+<li><a class="reference internal" href="#id342" id="id1096">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-instrprof-increment-intrinsic" id="id1097">‘<tt class="docutils literal"><span class="pre">llvm.instrprof_increment</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id343" id="id1098">Syntax:</a></li>
+<li><a class="reference internal" href="#id344" id="id1099">Overview:</a></li>
+<li><a class="reference internal" href="#id345" id="id1100">Arguments:</a></li>
+<li><a class="reference internal" href="#id346" id="id1101">Semantics:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#standard-c-library-intrinsics" id="id1102">Standard C Library Intrinsics</a><ul>
+<li><a class="reference internal" href="#llvm-memcpy-intrinsic" id="id1103">‘<tt class="docutils literal"><span class="pre">llvm.memcpy</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id347" id="id1104">Syntax:</a></li>
+<li><a class="reference internal" href="#id348" id="id1105">Overview:</a></li>
+<li><a class="reference internal" href="#id349" id="id1106">Arguments:</a></li>
+<li><a class="reference internal" href="#id350" id="id1107">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-memmove-intrinsic" id="id1108">‘<tt class="docutils literal"><span class="pre">llvm.memmove</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id351" id="id1109">Syntax:</a></li>
+<li><a class="reference internal" href="#id352" id="id1110">Overview:</a></li>
+<li><a class="reference internal" href="#id353" id="id1111">Arguments:</a></li>
+<li><a class="reference internal" href="#id354" id="id1112">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-memset-intrinsics" id="id1113">‘<tt class="docutils literal"><span class="pre">llvm.memset.*</span></tt>‘ Intrinsics</a><ul>
+<li><a class="reference internal" href="#id355" id="id1114">Syntax:</a></li>
+<li><a class="reference internal" href="#id356" id="id1115">Overview:</a></li>
+<li><a class="reference internal" href="#id357" id="id1116">Arguments:</a></li>
+<li><a class="reference internal" href="#id358" id="id1117">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-sqrt-intrinsic" id="id1118">‘<tt class="docutils literal"><span class="pre">llvm.sqrt.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id359" id="id1119">Syntax:</a></li>
+<li><a class="reference internal" href="#id360" id="id1120">Overview:</a></li>
+<li><a class="reference internal" href="#id361" id="id1121">Arguments:</a></li>
+<li><a class="reference internal" href="#id362" id="id1122">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-powi-intrinsic" id="id1123">‘<tt class="docutils literal"><span class="pre">llvm.powi.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id363" id="id1124">Syntax:</a></li>
+<li><a class="reference internal" href="#id364" id="id1125">Overview:</a></li>
+<li><a class="reference internal" href="#id365" id="id1126">Arguments:</a></li>
+<li><a class="reference internal" href="#id366" id="id1127">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-sin-intrinsic" id="id1128">‘<tt class="docutils literal"><span class="pre">llvm.sin.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id367" id="id1129">Syntax:</a></li>
+<li><a class="reference internal" href="#id368" id="id1130">Overview:</a></li>
+<li><a class="reference internal" href="#id369" id="id1131">Arguments:</a></li>
+<li><a class="reference internal" href="#id370" id="id1132">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-cos-intrinsic" id="id1133">‘<tt class="docutils literal"><span class="pre">llvm.cos.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id371" id="id1134">Syntax:</a></li>
+<li><a class="reference internal" href="#id372" id="id1135">Overview:</a></li>
+<li><a class="reference internal" href="#id373" id="id1136">Arguments:</a></li>
+<li><a class="reference internal" href="#id374" id="id1137">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-pow-intrinsic" id="id1138">‘<tt class="docutils literal"><span class="pre">llvm.pow.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id375" id="id1139">Syntax:</a></li>
+<li><a class="reference internal" href="#id376" id="id1140">Overview:</a></li>
+<li><a class="reference internal" href="#id377" id="id1141">Arguments:</a></li>
+<li><a class="reference internal" href="#id378" id="id1142">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-exp-intrinsic" id="id1143">‘<tt class="docutils literal"><span class="pre">llvm.exp.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id379" id="id1144">Syntax:</a></li>
+<li><a class="reference internal" href="#id380" id="id1145">Overview:</a></li>
+<li><a class="reference internal" href="#id381" id="id1146">Arguments:</a></li>
+<li><a class="reference internal" href="#id382" id="id1147">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-exp2-intrinsic" id="id1148">‘<tt class="docutils literal"><span class="pre">llvm.exp2.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id383" id="id1149">Syntax:</a></li>
+<li><a class="reference internal" href="#id384" id="id1150">Overview:</a></li>
+<li><a class="reference internal" href="#id385" id="id1151">Arguments:</a></li>
+<li><a class="reference internal" href="#id386" id="id1152">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-log-intrinsic" id="id1153">‘<tt class="docutils literal"><span class="pre">llvm.log.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id387" id="id1154">Syntax:</a></li>
+<li><a class="reference internal" href="#id388" id="id1155">Overview:</a></li>
+<li><a class="reference internal" href="#id389" id="id1156">Arguments:</a></li>
+<li><a class="reference internal" href="#id390" id="id1157">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-log10-intrinsic" id="id1158">‘<tt class="docutils literal"><span class="pre">llvm.log10.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id391" id="id1159">Syntax:</a></li>
+<li><a class="reference internal" href="#id392" id="id1160">Overview:</a></li>
+<li><a class="reference internal" href="#id393" id="id1161">Arguments:</a></li>
+<li><a class="reference internal" href="#id394" id="id1162">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-log2-intrinsic" id="id1163">‘<tt class="docutils literal"><span class="pre">llvm.log2.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id395" id="id1164">Syntax:</a></li>
+<li><a class="reference internal" href="#id396" id="id1165">Overview:</a></li>
+<li><a class="reference internal" href="#id397" id="id1166">Arguments:</a></li>
+<li><a class="reference internal" href="#id398" id="id1167">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-fma-intrinsic" id="id1168">‘<tt class="docutils literal"><span class="pre">llvm.fma.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id399" id="id1169">Syntax:</a></li>
+<li><a class="reference internal" href="#id400" id="id1170">Overview:</a></li>
+<li><a class="reference internal" href="#id401" id="id1171">Arguments:</a></li>
+<li><a class="reference internal" href="#id402" id="id1172">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-fabs-intrinsic" id="id1173">‘<tt class="docutils literal"><span class="pre">llvm.fabs.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id403" id="id1174">Syntax:</a></li>
+<li><a class="reference internal" href="#id404" id="id1175">Overview:</a></li>
+<li><a class="reference internal" href="#id405" id="id1176">Arguments:</a></li>
+<li><a class="reference internal" href="#id406" id="id1177">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-minnum-intrinsic" id="id1178">‘<tt class="docutils literal"><span class="pre">llvm.minnum.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id407" id="id1179">Syntax:</a></li>
+<li><a class="reference internal" href="#id408" id="id1180">Overview:</a></li>
+<li><a class="reference internal" href="#id409" id="id1181">Arguments:</a></li>
+<li><a class="reference internal" href="#id410" id="id1182">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-maxnum-intrinsic" id="id1183">‘<tt class="docutils literal"><span class="pre">llvm.maxnum.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id411" id="id1184">Syntax:</a></li>
+<li><a class="reference internal" href="#id412" id="id1185">Overview:</a></li>
+<li><a class="reference internal" href="#id413" id="id1186">Arguments:</a></li>
+<li><a class="reference internal" href="#id414" id="id1187">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-copysign-intrinsic" id="id1188">‘<tt class="docutils literal"><span class="pre">llvm.copysign.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id415" id="id1189">Syntax:</a></li>
+<li><a class="reference internal" href="#id416" id="id1190">Overview:</a></li>
+<li><a class="reference internal" href="#id417" id="id1191">Arguments:</a></li>
+<li><a class="reference internal" href="#id418" id="id1192">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-floor-intrinsic" id="id1193">‘<tt class="docutils literal"><span class="pre">llvm.floor.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id419" id="id1194">Syntax:</a></li>
+<li><a class="reference internal" href="#id420" id="id1195">Overview:</a></li>
+<li><a class="reference internal" href="#id421" id="id1196">Arguments:</a></li>
+<li><a class="reference internal" href="#id422" id="id1197">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-ceil-intrinsic" id="id1198">‘<tt class="docutils literal"><span class="pre">llvm.ceil.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id423" id="id1199">Syntax:</a></li>
+<li><a class="reference internal" href="#id424" id="id1200">Overview:</a></li>
+<li><a class="reference internal" href="#id425" id="id1201">Arguments:</a></li>
+<li><a class="reference internal" href="#id426" id="id1202">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-trunc-intrinsic" id="id1203">‘<tt class="docutils literal"><span class="pre">llvm.trunc.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id427" id="id1204">Syntax:</a></li>
+<li><a class="reference internal" href="#id428" id="id1205">Overview:</a></li>
+<li><a class="reference internal" href="#id429" id="id1206">Arguments:</a></li>
+<li><a class="reference internal" href="#id430" id="id1207">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-rint-intrinsic" id="id1208">‘<tt class="docutils literal"><span class="pre">llvm.rint.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id431" id="id1209">Syntax:</a></li>
+<li><a class="reference internal" href="#id432" id="id1210">Overview:</a></li>
+<li><a class="reference internal" href="#id433" id="id1211">Arguments:</a></li>
+<li><a class="reference internal" href="#id434" id="id1212">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-nearbyint-intrinsic" id="id1213">‘<tt class="docutils literal"><span class="pre">llvm.nearbyint.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id435" id="id1214">Syntax:</a></li>
+<li><a class="reference internal" href="#id436" id="id1215">Overview:</a></li>
+<li><a class="reference internal" href="#id437" id="id1216">Arguments:</a></li>
+<li><a class="reference internal" href="#id438" id="id1217">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-round-intrinsic" id="id1218">‘<tt class="docutils literal"><span class="pre">llvm.round.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id439" id="id1219">Syntax:</a></li>
+<li><a class="reference internal" href="#id440" id="id1220">Overview:</a></li>
+<li><a class="reference internal" href="#id441" id="id1221">Arguments:</a></li>
+<li><a class="reference internal" href="#id442" id="id1222">Semantics:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#bit-manipulation-intrinsics" id="id1223">Bit Manipulation Intrinsics</a><ul>
+<li><a class="reference internal" href="#llvm-bswap-intrinsics" id="id1224">‘<tt class="docutils literal"><span class="pre">llvm.bswap.*</span></tt>‘ Intrinsics</a><ul>
+<li><a class="reference internal" href="#id443" id="id1225">Syntax:</a></li>
+<li><a class="reference internal" href="#id444" id="id1226">Overview:</a></li>
+<li><a class="reference internal" href="#id445" id="id1227">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-ctpop-intrinsic" id="id1228">‘<tt class="docutils literal"><span class="pre">llvm.ctpop.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id446" id="id1229">Syntax:</a></li>
+<li><a class="reference internal" href="#id447" id="id1230">Overview:</a></li>
+<li><a class="reference internal" href="#id448" id="id1231">Arguments:</a></li>
+<li><a class="reference internal" href="#id449" id="id1232">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-ctlz-intrinsic" id="id1233">‘<tt class="docutils literal"><span class="pre">llvm.ctlz.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id450" id="id1234">Syntax:</a></li>
+<li><a class="reference internal" href="#id451" id="id1235">Overview:</a></li>
+<li><a class="reference internal" href="#id452" id="id1236">Arguments:</a></li>
+<li><a class="reference internal" href="#id453" id="id1237">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-cttz-intrinsic" id="id1238">‘<tt class="docutils literal"><span class="pre">llvm.cttz.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id454" id="id1239">Syntax:</a></li>
+<li><a class="reference internal" href="#id455" id="id1240">Overview:</a></li>
+<li><a class="reference internal" href="#id456" id="id1241">Arguments:</a></li>
+<li><a class="reference internal" href="#id457" id="id1242">Semantics:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#arithmetic-with-overflow-intrinsics" id="id1243">Arithmetic with Overflow Intrinsics</a><ul>
+<li><a class="reference internal" href="#llvm-sadd-with-overflow-intrinsics" id="id1244">‘<tt class="docutils literal"><span class="pre">llvm.sadd.with.overflow.*</span></tt>‘ Intrinsics</a><ul>
+<li><a class="reference internal" href="#id458" id="id1245">Syntax:</a></li>
+<li><a class="reference internal" href="#id459" id="id1246">Overview:</a></li>
+<li><a class="reference internal" href="#id460" id="id1247">Arguments:</a></li>
+<li><a class="reference internal" href="#id461" id="id1248">Semantics:</a></li>
+<li><a class="reference internal" href="#id462" id="id1249">Examples:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-uadd-with-overflow-intrinsics" id="id1250">‘<tt class="docutils literal"><span class="pre">llvm.uadd.with.overflow.*</span></tt>‘ Intrinsics</a><ul>
+<li><a class="reference internal" href="#id463" id="id1251">Syntax:</a></li>
+<li><a class="reference internal" href="#id464" id="id1252">Overview:</a></li>
+<li><a class="reference internal" href="#id465" id="id1253">Arguments:</a></li>
+<li><a class="reference internal" href="#id466" id="id1254">Semantics:</a></li>
+<li><a class="reference internal" href="#id467" id="id1255">Examples:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-ssub-with-overflow-intrinsics" id="id1256">‘<tt class="docutils literal"><span class="pre">llvm.ssub.with.overflow.*</span></tt>‘ Intrinsics</a><ul>
+<li><a class="reference internal" href="#id468" id="id1257">Syntax:</a></li>
+<li><a class="reference internal" href="#id469" id="id1258">Overview:</a></li>
+<li><a class="reference internal" href="#id470" id="id1259">Arguments:</a></li>
+<li><a class="reference internal" href="#id471" id="id1260">Semantics:</a></li>
+<li><a class="reference internal" href="#id472" id="id1261">Examples:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-usub-with-overflow-intrinsics" id="id1262">‘<tt class="docutils literal"><span class="pre">llvm.usub.with.overflow.*</span></tt>‘ Intrinsics</a><ul>
+<li><a class="reference internal" href="#id473" id="id1263">Syntax:</a></li>
+<li><a class="reference internal" href="#id474" id="id1264">Overview:</a></li>
+<li><a class="reference internal" href="#id475" id="id1265">Arguments:</a></li>
+<li><a class="reference internal" href="#id476" id="id1266">Semantics:</a></li>
+<li><a class="reference internal" href="#id477" id="id1267">Examples:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-smul-with-overflow-intrinsics" id="id1268">‘<tt class="docutils literal"><span class="pre">llvm.smul.with.overflow.*</span></tt>‘ Intrinsics</a><ul>
+<li><a class="reference internal" href="#id478" id="id1269">Syntax:</a></li>
+<li><a class="reference internal" href="#id479" id="id1270">Overview:</a></li>
+<li><a class="reference internal" href="#id480" id="id1271">Arguments:</a></li>
+<li><a class="reference internal" href="#id481" id="id1272">Semantics:</a></li>
+<li><a class="reference internal" href="#id482" id="id1273">Examples:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-umul-with-overflow-intrinsics" id="id1274">‘<tt class="docutils literal"><span class="pre">llvm.umul.with.overflow.*</span></tt>‘ Intrinsics</a><ul>
+<li><a class="reference internal" href="#id483" id="id1275">Syntax:</a></li>
+<li><a class="reference internal" href="#id484" id="id1276">Overview:</a></li>
+<li><a class="reference internal" href="#id485" id="id1277">Arguments:</a></li>
+<li><a class="reference internal" href="#id486" id="id1278">Semantics:</a></li>
+<li><a class="reference internal" href="#id487" id="id1279">Examples:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#specialised-arithmetic-intrinsics" id="id1280">Specialised Arithmetic Intrinsics</a><ul>
+<li><a class="reference internal" href="#llvm-fmuladd-intrinsic" id="id1281">‘<tt class="docutils literal"><span class="pre">llvm.fmuladd.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id488" id="id1282">Syntax:</a></li>
+<li><a class="reference internal" href="#id489" id="id1283">Overview:</a></li>
+<li><a class="reference internal" href="#id490" id="id1284">Arguments:</a></li>
+<li><a class="reference internal" href="#id491" id="id1285">Semantics:</a></li>
+<li><a class="reference internal" href="#id492" id="id1286">Examples:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#half-precision-floating-point-intrinsics" id="id1287">Half Precision Floating Point Intrinsics</a><ul>
+<li><a class="reference internal" href="#llvm-convert-to-fp16-intrinsic" id="id1288">‘<tt class="docutils literal"><span class="pre">llvm.convert.to.fp16</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id493" id="id1289">Syntax:</a></li>
+<li><a class="reference internal" href="#id494" id="id1290">Overview:</a></li>
+<li><a class="reference internal" href="#id495" id="id1291">Arguments:</a></li>
+<li><a class="reference internal" href="#id496" id="id1292">Semantics:</a></li>
+<li><a class="reference internal" href="#id497" id="id1293">Examples:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-convert-from-fp16-intrinsic" id="id1294">‘<tt class="docutils literal"><span class="pre">llvm.convert.from.fp16</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id498" id="id1295">Syntax:</a></li>
+<li><a class="reference internal" href="#id499" id="id1296">Overview:</a></li>
+<li><a class="reference internal" href="#id500" id="id1297">Arguments:</a></li>
+<li><a class="reference internal" href="#id501" id="id1298">Semantics:</a></li>
+<li><a class="reference internal" href="#id502" id="id1299">Examples:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#debugger-intrinsics" id="id1300">Debugger Intrinsics</a></li>
+<li><a class="reference internal" href="#exception-handling-intrinsics" id="id1301">Exception Handling Intrinsics</a></li>
+<li><a class="reference internal" href="#trampoline-intrinsics" id="id1302">Trampoline Intrinsics</a><ul>
+<li><a class="reference internal" href="#llvm-init-trampoline-intrinsic" id="id1303">‘<tt class="docutils literal"><span class="pre">llvm.init.trampoline</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id503" id="id1304">Syntax:</a></li>
+<li><a class="reference internal" href="#id504" id="id1305">Overview:</a></li>
+<li><a class="reference internal" href="#id505" id="id1306">Arguments:</a></li>
+<li><a class="reference internal" href="#id506" id="id1307">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-adjust-trampoline-intrinsic" id="id1308">‘<tt class="docutils literal"><span class="pre">llvm.adjust.trampoline</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id507" id="id1309">Syntax:</a></li>
+<li><a class="reference internal" href="#id508" id="id1310">Overview:</a></li>
+<li><a class="reference internal" href="#id509" id="id1311">Arguments:</a></li>
+<li><a class="reference internal" href="#id510" id="id1312">Semantics:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#masked-vector-load-and-store-intrinsics" id="id1313">Masked Vector Load and Store Intrinsics</a><ul>
+<li><a class="reference internal" href="#llvm-masked-load-intrinsics" id="id1314">‘<tt class="docutils literal"><span class="pre">llvm.masked.load.*</span></tt>‘ Intrinsics</a><ul>
+<li><a class="reference internal" href="#id511" id="id1315">Syntax:</a></li>
+<li><a class="reference internal" href="#id512" id="id1316">Overview:</a></li>
+<li><a class="reference internal" href="#id513" id="id1317">Arguments:</a></li>
+<li><a class="reference internal" href="#id514" id="id1318">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-masked-store-intrinsics" id="id1319">‘<tt class="docutils literal"><span class="pre">llvm.masked.store.*</span></tt>‘ Intrinsics</a><ul>
+<li><a class="reference internal" href="#id515" id="id1320">Syntax:</a></li>
+<li><a class="reference internal" href="#id516" id="id1321">Overview:</a></li>
+<li><a class="reference internal" href="#id517" id="id1322">Arguments:</a></li>
+<li><a class="reference internal" href="#id518" id="id1323">Semantics:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#memory-use-markers" id="id1324">Memory Use Markers</a><ul>
+<li><a class="reference internal" href="#llvm-lifetime-start-intrinsic" id="id1325">‘<tt class="docutils literal"><span class="pre">llvm.lifetime.start</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id519" id="id1326">Syntax:</a></li>
+<li><a class="reference internal" href="#id520" id="id1327">Overview:</a></li>
+<li><a class="reference internal" href="#id521" id="id1328">Arguments:</a></li>
+<li><a class="reference internal" href="#id522" id="id1329">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-lifetime-end-intrinsic" id="id1330">‘<tt class="docutils literal"><span class="pre">llvm.lifetime.end</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id523" id="id1331">Syntax:</a></li>
+<li><a class="reference internal" href="#id524" id="id1332">Overview:</a></li>
+<li><a class="reference internal" href="#id525" id="id1333">Arguments:</a></li>
+<li><a class="reference internal" href="#id526" id="id1334">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-invariant-start-intrinsic" id="id1335">‘<tt class="docutils literal"><span class="pre">llvm.invariant.start</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id527" id="id1336">Syntax:</a></li>
+<li><a class="reference internal" href="#id528" id="id1337">Overview:</a></li>
+<li><a class="reference internal" href="#id529" id="id1338">Arguments:</a></li>
+<li><a class="reference internal" href="#id530" id="id1339">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-invariant-end-intrinsic" id="id1340">‘<tt class="docutils literal"><span class="pre">llvm.invariant.end</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id531" id="id1341">Syntax:</a></li>
+<li><a class="reference internal" href="#id532" id="id1342">Overview:</a></li>
+<li><a class="reference internal" href="#id533" id="id1343">Arguments:</a></li>
+<li><a class="reference internal" href="#id534" id="id1344">Semantics:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#general-intrinsics" id="id1345">General Intrinsics</a><ul>
+<li><a class="reference internal" href="#llvm-var-annotation-intrinsic" id="id1346">‘<tt class="docutils literal"><span class="pre">llvm.var.annotation</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id535" id="id1347">Syntax:</a></li>
+<li><a class="reference internal" href="#id536" id="id1348">Overview:</a></li>
+<li><a class="reference internal" href="#id537" id="id1349">Arguments:</a></li>
+<li><a class="reference internal" href="#id538" id="id1350">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-ptr-annotation-intrinsic" id="id1351">‘<tt class="docutils literal"><span class="pre">llvm.ptr.annotation.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id539" id="id1352">Syntax:</a></li>
+<li><a class="reference internal" href="#id540" id="id1353">Overview:</a></li>
+<li><a class="reference internal" href="#id541" id="id1354">Arguments:</a></li>
+<li><a class="reference internal" href="#id542" id="id1355">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-annotation-intrinsic" id="id1356">‘<tt class="docutils literal"><span class="pre">llvm.annotation.*</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id543" id="id1357">Syntax:</a></li>
+<li><a class="reference internal" href="#id544" id="id1358">Overview:</a></li>
+<li><a class="reference internal" href="#id545" id="id1359">Arguments:</a></li>
+<li><a class="reference internal" href="#id546" id="id1360">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-trap-intrinsic" id="id1361">‘<tt class="docutils literal"><span class="pre">llvm.trap</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id547" id="id1362">Syntax:</a></li>
+<li><a class="reference internal" href="#id548" id="id1363">Overview:</a></li>
+<li><a class="reference internal" href="#id549" id="id1364">Arguments:</a></li>
+<li><a class="reference internal" href="#id550" id="id1365">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-debugtrap-intrinsic" id="id1366">‘<tt class="docutils literal"><span class="pre">llvm.debugtrap</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id551" id="id1367">Syntax:</a></li>
+<li><a class="reference internal" href="#id552" id="id1368">Overview:</a></li>
+<li><a class="reference internal" href="#id553" id="id1369">Arguments:</a></li>
+<li><a class="reference internal" href="#id554" id="id1370">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-stackprotector-intrinsic" id="id1371">‘<tt class="docutils literal"><span class="pre">llvm.stackprotector</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id555" id="id1372">Syntax:</a></li>
+<li><a class="reference internal" href="#id556" id="id1373">Overview:</a></li>
+<li><a class="reference internal" href="#id557" id="id1374">Arguments:</a></li>
+<li><a class="reference internal" href="#id558" id="id1375">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-stackprotectorcheck-intrinsic" id="id1376">‘<tt class="docutils literal"><span class="pre">llvm.stackprotectorcheck</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id559" id="id1377">Syntax:</a></li>
+<li><a class="reference internal" href="#id560" id="id1378">Overview:</a></li>
+<li><a class="reference internal" href="#id561" id="id1379">Arguments:</a></li>
+<li><a class="reference internal" href="#id562" id="id1380">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-objectsize-intrinsic" id="id1381">‘<tt class="docutils literal"><span class="pre">llvm.objectsize</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id563" id="id1382">Syntax:</a></li>
+<li><a class="reference internal" href="#id564" id="id1383">Overview:</a></li>
+<li><a class="reference internal" href="#id565" id="id1384">Arguments:</a></li>
+<li><a class="reference internal" href="#id566" id="id1385">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-expect-intrinsic" id="id1386">‘<tt class="docutils literal"><span class="pre">llvm.expect</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id567" id="id1387">Syntax:</a></li>
+<li><a class="reference internal" href="#id568" id="id1388">Overview:</a></li>
+<li><a class="reference internal" href="#id569" id="id1389">Arguments:</a></li>
+<li><a class="reference internal" href="#id570" id="id1390">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-assume-intrinsic" id="id1391">‘<tt class="docutils literal"><span class="pre">llvm.assume</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id571" id="id1392">Syntax:</a></li>
+<li><a class="reference internal" href="#id572" id="id1393">Overview:</a></li>
+<li><a class="reference internal" href="#id573" id="id1394">Arguments:</a></li>
+<li><a class="reference internal" href="#id574" id="id1395">Semantics:</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#llvm-donothing-intrinsic" id="id1396">‘<tt class="docutils literal"><span class="pre">llvm.donothing</span></tt>‘ Intrinsic</a><ul>
+<li><a class="reference internal" href="#id575" id="id1397">Syntax:</a></li>
+<li><a class="reference internal" href="#id576" id="id1398">Overview:</a></li>
+<li><a class="reference internal" href="#id577" id="id1399">Arguments:</a></li>
+<li><a class="reference internal" href="#id578" id="id1400">Semantics:</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#stack-map-intrinsics" id="id1401">Stack Map Intrinsics</a></li>
+</ul>
+</li>
+</ul>
+</div>
+<div class="section" id="abstract">
+<h2><a class="toc-backref" href="#id579">Abstract</a><a class="headerlink" href="#abstract" title="Permalink to this headline">¶</a></h2>
+<p>This document is a reference manual for the LLVM assembly language. LLVM
+is a Static Single Assignment (SSA) based representation that provides
+type safety, low-level operations, flexibility, and the capability of
+representing ‘all’ high-level languages cleanly. It is the common code
+representation used throughout all phases of the LLVM compilation
+strategy.</p>
+</div>
+<div class="section" id="introduction">
+<h2><a class="toc-backref" href="#id580">Introduction</a><a class="headerlink" href="#introduction" title="Permalink to this headline">¶</a></h2>
+<p>The LLVM code representation is designed to be used in three different
+forms: as an in-memory compiler IR, as an on-disk bitcode representation
+(suitable for fast loading by a Just-In-Time compiler), and as a human
+readable assembly language representation. This allows LLVM to provide a
+powerful intermediate representation for efficient compiler
+transformations and analysis, while providing a natural means to debug
+and visualize the transformations. The three different forms of LLVM are
+all equivalent. This document describes the human readable
+representation and notation.</p>
+<p>The LLVM representation aims to be light-weight and low-level while
+being expressive, typed, and extensible at the same time. It aims to be
+a “universal IR” of sorts, by being at a low enough level that
+high-level ideas may be cleanly mapped to it (similar to how
+microprocessors are “universal IR’s”, allowing many source languages to
+be mapped to them). By providing type information, LLVM can be used as
+the target of optimizations: for example, through pointer analysis, it
+can be proven that a C automatic variable is never accessed outside of
+the current function, allowing it to be promoted to a simple SSA value
+instead of a memory location.</p>
+<div class="section" id="well-formedness">
+<span id="wellformed"></span><h3><a class="toc-backref" href="#id581">Well-Formedness</a><a class="headerlink" href="#well-formedness" title="Permalink to this headline">¶</a></h3>
+<p>It is important to note that this document describes ‘well formed’ LLVM
+assembly language. There is a difference between what the parser accepts
+and what is considered ‘well formed’. For example, the following
+instruction is syntactically okay, but not well formed:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%x</span> <span class="p">=</span> <span class="k">add</span> <span class="k">i32</span> <span class="m">1</span><span class="p">,</span> <span class="nv">%x</span>
+</pre></div>
+</div>
+<p>because the definition of <tt class="docutils literal"><span class="pre">%x</span></tt> does not dominate all of its uses. The
+LLVM infrastructure provides a verification pass that may be used to
+verify that an LLVM module is well formed. This pass is automatically
+run by the parser after parsing input assembly and by the optimizer
+before it outputs bitcode. The violations pointed out by the verifier
+pass indicate bugs in transformation passes or input to the parser.</p>
+</div>
+</div>
+<div class="section" id="identifiers">
+<span id="id1"></span><h2><a class="toc-backref" href="#id582">Identifiers</a><a class="headerlink" href="#identifiers" title="Permalink to this headline">¶</a></h2>
+<p>LLVM identifiers come in two basic types: global and local. Global
+identifiers (functions, global variables) begin with the <tt class="docutils literal"><span class="pre">'@'</span></tt>
+character. Local identifiers (register names, types) begin with the
+<tt class="docutils literal"><span class="pre">'%'</span></tt> character. Additionally, there are three different formats for
+identifiers, for different purposes:</p>
+<ol class="arabic simple">
+<li>Named values are represented as a string of characters with their
+prefix. For example, <tt class="docutils literal"><span class="pre">%foo</span></tt>, <tt class="docutils literal"><span class="pre">@DivisionByZero</span></tt>,
+<tt class="docutils literal"><span class="pre">%a.really.long.identifier</span></tt>. The actual regular expression used is
+‘<tt class="docutils literal"><span class="pre">[%@][-a-zA-Z$._][-a-zA-Z$._0-9]*</span></tt>‘. Identifiers that require other
+characters in their names can be surrounded with quotes. Special
+characters may be escaped using <tt class="docutils literal"><span class="pre">"\xx"</span></tt> where <tt class="docutils literal"><span class="pre">xx</span></tt> is the ASCII
+code for the character in hexadecimal. In this way, any character can
+be used in a name value, even quotes themselves. The <tt class="docutils literal"><span class="pre">"\01"</span></tt> prefix
+can be used on global variables to suppress mangling.</li>
+<li>Unnamed values are represented as an unsigned numeric value with
+their prefix. For example, <tt class="docutils literal"><span class="pre">%12</span></tt>, <tt class="docutils literal"><span class="pre">@2</span></tt>, <tt class="docutils literal"><span class="pre">%44</span></tt>.</li>
+<li>Constants, which are described in the section  <a class="reference internal" href="#constants">Constants</a> below.</li>
+</ol>
+<p>LLVM requires that values start with a prefix for two reasons: Compilers
+don’t need to worry about name clashes with reserved words, and the set
+of reserved words may be expanded in the future without penalty.
+Additionally, unnamed identifiers allow a compiler to quickly come up
+with a temporary variable without having to avoid symbol table
+conflicts.</p>
+<p>Reserved words in LLVM are very similar to reserved words in other
+languages. There are keywords for different opcodes (‘<tt class="docutils literal"><span class="pre">add</span></tt>‘,
+‘<tt class="docutils literal"><span class="pre">bitcast</span></tt>‘, ‘<tt class="docutils literal"><span class="pre">ret</span></tt>‘, etc...), for primitive type names (‘<tt class="docutils literal"><span class="pre">void</span></tt>‘,
+‘<tt class="docutils literal"><span class="pre">i32</span></tt>‘, etc...), and others. These reserved words cannot conflict
+with variable names, because none of them start with a prefix character
+(<tt class="docutils literal"><span class="pre">'%'</span></tt> or <tt class="docutils literal"><span class="pre">'@'</span></tt>).</p>
+<p>Here is an example of LLVM code to multiply the integer variable
+‘<tt class="docutils literal"><span class="pre">%X</span></tt>‘ by 8:</p>
+<p>The easy way:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%result</span> <span class="p">=</span> <span class="k">mul</span> <span class="k">i32</span> <span class="nv">%X</span><span class="p">,</span> <span class="m">8</span>
+</pre></div>
+</div>
+<p>After strength reduction:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%result</span> <span class="p">=</span> <span class="k">shl</span> <span class="k">i32</span> <span class="nv">%X</span><span class="p">,</span> <span class="m">3</span>
+</pre></div>
+</div>
+<p>And the hard way:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv-Anonymous">%0</span> <span class="p">=</span> <span class="k">add</span> <span class="k">i32</span> <span class="nv">%X</span><span class="p">,</span> <span class="nv">%X</span>           <span class="c">; yields i32:%0</span>
+<span class="nv-Anonymous">%1</span> <span class="p">=</span> <span class="k">add</span> <span class="k">i32</span> <span class="nv-Anonymous">%0</span><span class="p">,</span> <span class="nv-Anonymous">%0</span>           <span class="c">; yields i32:%1</span>
+<span class="nv">%result</span> <span class="p">=</span> <span class="k">add</span> <span class="k">i32</span> <span class="nv-Anonymous">%1</span><span class="p">,</span> <span class="nv-Anonymous">%1</span>
+</pre></div>
+</div>
+<p>This last way of multiplying <tt class="docutils literal"><span class="pre">%X</span></tt> by 8 illustrates several important
+lexical features of LLVM:</p>
+<ol class="arabic simple">
+<li>Comments are delimited with a ‘<tt class="docutils literal"><span class="pre">;</span></tt>‘ and go until the end of line.</li>
+<li>Unnamed temporaries are created when the result of a computation is
+not assigned to a named value.</li>
+<li>Unnamed temporaries are numbered sequentially (using a per-function
+incrementing counter, starting with 0). Note that basic blocks and unnamed
+function parameters are included in this numbering. For example, if the
+entry basic block is not given a label name and all function parameters are
+named, then it will get number 0.</li>
+</ol>
+<p>It also shows a convention that we follow in this document. When
+demonstrating instructions, we will follow an instruction with a comment
+that defines the type and name of value produced.</p>
+</div>
+<div class="section" id="high-level-structure">
+<h2><a class="toc-backref" href="#id583">High Level Structure</a><a class="headerlink" href="#high-level-structure" title="Permalink to this headline">¶</a></h2>
+<div class="section" id="module-structure">
+<h3><a class="toc-backref" href="#id584">Module Structure</a><a class="headerlink" href="#module-structure" title="Permalink to this headline">¶</a></h3>
+<p>LLVM programs are composed of <tt class="docutils literal"><span class="pre">Module</span></tt>‘s, each of which is a
+translation unit of the input programs. Each module consists of
+functions, global variables, and symbol table entries. Modules may be
+combined together with the LLVM linker, which merges function (and
+global variable) definitions, resolves forward declarations, and merges
+symbol table entries. Here is an example of the “hello world” module:</p>
+<div class="highlight-llvm"><div class="highlight"><pre>; Declare the string constant as a global constant.
+ at .str = private unnamed_addr constant [13 x i8] c"hello world\0A\00"
+
+; External declaration of the puts function
+declare i32 @puts(i8* nocapture) nounwind
+
+; Definition of main function
+define i32 @main() {   ; i32()*
+  ; Convert [13 x i8]* to i8  *...
+  %cast210 = getelementptr [13 x i8]* @.str, i64 0, i64 0
+
+  ; Call puts function to write out the string to stdout.
+  call i32 @puts(i8* %cast210)
+  ret i32 0
+}
+
+; Named metadata
+!0 = !{i32 42, null, !"string"}
+!foo = !{!0}
+</pre></div>
+</div>
+<p>This example is made up of a <a class="reference internal" href="#globalvars"><em>global variable</em></a> named
+“<tt class="docutils literal"><span class="pre">.str</span></tt>”, an external declaration of the “<tt class="docutils literal"><span class="pre">puts</span></tt>” function, a
+<a class="reference internal" href="#functionstructure"><em>function definition</em></a> for “<tt class="docutils literal"><span class="pre">main</span></tt>” and
+<a class="reference internal" href="#namedmetadatastructure"><em>named metadata</em></a> “<tt class="docutils literal"><span class="pre">foo</span></tt>”.</p>
+<p>In general, a module is made up of a list of global values (where both
+functions and global variables are global values). Global values are
+represented by a pointer to a memory location (in this case, a pointer
+to an array of char, and a pointer to a function), and have one of the
+following <a class="reference internal" href="#linkage"><em>linkage types</em></a>.</p>
+</div>
+<div class="section" id="linkage-types">
+<span id="linkage"></span><h3><a class="toc-backref" href="#id585">Linkage Types</a><a class="headerlink" href="#linkage-types" title="Permalink to this headline">¶</a></h3>
+<p>All Global Variables and Functions have one of the following types of
+linkage:</p>
+<dl class="docutils">
+<dt><tt class="docutils literal"><span class="pre">private</span></tt></dt>
+<dd>Global values with “<tt class="docutils literal"><span class="pre">private</span></tt>” linkage are only directly
+accessible by objects in the current module. In particular, linking
+code into a module with an private global value may cause the
+private to be renamed as necessary to avoid collisions. Because the
+symbol is private to the module, all references can be updated. This
+doesn’t show up in any symbol table in the object file.</dd>
+<dt><tt class="docutils literal"><span class="pre">internal</span></tt></dt>
+<dd>Similar to private, but the value shows as a local symbol
+(<tt class="docutils literal"><span class="pre">STB_LOCAL</span></tt> in the case of ELF) in the object file. This
+corresponds to the notion of the ‘<tt class="docutils literal"><span class="pre">static</span></tt>‘ keyword in C.</dd>
+<dt><tt class="docutils literal"><span class="pre">available_externally</span></tt></dt>
+<dd>Globals with “<tt class="docutils literal"><span class="pre">available_externally</span></tt>” linkage are never emitted
+into the object file corresponding to the LLVM module. They exist to
+allow inlining and other optimizations to take place given knowledge
+of the definition of the global, which is known to be somewhere
+outside the module. Globals with <tt class="docutils literal"><span class="pre">available_externally</span></tt> linkage
+are allowed to be discarded at will, and are otherwise the same as
+<tt class="docutils literal"><span class="pre">linkonce_odr</span></tt>. This linkage type is only allowed on definitions,
+not declarations.</dd>
+<dt><tt class="docutils literal"><span class="pre">linkonce</span></tt></dt>
+<dd>Globals with “<tt class="docutils literal"><span class="pre">linkonce</span></tt>” linkage are merged with other globals of
+the same name when linkage occurs. This can be used to implement
+some forms of inline functions, templates, or other code which must
+be generated in each translation unit that uses it, but where the
+body may be overridden with a more definitive definition later.
+Unreferenced <tt class="docutils literal"><span class="pre">linkonce</span></tt> globals are allowed to be discarded. Note
+that <tt class="docutils literal"><span class="pre">linkonce</span></tt> linkage does not actually allow the optimizer to
+inline the body of this function into callers because it doesn’t
+know if this definition of the function is the definitive definition
+within the program or whether it will be overridden by a stronger
+definition. To enable inlining and other optimizations, use
+“<tt class="docutils literal"><span class="pre">linkonce_odr</span></tt>” linkage.</dd>
+<dt><tt class="docutils literal"><span class="pre">weak</span></tt></dt>
+<dd>“<tt class="docutils literal"><span class="pre">weak</span></tt>” linkage has the same merging semantics as <tt class="docutils literal"><span class="pre">linkonce</span></tt>
+linkage, except that unreferenced globals with <tt class="docutils literal"><span class="pre">weak</span></tt> linkage may
+not be discarded. This is used for globals that are declared “weak”
+in C source code.</dd>
+<dt><tt class="docutils literal"><span class="pre">common</span></tt></dt>
+<dd>“<tt class="docutils literal"><span class="pre">common</span></tt>” linkage is most similar to “<tt class="docutils literal"><span class="pre">weak</span></tt>” linkage, but they
+are used for tentative definitions in C, such as “<tt class="docutils literal"><span class="pre">int</span> <span class="pre">X;</span></tt>” at
+global scope. Symbols with “<tt class="docutils literal"><span class="pre">common</span></tt>” linkage are merged in the
+same way as <tt class="docutils literal"><span class="pre">weak</span> <span class="pre">symbols</span></tt>, and they may not be deleted if
+unreferenced. <tt class="docutils literal"><span class="pre">common</span></tt> symbols may not have an explicit section,
+must have a zero initializer, and may not be marked
+‘<a class="reference internal" href="#globalvars"><em>constant</em></a>‘. Functions and aliases may not have
+common linkage.</dd>
+</dl>
+<dl class="docutils" id="linkage-appending">
+<dt><tt class="docutils literal"><span class="pre">appending</span></tt></dt>
+<dd>“<tt class="docutils literal"><span class="pre">appending</span></tt>” linkage may only be applied to global variables of
+pointer to array type. When two global variables with appending
+linkage are linked together, the two global arrays are appended
+together. This is the LLVM, typesafe, equivalent of having the
+system linker append together “sections” with identical names when
+.o files are linked.</dd>
+<dt><tt class="docutils literal"><span class="pre">extern_weak</span></tt></dt>
+<dd>The semantics of this linkage follow the ELF object file model: the
+symbol is weak until linked, if not linked, the symbol becomes null
+instead of being an undefined reference.</dd>
+<dt><tt class="docutils literal"><span class="pre">linkonce_odr</span></tt>, <tt class="docutils literal"><span class="pre">weak_odr</span></tt></dt>
+<dd>Some languages allow differing globals to be merged, such as two
+functions with different semantics. Other languages, such as
+<tt class="docutils literal"><span class="pre">C++</span></tt>, ensure that only equivalent globals are ever merged (the
+“one definition rule” — “ODR”).  Such languages can use the
+<tt class="docutils literal"><span class="pre">linkonce_odr</span></tt> and <tt class="docutils literal"><span class="pre">weak_odr</span></tt> linkage types to indicate that the
+global will only be merged with equivalent globals. These linkage
+types are otherwise the same as their non-<tt class="docutils literal"><span class="pre">odr</span></tt> versions.</dd>
+<dt><tt class="docutils literal"><span class="pre">external</span></tt></dt>
+<dd>If none of the above identifiers are used, the global is externally
+visible, meaning that it participates in linkage and can be used to
+resolve external symbol references.</dd>
+</dl>
+<p>It is illegal for a function <em>declaration</em> to have any linkage type
+other than <tt class="docutils literal"><span class="pre">external</span></tt> or <tt class="docutils literal"><span class="pre">extern_weak</span></tt>.</p>
+</div>
+<div class="section" id="calling-conventions">
+<span id="callingconv"></span><h3><a class="toc-backref" href="#id586">Calling Conventions</a><a class="headerlink" href="#calling-conventions" title="Permalink to this headline">¶</a></h3>
+<p>LLVM <a class="reference internal" href="#functionstructure"><em>functions</em></a>, <a class="reference internal" href="#i-call"><em>calls</em></a> and
+<a class="reference internal" href="#i-invoke"><em>invokes</em></a> can all have an optional calling convention
+specified for the call. The calling convention of any pair of dynamic
+caller/callee must match, or the behavior of the program is undefined.
+The following calling conventions are supported by LLVM, and more may be
+added in the future:</p>
+<dl class="docutils">
+<dt>“<tt class="docutils literal"><span class="pre">ccc</span></tt>” - The C calling convention</dt>
+<dd>This calling convention (the default if no other calling convention
+is specified) matches the target C calling conventions. This calling
+convention supports varargs function calls and tolerates some
+mismatch in the declared prototype and implemented declaration of
+the function (as does normal C).</dd>
+<dt>“<tt class="docutils literal"><span class="pre">fastcc</span></tt>” - The fast calling convention</dt>
+<dd>This calling convention attempts to make calls as fast as possible
+(e.g. by passing things in registers). This calling convention
+allows the target to use whatever tricks it wants to produce fast
+code for the target, without having to conform to an externally
+specified ABI (Application Binary Interface). <a class="reference external" href="CodeGenerator.html#id80">Tail calls can only
+be optimized when this, the GHC or the HiPE convention is
+used.</a> This calling convention does not
+support varargs and requires the prototype of all callees to exactly
+match the prototype of the function definition.</dd>
+<dt>“<tt class="docutils literal"><span class="pre">coldcc</span></tt>” - The cold calling convention</dt>
+<dd>This calling convention attempts to make code in the caller as
+efficient as possible under the assumption that the call is not
+commonly executed. As such, these calls often preserve all registers
+so that the call does not break any live ranges in the caller side.
+This calling convention does not support varargs and requires the
+prototype of all callees to exactly match the prototype of the
+function definition. Furthermore the inliner doesn’t consider such function
+calls for inlining.</dd>
+<dt>“<tt class="docutils literal"><span class="pre">cc</span> <span class="pre">10</span></tt>” - GHC convention</dt>
+<dd><p class="first">This calling convention has been implemented specifically for use by
+the <a class="reference external" href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
+It passes everything in registers, going to extremes to achieve this
+by disabling callee save registers. This calling convention should
+not be used lightly but only for specific situations such as an
+alternative to the <em>register pinning</em> performance technique often
+used when implementing functional programming languages. At the
+moment only X86 supports this convention and it has the following
+limitations:</p>
+<ul class="simple">
+<li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
+floating point types are supported.</li>
+<li>On <em>X86-64</em> only supports up to 10 bit type parameters and 6
+floating point parameters.</li>
+</ul>
+<p class="last">This calling convention supports <a class="reference external" href="CodeGenerator.html#id80">tail call
+optimization</a> but requires both the
+caller and callee are using it.</p>
+</dd>
+<dt>“<tt class="docutils literal"><span class="pre">cc</span> <span class="pre">11</span></tt>” - The HiPE calling convention</dt>
+<dd>This calling convention has been implemented specifically for use by
+the <a class="reference external" href="http://www.it.uu.se/research/group/hipe/">High-Performance Erlang
+(HiPE)</a> compiler, <em>the</em>
+native code compiler of the <a class="reference external" href="http://www.erlang.org/download.shtml">Ericsson’s Open Source Erlang/OTP
+system</a>. It uses more
+registers for argument passing than the ordinary C calling
+convention and defines no callee-saved registers. The calling
+convention properly supports <a class="reference external" href="CodeGenerator.html#id80">tail call
+optimization</a> but requires that both the
+caller and the callee use it. It uses a <em>register pinning</em>
+mechanism, similar to GHC’s convention, for keeping frequently
+accessed runtime components pinned to specific hardware registers.
+At the moment only X86 supports this convention (both 32 and 64
+bit).</dd>
+<dt>“<tt class="docutils literal"><span class="pre">webkit_jscc</span></tt>” - WebKit’s JavaScript calling convention</dt>
+<dd>This calling convention has been implemented for <a class="reference external" href="https://trac.webkit.org/wiki/FTLJIT">WebKit FTL JIT</a>. It passes arguments on the
+stack right to left (as cdecl does), and returns a value in the
+platform’s customary return register.</dd>
+<dt>“<tt class="docutils literal"><span class="pre">anyregcc</span></tt>” - Dynamic calling convention for code patching</dt>
+<dd>This is a special convention that supports patching an arbitrary code
+sequence in place of a call site. This convention forces the call
+arguments into registers but allows them to be dynamcially
+allocated. This can currently only be used with calls to
+llvm.experimental.patchpoint because only this intrinsic records
+the location of its arguments in a side table. See <a class="reference internal" href="StackMaps.html"><em>Stack maps and patch points in LLVM</em></a>.</dd>
+<dt>“<tt class="docutils literal"><span class="pre">preserve_mostcc</span></tt>” - The <cite>PreserveMost</cite> calling convention</dt>
+<dd><p class="first">This calling convention attempts to make the code in the caller as little
+intrusive as possible. This calling convention behaves identical to the <cite>C</cite>
+calling convention on how arguments and return values are passed, but it
+uses a different set of caller/callee-saved registers. This alleviates the
+burden of saving and recovering a large register set before and after the
+call in the caller. If the arguments are passed in callee-saved registers,
+then they will be preserved by the callee across the call. This doesn’t
+apply for values returned in callee-saved registers.</p>
+<ul class="simple">
+<li>On X86-64 the callee preserves all general purpose registers, except for
+R11. R11 can be used as a scratch register. Floating-point registers
+(XMMs/YMMs) are not preserved and need to be saved by the caller.</li>
+</ul>
+<p>The idea behind this convention is to support calls to runtime functions
+that have a hot path and a cold path. The hot path is usually a small piece
+of code that doesn’t many registers. The cold path might need to call out to
+another function and therefore only needs to preserve the caller-saved
+registers, which haven’t already been saved by the caller. The
+<cite>PreserveMost</cite> calling convention is very similar to the <cite>cold</cite> calling
+convention in terms of caller/callee-saved registers, but they are used for
+different types of function calls. <cite>coldcc</cite> is for function calls that are
+rarely executed, whereas <cite>preserve_mostcc</cite> function calls are intended to be
+on the hot path and definitely executed a lot. Furthermore <cite>preserve_mostcc</cite>
+doesn’t prevent the inliner from inlining the function call.</p>
+<p class="last">This calling convention will be used by a future version of the ObjectiveC
+runtime and should therefore still be considered experimental at this time.
+Although this convention was created to optimize certain runtime calls to
+the ObjectiveC runtime, it is not limited to this runtime and might be used
+by other runtimes in the future too. The current implementation only
+supports X86-64, but the intention is to support more architectures in the
+future.</p>
+</dd>
+<dt>“<tt class="docutils literal"><span class="pre">preserve_allcc</span></tt>” - The <cite>PreserveAll</cite> calling convention</dt>
+<dd><p class="first">This calling convention attempts to make the code in the caller even less
+intrusive than the <cite>PreserveMost</cite> calling convention. This calling
+convention also behaves identical to the <cite>C</cite> calling convention on how
+arguments and return values are passed, but it uses a different set of
+caller/callee-saved registers. This removes the burden of saving and
+recovering a large register set before and after the call in the caller. If
+the arguments are passed in callee-saved registers, then they will be
+preserved by the callee across the call. This doesn’t apply for values
+returned in callee-saved registers.</p>
+<ul class="simple">
+<li>On X86-64 the callee preserves all general purpose registers, except for
+R11. R11 can be used as a scratch register. Furthermore it also preserves
+all floating-point registers (XMMs/YMMs).</li>
+</ul>
+<p>The idea behind this convention is to support calls to runtime functions
+that don’t need to call out to any other functions.</p>
+<p class="last">This calling convention, like the <cite>PreserveMost</cite> calling convention, will be
+used by a future version of the ObjectiveC runtime and should be considered
+experimental at this time.</p>
+</dd>
+<dt>“<tt class="docutils literal"><span class="pre">cc</span> <span class="pre"><n></span></tt>” - Numbered convention</dt>
+<dd>Any calling convention may be specified by number, allowing
+target-specific calling conventions to be used. Target specific
+calling conventions start at 64.</dd>
+</dl>
+<p>More calling conventions can be added/defined on an as-needed basis, to
+support Pascal conventions or any other well-known target-independent
+convention.</p>
+</div>
+<div class="section" id="visibility-styles">
+<span id="visibilitystyles"></span><h3><a class="toc-backref" href="#id587">Visibility Styles</a><a class="headerlink" href="#visibility-styles" title="Permalink to this headline">¶</a></h3>
+<p>All Global Variables and Functions have one of the following visibility
+styles:</p>
+<dl class="docutils">
+<dt>“<tt class="docutils literal"><span class="pre">default</span></tt>” - Default style</dt>
+<dd>On targets that use the ELF object file format, default visibility
+means that the declaration is visible to other modules and, in
+shared libraries, means that the declared entity may be overridden.
+On Darwin, default visibility means that the declaration is visible
+to other modules. Default visibility corresponds to “external
+linkage” in the language.</dd>
+<dt>“<tt class="docutils literal"><span class="pre">hidden</span></tt>” - Hidden style</dt>
+<dd>Two declarations of an object with hidden visibility refer to the
+same object if they are in the same shared object. Usually, hidden
+visibility indicates that the symbol will not be placed into the
+dynamic symbol table, so no other module (executable or shared
+library) can reference it directly.</dd>
+<dt>“<tt class="docutils literal"><span class="pre">protected</span></tt>” - Protected style</dt>
+<dd>On ELF, protected visibility indicates that the symbol will be
+placed in the dynamic symbol table, but that references within the
+defining module will bind to the local symbol. That is, the symbol
+cannot be overridden by another module.</dd>
+</dl>
+<p>A symbol with <tt class="docutils literal"><span class="pre">internal</span></tt> or <tt class="docutils literal"><span class="pre">private</span></tt> linkage must have <tt class="docutils literal"><span class="pre">default</span></tt>
+visibility.</p>
+</div>
+<div class="section" id="dll-storage-classes">
+<span id="dllstorageclass"></span><h3><a class="toc-backref" href="#id588">DLL Storage Classes</a><a class="headerlink" href="#dll-storage-classes" title="Permalink to this headline">¶</a></h3>
+<p>All Global Variables, Functions and Aliases can have one of the following
+DLL storage class:</p>
+<dl class="docutils">
+<dt><tt class="docutils literal"><span class="pre">dllimport</span></tt></dt>
+<dd>“<tt class="docutils literal"><span class="pre">dllimport</span></tt>” causes the compiler to reference a function or variable via
+a global pointer to a pointer that is set up by the DLL exporting the
+symbol. On Microsoft Windows targets, the pointer name is formed by
+combining <tt class="docutils literal"><span class="pre">__imp_</span></tt> and the function or variable name.</dd>
+<dt><tt class="docutils literal"><span class="pre">dllexport</span></tt></dt>
+<dd>“<tt class="docutils literal"><span class="pre">dllexport</span></tt>” causes the compiler to provide a global pointer to a pointer
+in a DLL, so that it can be referenced with the <tt class="docutils literal"><span class="pre">dllimport</span></tt> attribute. On
+Microsoft Windows targets, the pointer name is formed by combining
+<tt class="docutils literal"><span class="pre">__imp_</span></tt> and the function or variable name. Since this storage class
+exists for defining a dll interface, the compiler, assembler and linker know
+it is externally referenced and must refrain from deleting the symbol.</dd>
+</dl>
+</div>
+<div class="section" id="thread-local-storage-models">
+<span id="tls-model"></span><h3><a class="toc-backref" href="#id589">Thread Local Storage Models</a><a class="headerlink" href="#thread-local-storage-models" title="Permalink to this headline">¶</a></h3>
+<p>A variable may be defined as <tt class="docutils literal"><span class="pre">thread_local</span></tt>, which means that it will
+not be shared by threads (each thread will have a separated copy of the
+variable). Not all targets support thread-local variables. Optionally, a
+TLS model may be specified:</p>
+<dl class="docutils">
+<dt><tt class="docutils literal"><span class="pre">localdynamic</span></tt></dt>
+<dd>For variables that are only used within the current shared library.</dd>
+<dt><tt class="docutils literal"><span class="pre">initialexec</span></tt></dt>
+<dd>For variables in modules that will not be loaded dynamically.</dd>
+<dt><tt class="docutils literal"><span class="pre">localexec</span></tt></dt>
+<dd>For variables defined in the executable and only used within it.</dd>
+</dl>
+<p>If no explicit model is given, the “general dynamic” model is used.</p>
+<p>The models correspond to the ELF TLS models; see <a class="reference external" href="http://people.redhat.com/drepper/tls.pdf">ELF Handling For
+Thread-Local Storage</a> for
+more information on under which circumstances the different models may
+be used. The target may choose a different TLS model if the specified
+model is not supported, or if a better choice of model can be made.</p>
+<p>A model can also be specified in a alias, but then it only governs how
+the alias is accessed. It will not have any effect in the aliasee.</p>
+</div>
+<div class="section" id="structure-types">
+<span id="namedtypes"></span><h3><a class="toc-backref" href="#id590">Structure Types</a><a class="headerlink" href="#structure-types" title="Permalink to this headline">¶</a></h3>
+<p>LLVM IR allows you to specify both “identified” and “literal” <a class="reference internal" href="#t-struct"><em>structure
+types</em></a>.  Literal types are uniqued structurally, but identified types
+are never uniqued.  An <a class="reference internal" href="#t-opaque"><em>opaque structural type</em></a> can also be used
+to forward declare a type that is not yet available.</p>
+<p>An example of a identified structure specification is:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%mytype</span> <span class="p">=</span> <span class="k">type</span> <span class="p">{</span> <span class="nv">%mytype</span><span class="p">*,</span> <span class="k">i32</span> <span class="p">}</span>
+</pre></div>
+</div>
+<p>Prior to the LLVM 3.0 release, identified types were structurally uniqued.  Only
+literal types are uniqued in recent versions of LLVM.</p>
+</div>
+<div class="section" id="global-variables">
+<span id="globalvars"></span><h3><a class="toc-backref" href="#id591">Global Variables</a><a class="headerlink" href="#global-variables" title="Permalink to this headline">¶</a></h3>
+<p>Global variables define regions of memory allocated at compilation time
+instead of run-time.</p>
+<p>Global variables definitions must be initialized.</p>
+<p>Global variables in other translation units can also be declared, in which
+case they don’t have an initializer.</p>
+<p>Either global variable definitions or declarations may have an explicit section
+to be placed in and may have an optional explicit alignment specified.</p>
+<p>A variable may be defined as a global <tt class="docutils literal"><span class="pre">constant</span></tt>, which indicates that
+the contents of the variable will <strong>never</strong> be modified (enabling better
+optimization, allowing the global data to be placed in the read-only
+section of an executable, etc). Note that variables that need runtime
+initialization cannot be marked <tt class="docutils literal"><span class="pre">constant</span></tt> as there is a store to the
+variable.</p>
+<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
+constant, even if the final definition of the global is not. This
+capability can be used to enable slightly better optimization of the
+program, but requires the language definition to guarantee that
+optimizations based on the ‘constantness’ are valid for the translation
+units that do not include the definition.</p>
+<p>As SSA values, global variables define pointer values that are in scope
+(i.e. they dominate) all basic blocks in the program. Global variables
+always define a pointer to their “content” type because they describe a
+region of memory, and all memory objects in LLVM are accessed through
+pointers.</p>
+<p>Global variables can be marked with <tt class="docutils literal"><span class="pre">unnamed_addr</span></tt> which indicates
+that the address is not significant, only the content. Constants marked
+like this can be merged with other constants if they have the same
+initializer. Note that a constant with significant address <em>can</em> be
+merged with a <tt class="docutils literal"><span class="pre">unnamed_addr</span></tt> constant, the result being a constant
+whose address is significant.</p>
+<p>A global variable may be declared to reside in a target-specific
+numbered address space. For targets that support them, address spaces
+may affect how optimizations are performed and/or what target
+instructions are used to access the variable. The default address space
+is zero. The address space qualifier must precede any other attributes.</p>
+<p>LLVM allows an explicit section to be specified for globals. If the
+target supports it, it will emit globals to the section specified.
+Additionally, the global can placed in a comdat if the target has the necessary
+support.</p>
+<p>By default, global initializers are optimized by assuming that global
+variables defined within the module are not modified from their
+initial values before the start of the global initializer.  This is
+true even for variables potentially accessible from outside the
+module, including those with external linkage or appearing in
+<tt class="docutils literal"><span class="pre">@llvm.used</span></tt> or dllexported variables. This assumption may be suppressed
+by marking the variable with <tt class="docutils literal"><span class="pre">externally_initialized</span></tt>.</p>
+<p>An explicit alignment may be specified for a global, which must be a
+power of 2. If not present, or if the alignment is set to zero, the
+alignment of the global is set by the target to whatever it feels
+convenient. If an explicit alignment is specified, the global is forced
+to have exactly that alignment. Targets and optimizers are not allowed
+to over-align the global if the global has an assigned section. In this
+case, the extra alignment could be observable: for example, code could
+assume that the globals are densely packed in their section and try to
+iterate over them as an array, alignment padding would break this
+iteration. The maximum alignment is <tt class="docutils literal"><span class="pre">1</span> <span class="pre"><<</span> <span class="pre">29</span></tt>.</p>
+<p>Globals can also have a <a class="reference internal" href="#dllstorageclass"><em>DLL storage class</em></a>.</p>
+<p>Variables and aliasaes can have a
+<a class="reference internal" href="#tls-model"><em>Thread Local Storage Model</em></a>.</p>
+<p>Syntax:</p>
+<div class="highlight-python"><div class="highlight"><pre>[@<GlobalVarName> =] [Linkage] [Visibility] [DLLStorageClass] [ThreadLocal]
+                     [unnamed_addr] [AddrSpace] [ExternallyInitialized]
+                     <global | constant> <Type> [<InitializerConstant>]
+                     [, section "name"] [, comdat [($name)]]
+                     [, align <Alignment>]
+</pre></div>
+</div>
+<p>For example, the following defines a global in a numbered address space
+with an initializer, section, and alignment:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="vg">@G</span> <span class="p">=</span> <span class="k">addrspace</span><span class="p">(</span><span class="m">5</span><span class="p">)</span> <span class="k">constant</span> <span class="kt">float</span> <span class="m">1.0</span><span class="p">,</span> <span class="k">section</span> <span class="s">"foo"</span><span class="p">,</span> <span class="k">align</span> <span class="m">4</span>
+</pre></div>
+</div>
+<p>The following example just declares a global variable</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="vg">@G</span> <span class="p">=</span> <span class="k">external</span> <span class="k">global</span> <span class="k">i32</span>
+</pre></div>
+</div>
+<p>The following example defines a thread-local global with the
+<tt class="docutils literal"><span class="pre">initialexec</span></tt> TLS model:</p>
+<div class="highlight-llvm"><div class="highlight"><pre>@G = thread_local(initialexec) global i32 0, align 4
+</pre></div>
+</div>
+</div>
+<div class="section" id="functions">
+<span id="functionstructure"></span><h3><a class="toc-backref" href="#id592">Functions</a><a class="headerlink" href="#functions" title="Permalink to this headline">¶</a></h3>
+<p>LLVM function definitions consist of the “<tt class="docutils literal"><span class="pre">define</span></tt>” keyword, an
+optional <a class="reference internal" href="#linkage"><em>linkage type</em></a>, an optional <a class="reference internal" href="BitCodeFormat.html#visibility"><em>visibility
+style</em></a>, an optional <a class="reference internal" href="#dllstorageclass"><em>DLL storage class</em></a>,
+an optional <a class="reference internal" href="#callingconv"><em>calling convention</em></a>,
+an optional <tt class="docutils literal"><span class="pre">unnamed_addr</span></tt> attribute, a return type, an optional
+<a class="reference internal" href="#paramattrs"><em>parameter attribute</em></a> for the return type, a function
+name, a (possibly empty) argument list (each with optional <a class="reference internal" href="#paramattrs"><em>parameter
+attributes</em></a>), optional <a class="reference internal" href="#fnattrs"><em>function attributes</em></a>,
+an optional section, an optional alignment,
+an optional <a class="reference internal" href="#langref-comdats"><em>comdat</em></a>,
+an optional <a class="reference internal" href="#gc"><em>garbage collector name</em></a>, an optional <a class="reference internal" href="#prefixdata"><em>prefix</em></a>,
+an optional <a class="reference internal" href="#prologuedata"><em>prologue</em></a>, an opening
+curly brace, a list of basic blocks, and a closing curly brace.</p>
+<p>LLVM function declarations consist of the “<tt class="docutils literal"><span class="pre">declare</span></tt>” keyword, an
+optional <a class="reference internal" href="#linkage"><em>linkage type</em></a>, an optional <a class="reference internal" href="BitCodeFormat.html#visibility"><em>visibility
+style</em></a>, an optional <a class="reference internal" href="#dllstorageclass"><em>DLL storage class</em></a>,
+an optional <a class="reference internal" href="#callingconv"><em>calling convention</em></a>,
+an optional <tt class="docutils literal"><span class="pre">unnamed_addr</span></tt> attribute, a return type, an optional
+<a class="reference internal" href="#paramattrs"><em>parameter attribute</em></a> for the return type, a function
+name, a possibly empty list of arguments, an optional alignment, an optional
+<a class="reference internal" href="#gc"><em>garbage collector name</em></a>, an optional <a class="reference internal" href="#prefixdata"><em>prefix</em></a>,
+and an optional <a class="reference internal" href="#prologuedata"><em>prologue</em></a>.</p>
+<p>A function definition contains a list of basic blocks, forming the CFG (Control
+Flow Graph) for the function. Each basic block may optionally start with a label
+(giving the basic block a symbol table entry), contains a list of instructions,
+and ends with a <a class="reference internal" href="#terminators"><em>terminator</em></a> instruction (such as a branch or
+function return). If an explicit label is not provided, a block is assigned an
+implicit numbered label, using the next value from the same counter as used for
+unnamed temporaries (<a class="reference internal" href="#identifiers"><em>see above</em></a>). For example, if a function
+entry block does not have an explicit label, it will be assigned label “%0”,
+then the first unnamed temporary in that block will be “%1”, etc.</p>
+<p>The first basic block in a function is special in two ways: it is
+immediately executed on entrance to the function, and it is not allowed
+to have predecessor basic blocks (i.e. there can not be any branches to
+the entry block of a function). Because the block can have no
+predecessors, it also cannot have any <a class="reference internal" href="#i-phi"><em>PHI nodes</em></a>.</p>
+<p>LLVM allows an explicit section to be specified for functions. If the
+target supports it, it will emit functions to the section specified.
+Additionally, the function can placed in a COMDAT.</p>
+<p>An explicit alignment may be specified for a function. If not present,
+or if the alignment is set to zero, the alignment of the function is set
+by the target to whatever it feels convenient. If an explicit alignment
+is specified, the function is forced to have at least that much
+alignment. All alignments must be a power of 2.</p>
+<p>If the <tt class="docutils literal"><span class="pre">unnamed_addr</span></tt> attribute is given, the address is know to not
+be significant and two identical functions can be merged.</p>
+<p>Syntax:</p>
+<div class="highlight-python"><div class="highlight"><pre>define [linkage] [visibility] [DLLStorageClass]
+       [cconv] [ret attrs]
+       <ResultType> @<FunctionName> ([argument list])
+       [unnamed_addr] [fn Attrs] [section "name"] [comdat [($name)]]
+       [align N] [gc] [prefix Constant] [prologue Constant] { ... }
+</pre></div>
+</div>
+<p>The argument list is a comma seperated sequence of arguments where each
+argument is of the following form</p>
+<p>Syntax:</p>
+<div class="highlight-python"><div class="highlight"><pre><type> [parameter Attrs] [name]
+</pre></div>
+</div>
+</div>
+<div class="section" id="aliases">
+<span id="langref-aliases"></span><h3><a class="toc-backref" href="#id593">Aliases</a><a class="headerlink" href="#aliases" title="Permalink to this headline">¶</a></h3>
+<p>Aliases, unlike function or variables, don’t create any new data. They
+are just a new symbol and metadata for an existing position.</p>
+<p>Aliases have a name and an aliasee that is either a global value or a
+constant expression.</p>
+<p>Aliases may have an optional <a class="reference internal" href="#linkage"><em>linkage type</em></a>, an optional
+<a class="reference internal" href="BitCodeFormat.html#visibility"><em>visibility style</em></a>, an optional <a class="reference internal" href="#dllstorageclass"><em>DLL storage class</em></a> and an optional <a class="reference internal" href="#tls-model"><em>tls model</em></a>.</p>
+<p>Syntax:</p>
+<div class="highlight-python"><div class="highlight"><pre>@<Name> = [Linkage] [Visibility] [DLLStorageClass] [ThreadLocal] [unnamed_addr] alias <AliaseeTy> @<Aliasee>
+</pre></div>
+</div>
+<p>The linkage must be one of <tt class="docutils literal"><span class="pre">private</span></tt>, <tt class="docutils literal"><span class="pre">internal</span></tt>, <tt class="docutils literal"><span class="pre">linkonce</span></tt>, <tt class="docutils literal"><span class="pre">weak</span></tt>,
+<tt class="docutils literal"><span class="pre">linkonce_odr</span></tt>, <tt class="docutils literal"><span class="pre">weak_odr</span></tt>, <tt class="docutils literal"><span class="pre">external</span></tt>. Note that some system linkers
+might not correctly handle dropping a weak symbol that is aliased.</p>
+<p>Alias that are not <tt class="docutils literal"><span class="pre">unnamed_addr</span></tt> are guaranteed to have the same address as
+the aliasee expression. <tt class="docutils literal"><span class="pre">unnamed_addr</span></tt> ones are only guaranteed to point
+to the same content.</p>
+<p>Since aliases are only a second name, some restrictions apply, of which
+some can only be checked when producing an object file:</p>
+<ul class="simple">
+<li>The expression defining the aliasee must be computable at assembly
+time. Since it is just a name, no relocations can be used.</li>
+<li>No alias in the expression can be weak as the possibility of the
+intermediate alias being overridden cannot be represented in an
+object file.</li>
+<li>No global value in the expression can be a declaration, since that
+would require a relocation, which is not possible.</li>
+</ul>
+</div>
+<div class="section" id="comdats">
+<span id="langref-comdats"></span><h3><a class="toc-backref" href="#id594">Comdats</a><a class="headerlink" href="#comdats" title="Permalink to this headline">¶</a></h3>
+<p>Comdat IR provides access to COFF and ELF object file COMDAT functionality.</p>
+<p>Comdats have a name which represents the COMDAT key.  All global objects that
+specify this key will only end up in the final object file if the linker chooses
+that key over some other key.  Aliases are placed in the same COMDAT that their
+aliasee computes to, if any.</p>
+<p>Comdats have a selection kind to provide input on how the linker should
+choose between keys in two different object files.</p>
+<p>Syntax:</p>
+<div class="highlight-python"><div class="highlight"><pre>$<Name> = comdat SelectionKind
+</pre></div>
+</div>
+<p>The selection kind must be one of the following:</p>
+<dl class="docutils">
+<dt><tt class="docutils literal"><span class="pre">any</span></tt></dt>
+<dd>The linker may choose any COMDAT key, the choice is arbitrary.</dd>
+<dt><tt class="docutils literal"><span class="pre">exactmatch</span></tt></dt>
+<dd>The linker may choose any COMDAT key but the sections must contain the
+same data.</dd>
+<dt><tt class="docutils literal"><span class="pre">largest</span></tt></dt>
+<dd>The linker will choose the section containing the largest COMDAT key.</dd>
+<dt><tt class="docutils literal"><span class="pre">noduplicates</span></tt></dt>
+<dd>The linker requires that only section with this COMDAT key exist.</dd>
+<dt><tt class="docutils literal"><span class="pre">samesize</span></tt></dt>
+<dd>The linker may choose any COMDAT key but the sections must contain the
+same amount of data.</dd>
+</dl>
+<p>Note that the Mach-O platform doesn’t support COMDATs and ELF only supports
+<tt class="docutils literal"><span class="pre">any</span></tt> as a selection kind.</p>
+<p>Here is an example of a COMDAT group where a function will only be selected if
+the COMDAT key’s section is the largest:</p>
+<div class="highlight-llvm"><div class="highlight"><pre>$foo = comdat largest
+ at foo = global i32 2, comdat($foo)
+
+define void @bar() comdat($foo) {
+  ret void
+}
+</pre></div>
+</div>
+<p>As a syntactic sugar the <tt class="docutils literal"><span class="pre">$name</span></tt> can be omitted if the name is the same as
+the global name:</p>
+<div class="highlight-llvm"><div class="highlight"><pre>$foo = comdat any
+ at foo = global i32 2, comdat
+</pre></div>
+</div>
+<p>In a COFF object file, this will create a COMDAT section with selection kind
+<tt class="docutils literal"><span class="pre">IMAGE_COMDAT_SELECT_LARGEST</span></tt> containing the contents of the <tt class="docutils literal"><span class="pre">@foo</span></tt> symbol
+and another COMDAT section with selection kind
+<tt class="docutils literal"><span class="pre">IMAGE_COMDAT_SELECT_ASSOCIATIVE</span></tt> which is associated with the first COMDAT
+section and contains the contents of the <tt class="docutils literal"><span class="pre">@bar</span></tt> symbol.</p>
+<p>There are some restrictions on the properties of the global object.
+It, or an alias to it, must have the same name as the COMDAT group when
+targeting COFF.
+The contents and size of this object may be used during link-time to determine
+which COMDAT groups get selected depending on the selection kind.
+Because the name of the object must match the name of the COMDAT group, the
+linkage of the global object must not be local; local symbols can get renamed
+if a collision occurs in the symbol table.</p>
+<p>The combined use of COMDATS and section attributes may yield surprising results.
+For example:</p>
+<div class="highlight-llvm"><div class="highlight"><pre>$foo = comdat any
+$bar = comdat any
+ at g1 = global i32 42, section "sec", comdat($foo)
+ at g2 = global i32 42, section "sec", comdat($bar)
+</pre></div>
+</div>
+<p>From the object file perspective, this requires the creation of two sections
+with the same name.  This is necessary because both globals belong to different
+COMDAT groups and COMDATs, at the object file level, are represented by
+sections.</p>
+<p>Note that certain IR constructs like global variables and functions may create
+COMDATs in the object file in addition to any which are specified using COMDAT
+IR.  This arises, for example, when a global variable has linkonce_odr linkage.</p>
+</div>
+<div class="section" id="named-metadata">
+<span id="namedmetadatastructure"></span><h3><a class="toc-backref" href="#id595">Named Metadata</a><a class="headerlink" href="#named-metadata" title="Permalink to this headline">¶</a></h3>
+<p>Named metadata is a collection of metadata. <a class="reference internal" href="#metadata"><em>Metadata
+nodes</em></a> (but not metadata strings) are the only valid
+operands for a named metadata.</p>
+<p>Syntax:</p>
+<div class="highlight-python"><div class="highlight"><pre>; Some unnamed metadata nodes, which are referenced by the named metadata.
+!0 = !{!"zero"}
+!1 = !{!"one"}
+!2 = !{!"two"}
+; A named metadata.
+!name = !{!0, !1, !2}
+</pre></div>
+</div>
+</div>
+<div class="section" id="parameter-attributes">
+<span id="paramattrs"></span><h3><a class="toc-backref" href="#id596">Parameter Attributes</a><a class="headerlink" href="#parameter-attributes" title="Permalink to this headline">¶</a></h3>
+<p>The return type and each parameter of a function type may have a set of
+<em>parameter attributes</em> associated with them. Parameter attributes are
+used to communicate additional information about the result or
+parameters of a function. Parameter attributes are considered to be part
+of the function, not of the function type, so functions with different
+parameter attributes can have the same function type.</p>
+<p>Parameter attributes are simple keywords that follow the type specified.
+If multiple parameter attributes are needed, they are space separated.
+For example:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="k">declare</span> <span class="k">i32</span> <span class="vg">@printf</span><span class="p">(</span><span class="k">i8</span><span class="p">*</span> <span class="k">noalias</span> <span class="k">nocapture</span><span class="p">,</span> <span class="p">...)</span>
+<span class="k">declare</span> <span class="k">i32</span> <span class="vg">@atoi</span><span class="p">(</span><span class="k">i8</span> <span class="k">zeroext</span><span class="p">)</span>
+<span class="k">declare</span> <span class="k">signext</span> <span class="k">i8</span> <span class="vg">@returns_signed_char</span><span class="p">()</span>
+</pre></div>
+</div>
+<p>Note that any attributes for the function result (<tt class="docutils literal"><span class="pre">nounwind</span></tt>,
+<tt class="docutils literal"><span class="pre">readonly</span></tt>) come immediately after the argument list.</p>
+<p>Currently, only the following parameter attributes are defined:</p>
+<dl class="docutils">
+<dt><tt class="docutils literal"><span class="pre">zeroext</span></tt></dt>
+<dd>This indicates to the code generator that the parameter or return
+value should be zero-extended to the extent required by the target’s
+ABI (which is usually 32-bits, but is 8-bits for a i1 on x86-64) by
+the caller (for a parameter) or the callee (for a return value).</dd>
+<dt><tt class="docutils literal"><span class="pre">signext</span></tt></dt>
+<dd>This indicates to the code generator that the parameter or return
+value should be sign-extended to the extent required by the target’s
+ABI (which is usually 32-bits) by the caller (for a parameter) or
+the callee (for a return value).</dd>
+<dt><tt class="docutils literal"><span class="pre">inreg</span></tt></dt>
+<dd>This indicates that this parameter or return value should be treated
+in a special target-dependent fashion during while emitting code for
+a function call or return (usually, by putting it in a register as
+opposed to memory, though some targets use it to distinguish between
+two different kinds of registers). Use of this attribute is
+target-specific.</dd>
+<dt><tt class="docutils literal"><span class="pre">byval</span></tt></dt>
+<dd><p class="first">This indicates that the pointer parameter should really be passed by
+value to the function. The attribute implies that a hidden copy of
+the pointee is made between the caller and the callee, so the callee
+is unable to modify the value in the caller. This attribute is only
+valid on LLVM pointer arguments. It is generally used to pass
+structs and arrays by value, but is also valid on pointers to
+scalars. The copy is considered to belong to the caller not the
+callee (for example, <tt class="docutils literal"><span class="pre">readonly</span></tt> functions should not write to
+<tt class="docutils literal"><span class="pre">byval</span></tt> parameters). This is not a valid attribute for return
+values.</p>
+<p class="last">The byval attribute also supports specifying an alignment with the
+align attribute. It indicates the alignment of the stack slot to
+form and the known alignment of the pointer specified to the call
+site. If the alignment is not specified, then the code generator
+makes a target-specific assumption.</p>
+</dd>
+</dl>
+<p id="attr-inalloca"><tt class="docutils literal"><span class="pre">inalloca</span></tt></p>
+<blockquote>
+<div><p>The <tt class="docutils literal"><span class="pre">inalloca</span></tt> argument attribute allows the caller to take the
+address of outgoing stack arguments.  An <tt class="docutils literal"><span class="pre">inalloca</span></tt> argument must
+be a pointer to stack memory produced by an <tt class="docutils literal"><span class="pre">alloca</span></tt> instruction.
+The alloca, or argument allocation, must also be tagged with the
+inalloca keyword.  Only the last argument may have the <tt class="docutils literal"><span class="pre">inalloca</span></tt>
+attribute, and that argument is guaranteed to be passed in memory.</p>
+<p>An argument allocation may be used by a call at most once because
+the call may deallocate it.  The <tt class="docutils literal"><span class="pre">inalloca</span></tt> attribute cannot be
+used in conjunction with other attributes that affect argument
+storage, like <tt class="docutils literal"><span class="pre">inreg</span></tt>, <tt class="docutils literal"><span class="pre">nest</span></tt>, <tt class="docutils literal"><span class="pre">sret</span></tt>, or <tt class="docutils literal"><span class="pre">byval</span></tt>.  The
+<tt class="docutils literal"><span class="pre">inalloca</span></tt> attribute also disables LLVM’s implicit lowering of
+large aggregate return values, which means that frontend authors
+must lower them with <tt class="docutils literal"><span class="pre">sret</span></tt> pointers.</p>
+<p>When the call site is reached, the argument allocation must have
+been the most recent stack allocation that is still live, or the
+results are undefined.  It is possible to allocate additional stack
+space after an argument allocation and before its call site, but it
+must be cleared off with <a class="reference internal" href="#int-stackrestore"><em>llvm.stackrestore</em></a>.</p>
+<p>See <a class="reference internal" href="InAlloca.html"><em>Design and Usage of the InAlloca Attribute</em></a> for more information on how to use this
+attribute.</p>
+</div></blockquote>
+<dl class="docutils">
+<dt><tt class="docutils literal"><span class="pre">sret</span></tt></dt>
+<dd>This indicates that the pointer parameter specifies the address of a
+structure that is the return value of the function in the source
+program. This pointer must be guaranteed by the caller to be valid:
+loads and stores to the structure may be assumed by the callee
+not to trap and to be properly aligned. This may only be applied to
+the first parameter. This is not a valid attribute for return
+values.</dd>
+<dt><tt class="docutils literal"><span class="pre">align</span> <span class="pre"><n></span></tt></dt>
+<dd><p class="first">This indicates that the pointer value may be assumed by the optimizer to
+have the specified alignment.</p>
+<p class="last">Note that this attribute has additional semantics when combined with the
+<tt class="docutils literal"><span class="pre">byval</span></tt> attribute.</p>
+</dd>
+</dl>
+<dl class="docutils" id="noalias">
+<dt><tt class="docutils literal"><span class="pre">noalias</span></tt></dt>
+<dd><p class="first">This indicates that objects accessed via pointer values
+<a class="reference internal" href="#pointeraliasing"><em>based</em></a> on the argument or return value are not also
+accessed, during the execution of the function, via pointer values not
+<em>based</em> on the argument or return value. The attribute on a return value
+also has additional semantics described below. The caller shares the
+responsibility with the callee for ensuring that these requirements are met.
+For further details, please see the discussion of the NoAlias response in
+<a class="reference internal" href="AliasAnalysis.html#must-may-or-no"><em>alias analysis</em></a>.</p>
+<p>Note that this definition of <tt class="docutils literal"><span class="pre">noalias</span></tt> is intentionally similar
+to the definition of <tt class="docutils literal"><span class="pre">restrict</span></tt> in C99 for function arguments.</p>
+<p class="last">For function return values, C99’s <tt class="docutils literal"><span class="pre">restrict</span></tt> is not meaningful,
+while LLVM’s <tt class="docutils literal"><span class="pre">noalias</span></tt> is. Furthermore, the semantics of the <tt class="docutils literal"><span class="pre">noalias</span></tt>
+attribute on return values are stronger than the semantics of the attribute
+when used on function arguments. On function return values, the <tt class="docutils literal"><span class="pre">noalias</span></tt>
+attribute indicates that the function acts like a system memory allocation
+function, returning a pointer to allocated storage disjoint from the
+storage for any other object accessible to the caller.</p>
+</dd>
+<dt><tt class="docutils literal"><span class="pre">nocapture</span></tt></dt>
+<dd>This indicates that the callee does not make any copies of the
+pointer that outlive the callee itself. This is not a valid
+attribute for return values.</dd>
+</dl>
+<dl class="docutils" id="nest">
+<dt><tt class="docutils literal"><span class="pre">nest</span></tt></dt>
+<dd>This indicates that the pointer parameter can be excised using the
+<a class="reference internal" href="#int-trampoline"><em>trampoline intrinsics</em></a>. This is not a valid
+attribute for return values and can only be applied to one parameter.</dd>
+<dt><tt class="docutils literal"><span class="pre">returned</span></tt></dt>
+<dd>This indicates that the function always returns the argument as its return
+value. This is an optimization hint to the code generator when generating
+the caller, allowing tail call optimization and omission of register saves
+and restores in some cases; it is not checked or enforced when generating
+the callee. The parameter and the function return type must be valid
+operands for the <a class="reference internal" href="#i-bitcast"><em>bitcast instruction</em></a>. This is not a
+valid attribute for return values and can only be applied to one parameter.</dd>
+<dt><tt class="docutils literal"><span class="pre">nonnull</span></tt></dt>
+<dd>This indicates that the parameter or return pointer is not null. This
+attribute may only be applied to pointer typed parameters. This is not
+checked or enforced by LLVM, the caller must ensure that the pointer
+passed in is non-null, or the callee must ensure that the returned pointer
+is non-null.</dd>
+<dt><tt class="docutils literal"><span class="pre">dereferenceable(<n>)</span></tt></dt>
+<dd>This indicates that the parameter or return pointer is dereferenceable. This
+attribute may only be applied to pointer typed parameters. A pointer that
+is dereferenceable can be loaded from speculatively without a risk of
+trapping. The number of bytes known to be dereferenceable must be provided
+in parentheses. It is legal for the number of bytes to be less than the
+size of the pointee type. The <tt class="docutils literal"><span class="pre">nonnull</span></tt> attribute does not imply
+dereferenceability (consider a pointer to one element past the end of an
+array), however <tt class="docutils literal"><span class="pre">dereferenceable(<n>)</span></tt> does imply <tt class="docutils literal"><span class="pre">nonnull</span></tt> in
+<tt class="docutils literal"><span class="pre">addrspace(0)</span></tt> (which is the default address space).</dd>
+</dl>
+</div>
+<div class="section" id="garbage-collector-names">
+<span id="gc"></span><h3><a class="toc-backref" href="#id597">Garbage Collector Names</a><a class="headerlink" href="#garbage-collector-names" title="Permalink to this headline">¶</a></h3>
+<p>Each function may specify a garbage collector name, which is simply a
+string:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="k">define</span> <span class="kt">void</span> <span class="vg">@f</span><span class="p">()</span> <span class="k">gc</span> <span class="s">"name"</span> <span class="p">{</span> <span class="p">...</span> <span class="p">}</span>
+</pre></div>
+</div>
+<p>The compiler declares the supported values of <em>name</em>. Specifying a
+collector will cause the compiler to alter its output in order to
+support the named garbage collection algorithm.</p>
+</div>
+<div class="section" id="prefix-data">
+<span id="prefixdata"></span><h3><a class="toc-backref" href="#id598">Prefix Data</a><a class="headerlink" href="#prefix-data" title="Permalink to this headline">¶</a></h3>
+<p>Prefix data is data associated with a function which the code
+generator will emit immediately before the function’s entrypoint.
+The purpose of this feature is to allow frontends to associate
+language-specific runtime metadata with specific functions and make it
+available through the function pointer while still allowing the
+function pointer to be called.</p>
+<p>To access the data for a given function, a program may bitcast the
+function pointer to a pointer to the constant’s type and dereference
+index -1.  This implies that the IR symbol points just past the end of
+the prefix data. For instance, take the example of a function annotated
+with a single <tt class="docutils literal"><span class="pre">i32</span></tt>,</p>
+<div class="highlight-llvm"><div class="highlight"><pre>define void @f() prefix i32 123 { ... }
+</pre></div>
+</div>
+<p>The prefix data can be referenced as,</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv-Anonymous">%0</span> <span class="p">=</span> <span class="k">bitcast</span> <span class="p">*</span><span class="kt">void</span> <span class="p">()</span> <span class="vg">@f</span> <span class="k">to</span> <span class="p">*</span><span class="k">i32</span>
+<span class="nv">%a</span> <span class="p">=</span> <span class="k">getelementptr</span> <span class="k">inbounds</span> <span class="p">*</span><span class="k">i32</span> <span class="nv-Anonymous">%0</span><span class="p">,</span> <span class="k">i32</span> <span class="m">-1</span>
+<span class="nv">%b</span> <span class="p">=</span> <span class="k">load</span> <span class="k">i32</span><span class="p">*</span> <span class="nv">%a</span>
+</pre></div>
+</div>
+<p>Prefix data is laid out as if it were an initializer for a global variable
+of the prefix data’s type.  The function will be placed such that the
+beginning of the prefix data is aligned. This means that if the size
+of the prefix data is not a multiple of the alignment size, the
+function’s entrypoint will not be aligned. If alignment of the
+function’s entrypoint is desired, padding must be added to the prefix
+data.</p>
+<p>A function may have prefix data but no body.  This has similar semantics
+to the <tt class="docutils literal"><span class="pre">available_externally</span></tt> linkage in that the data may be used by the
+optimizers but will not be emitted in the object file.</p>
+</div>
+<div class="section" id="prologue-data">
+<span id="prologuedata"></span><h3><a class="toc-backref" href="#id599">Prologue Data</a><a class="headerlink" href="#prologue-data" title="Permalink to this headline">¶</a></h3>
+<p>The <tt class="docutils literal"><span class="pre">prologue</span></tt> attribute allows arbitrary code (encoded as bytes) to
+be inserted prior to the function body. This can be used for enabling
+function hot-patching and instrumentation.</p>
+<p>To maintain the semantics of ordinary function calls, the prologue data must
+have a particular format.  Specifically, it must begin with a sequence of
+bytes which decode to a sequence of machine instructions, valid for the
+module’s target, which transfer control to the point immediately succeeding
+the prologue data, without performing any other visible action.  This allows
+the inliner and other passes to reason about the semantics of the function
+definition without needing to reason about the prologue data.  Obviously this
+makes the format of the prologue data highly target dependent.</p>
+<p>A trivial example of valid prologue data for the x86 architecture is <tt class="docutils literal"><span class="pre">i8</span> <span class="pre">144</span></tt>,
+which encodes the <tt class="docutils literal"><span class="pre">nop</span></tt> instruction:</p>
+<div class="highlight-llvm"><div class="highlight"><pre>define void @f() prologue i8 144 { ... }
+</pre></div>
+</div>
+<p>Generally prologue data can be formed by encoding a relative branch instruction
+which skips the metadata, as in this example of valid prologue data for the
+x86_64 architecture, where the first two bytes encode <tt class="docutils literal"><span class="pre">jmp</span> <span class="pre">.+10</span></tt>:</p>
+<div class="highlight-llvm"><div class="highlight"><pre>%0 = type <{ i8, i8, i8* }>
+
+define void @f() prologue %0 <{ i8 235, i8 8, i8* @md}> { ... }
+</pre></div>
+</div>
+<p>A function may have prologue data but no body.  This has similar semantics
+to the <tt class="docutils literal"><span class="pre">available_externally</span></tt> linkage in that the data may be used by the
+optimizers but will not be emitted in the object file.</p>
+</div>
+<div class="section" id="attribute-groups">
+<span id="attrgrp"></span><h3><a class="toc-backref" href="#id600">Attribute Groups</a><a class="headerlink" href="#attribute-groups" title="Permalink to this headline">¶</a></h3>
+<p>Attribute groups are groups of attributes that are referenced by objects within
+the IR. They are important for keeping <tt class="docutils literal"><span class="pre">.ll</span></tt> files readable, because a lot of
+functions will use the same set of attributes. In the degenerative case of a
+<tt class="docutils literal"><span class="pre">.ll</span></tt> file that corresponds to a single <tt class="docutils literal"><span class="pre">.c</span></tt> file, the single attribute
+group will capture the important command line flags used to build that file.</p>
+<p>An attribute group is a module-level object. To use an attribute group, an
+object references the attribute group’s ID (e.g. <tt class="docutils literal"><span class="pre">#37</span></tt>). An object may refer
+to more than one attribute group. In that situation, the attributes from the
+different groups are merged.</p>
+<p>Here is an example of attribute groups for a function that should always be
+inlined, has a stack alignment of 4, and which shouldn’t use SSE instructions:</p>
+<div class="highlight-llvm"><div class="highlight"><pre>; Target-independent attributes:
+attributes #0 = { alwaysinline alignstack=4 }
+
+; Target-dependent attributes:
+attributes #1 = { "no-sse" }
+
+; Function @f has attributes: alwaysinline, alignstack=4, and "no-sse".
+define void @f() #0 #1 { ... }
+</pre></div>
+</div>
+</div>
+<div class="section" id="function-attributes">
+<span id="fnattrs"></span><h3><a class="toc-backref" href="#id601">Function Attributes</a><a class="headerlink" href="#function-attributes" title="Permalink to this headline">¶</a></h3>
+<p>Function attributes are set to communicate additional information about
+a function. Function attributes are considered to be part of the
+function, not of the function type, so functions with different function
+attributes can have the same function type.</p>
+<p>Function attributes are simple keywords that follow the type specified.
+If multiple attributes are needed, they are space separated. For
+example:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="k">define</span> <span class="kt">void</span> <span class="vg">@f</span><span class="p">()</span> <span class="k">noinline</span> <span class="p">{</span> <span class="p">...</span> <span class="p">}</span>
+<span class="k">define</span> <span class="kt">void</span> <span class="vg">@f</span><span class="p">()</span> <span class="k">alwaysinline</span> <span class="p">{</span> <span class="p">...</span> <span class="p">}</span>
+<span class="k">define</span> <span class="kt">void</span> <span class="vg">@f</span><span class="p">()</span> <span class="k">alwaysinline</span> <span class="k">optsize</span> <span class="p">{</span> <span class="p">...</span> <span class="p">}</span>
+<span class="k">define</span> <span class="kt">void</span> <span class="vg">@f</span><span class="p">()</span> <span class="k">optsize</span> <span class="p">{</span> <span class="p">...</span> <span class="p">}</span>
+</pre></div>
+</div>
+<dl class="docutils">
+<dt><tt class="docutils literal"><span class="pre">alignstack(<n>)</span></tt></dt>
+<dd>This attribute indicates that, when emitting the prologue and
+epilogue, the backend should forcibly align the stack pointer.
+Specify the desired alignment, which must be a power of two, in
+parentheses.</dd>
+<dt><tt class="docutils literal"><span class="pre">alwaysinline</span></tt></dt>
+<dd>This attribute indicates that the inliner should attempt to inline
+this function into callers whenever possible, ignoring any active
+inlining size threshold for this caller.</dd>
+<dt><tt class="docutils literal"><span class="pre">builtin</span></tt></dt>
+<dd>This indicates that the callee function at a call site should be
+recognized as a built-in function, even though the function’s declaration
+uses the <tt class="docutils literal"><span class="pre">nobuiltin</span></tt> attribute. This is only valid at call sites for
+direct calls to functions that are declared with the <tt class="docutils literal"><span class="pre">nobuiltin</span></tt>
+attribute.</dd>
+<dt><tt class="docutils literal"><span class="pre">cold</span></tt></dt>
+<dd>This attribute indicates that this function is rarely called. When
+computing edge weights, basic blocks post-dominated by a cold
+function call are also considered to be cold; and, thus, given low
+weight.</dd>
+<dt><tt class="docutils literal"><span class="pre">inlinehint</span></tt></dt>
+<dd>This attribute indicates that the source code contained a hint that
+inlining this function is desirable (such as the “inline” keyword in
+C/C++). It is just a hint; it imposes no requirements on the
+inliner.</dd>
+<dt><tt class="docutils literal"><span class="pre">jumptable</span></tt></dt>
+<dd>This attribute indicates that the function should be added to a
+jump-instruction table at code-generation time, and that all address-taken
+references to this function should be replaced with a reference to the
+appropriate jump-instruction-table function pointer. Note that this creates
+a new pointer for the original function, which means that code that depends
+on function-pointer identity can break. So, any function annotated with
+<tt class="docutils literal"><span class="pre">jumptable</span></tt> must also be <tt class="docutils literal"><span class="pre">unnamed_addr</span></tt>.</dd>
+<dt><tt class="docutils literal"><span class="pre">minsize</span></tt></dt>
+<dd>This attribute suggests that optimization passes and code generator
+passes make choices that keep the code size of this function as small
+as possible and perform optimizations that may sacrifice runtime
+performance in order to minimize the size of the generated code.</dd>
+<dt><tt class="docutils literal"><span class="pre">naked</span></tt></dt>
+<dd>This attribute disables prologue / epilogue emission for the
+function. This can have very system-specific consequences.</dd>
+<dt><tt class="docutils literal"><span class="pre">nobuiltin</span></tt></dt>
+<dd>This indicates that the callee function at a call site is not recognized as
+a built-in function. LLVM will retain the original call and not replace it
+with equivalent code based on the semantics of the built-in function, unless
+the call site uses the <tt class="docutils literal"><span class="pre">builtin</span></tt> attribute. This is valid at call sites
+and on function declarations and definitions.</dd>
+<dt><tt class="docutils literal"><span class="pre">noduplicate</span></tt></dt>
+<dd><p class="first">This attribute indicates that calls to the function cannot be
+duplicated. A call to a <tt class="docutils literal"><span class="pre">noduplicate</span></tt> function may be moved
+within its parent function, but may not be duplicated within
+its parent function.</p>
+<p class="last">A function containing a <tt class="docutils literal"><span class="pre">noduplicate</span></tt> call may still
+be an inlining candidate, provided that the call is not
+duplicated by inlining. That implies that the function has
+internal linkage and only has one call site, so the original
+call is dead after inlining.</p>
+</dd>
+<dt><tt class="docutils literal"><span class="pre">noimplicitfloat</span></tt></dt>
+<dd>This attributes disables implicit floating point instructions.</dd>
+<dt><tt class="docutils literal"><span class="pre">noinline</span></tt></dt>
+<dd>This attribute indicates that the inliner should never inline this
+function in any situation. This attribute may not be used together
+with the <tt class="docutils literal"><span class="pre">alwaysinline</span></tt> attribute.</dd>
+<dt><tt class="docutils literal"><span class="pre">nonlazybind</span></tt></dt>
+<dd>This attribute suppresses lazy symbol binding for the function. This
+may make calls to the function faster, at the cost of extra program
+startup time if the function is not called during program startup.</dd>
+<dt><tt class="docutils literal"><span class="pre">noredzone</span></tt></dt>
+<dd>This attribute indicates that the code generator should not use a
+red zone, even if the target-specific ABI normally permits it.</dd>
+<dt><tt class="docutils literal"><span class="pre">noreturn</span></tt></dt>
+<dd>This function attribute indicates that the function never returns
+normally. This produces undefined behavior at runtime if the
+function ever does dynamically return.</dd>
+<dt><tt class="docutils literal"><span class="pre">nounwind</span></tt></dt>
+<dd>This function attribute indicates that the function never returns
+with an unwind or exceptional control flow. If the function does
+unwind, its runtime behavior is undefined.</dd>
+<dt><tt class="docutils literal"><span class="pre">optnone</span></tt></dt>
+<dd><p class="first">This function attribute indicates that the function is not optimized
+by any optimization or code generator passes with the
+exception of interprocedural optimization passes.
+This attribute cannot be used together with the <tt class="docutils literal"><span class="pre">alwaysinline</span></tt>
+attribute; this attribute is also incompatible
+with the <tt class="docutils literal"><span class="pre">minsize</span></tt> attribute and the <tt class="docutils literal"><span class="pre">optsize</span></tt> attribute.</p>
+<p class="last">This attribute requires the <tt class="docutils literal"><span class="pre">noinline</span></tt> attribute to be specified on
+the function as well, so the function is never inlined into any caller.
+Only functions with the <tt class="docutils literal"><span class="pre">alwaysinline</span></tt> attribute are valid
+candidates for inlining into the body of this function.</p>
+</dd>
+<dt><tt class="docutils literal"><span class="pre">optsize</span></tt></dt>
+<dd>This attribute suggests that optimization passes and code generator
+passes make choices that keep the code size of this function low,
+and otherwise do optimizations specifically to reduce code size as
+long as they do not significantly impact runtime performance.</dd>
+<dt><tt class="docutils literal"><span class="pre">readnone</span></tt></dt>
+<dd><p class="first">On a function, this attribute indicates that the function computes its
+result (or decides to unwind an exception) based strictly on its arguments,
+without dereferencing any pointer arguments or otherwise accessing
+any mutable state (e.g. memory, control registers, etc) visible to
+caller functions. It does not write through any pointer arguments
+(including <tt class="docutils literal"><span class="pre">byval</span></tt> arguments) and never changes any state visible
+to callers. This means that it cannot unwind exceptions by calling
+the <tt class="docutils literal"><span class="pre">C++</span></tt> exception throwing methods.</p>
+<p class="last">On an argument, this attribute indicates that the function does not
+dereference that pointer argument, even though it may read or write the
+memory that the pointer points to if accessed through other pointers.</p>
+</dd>
+<dt><tt class="docutils literal"><span class="pre">readonly</span></tt></dt>
+<dd><p class="first">On a function, this attribute indicates that the function does not write
+through any pointer arguments (including <tt class="docutils literal"><span class="pre">byval</span></tt> arguments) or otherwise
+modify any state (e.g. memory, control registers, etc) visible to
+caller functions. It may dereference pointer arguments and read
+state that may be set in the caller. A readonly function always
+returns the same value (or unwinds an exception identically) when
+called with the same set of arguments and global state. It cannot
+unwind an exception by calling the <tt class="docutils literal"><span class="pre">C++</span></tt> exception throwing
+methods.</p>
+<p class="last">On an argument, this attribute indicates that the function does not write
+through this pointer argument, even though it may write to the memory that
+the pointer points to.</p>
+</dd>
+<dt><tt class="docutils literal"><span class="pre">returns_twice</span></tt></dt>
+<dd>This attribute indicates that this function can return twice. The C
+<tt class="docutils literal"><span class="pre">setjmp</span></tt> is an example of such a function. The compiler disables
+some optimizations (like tail calls) in the caller of these
+functions.</dd>
+<dt><tt class="docutils literal"><span class="pre">sanitize_address</span></tt></dt>
+<dd>This attribute indicates that AddressSanitizer checks
+(dynamic address safety analysis) are enabled for this function.</dd>
+<dt><tt class="docutils literal"><span class="pre">sanitize_memory</span></tt></dt>
+<dd>This attribute indicates that MemorySanitizer checks (dynamic detection
+of accesses to uninitialized memory) are enabled for this function.</dd>
+<dt><tt class="docutils literal"><span class="pre">sanitize_thread</span></tt></dt>
+<dd>This attribute indicates that ThreadSanitizer checks
+(dynamic thread safety analysis) are enabled for this function.</dd>
+<dt><tt class="docutils literal"><span class="pre">ssp</span></tt></dt>
+<dd><p class="first">This attribute indicates that the function should emit a stack
+smashing protector. It is in the form of a “canary” — a random value
+placed on the stack before the local variables that’s checked upon
+return from the function to see if it has been overwritten. A
+heuristic is used to determine if a function needs stack protectors
+or not. The heuristic used will enable protectors for functions with:</p>
+<ul class="simple">
+<li>Character arrays larger than <tt class="docutils literal"><span class="pre">ssp-buffer-size</span></tt> (default 8).</li>
+<li>Aggregates containing character arrays larger than <tt class="docutils literal"><span class="pre">ssp-buffer-size</span></tt>.</li>
+<li>Calls to alloca() with variable sizes or constant sizes greater than
+<tt class="docutils literal"><span class="pre">ssp-buffer-size</span></tt>.</li>
+</ul>
+<p>Variables that are identified as requiring a protector will be arranged
+on the stack such that they are adjacent to the stack protector guard.</p>
+<p class="last">If a function that has an <tt class="docutils literal"><span class="pre">ssp</span></tt> attribute is inlined into a
+function that doesn’t have an <tt class="docutils literal"><span class="pre">ssp</span></tt> attribute, then the resulting
+function will have an <tt class="docutils literal"><span class="pre">ssp</span></tt> attribute.</p>
+</dd>
+<dt><tt class="docutils literal"><span class="pre">sspreq</span></tt></dt>
+<dd><p class="first">This attribute indicates that the function should <em>always</em> emit a
+stack smashing protector. This overrides the <tt class="docutils literal"><span class="pre">ssp</span></tt> function
+attribute.</p>
+<p>Variables that are identified as requiring a protector will be arranged
+on the stack such that they are adjacent to the stack protector guard.
+The specific layout rules are:</p>
+<ol class="arabic simple">
+<li>Large arrays and structures containing large arrays
+(<tt class="docutils literal"><span class="pre">>=</span> <span class="pre">ssp-buffer-size</span></tt>) are closest to the stack protector.</li>
+<li>Small arrays and structures containing small arrays
+(<tt class="docutils literal"><span class="pre"><</span> <span class="pre">ssp-buffer-size</span></tt>) are 2nd closest to the protector.</li>
+<li>Variables that have had their address taken are 3rd closest to the
+protector.</li>
+</ol>
+<p class="last">If a function that has an <tt class="docutils literal"><span class="pre">sspreq</span></tt> attribute is inlined into a
+function that doesn’t have an <tt class="docutils literal"><span class="pre">sspreq</span></tt> attribute or which has an
+<tt class="docutils literal"><span class="pre">ssp</span></tt> or <tt class="docutils literal"><span class="pre">sspstrong</span></tt> attribute, then the resulting function will have
+an <tt class="docutils literal"><span class="pre">sspreq</span></tt> attribute.</p>
+</dd>
+<dt><tt class="docutils literal"><span class="pre">sspstrong</span></tt></dt>
+<dd><p class="first">This attribute indicates that the function should emit a stack smashing
+protector. This attribute causes a strong heuristic to be used when
+determining if a function needs stack protectors.  The strong heuristic
+will enable protectors for functions with:</p>
+<ul class="simple">
+<li>Arrays of any size and type</li>
+<li>Aggregates containing an array of any size and type.</li>
+<li>Calls to alloca().</li>
+<li>Local variables that have had their address taken.</li>
+</ul>
+<p>Variables that are identified as requiring a protector will be arranged
+on the stack such that they are adjacent to the stack protector guard.
+The specific layout rules are:</p>
+<ol class="arabic simple">
+<li>Large arrays and structures containing large arrays
+(<tt class="docutils literal"><span class="pre">>=</span> <span class="pre">ssp-buffer-size</span></tt>) are closest to the stack protector.</li>
+<li>Small arrays and structures containing small arrays
+(<tt class="docutils literal"><span class="pre"><</span> <span class="pre">ssp-buffer-size</span></tt>) are 2nd closest to the protector.</li>
+<li>Variables that have had their address taken are 3rd closest to the
+protector.</li>
+</ol>
+<p>This overrides the <tt class="docutils literal"><span class="pre">ssp</span></tt> function attribute.</p>
+<p class="last">If a function that has an <tt class="docutils literal"><span class="pre">sspstrong</span></tt> attribute is inlined into a
+function that doesn’t have an <tt class="docutils literal"><span class="pre">sspstrong</span></tt> attribute, then the
+resulting function will have an <tt class="docutils literal"><span class="pre">sspstrong</span></tt> attribute.</p>
+</dd>
+<dt><tt class="docutils literal"><span class="pre">uwtable</span></tt></dt>
+<dd>This attribute indicates that the ABI being targeted requires that
+an unwind table entry be produce for this function even if we can
+show that no exceptions passes by it. This is normally the case for
+the ELF x86-64 abi, but it can be disabled for some compilation
+units.</dd>
+</dl>
+</div>
+<div class="section" id="module-level-inline-assembly">
+<span id="moduleasm"></span><h3><a class="toc-backref" href="#id602">Module-Level Inline Assembly</a><a class="headerlink" href="#module-level-inline-assembly" title="Permalink to this headline">¶</a></h3>
+<p>Modules may contain “module-level inline asm” blocks, which corresponds
+to the GCC “file scope inline asm” blocks. These blocks are internally
+concatenated by LLVM and treated as a single unit, but may be separated
+in the <tt class="docutils literal"><span class="pre">.ll</span></tt> file if desired. The syntax is very simple:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="k">module</span> <span class="k">asm</span> <span class="s">"inline asm code goes here"</span>
+<span class="k">module</span> <span class="k">asm</span> <span class="s">"more can go here"</span>
+</pre></div>
+</div>
+<p>The strings can contain any character by escaping non-printable
+characters. The escape sequence used is simply “\xx” where “xx” is the
+two digit hex code for the number.</p>
+<p>The inline asm code is simply printed to the machine code .s file when
+assembly code is generated.</p>
+</div>
+<div class="section" id="data-layout">
+<span id="langref-datalayout"></span><h3><a class="toc-backref" href="#id603">Data Layout</a><a class="headerlink" href="#data-layout" title="Permalink to this headline">¶</a></h3>
+<p>A module may specify a target specific data layout string that specifies
+how data is to be laid out in memory. The syntax for the data layout is
+simply:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="k">target</span> <span class="k">datalayout</span> <span class="p">=</span> <span class="s">"layout specification"</span>
+</pre></div>
+</div>
+<p>The <em>layout specification</em> consists of a list of specifications
+separated by the minus sign character (‘-‘). Each specification starts
+with a letter and may include other information after the letter to
+define some aspect of the data layout. The specifications accepted are
+as follows:</p>
+<dl class="docutils">
+<dt><tt class="docutils literal"><span class="pre">E</span></tt></dt>
+<dd>Specifies that the target lays out data in big-endian form. That is,
+the bits with the most significance have the lowest address
+location.</dd>
+<dt><tt class="docutils literal"><span class="pre">e</span></tt></dt>
+<dd>Specifies that the target lays out data in little-endian form. That
+is, the bits with the least significance have the lowest address
+location.</dd>
+<dt><tt class="docutils literal"><span class="pre">S<size></span></tt></dt>
+<dd>Specifies the natural alignment of the stack in bits. Alignment
+promotion of stack variables is limited to the natural stack
+alignment to avoid dynamic stack realignment. The stack alignment
+must be a multiple of 8-bits. If omitted, the natural stack
+alignment defaults to “unspecified”, which does not prevent any
+alignment promotions.</dd>
+<dt><tt class="docutils literal"><span class="pre">p[n]:<size>:<abi>:<pref></span></tt></dt>
+<dd>This specifies the <em>size</em> of a pointer and its <tt class="docutils literal"><span class="pre"><abi></span></tt> and
+<tt class="docutils literal"><span class="pre"><pref></span></tt>erred alignments for address space <tt class="docutils literal"><span class="pre">n</span></tt>. All sizes are in
+bits. The address space, <tt class="docutils literal"><span class="pre">n</span></tt> is optional, and if not specified,
+denotes the default address space 0.  The value of <tt class="docutils literal"><span class="pre">n</span></tt> must be
+in the range [1,2^23).</dd>
+<dt><tt class="docutils literal"><span class="pre">i<size>:<abi>:<pref></span></tt></dt>
+<dd>This specifies the alignment for an integer type of a given bit
+<tt class="docutils literal"><span class="pre"><size></span></tt>. The value of <tt class="docutils literal"><span class="pre"><size></span></tt> must be in the range [1,2^23).</dd>
+<dt><tt class="docutils literal"><span class="pre">v<size>:<abi>:<pref></span></tt></dt>
+<dd>This specifies the alignment for a vector type of a given bit
+<tt class="docutils literal"><span class="pre"><size></span></tt>.</dd>
+<dt><tt class="docutils literal"><span class="pre">f<size>:<abi>:<pref></span></tt></dt>
+<dd>This specifies the alignment for a floating point type of a given bit
+<tt class="docutils literal"><span class="pre"><size></span></tt>. Only values of <tt class="docutils literal"><span class="pre"><size></span></tt> that are supported by the target
+will work. 32 (float) and 64 (double) are supported on all targets; 80
+or 128 (different flavors of long double) are also supported on some
+targets.</dd>
+<dt><tt class="docutils literal"><span class="pre">a:<abi>:<pref></span></tt></dt>
+<dd>This specifies the alignment for an object of aggregate type.</dd>
+<dt><tt class="docutils literal"><span class="pre">m:<mangling></span></tt></dt>
+<dd><p class="first">If present, specifies that llvm names are mangled in the output. The
+options are</p>
+<ul class="last simple">
+<li><tt class="docutils literal"><span class="pre">e</span></tt>: ELF mangling: Private symbols get a <tt class="docutils literal"><span class="pre">.L</span></tt> prefix.</li>
+<li><tt class="docutils literal"><span class="pre">m</span></tt>: Mips mangling: Private symbols get a <tt class="docutils literal"><span class="pre">$</span></tt> prefix.</li>
+<li><tt class="docutils literal"><span class="pre">o</span></tt>: Mach-O mangling: Private symbols get <tt class="docutils literal"><span class="pre">L</span></tt> prefix. Other
+symbols get a <tt class="docutils literal"><span class="pre">_</span></tt> prefix.</li>
+<li><tt class="docutils literal"><span class="pre">w</span></tt>: Windows COFF prefix:  Similar to Mach-O, but stdcall and fastcall
+functions also get a suffix based on the frame size.</li>
+</ul>
+</dd>
+<dt><tt class="docutils literal"><span class="pre">n<size1>:<size2>:<size3>...</span></tt></dt>
+<dd>This specifies a set of native integer widths for the target CPU in
+bits. For example, it might contain <tt class="docutils literal"><span class="pre">n32</span></tt> for 32-bit PowerPC,
+<tt class="docutils literal"><span class="pre">n32:64</span></tt> for PowerPC 64, or <tt class="docutils literal"><span class="pre">n8:16:32:64</span></tt> for X86-64. Elements of
+this set are considered to support most general arithmetic operations
+efficiently.</dd>
+</dl>
+<p>On every specification that takes a <tt class="docutils literal"><span class="pre"><abi>:<pref></span></tt>, specifying the
+<tt class="docutils literal"><span class="pre"><pref></span></tt> alignment is optional. If omitted, the preceding <tt class="docutils literal"><span class="pre">:</span></tt>
+should be omitted too and <tt class="docutils literal"><span class="pre"><pref></span></tt> will be equal to <tt class="docutils literal"><span class="pre"><abi></span></tt>.</p>
+<p>When constructing the data layout for a given target, LLVM starts with a
+default set of specifications which are then (possibly) overridden by
+the specifications in the <tt class="docutils literal"><span class="pre">datalayout</span></tt> keyword. The default
+specifications are given in this list:</p>
+<ul class="simple">
+<li><tt class="docutils literal"><span class="pre">E</span></tt> - big endian</li>
+<li><tt class="docutils literal"><span class="pre">p:64:64:64</span></tt> - 64-bit pointers with 64-bit alignment.</li>
+<li><tt class="docutils literal"><span class="pre">p[n]:64:64:64</span></tt> - Other address spaces are assumed to be the
+same as the default address space.</li>
+<li><tt class="docutils literal"><span class="pre">S0</span></tt> - natural stack alignment is unspecified</li>
+<li><tt class="docutils literal"><span class="pre">i1:8:8</span></tt> - i1 is 8-bit (byte) aligned</li>
+<li><tt class="docutils literal"><span class="pre">i8:8:8</span></tt> - i8 is 8-bit (byte) aligned</li>
+<li><tt class="docutils literal"><span class="pre">i16:16:16</span></tt> - i16 is 16-bit aligned</li>
+<li><tt class="docutils literal"><span class="pre">i32:32:32</span></tt> - i32 is 32-bit aligned</li>
+<li><tt class="docutils literal"><span class="pre">i64:32:64</span></tt> - i64 has ABI alignment of 32-bits but preferred
+alignment of 64-bits</li>
+<li><tt class="docutils literal"><span class="pre">f16:16:16</span></tt> - half is 16-bit aligned</li>
+<li><tt class="docutils literal"><span class="pre">f32:32:32</span></tt> - float is 32-bit aligned</li>
+<li><tt class="docutils literal"><span class="pre">f64:64:64</span></tt> - double is 64-bit aligned</li>
+<li><tt class="docutils literal"><span class="pre">f128:128:128</span></tt> - quad is 128-bit aligned</li>
+<li><tt class="docutils literal"><span class="pre">v64:64:64</span></tt> - 64-bit vector is 64-bit aligned</li>
+<li><tt class="docutils literal"><span class="pre">v128:128:128</span></tt> - 128-bit vector is 128-bit aligned</li>
+<li><tt class="docutils literal"><span class="pre">a:0:64</span></tt> - aggregates are 64-bit aligned</li>
+</ul>
+<p>When LLVM is determining the alignment for a given type, it uses the
+following rules:</p>
+<ol class="arabic simple">
+<li>If the type sought is an exact match for one of the specifications,
+that specification is used.</li>
+<li>If no match is found, and the type sought is an integer type, then
+the smallest integer type that is larger than the bitwidth of the
+sought type is used. If none of the specifications are larger than
+the bitwidth then the largest integer type is used. For example,
+given the default specifications above, the i7 type will use the
+alignment of i8 (next largest) while both i65 and i256 will use the
+alignment of i64 (largest specified).</li>
+<li>If no match is found, and the type sought is a vector type, then the
+largest vector type that is smaller than the sought vector type will
+be used as a fall back. This happens because <128 x double> can be
+implemented in terms of 64 <2 x double>, for example.</li>
+</ol>
+<p>The function of the data layout string may not be what you expect.
+Notably, this is not a specification from the frontend of what alignment
+the code generator should use.</p>
+<p>Instead, if specified, the target data layout is required to match what
+the ultimate <em>code generator</em> expects. This string is used by the
+mid-level optimizers to improve code, and this only works if it matches
+what the ultimate code generator uses. If you would like to generate IR
+that does not embed this target-specific detail into the IR, then you
+don’t have to specify the string. This will disable some optimizations
+that require precise layout information, but this also prevents those
+optimizations from introducing target specificity into the IR.</p>
+</div>
+<div class="section" id="target-triple">
+<span id="langref-triple"></span><h3><a class="toc-backref" href="#id604">Target Triple</a><a class="headerlink" href="#target-triple" title="Permalink to this headline">¶</a></h3>
+<p>A module may specify a target triple string that describes the target
+host. The syntax for the target triple is simply:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="k">target</span> <span class="k">triple</span> <span class="p">=</span> <span class="s">"x86_64-apple-macosx10.7.0"</span>
+</pre></div>
+</div>
+<p>The <em>target triple</em> string consists of a series of identifiers delimited
+by the minus sign character (‘-‘). The canonical forms are:</p>
+<div class="highlight-python"><div class="highlight"><pre><span class="n">ARCHITECTURE</span><span class="o">-</span><span class="n">VENDOR</span><span class="o">-</span><span class="n">OPERATING_SYSTEM</span>
+<span class="n">ARCHITECTURE</span><span class="o">-</span><span class="n">VENDOR</span><span class="o">-</span><span class="n">OPERATING_SYSTEM</span><span class="o">-</span><span class="n">ENVIRONMENT</span>
+</pre></div>
+</div>
+<p>This information is passed along to the backend so that it generates
+code for the proper architecture. It’s possible to override this on the
+command line with the <tt class="docutils literal"><span class="pre">-mtriple</span></tt> command line option.</p>
+</div>
+<div class="section" id="pointer-aliasing-rules">
+<span id="pointeraliasing"></span><h3><a class="toc-backref" href="#id605">Pointer Aliasing Rules</a><a class="headerlink" href="#pointer-aliasing-rules" title="Permalink to this headline">¶</a></h3>
+<p>Any memory access must be done through a pointer value associated with
+an address range of the memory access, otherwise the behavior is
+undefined. Pointer values are associated with address ranges according
+to the following rules:</p>
+<ul class="simple">
+<li>A pointer value is associated with the addresses associated with any
+value it is <em>based</em> on.</li>
+<li>An address of a global variable is associated with the address range
+of the variable’s storage.</li>
+<li>The result value of an allocation instruction is associated with the
+address range of the allocated storage.</li>
+<li>A null pointer in the default address-space is associated with no
+address.</li>
+<li>An integer constant other than zero or a pointer value returned from
+a function not defined within LLVM may be associated with address
+ranges allocated through mechanisms other than those provided by
+LLVM. Such ranges shall not overlap with any ranges of addresses
+allocated by mechanisms provided by LLVM.</li>
+</ul>
+<p>A pointer value is <em>based</em> on another pointer value according to the
+following rules:</p>
+<ul class="simple">
+<li>A pointer value formed from a <tt class="docutils literal"><span class="pre">getelementptr</span></tt> operation is <em>based</em>
+on the first operand of the <tt class="docutils literal"><span class="pre">getelementptr</span></tt>.</li>
+<li>The result value of a <tt class="docutils literal"><span class="pre">bitcast</span></tt> is <em>based</em> on the operand of the
+<tt class="docutils literal"><span class="pre">bitcast</span></tt>.</li>
+<li>A pointer value formed by an <tt class="docutils literal"><span class="pre">inttoptr</span></tt> is <em>based</em> on all pointer
+values that contribute (directly or indirectly) to the computation of
+the pointer’s value.</li>
+<li>The “<em>based</em> on” relationship is transitive.</li>
+</ul>
+<p>Note that this definition of <em>“based”</em> is intentionally similar to the
+definition of <em>“based”</em> in C99, though it is slightly weaker.</p>
+<p>LLVM IR does not associate types with memory. The result type of a
+<tt class="docutils literal"><span class="pre">load</span></tt> merely indicates the size and alignment of the memory from
+which to load, as well as the interpretation of the value. The first
+operand type of a <tt class="docutils literal"><span class="pre">store</span></tt> similarly only indicates the size and
+alignment of the store.</p>
+<p>Consequently, type-based alias analysis, aka TBAA, aka
+<tt class="docutils literal"><span class="pre">-fstrict-aliasing</span></tt>, is not applicable to general unadorned LLVM IR.
+<a class="reference internal" href="#metadata"><em>Metadata</em></a> may be used to encode additional information
+which specialized optimization passes may use to implement type-based
+alias analysis.</p>
+</div>
+<div class="section" id="volatile-memory-accesses">
+<span id="volatile"></span><h3><a class="toc-backref" href="#id606">Volatile Memory Accesses</a><a class="headerlink" href="#volatile-memory-accesses" title="Permalink to this headline">¶</a></h3>
+<p>Certain memory accesses, such as <a class="reference internal" href="#i-load"><em>load</em></a>‘s,
+<a class="reference internal" href="#i-store"><em>store</em></a>‘s, and <a class="reference internal" href="#int-memcpy"><em>llvm.memcpy</em></a>‘s may be
+marked <tt class="docutils literal"><span class="pre">volatile</span></tt>. The optimizers must not change the number of
+volatile operations or change their order of execution relative to other
+volatile operations. The optimizers <em>may</em> change the order of volatile
+operations relative to non-volatile operations. This is not Java’s
+“volatile” and has no cross-thread synchronization behavior.</p>
+<p>IR-level volatile loads and stores cannot safely be optimized into
+llvm.memcpy or llvm.memmove intrinsics even when those intrinsics are
+flagged volatile. Likewise, the backend should never split or merge
+target-legal volatile load/store instructions.</p>
+<div class="admonition-rationale admonition">
+<p class="first admonition-title">Rationale</p>
+<p class="last">Platforms may rely on volatile loads and stores of natively supported
+data width to be executed as single instruction. For example, in C
+this holds for an l-value of volatile primitive type with native
+hardware support, but not necessarily for aggregate types. The
+frontend upholds these expectations, which are intentionally
+unspecified in the IR. The rules above ensure that IR transformation
+do not violate the frontend’s contract with the language.</p>
+</div>
+</div>
+<div class="section" id="memory-model-for-concurrent-operations">
+<span id="memmodel"></span><h3><a class="toc-backref" href="#id607">Memory Model for Concurrent Operations</a><a class="headerlink" href="#memory-model-for-concurrent-operations" title="Permalink to this headline">¶</a></h3>
+<p>The LLVM IR does not define any way to start parallel threads of
+execution or to register signal handlers. Nonetheless, there are
+platform-specific ways to create them, and we define LLVM IR’s behavior
+in their presence. This model is inspired by the C++0x memory model.</p>
+<p>For a more informal introduction to this model, see the <a class="reference internal" href="Atomics.html"><em>LLVM Atomic Instructions and Concurrency Guide</em></a>.</p>
+<p>We define a <em>happens-before</em> partial order as the least partial order
+that</p>
+<ul class="simple">
+<li>Is a superset of single-thread program order, and</li>
+<li>When a <em>synchronizes-with</em> <tt class="docutils literal"><span class="pre">b</span></tt>, includes an edge from <tt class="docutils literal"><span class="pre">a</span></tt> to
+<tt class="docutils literal"><span class="pre">b</span></tt>. <em>Synchronizes-with</em> pairs are introduced by platform-specific
+techniques, like pthread locks, thread creation, thread joining,
+etc., and by atomic instructions. (See also <a class="reference internal" href="#ordering"><em>Atomic Memory Ordering
+Constraints</em></a>).</li>
+</ul>
+<p>Note that program order does not introduce <em>happens-before</em> edges
+between a thread and signals executing inside that thread.</p>
+<p>Every (defined) read operation (load instructions, memcpy, atomic
+loads/read-modify-writes, etc.) R reads a series of bytes written by
+(defined) write operations (store instructions, atomic
+stores/read-modify-writes, memcpy, etc.). For the purposes of this
+section, initialized globals are considered to have a write of the
+initializer which is atomic and happens before any other read or write
+of the memory in question. For each byte of a read R, R<sub>byte</sub>
+may see any write to the same byte, except:</p>
+<ul class="simple">
+<li>If write<sub>1</sub>  happens before write<sub>2</sub>, and
+write<sub>2</sub> happens before R<sub>byte</sub>, then
+R<sub>byte</sub> does not see write<sub>1</sub>.</li>
+<li>If R<sub>byte</sub> happens before write<sub>3</sub>, then
+R<sub>byte</sub> does not see write<sub>3</sub>.</li>
+</ul>
+<p>Given that definition, R<sub>byte</sub> is defined as follows:</p>
+<ul class="simple">
+<li>If R is volatile, the result is target-dependent. (Volatile is
+supposed to give guarantees which can support <tt class="docutils literal"><span class="pre">sig_atomic_t</span></tt> in
+C/C++, and may be used for accesses to addresses that do not behave
+like normal memory. It does not generally provide cross-thread
+synchronization.)</li>
+<li>Otherwise, if there is no write to the same byte that happens before
+R<sub>byte</sub>, R<sub>byte</sub> returns <tt class="docutils literal"><span class="pre">undef</span></tt> for that byte.</li>
+<li>Otherwise, if R<sub>byte</sub> may see exactly one write,
+R<sub>byte</sub> returns the value written by that write.</li>
+<li>Otherwise, if R is atomic, and all the writes R<sub>byte</sub> may
+see are atomic, it chooses one of the values written. See the <a class="reference internal" href="#ordering"><em>Atomic
+Memory Ordering Constraints</em></a> section for additional
+constraints on how the choice is made.</li>
+<li>Otherwise R<sub>byte</sub> returns <tt class="docutils literal"><span class="pre">undef</span></tt>.</li>
+</ul>
+<p>R returns the value composed of the series of bytes it read. This
+implies that some bytes within the value may be <tt class="docutils literal"><span class="pre">undef</span></tt> <strong>without</strong>
+the entire value being <tt class="docutils literal"><span class="pre">undef</span></tt>. Note that this only defines the
+semantics of the operation; it doesn’t mean that targets will emit more
+than one instruction to read the series of bytes.</p>
+<p>Note that in cases where none of the atomic intrinsics are used, this
+model places only one restriction on IR transformations on top of what
+is required for single-threaded execution: introducing a store to a byte
+which might not otherwise be stored is not allowed in general.
+(Specifically, in the case where another thread might write to and read
+from an address, introducing a store can change a load that may see
+exactly one write into a load that may see multiple writes.)</p>
+</div>
+<div class="section" id="atomic-memory-ordering-constraints">
+<span id="ordering"></span><h3><a class="toc-backref" href="#id608">Atomic Memory Ordering Constraints</a><a class="headerlink" href="#atomic-memory-ordering-constraints" title="Permalink to this headline">¶</a></h3>
+<p>Atomic instructions (<a class="reference internal" href="#i-cmpxchg"><em>cmpxchg</em></a>,
+<a class="reference internal" href="#i-atomicrmw"><em>atomicrmw</em></a>, <a class="reference internal" href="#i-fence"><em>fence</em></a>,
+<a class="reference internal" href="#i-load"><em>atomic load</em></a>, and <a class="reference internal" href="#i-store"><em>atomic store</em></a>) take
+ordering parameters that determine which other atomic instructions on
+the same address they <em>synchronize with</em>. These semantics are borrowed
+from Java and C++0x, but are somewhat more colloquial. If these
+descriptions aren’t precise enough, check those specs (see spec
+references in the <a class="reference internal" href="Atomics.html"><em>atomics guide</em></a>).
+<a class="reference internal" href="#i-fence"><em>fence</em></a> instructions treat these orderings somewhat
+differently since they don’t take an address. See that instruction’s
+documentation for details.</p>
+<p>For a simpler introduction to the ordering constraints, see the
+<a class="reference internal" href="Atomics.html"><em>LLVM Atomic Instructions and Concurrency Guide</em></a>.</p>
+<dl class="docutils">
+<dt><tt class="docutils literal"><span class="pre">unordered</span></tt></dt>
+<dd>The set of values that can be read is governed by the happens-before
+partial order. A value cannot be read unless some operation wrote
+it. This is intended to provide a guarantee strong enough to model
+Java’s non-volatile shared variables. This ordering cannot be
+specified for read-modify-write operations; it is not strong enough
+to make them atomic in any interesting way.</dd>
+<dt><tt class="docutils literal"><span class="pre">monotonic</span></tt></dt>
+<dd>In addition to the guarantees of <tt class="docutils literal"><span class="pre">unordered</span></tt>, there is a single
+total order for modifications by <tt class="docutils literal"><span class="pre">monotonic</span></tt> operations on each
+address. All modification orders must be compatible with the
+happens-before order. There is no guarantee that the modification
+orders can be combined to a global total order for the whole program
+(and this often will not be possible). The read in an atomic
+read-modify-write operation (<a class="reference internal" href="#i-cmpxchg"><em>cmpxchg</em></a> and
+<a class="reference internal" href="#i-atomicrmw"><em>atomicrmw</em></a>) reads the value in the modification
+order immediately before the value it writes. If one atomic read
+happens before another atomic read of the same address, the later
+read must see the same value or a later value in the address’s
+modification order. This disallows reordering of <tt class="docutils literal"><span class="pre">monotonic</span></tt> (or
+stronger) operations on the same address. If an address is written
+<tt class="docutils literal"><span class="pre">monotonic</span></tt>-ally by one thread, and other threads <tt class="docutils literal"><span class="pre">monotonic</span></tt>-ally
+read that address repeatedly, the other threads must eventually see
+the write. This corresponds to the C++0x/C1x
+<tt class="docutils literal"><span class="pre">memory_order_relaxed</span></tt>.</dd>
+<dt><tt class="docutils literal"><span class="pre">acquire</span></tt></dt>
+<dd>In addition to the guarantees of <tt class="docutils literal"><span class="pre">monotonic</span></tt>, a
+<em>synchronizes-with</em> edge may be formed with a <tt class="docutils literal"><span class="pre">release</span></tt> operation.
+This is intended to model C++’s <tt class="docutils literal"><span class="pre">memory_order_acquire</span></tt>.</dd>
+<dt><tt class="docutils literal"><span class="pre">release</span></tt></dt>
+<dd>In addition to the guarantees of <tt class="docutils literal"><span class="pre">monotonic</span></tt>, if this operation
+writes a value which is subsequently read by an <tt class="docutils literal"><span class="pre">acquire</span></tt>
+operation, it <em>synchronizes-with</em> that operation. (This isn’t a
+complete description; see the C++0x definition of a release
+sequence.) This corresponds to the C++0x/C1x
+<tt class="docutils literal"><span class="pre">memory_order_release</span></tt>.</dd>
+<dt><tt class="docutils literal"><span class="pre">acq_rel</span></tt> (acquire+release)</dt>
+<dd>Acts as both an <tt class="docutils literal"><span class="pre">acquire</span></tt> and <tt class="docutils literal"><span class="pre">release</span></tt> operation on its
+address. This corresponds to the C++0x/C1x <tt class="docutils literal"><span class="pre">memory_order_acq_rel</span></tt>.</dd>
+<dt><tt class="docutils literal"><span class="pre">seq_cst</span></tt> (sequentially consistent)</dt>
+<dd>In addition to the guarantees of <tt class="docutils literal"><span class="pre">acq_rel</span></tt> (<tt class="docutils literal"><span class="pre">acquire</span></tt> for an
+operation that only reads, <tt class="docutils literal"><span class="pre">release</span></tt> for an operation that only
+writes), there is a global total order on all
+sequentially-consistent operations on all addresses, which is
+consistent with the <em>happens-before</em> partial order and with the
+modification orders of all the affected addresses. Each
+sequentially-consistent read sees the last preceding write to the
+same address in this global order. This corresponds to the C++0x/C1x
+<tt class="docutils literal"><span class="pre">memory_order_seq_cst</span></tt> and Java volatile.</dd>
+</dl>
+<p id="singlethread">If an atomic operation is marked <tt class="docutils literal"><span class="pre">singlethread</span></tt>, it only <em>synchronizes
+with</em> or participates in modification and seq_cst total orderings with
+other operations running in the same thread (for example, in signal
+handlers).</p>
+</div>
+<div class="section" id="fast-math-flags">
+<span id="fastmath"></span><h3><a class="toc-backref" href="#id609">Fast-Math Flags</a><a class="headerlink" href="#fast-math-flags" title="Permalink to this headline">¶</a></h3>
+<p>LLVM IR floating-point binary ops (<a class="reference internal" href="#i-fadd"><em>fadd</em></a>,
+<a class="reference internal" href="#i-fsub"><em>fsub</em></a>, <a class="reference internal" href="#i-fmul"><em>fmul</em></a>, <a class="reference internal" href="#i-fdiv"><em>fdiv</em></a>,
+<a class="reference internal" href="#i-frem"><em>frem</em></a>) have the following flags that can set to enable
+otherwise unsafe floating point operations</p>
+<dl class="docutils">
+<dt><tt class="docutils literal"><span class="pre">nnan</span></tt></dt>
+<dd>No NaNs - Allow optimizations to assume the arguments and result are not
+NaN. Such optimizations are required to retain defined behavior over
+NaNs, but the value of the result is undefined.</dd>
+<dt><tt class="docutils literal"><span class="pre">ninf</span></tt></dt>
+<dd>No Infs - Allow optimizations to assume the arguments and result are not
++/-Inf. Such optimizations are required to retain defined behavior over
++/-Inf, but the value of the result is undefined.</dd>
+<dt><tt class="docutils literal"><span class="pre">nsz</span></tt></dt>
+<dd>No Signed Zeros - Allow optimizations to treat the sign of a zero
+argument or result as insignificant.</dd>
+<dt><tt class="docutils literal"><span class="pre">arcp</span></tt></dt>
+<dd>Allow Reciprocal - Allow optimizations to use the reciprocal of an
+argument rather than perform division.</dd>
+<dt><tt class="docutils literal"><span class="pre">fast</span></tt></dt>
+<dd>Fast - Allow algebraically equivalent transformations that may
+dramatically change results in floating point (e.g. reassociate). This
+flag implies all the others.</dd>
+</dl>
+</div>
+<div class="section" id="use-list-order-directives">
+<span id="uselistorder"></span><h3><a class="toc-backref" href="#id610">Use-list Order Directives</a><a class="headerlink" href="#use-list-order-directives" title="Permalink to this headline">¶</a></h3>
+<p>Use-list directives encode the in-memory order of each use-list, allowing the
+order to be recreated.  <tt class="docutils literal"><span class="pre"><order-indexes></span></tt> is a comma-separated list of
+indexes that are assigned to the referenced value’s uses.  The referenced
+value’s use-list is immediately sorted by these indexes.</p>
+<p>Use-list directives may appear at function scope or global scope.  They are not
+instructions, and have no effect on the semantics of the IR.  When they’re at
+function scope, they must appear after the terminator of the final basic block.</p>
+<p>If basic blocks have their address taken via <tt class="docutils literal"><span class="pre">blockaddress()</span></tt> expressions,
+<tt class="docutils literal"><span class="pre">uselistorder_bb</span></tt> can be used to reorder their use-lists from outside their
+function’s scope.</p>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Syntax:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<div class="highlight-python"><div class="highlight"><pre>uselistorder <ty> <value>, { <order-indexes> }
+uselistorder_bb @function, %block { <order-indexes> }
+</pre></div>
+</div>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Examples:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<div class="highlight-python"><div class="highlight"><pre>define void @foo(i32 %arg1, i32 %arg2) {
+entry:
+  ; ... instructions ...
+bb:
+  ; ... instructions ...
+
+  ; At function scope.
+  uselistorder i32 %arg1, { 1, 0, 2 }
+  uselistorder label %bb, { 1, 0 }
+}
+
+; At global scope.
+uselistorder i32* @global, { 1, 2, 0 }
+uselistorder i32 7, { 1, 0 }
+uselistorder i32 (i32) @bar, { 1, 0 }
+uselistorder_bb @foo, %bb, { 5, 1, 3, 2, 0, 4 }
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="type-system">
+<span id="typesystem"></span><h2><a class="toc-backref" href="#id611">Type System</a><a class="headerlink" href="#type-system" title="Permalink to this headline">¶</a></h2>
+<p>The LLVM type system is one of the most important features of the
+intermediate representation. Being typed enables a number of
+optimizations to be performed on the intermediate representation
+directly, without having to do extra analyses on the side before the
+transformation. A strong type system makes it easier to read the
+generated code and enables novel analyses and transformations that are
+not feasible to perform on normal three address code representations.</p>
+<div class="section" id="void-type">
+<span id="t-void"></span><h3><a class="toc-backref" href="#id612">Void Type</a><a class="headerlink" href="#void-type" title="Permalink to this headline">¶</a></h3>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Overview:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<p>The void type does not represent any value and has no size.</p>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Syntax:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<div class="highlight-python"><div class="highlight"><pre><span class="n">void</span>
+</pre></div>
+</div>
+</div>
+<div class="section" id="function-type">
+<span id="t-function"></span><h3><a class="toc-backref" href="#id613">Function Type</a><a class="headerlink" href="#function-type" title="Permalink to this headline">¶</a></h3>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Overview:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<p>The function type can be thought of as a function signature. It consists of a
+return type and a list of formal parameter types. The return type of a function
+type is a void type or first class type — except for <a class="reference internal" href="#t-label"><em>label</em></a>
+and <a class="reference internal" href="#t-metadata"><em>metadata</em></a> types.</p>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Syntax:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<div class="highlight-python"><div class="highlight"><pre><returntype> (<parameter list>)
+</pre></div>
+</div>
+<p>...where ‘<tt class="docutils literal"><span class="pre"><parameter</span> <span class="pre">list></span></tt>‘ is a comma-separated list of type
+specifiers. Optionally, the parameter list may include a type <tt class="docutils literal"><span class="pre">...</span></tt>, which
+indicates that the function takes a variable number of arguments.  Variable
+argument functions can access their arguments with the <a class="reference internal" href="#int-varargs"><em>variable argument
+handling intrinsic</em></a> functions.  ‘<tt class="docutils literal"><span class="pre"><returntype></span></tt>‘ is any type
+except <a class="reference internal" href="#t-label"><em>label</em></a> and <a class="reference internal" href="#t-metadata"><em>metadata</em></a>.</p>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Examples:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<table border="1" class="docutils">
+<colgroup>
+<col width="17%" />
+<col width="83%" />
+</colgroup>
+<tbody valign="top">
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">i32</span> <span class="pre">(i32)</span></tt></td>
+<td>function taking an <tt class="docutils literal"><span class="pre">i32</span></tt>, returning an <tt class="docutils literal"><span class="pre">i32</span></tt></td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">float</span> <span class="pre">(i16,</span> <span class="pre">i32</span> <span class="pre">*)</span> <span class="pre">*</span></tt></td>
+<td><a class="reference internal" href="#t-pointer"><em>Pointer</em></a> to a function that takes an <tt class="docutils literal"><span class="pre">i16</span></tt> and a <a class="reference internal" href="#t-pointer"><em>pointer</em></a> to <tt class="docutils literal"><span class="pre">i32</span></tt>, returning <tt class="docutils literal"><span class="pre">float</span></tt>.</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">i32</span> <span class="pre">(i8*,</span> <span class="pre">...)</span></tt></td>
+<td>A vararg function that takes at least one <a class="reference internal" href="#t-pointer"><em>pointer</em></a> to <tt class="docutils literal"><span class="pre">i8</span></tt> (char in C), which returns an integer. This is the signature for <tt class="docutils literal"><span class="pre">printf</span></tt> in LLVM.</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">{i32,</span> <span class="pre">i32}</span> <span class="pre">(i32)</span></tt></td>
+<td>A function taking an <tt class="docutils literal"><span class="pre">i32</span></tt>, returning a <a class="reference internal" href="#t-struct"><em>structure</em></a> containing two <tt class="docutils literal"><span class="pre">i32</span></tt> values</td>
+</tr>
+</tbody>
+</table>
+</div>
+<div class="section" id="first-class-types">
+<span id="t-firstclass"></span><h3><a class="toc-backref" href="#id614">First Class Types</a><a class="headerlink" href="#first-class-types" title="Permalink to this headline">¶</a></h3>
+<p>The <a class="reference internal" href="#t-firstclass"><em>first class</em></a> types are perhaps the most important.
+Values of these types are the only ones which can be produced by
+instructions.</p>
+<div class="section" id="single-value-types">
+<span id="t-single-value"></span><h4><a class="toc-backref" href="#id615">Single Value Types</a><a class="headerlink" href="#single-value-types" title="Permalink to this headline">¶</a></h4>
+<p>These are the types that are valid in registers from CodeGen’s perspective.</p>
+<div class="section" id="integer-type">
+<span id="t-integer"></span><h5><a class="toc-backref" href="#id616">Integer Type</a><a class="headerlink" href="#integer-type" title="Permalink to this headline">¶</a></h5>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Overview:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<p>The integer type is a very simple type that simply specifies an
+arbitrary bit width for the integer type desired. Any bit width from 1
+bit to 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Syntax:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<div class="highlight-python"><div class="highlight"><pre><span class="n">iN</span>
+</pre></div>
+</div>
+<p>The number of bits the integer will occupy is specified by the <tt class="docutils literal"><span class="pre">N</span></tt>
+value.</p>
+<div class="section" id="examples">
+<h6>Examples:<a class="headerlink" href="#examples" title="Permalink to this headline">¶</a></h6>
+<table border="1" class="docutils">
+<colgroup>
+<col width="25%" />
+<col width="75%" />
+</colgroup>
+<tbody valign="top">
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">i1</span></tt></td>
+<td>a single-bit integer.</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">i32</span></tt></td>
+<td>a 32-bit integer.</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">i1942652</span></tt></td>
+<td>a really big integer of over 1 million bits.</td>
+</tr>
+</tbody>
+</table>
+</div>
+</div>
+<div class="section" id="floating-point-types">
+<span id="t-floating"></span><h5><a class="toc-backref" href="#id617">Floating Point Types</a><a class="headerlink" href="#floating-point-types" title="Permalink to this headline">¶</a></h5>
+<table border="1" class="docutils">
+<colgroup>
+<col width="50%" />
+<col width="50%" />
+</colgroup>
+<thead valign="bottom">
+<tr class="row-odd"><th class="head">Type</th>
+<th class="head">Description</th>
+</tr>
+</thead>
+<tbody valign="top">
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">half</span></tt></td>
+<td>16-bit floating point value</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">float</span></tt></td>
+<td>32-bit floating point value</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">double</span></tt></td>
+<td>64-bit floating point value</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">fp128</span></tt></td>
+<td>128-bit floating point value (112-bit mantissa)</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">x86_fp80</span></tt></td>
+<td>80-bit floating point value (X87)</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">ppc_fp128</span></tt></td>
+<td>128-bit floating point value (two 64-bits)</td>
+</tr>
+</tbody>
+</table>
+</div>
+<div class="section" id="x86-mmx-type">
+<h5><a class="toc-backref" href="#id618">X86_mmx Type</a><a class="headerlink" href="#x86-mmx-type" title="Permalink to this headline">¶</a></h5>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Overview:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<p>The x86_mmx type represents a value held in an MMX register on an x86
+machine. The operations allowed on it are quite limited: parameters and
+return values, load and store, and bitcast. User-specified MMX
+instructions are represented as intrinsic or asm calls with arguments
+and/or results of this type. There are no arrays, vectors or constants
+of this type.</p>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Syntax:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<div class="highlight-python"><div class="highlight"><pre><span class="n">x86_mmx</span>
+</pre></div>
+</div>
+</div>
+<div class="section" id="pointer-type">
+<span id="t-pointer"></span><h5><a class="toc-backref" href="#id619">Pointer Type</a><a class="headerlink" href="#pointer-type" title="Permalink to this headline">¶</a></h5>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Overview:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<p>The pointer type is used to specify memory locations. Pointers are
+commonly used to reference objects in memory.</p>
+<p>Pointer types may have an optional address space attribute defining the
+numbered address space where the pointed-to object resides. The default
+address space is number zero. The semantics of non-zero address spaces
+are target-specific.</p>
+<p>Note that LLVM does not permit pointers to void (<tt class="docutils literal"><span class="pre">void*</span></tt>) nor does it
+permit pointers to labels (<tt class="docutils literal"><span class="pre">label*</span></tt>). Use <tt class="docutils literal"><span class="pre">i8*</span></tt> instead.</p>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Syntax:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<div class="highlight-python"><div class="highlight"><pre><type> *
+</pre></div>
+</div>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Examples:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<table border="1" class="docutils">
+<colgroup>
+<col width="19%" />
+<col width="81%" />
+</colgroup>
+<tbody valign="top">
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">[4</span> <span class="pre">x</span> <span class="pre">i32]*</span></tt></td>
+<td>A <a class="reference internal" href="#t-pointer"><em>pointer</em></a> to <a class="reference internal" href="#t-array"><em>array</em></a> of four <tt class="docutils literal"><span class="pre">i32</span></tt> values.</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">i32</span> <span class="pre">(i32*)</span> <span class="pre">*</span></tt></td>
+<td>A <a class="reference internal" href="#t-pointer"><em>pointer</em></a> to a <a class="reference internal" href="#t-function"><em>function</em></a> that takes an <tt class="docutils literal"><span class="pre">i32*</span></tt>, returning an <tt class="docutils literal"><span class="pre">i32</span></tt>.</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">i32</span> <span class="pre">addrspace(5)*</span></tt></td>
+<td>A <a class="reference internal" href="#t-pointer"><em>pointer</em></a> to an <tt class="docutils literal"><span class="pre">i32</span></tt> value that resides in address space #5.</td>
+</tr>
+</tbody>
+</table>
+</div>
+<div class="section" id="vector-type">
+<span id="t-vector"></span><h5><a class="toc-backref" href="#id620">Vector Type</a><a class="headerlink" href="#vector-type" title="Permalink to this headline">¶</a></h5>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Overview:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<p>A vector type is a simple derived type that represents a vector of
+elements. Vector types are used when multiple primitive data are
+operated in parallel using a single instruction (SIMD). A vector type
+requires a size (number of elements) and an underlying primitive data
+type. Vector types are considered <a class="reference internal" href="#t-firstclass"><em>first class</em></a>.</p>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Syntax:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<div class="highlight-python"><div class="highlight"><pre>< <# elements> x <elementtype> >
+</pre></div>
+</div>
+<p>The number of elements is a constant integer value larger than 0;
+elementtype may be any integer, floating point or pointer type. Vectors
+of size zero are not allowed.</p>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Examples:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<table border="1" class="docutils">
+<colgroup>
+<col width="28%" />
+<col width="72%" />
+</colgroup>
+<tbody valign="top">
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre"><4</span> <span class="pre">x</span> <span class="pre">i32></span></tt></td>
+<td>Vector of 4 32-bit integer values.</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre"><8</span> <span class="pre">x</span> <span class="pre">float></span></tt></td>
+<td>Vector of 8 32-bit floating-point values.</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre"><2</span> <span class="pre">x</span> <span class="pre">i64></span></tt></td>
+<td>Vector of 2 64-bit integer values.</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre"><4</span> <span class="pre">x</span> <span class="pre">i64*></span></tt></td>
+<td>Vector of 4 pointers to 64-bit integer values.</td>
+</tr>
+</tbody>
+</table>
+</div>
+</div>
+<div class="section" id="label-type">
+<span id="t-label"></span><h4><a class="toc-backref" href="#id621">Label Type</a><a class="headerlink" href="#label-type" title="Permalink to this headline">¶</a></h4>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Overview:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<p>The label type represents code labels.</p>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Syntax:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<div class="highlight-python"><div class="highlight"><pre><span class="n">label</span>
+</pre></div>
+</div>
+</div>
+<div class="section" id="metadata-type">
+<span id="t-metadata"></span><h4><a class="toc-backref" href="#id622">Metadata Type</a><a class="headerlink" href="#metadata-type" title="Permalink to this headline">¶</a></h4>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Overview:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<p>The metadata type represents embedded metadata. No derived types may be
+created from metadata except for <a class="reference internal" href="#t-function"><em>function</em></a> arguments.</p>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Syntax:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<div class="highlight-python"><div class="highlight"><pre><span class="n">metadata</span>
+</pre></div>
+</div>
+</div>
+<div class="section" id="aggregate-types">
+<span id="t-aggregate"></span><h4><a class="toc-backref" href="#id623">Aggregate Types</a><a class="headerlink" href="#aggregate-types" title="Permalink to this headline">¶</a></h4>
+<p>Aggregate Types are a subset of derived types that can contain multiple
+member types. <a class="reference internal" href="#t-array"><em>Arrays</em></a> and <a class="reference internal" href="#t-struct"><em>structs</em></a> are
+aggregate types. <a class="reference internal" href="#t-vector"><em>Vectors</em></a> are not considered to be
+aggregate types.</p>
+<div class="section" id="array-type">
+<span id="t-array"></span><h5><a class="toc-backref" href="#id624">Array Type</a><a class="headerlink" href="#array-type" title="Permalink to this headline">¶</a></h5>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Overview:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<p>The array type is a very simple derived type that arranges elements
+sequentially in memory. The array type requires a size (number of
+elements) and an underlying data type.</p>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Syntax:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<div class="highlight-python"><div class="highlight"><pre>[<# elements> x <elementtype>]
+</pre></div>
+</div>
+<p>The number of elements is a constant integer value; <tt class="docutils literal"><span class="pre">elementtype</span></tt> may
+be any type with a size.</p>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Examples:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<table border="1" class="docutils">
+<colgroup>
+<col width="32%" />
+<col width="68%" />
+</colgroup>
+<tbody valign="top">
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">[40</span> <span class="pre">x</span> <span class="pre">i32]</span></tt></td>
+<td>Array of 40 32-bit integer values.</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">[41</span> <span class="pre">x</span> <span class="pre">i32]</span></tt></td>
+<td>Array of 41 32-bit integer values.</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">[4</span> <span class="pre">x</span> <span class="pre">i8]</span></tt></td>
+<td>Array of 4 8-bit integer values.</td>
+</tr>
+</tbody>
+</table>
+<p>Here are some examples of multidimensional arrays:</p>
+<table border="1" class="docutils">
+<colgroup>
+<col width="33%" />
+<col width="67%" />
+</colgroup>
+<tbody valign="top">
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">[3</span> <span class="pre">x</span> <span class="pre">[4</span> <span class="pre">x</span> <span class="pre">i32]]</span></tt></td>
+<td>3x4 array of 32-bit integer values.</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">[12</span> <span class="pre">x</span> <span class="pre">[10</span> <span class="pre">x</span> <span class="pre">float]]</span></tt></td>
+<td>12x10 array of single precision floating point values.</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">[2</span> <span class="pre">x</span> <span class="pre">[3</span> <span class="pre">x</span> <span class="pre">[4</span> <span class="pre">x</span> <span class="pre">i16]]]</span></tt></td>
+<td>2x3x4 array of 16-bit integer values.</td>
+</tr>
+</tbody>
+</table>
+<p>There is no restriction on indexing beyond the end of the array implied
+by a static type (though there are restrictions on indexing beyond the
+bounds of an allocated object in some cases). This means that
+single-dimension ‘variable sized array’ addressing can be implemented in
+LLVM with a zero length array type. An implementation of ‘pascal style
+arrays’ in LLVM could use the type “<tt class="docutils literal"><span class="pre">{</span> <span class="pre">i32,</span> <span class="pre">[0</span> <span class="pre">x</span> <span class="pre">float]}</span></tt>”, for
+example.</p>
+</div>
+<div class="section" id="structure-type">
+<span id="t-struct"></span><h5><a class="toc-backref" href="#id625">Structure Type</a><a class="headerlink" href="#structure-type" title="Permalink to this headline">¶</a></h5>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Overview:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<p>The structure type is used to represent a collection of data members
+together in memory. The elements of a structure may be any type that has
+a size.</p>
+<p>Structures in memory are accessed using ‘<tt class="docutils literal"><span class="pre">load</span></tt>‘ and ‘<tt class="docutils literal"><span class="pre">store</span></tt>‘ by
+getting a pointer to a field with the ‘<tt class="docutils literal"><span class="pre">getelementptr</span></tt>‘ instruction.
+Structures in registers are accessed using the ‘<tt class="docutils literal"><span class="pre">extractvalue</span></tt>‘ and
+‘<tt class="docutils literal"><span class="pre">insertvalue</span></tt>‘ instructions.</p>
+<p>Structures may optionally be “packed” structures, which indicate that
+the alignment of the struct is one byte, and that there is no padding
+between the elements. In non-packed structs, padding between field types
+is inserted as defined by the DataLayout string in the module, which is
+required to match what the underlying code generator expects.</p>
+<p>Structures can either be “literal” or “identified”. A literal structure
+is defined inline with other types (e.g. <tt class="docutils literal"><span class="pre">{i32,</span> <span class="pre">i32}*</span></tt>) whereas
+identified types are always defined at the top level with a name.
+Literal types are uniqued by their contents and can never be recursive
+or opaque since there is no way to write one. Identified types can be
+recursive, can be opaqued, and are never uniqued.</p>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Syntax:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<div class="highlight-python"><div class="highlight"><pre>%T1 = type { <type list> }     ; Identified normal struct type
+%T2 = type <{ <type list> }>   ; Identified packed struct type
+</pre></div>
+</div>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Examples:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<table border="1" class="docutils">
+<colgroup>
+<col width="14%" />
+<col width="86%" />
+</colgroup>
+<tbody valign="top">
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">{</span> <span class="pre">i32,</span> <span class="pre">i32,</span> <span class="pre">i32</span> <span class="pre">}</span></tt></td>
+<td>A triple of three <tt class="docutils literal"><span class="pre">i32</span></tt> values</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">{</span> <span class="pre">float,</span> <span class="pre">i32</span> <span class="pre">(i32)</span> <span class="pre">*</span> <span class="pre">}</span></tt></td>
+<td>A pair, where the first element is a <tt class="docutils literal"><span class="pre">float</span></tt> and the second element is a <a class="reference internal" href="#t-pointer"><em>pointer</em></a> to a <a class="reference internal" href="#t-function"><em>function</em></a> that takes an <tt class="docutils literal"><span class="pre">i32</span></tt>, returning an <tt class="docutils literal"><span class="pre">i32</span></tt>.</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre"><{</span> <span class="pre">i8,</span> <span class="pre">i32</span> <span class="pre">}></span></tt></td>
+<td>A packed struct known to be 5 bytes in size.</td>
+</tr>
+</tbody>
+</table>
+</div>
+<div class="section" id="opaque-structure-types">
+<span id="t-opaque"></span><h5><a class="toc-backref" href="#id626">Opaque Structure Types</a><a class="headerlink" href="#opaque-structure-types" title="Permalink to this headline">¶</a></h5>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Overview:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<p>Opaque structure types are used to represent named structure types that
+do not have a body specified. This corresponds (for example) to the C
+notion of a forward declared structure.</p>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Syntax:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<div class="highlight-python"><div class="highlight"><pre>%X = type opaque
+%52 = type opaque
+</pre></div>
+</div>
+<table class="docutils field-list" frame="void" rules="none">
+<col class="field-name" />
+<col class="field-body" />
+<tbody valign="top">
+<tr class="field-odd field"><th class="field-name">Examples:</th><td class="field-body"></td>
+</tr>
+</tbody>
+</table>
+<table border="1" class="docutils">
+<colgroup>
+<col width="42%" />
+<col width="58%" />
+</colgroup>
+<tbody valign="top">
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">opaque</span></tt></td>
+<td>An opaque type.</td>
+</tr>
+</tbody>
+</table>
+</div>
+</div>
+</div>
+</div>
+<div class="section" id="constants">
+<span id="id3"></span><h2><a class="toc-backref" href="#id627">Constants</a><a class="headerlink" href="#constants" title="Permalink to this headline">¶</a></h2>
+<p>LLVM has several different basic types of constants. This section
+describes them all and their syntax.</p>
+<div class="section" id="simple-constants">
+<h3><a class="toc-backref" href="#id628">Simple Constants</a><a class="headerlink" href="#simple-constants" title="Permalink to this headline">¶</a></h3>
+<dl class="docutils">
+<dt><strong>Boolean constants</strong></dt>
+<dd>The two strings ‘<tt class="docutils literal"><span class="pre">true</span></tt>‘ and ‘<tt class="docutils literal"><span class="pre">false</span></tt>‘ are both valid constants
+of the <tt class="docutils literal"><span class="pre">i1</span></tt> type.</dd>
+<dt><strong>Integer constants</strong></dt>
+<dd>Standard integers (such as ‘4’) are constants of the
+<a class="reference internal" href="#t-integer"><em>integer</em></a> type. Negative numbers may be used with
+integer types.</dd>
+<dt><strong>Floating point constants</strong></dt>
+<dd>Floating point constants use standard decimal notation (e.g.
+123.421), exponential notation (e.g. 1.23421e+2), or a more precise
+hexadecimal notation (see below). The assembler requires the exact
+decimal value of a floating-point constant. For example, the
+assembler accepts 1.25 but rejects 1.3 because 1.3 is a repeating
+decimal in binary. Floating point constants must have a <a class="reference internal" href="#t-floating"><em>floating
+point</em></a> type.</dd>
+<dt><strong>Null pointer constants</strong></dt>
+<dd>The identifier ‘<tt class="docutils literal"><span class="pre">null</span></tt>‘ is recognized as a null pointer constant
+and must be of <a class="reference internal" href="#t-pointer"><em>pointer type</em></a>.</dd>
+</dl>
+<p>The one non-intuitive notation for constants is the hexadecimal form of
+floating point constants. For example, the form
+‘<tt class="docutils literal"><span class="pre">double</span>    <span class="pre">0x432ff973cafa8000</span></tt>‘ is equivalent to (but harder to read
+than) ‘<tt class="docutils literal"><span class="pre">double</span> <span class="pre">4.5e+15</span></tt>‘. The only time hexadecimal floating point
+constants are required (and the only time that they are generated by the
+disassembler) is when a floating point constant must be emitted but it
+cannot be represented as a decimal floating point number in a reasonable
+number of digits. For example, NaN’s, infinities, and other special
+values are represented in their IEEE hexadecimal format so that assembly
+and disassembly do not cause any bits to change in the constants.</p>
+<p>When using the hexadecimal form, constants of types half, float, and
+double are represented using the 16-digit form shown above (which
+matches the IEEE754 representation for double); half and float values
+must, however, be exactly representable as IEEE 754 half and single
+precision, respectively. Hexadecimal format is always used for long
+double, and there are three forms of long double. The 80-bit format used
+by x86 is represented as <tt class="docutils literal"><span class="pre">0xK</span></tt> followed by 20 hexadecimal digits. The
+128-bit format used by PowerPC (two adjacent doubles) is represented by
+<tt class="docutils literal"><span class="pre">0xM</span></tt> followed by 32 hexadecimal digits. The IEEE 128-bit format is
+represented by <tt class="docutils literal"><span class="pre">0xL</span></tt> followed by 32 hexadecimal digits. Long doubles
+will only work if they match the long double format on your target.
+The IEEE 16-bit format (half precision) is represented by <tt class="docutils literal"><span class="pre">0xH</span></tt>
+followed by 4 hexadecimal digits. All hexadecimal formats are big-endian
+(sign bit at the left).</p>
+<p>There are no constants of type x86_mmx.</p>
+</div>
+<div class="section" id="complex-constants">
+<span id="complexconstants"></span><h3><a class="toc-backref" href="#id629">Complex Constants</a><a class="headerlink" href="#complex-constants" title="Permalink to this headline">¶</a></h3>
+<p>Complex constants are a (potentially recursive) combination of simple
+constants and smaller complex constants.</p>
+<dl class="docutils">
+<dt><strong>Structure constants</strong></dt>
+<dd>Structure constants are represented with notation similar to
+structure type definitions (a comma separated list of elements,
+surrounded by braces (<tt class="docutils literal"><span class="pre">{}</span></tt>)). For example:
+“<tt class="docutils literal"><span class="pre">{</span> <span class="pre">i32</span> <span class="pre">4,</span> <span class="pre">float</span> <span class="pre">17.0,</span> <span class="pre">i32*</span> <span class="pre">@G</span> <span class="pre">}</span></tt>”, where “<tt class="docutils literal"><span class="pre">@G</span></tt>” is declared as
+“<tt class="docutils literal"><span class="pre">@G</span> <span class="pre">=</span> <span class="pre">external</span> <span class="pre">global</span> <span class="pre">i32</span></tt>”. Structure constants must have
+<a class="reference internal" href="#t-struct"><em>structure type</em></a>, and the number and types of elements
+must match those specified by the type.</dd>
+<dt><strong>Array constants</strong></dt>
+<dd>Array constants are represented with notation similar to array type
+definitions (a comma separated list of elements, surrounded by
+square brackets (<tt class="docutils literal"><span class="pre">[]</span></tt>)). For example:
+“<tt class="docutils literal"><span class="pre">[</span> <span class="pre">i32</span> <span class="pre">42,</span> <span class="pre">i32</span> <span class="pre">11,</span> <span class="pre">i32</span> <span class="pre">74</span> <span class="pre">]</span></tt>”. Array constants must have
+<a class="reference internal" href="#t-array"><em>array type</em></a>, and the number and types of elements must
+match those specified by the type. As a special case, character array
+constants may also be represented as a double-quoted string using the <tt class="docutils literal"><span class="pre">c</span></tt>
+prefix. For example: “<tt class="docutils literal"><span class="pre">c"Hello</span> <span class="pre">World\0A\00"</span></tt>”.</dd>
+<dt><strong>Vector constants</strong></dt>
+<dd>Vector constants are represented with notation similar to vector
+type definitions (a comma separated list of elements, surrounded by
+less-than/greater-than’s (<tt class="docutils literal"><span class="pre"><></span></tt>)). For example:
+“<tt class="docutils literal"><span class="pre"><</span> <span class="pre">i32</span> <span class="pre">42,</span> <span class="pre">i32</span> <span class="pre">11,</span> <span class="pre">i32</span> <span class="pre">74,</span> <span class="pre">i32</span> <span class="pre">100</span> <span class="pre">></span></tt>”. Vector constants
+must have <a class="reference internal" href="#t-vector"><em>vector type</em></a>, and the number and types of
+elements must match those specified by the type.</dd>
+<dt><strong>Zero initialization</strong></dt>
+<dd>The string ‘<tt class="docutils literal"><span class="pre">zeroinitializer</span></tt>‘ can be used to zero initialize a
+value to zero of <em>any</em> type, including scalar and
+<a class="reference internal" href="#t-aggregate"><em>aggregate</em></a> types. This is often used to avoid
+having to print large zero initializers (e.g. for large arrays) and
+is always exactly equivalent to using explicit zero initializers.</dd>
+<dt><strong>Metadata node</strong></dt>
+<dd>A metadata node is a constant tuple without types.  For example:
+“<tt class="docutils literal"><span class="pre">!{!0,</span> <span class="pre">!{!2,</span> <span class="pre">!0},</span> <span class="pre">!"test"}</span></tt>”.  Metadata can reference constant values,
+for example: “<tt class="docutils literal"><span class="pre">!{!0,</span> <span class="pre">i32</span> <span class="pre">0,</span> <span class="pre">i8*</span> <span class="pre">@global,</span> <span class="pre">i64</span> <span class="pre">(i64)*</span> <span class="pre">@function,</span> <span class="pre">!"str"}</span></tt>”.
+Unlike other typed constants that are meant to be interpreted as part of
+the instruction stream, metadata is a place to attach additional
+information such as debug info.</dd>
+</dl>
+</div>
+<div class="section" id="global-variable-and-function-addresses">
+<h3><a class="toc-backref" href="#id630">Global Variable and Function Addresses</a><a class="headerlink" href="#global-variable-and-function-addresses" title="Permalink to this headline">¶</a></h3>
+<p>The addresses of <a class="reference internal" href="#globalvars"><em>global variables</em></a> and
+<a class="reference internal" href="#functionstructure"><em>functions</em></a> are always implicitly valid
+(link-time) constants. These constants are explicitly referenced when
+the <a class="reference internal" href="#identifiers"><em>identifier for the global</em></a> is used and always have
+<a class="reference internal" href="#t-pointer"><em>pointer</em></a> type. For example, the following is a legal LLVM
+file:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="vg">@X</span> <span class="p">=</span> <span class="k">global</span> <span class="k">i32</span> <span class="m">17</span>
+<span class="vg">@Y</span> <span class="p">=</span> <span class="k">global</span> <span class="k">i32</span> <span class="m">42</span>
+<span class="vg">@Z</span> <span class="p">=</span> <span class="k">global</span> <span class="p">[</span><span class="m">2</span> <span class="k">x</span> <span class="k">i32</span><span class="p">*]</span> <span class="p">[</span> <span class="k">i32</span><span class="p">*</span> <span class="vg">@X</span><span class="p">,</span> <span class="k">i32</span><span class="p">*</span> <span class="vg">@Y</span> <span class="p">]</span>
+</pre></div>
+</div>
+</div>
+<div class="section" id="undefined-values">
+<span id="undefvalues"></span><h3><a class="toc-backref" href="#id631">Undefined Values</a><a class="headerlink" href="#undefined-values" title="Permalink to this headline">¶</a></h3>
+<p>The string ‘<tt class="docutils literal"><span class="pre">undef</span></tt>‘ can be used anywhere a constant is expected, and
+indicates that the user of the value may receive an unspecified
+bit-pattern. Undefined values may be of any type (other than ‘<tt class="docutils literal"><span class="pre">label</span></tt>‘
+or ‘<tt class="docutils literal"><span class="pre">void</span></tt>‘) and be used anywhere a constant is permitted.</p>
+<p>Undefined values are useful because they indicate to the compiler that
+the program is well defined no matter what value is used. This gives the
+compiler more freedom to optimize. Here are some examples of
+(potentially surprising) transformations that are valid (in pseudo IR):</p>
+<div class="highlight-llvm"><div class="highlight"><pre>  <span class="nv">%A</span> <span class="p">=</span> <span class="k">add</span> <span class="nv">%X</span><span class="p">,</span> <span class="k">undef</span>
+  <span class="nv">%B</span> <span class="p">=</span> <span class="k">sub</span> <span class="nv">%X</span><span class="p">,</span> <span class="k">undef</span>
+  <span class="nv">%C</span> <span class="p">=</span> <span class="k">xor</span> <span class="nv">%X</span><span class="p">,</span> <span class="k">undef</span>
+<span class="nl">Safe:</span>
+  <span class="nv">%A</span> <span class="p">=</span> <span class="k">undef</span>
+  <span class="nv">%B</span> <span class="p">=</span> <span class="k">undef</span>
+  <span class="nv">%C</span> <span class="p">=</span> <span class="k">undef</span>
+</pre></div>
+</div>
+<p>This is safe because all of the output bits are affected by the undef
+bits. Any output bit can have a zero or one depending on the input bits.</p>
+<div class="highlight-llvm"><div class="highlight"><pre>  <span class="nv">%A</span> <span class="p">=</span> <span class="k">or</span> <span class="nv">%X</span><span class="p">,</span> <span class="k">undef</span>
+  <span class="nv">%B</span> <span class="p">=</span> <span class="k">and</span> <span class="nv">%X</span><span class="p">,</span> <span class="k">undef</span>
+<span class="nl">Safe:</span>
+  <span class="nv">%A</span> <span class="p">=</span> <span class="m">-1</span>
+  <span class="nv">%B</span> <span class="p">=</span> <span class="m">0</span>
+<span class="nl">Unsafe:</span>
+  <span class="nv">%A</span> <span class="p">=</span> <span class="k">undef</span>
+  <span class="nv">%B</span> <span class="p">=</span> <span class="k">undef</span>
+</pre></div>
+</div>
+<p>These logical operations have bits that are not always affected by the
+input. For example, if <tt class="docutils literal"><span class="pre">%X</span></tt> has a zero bit, then the output of the
+‘<tt class="docutils literal"><span class="pre">and</span></tt>‘ operation will always be a zero for that bit, no matter what
+the corresponding bit from the ‘<tt class="docutils literal"><span class="pre">undef</span></tt>‘ is. As such, it is unsafe to
+optimize or assume that the result of the ‘<tt class="docutils literal"><span class="pre">and</span></tt>‘ is ‘<tt class="docutils literal"><span class="pre">undef</span></tt>‘.
+However, it is safe to assume that all bits of the ‘<tt class="docutils literal"><span class="pre">undef</span></tt>‘ could be
+0, and optimize the ‘<tt class="docutils literal"><span class="pre">and</span></tt>‘ to 0. Likewise, it is safe to assume that
+all the bits of the ‘<tt class="docutils literal"><span class="pre">undef</span></tt>‘ operand to the ‘<tt class="docutils literal"><span class="pre">or</span></tt>‘ could be set,
+allowing the ‘<tt class="docutils literal"><span class="pre">or</span></tt>‘ to be folded to -1.</p>
+<div class="highlight-llvm"><div class="highlight"><pre>  <span class="nv">%A</span> <span class="p">=</span> <span class="k">select</span> <span class="k">undef</span><span class="p">,</span> <span class="nv">%X</span><span class="p">,</span> <span class="nv">%Y</span>
+  <span class="nv">%B</span> <span class="p">=</span> <span class="k">select</span> <span class="k">undef</span><span class="p">,</span> <span class="m">42</span><span class="p">,</span> <span class="nv">%Y</span>
+  <span class="nv">%C</span> <span class="p">=</span> <span class="k">select</span> <span class="nv">%X</span><span class="p">,</span> <span class="nv">%Y</span><span class="p">,</span> <span class="k">undef</span>
+<span class="nl">Safe:</span>
+  <span class="nv">%A</span> <span class="p">=</span> <span class="nv">%X</span>     <span class="p">(</span><span class="k">or</span> <span class="nv">%Y</span><span class="p">)</span>
+  <span class="nv">%B</span> <span class="p">=</span> <span class="m">42</span>     <span class="p">(</span><span class="k">or</span> <span class="nv">%Y</span><span class="p">)</span>
+  <span class="nv">%C</span> <span class="p">=</span> <span class="nv">%Y</span>
+<span class="nl">Unsafe:</span>
+  <span class="nv">%A</span> <span class="p">=</span> <span class="k">undef</span>
+  <span class="nv">%B</span> <span class="p">=</span> <span class="k">undef</span>
+  <span class="nv">%C</span> <span class="p">=</span> <span class="k">undef</span>
+</pre></div>
+</div>
+<p>This set of examples shows that undefined ‘<tt class="docutils literal"><span class="pre">select</span></tt>‘ (and conditional
+branch) conditions can go <em>either way</em>, but they have to come from one
+of the two operands. In the <tt class="docutils literal"><span class="pre">%A</span></tt> example, if <tt class="docutils literal"><span class="pre">%X</span></tt> and <tt class="docutils literal"><span class="pre">%Y</span></tt> were
+both known to have a clear low bit, then <tt class="docutils literal"><span class="pre">%A</span></tt> would have to have a
+cleared low bit. However, in the <tt class="docutils literal"><span class="pre">%C</span></tt> example, the optimizer is
+allowed to assume that the ‘<tt class="docutils literal"><span class="pre">undef</span></tt>‘ operand could be the same as
+<tt class="docutils literal"><span class="pre">%Y</span></tt>, allowing the whole ‘<tt class="docutils literal"><span class="pre">select</span></tt>‘ to be eliminated.</p>
+<div class="highlight-llvm"><div class="highlight"><pre>  %A = xor undef, undef
+
+  %B = undef
+  %C = xor %B, %B
+
+  %D = undef
+  %E = icmp slt %D, 4
+  %F = icmp gte %D, 4
+
+Safe:
+  %A = undef
+  %B = undef
+  %C = undef
+  %D = undef
+  %E = undef
+  %F = undef
+</pre></div>
+</div>
+<p>This example points out that two ‘<tt class="docutils literal"><span class="pre">undef</span></tt>‘ operands are not
+necessarily the same. This can be surprising to people (and also matches
+C semantics) where they assume that “<tt class="docutils literal"><span class="pre">X^X</span></tt>” is always zero, even if
+<tt class="docutils literal"><span class="pre">X</span></tt> is undefined. This isn’t true for a number of reasons, but the
+short answer is that an ‘<tt class="docutils literal"><span class="pre">undef</span></tt>‘ “variable” can arbitrarily change
+its value over its “live range”. This is true because the variable
+doesn’t actually <em>have a live range</em>. Instead, the value is logically
+read from arbitrary registers that happen to be around when needed, so
+the value is not necessarily consistent over time. In fact, <tt class="docutils literal"><span class="pre">%A</span></tt> and
+<tt class="docutils literal"><span class="pre">%C</span></tt> need to have the same semantics or the core LLVM “replace all
+uses with” concept would not hold.</p>
+<div class="highlight-llvm"><div class="highlight"><pre>  <span class="nv">%A</span> <span class="p">=</span> <span class="k">fdiv</span> <span class="k">undef</span><span class="p">,</span> <span class="nv">%X</span>
+  <span class="nv">%B</span> <span class="p">=</span> <span class="k">fdiv</span> <span class="nv">%X</span><span class="p">,</span> <span class="k">undef</span>
+<span class="nl">Safe:</span>
+  <span class="nv">%A</span> <span class="p">=</span> <span class="k">undef</span>
+<span class="nl">b:</span> <span class="k">unreachable</span>
+</pre></div>
+</div>
+<p>These examples show the crucial difference between an <em>undefined value</em>
+and <em>undefined behavior</em>. An undefined value (like ‘<tt class="docutils literal"><span class="pre">undef</span></tt>‘) is
+allowed to have an arbitrary bit-pattern. This means that the <tt class="docutils literal"><span class="pre">%A</span></tt>
+operation can be constant folded to ‘<tt class="docutils literal"><span class="pre">undef</span></tt>‘, because the ‘<tt class="docutils literal"><span class="pre">undef</span></tt>‘
+could be an SNaN, and <tt class="docutils literal"><span class="pre">fdiv</span></tt> is not (currently) defined on SNaN’s.
+However, in the second example, we can make a more aggressive
+assumption: because the <tt class="docutils literal"><span class="pre">undef</span></tt> is allowed to be an arbitrary value,
+we are allowed to assume that it could be zero. Since a divide by zero
+has <em>undefined behavior</em>, we are allowed to assume that the operation
+does not execute at all. This allows us to delete the divide and all
+code after it. Because the undefined operation “can’t happen”, the
+optimizer can assume that it occurs in dead code.</p>
+<div class="highlight-llvm"><div class="highlight"><pre>a:  store undef -> %X
+b:  store %X -> undef
+Safe:
+a: <deleted>
+b: unreachable
+</pre></div>
+</div>
+<p>These examples reiterate the <tt class="docutils literal"><span class="pre">fdiv</span></tt> example: a store <em>of</em> an undefined
+value can be assumed to not have any effect; we can assume that the
+value is overwritten with bits that happen to match what was already
+there. However, a store <em>to</em> an undefined location could clobber
+arbitrary memory, therefore, it has undefined behavior.</p>
+</div>
+<div class="section" id="poison-values">
+<span id="poisonvalues"></span><h3><a class="toc-backref" href="#id632">Poison Values</a><a class="headerlink" href="#poison-values" title="Permalink to this headline">¶</a></h3>
+<p>Poison values are similar to <a class="reference internal" href="#undefvalues"><em>undef values</em></a>, however
+they also represent the fact that an instruction or constant expression
+that cannot evoke side effects has nevertheless detected a condition
+that results in undefined behavior.</p>
+<p>There is currently no way of representing a poison value in the IR; they
+only exist when produced by operations such as <a class="reference internal" href="#i-add"><em>add</em></a> with
+the <tt class="docutils literal"><span class="pre">nsw</span></tt> flag.</p>
+<p>Poison value behavior is defined in terms of value <em>dependence</em>:</p>
+<ul class="simple">
+<li>Values other than <a class="reference internal" href="#i-phi"><em>phi</em></a> nodes depend on their operands.</li>
+<li><a class="reference internal" href="#i-phi"><em>Phi</em></a> nodes depend on the operand corresponding to
+their dynamic predecessor basic block.</li>
+<li>Function arguments depend on the corresponding actual argument values
+in the dynamic callers of their functions.</li>
+<li><a class="reference internal" href="#i-call"><em>Call</em></a> instructions depend on the <a class="reference internal" href="#i-ret"><em>ret</em></a>
+instructions that dynamically transfer control back to them.</li>
+<li><a class="reference internal" href="#i-invoke"><em>Invoke</em></a> instructions depend on the
+<a class="reference internal" href="#i-ret"><em>ret</em></a>, <a class="reference internal" href="#i-resume"><em>resume</em></a>, or exception-throwing
+call instructions that dynamically transfer control back to them.</li>
+<li>Non-volatile loads and stores depend on the most recent stores to all
+of the referenced memory addresses, following the order in the IR
+(including loads and stores implied by intrinsics such as
+<a class="reference internal" href="#int-memcpy"><em>@llvm.memcpy</em></a>.)</li>
+<li>An instruction with externally visible side effects depends on the
+most recent preceding instruction with externally visible side
+effects, following the order in the IR. (This includes <a class="reference internal" href="#volatile"><em>volatile
+operations</em></a>.)</li>
+<li>An instruction <em>control-depends</em> on a <a class="reference internal" href="#terminators"><em>terminator
+instruction</em></a> if the terminator instruction has
+multiple successors and the instruction is always executed when
+control transfers to one of the successors, and may not be executed
+when control is transferred to another.</li>
+<li>Additionally, an instruction also <em>control-depends</em> on a terminator
+instruction if the set of instructions it otherwise depends on would
+be different if the terminator had transferred control to a different
+successor.</li>
+<li>Dependence is transitive.</li>
+</ul>
+<p>Poison values have the same behavior as <a class="reference internal" href="#undefvalues"><em>undef values</em></a>,
+with the additional effect that any instruction that has a <em>dependence</em>
+on a poison value has undefined behavior.</p>
+<p>Here are some examples:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nl">entry:</span>
+  <span class="nv">%poison</span> <span class="p">=</span> <span class="k">sub</span> <span class="k">nuw</span> <span class="k">i32</span> <span class="m">0</span><span class="p">,</span> <span class="m">1</span>           <span class="c">; Results in a poison value.</span>
+  <span class="nv">%still_poison</span> <span class="p">=</span> <span class="k">and</span> <span class="k">i32</span> <span class="nv">%poison</span><span class="p">,</span> <span class="m">0</span>   <span class="c">; 0, but also poison.</span>
+  <span class="nv">%poison_yet_again</span> <span class="p">=</span> <span class="k">getelementptr</span> <span class="k">i32</span><span class="p">*</span> <span class="vg">@h</span><span class="p">,</span> <span class="k">i32</span> <span class="nv">%still_poison</span>
+  <span class="k">store</span> <span class="k">i32</span> <span class="m">0</span><span class="p">,</span> <span class="k">i32</span><span class="p">*</span> <span class="nv">%poison_yet_again</span>  <span class="c">; memory at @h[0] is poisoned</span>
+
+  <span class="k">store</span> <span class="k">i32</span> <span class="nv">%poison</span><span class="p">,</span> <span class="k">i32</span><span class="p">*</span> <span class="vg">@g</span>           <span class="c">; Poison value stored to memory.</span>
+  <span class="nv">%poison2</span> <span class="p">=</span> <span class="k">load</span> <span class="k">i32</span><span class="p">*</span> <span class="vg">@g</span>              <span class="c">; Poison value loaded back from memory.</span>
+
+  <span class="k">store</span> <span class="k">volatile</span> <span class="k">i32</span> <span class="nv">%poison</span><span class="p">,</span> <span class="k">i32</span><span class="p">*</span> <span class="vg">@g</span>  <span class="c">; External observation; undefined behavior.</span>
+
+  <span class="nv">%narrowaddr</span> <span class="p">=</span> <span class="k">bitcast</span> <span class="k">i32</span><span class="p">*</span> <span class="vg">@g</span> <span class="k">to</span> <span class="k">i16</span><span class="p">*</span>
+  <span class="nv">%wideaddr</span> <span class="p">=</span> <span class="k">bitcast</span> <span class="k">i32</span><span class="p">*</span> <span class="vg">@g</span> <span class="k">to</span> <span class="k">i64</span><span class="p">*</span>
+  <span class="nv">%poison3</span> <span class="p">=</span> <span class="k">load</span> <span class="k">i16</span><span class="p">*</span> <span class="nv">%narrowaddr</span>     <span class="c">; Returns a poison value.</span>
+  <span class="nv">%poison4</span> <span class="p">=</span> <span class="k">load</span> <span class="k">i64</span><span class="p">*</span> <span class="nv">%wideaddr</span>       <span class="c">; Returns a poison value.</span>
+
+  <span class="nv">%cmp</span> <span class="p">=</span> <span class="k">icmp</span> <span class="k">slt</span> <span class="k">i32</span> <span class="nv">%poison</span><span class="p">,</span> <span class="m">0</span>       <span class="c">; Returns a poison value.</span>
+  <span class="k">br</span> <span class="k">i1</span> <span class="nv">%cmp</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%true</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%end</span>  <span class="c">; Branch to either destination.</span>
+
+<span class="nl">true:</span>
+  <span class="k">store</span> <span class="k">volatile</span> <span class="k">i32</span> <span class="m">0</span><span class="p">,</span> <span class="k">i32</span><span class="p">*</span> <span class="vg">@g</span>        <span class="c">; This is control-dependent on %cmp, so</span>
+                                       <span class="c">; it has undefined behavior.</span>
+  <span class="k">br</span> <span class="kt">label</span> <span class="nv">%end</span>
+
+<span class="nl">end:</span>
+  <span class="nv">%p</span> <span class="p">=</span> <span class="k">phi</span> <span class="k">i32</span> <span class="p">[</span> <span class="m">0</span><span class="p">,</span> <span class="nv">%entry</span> <span class="p">],</span> <span class="p">[</span> <span class="m">1</span><span class="p">,</span> <span class="nv">%true</span> <span class="p">]</span>
+                                       <span class="c">; Both edges into this PHI are</span>
+                                       <span class="c">; control-dependent on %cmp, so this</span>
+                                       <span class="c">; always results in a poison value.</span>
+
+  <span class="k">store</span> <span class="k">volatile</span> <span class="k">i32</span> <span class="m">0</span><span class="p">,</span> <span class="k">i32</span><span class="p">*</span> <span class="vg">@g</span>        <span class="c">; This would depend on the store in %true</span>
+                                       <span class="c">; if %cmp is true, or the store in %entry</span>
+                                       <span class="c">; otherwise, so this is undefined behavior.</span>
+
+  <span class="k">br</span> <span class="k">i1</span> <span class="nv">%cmp</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%second_true</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%second_end</span>
+                                       <span class="c">; The same branch again, but this time the</span>
+                                       <span class="c">; true block doesn't have side effects.</span>
+
+<span class="nl">second_true:</span>
+  <span class="c">; No side effects!</span>
+  <span class="k">ret</span> <span class="kt">void</span>
+
+<span class="nl">second_end:</span>
+  <span class="k">store</span> <span class="k">volatile</span> <span class="k">i32</span> <span class="m">0</span><span class="p">,</span> <span class="k">i32</span><span class="p">*</span> <span class="vg">@g</span>        <span class="c">; This time, the instruction always depends</span>
+                                       <span class="c">; on the store in %end. Also, it is</span>
+                                       <span class="c">; control-equivalent to %end, so this is</span>
+                                       <span class="c">; well-defined (ignoring earlier undefined</span>
+                                       <span class="c">; behavior in this example).</span>
+</pre></div>
+</div>
+</div>
+<div class="section" id="addresses-of-basic-blocks">
+<span id="blockaddress"></span><h3><a class="toc-backref" href="#id633">Addresses of Basic Blocks</a><a class="headerlink" href="#addresses-of-basic-blocks" title="Permalink to this headline">¶</a></h3>
+<p><tt class="docutils literal"><span class="pre">blockaddress(@function,</span> <span class="pre">%block)</span></tt></p>
+<p>The ‘<tt class="docutils literal"><span class="pre">blockaddress</span></tt>‘ constant computes the address of the specified
+basic block in the specified function, and always has an <tt class="docutils literal"><span class="pre">i8*</span></tt> type.
+Taking the address of the entry block is illegal.</p>
+<p>This value only has defined behavior when used as an operand to the
+‘<a class="reference internal" href="#i-indirectbr"><em>indirectbr</em></a>‘ instruction, or for comparisons
+against null. Pointer equality tests between labels addresses results in
+undefined behavior — though, again, comparison against null is ok, and
+no label is equal to the null pointer. This may be passed around as an
+opaque pointer sized value as long as the bits are not inspected. This
+allows <tt class="docutils literal"><span class="pre">ptrtoint</span></tt> and arithmetic to be performed on these values so
+long as the original value is reconstituted before the <tt class="docutils literal"><span class="pre">indirectbr</span></tt>
+instruction.</p>
+<p>Finally, some targets may provide defined semantics when using the value
+as the operand to an inline assembly, but that is target specific.</p>
+</div>
+<div class="section" id="constant-expressions">
+<span id="constantexprs"></span><h3><a class="toc-backref" href="#id634">Constant Expressions</a><a class="headerlink" href="#constant-expressions" title="Permalink to this headline">¶</a></h3>
+<p>Constant expressions are used to allow expressions involving other
+constants to be used as constants. Constant expressions may be of any
+<a class="reference internal" href="#t-firstclass"><em>first class</em></a> type and may involve any LLVM operation
+that does not have side effects (e.g. load and call are not supported).
+The following is the syntax for constant expressions:</p>
+<dl class="docutils">
+<dt><tt class="docutils literal"><span class="pre">trunc</span> <span class="pre">(CST</span> <span class="pre">to</span> <span class="pre">TYPE)</span></tt></dt>
+<dd>Truncate a constant to another type. The bit size of CST must be
+larger than the bit size of TYPE. Both types must be integers.</dd>
+<dt><tt class="docutils literal"><span class="pre">zext</span> <span class="pre">(CST</span> <span class="pre">to</span> <span class="pre">TYPE)</span></tt></dt>
+<dd>Zero extend a constant to another type. The bit size of CST must be
+smaller than the bit size of TYPE. Both types must be integers.</dd>
+<dt><tt class="docutils literal"><span class="pre">sext</span> <span class="pre">(CST</span> <span class="pre">to</span> <span class="pre">TYPE)</span></tt></dt>
+<dd>Sign extend a constant to another type. The bit size of CST must be
+smaller than the bit size of TYPE. Both types must be integers.</dd>
+<dt><tt class="docutils literal"><span class="pre">fptrunc</span> <span class="pre">(CST</span> <span class="pre">to</span> <span class="pre">TYPE)</span></tt></dt>
+<dd>Truncate a floating point constant to another floating point type.
+The size of CST must be larger than the size of TYPE. Both types
+must be floating point.</dd>
+<dt><tt class="docutils literal"><span class="pre">fpext</span> <span class="pre">(CST</span> <span class="pre">to</span> <span class="pre">TYPE)</span></tt></dt>
+<dd>Floating point extend a constant to another type. The size of CST
+must be smaller or equal to the size of TYPE. Both types must be
+floating point.</dd>
+<dt><tt class="docutils literal"><span class="pre">fptoui</span> <span class="pre">(CST</span> <span class="pre">to</span> <span class="pre">TYPE)</span></tt></dt>
+<dd>Convert a floating point constant to the corresponding unsigned
+integer constant. TYPE must be a scalar or vector integer type. CST
+must be of scalar or vector floating point type. Both CST and TYPE
+must be scalars, or vectors of the same number of elements. If the
+value won’t fit in the integer type, the results are undefined.</dd>
+<dt><tt class="docutils literal"><span class="pre">fptosi</span> <span class="pre">(CST</span> <span class="pre">to</span> <span class="pre">TYPE)</span></tt></dt>
+<dd>Convert a floating point constant to the corresponding signed
+integer constant. TYPE must be a scalar or vector integer type. CST
+must be of scalar or vector floating point type. Both CST and TYPE
+must be scalars, or vectors of the same number of elements. If the
+value won’t fit in the integer type, the results are undefined.</dd>
+<dt><tt class="docutils literal"><span class="pre">uitofp</span> <span class="pre">(CST</span> <span class="pre">to</span> <span class="pre">TYPE)</span></tt></dt>
+<dd>Convert an unsigned integer constant to the corresponding floating
+point constant. TYPE must be a scalar or vector floating point type.
+CST must be of scalar or vector integer type. Both CST and TYPE must
+be scalars, or vectors of the same number of elements. If the value
+won’t fit in the floating point type, the results are undefined.</dd>
+<dt><tt class="docutils literal"><span class="pre">sitofp</span> <span class="pre">(CST</span> <span class="pre">to</span> <span class="pre">TYPE)</span></tt></dt>
+<dd>Convert a signed integer constant to the corresponding floating
+point constant. TYPE must be a scalar or vector floating point type.
+CST must be of scalar or vector integer type. Both CST and TYPE must
+be scalars, or vectors of the same number of elements. If the value
+won’t fit in the floating point type, the results are undefined.</dd>
+<dt><tt class="docutils literal"><span class="pre">ptrtoint</span> <span class="pre">(CST</span> <span class="pre">to</span> <span class="pre">TYPE)</span></tt></dt>
+<dd>Convert a pointer typed constant to the corresponding integer
+constant. <tt class="docutils literal"><span class="pre">TYPE</span></tt> must be an integer type. <tt class="docutils literal"><span class="pre">CST</span></tt> must be of
+pointer type. The <tt class="docutils literal"><span class="pre">CST</span></tt> value is zero extended, truncated, or
+unchanged to make it fit in <tt class="docutils literal"><span class="pre">TYPE</span></tt>.</dd>
+<dt><tt class="docutils literal"><span class="pre">inttoptr</span> <span class="pre">(CST</span> <span class="pre">to</span> <span class="pre">TYPE)</span></tt></dt>
+<dd>Convert an integer constant to a pointer constant. TYPE must be a
+pointer type. CST must be of integer type. The CST value is zero
+extended, truncated, or unchanged to make it fit in a pointer size.
+This one is <em>really</em> dangerous!</dd>
+<dt><tt class="docutils literal"><span class="pre">bitcast</span> <span class="pre">(CST</span> <span class="pre">to</span> <span class="pre">TYPE)</span></tt></dt>
+<dd>Convert a constant, CST, to another TYPE. The constraints of the
+operands are the same as those for the <a class="reference internal" href="#i-bitcast"><em>bitcast
+instruction</em></a>.</dd>
+<dt><tt class="docutils literal"><span class="pre">addrspacecast</span> <span class="pre">(CST</span> <span class="pre">to</span> <span class="pre">TYPE)</span></tt></dt>
+<dd>Convert a constant pointer or constant vector of pointer, CST, to another
+TYPE in a different address space. The constraints of the operands are the
+same as those for the <a class="reference internal" href="#i-addrspacecast"><em>addrspacecast instruction</em></a>.</dd>
+<dt><tt class="docutils literal"><span class="pre">getelementptr</span> <span class="pre">(CSTPTR,</span> <span class="pre">IDX0,</span> <span class="pre">IDX1,</span> <span class="pre">...)</span></tt>, <tt class="docutils literal"><span class="pre">getelementptr</span> <span class="pre">inbounds</span> <span class="pre">(CSTPTR,</span> <span class="pre">IDX0,</span> <span class="pre">IDX1,</span> <span class="pre">...)</span></tt></dt>
+<dd>Perform the <a class="reference internal" href="#i-getelementptr"><em>getelementptr operation</em></a> on
+constants. As with the <a class="reference internal" href="#i-getelementptr"><em>getelementptr</em></a>
+instruction, the index list may have zero or more indexes, which are
+required to make sense for the type of “CSTPTR”.</dd>
+<dt><tt class="docutils literal"><span class="pre">select</span> <span class="pre">(COND,</span> <span class="pre">VAL1,</span> <span class="pre">VAL2)</span></tt></dt>
+<dd>Perform the <a class="reference internal" href="#i-select"><em>select operation</em></a> on constants.</dd>
+<dt><tt class="docutils literal"><span class="pre">icmp</span> <span class="pre">COND</span> <span class="pre">(VAL1,</span> <span class="pre">VAL2)</span></tt></dt>
+<dd>Performs the <a class="reference internal" href="#i-icmp"><em>icmp operation</em></a> on constants.</dd>
+<dt><tt class="docutils literal"><span class="pre">fcmp</span> <span class="pre">COND</span> <span class="pre">(VAL1,</span> <span class="pre">VAL2)</span></tt></dt>
+<dd>Performs the <a class="reference internal" href="#i-fcmp"><em>fcmp operation</em></a> on constants.</dd>
+<dt><tt class="docutils literal"><span class="pre">extractelement</span> <span class="pre">(VAL,</span> <span class="pre">IDX)</span></tt></dt>
+<dd>Perform the <a class="reference internal" href="#i-extractelement"><em>extractelement operation</em></a> on
+constants.</dd>
+<dt><tt class="docutils literal"><span class="pre">insertelement</span> <span class="pre">(VAL,</span> <span class="pre">ELT,</span> <span class="pre">IDX)</span></tt></dt>
+<dd>Perform the <a class="reference internal" href="#i-insertelement"><em>insertelement operation</em></a> on
+constants.</dd>
+<dt><tt class="docutils literal"><span class="pre">shufflevector</span> <span class="pre">(VEC1,</span> <span class="pre">VEC2,</span> <span class="pre">IDXMASK)</span></tt></dt>
+<dd>Perform the <a class="reference internal" href="#i-shufflevector"><em>shufflevector operation</em></a> on
+constants.</dd>
+<dt><tt class="docutils literal"><span class="pre">extractvalue</span> <span class="pre">(VAL,</span> <span class="pre">IDX0,</span> <span class="pre">IDX1,</span> <span class="pre">...)</span></tt></dt>
+<dd>Perform the <a class="reference internal" href="#i-extractvalue"><em>extractvalue operation</em></a> on
+constants. The index list is interpreted in a similar manner as
+indices in a ‘<a class="reference internal" href="#i-getelementptr"><em>getelementptr</em></a>‘ operation. At
+least one index value must be specified.</dd>
+<dt><tt class="docutils literal"><span class="pre">insertvalue</span> <span class="pre">(VAL,</span> <span class="pre">ELT,</span> <span class="pre">IDX0,</span> <span class="pre">IDX1,</span> <span class="pre">...)</span></tt></dt>
+<dd>Perform the <a class="reference internal" href="#i-insertvalue"><em>insertvalue operation</em></a> on constants.
+The index list is interpreted in a similar manner as indices in a
+‘<a class="reference internal" href="#i-getelementptr"><em>getelementptr</em></a>‘ operation. At least one index
+value must be specified.</dd>
+<dt><tt class="docutils literal"><span class="pre">OPCODE</span> <span class="pre">(LHS,</span> <span class="pre">RHS)</span></tt></dt>
+<dd>Perform the specified operation of the LHS and RHS constants. OPCODE
+may be any of the <a class="reference internal" href="#binaryops"><em>binary</em></a> or <a class="reference internal" href="#bitwiseops"><em>bitwise
+binary</em></a> operations. The constraints on operands are
+the same as those for the corresponding instruction (e.g. no bitwise
+operations on floating point values are allowed).</dd>
+</dl>
+</div>
+</div>
+<div class="section" id="other-values">
+<h2><a class="toc-backref" href="#id635">Other Values</a><a class="headerlink" href="#other-values" title="Permalink to this headline">¶</a></h2>
+<div class="section" id="inline-assembler-expressions">
+<span id="inlineasmexprs"></span><h3><a class="toc-backref" href="#id636">Inline Assembler Expressions</a><a class="headerlink" href="#inline-assembler-expressions" title="Permalink to this headline">¶</a></h3>
+<p>LLVM supports inline assembler expressions (as opposed to <a class="reference internal" href="#moduleasm"><em>Module-Level
+Inline Assembly</em></a>) through the use of a special value. This
+value represents the inline assembler as a string (containing the
+instructions to emit), a list of operand constraints (stored as a
+string), a flag that indicates whether or not the inline asm expression
+has side effects, and a flag indicating whether the function containing
+the asm needs to align its stack conservatively. An example inline
+assembler expression is:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="k">i32</span> <span class="p">(</span><span class="k">i32</span><span class="p">)</span> <span class="k">asm</span> <span class="s">"bswap $0"</span><span class="p">,</span> <span class="s">"=r,r"</span>
+</pre></div>
+</div>
+<p>Inline assembler expressions may <strong>only</strong> be used as the callee operand
+of a <a class="reference internal" href="#i-call"><em>call</em></a> or an <a class="reference internal" href="#i-invoke"><em>invoke</em></a> instruction.
+Thus, typically we have:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%X</span> <span class="p">=</span> <span class="k">call</span> <span class="k">i32</span> <span class="k">asm</span> <span class="s">"bswap $0"</span><span class="p">,</span> <span class="s">"=r,r"</span><span class="p">(</span><span class="k">i32</span> <span class="nv">%Y</span><span class="p">)</span>
+</pre></div>
+</div>
+<p>Inline asms with side effects not visible in the constraint list must be
+marked as having side effects. This is done through the use of the
+‘<tt class="docutils literal"><span class="pre">sideeffect</span></tt>‘ keyword, like so:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="k">call</span> <span class="kt">void</span> <span class="k">asm</span> <span class="k">sideeffect</span> <span class="s">"eieio"</span><span class="p">,</span> <span class="s">""</span><span class="p">()</span>
+</pre></div>
+</div>
+<p>In some cases inline asms will contain code that will not work unless
+the stack is aligned in some way, such as calls or SSE instructions on
+x86, yet will not contain code that does that alignment within the asm.
+The compiler should make conservative assumptions about what the asm
+might contain and should generate its usual stack alignment code in the
+prologue if the ‘<tt class="docutils literal"><span class="pre">alignstack</span></tt>‘ keyword is present:</p>
+<div class="highlight-llvm"><div class="highlight"><pre>call void asm alignstack "eieio", ""()
+</pre></div>
+</div>
+<p>Inline asms also support using non-standard assembly dialects. The
+assumed dialect is ATT. When the ‘<tt class="docutils literal"><span class="pre">inteldialect</span></tt>‘ keyword is present,
+the inline asm is using the Intel dialect. Currently, ATT and Intel are
+the only supported dialects. An example is:</p>
+<div class="highlight-llvm"><div class="highlight"><pre>call void asm inteldialect "eieio", ""()
+</pre></div>
+</div>
+<p>If multiple keywords appear the ‘<tt class="docutils literal"><span class="pre">sideeffect</span></tt>‘ keyword must come
+first, the ‘<tt class="docutils literal"><span class="pre">alignstack</span></tt>‘ keyword second and the ‘<tt class="docutils literal"><span class="pre">inteldialect</span></tt>‘
+keyword last.</p>
+<div class="section" id="inline-asm-metadata">
+<h4><a class="toc-backref" href="#id637">Inline Asm Metadata</a><a class="headerlink" href="#inline-asm-metadata" title="Permalink to this headline">¶</a></h4>
+<p>The call instructions that wrap inline asm nodes may have a
+“<tt class="docutils literal"><span class="pre">!srcloc</span></tt>” MDNode attached to it that contains a list of constant
+integers. If present, the code generator will use the integer as the
+location cookie value when report errors through the <tt class="docutils literal"><span class="pre">LLVMContext</span></tt>
+error reporting mechanisms. This allows a front-end to correlate backend
+errors that occur with inline asm back to the source code that produced
+it. For example:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="k">call</span> <span class="kt">void</span> <span class="k">asm</span> <span class="k">sideeffect</span> <span class="s">"something bad"</span><span class="p">,</span> <span class="s">""</span><span class="p">(),</span> <span class="nv">!srcloc</span> <span class="nv-Anonymous">!42</span>
+<span class="p">...</span>
+<span class="nv-Anonymous">!42</span> <span class="p">=</span> <span class="p">!{</span> <span class="k">i32</span> <span class="m">1234567</span> <span class="p">}</span>
+</pre></div>
+</div>
+<p>It is up to the front-end to make sense of the magic numbers it places
+in the IR. If the MDNode contains multiple constants, the code generator
+will use the one that corresponds to the line of the asm that the error
+occurs on.</p>
+</div>
+</div>
+</div>
+<div class="section" id="metadata">
+<span id="id4"></span><h2><a class="toc-backref" href="#id638">Metadata</a><a class="headerlink" href="#metadata" title="Permalink to this headline">¶</a></h2>
+<p>LLVM IR allows metadata to be attached to instructions in the program
+that can convey extra information about the code to the optimizers and
+code generator. One example application of metadata is source-level
+debug information. There are two metadata primitives: strings and nodes.</p>
+<p>Metadata does not have a type, and is not a value.  If referenced from a
+<tt class="docutils literal"><span class="pre">call</span></tt> instruction, it uses the <tt class="docutils literal"><span class="pre">metadata</span></tt> type.</p>
+<p>All metadata are identified in syntax by a exclamation point (‘<tt class="docutils literal"><span class="pre">!</span></tt>‘).</p>
+<div class="section" id="metadata-nodes-and-metadata-strings">
+<h3><a class="toc-backref" href="#id639">Metadata Nodes and Metadata Strings</a><a class="headerlink" href="#metadata-nodes-and-metadata-strings" title="Permalink to this headline">¶</a></h3>
+<p>A metadata string is a string surrounded by double quotes. It can
+contain any character by escaping non-printable characters with
+“<tt class="docutils literal"><span class="pre">\xx</span></tt>” where “<tt class="docutils literal"><span class="pre">xx</span></tt>” is the two digit hex code. For example:
+“<tt class="docutils literal"><span class="pre">!"test\00"</span></tt>”.</p>
+<p>Metadata nodes are represented with notation similar to structure
+constants (a comma separated list of elements, surrounded by braces and
+preceded by an exclamation point). Metadata nodes can have any values as
+their operand. For example:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="p">!{</span> <span class="nv">!"test\00"</span><span class="p">,</span> <span class="k">i32</span> <span class="m">10</span><span class="p">}</span>
+</pre></div>
+</div>
+<p>Metadata nodes that aren’t uniqued use the <tt class="docutils literal"><span class="pre">distinct</span></tt> keyword. For example:</p>
+<div class="highlight-llvm"><div class="highlight"><pre>!0 = distinct !{!"test\00", i32 10}
+</pre></div>
+</div>
+<p><tt class="docutils literal"><span class="pre">distinct</span></tt> nodes are useful when nodes shouldn’t be merged based on their
+content.  They can also occur when transformations cause uniquing collisions
+when metadata operands change.</p>
+<p>A <a class="reference internal" href="#namedmetadatastructure"><em>named metadata</em></a> is a collection of
+metadata nodes, which can be looked up in the module symbol table. For
+example:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">!foo</span> <span class="p">=</span> <span class="p">!{</span><span class="nv-Anonymous">!4</span><span class="p">,</span> <span class="nv-Anonymous">!3</span><span class="p">}</span>
+</pre></div>
+</div>
+<p>Metadata can be used as function arguments. Here <tt class="docutils literal"><span class="pre">llvm.dbg.value</span></tt>
+function is using two metadata arguments:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="k">call</span> <span class="kt">void</span> <span class="vg">@llvm.dbg.value</span><span class="p">(</span><span class="kt">metadata</span> <span class="nv-Anonymous">!24</span><span class="p">,</span> <span class="k">i64</span> <span class="m">0</span><span class="p">,</span> <span class="kt">metadata</span> <span class="nv-Anonymous">!25</span><span class="p">)</span>
+</pre></div>
+</div>
+<p>Metadata can be attached with an instruction. Here metadata <tt class="docutils literal"><span class="pre">!21</span></tt> is
+attached to the <tt class="docutils literal"><span class="pre">add</span></tt> instruction using the <tt class="docutils literal"><span class="pre">!dbg</span></tt> identifier:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%indvar.next</span> <span class="p">=</span> <span class="k">add</span> <span class="k">i64</span> <span class="nv">%indvar</span><span class="p">,</span> <span class="m">1</span><span class="p">,</span> <span class="nv">!dbg</span> <span class="nv-Anonymous">!21</span>
+</pre></div>
+</div>
+<p>More information about specific metadata nodes recognized by the
+optimizers and code generator is found below.</p>
+<div class="section" id="specialized-metadata-nodes">
+<h4><a class="toc-backref" href="#id640">Specialized Metadata Nodes</a><a class="headerlink" href="#specialized-metadata-nodes" title="Permalink to this headline">¶</a></h4>
+<p>Specialized metadata nodes are custom data structures in metadata (as opposed
+to generic tuples).  Their fields are labelled, and can be specified in any
+order.</p>
+<div class="section" id="mdlocation">
+<h5><a class="toc-backref" href="#id641">MDLocation</a><a class="headerlink" href="#mdlocation" title="Permalink to this headline">¶</a></h5>
+<p><tt class="docutils literal"><span class="pre">MDLocation</span></tt> nodes represent source debug locations.  The <tt class="docutils literal"><span class="pre">scope:</span></tt> field is
+mandatory.</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv-Anonymous">!0</span> <span class="p">=</span> <span class="nv">!MDLocation</span><span class="p">(</span><span class="nl">line:</span> <span class="m">2900</span><span class="p">,</span> <span class="nl">column:</span> <span class="m">42</span><span class="p">,</span> <span class="nl">scope:</span> <span class="nv-Anonymous">!1</span><span class="p">,</span> <span class="nl">inlinedAt:</span> <span class="nv-Anonymous">!2</span><span class="p">)</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="tbaa-metadata">
+<h4><a class="toc-backref" href="#id642">‘<tt class="docutils literal"><span class="pre">tbaa</span></tt>‘ Metadata</a><a class="headerlink" href="#tbaa-metadata" title="Permalink to this headline">¶</a></h4>
+<p>In LLVM IR, memory does not have types, so LLVM’s own type system is not
+suitable for doing TBAA. Instead, metadata is added to the IR to
+describe a type system of a higher level language. This can be used to
+implement typical C/C++ TBAA, but it can also be used to implement
+custom alias analysis behavior for other languages.</p>
+<p>The current metadata format is very simple. TBAA metadata nodes have up
+to three fields, e.g.:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv-Anonymous">!0</span> <span class="p">=</span> <span class="p">!{</span> <span class="nv">!"an example type tree"</span> <span class="p">}</span>
+<span class="nv-Anonymous">!1</span> <span class="p">=</span> <span class="p">!{</span> <span class="nv">!"int"</span><span class="p">,</span> <span class="nv-Anonymous">!0</span> <span class="p">}</span>
+<span class="nv-Anonymous">!2</span> <span class="p">=</span> <span class="p">!{</span> <span class="nv">!"float"</span><span class="p">,</span> <span class="nv-Anonymous">!0</span> <span class="p">}</span>
+<span class="nv-Anonymous">!3</span> <span class="p">=</span> <span class="p">!{</span> <span class="nv">!"const float"</span><span class="p">,</span> <span class="nv-Anonymous">!2</span><span class="p">,</span> <span class="k">i64</span> <span class="m">1</span> <span class="p">}</span>
+</pre></div>
+</div>
+<p>The first field is an identity field. It can be any value, usually a
+metadata string, which uniquely identifies the type. The most important
+name in the tree is the name of the root node. Two trees with different
+root node names are entirely disjoint, even if they have leaves with
+common names.</p>
+<p>The second field identifies the type’s parent node in the tree, or is
+null or omitted for a root node. A type is considered to alias all of
+its descendants and all of its ancestors in the tree. Also, a type is
+considered to alias all types in other trees, so that bitcode produced
+from multiple front-ends is handled conservatively.</p>
+<p>If the third field is present, it’s an integer which if equal to 1
+indicates that the type is “constant” (meaning
+<tt class="docutils literal"><span class="pre">pointsToConstantMemory</span></tt> should return true; see <a class="reference external" href="AliasAnalysis.html#OtherItfs">other useful
+AliasAnalysis methods</a>).</p>
+</div>
+<div class="section" id="tbaa-struct-metadata">
+<h4><a class="toc-backref" href="#id643">‘<tt class="docutils literal"><span class="pre">tbaa.struct</span></tt>‘ Metadata</a><a class="headerlink" href="#tbaa-struct-metadata" title="Permalink to this headline">¶</a></h4>
+<p>The <a class="reference internal" href="#int-memcpy"><em>llvm.memcpy</em></a> is often used to implement
+aggregate assignment operations in C and similar languages, however it
+is defined to copy a contiguous region of memory, which is more than
+strictly necessary for aggregate types which contain holes due to
+padding. Also, it doesn’t contain any TBAA information about the fields
+of the aggregate.</p>
+<p><tt class="docutils literal"><span class="pre">!tbaa.struct</span></tt> metadata can describe which memory subregions in a
+memcpy are padding and what the TBAA tags of the struct are.</p>
+<p>The current metadata format is very simple. <tt class="docutils literal"><span class="pre">!tbaa.struct</span></tt> metadata
+nodes are a list of operands which are in conceptual groups of three.
+For each group of three, the first operand gives the byte offset of a
+field in bytes, the second gives its size in bytes, and the third gives
+its tbaa tag. e.g.:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv-Anonymous">!4</span> <span class="p">=</span> <span class="p">!{</span> <span class="k">i64</span> <span class="m">0</span><span class="p">,</span> <span class="k">i64</span> <span class="m">4</span><span class="p">,</span> <span class="nv-Anonymous">!1</span><span class="p">,</span> <span class="k">i64</span> <span class="m">8</span><span class="p">,</span> <span class="k">i64</span> <span class="m">4</span><span class="p">,</span> <span class="nv-Anonymous">!2</span> <span class="p">}</span>
+</pre></div>
+</div>
+<p>This describes a struct with two fields. The first is at offset 0 bytes
+with size 4 bytes, and has tbaa tag !1. The second is at offset 8 bytes
+and has size 4 bytes and has tbaa tag !2.</p>
+<p>Note that the fields need not be contiguous. In this example, there is a
+4 byte gap between the two fields. This gap represents padding which
+does not carry useful data and need not be preserved.</p>
+</div>
+<div class="section" id="noalias-and-alias-scope-metadata">
+<h4><a class="toc-backref" href="#id644">‘<tt class="docutils literal"><span class="pre">noalias</span></tt>‘ and ‘<tt class="docutils literal"><span class="pre">alias.scope</span></tt>‘ Metadata</a><a class="headerlink" href="#noalias-and-alias-scope-metadata" title="Permalink to this headline">¶</a></h4>
+<p><tt class="docutils literal"><span class="pre">noalias</span></tt> and <tt class="docutils literal"><span class="pre">alias.scope</span></tt> metadata provide the ability to specify generic
+noalias memory-access sets. This means that some collection of memory access
+instructions (loads, stores, memory-accessing calls, etc.) that carry
+<tt class="docutils literal"><span class="pre">noalias</span></tt> metadata can specifically be specified not to alias with some other
+collection of memory access instructions that carry <tt class="docutils literal"><span class="pre">alias.scope</span></tt> metadata.
+Each type of metadata specifies a list of scopes where each scope has an id and
+a domain. When evaluating an aliasing query, if for some some domain, the set
+of scopes with that domain in one instruction’s <tt class="docutils literal"><span class="pre">alias.scope</span></tt> list is a
+subset of (or qual to) the set of scopes for that domain in another
+instruction’s <tt class="docutils literal"><span class="pre">noalias</span></tt> list, then the two memory accesses are assumed not to
+alias.</p>
+<p>The metadata identifying each domain is itself a list containing one or two
+entries. The first entry is the name of the domain. Note that if the name is a
+string then it can be combined accross functions and translation units. A
+self-reference can be used to create globally unique domain names. A
+descriptive string may optionally be provided as a second list entry.</p>
+<p>The metadata identifying each scope is also itself a list containing two or
+three entries. The first entry is the name of the scope. Note that if the name
+is a string then it can be combined accross functions and translation units. A
+self-reference can be used to create globally unique scope names. A metadata
+reference to the scope’s domain is the second entry. A descriptive string may
+optionally be provided as a third list entry.</p>
+<p>For example,</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="c">; Two scope domains:</span>
+<span class="nv-Anonymous">!0</span> <span class="p">=</span> <span class="p">!{</span><span class="nv-Anonymous">!0</span><span class="p">}</span>
+<span class="nv-Anonymous">!1</span> <span class="p">=</span> <span class="p">!{</span><span class="nv-Anonymous">!1</span><span class="p">}</span>
+
+<span class="c">; Some scopes in these domains:</span>
+<span class="nv-Anonymous">!2</span> <span class="p">=</span> <span class="p">!{</span><span class="nv-Anonymous">!2</span><span class="p">,</span> <span class="nv-Anonymous">!0</span><span class="p">}</span>
+<span class="nv-Anonymous">!3</span> <span class="p">=</span> <span class="p">!{</span><span class="nv-Anonymous">!3</span><span class="p">,</span> <span class="nv-Anonymous">!0</span><span class="p">}</span>
+<span class="nv-Anonymous">!4</span> <span class="p">=</span> <span class="p">!{</span><span class="nv-Anonymous">!4</span><span class="p">,</span> <span class="nv-Anonymous">!1</span><span class="p">}</span>
+
+<span class="c">; Some scope lists:</span>
+<span class="nv-Anonymous">!5</span> <span class="p">=</span> <span class="p">!{</span><span class="nv-Anonymous">!4</span><span class="p">}</span> <span class="c">; A list containing only scope !4</span>
+<span class="nv-Anonymous">!6</span> <span class="p">=</span> <span class="p">!{</span><span class="nv-Anonymous">!4</span><span class="p">,</span> <span class="nv-Anonymous">!3</span><span class="p">,</span> <span class="nv-Anonymous">!2</span><span class="p">}</span>
+<span class="nv-Anonymous">!7</span> <span class="p">=</span> <span class="p">!{</span><span class="nv-Anonymous">!3</span><span class="p">}</span>
+
+<span class="c">; These two instructions don't alias:</span>
+<span class="nv-Anonymous">%0</span> <span class="p">=</span> <span class="k">load</span> <span class="kt">float</span><span class="p">*</span> <span class="nv">%c</span><span class="p">,</span> <span class="k">align</span> <span class="m">4</span><span class="p">,</span> <span class="nv">!alias.scope</span> <span class="nv-Anonymous">!5</span>
+<span class="k">store</span> <span class="kt">float</span> <span class="nv-Anonymous">%0</span><span class="p">,</span> <span class="kt">float</span><span class="p">*</span> <span class="nv">%arrayidx.i</span><span class="p">,</span> <span class="k">align</span> <span class="m">4</span><span class="p">,</span> <span class="nv">!noalias</span> <span class="nv-Anonymous">!5</span>
+
+<span class="c">; These two instructions also don't alias (for domain !1, the set of scopes</span>
+<span class="c">; in the !alias.scope equals that in the !noalias list):</span>
+<span class="nv-Anonymous">%2</span> <span class="p">=</span> <span class="k">load</span> <span class="kt">float</span><span class="p">*</span> <span class="nv">%c</span><span class="p">,</span> <span class="k">align</span> <span class="m">4</span><span class="p">,</span> <span class="nv">!alias.scope</span> <span class="nv-Anonymous">!5</span>
+<span class="k">store</span> <span class="kt">float</span> <span class="nv-Anonymous">%2</span><span class="p">,</span> <span class="kt">float</span><span class="p">*</span> <span class="nv">%arrayidx.i2</span><span class="p">,</span> <span class="k">align</span> <span class="m">4</span><span class="p">,</span> <span class="nv">!noalias</span> <span class="nv-Anonymous">!6</span>
+
+<span class="c">; These two instructions don't alias (for domain !0, the set of scopes in</span>
+<span class="c">; the !noalias list is not a superset of, or equal to, the scopes in the</span>
+<span class="c">; !alias.scope list):</span>
+<span class="nv-Anonymous">%2</span> <span class="p">=</span> <span class="k">load</span> <span class="kt">float</span><span class="p">*</span> <span class="nv">%c</span><span class="p">,</span> <span class="k">align</span> <span class="m">4</span><span class="p">,</span> <span class="nv">!alias.scope</span> <span class="nv-Anonymous">!6</span>
+<span class="k">store</span> <span class="kt">float</span> <span class="nv-Anonymous">%0</span><span class="p">,</span> <span class="kt">float</span><span class="p">*</span> <span class="nv">%arrayidx.i</span><span class="p">,</span> <span class="k">align</span> <span class="m">4</span><span class="p">,</span> <span class="nv">!noalias</span> <span class="nv-Anonymous">!7</span>
+</pre></div>
+</div>
+</div>
+<div class="section" id="fpmath-metadata">
+<h4><a class="toc-backref" href="#id645">‘<tt class="docutils literal"><span class="pre">fpmath</span></tt>‘ Metadata</a><a class="headerlink" href="#fpmath-metadata" title="Permalink to this headline">¶</a></h4>
+<p><tt class="docutils literal"><span class="pre">fpmath</span></tt> metadata may be attached to any instruction of floating point
+type. It can be used to express the maximum acceptable error in the
+result of that instruction, in ULPs, thus potentially allowing the
+compiler to use a more efficient but less accurate method of computing
+it. ULP is defined as follows:</p>
+<blockquote>
+<div>If <tt class="docutils literal"><span class="pre">x</span></tt> is a real number that lies between two finite consecutive
+floating-point numbers <tt class="docutils literal"><span class="pre">a</span></tt> and <tt class="docutils literal"><span class="pre">b</span></tt>, without being equal to one
+of them, then <tt class="docutils literal"><span class="pre">ulp(x)</span> <span class="pre">=</span> <span class="pre">|b</span> <span class="pre">-</span> <span class="pre">a|</span></tt>, otherwise <tt class="docutils literal"><span class="pre">ulp(x)</span></tt> is the
+distance between the two non-equal finite floating-point numbers
+nearest <tt class="docutils literal"><span class="pre">x</span></tt>. Moreover, <tt class="docutils literal"><span class="pre">ulp(NaN)</span></tt> is <tt class="docutils literal"><span class="pre">NaN</span></tt>.</div></blockquote>
+<p>The metadata node shall consist of a single positive floating point
+number representing the maximum relative error, for example:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv-Anonymous">!0</span> <span class="p">=</span> <span class="p">!{</span> <span class="kt">float</span> <span class="m">2.5</span> <span class="p">}</span> <span class="c">; maximum acceptable inaccuracy is 2.5 ULPs</span>
+</pre></div>
+</div>
+</div>
+<div class="section" id="range-metadata">
+<h4><a class="toc-backref" href="#id646">‘<tt class="docutils literal"><span class="pre">range</span></tt>‘ Metadata</a><a class="headerlink" href="#range-metadata" title="Permalink to this headline">¶</a></h4>
+<p><tt class="docutils literal"><span class="pre">range</span></tt> metadata may be attached only to <tt class="docutils literal"><span class="pre">load</span></tt>, <tt class="docutils literal"><span class="pre">call</span></tt> and <tt class="docutils literal"><span class="pre">invoke</span></tt> of
+integer types. It expresses the possible ranges the loaded value or the value
+returned by the called function at this call site is in. The ranges are
+represented with a flattened list of integers. The loaded value or the value
+returned is known to be in the union of the ranges defined by each consecutive
+pair. Each pair has the following properties:</p>
+<ul class="simple">
+<li>The type must match the type loaded by the instruction.</li>
+<li>The pair <tt class="docutils literal"><span class="pre">a,b</span></tt> represents the range <tt class="docutils literal"><span class="pre">[a,b)</span></tt>.</li>
+<li>Both <tt class="docutils literal"><span class="pre">a</span></tt> and <tt class="docutils literal"><span class="pre">b</span></tt> are constants.</li>
+<li>The range is allowed to wrap.</li>
+<li>The range should not represent the full or empty set. That is,
+<tt class="docutils literal"><span class="pre">a!=b</span></tt>.</li>
+</ul>
+<p>In addition, the pairs must be in signed order of the lower bound and
+they must be non-contiguous.</p>
+<p>Examples:</p>
+<div class="highlight-llvm"><div class="highlight"><pre>  <span class="nv">%a</span> <span class="p">=</span> <span class="k">load</span> <span class="k">i8</span><span class="p">*</span> <span class="nv">%x</span><span class="p">,</span> <span class="k">align</span> <span class="m">1</span><span class="p">,</span> <span class="nv">!range</span> <span class="nv-Anonymous">!0</span> <span class="c">; Can only be 0 or 1</span>
+  <span class="nv">%b</span> <span class="p">=</span> <span class="k">load</span> <span class="k">i8</span><span class="p">*</span> <span class="nv">%y</span><span class="p">,</span> <span class="k">align</span> <span class="m">1</span><span class="p">,</span> <span class="nv">!range</span> <span class="nv-Anonymous">!1</span> <span class="c">; Can only be 255 (-1), 0 or 1</span>
+  <span class="nv">%c</span> <span class="p">=</span> <span class="k">call</span> <span class="k">i8</span> <span class="vg">@foo</span><span class="p">(),</span>       <span class="nv">!range</span> <span class="nv-Anonymous">!2</span> <span class="c">; Can only be 0, 1, 3, 4 or 5</span>
+  <span class="nv">%d</span> <span class="p">=</span> <span class="k">invoke</span> <span class="k">i8</span> <span class="vg">@bar</span><span class="p">()</span> <span class="k">to</span> <span class="kt">label</span> <span class="nv">%cont</span>
+         <span class="k">unwind</span> <span class="kt">label</span> <span class="nv">%lpad</span><span class="p">,</span> <span class="nv">!range</span> <span class="nv-Anonymous">!3</span> <span class="c">; Can only be -2, -1, 3, 4 or 5</span>
+<span class="p">...</span>
+<span class="nv-Anonymous">!0</span> <span class="p">=</span> <span class="p">!{</span> <span class="k">i8</span> <span class="m">0</span><span class="p">,</span> <span class="k">i8</span> <span class="m">2</span> <span class="p">}</span>
+<span class="nv-Anonymous">!1</span> <span class="p">=</span> <span class="p">!{</span> <span class="k">i8</span> <span class="m">255</span><span class="p">,</span> <span class="k">i8</span> <span class="m">2</span> <span class="p">}</span>
+<span class="nv-Anonymous">!2</span> <span class="p">=</span> <span class="p">!{</span> <span class="k">i8</span> <span class="m">0</span><span class="p">,</span> <span class="k">i8</span> <span class="m">2</span><span class="p">,</span> <span class="k">i8</span> <span class="m">3</span><span class="p">,</span> <span class="k">i8</span> <span class="m">6</span> <span class="p">}</span>
+<span class="nv-Anonymous">!3</span> <span class="p">=</span> <span class="p">!{</span> <span class="k">i8</span> <span class="m">-2</span><span class="p">,</span> <span class="k">i8</span> <span class="m">0</span><span class="p">,</span> <span class="k">i8</span> <span class="m">3</span><span class="p">,</span> <span class="k">i8</span> <span class="m">6</span> <span class="p">}</span>
+</pre></div>
+</div>
+</div>
+<div class="section" id="llvm-loop">
+<h4><a class="toc-backref" href="#id647">‘<tt class="docutils literal"><span class="pre">llvm.loop</span></tt>‘</a><a class="headerlink" href="#llvm-loop" title="Permalink to this headline">¶</a></h4>
+<p>It is sometimes useful to attach information to loop constructs. Currently,
+loop metadata is implemented as metadata attached to the branch instruction
+in the loop latch block. This type of metadata refer to a metadata node that is
+guaranteed to be separate for each loop. The loop identifier metadata is
+specified with the name <tt class="docutils literal"><span class="pre">llvm.loop</span></tt>.</p>
+<p>The loop identifier metadata is implemented using a metadata that refers to
+itself to avoid merging it with any other identifier metadata, e.g.,
+during module linkage or function inlining. That is, each loop should refer
+to their own identification metadata even if they reside in separate functions.
+The following example contains loop identifier metadata for two separate loop
+constructs:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv-Anonymous">!0</span> <span class="p">=</span> <span class="p">!{</span><span class="nv-Anonymous">!0</span><span class="p">}</span>
+<span class="nv-Anonymous">!1</span> <span class="p">=</span> <span class="p">!{</span><span class="nv-Anonymous">!1</span><span class="p">}</span>
+</pre></div>
+</div>
+<p>The loop identifier metadata can be used to specify additional
+per-loop metadata. Any operands after the first operand can be treated
+as user-defined metadata. For example the <tt class="docutils literal"><span class="pre">llvm.loop.unroll.count</span></tt>
+suggests an unroll factor to the loop unroller:</p>
+<div class="highlight-llvm"><div class="highlight"><pre>  <span class="k">br</span> <span class="k">i1</span> <span class="nv">%exitcond</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%._crit_edge</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%.lr.ph</span><span class="p">,</span> <span class="nv">!llvm.loop</span> <span class="nv-Anonymous">!0</span>
+<span class="p">...</span>
+<span class="nv-Anonymous">!0</span> <span class="p">=</span> <span class="p">!{</span><span class="nv-Anonymous">!0</span><span class="p">,</span> <span class="nv-Anonymous">!1</span><span class="p">}</span>
+<span class="nv-Anonymous">!1</span> <span class="p">=</span> <span class="p">!{</span><span class="nv">!"llvm.loop.unroll.count"</span><span class="p">,</span> <span class="k">i32</span> <span class="m">4</span><span class="p">}</span>
+</pre></div>
+</div>
+</div>
+<div class="section" id="llvm-loop-vectorize-and-llvm-loop-interleave">
+<h4><a class="toc-backref" href="#id648">‘<tt class="docutils literal"><span class="pre">llvm.loop.vectorize</span></tt>‘ and ‘<tt class="docutils literal"><span class="pre">llvm.loop.interleave</span></tt>‘</a><a class="headerlink" href="#llvm-loop-vectorize-and-llvm-loop-interleave" title="Permalink to this headline">¶</a></h4>
+<p>Metadata prefixed with <tt class="docutils literal"><span class="pre">llvm.loop.vectorize</span></tt> or <tt class="docutils literal"><span class="pre">llvm.loop.interleave</span></tt> are
+used to control per-loop vectorization and interleaving parameters such as
+vectorization width and interleave count.  These metadata should be used in
+conjunction with <tt class="docutils literal"><span class="pre">llvm.loop</span></tt> loop identification metadata.  The
+<tt class="docutils literal"><span class="pre">llvm.loop.vectorize</span></tt> and <tt class="docutils literal"><span class="pre">llvm.loop.interleave</span></tt> metadata are only
+optimization hints and the optimizer will only interleave and vectorize loops if
+it believes it is safe to do so.  The <tt class="docutils literal"><span class="pre">llvm.mem.parallel_loop_access</span></tt> metadata
+which contains information about loop-carried memory dependencies can be helpful
+in determining the safety of these transformations.</p>
+</div>
+<div class="section" id="llvm-loop-interleave-count-metadata">
+<h4><a class="toc-backref" href="#id649">‘<tt class="docutils literal"><span class="pre">llvm.loop.interleave.count</span></tt>‘ Metadata</a><a class="headerlink" href="#llvm-loop-interleave-count-metadata" title="Permalink to this headline">¶</a></h4>
+<p>This metadata suggests an interleave count to the loop interleaver.
+The first operand is the string <tt class="docutils literal"><span class="pre">llvm.loop.interleave.count</span></tt> and the
+second operand is an integer specifying the interleave count. For
+example:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv-Anonymous">!0</span> <span class="p">=</span> <span class="p">!{</span><span class="nv">!"llvm.loop.interleave.count"</span><span class="p">,</span> <span class="k">i32</span> <span class="m">4</span><span class="p">}</span>
+</pre></div>
+</div>
+<p>Note that setting <tt class="docutils literal"><span class="pre">llvm.loop.interleave.count</span></tt> to 1 disables interleaving
+multiple iterations of the loop.  If <tt class="docutils literal"><span class="pre">llvm.loop.interleave.count</span></tt> is set to 0
+then the interleave count will be determined automatically.</p>
+</div>
+<div class="section" id="llvm-loop-vectorize-enable-metadata">
+<h4><a class="toc-backref" href="#id650">‘<tt class="docutils literal"><span class="pre">llvm.loop.vectorize.enable</span></tt>‘ Metadata</a><a class="headerlink" href="#llvm-loop-vectorize-enable-metadata" title="Permalink to this headline">¶</a></h4>
+<p>This metadata selectively enables or disables vectorization for the loop. The
+first operand is the string <tt class="docutils literal"><span class="pre">llvm.loop.vectorize.enable</span></tt> and the second operand
+is a bit.  If the bit operand value is 1 vectorization is enabled. A value of
+0 disables vectorization:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv-Anonymous">!0</span> <span class="p">=</span> <span class="p">!{</span><span class="nv">!"llvm.loop.vectorize.enable"</span><span class="p">,</span> <span class="k">i1</span> <span class="m">0</span><span class="p">}</span>
+<span class="nv-Anonymous">!1</span> <span class="p">=</span> <span class="p">!{</span><span class="nv">!"llvm.loop.vectorize.enable"</span><span class="p">,</span> <span class="k">i1</span> <span class="m">1</span><span class="p">}</span>
+</pre></div>
+</div>
+</div>
+<div class="section" id="llvm-loop-vectorize-width-metadata">
+<h4><a class="toc-backref" href="#id651">‘<tt class="docutils literal"><span class="pre">llvm.loop.vectorize.width</span></tt>‘ Metadata</a><a class="headerlink" href="#llvm-loop-vectorize-width-metadata" title="Permalink to this headline">¶</a></h4>
+<p>This metadata sets the target width of the vectorizer. The first
+operand is the string <tt class="docutils literal"><span class="pre">llvm.loop.vectorize.width</span></tt> and the second
+operand is an integer specifying the width. For example:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv-Anonymous">!0</span> <span class="p">=</span> <span class="p">!{</span><span class="nv">!"llvm.loop.vectorize.width"</span><span class="p">,</span> <span class="k">i32</span> <span class="m">4</span><span class="p">}</span>
+</pre></div>
+</div>
+<p>Note that setting <tt class="docutils literal"><span class="pre">llvm.loop.vectorize.width</span></tt> to 1 disables
+vectorization of the loop.  If <tt class="docutils literal"><span class="pre">llvm.loop.vectorize.width</span></tt> is set to
+0 or if the loop does not have this metadata the width will be
+determined automatically.</p>
+</div>
+<div class="section" id="llvm-loop-unroll">
+<h4><a class="toc-backref" href="#id652">‘<tt class="docutils literal"><span class="pre">llvm.loop.unroll</span></tt>‘</a><a class="headerlink" href="#llvm-loop-unroll" title="Permalink to this headline">¶</a></h4>
+<p>Metadata prefixed with <tt class="docutils literal"><span class="pre">llvm.loop.unroll</span></tt> are loop unrolling
+optimization hints such as the unroll factor. <tt class="docutils literal"><span class="pre">llvm.loop.unroll</span></tt>
+metadata should be used in conjunction with <tt class="docutils literal"><span class="pre">llvm.loop</span></tt> loop
+identification metadata. The <tt class="docutils literal"><span class="pre">llvm.loop.unroll</span></tt> metadata are only
+optimization hints and the unrolling will only be performed if the
+optimizer believes it is safe to do so.</p>
+</div>
+<div class="section" id="llvm-loop-unroll-count-metadata">
+<h4><a class="toc-backref" href="#id653">‘<tt class="docutils literal"><span class="pre">llvm.loop.unroll.count</span></tt>‘ Metadata</a><a class="headerlink" href="#llvm-loop-unroll-count-metadata" title="Permalink to this headline">¶</a></h4>
+<p>This metadata suggests an unroll factor to the loop unroller. The
+first operand is the string <tt class="docutils literal"><span class="pre">llvm.loop.unroll.count</span></tt> and the second
+operand is a positive integer specifying the unroll factor. For
+example:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv-Anonymous">!0</span> <span class="p">=</span> <span class="p">!{</span><span class="nv">!"llvm.loop.unroll.count"</span><span class="p">,</span> <span class="k">i32</span> <span class="m">4</span><span class="p">}</span>
+</pre></div>
+</div>
+<p>If the trip count of the loop is less than the unroll count the loop
+will be partially unrolled.</p>
+</div>
+<div class="section" id="llvm-loop-unroll-disable-metadata">
+<h4><a class="toc-backref" href="#id654">‘<tt class="docutils literal"><span class="pre">llvm.loop.unroll.disable</span></tt>‘ Metadata</a><a class="headerlink" href="#llvm-loop-unroll-disable-metadata" title="Permalink to this headline">¶</a></h4>
+<p>This metadata either disables loop unrolling. The metadata has a single operand
+which is the string <tt class="docutils literal"><span class="pre">llvm.loop.unroll.disable</span></tt>.  For example:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv-Anonymous">!0</span> <span class="p">=</span> <span class="p">!{</span><span class="nv">!"llvm.loop.unroll.disable"</span><span class="p">}</span>
+</pre></div>
+</div>
+</div>
+<div class="section" id="llvm-loop-unroll-full-metadata">
+<h4><a class="toc-backref" href="#id655">‘<tt class="docutils literal"><span class="pre">llvm.loop.unroll.full</span></tt>‘ Metadata</a><a class="headerlink" href="#llvm-loop-unroll-full-metadata" title="Permalink to this headline">¶</a></h4>
+<p>This metadata either suggests that the loop should be unrolled fully. The
+metadata has a single operand which is the string <tt class="docutils literal"><span class="pre">llvm.loop.unroll.disable</span></tt>.
+For example:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv-Anonymous">!0</span> <span class="p">=</span> <span class="p">!{</span><span class="nv">!"llvm.loop.unroll.full"</span><span class="p">}</span>
+</pre></div>
+</div>
+</div>
+<div class="section" id="llvm-mem">
+<h4><a class="toc-backref" href="#id656">‘<tt class="docutils literal"><span class="pre">llvm.mem</span></tt>‘</a><a class="headerlink" href="#llvm-mem" title="Permalink to this headline">¶</a></h4>
+<p>Metadata types used to annotate memory accesses with information helpful
+for optimizations are prefixed with <tt class="docutils literal"><span class="pre">llvm.mem</span></tt>.</p>
+</div>
+<div class="section" id="llvm-mem-parallel-loop-access-metadata">
+<h4><a class="toc-backref" href="#id657">‘<tt class="docutils literal"><span class="pre">llvm.mem.parallel_loop_access</span></tt>‘ Metadata</a><a class="headerlink" href="#llvm-mem-parallel-loop-access-metadata" title="Permalink to this headline">¶</a></h4>
+<p>The <tt class="docutils literal"><span class="pre">llvm.mem.parallel_loop_access</span></tt> metadata refers to a loop identifier,
+or metadata containing a list of loop identifiers for nested loops.
+The metadata is attached to memory accessing instructions and denotes that
+no loop carried memory dependence exist between it and other instructions denoted
+with the same loop identifier.</p>
+<p>Precisely, given two instructions <tt class="docutils literal"><span class="pre">m1</span></tt> and <tt class="docutils literal"><span class="pre">m2</span></tt> that both have the
+<tt class="docutils literal"><span class="pre">llvm.mem.parallel_loop_access</span></tt> metadata, with <tt class="docutils literal"><span class="pre">L1</span></tt> and <tt class="docutils literal"><span class="pre">L2</span></tt> being the
+set of loops associated with that metadata, respectively, then there is no loop
+carried dependence between <tt class="docutils literal"><span class="pre">m1</span></tt> and <tt class="docutils literal"><span class="pre">m2</span></tt> for loops in both <tt class="docutils literal"><span class="pre">L1</span></tt> and
+<tt class="docutils literal"><span class="pre">L2</span></tt>.</p>
+<p>As a special case, if all memory accessing instructions in a loop have
+<tt class="docutils literal"><span class="pre">llvm.mem.parallel_loop_access</span></tt> metadata that refers to that loop, then the
+loop has no loop carried memory dependences and is considered to be a parallel
+loop.</p>
+<p>Note that if not all memory access instructions have such metadata referring to
+the loop, then the loop is considered not being trivially parallel. Additional
+memory dependence analysis is required to make that determination.  As a fail
+safe mechanism, this causes loops that were originally parallel to be considered
+sequential (if optimization passes that are unaware of the parallel semantics
+insert new memory instructions into the loop body).</p>
+<p>Example of a loop that is considered parallel due to its correct use of
+both <tt class="docutils literal"><span class="pre">llvm.loop</span></tt> and <tt class="docutils literal"><span class="pre">llvm.mem.parallel_loop_access</span></tt>
+metadata types that refer to the same loop identifier metadata.</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nl">for.body:</span>
+  <span class="p">...</span>
+  <span class="nv">%val0</span> <span class="p">=</span> <span class="k">load</span> <span class="k">i32</span><span class="p">*</span> <span class="nv">%arrayidx</span><span class="p">,</span> <span class="nv">!llvm.mem.parallel_loop_access</span> <span class="nv-Anonymous">!0</span>
+  <span class="p">...</span>
+  <span class="k">store</span> <span class="k">i32</span> <span class="nv">%val0</span><span class="p">,</span> <span class="k">i32</span><span class="p">*</span> <span class="nv">%arrayidx1</span><span class="p">,</span> <span class="nv">!llvm.mem.parallel_loop_access</span> <span class="nv-Anonymous">!0</span>
+  <span class="p">...</span>
+  <span class="k">br</span> <span class="k">i1</span> <span class="nv">%exitcond</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%for.end</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%for.body</span><span class="p">,</span> <span class="nv">!llvm.loop</span> <span class="nv-Anonymous">!0</span>
+
+<span class="nl">for.end:</span>
+<span class="p">...</span>
+<span class="nv-Anonymous">!0</span> <span class="p">=</span> <span class="p">!{</span><span class="nv-Anonymous">!0</span><span class="p">}</span>
+</pre></div>
+</div>
+<p>It is also possible to have nested parallel loops. In that case the
+memory accesses refer to a list of loop identifier metadata nodes instead of
+the loop identifier metadata node directly:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nl">outer.for.body:</span>
+  <span class="p">...</span>
+  <span class="nv">%val1</span> <span class="p">=</span> <span class="k">load</span> <span class="k">i32</span><span class="p">*</span> <span class="nv">%arrayidx3</span><span class="p">,</span> <span class="nv">!llvm.mem.parallel_loop_access</span> <span class="nv-Anonymous">!2</span>
+  <span class="p">...</span>
+  <span class="k">br</span> <span class="kt">label</span> <span class="nv">%inner.for.body</span>
+
+<span class="nl">inner.for.body:</span>
+  <span class="p">...</span>
+  <span class="nv">%val0</span> <span class="p">=</span> <span class="k">load</span> <span class="k">i32</span><span class="p">*</span> <span class="nv">%arrayidx1</span><span class="p">,</span> <span class="nv">!llvm.mem.parallel_loop_access</span> <span class="nv-Anonymous">!0</span>
+  <span class="p">...</span>
+  <span class="k">store</span> <span class="k">i32</span> <span class="nv">%val0</span><span class="p">,</span> <span class="k">i32</span><span class="p">*</span> <span class="nv">%arrayidx2</span><span class="p">,</span> <span class="nv">!llvm.mem.parallel_loop_access</span> <span class="nv-Anonymous">!0</span>
+  <span class="p">...</span>
+  <span class="k">br</span> <span class="k">i1</span> <span class="nv">%exitcond</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%inner.for.end</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%inner.for.body</span><span class="p">,</span> <span class="nv">!llvm.loop</span> <span class="nv-Anonymous">!1</span>
+
+<span class="nl">inner.for.end:</span>
+  <span class="p">...</span>
+  <span class="k">store</span> <span class="k">i32</span> <span class="nv">%val1</span><span class="p">,</span> <span class="k">i32</span><span class="p">*</span> <span class="nv">%arrayidx4</span><span class="p">,</span> <span class="nv">!llvm.mem.parallel_loop_access</span> <span class="nv-Anonymous">!2</span>
+  <span class="p">...</span>
+  <span class="k">br</span> <span class="k">i1</span> <span class="nv">%exitcond</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%outer.for.end</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%outer.for.body</span><span class="p">,</span> <span class="nv">!llvm.loop</span> <span class="nv-Anonymous">!2</span>
+
+<span class="nl">outer.for.end:</span>                                          <span class="c">; preds = %for.body</span>
+<span class="p">...</span>
+<span class="nv-Anonymous">!0</span> <span class="p">=</span> <span class="p">!{</span><span class="nv-Anonymous">!1</span><span class="p">,</span> <span class="nv-Anonymous">!2</span><span class="p">}</span> <span class="c">; a list of loop identifiers</span>
+<span class="nv-Anonymous">!1</span> <span class="p">=</span> <span class="p">!{</span><span class="nv-Anonymous">!1</span><span class="p">}</span> <span class="c">; an identifier for the inner loop</span>
+<span class="nv-Anonymous">!2</span> <span class="p">=</span> <span class="p">!{</span><span class="nv-Anonymous">!2</span><span class="p">}</span> <span class="c">; an identifier for the outer loop</span>
+</pre></div>
+</div>
+</div>
+</div>
+</div>
+<div class="section" id="module-flags-metadata">
+<h2><a class="toc-backref" href="#id658">Module Flags Metadata</a><a class="headerlink" href="#module-flags-metadata" title="Permalink to this headline">¶</a></h2>
+<p>Information about the module as a whole is difficult to convey to LLVM’s
+subsystems. The LLVM IR isn’t sufficient to transmit this information.
+The <tt class="docutils literal"><span class="pre">llvm.module.flags</span></tt> named metadata exists in order to facilitate
+this. These flags are in the form of key / value pairs — much like a
+dictionary — making it easy for any subsystem who cares about a flag to
+look it up.</p>
+<p>The <tt class="docutils literal"><span class="pre">llvm.module.flags</span></tt> metadata contains a list of metadata triplets.
+Each triplet has the following form:</p>
+<ul class="simple">
+<li>The first element is a <em>behavior</em> flag, which specifies the behavior
+when two (or more) modules are merged together, and it encounters two
+(or more) metadata with the same ID. The supported behaviors are
+described below.</li>
+<li>The second element is a metadata string that is a unique ID for the
+metadata. Each module may only have one flag entry for each unique ID (not
+including entries with the <strong>Require</strong> behavior).</li>
+<li>The third element is the value of the flag.</li>
+</ul>
+<p>When two (or more) modules are merged together, the resulting
+<tt class="docutils literal"><span class="pre">llvm.module.flags</span></tt> metadata is the union of the modules’ flags. That is, for
+each unique metadata ID string, there will be exactly one entry in the merged
+modules <tt class="docutils literal"><span class="pre">llvm.module.flags</span></tt> metadata table, and the value for that entry will
+be determined by the merge behavior flag, as described below. The only exception
+is that entries with the <em>Require</em> behavior are always preserved.</p>
+<p>The following behaviors are supported:</p>
+<table border="1" class="docutils">
+<colgroup>
+<col width="10%" />
+<col width="90%" />
+</colgroup>
+<thead valign="bottom">
+<tr class="row-odd"><th class="head">Value</th>
+<th class="head">Behavior</th>
+</tr>
+</thead>
+<tbody valign="top">
+<tr class="row-even"><td>1</td>
+<td><dl class="first last docutils">
+<dt><strong>Error</strong></dt>
+<dd>Emits an error if two values disagree, otherwise the resulting value
+is that of the operands.</dd>
+</dl>
+</td>
+</tr>
+<tr class="row-odd"><td>2</td>
+<td><dl class="first last docutils">
+<dt><strong>Warning</strong></dt>
+<dd>Emits a warning if two values disagree. The result value will be the
+operand for the flag from the first module being linked.</dd>
+</dl>
+</td>
+</tr>
+<tr class="row-even"><td>3</td>
+<td><dl class="first last docutils">
+<dt><strong>Require</strong></dt>
+<dd>Adds a requirement that another module flag be present and have a
+specified value after linking is performed. The value must be a
+metadata pair, where the first element of the pair is the ID of the
+module flag to be restricted, and the second element of the pair is
+the value the module flag should be restricted to. This behavior can
+be used to restrict the allowable results (via triggering of an
+error) of linking IDs with the <strong>Override</strong> behavior.</dd>
+</dl>
+</td>
+</tr>
+<tr class="row-odd"><td>4</td>
+<td><dl class="first last docutils">
+<dt><strong>Override</strong></dt>
+<dd>Uses the specified value, regardless of the behavior or value of the
+other module. If both modules specify <strong>Override</strong>, but the values
+differ, an error will be emitted.</dd>
+</dl>
+</td>
+</tr>
+<tr class="row-even"><td>5</td>
+<td><dl class="first last docutils">
+<dt><strong>Append</strong></dt>
+<dd>Appends the two values, which are required to be metadata nodes.</dd>
+</dl>
+</td>
+</tr>
+<tr class="row-odd"><td>6</td>
+<td><dl class="first last docutils">
+<dt><strong>AppendUnique</strong></dt>
+<dd>Appends the two values, which are required to be metadata
+nodes. However, duplicate entries in the second list are dropped
+during the append operation.</dd>
+</dl>
+</td>
+</tr>
+</tbody>
+</table>
+<p>It is an error for a particular unique flag ID to have multiple behaviors,
+except in the case of <strong>Require</strong> (which adds restrictions on another metadata
+value) or <strong>Override</strong>.</p>
+<p>An example of module flags:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv-Anonymous">!0</span> <span class="p">=</span> <span class="p">!{</span> <span class="k">i32</span> <span class="m">1</span><span class="p">,</span> <span class="nv">!"foo"</span><span class="p">,</span> <span class="k">i32</span> <span class="m">1</span> <span class="p">}</span>
+<span class="nv-Anonymous">!1</span> <span class="p">=</span> <span class="p">!{</span> <span class="k">i32</span> <span class="m">4</span><span class="p">,</span> <span class="nv">!"bar"</span><span class="p">,</span> <span class="k">i32</span> <span class="m">37</span> <span class="p">}</span>
+<span class="nv-Anonymous">!2</span> <span class="p">=</span> <span class="p">!{</span> <span class="k">i32</span> <span class="m">2</span><span class="p">,</span> <span class="nv">!"qux"</span><span class="p">,</span> <span class="k">i32</span> <span class="m">42</span> <span class="p">}</span>
+<span class="nv-Anonymous">!3</span> <span class="p">=</span> <span class="p">!{</span> <span class="k">i32</span> <span class="m">3</span><span class="p">,</span> <span class="nv">!"qux"</span><span class="p">,</span>
+  <span class="p">!{</span>
+    <span class="nv">!"foo"</span><span class="p">,</span> <span class="k">i32</span> <span class="m">1</span>
+  <span class="p">}</span>
+<span class="p">}</span>
+<span class="nv">!llvm.module.flags</span> <span class="p">=</span> <span class="p">!{</span> <span class="nv-Anonymous">!0</span><span class="p">,</span> <span class="nv-Anonymous">!1</span><span class="p">,</span> <span class="nv-Anonymous">!2</span><span class="p">,</span> <span class="nv-Anonymous">!3</span> <span class="p">}</span>
+</pre></div>
+</div>
+<ul>
+<li><p class="first">Metadata <tt class="docutils literal"><span class="pre">!0</span></tt> has the ID <tt class="docutils literal"><span class="pre">!"foo"</span></tt> and the value ‘1’. The behavior
+if two or more <tt class="docutils literal"><span class="pre">!"foo"</span></tt> flags are seen is to emit an error if their
+values are not equal.</p>
+</li>
+<li><p class="first">Metadata <tt class="docutils literal"><span class="pre">!1</span></tt> has the ID <tt class="docutils literal"><span class="pre">!"bar"</span></tt> and the value ‘37’. The
+behavior if two or more <tt class="docutils literal"><span class="pre">!"bar"</span></tt> flags are seen is to use the value
+‘37’.</p>
+</li>
+<li><p class="first">Metadata <tt class="docutils literal"><span class="pre">!2</span></tt> has the ID <tt class="docutils literal"><span class="pre">!"qux"</span></tt> and the value ‘42’. The
+behavior if two or more <tt class="docutils literal"><span class="pre">!"qux"</span></tt> flags are seen is to emit a
+warning if their values are not equal.</p>
+</li>
+<li><p class="first">Metadata <tt class="docutils literal"><span class="pre">!3</span></tt> has the ID <tt class="docutils literal"><span class="pre">!"qux"</span></tt> and the value:</p>
+<div class="highlight-python"><div class="highlight"><pre>!{ !"foo", i32 1 }
+</pre></div>
+</div>
+<p>The behavior is to emit an error if the <tt class="docutils literal"><span class="pre">llvm.module.flags</span></tt> does not
+contain a flag with the ID <tt class="docutils literal"><span class="pre">!"foo"</span></tt> that has the value ‘1’ after linking is
+performed.</p>
+</li>
+</ul>
+<div class="section" id="objective-c-garbage-collection-module-flags-metadata">
+<h3><a class="toc-backref" href="#id659">Objective-C Garbage Collection Module Flags Metadata</a><a class="headerlink" href="#objective-c-garbage-collection-module-flags-metadata" title="Permalink to this headline">¶</a></h3>
+<p>On the Mach-O platform, Objective-C stores metadata about garbage
+collection in a special section called “image info”. The metadata
+consists of a version number and a bitmask specifying what types of
+garbage collection are supported (if any) by the file. If two or more
+modules are linked together their garbage collection metadata needs to
+be merged rather than appended together.</p>
+<p>The Objective-C garbage collection module flags metadata consists of the
+following key-value pairs:</p>
+<table border="1" class="docutils">
+<colgroup>
+<col width="30%" />
+<col width="70%" />
+</colgroup>
+<thead valign="bottom">
+<tr class="row-odd"><th class="head">Key</th>
+<th class="head">Value</th>
+</tr>
+</thead>
+<tbody valign="top">
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">Objective-C</span> <span class="pre">Version</span></tt></td>
+<td><strong>[Required]</strong> — The Objective-C ABI version. Valid values are 1 and 2.</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">Objective-C</span> <span class="pre">Image</span> <span class="pre">Info</span> <span class="pre">Version</span></tt></td>
+<td><strong>[Required]</strong> — The version of the image info section. Currently
+always 0.</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">Objective-C</span> <span class="pre">Image</span> <span class="pre">Info</span> <span class="pre">Section</span></tt></td>
+<td><strong>[Required]</strong> — The section to place the metadata. Valid values are
+<tt class="docutils literal"><span class="pre">"__OBJC,</span> <span class="pre">__image_info,</span> <span class="pre">regular"</span></tt> for Objective-C ABI version 1, and
+<tt class="docutils literal"><span class="pre">"__DATA,__objc_imageinfo,</span> <span class="pre">regular,</span> <span class="pre">no_dead_strip"</span></tt> for
+Objective-C ABI version 2.</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">Objective-C</span> <span class="pre">Garbage</span> <span class="pre">Collection</span></tt></td>
+<td><strong>[Required]</strong> — Specifies whether garbage collection is supported or
+not. Valid values are 0, for no garbage collection, and 2, for garbage
+collection supported.</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">Objective-C</span> <span class="pre">GC</span> <span class="pre">Only</span></tt></td>
+<td><strong>[Optional]</strong> — Specifies that only garbage collection is supported.
+If present, its value must be 6. This flag requires that the
+<tt class="docutils literal"><span class="pre">Objective-C</span> <span class="pre">Garbage</span> <span class="pre">Collection</span></tt> flag have the value 2.</td>
+</tr>
+</tbody>
+</table>
+<p>Some important flag interactions:</p>
+<ul class="simple">
+<li>If a module with <tt class="docutils literal"><span class="pre">Objective-C</span> <span class="pre">Garbage</span> <span class="pre">Collection</span></tt> set to 0 is
+merged with a module with <tt class="docutils literal"><span class="pre">Objective-C</span> <span class="pre">Garbage</span> <span class="pre">Collection</span></tt> set to
+2, then the resulting module has the
+<tt class="docutils literal"><span class="pre">Objective-C</span> <span class="pre">Garbage</span> <span class="pre">Collection</span></tt> flag set to 0.</li>
+<li>A module with <tt class="docutils literal"><span class="pre">Objective-C</span> <span class="pre">Garbage</span> <span class="pre">Collection</span></tt> set to 0 cannot be
+merged with a module with <tt class="docutils literal"><span class="pre">Objective-C</span> <span class="pre">GC</span> <span class="pre">Only</span></tt> set to 6.</li>
+</ul>
+</div>
+<div class="section" id="automatic-linker-flags-module-flags-metadata">
+<h3><a class="toc-backref" href="#id660">Automatic Linker Flags Module Flags Metadata</a><a class="headerlink" href="#automatic-linker-flags-module-flags-metadata" title="Permalink to this headline">¶</a></h3>
+<p>Some targets support embedding flags to the linker inside individual object
+files. Typically this is used in conjunction with language extensions which
+allow source files to explicitly declare the libraries they depend on, and have
+these automatically be transmitted to the linker via object files.</p>
+<p>These flags are encoded in the IR using metadata in the module flags section,
+using the <tt class="docutils literal"><span class="pre">Linker</span> <span class="pre">Options</span></tt> key. The merge behavior for this flag is required
+to be <tt class="docutils literal"><span class="pre">AppendUnique</span></tt>, and the value for the key is expected to be a metadata
+node which should be a list of other metadata nodes, each of which should be a
+list of metadata strings defining linker options.</p>
+<p>For example, the following metadata section specifies two separate sets of
+linker options, presumably to link against <tt class="docutils literal"><span class="pre">libz</span></tt> and the <tt class="docutils literal"><span class="pre">Cocoa</span></tt>
+framework:</p>
+<div class="highlight-python"><div class="highlight"><pre>!0 = !{ i32 6, !"Linker Options",
+   !{
+      !{ !"-lz" },
+      !{ !"-framework", !"Cocoa" } } }
+!llvm.module.flags = !{ !0 }
+</pre></div>
+</div>
+<p>The metadata encoding as lists of lists of options, as opposed to a collapsed
+list of options, is chosen so that the IR encoding can use multiple option
+strings to specify e.g., a single library, while still having that specifier be
+preserved as an atomic element that can be recognized by a target specific
+assembly writer or object file emitter.</p>
+<p>Each individual option is required to be either a valid option for the target’s
+linker, or an option that is reserved by the target specific assembly writer or
+object file emitter. No other aspect of these options is defined by the IR.</p>
+</div>
+<div class="section" id="c-type-width-module-flags-metadata">
+<h3><a class="toc-backref" href="#id661">C type width Module Flags Metadata</a><a class="headerlink" href="#c-type-width-module-flags-metadata" title="Permalink to this headline">¶</a></h3>
+<p>The ARM backend emits a section into each generated object file describing the
+options that it was compiled with (in a compiler-independent way) to prevent
+linking incompatible objects, and to allow automatic library selection. Some
+of these options are not visible at the IR level, namely wchar_t width and enum
+width.</p>
+<p>To pass this information to the backend, these options are encoded in module
+flags metadata, using the following key-value pairs:</p>
+<table border="1" class="docutils">
+<colgroup>
+<col width="30%" />
+<col width="70%" />
+</colgroup>
+<thead valign="bottom">
+<tr class="row-odd"><th class="head">Key</th>
+<th class="head">Value</th>
+</tr>
+</thead>
+<tbody valign="top">
+<tr class="row-even"><td>short_wchar</td>
+<td><ul class="first last simple">
+<li>0 — sizeof(wchar_t) == 4</li>
+<li>1 — sizeof(wchar_t) == 2</li>
+</ul>
+</td>
+</tr>
+<tr class="row-odd"><td>short_enum</td>
+<td><ul class="first last simple">
+<li>0 — Enums are at least as large as an <tt class="docutils literal"><span class="pre">int</span></tt>.</li>
+<li>1 — Enums are stored in the smallest integer type which can
+represent all of its values.</li>
+</ul>
+</td>
+</tr>
+</tbody>
+</table>
+<p>For example, the following metadata section specifies that the module was
+compiled with a <tt class="docutils literal"><span class="pre">wchar_t</span></tt> width of 4 bytes, and the underlying type of an
+enum is the smallest type which can represent all of its values:</p>
+<div class="highlight-python"><div class="highlight"><pre>!llvm.module.flags = !{!0, !1}
+!0 = !{i32 1, !"short_wchar", i32 1}
+!1 = !{i32 1, !"short_enum", i32 0}
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="intrinsic-global-variables">
+<span id="intrinsicglobalvariables"></span><h2><a class="toc-backref" href="#id662">Intrinsic Global Variables</a><a class="headerlink" href="#intrinsic-global-variables" title="Permalink to this headline">¶</a></h2>
+<p>LLVM has a number of “magic” global variables that contain data that
+affect code generation or other IR semantics. These are documented here.
+All globals of this sort should have a section specified as
+“<tt class="docutils literal"><span class="pre">llvm.metadata</span></tt>”. This section and all globals that start with
+“<tt class="docutils literal"><span class="pre">llvm.</span></tt>” are reserved for use by LLVM.</p>
+<div class="section" id="the-llvm-used-global-variable">
+<span id="gv-llvmused"></span><h3><a class="toc-backref" href="#id663">The ‘<tt class="docutils literal"><span class="pre">llvm.used</span></tt>‘ Global Variable</a><a class="headerlink" href="#the-llvm-used-global-variable" title="Permalink to this headline">¶</a></h3>
+<p>The <tt class="docutils literal"><span class="pre">@llvm.used</span></tt> global is an array which has
+<a class="reference internal" href="#linkage-appending"><em>appending linkage</em></a>. This array contains a list of
+pointers to named global variables, functions and aliases which may optionally
+have a pointer cast formed of bitcast or getelementptr. For example, a legal
+use of it is:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="vg">@X</span> <span class="p">=</span> <span class="k">global</span> <span class="k">i8</span> <span class="m">4</span>
+<span class="vg">@Y</span> <span class="p">=</span> <span class="k">global</span> <span class="k">i32</span> <span class="m">123</span>
+
+<span class="vg">@llvm.used</span> <span class="p">=</span> <span class="k">appending</span> <span class="k">global</span> <span class="p">[</span><span class="m">2</span> <span class="k">x</span> <span class="k">i8</span><span class="p">*]</span> <span class="p">[</span>
+   <span class="k">i8</span><span class="p">*</span> <span class="vg">@X</span><span class="p">,</span>
+   <span class="k">i8</span><span class="p">*</span> <span class="k">bitcast</span> <span class="p">(</span><span class="k">i32</span><span class="p">*</span> <span class="vg">@Y</span> <span class="k">to</span> <span class="k">i8</span><span class="p">*)</span>
+<span class="p">],</span> <span class="k">section</span> <span class="s">"llvm.metadata"</span>
+</pre></div>
+</div>
+<p>If a symbol appears in the <tt class="docutils literal"><span class="pre">@llvm.used</span></tt> list, then the compiler, assembler,
+and linker are required to treat the symbol as if there is a reference to the
+symbol that it cannot see (which is why they have to be named). For example, if
+a variable has internal linkage and no references other than that from the
+<tt class="docutils literal"><span class="pre">@llvm.used</span></tt> list, it cannot be deleted. This is commonly used to represent
+references from inline asms and other things the compiler cannot “see”, and
+corresponds to “<tt class="docutils literal"><span class="pre">attribute((used))</span></tt>” in GNU C.</p>
+<p>On some targets, the code generator must emit a directive to the
+assembler or object file to prevent the assembler and linker from
+molesting the symbol.</p>
+</div>
+<div class="section" id="the-llvm-compiler-used-global-variable">
+<span id="gv-llvmcompilerused"></span><h3><a class="toc-backref" href="#id664">The ‘<tt class="docutils literal"><span class="pre">llvm.compiler.used</span></tt>‘ Global Variable</a><a class="headerlink" href="#the-llvm-compiler-used-global-variable" title="Permalink to this headline">¶</a></h3>
+<p>The <tt class="docutils literal"><span class="pre">@llvm.compiler.used</span></tt> directive is the same as the <tt class="docutils literal"><span class="pre">@llvm.used</span></tt>
+directive, except that it only prevents the compiler from touching the
+symbol. On targets that support it, this allows an intelligent linker to
+optimize references to the symbol without being impeded as it would be
+by <tt class="docutils literal"><span class="pre">@llvm.used</span></tt>.</p>
+<p>This is a rare construct that should only be used in rare circumstances,
+and should not be exposed to source languages.</p>
+</div>
+<div class="section" id="the-llvm-global-ctors-global-variable">
+<span id="gv-llvmglobalctors"></span><h3><a class="toc-backref" href="#id665">The ‘<tt class="docutils literal"><span class="pre">llvm.global_ctors</span></tt>‘ Global Variable</a><a class="headerlink" href="#the-llvm-global-ctors-global-variable" title="Permalink to this headline">¶</a></h3>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv-Anonymous">%0</span> <span class="p">=</span> <span class="k">type</span> <span class="p">{</span> <span class="k">i32</span><span class="p">,</span> <span class="kt">void</span> <span class="p">()*,</span> <span class="k">i8</span><span class="p">*</span> <span class="p">}</span>
+<span class="vg">@llvm.global_ctors</span> <span class="p">=</span> <span class="k">appending</span> <span class="k">global</span> <span class="p">[</span><span class="m">1</span> <span class="k">x</span> <span class="nv-Anonymous">%0</span><span class="p">]</span> <span class="p">[</span><span class="nv-Anonymous">%0</span> <span class="p">{</span> <span class="k">i32</span> <span class="m">65535</span><span class="p">,</span> <span class="kt">void</span> <span class="p">()*</span> <span class="vg">@ctor</span><span class="p">,</span> <span class="k">i8</span><span class="p">*</span> <span class="vg">@data</span> <span class="p">}]</span>
+</pre></div>
+</div>
+<p>The <tt class="docutils literal"><span class="pre">@llvm.global_ctors</span></tt> array contains a list of constructor
+functions, priorities, and an optional associated global or function.
+The functions referenced by this array will be called in ascending order
+of priority (i.e. lowest first) when the module is loaded. The order of
+functions with the same priority is not defined.</p>
+<p>If the third field is present, non-null, and points to a global variable
+or function, the initializer function will only run if the associated
+data from the current module is not discarded.</p>
+</div>
+<div class="section" id="the-llvm-global-dtors-global-variable">
+<span id="llvmglobaldtors"></span><h3><a class="toc-backref" href="#id666">The ‘<tt class="docutils literal"><span class="pre">llvm.global_dtors</span></tt>‘ Global Variable</a><a class="headerlink" href="#the-llvm-global-dtors-global-variable" title="Permalink to this headline">¶</a></h3>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv-Anonymous">%0</span> <span class="p">=</span> <span class="k">type</span> <span class="p">{</span> <span class="k">i32</span><span class="p">,</span> <span class="kt">void</span> <span class="p">()*,</span> <span class="k">i8</span><span class="p">*</span> <span class="p">}</span>
+<span class="vg">@llvm.global_dtors</span> <span class="p">=</span> <span class="k">appending</span> <span class="k">global</span> <span class="p">[</span><span class="m">1</span> <span class="k">x</span> <span class="nv-Anonymous">%0</span><span class="p">]</span> <span class="p">[</span><span class="nv-Anonymous">%0</span> <span class="p">{</span> <span class="k">i32</span> <span class="m">65535</span><span class="p">,</span> <span class="kt">void</span> <span class="p">()*</span> <span class="vg">@dtor</span><span class="p">,</span> <span class="k">i8</span><span class="p">*</span> <span class="vg">@data</span> <span class="p">}]</span>
+</pre></div>
+</div>
+<p>The <tt class="docutils literal"><span class="pre">@llvm.global_dtors</span></tt> array contains a list of destructor
+functions, priorities, and an optional associated global or function.
+The functions referenced by this array will be called in descending
+order of priority (i.e. highest first) when the module is unloaded. The
+order of functions with the same priority is not defined.</p>
+<p>If the third field is present, non-null, and points to a global variable
+or function, the destructor function will only run if the associated
+data from the current module is not discarded.</p>
+</div>
+</div>
+<div class="section" id="instruction-reference">
+<h2><a class="toc-backref" href="#id667">Instruction Reference</a><a class="headerlink" href="#instruction-reference" title="Permalink to this headline">¶</a></h2>
+<p>The LLVM instruction set consists of several different classifications
+of instructions: <a class="reference internal" href="#terminators"><em>terminator instructions</em></a>, <a class="reference internal" href="#binaryops"><em>binary
+instructions</em></a>, <a class="reference internal" href="#bitwiseops"><em>bitwise binary
+instructions</em></a>, <a class="reference internal" href="#memoryops"><em>memory instructions</em></a>, and
+<a class="reference internal" href="#otherops"><em>other instructions</em></a>.</p>
+<div class="section" id="terminator-instructions">
+<span id="terminators"></span><h3><a class="toc-backref" href="#id668">Terminator Instructions</a><a class="headerlink" href="#terminator-instructions" title="Permalink to this headline">¶</a></h3>
+<p>As mentioned <a class="reference internal" href="#functionstructure"><em>previously</em></a>, every basic block in a
+program ends with a “Terminator” instruction, which indicates which
+block should be executed after the current block is finished. These
+terminator instructions typically yield a ‘<tt class="docutils literal"><span class="pre">void</span></tt>‘ value: they produce
+control flow, not values (the one exception being the
+‘<a class="reference internal" href="#i-invoke"><em>invoke</em></a>‘ instruction).</p>
+<p>The terminator instructions are: ‘<a class="reference internal" href="#i-ret"><em>ret</em></a>‘,
+‘<a class="reference internal" href="#i-br"><em>br</em></a>‘, ‘<a class="reference internal" href="#i-switch"><em>switch</em></a>‘,
+‘<a class="reference internal" href="#i-indirectbr"><em>indirectbr</em></a>‘, ‘<a class="reference internal" href="#i-invoke"><em>invoke</em></a>‘,
+‘<a class="reference internal" href="#i-resume"><em>resume</em></a>‘, and ‘<a class="reference internal" href="#i-unreachable"><em>unreachable</em></a>‘.</p>
+<div class="section" id="ret-instruction">
+<span id="i-ret"></span><h4><a class="toc-backref" href="#id669">‘<tt class="docutils literal"><span class="pre">ret</span></tt>‘ Instruction</a><a class="headerlink" href="#ret-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="syntax">
+<h5><a class="toc-backref" href="#id670">Syntax:</a><a class="headerlink" href="#syntax" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>ret <type> <value>       ; Return a value from a non-void function
+ret void                 ; Return from void function
+</pre></div>
+</div>
+</div>
+<div class="section" id="overview">
+<h5><a class="toc-backref" href="#id671">Overview:</a><a class="headerlink" href="#overview" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">ret</span></tt>‘ instruction is used to return control flow (and optionally
+a value) from a function back to the caller.</p>
+<p>There are two forms of the ‘<tt class="docutils literal"><span class="pre">ret</span></tt>‘ instruction: one that returns a
+value and then causes control flow, and one that just causes control
+flow to occur.</p>
+</div>
+<div class="section" id="arguments">
+<h5><a class="toc-backref" href="#id672">Arguments:</a><a class="headerlink" href="#arguments" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">ret</span></tt>‘ instruction optionally accepts a single argument, the
+return value. The type of the return value must be a ‘<a class="reference internal" href="#t-firstclass"><em>first
+class</em></a>‘ type.</p>
+<p>A function is not <a class="reference internal" href="#wellformed"><em>well formed</em></a> if it it has a non-void
+return type and contains a ‘<tt class="docutils literal"><span class="pre">ret</span></tt>‘ instruction with no return value or
+a return value with a type that does not match its type, or if it has a
+void return type and contains a ‘<tt class="docutils literal"><span class="pre">ret</span></tt>‘ instruction with a return
+value.</p>
+</div>
+<div class="section" id="semantics">
+<h5><a class="toc-backref" href="#id673">Semantics:</a><a class="headerlink" href="#semantics" title="Permalink to this headline">¶</a></h5>
+<p>When the ‘<tt class="docutils literal"><span class="pre">ret</span></tt>‘ instruction is executed, control flow returns back to
+the calling function’s context. If the caller is a
+“<a class="reference internal" href="#i-call"><em>call</em></a>” instruction, execution continues at the
+instruction after the call. If the caller was an
+“<a class="reference internal" href="#i-invoke"><em>invoke</em></a>” instruction, execution continues at the
+beginning of the “normal” destination block. If the instruction returns
+a value, that value shall set the call or invoke instruction’s return
+value.</p>
+</div>
+<div class="section" id="example">
+<h5><a class="toc-backref" href="#id674">Example:</a><a class="headerlink" href="#example" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="k">ret</span> <span class="k">i32</span> <span class="m">5</span>                       <span class="c">; Return an integer value of 5</span>
+<span class="k">ret</span> <span class="kt">void</span>                        <span class="c">; Return from a void function</span>
+<span class="k">ret</span> <span class="p">{</span> <span class="k">i32</span><span class="p">,</span> <span class="k">i8</span> <span class="p">}</span> <span class="p">{</span> <span class="k">i32</span> <span class="m">4</span><span class="p">,</span> <span class="k">i8</span> <span class="m">2</span> <span class="p">}</span> <span class="c">; Return a struct of values 4 and 2</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="br-instruction">
+<span id="i-br"></span><h4><a class="toc-backref" href="#id675">‘<tt class="docutils literal"><span class="pre">br</span></tt>‘ Instruction</a><a class="headerlink" href="#br-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id5">
+<h5><a class="toc-backref" href="#id676">Syntax:</a><a class="headerlink" href="#id5" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>br i1 <cond>, label <iftrue>, label <iffalse>
+br label <dest>          ; Unconditional branch
+</pre></div>
+</div>
+</div>
+<div class="section" id="id6">
+<h5><a class="toc-backref" href="#id677">Overview:</a><a class="headerlink" href="#id6" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">br</span></tt>‘ instruction is used to cause control flow to transfer to a
+different basic block in the current function. There are two forms of
+this instruction, corresponding to a conditional branch and an
+unconditional branch.</p>
+</div>
+<div class="section" id="id7">
+<h5><a class="toc-backref" href="#id678">Arguments:</a><a class="headerlink" href="#id7" title="Permalink to this headline">¶</a></h5>
+<p>The conditional branch form of the ‘<tt class="docutils literal"><span class="pre">br</span></tt>‘ instruction takes a single
+‘<tt class="docutils literal"><span class="pre">i1</span></tt>‘ value and two ‘<tt class="docutils literal"><span class="pre">label</span></tt>‘ values. The unconditional form of the
+‘<tt class="docutils literal"><span class="pre">br</span></tt>‘ instruction takes a single ‘<tt class="docutils literal"><span class="pre">label</span></tt>‘ value as a target.</p>
+</div>
+<div class="section" id="id8">
+<h5><a class="toc-backref" href="#id679">Semantics:</a><a class="headerlink" href="#id8" title="Permalink to this headline">¶</a></h5>
+<p>Upon execution of a conditional ‘<tt class="docutils literal"><span class="pre">br</span></tt>‘ instruction, the ‘<tt class="docutils literal"><span class="pre">i1</span></tt>‘
+argument is evaluated. If the value is <tt class="docutils literal"><span class="pre">true</span></tt>, control flows to the
+‘<tt class="docutils literal"><span class="pre">iftrue</span></tt>‘ <tt class="docutils literal"><span class="pre">label</span></tt> argument. If “cond” is <tt class="docutils literal"><span class="pre">false</span></tt>, control flows
+to the ‘<tt class="docutils literal"><span class="pre">iffalse</span></tt>‘ <tt class="docutils literal"><span class="pre">label</span></tt> argument.</p>
+</div>
+<div class="section" id="id9">
+<h5><a class="toc-backref" href="#id680">Example:</a><a class="headerlink" href="#id9" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nl">Test:</span>
+  <span class="nv">%cond</span> <span class="p">=</span> <span class="k">icmp</span> <span class="k">eq</span> <span class="k">i32</span> <span class="nv">%a</span><span class="p">,</span> <span class="nv">%b</span>
+  <span class="k">br</span> <span class="k">i1</span> <span class="nv">%cond</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%IfEqual</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%IfUnequal</span>
+<span class="nl">IfEqual:</span>
+  <span class="k">ret</span> <span class="k">i32</span> <span class="m">1</span>
+<span class="nl">IfUnequal:</span>
+  <span class="k">ret</span> <span class="k">i32</span> <span class="m">0</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="switch-instruction">
+<span id="i-switch"></span><h4><a class="toc-backref" href="#id681">‘<tt class="docutils literal"><span class="pre">switch</span></tt>‘ Instruction</a><a class="headerlink" href="#switch-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id10">
+<h5><a class="toc-backref" href="#id682">Syntax:</a><a class="headerlink" href="#id10" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
+</pre></div>
+</div>
+</div>
+<div class="section" id="id11">
+<h5><a class="toc-backref" href="#id683">Overview:</a><a class="headerlink" href="#id11" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">switch</span></tt>‘ instruction is used to transfer control flow to one of
+several different places. It is a generalization of the ‘<tt class="docutils literal"><span class="pre">br</span></tt>‘
+instruction, allowing a branch to occur to one of many possible
+destinations.</p>
+</div>
+<div class="section" id="id12">
+<h5><a class="toc-backref" href="#id684">Arguments:</a><a class="headerlink" href="#id12" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">switch</span></tt>‘ instruction uses three parameters: an integer
+comparison value ‘<tt class="docutils literal"><span class="pre">value</span></tt>‘, a default ‘<tt class="docutils literal"><span class="pre">label</span></tt>‘ destination, and an
+array of pairs of comparison value constants and ‘<tt class="docutils literal"><span class="pre">label</span></tt>‘s. The table
+is not allowed to contain duplicate constant entries.</p>
+</div>
+<div class="section" id="id13">
+<h5><a class="toc-backref" href="#id685">Semantics:</a><a class="headerlink" href="#id13" title="Permalink to this headline">¶</a></h5>
+<p>The <tt class="docutils literal"><span class="pre">switch</span></tt> instruction specifies a table of values and destinations.
+When the ‘<tt class="docutils literal"><span class="pre">switch</span></tt>‘ instruction is executed, this table is searched
+for the given value. If the value is found, control flow is transferred
+to the corresponding destination; otherwise, control flow is transferred
+to the default destination.</p>
+</div>
+<div class="section" id="implementation">
+<h5><a class="toc-backref" href="#id686">Implementation:</a><a class="headerlink" href="#implementation" title="Permalink to this headline">¶</a></h5>
+<p>Depending on properties of the target machine and the particular
+<tt class="docutils literal"><span class="pre">switch</span></tt> instruction, this instruction may be code generated in
+different ways. For example, it could be generated as a series of
+chained conditional branches or with a lookup table.</p>
+</div>
+<div class="section" id="id14">
+<h5><a class="toc-backref" href="#id687">Example:</a><a class="headerlink" href="#id14" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="c">; Emulate a conditional br instruction</span>
+<span class="nv">%Val</span> <span class="p">=</span> <span class="k">zext</span> <span class="k">i1</span> <span class="nv">%value</span> <span class="k">to</span> <span class="k">i32</span>
+<span class="k">switch</span> <span class="k">i32</span> <span class="nv">%Val</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%truedest</span> <span class="p">[</span> <span class="k">i32</span> <span class="m">0</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%falsedest</span> <span class="p">]</span>
+
+<span class="c">; Emulate an unconditional br instruction</span>
+<span class="k">switch</span> <span class="k">i32</span> <span class="m">0</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%dest</span> <span class="p">[</span> <span class="p">]</span>
+
+<span class="c">; Implement a jump table:</span>
+<span class="k">switch</span> <span class="k">i32</span> <span class="nv">%val</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%otherwise</span> <span class="p">[</span> <span class="k">i32</span> <span class="m">0</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%onzero</span>
+                                    <span class="k">i32</span> <span class="m">1</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%onone</span>
+                                    <span class="k">i32</span> <span class="m">2</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%ontwo</span> <span class="p">]</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="indirectbr-instruction">
+<span id="i-indirectbr"></span><h4><a class="toc-backref" href="#id688">‘<tt class="docutils literal"><span class="pre">indirectbr</span></tt>‘ Instruction</a><a class="headerlink" href="#indirectbr-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id15">
+<h5><a class="toc-backref" href="#id689">Syntax:</a><a class="headerlink" href="#id15" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>indirectbr <somety>* <address>, [ label <dest1>, label <dest2>, ... ]
+</pre></div>
+</div>
+</div>
+<div class="section" id="id16">
+<h5><a class="toc-backref" href="#id690">Overview:</a><a class="headerlink" href="#id16" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">indirectbr</span></tt>‘ instruction implements an indirect branch to a
+label within the current function, whose address is specified by
+“<tt class="docutils literal"><span class="pre">address</span></tt>”. Address must be derived from a
+<a class="reference internal" href="#blockaddress"><em>blockaddress</em></a> constant.</p>
+</div>
+<div class="section" id="id17">
+<h5><a class="toc-backref" href="#id691">Arguments:</a><a class="headerlink" href="#id17" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">address</span></tt>‘ argument is the address of the label to jump to. The
+rest of the arguments indicate the full set of possible destinations
+that the address may point to. Blocks are allowed to occur multiple
+times in the destination list, though this isn’t particularly useful.</p>
+<p>This destination list is required so that dataflow analysis has an
+accurate understanding of the CFG.</p>
+</div>
+<div class="section" id="id18">
+<h5><a class="toc-backref" href="#id692">Semantics:</a><a class="headerlink" href="#id18" title="Permalink to this headline">¶</a></h5>
+<p>Control transfers to the block specified in the address argument. All
+possible destination blocks must be listed in the label list, otherwise
+this instruction has undefined behavior. This implies that jumps to
+labels defined in other functions have undefined behavior as well.</p>
+</div>
+<div class="section" id="id19">
+<h5><a class="toc-backref" href="#id693">Implementation:</a><a class="headerlink" href="#id19" title="Permalink to this headline">¶</a></h5>
+<p>This is typically implemented with a jump through a register.</p>
+</div>
+<div class="section" id="id20">
+<h5><a class="toc-backref" href="#id694">Example:</a><a class="headerlink" href="#id20" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre>indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="invoke-instruction">
+<span id="i-invoke"></span><h4><a class="toc-backref" href="#id695">‘<tt class="docutils literal"><span class="pre">invoke</span></tt>‘ Instruction</a><a class="headerlink" href="#invoke-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id21">
+<h5><a class="toc-backref" href="#id696">Syntax:</a><a class="headerlink" href="#id21" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = invoke [cconv] [ret attrs] <ptr to function ty> <function ptr val>(<function args>) [fn attrs]
+              to label <normal label> unwind label <exception label>
+</pre></div>
+</div>
+</div>
+<div class="section" id="id22">
+<h5><a class="toc-backref" href="#id697">Overview:</a><a class="headerlink" href="#id22" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">invoke</span></tt>‘ instruction causes control to transfer to a specified
+function, with the possibility of control flow transfer to either the
+‘<tt class="docutils literal"><span class="pre">normal</span></tt>‘ label or the ‘<tt class="docutils literal"><span class="pre">exception</span></tt>‘ label. If the callee function
+returns with the “<tt class="docutils literal"><span class="pre">ret</span></tt>” instruction, control flow will return to the
+“normal” label. If the callee (or any indirect callees) returns via the
+“<a class="reference internal" href="#i-resume"><em>resume</em></a>” instruction or other exception handling
+mechanism, control is interrupted and continued at the dynamically
+nearest “exception” label.</p>
+<p>The ‘<tt class="docutils literal"><span class="pre">exception</span></tt>‘ label is a <a class="reference external" href="ExceptionHandling.html#overview">landing
+pad</a> for the exception. As such,
+‘<tt class="docutils literal"><span class="pre">exception</span></tt>‘ label is required to have the
+“<a class="reference internal" href="#i-landingpad"><em>landingpad</em></a>” instruction, which contains the
+information about the behavior of the program after unwinding happens,
+as its first non-PHI instruction. The restrictions on the
+“<tt class="docutils literal"><span class="pre">landingpad</span></tt>” instruction’s tightly couples it to the “<tt class="docutils literal"><span class="pre">invoke</span></tt>”
+instruction, so that the important information contained within the
+“<tt class="docutils literal"><span class="pre">landingpad</span></tt>” instruction can’t be lost through normal code motion.</p>
+</div>
+<div class="section" id="id23">
+<h5><a class="toc-backref" href="#id698">Arguments:</a><a class="headerlink" href="#id23" title="Permalink to this headline">¶</a></h5>
+<p>This instruction requires several arguments:</p>
+<ol class="arabic simple">
+<li>The optional “cconv” marker indicates which <a class="reference internal" href="#callingconv"><em>calling
+convention</em></a> the call should use. If none is
+specified, the call defaults to using C calling conventions.</li>
+<li>The optional <a class="reference internal" href="#paramattrs"><em>Parameter Attributes</em></a> list for return
+values. Only ‘<tt class="docutils literal"><span class="pre">zeroext</span></tt>‘, ‘<tt class="docutils literal"><span class="pre">signext</span></tt>‘, and ‘<tt class="docutils literal"><span class="pre">inreg</span></tt>‘ attributes
+are valid here.</li>
+<li>‘<tt class="docutils literal"><span class="pre">ptr</span> <span class="pre">to</span> <span class="pre">function</span> <span class="pre">ty</span></tt>‘: shall be the signature of the pointer to
+function value being invoked. In most cases, this is a direct
+function invocation, but indirect <tt class="docutils literal"><span class="pre">invoke</span></tt>‘s are just as possible,
+branching off an arbitrary pointer to function value.</li>
+<li>‘<tt class="docutils literal"><span class="pre">function</span> <span class="pre">ptr</span> <span class="pre">val</span></tt>‘: An LLVM value containing a pointer to a
+function to be invoked.</li>
+<li>‘<tt class="docutils literal"><span class="pre">function</span> <span class="pre">args</span></tt>‘: argument list whose types match the function
+signature argument types and parameter attributes. All arguments must
+be of <a class="reference internal" href="#t-firstclass"><em>first class</em></a> type. If the function signature
+indicates the function accepts a variable number of arguments, the
+extra arguments can be specified.</li>
+<li>‘<tt class="docutils literal"><span class="pre">normal</span> <span class="pre">label</span></tt>‘: the label reached when the called function
+executes a ‘<tt class="docutils literal"><span class="pre">ret</span></tt>‘ instruction.</li>
+<li>‘<tt class="docutils literal"><span class="pre">exception</span> <span class="pre">label</span></tt>‘: the label reached when a callee returns via
+the <a class="reference internal" href="#i-resume"><em>resume</em></a> instruction or other exception handling
+mechanism.</li>
+<li>The optional <a class="reference internal" href="#fnattrs"><em>function attributes</em></a> list. Only
+‘<tt class="docutils literal"><span class="pre">noreturn</span></tt>‘, ‘<tt class="docutils literal"><span class="pre">nounwind</span></tt>‘, ‘<tt class="docutils literal"><span class="pre">readonly</span></tt>‘ and ‘<tt class="docutils literal"><span class="pre">readnone</span></tt>‘
+attributes are valid here.</li>
+</ol>
+</div>
+<div class="section" id="id24">
+<h5><a class="toc-backref" href="#id699">Semantics:</a><a class="headerlink" href="#id24" title="Permalink to this headline">¶</a></h5>
+<p>This instruction is designed to operate as a standard ‘<tt class="docutils literal"><span class="pre">call</span></tt>‘
+instruction in most regards. The primary difference is that it
+establishes an association with a label, which is used by the runtime
+library to unwind the stack.</p>
+<p>This instruction is used in languages with destructors to ensure that
+proper cleanup is performed in the case of either a <tt class="docutils literal"><span class="pre">longjmp</span></tt> or a
+thrown exception. Additionally, this is important for implementation of
+‘<tt class="docutils literal"><span class="pre">catch</span></tt>‘ clauses in high-level languages that support them.</p>
+<p>For the purposes of the SSA form, the definition of the value returned
+by the ‘<tt class="docutils literal"><span class="pre">invoke</span></tt>‘ instruction is deemed to occur on the edge from the
+current block to the “normal” label. If the callee unwinds then no
+return value is available.</p>
+</div>
+<div class="section" id="id25">
+<h5><a class="toc-backref" href="#id700">Example:</a><a class="headerlink" href="#id25" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%retval</span> <span class="p">=</span> <span class="k">invoke</span> <span class="k">i32</span> <span class="vg">@Test</span><span class="p">(</span><span class="k">i32</span> <span class="m">15</span><span class="p">)</span> <span class="k">to</span> <span class="kt">label</span> <span class="nv">%Continue</span>
+            <span class="k">unwind</span> <span class="kt">label</span> <span class="nv">%TestCleanup</span>              <span class="c">; i32:retval set</span>
+<span class="nv">%retval</span> <span class="p">=</span> <span class="k">invoke</span> <span class="k">coldcc</span> <span class="k">i32</span> <span class="nv">%Testfnptr</span><span class="p">(</span><span class="k">i32</span> <span class="m">15</span><span class="p">)</span> <span class="k">to</span> <span class="kt">label</span> <span class="nv">%Continue</span>
+            <span class="k">unwind</span> <span class="kt">label</span> <span class="nv">%TestCleanup</span>              <span class="c">; i32:retval set</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="resume-instruction">
+<span id="i-resume"></span><h4><a class="toc-backref" href="#id701">‘<tt class="docutils literal"><span class="pre">resume</span></tt>‘ Instruction</a><a class="headerlink" href="#resume-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id26">
+<h5><a class="toc-backref" href="#id702">Syntax:</a><a class="headerlink" href="#id26" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>resume <type> <value>
+</pre></div>
+</div>
+</div>
+<div class="section" id="id27">
+<h5><a class="toc-backref" href="#id703">Overview:</a><a class="headerlink" href="#id27" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">resume</span></tt>‘ instruction is a terminator instruction that has no
+successors.</p>
+</div>
+<div class="section" id="id28">
+<h5><a class="toc-backref" href="#id704">Arguments:</a><a class="headerlink" href="#id28" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">resume</span></tt>‘ instruction requires one argument, which must have the
+same type as the result of any ‘<tt class="docutils literal"><span class="pre">landingpad</span></tt>‘ instruction in the same
+function.</p>
+</div>
+<div class="section" id="id29">
+<h5><a class="toc-backref" href="#id705">Semantics:</a><a class="headerlink" href="#id29" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">resume</span></tt>‘ instruction resumes propagation of an existing
+(in-flight) exception whose unwinding was interrupted with a
+<a class="reference internal" href="#i-landingpad"><em>landingpad</em></a> instruction.</p>
+</div>
+<div class="section" id="id30">
+<h5><a class="toc-backref" href="#id706">Example:</a><a class="headerlink" href="#id30" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre>resume { i8*, i32 } %exn
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="unreachable-instruction">
+<span id="i-unreachable"></span><h4><a class="toc-backref" href="#id707">‘<tt class="docutils literal"><span class="pre">unreachable</span></tt>‘ Instruction</a><a class="headerlink" href="#unreachable-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id31">
+<h5><a class="toc-backref" href="#id708">Syntax:</a><a class="headerlink" href="#id31" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><span class="n">unreachable</span>
+</pre></div>
+</div>
+</div>
+<div class="section" id="id32">
+<h5><a class="toc-backref" href="#id709">Overview:</a><a class="headerlink" href="#id32" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">unreachable</span></tt>‘ instruction has no defined semantics. This
+instruction is used to inform the optimizer that a particular portion of
+the code is not reachable. This can be used to indicate that the code
+after a no-return function cannot be reached, and other facts.</p>
+</div>
+<div class="section" id="id33">
+<h5><a class="toc-backref" href="#id710">Semantics:</a><a class="headerlink" href="#id33" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">unreachable</span></tt>‘ instruction has no defined semantics.</p>
+</div>
+</div>
+</div>
+<div class="section" id="binary-operations">
+<span id="binaryops"></span><h3><a class="toc-backref" href="#id711">Binary Operations</a><a class="headerlink" href="#binary-operations" title="Permalink to this headline">¶</a></h3>
+<p>Binary operators are used to do most of the computation in a program.
+They require two operands of the same type, execute an operation on
+them, and produce a single value. The operands might represent multiple
+data, as is the case with the <a class="reference internal" href="#t-vector"><em>vector</em></a> data type. The
+result value has the same type as its operands.</p>
+<p>There are several different binary operators:</p>
+<div class="section" id="add-instruction">
+<span id="i-add"></span><h4><a class="toc-backref" href="#id712">‘<tt class="docutils literal"><span class="pre">add</span></tt>‘ Instruction</a><a class="headerlink" href="#add-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id34">
+<h5><a class="toc-backref" href="#id713">Syntax:</a><a class="headerlink" href="#id34" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = add <ty> <op1>, <op2>          ; yields ty:result
+<result> = add nuw <ty> <op1>, <op2>      ; yields ty:result
+<result> = add nsw <ty> <op1>, <op2>      ; yields ty:result
+<result> = add nuw nsw <ty> <op1>, <op2>  ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id35">
+<h5><a class="toc-backref" href="#id714">Overview:</a><a class="headerlink" href="#id35" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">add</span></tt>‘ instruction returns the sum of its two operands.</p>
+</div>
+<div class="section" id="id36">
+<h5><a class="toc-backref" href="#id715">Arguments:</a><a class="headerlink" href="#id36" title="Permalink to this headline">¶</a></h5>
+<p>The two arguments to the ‘<tt class="docutils literal"><span class="pre">add</span></tt>‘ instruction must be
+<a class="reference internal" href="#t-integer"><em>integer</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of integer values. Both
+arguments must have identical types.</p>
+</div>
+<div class="section" id="id37">
+<h5><a class="toc-backref" href="#id716">Semantics:</a><a class="headerlink" href="#id37" title="Permalink to this headline">¶</a></h5>
+<p>The value produced is the integer sum of the two operands.</p>
+<p>If the sum has unsigned overflow, the result returned is the
+mathematical result modulo 2<sup>n</sup>, where n is the bit width of
+the result.</p>
+<p>Because LLVM integers use a two’s complement representation, this
+instruction is appropriate for both signed and unsigned integers.</p>
+<p><tt class="docutils literal"><span class="pre">nuw</span></tt> and <tt class="docutils literal"><span class="pre">nsw</span></tt> stand for “No Unsigned Wrap” and “No Signed Wrap”,
+respectively. If the <tt class="docutils literal"><span class="pre">nuw</span></tt> and/or <tt class="docutils literal"><span class="pre">nsw</span></tt> keywords are present, the
+result value of the <tt class="docutils literal"><span class="pre">add</span></tt> is a <a class="reference internal" href="#poisonvalues"><em>poison value</em></a> if
+unsigned and/or signed overflow, respectively, occurs.</p>
+</div>
+<div class="section" id="id38">
+<h5><a class="toc-backref" href="#id717">Example:</a><a class="headerlink" href="#id38" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = add i32 4, %var          ; yields i32:result = 4 + %var
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="fadd-instruction">
+<span id="i-fadd"></span><h4><a class="toc-backref" href="#id718">‘<tt class="docutils literal"><span class="pre">fadd</span></tt>‘ Instruction</a><a class="headerlink" href="#fadd-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id39">
+<h5><a class="toc-backref" href="#id719">Syntax:</a><a class="headerlink" href="#id39" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = fadd [fast-math flags]* <ty> <op1>, <op2>   ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id40">
+<h5><a class="toc-backref" href="#id720">Overview:</a><a class="headerlink" href="#id40" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fadd</span></tt>‘ instruction returns the sum of its two operands.</p>
+</div>
+<div class="section" id="id41">
+<h5><a class="toc-backref" href="#id721">Arguments:</a><a class="headerlink" href="#id41" title="Permalink to this headline">¶</a></h5>
+<p>The two arguments to the ‘<tt class="docutils literal"><span class="pre">fadd</span></tt>‘ instruction must be <a class="reference internal" href="#t-floating"><em>floating
+point</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of floating point values.
+Both arguments must have identical types.</p>
+</div>
+<div class="section" id="id42">
+<h5><a class="toc-backref" href="#id722">Semantics:</a><a class="headerlink" href="#id42" title="Permalink to this headline">¶</a></h5>
+<p>The value produced is the floating point sum of the two operands. This
+instruction can also take any number of <a class="reference internal" href="#fastmath"><em>fast-math flags</em></a>,
+which are optimization hints to enable otherwise unsafe floating point
+optimizations:</p>
+</div>
+<div class="section" id="id43">
+<h5><a class="toc-backref" href="#id723">Example:</a><a class="headerlink" href="#id43" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = fadd float 4.0, %var          ; yields float:result = 4.0 + %var
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="sub-instruction">
+<h4><a class="toc-backref" href="#id724">‘<tt class="docutils literal"><span class="pre">sub</span></tt>‘ Instruction</a><a class="headerlink" href="#sub-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id44">
+<h5><a class="toc-backref" href="#id725">Syntax:</a><a class="headerlink" href="#id44" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = sub <ty> <op1>, <op2>          ; yields ty:result
+<result> = sub nuw <ty> <op1>, <op2>      ; yields ty:result
+<result> = sub nsw <ty> <op1>, <op2>      ; yields ty:result
+<result> = sub nuw nsw <ty> <op1>, <op2>  ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id45">
+<h5><a class="toc-backref" href="#id726">Overview:</a><a class="headerlink" href="#id45" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">sub</span></tt>‘ instruction returns the difference of its two operands.</p>
+<p>Note that the ‘<tt class="docutils literal"><span class="pre">sub</span></tt>‘ instruction is used to represent the ‘<tt class="docutils literal"><span class="pre">neg</span></tt>‘
+instruction present in most other intermediate representations.</p>
+</div>
+<div class="section" id="id46">
+<h5><a class="toc-backref" href="#id727">Arguments:</a><a class="headerlink" href="#id46" title="Permalink to this headline">¶</a></h5>
+<p>The two arguments to the ‘<tt class="docutils literal"><span class="pre">sub</span></tt>‘ instruction must be
+<a class="reference internal" href="#t-integer"><em>integer</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of integer values. Both
+arguments must have identical types.</p>
+</div>
+<div class="section" id="id47">
+<h5><a class="toc-backref" href="#id728">Semantics:</a><a class="headerlink" href="#id47" title="Permalink to this headline">¶</a></h5>
+<p>The value produced is the integer difference of the two operands.</p>
+<p>If the difference has unsigned overflow, the result returned is the
+mathematical result modulo 2<sup>n</sup>, where n is the bit width of
+the result.</p>
+<p>Because LLVM integers use a two’s complement representation, this
+instruction is appropriate for both signed and unsigned integers.</p>
+<p><tt class="docutils literal"><span class="pre">nuw</span></tt> and <tt class="docutils literal"><span class="pre">nsw</span></tt> stand for “No Unsigned Wrap” and “No Signed Wrap”,
+respectively. If the <tt class="docutils literal"><span class="pre">nuw</span></tt> and/or <tt class="docutils literal"><span class="pre">nsw</span></tt> keywords are present, the
+result value of the <tt class="docutils literal"><span class="pre">sub</span></tt> is a <a class="reference internal" href="#poisonvalues"><em>poison value</em></a> if
+unsigned and/or signed overflow, respectively, occurs.</p>
+</div>
+<div class="section" id="id48">
+<h5><a class="toc-backref" href="#id729">Example:</a><a class="headerlink" href="#id48" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = sub i32 4, %var          ; yields i32:result = 4 - %var
+<result> = sub i32 0, %val          ; yields i32:result = -%var
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="fsub-instruction">
+<span id="i-fsub"></span><h4><a class="toc-backref" href="#id730">‘<tt class="docutils literal"><span class="pre">fsub</span></tt>‘ Instruction</a><a class="headerlink" href="#fsub-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id49">
+<h5><a class="toc-backref" href="#id731">Syntax:</a><a class="headerlink" href="#id49" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = fsub [fast-math flags]* <ty> <op1>, <op2>   ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id50">
+<h5><a class="toc-backref" href="#id732">Overview:</a><a class="headerlink" href="#id50" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fsub</span></tt>‘ instruction returns the difference of its two operands.</p>
+<p>Note that the ‘<tt class="docutils literal"><span class="pre">fsub</span></tt>‘ instruction is used to represent the ‘<tt class="docutils literal"><span class="pre">fneg</span></tt>‘
+instruction present in most other intermediate representations.</p>
+</div>
+<div class="section" id="id51">
+<h5><a class="toc-backref" href="#id733">Arguments:</a><a class="headerlink" href="#id51" title="Permalink to this headline">¶</a></h5>
+<p>The two arguments to the ‘<tt class="docutils literal"><span class="pre">fsub</span></tt>‘ instruction must be <a class="reference internal" href="#t-floating"><em>floating
+point</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of floating point values.
+Both arguments must have identical types.</p>
+</div>
+<div class="section" id="id52">
+<h5><a class="toc-backref" href="#id734">Semantics:</a><a class="headerlink" href="#id52" title="Permalink to this headline">¶</a></h5>
+<p>The value produced is the floating point difference of the two operands.
+This instruction can also take any number of <a class="reference internal" href="#fastmath"><em>fast-math
+flags</em></a>, which are optimization hints to enable otherwise
+unsafe floating point optimizations:</p>
+</div>
+<div class="section" id="id53">
+<h5><a class="toc-backref" href="#id735">Example:</a><a class="headerlink" href="#id53" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = fsub float 4.0, %var           ; yields float:result = 4.0 - %var
+<result> = fsub float -0.0, %val          ; yields float:result = -%var
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="mul-instruction">
+<h4><a class="toc-backref" href="#id736">‘<tt class="docutils literal"><span class="pre">mul</span></tt>‘ Instruction</a><a class="headerlink" href="#mul-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id54">
+<h5><a class="toc-backref" href="#id737">Syntax:</a><a class="headerlink" href="#id54" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = mul <ty> <op1>, <op2>          ; yields ty:result
+<result> = mul nuw <ty> <op1>, <op2>      ; yields ty:result
+<result> = mul nsw <ty> <op1>, <op2>      ; yields ty:result
+<result> = mul nuw nsw <ty> <op1>, <op2>  ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id55">
+<h5><a class="toc-backref" href="#id738">Overview:</a><a class="headerlink" href="#id55" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">mul</span></tt>‘ instruction returns the product of its two operands.</p>
+</div>
+<div class="section" id="id56">
+<h5><a class="toc-backref" href="#id739">Arguments:</a><a class="headerlink" href="#id56" title="Permalink to this headline">¶</a></h5>
+<p>The two arguments to the ‘<tt class="docutils literal"><span class="pre">mul</span></tt>‘ instruction must be
+<a class="reference internal" href="#t-integer"><em>integer</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of integer values. Both
+arguments must have identical types.</p>
+</div>
+<div class="section" id="id57">
+<h5><a class="toc-backref" href="#id740">Semantics:</a><a class="headerlink" href="#id57" title="Permalink to this headline">¶</a></h5>
+<p>The value produced is the integer product of the two operands.</p>
+<p>If the result of the multiplication has unsigned overflow, the result
+returned is the mathematical result modulo 2<sup>n</sup>, where n is the
+bit width of the result.</p>
+<p>Because LLVM integers use a two’s complement representation, and the
+result is the same width as the operands, this instruction returns the
+correct result for both signed and unsigned integers. If a full product
+(e.g. <tt class="docutils literal"><span class="pre">i32</span></tt> * <tt class="docutils literal"><span class="pre">i32</span></tt> -> <tt class="docutils literal"><span class="pre">i64</span></tt>) is needed, the operands should be
+sign-extended or zero-extended as appropriate to the width of the full
+product.</p>
+<p><tt class="docutils literal"><span class="pre">nuw</span></tt> and <tt class="docutils literal"><span class="pre">nsw</span></tt> stand for “No Unsigned Wrap” and “No Signed Wrap”,
+respectively. If the <tt class="docutils literal"><span class="pre">nuw</span></tt> and/or <tt class="docutils literal"><span class="pre">nsw</span></tt> keywords are present, the
+result value of the <tt class="docutils literal"><span class="pre">mul</span></tt> is a <a class="reference internal" href="#poisonvalues"><em>poison value</em></a> if
+unsigned and/or signed overflow, respectively, occurs.</p>
+</div>
+<div class="section" id="id58">
+<h5><a class="toc-backref" href="#id741">Example:</a><a class="headerlink" href="#id58" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = mul i32 4, %var          ; yields i32:result = 4 * %var
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="fmul-instruction">
+<span id="i-fmul"></span><h4><a class="toc-backref" href="#id742">‘<tt class="docutils literal"><span class="pre">fmul</span></tt>‘ Instruction</a><a class="headerlink" href="#fmul-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id59">
+<h5><a class="toc-backref" href="#id743">Syntax:</a><a class="headerlink" href="#id59" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = fmul [fast-math flags]* <ty> <op1>, <op2>   ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id60">
+<h5><a class="toc-backref" href="#id744">Overview:</a><a class="headerlink" href="#id60" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fmul</span></tt>‘ instruction returns the product of its two operands.</p>
+</div>
+<div class="section" id="id61">
+<h5><a class="toc-backref" href="#id745">Arguments:</a><a class="headerlink" href="#id61" title="Permalink to this headline">¶</a></h5>
+<p>The two arguments to the ‘<tt class="docutils literal"><span class="pre">fmul</span></tt>‘ instruction must be <a class="reference internal" href="#t-floating"><em>floating
+point</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of floating point values.
+Both arguments must have identical types.</p>
+</div>
+<div class="section" id="id62">
+<h5><a class="toc-backref" href="#id746">Semantics:</a><a class="headerlink" href="#id62" title="Permalink to this headline">¶</a></h5>
+<p>The value produced is the floating point product of the two operands.
+This instruction can also take any number of <a class="reference internal" href="#fastmath"><em>fast-math
+flags</em></a>, which are optimization hints to enable otherwise
+unsafe floating point optimizations:</p>
+</div>
+<div class="section" id="id63">
+<h5><a class="toc-backref" href="#id747">Example:</a><a class="headerlink" href="#id63" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = fmul float 4.0, %var          ; yields float:result = 4.0 * %var
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="udiv-instruction">
+<h4><a class="toc-backref" href="#id748">‘<tt class="docutils literal"><span class="pre">udiv</span></tt>‘ Instruction</a><a class="headerlink" href="#udiv-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id64">
+<h5><a class="toc-backref" href="#id749">Syntax:</a><a class="headerlink" href="#id64" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = udiv <ty> <op1>, <op2>         ; yields ty:result
+<result> = udiv exact <ty> <op1>, <op2>   ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id65">
+<h5><a class="toc-backref" href="#id750">Overview:</a><a class="headerlink" href="#id65" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">udiv</span></tt>‘ instruction returns the quotient of its two operands.</p>
+</div>
+<div class="section" id="id66">
+<h5><a class="toc-backref" href="#id751">Arguments:</a><a class="headerlink" href="#id66" title="Permalink to this headline">¶</a></h5>
+<p>The two arguments to the ‘<tt class="docutils literal"><span class="pre">udiv</span></tt>‘ instruction must be
+<a class="reference internal" href="#t-integer"><em>integer</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of integer values. Both
+arguments must have identical types.</p>
+</div>
+<div class="section" id="id67">
+<h5><a class="toc-backref" href="#id752">Semantics:</a><a class="headerlink" href="#id67" title="Permalink to this headline">¶</a></h5>
+<p>The value produced is the unsigned integer quotient of the two operands.</p>
+<p>Note that unsigned integer division and signed integer division are
+distinct operations; for signed integer division, use ‘<tt class="docutils literal"><span class="pre">sdiv</span></tt>‘.</p>
+<p>Division by zero leads to undefined behavior.</p>
+<p>If the <tt class="docutils literal"><span class="pre">exact</span></tt> keyword is present, the result value of the <tt class="docutils literal"><span class="pre">udiv</span></tt> is
+a <a class="reference internal" href="#poisonvalues"><em>poison value</em></a> if %op1 is not a multiple of %op2 (as
+such, “((a udiv exact b) mul b) == a”).</p>
+</div>
+<div class="section" id="id68">
+<h5><a class="toc-backref" href="#id753">Example:</a><a class="headerlink" href="#id68" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = udiv i32 4, %var          ; yields i32:result = 4 / %var
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="sdiv-instruction">
+<h4><a class="toc-backref" href="#id754">‘<tt class="docutils literal"><span class="pre">sdiv</span></tt>‘ Instruction</a><a class="headerlink" href="#sdiv-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id69">
+<h5><a class="toc-backref" href="#id755">Syntax:</a><a class="headerlink" href="#id69" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = sdiv <ty> <op1>, <op2>         ; yields ty:result
+<result> = sdiv exact <ty> <op1>, <op2>   ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id70">
+<h5><a class="toc-backref" href="#id756">Overview:</a><a class="headerlink" href="#id70" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">sdiv</span></tt>‘ instruction returns the quotient of its two operands.</p>
+</div>
+<div class="section" id="id71">
+<h5><a class="toc-backref" href="#id757">Arguments:</a><a class="headerlink" href="#id71" title="Permalink to this headline">¶</a></h5>
+<p>The two arguments to the ‘<tt class="docutils literal"><span class="pre">sdiv</span></tt>‘ instruction must be
+<a class="reference internal" href="#t-integer"><em>integer</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of integer values. Both
+arguments must have identical types.</p>
+</div>
+<div class="section" id="id72">
+<h5><a class="toc-backref" href="#id758">Semantics:</a><a class="headerlink" href="#id72" title="Permalink to this headline">¶</a></h5>
+<p>The value produced is the signed integer quotient of the two operands
+rounded towards zero.</p>
+<p>Note that signed integer division and unsigned integer division are
+distinct operations; for unsigned integer division, use ‘<tt class="docutils literal"><span class="pre">udiv</span></tt>‘.</p>
+<p>Division by zero leads to undefined behavior. Overflow also leads to
+undefined behavior; this is a rare case, but can occur, for example, by
+doing a 32-bit division of -2147483648 by -1.</p>
+<p>If the <tt class="docutils literal"><span class="pre">exact</span></tt> keyword is present, the result value of the <tt class="docutils literal"><span class="pre">sdiv</span></tt> is
+a <a class="reference internal" href="#poisonvalues"><em>poison value</em></a> if the result would be rounded.</p>
+</div>
+<div class="section" id="id73">
+<h5><a class="toc-backref" href="#id759">Example:</a><a class="headerlink" href="#id73" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = sdiv i32 4, %var          ; yields i32:result = 4 / %var
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="fdiv-instruction">
+<span id="i-fdiv"></span><h4><a class="toc-backref" href="#id760">‘<tt class="docutils literal"><span class="pre">fdiv</span></tt>‘ Instruction</a><a class="headerlink" href="#fdiv-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id74">
+<h5><a class="toc-backref" href="#id761">Syntax:</a><a class="headerlink" href="#id74" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = fdiv [fast-math flags]* <ty> <op1>, <op2>   ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id75">
+<h5><a class="toc-backref" href="#id762">Overview:</a><a class="headerlink" href="#id75" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fdiv</span></tt>‘ instruction returns the quotient of its two operands.</p>
+</div>
+<div class="section" id="id76">
+<h5><a class="toc-backref" href="#id763">Arguments:</a><a class="headerlink" href="#id76" title="Permalink to this headline">¶</a></h5>
+<p>The two arguments to the ‘<tt class="docutils literal"><span class="pre">fdiv</span></tt>‘ instruction must be <a class="reference internal" href="#t-floating"><em>floating
+point</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of floating point values.
+Both arguments must have identical types.</p>
+</div>
+<div class="section" id="id77">
+<h5><a class="toc-backref" href="#id764">Semantics:</a><a class="headerlink" href="#id77" title="Permalink to this headline">¶</a></h5>
+<p>The value produced is the floating point quotient of the two operands.
+This instruction can also take any number of <a class="reference internal" href="#fastmath"><em>fast-math
+flags</em></a>, which are optimization hints to enable otherwise
+unsafe floating point optimizations:</p>
+</div>
+<div class="section" id="id78">
+<h5><a class="toc-backref" href="#id765">Example:</a><a class="headerlink" href="#id78" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = fdiv float 4.0, %var          ; yields float:result = 4.0 / %var
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="urem-instruction">
+<h4><a class="toc-backref" href="#id766">‘<tt class="docutils literal"><span class="pre">urem</span></tt>‘ Instruction</a><a class="headerlink" href="#urem-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id79">
+<h5><a class="toc-backref" href="#id767">Syntax:</a><a class="headerlink" href="#id79" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = urem <ty> <op1>, <op2>   ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id80">
+<h5><a class="toc-backref" href="#id768">Overview:</a><a class="headerlink" href="#id80" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">urem</span></tt>‘ instruction returns the remainder from the unsigned
+division of its two arguments.</p>
+</div>
+<div class="section" id="id81">
+<h5><a class="toc-backref" href="#id769">Arguments:</a><a class="headerlink" href="#id81" title="Permalink to this headline">¶</a></h5>
+<p>The two arguments to the ‘<tt class="docutils literal"><span class="pre">urem</span></tt>‘ instruction must be
+<a class="reference internal" href="#t-integer"><em>integer</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of integer values. Both
+arguments must have identical types.</p>
+</div>
+<div class="section" id="id82">
+<h5><a class="toc-backref" href="#id770">Semantics:</a><a class="headerlink" href="#id82" title="Permalink to this headline">¶</a></h5>
+<p>This instruction returns the unsigned integer <em>remainder</em> of a division.
+This instruction always performs an unsigned division to get the
+remainder.</p>
+<p>Note that unsigned integer remainder and signed integer remainder are
+distinct operations; for signed integer remainder, use ‘<tt class="docutils literal"><span class="pre">srem</span></tt>‘.</p>
+<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
+</div>
+<div class="section" id="id83">
+<h5><a class="toc-backref" href="#id771">Example:</a><a class="headerlink" href="#id83" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = urem i32 4, %var          ; yields i32:result = 4 % %var
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="srem-instruction">
+<h4><a class="toc-backref" href="#id772">‘<tt class="docutils literal"><span class="pre">srem</span></tt>‘ Instruction</a><a class="headerlink" href="#srem-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id84">
+<h5><a class="toc-backref" href="#id773">Syntax:</a><a class="headerlink" href="#id84" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = srem <ty> <op1>, <op2>   ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id85">
+<h5><a class="toc-backref" href="#id774">Overview:</a><a class="headerlink" href="#id85" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">srem</span></tt>‘ instruction returns the remainder from the signed
+division of its two operands. This instruction can also take
+<a class="reference internal" href="#t-vector"><em>vector</em></a> versions of the values in which case the elements
+must be integers.</p>
+</div>
+<div class="section" id="id86">
+<h5><a class="toc-backref" href="#id775">Arguments:</a><a class="headerlink" href="#id86" title="Permalink to this headline">¶</a></h5>
+<p>The two arguments to the ‘<tt class="docutils literal"><span class="pre">srem</span></tt>‘ instruction must be
+<a class="reference internal" href="#t-integer"><em>integer</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of integer values. Both
+arguments must have identical types.</p>
+</div>
+<div class="section" id="id87">
+<h5><a class="toc-backref" href="#id776">Semantics:</a><a class="headerlink" href="#id87" title="Permalink to this headline">¶</a></h5>
+<p>This instruction returns the <em>remainder</em> of a division (where the result
+is either zero or has the same sign as the dividend, <tt class="docutils literal"><span class="pre">op1</span></tt>), not the
+<em>modulo</em> operator (where the result is either zero or has the same sign
+as the divisor, <tt class="docutils literal"><span class="pre">op2</span></tt>) of a value. For more information about the
+difference, see <a class="reference external" href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The Math
+Forum</a>. For a
+table of how this is implemented in various languages, please see
+<a class="reference external" href="http://en.wikipedia.org/wiki/Modulo_operation">Wikipedia: modulo
+operation</a>.</p>
+<p>Note that signed integer remainder and unsigned integer remainder are
+distinct operations; for unsigned integer remainder, use ‘<tt class="docutils literal"><span class="pre">urem</span></tt>‘.</p>
+<p>Taking the remainder of a division by zero leads to undefined behavior.
+Overflow also leads to undefined behavior; this is a rare case, but can
+occur, for example, by taking the remainder of a 32-bit division of
+-2147483648 by -1. (The remainder doesn’t actually overflow, but this
+rule lets srem be implemented using instructions that return both the
+result of the division and the remainder.)</p>
+</div>
+<div class="section" id="id88">
+<h5><a class="toc-backref" href="#id777">Example:</a><a class="headerlink" href="#id88" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = srem i32 4, %var          ; yields i32:result = 4 % %var
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="frem-instruction">
+<span id="i-frem"></span><h4><a class="toc-backref" href="#id778">‘<tt class="docutils literal"><span class="pre">frem</span></tt>‘ Instruction</a><a class="headerlink" href="#frem-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id89">
+<h5><a class="toc-backref" href="#id779">Syntax:</a><a class="headerlink" href="#id89" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = frem [fast-math flags]* <ty> <op1>, <op2>   ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id90">
+<h5><a class="toc-backref" href="#id780">Overview:</a><a class="headerlink" href="#id90" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">frem</span></tt>‘ instruction returns the remainder from the division of
+its two operands.</p>
+</div>
+<div class="section" id="id91">
+<h5><a class="toc-backref" href="#id781">Arguments:</a><a class="headerlink" href="#id91" title="Permalink to this headline">¶</a></h5>
+<p>The two arguments to the ‘<tt class="docutils literal"><span class="pre">frem</span></tt>‘ instruction must be <a class="reference internal" href="#t-floating"><em>floating
+point</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of floating point values.
+Both arguments must have identical types.</p>
+</div>
+<div class="section" id="id92">
+<h5><a class="toc-backref" href="#id782">Semantics:</a><a class="headerlink" href="#id92" title="Permalink to this headline">¶</a></h5>
+<p>This instruction returns the <em>remainder</em> of a division. The remainder
+has the same sign as the dividend. This instruction can also take any
+number of <a class="reference internal" href="#fastmath"><em>fast-math flags</em></a>, which are optimization hints
+to enable otherwise unsafe floating point optimizations:</p>
+</div>
+<div class="section" id="id93">
+<h5><a class="toc-backref" href="#id783">Example:</a><a class="headerlink" href="#id93" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = frem float 4.0, %var          ; yields float:result = 4.0 % %var
+</pre></div>
+</div>
+</div>
+</div>
+</div>
+<div class="section" id="bitwise-binary-operations">
+<span id="bitwiseops"></span><h3><a class="toc-backref" href="#id784">Bitwise Binary Operations</a><a class="headerlink" href="#bitwise-binary-operations" title="Permalink to this headline">¶</a></h3>
+<p>Bitwise binary operators are used to do various forms of bit-twiddling
+in a program. They are generally very efficient instructions and can
+commonly be strength reduced from other instructions. They require two
+operands of the same type, execute an operation on them, and produce a
+single value. The resulting value is the same type as its operands.</p>
+<div class="section" id="shl-instruction">
+<h4><a class="toc-backref" href="#id785">‘<tt class="docutils literal"><span class="pre">shl</span></tt>‘ Instruction</a><a class="headerlink" href="#shl-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id94">
+<h5><a class="toc-backref" href="#id786">Syntax:</a><a class="headerlink" href="#id94" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = shl <ty> <op1>, <op2>           ; yields ty:result
+<result> = shl nuw <ty> <op1>, <op2>       ; yields ty:result
+<result> = shl nsw <ty> <op1>, <op2>       ; yields ty:result
+<result> = shl nuw nsw <ty> <op1>, <op2>   ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id95">
+<h5><a class="toc-backref" href="#id787">Overview:</a><a class="headerlink" href="#id95" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">shl</span></tt>‘ instruction returns the first operand shifted to the left
+a specified number of bits.</p>
+</div>
+<div class="section" id="id96">
+<h5><a class="toc-backref" href="#id788">Arguments:</a><a class="headerlink" href="#id96" title="Permalink to this headline">¶</a></h5>
+<p>Both arguments to the ‘<tt class="docutils literal"><span class="pre">shl</span></tt>‘ instruction must be the same
+<a class="reference internal" href="#t-integer"><em>integer</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of integer type.
+‘<tt class="docutils literal"><span class="pre">op2</span></tt>‘ is treated as an unsigned value.</p>
+</div>
+<div class="section" id="id97">
+<h5><a class="toc-backref" href="#id789">Semantics:</a><a class="headerlink" href="#id97" title="Permalink to this headline">¶</a></h5>
+<p>The value produced is <tt class="docutils literal"><span class="pre">op1</span></tt> * 2<sup>op2</sup> mod 2<sup>n</sup>,
+where <tt class="docutils literal"><span class="pre">n</span></tt> is the width of the result. If <tt class="docutils literal"><span class="pre">op2</span></tt> is (statically or
+dynamically) negative or equal to or larger than the number of bits in
+<tt class="docutils literal"><span class="pre">op1</span></tt>, the result is undefined. If the arguments are vectors, each
+vector element of <tt class="docutils literal"><span class="pre">op1</span></tt> is shifted by the corresponding shift amount
+in <tt class="docutils literal"><span class="pre">op2</span></tt>.</p>
+<p>If the <tt class="docutils literal"><span class="pre">nuw</span></tt> keyword is present, then the shift produces a <a class="reference internal" href="#poisonvalues"><em>poison
+value</em></a> if it shifts out any non-zero bits. If the
+<tt class="docutils literal"><span class="pre">nsw</span></tt> keyword is present, then the shift produces a <a class="reference internal" href="#poisonvalues"><em>poison
+value</em></a> if it shifts out any bits that disagree with the
+resultant sign bit. As such, NUW/NSW have the same semantics as they
+would if the shift were expressed as a mul instruction with the same
+nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
+</div>
+<div class="section" id="id98">
+<h5><a class="toc-backref" href="#id790">Example:</a><a class="headerlink" href="#id98" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = shl i32 4, %var   ; yields i32: 4 << %var
+<result> = shl i32 4, 2      ; yields i32: 16
+<result> = shl i32 1, 10     ; yields i32: 1024
+<result> = shl i32 1, 32     ; undefined
+<result> = shl <2 x i32> < i32 1, i32 1>, < i32 1, i32 2>   ; yields: result=<2 x i32> < i32 2, i32 4>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="lshr-instruction">
+<h4><a class="toc-backref" href="#id791">‘<tt class="docutils literal"><span class="pre">lshr</span></tt>‘ Instruction</a><a class="headerlink" href="#lshr-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id99">
+<h5><a class="toc-backref" href="#id792">Syntax:</a><a class="headerlink" href="#id99" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = lshr <ty> <op1>, <op2>         ; yields ty:result
+<result> = lshr exact <ty> <op1>, <op2>   ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id100">
+<h5><a class="toc-backref" href="#id793">Overview:</a><a class="headerlink" href="#id100" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">lshr</span></tt>‘ instruction (logical shift right) returns the first
+operand shifted to the right a specified number of bits with zero fill.</p>
+</div>
+<div class="section" id="id101">
+<h5><a class="toc-backref" href="#id794">Arguments:</a><a class="headerlink" href="#id101" title="Permalink to this headline">¶</a></h5>
+<p>Both arguments to the ‘<tt class="docutils literal"><span class="pre">lshr</span></tt>‘ instruction must be the same
+<a class="reference internal" href="#t-integer"><em>integer</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of integer type.
+‘<tt class="docutils literal"><span class="pre">op2</span></tt>‘ is treated as an unsigned value.</p>
+</div>
+<div class="section" id="id102">
+<h5><a class="toc-backref" href="#id795">Semantics:</a><a class="headerlink" href="#id102" title="Permalink to this headline">¶</a></h5>
+<p>This instruction always performs a logical shift right operation. The
+most significant bits of the result will be filled with zero bits after
+the shift. If <tt class="docutils literal"><span class="pre">op2</span></tt> is (statically or dynamically) equal to or larger
+than the number of bits in <tt class="docutils literal"><span class="pre">op1</span></tt>, the result is undefined. If the
+arguments are vectors, each vector element of <tt class="docutils literal"><span class="pre">op1</span></tt> is shifted by the
+corresponding shift amount in <tt class="docutils literal"><span class="pre">op2</span></tt>.</p>
+<p>If the <tt class="docutils literal"><span class="pre">exact</span></tt> keyword is present, the result value of the <tt class="docutils literal"><span class="pre">lshr</span></tt> is
+a <a class="reference internal" href="#poisonvalues"><em>poison value</em></a> if any of the bits shifted out are
+non-zero.</p>
+</div>
+<div class="section" id="id103">
+<h5><a class="toc-backref" href="#id796">Example:</a><a class="headerlink" href="#id103" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = lshr i32 4, 1   ; yields i32:result = 2
+<result> = lshr i32 4, 2   ; yields i32:result = 1
+<result> = lshr i8  4, 3   ; yields i8:result = 0
+<result> = lshr i8 -2, 1   ; yields i8:result = 0x7F
+<result> = lshr i32 1, 32  ; undefined
+<result> = lshr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 2>   ; yields: result=<2 x i32> < i32 0x7FFFFFFF, i32 1>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="ashr-instruction">
+<h4><a class="toc-backref" href="#id797">‘<tt class="docutils literal"><span class="pre">ashr</span></tt>‘ Instruction</a><a class="headerlink" href="#ashr-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id104">
+<h5><a class="toc-backref" href="#id798">Syntax:</a><a class="headerlink" href="#id104" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = ashr <ty> <op1>, <op2>         ; yields ty:result
+<result> = ashr exact <ty> <op1>, <op2>   ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id105">
+<h5><a class="toc-backref" href="#id799">Overview:</a><a class="headerlink" href="#id105" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">ashr</span></tt>‘ instruction (arithmetic shift right) returns the first
+operand shifted to the right a specified number of bits with sign
+extension.</p>
+</div>
+<div class="section" id="id106">
+<h5><a class="toc-backref" href="#id800">Arguments:</a><a class="headerlink" href="#id106" title="Permalink to this headline">¶</a></h5>
+<p>Both arguments to the ‘<tt class="docutils literal"><span class="pre">ashr</span></tt>‘ instruction must be the same
+<a class="reference internal" href="#t-integer"><em>integer</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of integer type.
+‘<tt class="docutils literal"><span class="pre">op2</span></tt>‘ is treated as an unsigned value.</p>
+</div>
+<div class="section" id="id107">
+<h5><a class="toc-backref" href="#id801">Semantics:</a><a class="headerlink" href="#id107" title="Permalink to this headline">¶</a></h5>
+<p>This instruction always performs an arithmetic shift right operation,
+The most significant bits of the result will be filled with the sign bit
+of <tt class="docutils literal"><span class="pre">op1</span></tt>. If <tt class="docutils literal"><span class="pre">op2</span></tt> is (statically or dynamically) equal to or larger
+than the number of bits in <tt class="docutils literal"><span class="pre">op1</span></tt>, the result is undefined. If the
+arguments are vectors, each vector element of <tt class="docutils literal"><span class="pre">op1</span></tt> is shifted by the
+corresponding shift amount in <tt class="docutils literal"><span class="pre">op2</span></tt>.</p>
+<p>If the <tt class="docutils literal"><span class="pre">exact</span></tt> keyword is present, the result value of the <tt class="docutils literal"><span class="pre">ashr</span></tt> is
+a <a class="reference internal" href="#poisonvalues"><em>poison value</em></a> if any of the bits shifted out are
+non-zero.</p>
+</div>
+<div class="section" id="id108">
+<h5><a class="toc-backref" href="#id802">Example:</a><a class="headerlink" href="#id108" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = ashr i32 4, 1   ; yields i32:result = 2
+<result> = ashr i32 4, 2   ; yields i32:result = 1
+<result> = ashr i8  4, 3   ; yields i8:result = 0
+<result> = ashr i8 -2, 1   ; yields i8:result = -1
+<result> = ashr i32 1, 32  ; undefined
+<result> = ashr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 3>   ; yields: result=<2 x i32> < i32 -1, i32 0>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="and-instruction">
+<h4><a class="toc-backref" href="#id803">‘<tt class="docutils literal"><span class="pre">and</span></tt>‘ Instruction</a><a class="headerlink" href="#and-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id109">
+<h5><a class="toc-backref" href="#id804">Syntax:</a><a class="headerlink" href="#id109" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = and <ty> <op1>, <op2>   ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id110">
+<h5><a class="toc-backref" href="#id805">Overview:</a><a class="headerlink" href="#id110" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">and</span></tt>‘ instruction returns the bitwise logical and of its two
+operands.</p>
+</div>
+<div class="section" id="id111">
+<h5><a class="toc-backref" href="#id806">Arguments:</a><a class="headerlink" href="#id111" title="Permalink to this headline">¶</a></h5>
+<p>The two arguments to the ‘<tt class="docutils literal"><span class="pre">and</span></tt>‘ instruction must be
+<a class="reference internal" href="#t-integer"><em>integer</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of integer values. Both
+arguments must have identical types.</p>
+</div>
+<div class="section" id="id112">
+<h5><a class="toc-backref" href="#id807">Semantics:</a><a class="headerlink" href="#id112" title="Permalink to this headline">¶</a></h5>
+<p>The truth table used for the ‘<tt class="docutils literal"><span class="pre">and</span></tt>‘ instruction is:</p>
+<table border="1" class="docutils">
+<colgroup>
+<col width="33%" />
+<col width="33%" />
+<col width="33%" />
+</colgroup>
+<tbody valign="top">
+<tr class="row-odd"><td>In0</td>
+<td>In1</td>
+<td>Out</td>
+</tr>
+<tr class="row-even"><td>0</td>
+<td>0</td>
+<td>0</td>
+</tr>
+<tr class="row-odd"><td>0</td>
+<td>1</td>
+<td>0</td>
+</tr>
+<tr class="row-even"><td>1</td>
+<td>0</td>
+<td>0</td>
+</tr>
+<tr class="row-odd"><td>1</td>
+<td>1</td>
+<td>1</td>
+</tr>
+</tbody>
+</table>
+</div>
+<div class="section" id="id113">
+<h5><a class="toc-backref" href="#id808">Example:</a><a class="headerlink" href="#id113" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = and i32 4, %var         ; yields i32:result = 4 & %var
+<result> = and i32 15, 40          ; yields i32:result = 8
+<result> = and i32 4, 8            ; yields i32:result = 0
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="or-instruction">
+<h4><a class="toc-backref" href="#id809">‘<tt class="docutils literal"><span class="pre">or</span></tt>‘ Instruction</a><a class="headerlink" href="#or-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id114">
+<h5><a class="toc-backref" href="#id810">Syntax:</a><a class="headerlink" href="#id114" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = or <ty> <op1>, <op2>   ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id115">
+<h5><a class="toc-backref" href="#id811">Overview:</a><a class="headerlink" href="#id115" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">or</span></tt>‘ instruction returns the bitwise logical inclusive or of its
+two operands.</p>
+</div>
+<div class="section" id="id116">
+<h5><a class="toc-backref" href="#id812">Arguments:</a><a class="headerlink" href="#id116" title="Permalink to this headline">¶</a></h5>
+<p>The two arguments to the ‘<tt class="docutils literal"><span class="pre">or</span></tt>‘ instruction must be
+<a class="reference internal" href="#t-integer"><em>integer</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of integer values. Both
+arguments must have identical types.</p>
+</div>
+<div class="section" id="id117">
+<h5><a class="toc-backref" href="#id813">Semantics:</a><a class="headerlink" href="#id117" title="Permalink to this headline">¶</a></h5>
+<p>The truth table used for the ‘<tt class="docutils literal"><span class="pre">or</span></tt>‘ instruction is:</p>
+<table border="1" class="docutils">
+<colgroup>
+<col width="33%" />
+<col width="33%" />
+<col width="33%" />
+</colgroup>
+<tbody valign="top">
+<tr class="row-odd"><td>In0</td>
+<td>In1</td>
+<td>Out</td>
+</tr>
+<tr class="row-even"><td>0</td>
+<td>0</td>
+<td>0</td>
+</tr>
+<tr class="row-odd"><td>0</td>
+<td>1</td>
+<td>1</td>
+</tr>
+<tr class="row-even"><td>1</td>
+<td>0</td>
+<td>1</td>
+</tr>
+<tr class="row-odd"><td>1</td>
+<td>1</td>
+<td>1</td>
+</tr>
+</tbody>
+</table>
+</div>
+<div class="section" id="id118">
+<h5><a class="toc-backref" href="#id814">Example:</a><a class="headerlink" href="#id118" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = or i32 4, %var         ; yields i32:result = 4 | %var
+<result> = or i32 15, 40          ; yields i32:result = 47
+<result> = or i32 4, 8            ; yields i32:result = 12
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="xor-instruction">
+<h4><a class="toc-backref" href="#id815">‘<tt class="docutils literal"><span class="pre">xor</span></tt>‘ Instruction</a><a class="headerlink" href="#xor-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id119">
+<h5><a class="toc-backref" href="#id816">Syntax:</a><a class="headerlink" href="#id119" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = xor <ty> <op1>, <op2>   ; yields ty:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id120">
+<h5><a class="toc-backref" href="#id817">Overview:</a><a class="headerlink" href="#id120" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">xor</span></tt>‘ instruction returns the bitwise logical exclusive or of
+its two operands. The <tt class="docutils literal"><span class="pre">xor</span></tt> is used to implement the “one’s
+complement” operation, which is the “~” operator in C.</p>
+</div>
+<div class="section" id="id121">
+<h5><a class="toc-backref" href="#id818">Arguments:</a><a class="headerlink" href="#id121" title="Permalink to this headline">¶</a></h5>
+<p>The two arguments to the ‘<tt class="docutils literal"><span class="pre">xor</span></tt>‘ instruction must be
+<a class="reference internal" href="#t-integer"><em>integer</em></a> or <a class="reference internal" href="#t-vector"><em>vector</em></a> of integer values. Both
+arguments must have identical types.</p>
+</div>
+<div class="section" id="id122">
+<h5><a class="toc-backref" href="#id819">Semantics:</a><a class="headerlink" href="#id122" title="Permalink to this headline">¶</a></h5>
+<p>The truth table used for the ‘<tt class="docutils literal"><span class="pre">xor</span></tt>‘ instruction is:</p>
+<table border="1" class="docutils">
+<colgroup>
+<col width="33%" />
+<col width="33%" />
+<col width="33%" />
+</colgroup>
+<tbody valign="top">
+<tr class="row-odd"><td>In0</td>
+<td>In1</td>
+<td>Out</td>
+</tr>
+<tr class="row-even"><td>0</td>
+<td>0</td>
+<td>0</td>
+</tr>
+<tr class="row-odd"><td>0</td>
+<td>1</td>
+<td>1</td>
+</tr>
+<tr class="row-even"><td>1</td>
+<td>0</td>
+<td>1</td>
+</tr>
+<tr class="row-odd"><td>1</td>
+<td>1</td>
+<td>0</td>
+</tr>
+</tbody>
+</table>
+</div>
+<div class="section" id="id123">
+<h5><a class="toc-backref" href="#id820">Example:</a><a class="headerlink" href="#id123" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = xor i32 4, %var         ; yields i32:result = 4 ^ %var
+<result> = xor i32 15, 40          ; yields i32:result = 39
+<result> = xor i32 4, 8            ; yields i32:result = 12
+<result> = xor i32 %V, -1          ; yields i32:result = ~%V
+</pre></div>
+</div>
+</div>
+</div>
+</div>
+<div class="section" id="vector-operations">
+<h3><a class="toc-backref" href="#id821">Vector Operations</a><a class="headerlink" href="#vector-operations" title="Permalink to this headline">¶</a></h3>
+<p>LLVM supports several instructions to represent vector operations in a
+target-independent manner. These instructions cover the element-access
+and vector-specific operations needed to process vectors effectively.
+While LLVM does directly support these vector operations, many
+sophisticated algorithms will want to use target-specific intrinsics to
+take full advantage of a specific target.</p>
+<div class="section" id="extractelement-instruction">
+<span id="i-extractelement"></span><h4><a class="toc-backref" href="#id822">‘<tt class="docutils literal"><span class="pre">extractelement</span></tt>‘ Instruction</a><a class="headerlink" href="#extractelement-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id124">
+<h5><a class="toc-backref" href="#id823">Syntax:</a><a class="headerlink" href="#id124" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = extractelement <n x <ty>> <val>, <ty2> <idx>  ; yields <ty>
+</pre></div>
+</div>
+</div>
+<div class="section" id="id125">
+<h5><a class="toc-backref" href="#id824">Overview:</a><a class="headerlink" href="#id125" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">extractelement</span></tt>‘ instruction extracts a single scalar element
+from a vector at a specified index.</p>
+</div>
+<div class="section" id="id126">
+<h5><a class="toc-backref" href="#id825">Arguments:</a><a class="headerlink" href="#id126" title="Permalink to this headline">¶</a></h5>
+<p>The first operand of an ‘<tt class="docutils literal"><span class="pre">extractelement</span></tt>‘ instruction is a value of
+<a class="reference internal" href="#t-vector"><em>vector</em></a> type. The second operand is an index indicating
+the position from which to extract the element. The index may be a
+variable of any integer type.</p>
+</div>
+<div class="section" id="id127">
+<h5><a class="toc-backref" href="#id826">Semantics:</a><a class="headerlink" href="#id127" title="Permalink to this headline">¶</a></h5>
+<p>The result is a scalar of the same type as the element type of <tt class="docutils literal"><span class="pre">val</span></tt>.
+Its value is the value at position <tt class="docutils literal"><span class="pre">idx</span></tt> of <tt class="docutils literal"><span class="pre">val</span></tt>. If <tt class="docutils literal"><span class="pre">idx</span></tt>
+exceeds the length of <tt class="docutils literal"><span class="pre">val</span></tt>, the results are undefined.</p>
+</div>
+<div class="section" id="id128">
+<h5><a class="toc-backref" href="#id827">Example:</a><a class="headerlink" href="#id128" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = extractelement <4 x i32> %vec, i32 0    ; yields i32
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="insertelement-instruction">
+<span id="i-insertelement"></span><h4><a class="toc-backref" href="#id828">‘<tt class="docutils literal"><span class="pre">insertelement</span></tt>‘ Instruction</a><a class="headerlink" href="#insertelement-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id129">
+<h5><a class="toc-backref" href="#id829">Syntax:</a><a class="headerlink" href="#id129" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = insertelement <n x <ty>> <val>, <ty> <elt>, <ty2> <idx>    ; yields <n x <ty>>
+</pre></div>
+</div>
+</div>
+<div class="section" id="id130">
+<h5><a class="toc-backref" href="#id830">Overview:</a><a class="headerlink" href="#id130" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">insertelement</span></tt>‘ instruction inserts a scalar element into a
+vector at a specified index.</p>
+</div>
+<div class="section" id="id131">
+<h5><a class="toc-backref" href="#id831">Arguments:</a><a class="headerlink" href="#id131" title="Permalink to this headline">¶</a></h5>
+<p>The first operand of an ‘<tt class="docutils literal"><span class="pre">insertelement</span></tt>‘ instruction is a value of
+<a class="reference internal" href="#t-vector"><em>vector</em></a> type. The second operand is a scalar value whose
+type must equal the element type of the first operand. The third operand
+is an index indicating the position at which to insert the value. The
+index may be a variable of any integer type.</p>
+</div>
+<div class="section" id="id132">
+<h5><a class="toc-backref" href="#id832">Semantics:</a><a class="headerlink" href="#id132" title="Permalink to this headline">¶</a></h5>
+<p>The result is a vector of the same type as <tt class="docutils literal"><span class="pre">val</span></tt>. Its element values
+are those of <tt class="docutils literal"><span class="pre">val</span></tt> except at position <tt class="docutils literal"><span class="pre">idx</span></tt>, where it gets the value
+<tt class="docutils literal"><span class="pre">elt</span></tt>. If <tt class="docutils literal"><span class="pre">idx</span></tt> exceeds the length of <tt class="docutils literal"><span class="pre">val</span></tt>, the results are
+undefined.</p>
+</div>
+<div class="section" id="id133">
+<h5><a class="toc-backref" href="#id833">Example:</a><a class="headerlink" href="#id133" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = insertelement <4 x i32> %vec, i32 1, i32 0    ; yields <4 x i32>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="shufflevector-instruction">
+<span id="i-shufflevector"></span><h4><a class="toc-backref" href="#id834">‘<tt class="docutils literal"><span class="pre">shufflevector</span></tt>‘ Instruction</a><a class="headerlink" href="#shufflevector-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id134">
+<h5><a class="toc-backref" href="#id835">Syntax:</a><a class="headerlink" href="#id134" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <m x i32> <mask>    ; yields <m x <ty>>
+</pre></div>
+</div>
+</div>
+<div class="section" id="id135">
+<h5><a class="toc-backref" href="#id836">Overview:</a><a class="headerlink" href="#id135" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">shufflevector</span></tt>‘ instruction constructs a permutation of elements
+from two input vectors, returning a vector with the same element type as
+the input and length that is the same as the shuffle mask.</p>
+</div>
+<div class="section" id="id136">
+<h5><a class="toc-backref" href="#id837">Arguments:</a><a class="headerlink" href="#id136" title="Permalink to this headline">¶</a></h5>
+<p>The first two operands of a ‘<tt class="docutils literal"><span class="pre">shufflevector</span></tt>‘ instruction are vectors
+with the same type. The third argument is a shuffle mask whose element
+type is always ‘i32’. The result of the instruction is a vector whose
+length is the same as the shuffle mask and whose element type is the
+same as the element type of the first two operands.</p>
+<p>The shuffle mask operand is required to be a constant vector with either
+constant integer or undef values.</p>
+</div>
+<div class="section" id="id137">
+<h5><a class="toc-backref" href="#id838">Semantics:</a><a class="headerlink" href="#id137" title="Permalink to this headline">¶</a></h5>
+<p>The elements of the two input vectors are numbered from left to right
+across both of the vectors. The shuffle mask operand specifies, for each
+element of the result vector, which element of the two input vectors the
+result element gets. The element selector may be undef (meaning “don’t
+care”) and the second operand may be undef if performing a shuffle from
+only one vector.</p>
+</div>
+<div class="section" id="id138">
+<h5><a class="toc-backref" href="#id839">Example:</a><a class="headerlink" href="#id138" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = shufflevector <4 x i32> %v1, <4 x i32> %v2,
+                        <4 x i32> <i32 0, i32 4, i32 1, i32 5>  ; yields <4 x i32>
+<result> = shufflevector <4 x i32> %v1, <4 x i32> undef,
+                        <4 x i32> <i32 0, i32 1, i32 2, i32 3>  ; yields <4 x i32> - Identity shuffle.
+<result> = shufflevector <8 x i32> %v1, <8 x i32> undef,
+                        <4 x i32> <i32 0, i32 1, i32 2, i32 3>  ; yields <4 x i32>
+<result> = shufflevector <4 x i32> %v1, <4 x i32> %v2,
+                        <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 >  ; yields <8 x i32>
+</pre></div>
+</div>
+</div>
+</div>
+</div>
+<div class="section" id="aggregate-operations">
+<h3><a class="toc-backref" href="#id840">Aggregate Operations</a><a class="headerlink" href="#aggregate-operations" title="Permalink to this headline">¶</a></h3>
+<p>LLVM supports several instructions for working with
+<a class="reference internal" href="#t-aggregate"><em>aggregate</em></a> values.</p>
+<div class="section" id="extractvalue-instruction">
+<span id="i-extractvalue"></span><h4><a class="toc-backref" href="#id841">‘<tt class="docutils literal"><span class="pre">extractvalue</span></tt>‘ Instruction</a><a class="headerlink" href="#extractvalue-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id139">
+<h5><a class="toc-backref" href="#id842">Syntax:</a><a class="headerlink" href="#id139" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
+</pre></div>
+</div>
+</div>
+<div class="section" id="id140">
+<h5><a class="toc-backref" href="#id843">Overview:</a><a class="headerlink" href="#id140" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">extractvalue</span></tt>‘ instruction extracts the value of a member field
+from an <a class="reference internal" href="#t-aggregate"><em>aggregate</em></a> value.</p>
+</div>
+<div class="section" id="id141">
+<h5><a class="toc-backref" href="#id844">Arguments:</a><a class="headerlink" href="#id141" title="Permalink to this headline">¶</a></h5>
+<p>The first operand of an ‘<tt class="docutils literal"><span class="pre">extractvalue</span></tt>‘ instruction is a value of
+<a class="reference internal" href="#t-struct"><em>struct</em></a> or <a class="reference internal" href="#t-array"><em>array</em></a> type. The operands are
+constant indices to specify which value to extract in a similar manner
+as indices in a ‘<tt class="docutils literal"><span class="pre">getelementptr</span></tt>‘ instruction.</p>
+<p>The major differences to <tt class="docutils literal"><span class="pre">getelementptr</span></tt> indexing are:</p>
+<ul class="simple">
+<li>Since the value being indexed is not a pointer, the first index is
+omitted and assumed to be zero.</li>
+<li>At least one index must be specified.</li>
+<li>Not only struct indices but also array indices must be in bounds.</li>
+</ul>
+</div>
+<div class="section" id="id142">
+<h5><a class="toc-backref" href="#id845">Semantics:</a><a class="headerlink" href="#id142" title="Permalink to this headline">¶</a></h5>
+<p>The result is the value at the position in the aggregate specified by
+the index operands.</p>
+</div>
+<div class="section" id="id143">
+<h5><a class="toc-backref" href="#id846">Example:</a><a class="headerlink" href="#id143" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = extractvalue {i32, float} %agg, 0    ; yields i32
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="insertvalue-instruction">
+<span id="i-insertvalue"></span><h4><a class="toc-backref" href="#id847">‘<tt class="docutils literal"><span class="pre">insertvalue</span></tt>‘ Instruction</a><a class="headerlink" href="#insertvalue-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id144">
+<h5><a class="toc-backref" href="#id848">Syntax:</a><a class="headerlink" href="#id144" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = insertvalue <aggregate type> <val>, <ty> <elt>, <idx>{, <idx>}*    ; yields <aggregate type>
+</pre></div>
+</div>
+</div>
+<div class="section" id="id145">
+<h5><a class="toc-backref" href="#id849">Overview:</a><a class="headerlink" href="#id145" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">insertvalue</span></tt>‘ instruction inserts a value into a member field in
+an <a class="reference internal" href="#t-aggregate"><em>aggregate</em></a> value.</p>
+</div>
+<div class="section" id="id146">
+<h5><a class="toc-backref" href="#id850">Arguments:</a><a class="headerlink" href="#id146" title="Permalink to this headline">¶</a></h5>
+<p>The first operand of an ‘<tt class="docutils literal"><span class="pre">insertvalue</span></tt>‘ instruction is a value of
+<a class="reference internal" href="#t-struct"><em>struct</em></a> or <a class="reference internal" href="#t-array"><em>array</em></a> type. The second operand is
+a first-class value to insert. The following operands are constant
+indices indicating the position at which to insert the value in a
+similar manner as indices in a ‘<tt class="docutils literal"><span class="pre">extractvalue</span></tt>‘ instruction. The value
+to insert must have the same type as the value identified by the
+indices.</p>
+</div>
+<div class="section" id="id147">
+<h5><a class="toc-backref" href="#id851">Semantics:</a><a class="headerlink" href="#id147" title="Permalink to this headline">¶</a></h5>
+<p>The result is an aggregate of the same type as <tt class="docutils literal"><span class="pre">val</span></tt>. Its value is
+that of <tt class="docutils literal"><span class="pre">val</span></tt> except that the value at the position specified by the
+indices is that of <tt class="docutils literal"><span class="pre">elt</span></tt>.</p>
+</div>
+<div class="section" id="id148">
+<h5><a class="toc-backref" href="#id852">Example:</a><a class="headerlink" href="#id148" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%agg1</span> <span class="p">=</span> <span class="k">insertvalue</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="kt">float</span><span class="p">}</span> <span class="k">undef</span><span class="p">,</span> <span class="k">i32</span> <span class="m">1</span><span class="p">,</span> <span class="m">0</span>              <span class="c">; yields {i32 1, float undef}</span>
+<span class="nv">%agg2</span> <span class="p">=</span> <span class="k">insertvalue</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="kt">float</span><span class="p">}</span> <span class="nv">%agg1</span><span class="p">,</span> <span class="kt">float</span> <span class="nv">%val</span><span class="p">,</span> <span class="m">1</span>         <span class="c">; yields {i32 1, float %val}</span>
+<span class="nv">%agg3</span> <span class="p">=</span> <span class="k">insertvalue</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="p">{</span><span class="kt">float</span><span class="p">}}</span> <span class="k">undef</span><span class="p">,</span> <span class="kt">float</span> <span class="nv">%val</span><span class="p">,</span> <span class="m">1</span><span class="p">,</span> <span class="m">0</span>    <span class="c">; yields {i32 undef, {float %val}}</span>
+</pre></div>
+</div>
+</div>
+</div>
+</div>
+<div class="section" id="memory-access-and-addressing-operations">
+<span id="memoryops"></span><h3><a class="toc-backref" href="#id853">Memory Access and Addressing Operations</a><a class="headerlink" href="#memory-access-and-addressing-operations" title="Permalink to this headline">¶</a></h3>
+<p>A key design point of an SSA-based representation is how it represents
+memory. In LLVM, no memory locations are in SSA form, which makes things
+very simple. This section describes how to read, write, and allocate
+memory in LLVM.</p>
+<div class="section" id="alloca-instruction">
+<span id="i-alloca"></span><h4><a class="toc-backref" href="#id854">‘<tt class="docutils literal"><span class="pre">alloca</span></tt>‘ Instruction</a><a class="headerlink" href="#alloca-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id149">
+<h5><a class="toc-backref" href="#id855">Syntax:</a><a class="headerlink" href="#id149" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = alloca [inalloca] <type> [, <ty> <NumElements>] [, align <alignment>]     ; yields type*:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id150">
+<h5><a class="toc-backref" href="#id856">Overview:</a><a class="headerlink" href="#id150" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">alloca</span></tt>‘ instruction allocates memory on the stack frame of the
+currently executing function, to be automatically released when this
+function returns to its caller. The object is always allocated in the
+generic address space (address space zero).</p>
+</div>
+<div class="section" id="id151">
+<h5><a class="toc-backref" href="#id857">Arguments:</a><a class="headerlink" href="#id151" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">alloca</span></tt>‘ instruction allocates <tt class="docutils literal"><span class="pre">sizeof(<type>)*NumElements</span></tt>
+bytes of memory on the runtime stack, returning a pointer of the
+appropriate type to the program. If “NumElements” is specified, it is
+the number of elements allocated, otherwise “NumElements” is defaulted
+to be one. If a constant alignment is specified, the value result of the
+allocation is guaranteed to be aligned to at least that boundary. The
+alignment may not be greater than <tt class="docutils literal"><span class="pre">1</span> <span class="pre"><<</span> <span class="pre">29</span></tt>. If not specified, or if
+zero, the target can choose to align the allocation on any convenient
+boundary compatible with the type.</p>
+<p>‘<tt class="docutils literal"><span class="pre">type</span></tt>‘ may be any sized type.</p>
+</div>
+<div class="section" id="id152">
+<h5><a class="toc-backref" href="#id858">Semantics:</a><a class="headerlink" href="#id152" title="Permalink to this headline">¶</a></h5>
+<p>Memory is allocated; a pointer is returned. The operation is undefined
+if there is insufficient stack space for the allocation. ‘<tt class="docutils literal"><span class="pre">alloca</span></tt>‘d
+memory is automatically released when the function returns. The
+‘<tt class="docutils literal"><span class="pre">alloca</span></tt>‘ instruction is commonly used to represent automatic
+variables that must have an address available. When the function returns
+(either with the <tt class="docutils literal"><span class="pre">ret</span></tt> or <tt class="docutils literal"><span class="pre">resume</span></tt> instructions), the memory is
+reclaimed. Allocating zero bytes is legal, but the result is undefined.
+The order in which memory is allocated (ie., which way the stack grows)
+is not specified.</p>
+</div>
+<div class="section" id="id153">
+<h5><a class="toc-backref" href="#id859">Example:</a><a class="headerlink" href="#id153" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%ptr</span> <span class="p">=</span> <span class="k">alloca</span> <span class="k">i32</span>                             <span class="c">; yields i32*:ptr</span>
+<span class="nv">%ptr</span> <span class="p">=</span> <span class="k">alloca</span> <span class="k">i32</span><span class="p">,</span> <span class="k">i32</span> <span class="m">4</span>                      <span class="c">; yields i32*:ptr</span>
+<span class="nv">%ptr</span> <span class="p">=</span> <span class="k">alloca</span> <span class="k">i32</span><span class="p">,</span> <span class="k">i32</span> <span class="m">4</span><span class="p">,</span> <span class="k">align</span> <span class="m">1024</span>          <span class="c">; yields i32*:ptr</span>
+<span class="nv">%ptr</span> <span class="p">=</span> <span class="k">alloca</span> <span class="k">i32</span><span class="p">,</span> <span class="k">align</span> <span class="m">1024</span>                 <span class="c">; yields i32*:ptr</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="load-instruction">
+<span id="i-load"></span><h4><a class="toc-backref" href="#id860">‘<tt class="docutils literal"><span class="pre">load</span></tt>‘ Instruction</a><a class="headerlink" href="#load-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id154">
+<h5><a class="toc-backref" href="#id861">Syntax:</a><a class="headerlink" href="#id154" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = load [volatile] <ty>* <pointer>[, align <alignment>][, !nontemporal !<index>][, !invariant.load !<index>][, !nonnull !<index>]
+<result> = load atomic [volatile] <ty>* <pointer> [singlethread] <ordering>, align <alignment>
+!<index> = !{ i32 1 }
+</pre></div>
+</div>
+</div>
+<div class="section" id="id155">
+<h5><a class="toc-backref" href="#id862">Overview:</a><a class="headerlink" href="#id155" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">load</span></tt>‘ instruction is used to read from memory.</p>
+</div>
+<div class="section" id="id156">
+<h5><a class="toc-backref" href="#id863">Arguments:</a><a class="headerlink" href="#id156" title="Permalink to this headline">¶</a></h5>
+<p>The argument to the <tt class="docutils literal"><span class="pre">load</span></tt> instruction specifies the memory address
+from which to load. The pointer must point to a <a class="reference internal" href="#t-firstclass"><em>first
+class</em></a> type. If the <tt class="docutils literal"><span class="pre">load</span></tt> is marked as <tt class="docutils literal"><span class="pre">volatile</span></tt>,
+then the optimizer is not allowed to modify the number or order of
+execution of this <tt class="docutils literal"><span class="pre">load</span></tt> with other <a class="reference internal" href="#volatile"><em>volatile
+operations</em></a>.</p>
+<p>If the <tt class="docutils literal"><span class="pre">load</span></tt> is marked as <tt class="docutils literal"><span class="pre">atomic</span></tt>, it takes an extra
+<a class="reference internal" href="#ordering"><em>ordering</em></a> and optional <tt class="docutils literal"><span class="pre">singlethread</span></tt> argument. The
+<tt class="docutils literal"><span class="pre">release</span></tt> and <tt class="docutils literal"><span class="pre">acq_rel</span></tt> orderings are not valid on <tt class="docutils literal"><span class="pre">load</span></tt>
+instructions. Atomic loads produce <a class="reference internal" href="#memmodel"><em>defined</em></a> results
+when they may see multiple atomic stores. The type of the pointee must
+be an integer type whose bit width is a power of two greater than or
+equal to eight and less than or equal to a target-specific size limit.
+<tt class="docutils literal"><span class="pre">align</span></tt> must be explicitly specified on atomic loads, and the load has
+undefined behavior if the alignment is not set to a value which is at
+least the size in bytes of the pointee. <tt class="docutils literal"><span class="pre">!nontemporal</span></tt> does not have
+any defined semantics for atomic loads.</p>
+<p>The optional constant <tt class="docutils literal"><span class="pre">align</span></tt> argument specifies the alignment of the
+operation (that is, the alignment of the memory address). A value of 0
+or an omitted <tt class="docutils literal"><span class="pre">align</span></tt> argument means that the operation has the ABI
+alignment for the target. It is the responsibility of the code emitter
+to ensure that the alignment information is correct. Overestimating the
+alignment results in undefined behavior. Underestimating the alignment
+may produce less efficient code. An alignment of 1 is always safe. The
+maximum possible alignment is <tt class="docutils literal"><span class="pre">1</span> <span class="pre"><<</span> <span class="pre">29</span></tt>.</p>
+<p>The optional <tt class="docutils literal"><span class="pre">!nontemporal</span></tt> metadata must reference a single
+metadata name <tt class="docutils literal"><span class="pre"><index></span></tt> corresponding to a metadata node with one
+<tt class="docutils literal"><span class="pre">i32</span></tt> entry of value 1. The existence of the <tt class="docutils literal"><span class="pre">!nontemporal</span></tt>
+metadata on the instruction tells the optimizer and code generator
+that this load is not expected to be reused in the cache. The code
+generator may select special instructions to save cache bandwidth, such
+as the <tt class="docutils literal"><span class="pre">MOVNT</span></tt> instruction on x86.</p>
+<p>The optional <tt class="docutils literal"><span class="pre">!invariant.load</span></tt> metadata must reference a single
+metadata name <tt class="docutils literal"><span class="pre"><index></span></tt> corresponding to a metadata node with no
+entries. The existence of the <tt class="docutils literal"><span class="pre">!invariant.load</span></tt> metadata on the
+instruction tells the optimizer and code generator that the address
+operand to this load points to memory which can be assumed unchanged.
+Being invariant does not imply that a location is dereferenceable,
+but it does imply that once the location is known dereferenceable
+its value is henceforth unchanging.</p>
+<p>The optional <tt class="docutils literal"><span class="pre">!nonnull</span></tt> metadata must reference a single
+metadata name <tt class="docutils literal"><span class="pre"><index></span></tt> corresponding to a metadata node with no
+entries. The existence of the <tt class="docutils literal"><span class="pre">!nonnull</span></tt> metadata on the
+instruction tells the optimizer that the value loaded is known to
+never be null.  This is analogous to the ‘’nonnull’’ attribute
+on parameters and return values.  This metadata can only be applied
+to loads of a pointer type.</p>
+</div>
+<div class="section" id="id157">
+<h5><a class="toc-backref" href="#id864">Semantics:</a><a class="headerlink" href="#id157" title="Permalink to this headline">¶</a></h5>
+<p>The location of memory pointed to is loaded. If the value being loaded
+is of scalar type then the number of bytes read does not exceed the
+minimum number of bytes needed to hold all bits of the type. For
+example, loading an <tt class="docutils literal"><span class="pre">i24</span></tt> reads at most three bytes. When loading a
+value of a type like <tt class="docutils literal"><span class="pre">i20</span></tt> with a size that is not an integral number
+of bytes, the result is undefined if the value was not originally
+written using a store of the same type.</p>
+</div>
+<div class="section" id="id158">
+<h5><a class="toc-backref" href="#id865">Examples:</a><a class="headerlink" href="#id158" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%ptr</span> <span class="p">=</span> <span class="k">alloca</span> <span class="k">i32</span>                               <span class="c">; yields i32*:ptr</span>
+<span class="k">store</span> <span class="k">i32</span> <span class="m">3</span><span class="p">,</span> <span class="k">i32</span><span class="p">*</span> <span class="nv">%ptr</span>                          <span class="c">; yields void</span>
+<span class="nv">%val</span> <span class="p">=</span> <span class="k">load</span> <span class="k">i32</span><span class="p">*</span> <span class="nv">%ptr</span>                           <span class="c">; yields i32:val = i32 3</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="store-instruction">
+<span id="i-store"></span><h4><a class="toc-backref" href="#id866">‘<tt class="docutils literal"><span class="pre">store</span></tt>‘ Instruction</a><a class="headerlink" href="#store-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id159">
+<h5><a class="toc-backref" href="#id867">Syntax:</a><a class="headerlink" href="#id159" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>store [volatile] <ty> <value>, <ty>* <pointer>[, align <alignment>][, !nontemporal !<index>]        ; yields void
+store atomic [volatile] <ty> <value>, <ty>* <pointer> [singlethread] <ordering>, align <alignment>  ; yields void
+</pre></div>
+</div>
+</div>
+<div class="section" id="id160">
+<h5><a class="toc-backref" href="#id868">Overview:</a><a class="headerlink" href="#id160" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">store</span></tt>‘ instruction is used to write to memory.</p>
+</div>
+<div class="section" id="id161">
+<h5><a class="toc-backref" href="#id869">Arguments:</a><a class="headerlink" href="#id161" title="Permalink to this headline">¶</a></h5>
+<p>There are two arguments to the <tt class="docutils literal"><span class="pre">store</span></tt> instruction: a value to store
+and an address at which to store it. The type of the <tt class="docutils literal"><span class="pre"><pointer></span></tt>
+operand must be a pointer to the <a class="reference internal" href="#t-firstclass"><em>first class</em></a> type of
+the <tt class="docutils literal"><span class="pre"><value></span></tt> operand. If the <tt class="docutils literal"><span class="pre">store</span></tt> is marked as <tt class="docutils literal"><span class="pre">volatile</span></tt>,
+then the optimizer is not allowed to modify the number or order of
+execution of this <tt class="docutils literal"><span class="pre">store</span></tt> with other <a class="reference internal" href="#volatile"><em>volatile
+operations</em></a>.</p>
+<p>If the <tt class="docutils literal"><span class="pre">store</span></tt> is marked as <tt class="docutils literal"><span class="pre">atomic</span></tt>, it takes an extra
+<a class="reference internal" href="#ordering"><em>ordering</em></a> and optional <tt class="docutils literal"><span class="pre">singlethread</span></tt> argument. The
+<tt class="docutils literal"><span class="pre">acquire</span></tt> and <tt class="docutils literal"><span class="pre">acq_rel</span></tt> orderings aren’t valid on <tt class="docutils literal"><span class="pre">store</span></tt>
+instructions. Atomic loads produce <a class="reference internal" href="#memmodel"><em>defined</em></a> results
+when they may see multiple atomic stores. The type of the pointee must
+be an integer type whose bit width is a power of two greater than or
+equal to eight and less than or equal to a target-specific size limit.
+<tt class="docutils literal"><span class="pre">align</span></tt> must be explicitly specified on atomic stores, and the store
+has undefined behavior if the alignment is not set to a value which is
+at least the size in bytes of the pointee. <tt class="docutils literal"><span class="pre">!nontemporal</span></tt> does not
+have any defined semantics for atomic stores.</p>
+<p>The optional constant <tt class="docutils literal"><span class="pre">align</span></tt> argument specifies the alignment of the
+operation (that is, the alignment of the memory address). A value of 0
+or an omitted <tt class="docutils literal"><span class="pre">align</span></tt> argument means that the operation has the ABI
+alignment for the target. It is the responsibility of the code emitter
+to ensure that the alignment information is correct. Overestimating the
+alignment results in undefined behavior. Underestimating the
+alignment may produce less efficient code. An alignment of 1 is always
+safe. The maximum possible alignment is <tt class="docutils literal"><span class="pre">1</span> <span class="pre"><<</span> <span class="pre">29</span></tt>.</p>
+<p>The optional <tt class="docutils literal"><span class="pre">!nontemporal</span></tt> metadata must reference a single metadata
+name <tt class="docutils literal"><span class="pre"><index></span></tt> corresponding to a metadata node with one <tt class="docutils literal"><span class="pre">i32</span></tt> entry of
+value 1. The existence of the <tt class="docutils literal"><span class="pre">!nontemporal</span></tt> metadata on the instruction
+tells the optimizer and code generator that this load is not expected to
+be reused in the cache. The code generator may select special
+instructions to save cache bandwidth, such as the MOVNT instruction on
+x86.</p>
+</div>
+<div class="section" id="id162">
+<h5><a class="toc-backref" href="#id870">Semantics:</a><a class="headerlink" href="#id162" title="Permalink to this headline">¶</a></h5>
+<p>The contents of memory are updated to contain <tt class="docutils literal"><span class="pre"><value></span></tt> at the
+location specified by the <tt class="docutils literal"><span class="pre"><pointer></span></tt> operand. If <tt class="docutils literal"><span class="pre"><value></span></tt> is
+of scalar type then the number of bytes written does not exceed the
+minimum number of bytes needed to hold all bits of the type. For
+example, storing an <tt class="docutils literal"><span class="pre">i24</span></tt> writes at most three bytes. When writing a
+value of a type like <tt class="docutils literal"><span class="pre">i20</span></tt> with a size that is not an integral number
+of bytes, it is unspecified what happens to the extra bits that do not
+belong to the type, but they will typically be overwritten.</p>
+</div>
+<div class="section" id="id163">
+<h5><a class="toc-backref" href="#id871">Example:</a><a class="headerlink" href="#id163" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%ptr</span> <span class="p">=</span> <span class="k">alloca</span> <span class="k">i32</span>                               <span class="c">; yields i32*:ptr</span>
+<span class="k">store</span> <span class="k">i32</span> <span class="m">3</span><span class="p">,</span> <span class="k">i32</span><span class="p">*</span> <span class="nv">%ptr</span>                          <span class="c">; yields void</span>
+<span class="nv">%val</span> <span class="p">=</span> <span class="k">load</span> <span class="k">i32</span><span class="p">*</span> <span class="nv">%ptr</span>                           <span class="c">; yields i32:val = i32 3</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="fence-instruction">
+<span id="i-fence"></span><h4><a class="toc-backref" href="#id872">‘<tt class="docutils literal"><span class="pre">fence</span></tt>‘ Instruction</a><a class="headerlink" href="#fence-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id164">
+<h5><a class="toc-backref" href="#id873">Syntax:</a><a class="headerlink" href="#id164" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>fence [singlethread] <ordering>                   ; yields void
+</pre></div>
+</div>
+</div>
+<div class="section" id="id165">
+<h5><a class="toc-backref" href="#id874">Overview:</a><a class="headerlink" href="#id165" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fence</span></tt>‘ instruction is used to introduce happens-before edges
+between operations.</p>
+</div>
+<div class="section" id="id166">
+<h5><a class="toc-backref" href="#id875">Arguments:</a><a class="headerlink" href="#id166" title="Permalink to this headline">¶</a></h5>
+<p>‘<tt class="docutils literal"><span class="pre">fence</span></tt>‘ instructions take an <a class="reference internal" href="#ordering"><em>ordering</em></a> argument which
+defines what <em>synchronizes-with</em> edges they add. They can only be given
+<tt class="docutils literal"><span class="pre">acquire</span></tt>, <tt class="docutils literal"><span class="pre">release</span></tt>, <tt class="docutils literal"><span class="pre">acq_rel</span></tt>, and <tt class="docutils literal"><span class="pre">seq_cst</span></tt> orderings.</p>
+</div>
+<div class="section" id="id167">
+<h5><a class="toc-backref" href="#id876">Semantics:</a><a class="headerlink" href="#id167" title="Permalink to this headline">¶</a></h5>
+<p>A fence A which has (at least) <tt class="docutils literal"><span class="pre">release</span></tt> ordering semantics
+<em>synchronizes with</em> a fence B with (at least) <tt class="docutils literal"><span class="pre">acquire</span></tt> ordering
+semantics if and only if there exist atomic operations X and Y, both
+operating on some atomic object M, such that A is sequenced before X, X
+modifies M (either directly or through some side effect of a sequence
+headed by X), Y is sequenced before B, and Y observes M. This provides a
+<em>happens-before</em> dependency between A and B. Rather than an explicit
+<tt class="docutils literal"><span class="pre">fence</span></tt>, one (but not both) of the atomic operations X or Y might
+provide a <tt class="docutils literal"><span class="pre">release</span></tt> or <tt class="docutils literal"><span class="pre">acquire</span></tt> (resp.) ordering constraint and
+still <em>synchronize-with</em> the explicit <tt class="docutils literal"><span class="pre">fence</span></tt> and establish the
+<em>happens-before</em> edge.</p>
+<p>A <tt class="docutils literal"><span class="pre">fence</span></tt> which has <tt class="docutils literal"><span class="pre">seq_cst</span></tt> ordering, in addition to having both
+<tt class="docutils literal"><span class="pre">acquire</span></tt> and <tt class="docutils literal"><span class="pre">release</span></tt> semantics specified above, participates in
+the global program order of other <tt class="docutils literal"><span class="pre">seq_cst</span></tt> operations and/or fences.</p>
+<p>The optional “<a class="reference internal" href="#singlethread"><em>singlethread</em></a>” argument specifies
+that the fence only synchronizes with other fences in the same thread.
+(This is useful for interacting with signal handlers.)</p>
+</div>
+<div class="section" id="id168">
+<h5><a class="toc-backref" href="#id877">Example:</a><a class="headerlink" href="#id168" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre>fence acquire                          ; yields void
+fence singlethread seq_cst             ; yields void
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="cmpxchg-instruction">
+<span id="i-cmpxchg"></span><h4><a class="toc-backref" href="#id878">‘<tt class="docutils literal"><span class="pre">cmpxchg</span></tt>‘ Instruction</a><a class="headerlink" href="#cmpxchg-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id169">
+<h5><a class="toc-backref" href="#id879">Syntax:</a><a class="headerlink" href="#id169" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>cmpxchg [weak] [volatile] <ty>* <pointer>, <ty> <cmp>, <ty> <new> [singlethread] <success ordering> <failure ordering> ; yields  { ty, i1 }
+</pre></div>
+</div>
+</div>
+<div class="section" id="id170">
+<h5><a class="toc-backref" href="#id880">Overview:</a><a class="headerlink" href="#id170" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">cmpxchg</span></tt>‘ instruction is used to atomically modify memory. It
+loads a value in memory and compares it to a given value. If they are
+equal, it tries to store a new value into the memory.</p>
+</div>
+<div class="section" id="id171">
+<h5><a class="toc-backref" href="#id881">Arguments:</a><a class="headerlink" href="#id171" title="Permalink to this headline">¶</a></h5>
+<p>There are three arguments to the ‘<tt class="docutils literal"><span class="pre">cmpxchg</span></tt>‘ instruction: an address
+to operate on, a value to compare to the value currently be at that
+address, and a new value to place at that address if the compared values
+are equal. The type of ‘<cmp>’ must be an integer type whose bit width
+is a power of two greater than or equal to eight and less than or equal
+to a target-specific size limit. ‘<cmp>’ and ‘<new>’ must have the same
+type, and the type of ‘<pointer>’ must be a pointer to that type. If the
+<tt class="docutils literal"><span class="pre">cmpxchg</span></tt> is marked as <tt class="docutils literal"><span class="pre">volatile</span></tt>, then the optimizer is not allowed
+to modify the number or order of execution of this <tt class="docutils literal"><span class="pre">cmpxchg</span></tt> with
+other <a class="reference internal" href="#volatile"><em>volatile operations</em></a>.</p>
+<p>The success and failure <a class="reference internal" href="#ordering"><em>ordering</em></a> arguments specify how this
+<tt class="docutils literal"><span class="pre">cmpxchg</span></tt> synchronizes with other atomic operations. Both ordering parameters
+must be at least <tt class="docutils literal"><span class="pre">monotonic</span></tt>, the ordering constraint on failure must be no
+stronger than that on success, and the failure ordering cannot be either
+<tt class="docutils literal"><span class="pre">release</span></tt> or <tt class="docutils literal"><span class="pre">acq_rel</span></tt>.</p>
+<p>The optional “<tt class="docutils literal"><span class="pre">singlethread</span></tt>” argument declares that the <tt class="docutils literal"><span class="pre">cmpxchg</span></tt>
+is only atomic with respect to code (usually signal handlers) running in
+the same thread as the <tt class="docutils literal"><span class="pre">cmpxchg</span></tt>. Otherwise the cmpxchg is atomic with
+respect to all other code in the system.</p>
+<p>The pointer passed into cmpxchg must have alignment greater than or
+equal to the size in memory of the operand.</p>
+</div>
+<div class="section" id="id172">
+<h5><a class="toc-backref" href="#id882">Semantics:</a><a class="headerlink" href="#id172" title="Permalink to this headline">¶</a></h5>
+<p>The contents of memory at the location specified by the ‘<tt class="docutils literal"><span class="pre"><pointer></span></tt>‘ operand
+is read and compared to ‘<tt class="docutils literal"><span class="pre"><cmp></span></tt>‘; if the read value is the equal, the
+‘<tt class="docutils literal"><span class="pre"><new></span></tt>‘ is written. The original value at the location is returned, together
+with a flag indicating success (true) or failure (false).</p>
+<p>If the cmpxchg operation is marked as <tt class="docutils literal"><span class="pre">weak</span></tt> then a spurious failure is
+permitted: the operation may not write <tt class="docutils literal"><span class="pre"><new></span></tt> even if the comparison
+matched.</p>
+<p>If the cmpxchg operation is strong (the default), the i1 value is 1 if and only
+if the value loaded equals <tt class="docutils literal"><span class="pre">cmp</span></tt>.</p>
+<p>A successful <tt class="docutils literal"><span class="pre">cmpxchg</span></tt> is a read-modify-write instruction for the purpose of
+identifying release sequences. A failed <tt class="docutils literal"><span class="pre">cmpxchg</span></tt> is equivalent to an atomic
+load with an ordering parameter determined the second ordering parameter.</p>
+</div>
+<div class="section" id="id173">
+<h5><a class="toc-backref" href="#id883">Example:</a><a class="headerlink" href="#id173" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre>entry:
+  %orig = atomic load i32* %ptr unordered                   ; yields i32
+  br label %loop
+
+loop:
+  %cmp = phi i32 [ %orig, %entry ], [%old, %loop]
+  %squared = mul i32 %cmp, %cmp
+  %val_success = cmpxchg i32* %ptr, i32 %cmp, i32 %squared acq_rel monotonic ; yields  { i32, i1 }
+  %value_loaded = extractvalue { i32, i1 } %val_success, 0
+  %success = extractvalue { i32, i1 } %val_success, 1
+  br i1 %success, label %done, label %loop
+
+done:
+  ...
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="atomicrmw-instruction">
+<span id="i-atomicrmw"></span><h4><a class="toc-backref" href="#id884">‘<tt class="docutils literal"><span class="pre">atomicrmw</span></tt>‘ Instruction</a><a class="headerlink" href="#atomicrmw-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id174">
+<h5><a class="toc-backref" href="#id885">Syntax:</a><a class="headerlink" href="#id174" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>atomicrmw [volatile] <operation> <ty>* <pointer>, <ty> <value> [singlethread] <ordering>                   ; yields ty
+</pre></div>
+</div>
+</div>
+<div class="section" id="id175">
+<h5><a class="toc-backref" href="#id886">Overview:</a><a class="headerlink" href="#id175" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">atomicrmw</span></tt>‘ instruction is used to atomically modify memory.</p>
+</div>
+<div class="section" id="id176">
+<h5><a class="toc-backref" href="#id887">Arguments:</a><a class="headerlink" href="#id176" title="Permalink to this headline">¶</a></h5>
+<p>There are three arguments to the ‘<tt class="docutils literal"><span class="pre">atomicrmw</span></tt>‘ instruction: an
+operation to apply, an address whose value to modify, an argument to the
+operation. The operation must be one of the following keywords:</p>
+<ul class="simple">
+<li>xchg</li>
+<li>add</li>
+<li>sub</li>
+<li>and</li>
+<li>nand</li>
+<li>or</li>
+<li>xor</li>
+<li>max</li>
+<li>min</li>
+<li>umax</li>
+<li>umin</li>
+</ul>
+<p>The type of ‘<value>’ must be an integer type whose bit width is a power
+of two greater than or equal to eight and less than or equal to a
+target-specific size limit. The type of the ‘<tt class="docutils literal"><span class="pre"><pointer></span></tt>‘ operand must
+be a pointer to that type. If the <tt class="docutils literal"><span class="pre">atomicrmw</span></tt> is marked as
+<tt class="docutils literal"><span class="pre">volatile</span></tt>, then the optimizer is not allowed to modify the number or
+order of execution of this <tt class="docutils literal"><span class="pre">atomicrmw</span></tt> with other <a class="reference internal" href="#volatile"><em>volatile
+operations</em></a>.</p>
+</div>
+<div class="section" id="id177">
+<h5><a class="toc-backref" href="#id888">Semantics:</a><a class="headerlink" href="#id177" title="Permalink to this headline">¶</a></h5>
+<p>The contents of memory at the location specified by the ‘<tt class="docutils literal"><span class="pre"><pointer></span></tt>‘
+operand are atomically read, modified, and written back. The original
+value at the location is returned. The modification is specified by the
+operation argument:</p>
+<ul class="simple">
+<li>xchg: <tt class="docutils literal"><span class="pre">*ptr</span> <span class="pre">=</span> <span class="pre">val</span></tt></li>
+<li>add: <tt class="docutils literal"><span class="pre">*ptr</span> <span class="pre">=</span> <span class="pre">*ptr</span> <span class="pre">+</span> <span class="pre">val</span></tt></li>
+<li>sub: <tt class="docutils literal"><span class="pre">*ptr</span> <span class="pre">=</span> <span class="pre">*ptr</span> <span class="pre">-</span> <span class="pre">val</span></tt></li>
+<li>and: <tt class="docutils literal"><span class="pre">*ptr</span> <span class="pre">=</span> <span class="pre">*ptr</span> <span class="pre">&</span> <span class="pre">val</span></tt></li>
+<li>nand: <tt class="docutils literal"><span class="pre">*ptr</span> <span class="pre">=</span> <span class="pre">~(*ptr</span> <span class="pre">&</span> <span class="pre">val)</span></tt></li>
+<li>or: <tt class="docutils literal"><span class="pre">*ptr</span> <span class="pre">=</span> <span class="pre">*ptr</span> <span class="pre">|</span> <span class="pre">val</span></tt></li>
+<li>xor: <tt class="docutils literal"><span class="pre">*ptr</span> <span class="pre">=</span> <span class="pre">*ptr</span> <span class="pre">^</span> <span class="pre">val</span></tt></li>
+<li>max: <tt class="docutils literal"><span class="pre">*ptr</span> <span class="pre">=</span> <span class="pre">*ptr</span> <span class="pre">></span> <span class="pre">val</span> <span class="pre">?</span> <span class="pre">*ptr</span> <span class="pre">:</span> <span class="pre">val</span></tt> (using a signed comparison)</li>
+<li>min: <tt class="docutils literal"><span class="pre">*ptr</span> <span class="pre">=</span> <span class="pre">*ptr</span> <span class="pre"><</span> <span class="pre">val</span> <span class="pre">?</span> <span class="pre">*ptr</span> <span class="pre">:</span> <span class="pre">val</span></tt> (using a signed comparison)</li>
+<li>umax: <tt class="docutils literal"><span class="pre">*ptr</span> <span class="pre">=</span> <span class="pre">*ptr</span> <span class="pre">></span> <span class="pre">val</span> <span class="pre">?</span> <span class="pre">*ptr</span> <span class="pre">:</span> <span class="pre">val</span></tt> (using an unsigned
+comparison)</li>
+<li>umin: <tt class="docutils literal"><span class="pre">*ptr</span> <span class="pre">=</span> <span class="pre">*ptr</span> <span class="pre"><</span> <span class="pre">val</span> <span class="pre">?</span> <span class="pre">*ptr</span> <span class="pre">:</span> <span class="pre">val</span></tt> (using an unsigned
+comparison)</li>
+</ul>
+</div>
+<div class="section" id="id178">
+<h5><a class="toc-backref" href="#id889">Example:</a><a class="headerlink" href="#id178" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre>%old = atomicrmw add i32* %ptr, i32 1 acquire                        ; yields i32
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="getelementptr-instruction">
+<span id="i-getelementptr"></span><h4><a class="toc-backref" href="#id890">‘<tt class="docutils literal"><span class="pre">getelementptr</span></tt>‘ Instruction</a><a class="headerlink" href="#getelementptr-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id179">
+<h5><a class="toc-backref" href="#id891">Syntax:</a><a class="headerlink" href="#id179" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
+<result> = getelementptr inbounds <pty>* <ptrval>{, <ty> <idx>}*
+<result> = getelementptr <ptr vector> ptrval, <vector index type> idx
+</pre></div>
+</div>
+</div>
+<div class="section" id="id180">
+<h5><a class="toc-backref" href="#id892">Overview:</a><a class="headerlink" href="#id180" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">getelementptr</span></tt>‘ instruction is used to get the address of a
+subelement of an <a class="reference internal" href="#t-aggregate"><em>aggregate</em></a> data structure. It performs
+address calculation only and does not access memory.</p>
+</div>
+<div class="section" id="id181">
+<h5><a class="toc-backref" href="#id893">Arguments:</a><a class="headerlink" href="#id181" title="Permalink to this headline">¶</a></h5>
+<p>The first argument is always a pointer or a vector of pointers, and
+forms the basis of the calculation. The remaining arguments are indices
+that indicate which of the elements of the aggregate object are indexed.
+The interpretation of each index is dependent on the type being indexed
+into. The first index always indexes the pointer value given as the
+first argument, the second index indexes a value of the type pointed to
+(not necessarily the value directly pointed to, since the first index
+can be non-zero), etc. The first type indexed into must be a pointer
+value, subsequent types can be arrays, vectors, and structs. Note that
+subsequent types being indexed into can never be pointers, since that
+would require loading the pointer before continuing calculation.</p>
+<p>The type of each index argument depends on the type it is indexing into.
+When indexing into a (optionally packed) structure, only <tt class="docutils literal"><span class="pre">i32</span></tt> integer
+<strong>constants</strong> are allowed (when using a vector of indices they must all
+be the <strong>same</strong> <tt class="docutils literal"><span class="pre">i32</span></tt> integer constant). When indexing into an array,
+pointer or vector, integers of any width are allowed, and they are not
+required to be constant. These integers are treated as signed values
+where relevant.</p>
+<p>For example, let’s consider a C code fragment and how it gets compiled
+to LLVM:</p>
+<div class="highlight-c"><div class="highlight"><pre><span class="k">struct</span> <span class="n">RT</span> <span class="p">{</span>
+  <span class="kt">char</span> <span class="n">A</span><span class="p">;</span>
+  <span class="kt">int</span> <span class="n">B</span><span class="p">[</span><span class="mi">10</span><span class="p">][</span><span class="mi">20</span><span class="p">];</span>
+  <span class="kt">char</span> <span class="n">C</span><span class="p">;</span>
+<span class="p">};</span>
+<span class="k">struct</span> <span class="n">ST</span> <span class="p">{</span>
+  <span class="kt">int</span> <span class="n">X</span><span class="p">;</span>
+  <span class="kt">double</span> <span class="n">Y</span><span class="p">;</span>
+  <span class="k">struct</span> <span class="n">RT</span> <span class="n">Z</span><span class="p">;</span>
+<span class="p">};</span>
+
+<span class="kt">int</span> <span class="o">*</span><span class="nf">foo</span><span class="p">(</span><span class="k">struct</span> <span class="n">ST</span> <span class="o">*</span><span class="n">s</span><span class="p">)</span> <span class="p">{</span>
+  <span class="k">return</span> <span class="o">&</span><span class="n">s</span><span class="p">[</span><span class="mi">1</span><span class="p">].</span><span class="n">Z</span><span class="p">.</span><span class="n">B</span><span class="p">[</span><span class="mi">5</span><span class="p">][</span><span class="mi">13</span><span class="p">];</span>
+<span class="p">}</span>
+</pre></div>
+</div>
+<p>The LLVM code generated by Clang is:</p>
+<div class="highlight-llvm"><div class="highlight"><pre>%struct.RT = type { i8, [10 x [20 x i32]], i8 }
+%struct.ST = type { i32, double, %struct.RT }
+
+define i32* @foo(%struct.ST* %s) nounwind uwtable readnone optsize ssp {
+entry:
+  %arrayidx = getelementptr inbounds %struct.ST* %s, i64 1, i32 2, i32 1, i64 5, i64 13
+  ret i32* %arrayidx
+}
+</pre></div>
+</div>
+</div>
+<div class="section" id="id182">
+<h5><a class="toc-backref" href="#id894">Semantics:</a><a class="headerlink" href="#id182" title="Permalink to this headline">¶</a></h5>
+<p>In the example above, the first index is indexing into the
+‘<tt class="docutils literal"><span class="pre">%struct.ST*</span></tt>‘ type, which is a pointer, yielding a ‘<tt class="docutils literal"><span class="pre">%struct.ST</span></tt>‘
+= ‘<tt class="docutils literal"><span class="pre">{</span> <span class="pre">i32,</span> <span class="pre">double,</span> <span class="pre">%struct.RT</span> <span class="pre">}</span></tt>‘ type, a structure. The second index
+indexes into the third element of the structure, yielding a
+‘<tt class="docutils literal"><span class="pre">%struct.RT</span></tt>‘ = ‘<tt class="docutils literal"><span class="pre">{</span> <span class="pre">i8</span> <span class="pre">,</span> <span class="pre">[10</span> <span class="pre">x</span> <span class="pre">[20</span> <span class="pre">x</span> <span class="pre">i32]],</span> <span class="pre">i8</span> <span class="pre">}</span></tt>‘ type, another
+structure. The third index indexes into the second element of the
+structure, yielding a ‘<tt class="docutils literal"><span class="pre">[10</span> <span class="pre">x</span> <span class="pre">[20</span> <span class="pre">x</span> <span class="pre">i32]]</span></tt>‘ type, an array. The two
+dimensions of the array are subscripted into, yielding an ‘<tt class="docutils literal"><span class="pre">i32</span></tt>‘
+type. The ‘<tt class="docutils literal"><span class="pre">getelementptr</span></tt>‘ instruction returns a pointer to this
+element, thus computing a value of ‘<tt class="docutils literal"><span class="pre">i32*</span></tt>‘ type.</p>
+<p>Note that it is perfectly legal to index partially through a structure,
+returning a pointer to an inner element. Because of this, the LLVM code
+for the given testcase is equivalent to:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="k">define</span> <span class="k">i32</span><span class="p">*</span> <span class="vg">@foo</span><span class="p">(</span><span class="nv">%struct.ST</span><span class="p">*</span> <span class="nv">%s</span><span class="p">)</span> <span class="p">{</span>
+  <span class="nv">%t1</span> <span class="p">=</span> <span class="k">getelementptr</span> <span class="nv">%struct.ST</span><span class="p">*</span> <span class="nv">%s</span><span class="p">,</span> <span class="k">i32</span> <span class="m">1</span>                 <span class="c">; yields %struct.ST*:%t1</span>
+  <span class="nv">%t2</span> <span class="p">=</span> <span class="k">getelementptr</span> <span class="nv">%struct.ST</span><span class="p">*</span> <span class="nv">%t1</span><span class="p">,</span> <span class="k">i32</span> <span class="m">0</span><span class="p">,</span> <span class="k">i32</span> <span class="m">2</span>         <span class="c">; yields %struct.RT*:%t2</span>
+  <span class="nv">%t3</span> <span class="p">=</span> <span class="k">getelementptr</span> <span class="nv">%struct.RT</span><span class="p">*</span> <span class="nv">%t2</span><span class="p">,</span> <span class="k">i32</span> <span class="m">0</span><span class="p">,</span> <span class="k">i32</span> <span class="m">1</span>         <span class="c">; yields [10 x [20 x i32]]*:%t3</span>
+  <span class="nv">%t4</span> <span class="p">=</span> <span class="k">getelementptr</span> <span class="p">[</span><span class="m">10</span> <span class="k">x</span> <span class="p">[</span><span class="m">20</span> <span class="k">x</span> <span class="k">i32</span><span class="p">]]*</span> <span class="nv">%t3</span><span class="p">,</span> <span class="k">i32</span> <span class="m">0</span><span class="p">,</span> <span class="k">i32</span> <span class="m">5</span>  <span class="c">; yields [20 x i32]*:%t4</span>
+  <span class="nv">%t5</span> <span class="p">=</span> <span class="k">getelementptr</span> <span class="p">[</span><span class="m">20</span> <span class="k">x</span> <span class="k">i32</span><span class="p">]*</span> <span class="nv">%t4</span><span class="p">,</span> <span class="k">i32</span> <span class="m">0</span><span class="p">,</span> <span class="k">i32</span> <span class="m">13</span>        <span class="c">; yields i32*:%t5</span>
+  <span class="k">ret</span> <span class="k">i32</span><span class="p">*</span> <span class="nv">%t5</span>
+<span class="p">}</span>
+</pre></div>
+</div>
+<p>If the <tt class="docutils literal"><span class="pre">inbounds</span></tt> keyword is present, the result value of the
+<tt class="docutils literal"><span class="pre">getelementptr</span></tt> is a <a class="reference internal" href="#poisonvalues"><em>poison value</em></a> if the base
+pointer is not an <em>in bounds</em> address of an allocated object, or if any
+of the addresses that would be formed by successive addition of the
+offsets implied by the indices to the base address with infinitely
+precise signed arithmetic are not an <em>in bounds</em> address of that
+allocated object. The <em>in bounds</em> addresses for an allocated object are
+all the addresses that point into the object, plus the address one byte
+past the end. In cases where the base is a vector of pointers the
+<tt class="docutils literal"><span class="pre">inbounds</span></tt> keyword applies to each of the computations element-wise.</p>
+<p>If the <tt class="docutils literal"><span class="pre">inbounds</span></tt> keyword is not present, the offsets are added to the
+base address with silently-wrapping two’s complement arithmetic. If the
+offsets have a different width from the pointer, they are sign-extended
+or truncated to the width of the pointer. The result value of the
+<tt class="docutils literal"><span class="pre">getelementptr</span></tt> may be outside the object pointed to by the base
+pointer. The result value may not necessarily be used to access memory
+though, even if it happens to point into allocated storage. See the
+<a class="reference internal" href="#pointeraliasing"><em>Pointer Aliasing Rules</em></a> section for more
+information.</p>
+<p>The getelementptr instruction is often confusing. For some more insight
+into how it works, see <a class="reference internal" href="GetElementPtr.html"><em>the getelementptr FAQ</em></a>.</p>
+</div>
+<div class="section" id="id183">
+<h5><a class="toc-backref" href="#id895">Example:</a><a class="headerlink" href="#id183" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="c">; yields [12 x i8]*:aptr</span>
+<span class="nv">%aptr</span> <span class="p">=</span> <span class="k">getelementptr</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="p">[</span><span class="m">12</span> <span class="k">x</span> <span class="k">i8</span><span class="p">]}*</span> <span class="nv">%saptr</span><span class="p">,</span> <span class="k">i64</span> <span class="m">0</span><span class="p">,</span> <span class="k">i32</span> <span class="m">1</span>
+<span class="c">; yields i8*:vptr</span>
+<span class="nv">%vptr</span> <span class="p">=</span> <span class="k">getelementptr</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="p"><</span><span class="m">2</span> <span class="k">x</span> <span class="k">i8</span><span class="p">>}*</span> <span class="nv">%svptr</span><span class="p">,</span> <span class="k">i64</span> <span class="m">0</span><span class="p">,</span> <span class="k">i32</span> <span class="m">1</span><span class="p">,</span> <span class="k">i32</span> <span class="m">1</span>
+<span class="c">; yields i8*:eptr</span>
+<span class="nv">%eptr</span> <span class="p">=</span> <span class="k">getelementptr</span> <span class="p">[</span><span class="m">12</span> <span class="k">x</span> <span class="k">i8</span><span class="p">]*</span> <span class="nv">%aptr</span><span class="p">,</span> <span class="k">i64</span> <span class="m">0</span><span class="p">,</span> <span class="k">i32</span> <span class="m">1</span>
+<span class="c">; yields i32*:iptr</span>
+<span class="nv">%iptr</span> <span class="p">=</span> <span class="k">getelementptr</span> <span class="p">[</span><span class="m">10</span> <span class="k">x</span> <span class="k">i32</span><span class="p">]*</span> <span class="vg">@arr</span><span class="p">,</span> <span class="k">i16</span> <span class="m">0</span><span class="p">,</span> <span class="k">i16</span> <span class="m">0</span>
+</pre></div>
+</div>
+<p>In cases where the pointer argument is a vector of pointers, each index
+must be a vector with the same number of elements. For example:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%A</span> <span class="p">=</span> <span class="k">getelementptr</span> <span class="p"><</span><span class="m">4</span> <span class="k">x</span> <span class="k">i8</span><span class="p">*></span> <span class="nv">%ptrs</span><span class="p">,</span> <span class="p"><</span><span class="m">4</span> <span class="k">x</span> <span class="k">i64</span><span class="p">></span> <span class="nv">%offsets</span><span class="p">,</span>
+</pre></div>
+</div>
+</div>
+</div>
+</div>
+<div class="section" id="conversion-operations">
+<h3><a class="toc-backref" href="#id896">Conversion Operations</a><a class="headerlink" href="#conversion-operations" title="Permalink to this headline">¶</a></h3>
+<p>The instructions in this category are the conversion instructions
+(casting) which all take a single operand and a type. They perform
+various bit conversions on the operand.</p>
+<div class="section" id="trunc-to-instruction">
+<h4><a class="toc-backref" href="#id897">‘<tt class="docutils literal"><span class="pre">trunc</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><a class="headerlink" href="#trunc-to-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id184">
+<h5><a class="toc-backref" href="#id898">Syntax:</a><a class="headerlink" href="#id184" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = trunc <ty> <value> to <ty2>             ; yields ty2
+</pre></div>
+</div>
+</div>
+<div class="section" id="id185">
+<h5><a class="toc-backref" href="#id899">Overview:</a><a class="headerlink" href="#id185" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">trunc</span></tt>‘ instruction truncates its operand to the type <tt class="docutils literal"><span class="pre">ty2</span></tt>.</p>
+</div>
+<div class="section" id="id186">
+<h5><a class="toc-backref" href="#id900">Arguments:</a><a class="headerlink" href="#id186" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">trunc</span></tt>‘ instruction takes a value to trunc, and a type to trunc
+it to. Both types must be of <a class="reference internal" href="#t-integer"><em>integer</em></a> types, or vectors
+of the same number of integers. The bit size of the <tt class="docutils literal"><span class="pre">value</span></tt> must be
+larger than the bit size of the destination type, <tt class="docutils literal"><span class="pre">ty2</span></tt>. Equal sized
+types are not allowed.</p>
+</div>
+<div class="section" id="id187">
+<h5><a class="toc-backref" href="#id901">Semantics:</a><a class="headerlink" href="#id187" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">trunc</span></tt>‘ instruction truncates the high order bits in <tt class="docutils literal"><span class="pre">value</span></tt>
+and converts the remaining bits to <tt class="docutils literal"><span class="pre">ty2</span></tt>. Since the source size must
+be larger than the destination size, <tt class="docutils literal"><span class="pre">trunc</span></tt> cannot be a <em>no-op cast</em>.
+It will always truncate bits.</p>
+</div>
+<div class="section" id="id188">
+<h5><a class="toc-backref" href="#id902">Example:</a><a class="headerlink" href="#id188" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%X</span> <span class="p">=</span> <span class="k">trunc</span> <span class="k">i32</span> <span class="m">257</span> <span class="k">to</span> <span class="k">i8</span>                        <span class="c">; yields i8:1</span>
+<span class="nv">%Y</span> <span class="p">=</span> <span class="k">trunc</span> <span class="k">i32</span> <span class="m">123</span> <span class="k">to</span> <span class="k">i1</span>                        <span class="c">; yields i1:true</span>
+<span class="nv">%Z</span> <span class="p">=</span> <span class="k">trunc</span> <span class="k">i32</span> <span class="m">122</span> <span class="k">to</span> <span class="k">i1</span>                        <span class="c">; yields i1:false</span>
+<span class="nv">%W</span> <span class="p">=</span> <span class="k">trunc</span> <span class="p"><</span><span class="m">2</span> <span class="k">x</span> <span class="k">i16</span><span class="p">></span> <span class="p"><</span><span class="k">i16</span> <span class="m">8</span><span class="p">,</span> <span class="k">i16</span> <span class="m">7</span><span class="p">></span> <span class="k">to</span> <span class="p"><</span><span class="m">2</span> <span class="k">x</span> <span class="k">i8</span><span class="p">></span> <span class="c">; yields <i8 8, i8 7></span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="zext-to-instruction">
+<h4><a class="toc-backref" href="#id903">‘<tt class="docutils literal"><span class="pre">zext</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><a class="headerlink" href="#zext-to-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id189">
+<h5><a class="toc-backref" href="#id904">Syntax:</a><a class="headerlink" href="#id189" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = zext <ty> <value> to <ty2>             ; yields ty2
+</pre></div>
+</div>
+</div>
+<div class="section" id="id190">
+<h5><a class="toc-backref" href="#id905">Overview:</a><a class="headerlink" href="#id190" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">zext</span></tt>‘ instruction zero extends its operand to type <tt class="docutils literal"><span class="pre">ty2</span></tt>.</p>
+</div>
+<div class="section" id="id191">
+<h5><a class="toc-backref" href="#id906">Arguments:</a><a class="headerlink" href="#id191" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">zext</span></tt>‘ instruction takes a value to cast, and a type to cast it
+to. Both types must be of <a class="reference internal" href="#t-integer"><em>integer</em></a> types, or vectors of
+the same number of integers. The bit size of the <tt class="docutils literal"><span class="pre">value</span></tt> must be
+smaller than the bit size of the destination type, <tt class="docutils literal"><span class="pre">ty2</span></tt>.</p>
+</div>
+<div class="section" id="id192">
+<h5><a class="toc-backref" href="#id907">Semantics:</a><a class="headerlink" href="#id192" title="Permalink to this headline">¶</a></h5>
+<p>The <tt class="docutils literal"><span class="pre">zext</span></tt> fills the high order bits of the <tt class="docutils literal"><span class="pre">value</span></tt> with zero bits
+until it reaches the size of the destination type, <tt class="docutils literal"><span class="pre">ty2</span></tt>.</p>
+<p>When zero extending from i1, the result will always be either 0 or 1.</p>
+</div>
+<div class="section" id="id193">
+<h5><a class="toc-backref" href="#id908">Example:</a><a class="headerlink" href="#id193" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%X</span> <span class="p">=</span> <span class="k">zext</span> <span class="k">i32</span> <span class="m">257</span> <span class="k">to</span> <span class="k">i64</span>              <span class="c">; yields i64:257</span>
+<span class="nv">%Y</span> <span class="p">=</span> <span class="k">zext</span> <span class="k">i1</span> <span class="k">true</span> <span class="k">to</span> <span class="k">i32</span>              <span class="c">; yields i32:1</span>
+<span class="nv">%Z</span> <span class="p">=</span> <span class="k">zext</span> <span class="p"><</span><span class="m">2</span> <span class="k">x</span> <span class="k">i16</span><span class="p">></span> <span class="p"><</span><span class="k">i16</span> <span class="m">8</span><span class="p">,</span> <span class="k">i16</span> <span class="m">7</span><span class="p">></span> <span class="k">to</span> <span class="p"><</span><span class="m">2</span> <span class="k">x</span> <span class="k">i32</span><span class="p">></span> <span class="c">; yields <i32 8, i32 7></span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="sext-to-instruction">
+<h4><a class="toc-backref" href="#id909">‘<tt class="docutils literal"><span class="pre">sext</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><a class="headerlink" href="#sext-to-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id194">
+<h5><a class="toc-backref" href="#id910">Syntax:</a><a class="headerlink" href="#id194" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = sext <ty> <value> to <ty2>             ; yields ty2
+</pre></div>
+</div>
+</div>
+<div class="section" id="id195">
+<h5><a class="toc-backref" href="#id911">Overview:</a><a class="headerlink" href="#id195" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">sext</span></tt>‘ sign extends <tt class="docutils literal"><span class="pre">value</span></tt> to the type <tt class="docutils literal"><span class="pre">ty2</span></tt>.</p>
+</div>
+<div class="section" id="id196">
+<h5><a class="toc-backref" href="#id912">Arguments:</a><a class="headerlink" href="#id196" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">sext</span></tt>‘ instruction takes a value to cast, and a type to cast it
+to. Both types must be of <a class="reference internal" href="#t-integer"><em>integer</em></a> types, or vectors of
+the same number of integers. The bit size of the <tt class="docutils literal"><span class="pre">value</span></tt> must be
+smaller than the bit size of the destination type, <tt class="docutils literal"><span class="pre">ty2</span></tt>.</p>
+</div>
+<div class="section" id="id197">
+<h5><a class="toc-backref" href="#id913">Semantics:</a><a class="headerlink" href="#id197" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">sext</span></tt>‘ instruction performs a sign extension by copying the sign
+bit (highest order bit) of the <tt class="docutils literal"><span class="pre">value</span></tt> until it reaches the bit size
+of the type <tt class="docutils literal"><span class="pre">ty2</span></tt>.</p>
+<p>When sign extending from i1, the extension always results in -1 or 0.</p>
+</div>
+<div class="section" id="id198">
+<h5><a class="toc-backref" href="#id914">Example:</a><a class="headerlink" href="#id198" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%X</span> <span class="p">=</span> <span class="k">sext</span> <span class="k">i8</span>  <span class="m">-1</span> <span class="k">to</span> <span class="k">i16</span>              <span class="c">; yields i16   :65535</span>
+<span class="nv">%Y</span> <span class="p">=</span> <span class="k">sext</span> <span class="k">i1</span> <span class="k">true</span> <span class="k">to</span> <span class="k">i32</span>             <span class="c">; yields i32:-1</span>
+<span class="nv">%Z</span> <span class="p">=</span> <span class="k">sext</span> <span class="p"><</span><span class="m">2</span> <span class="k">x</span> <span class="k">i16</span><span class="p">></span> <span class="p"><</span><span class="k">i16</span> <span class="m">8</span><span class="p">,</span> <span class="k">i16</span> <span class="m">7</span><span class="p">></span> <span class="k">to</span> <span class="p"><</span><span class="m">2</span> <span class="k">x</span> <span class="k">i32</span><span class="p">></span> <span class="c">; yields <i32 8, i32 7></span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="fptrunc-to-instruction">
+<h4><a class="toc-backref" href="#id915">‘<tt class="docutils literal"><span class="pre">fptrunc</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><a class="headerlink" href="#fptrunc-to-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id199">
+<h5><a class="toc-backref" href="#id916">Syntax:</a><a class="headerlink" href="#id199" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = fptrunc <ty> <value> to <ty2>             ; yields ty2
+</pre></div>
+</div>
+</div>
+<div class="section" id="id200">
+<h5><a class="toc-backref" href="#id917">Overview:</a><a class="headerlink" href="#id200" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fptrunc</span></tt>‘ instruction truncates <tt class="docutils literal"><span class="pre">value</span></tt> to type <tt class="docutils literal"><span class="pre">ty2</span></tt>.</p>
+</div>
+<div class="section" id="id201">
+<h5><a class="toc-backref" href="#id918">Arguments:</a><a class="headerlink" href="#id201" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fptrunc</span></tt>‘ instruction takes a <a class="reference internal" href="#t-floating"><em>floating point</em></a>
+value to cast and a <a class="reference internal" href="#t-floating"><em>floating point</em></a> type to cast it to.
+The size of <tt class="docutils literal"><span class="pre">value</span></tt> must be larger than the size of <tt class="docutils literal"><span class="pre">ty2</span></tt>. This
+implies that <tt class="docutils literal"><span class="pre">fptrunc</span></tt> cannot be used to make a <em>no-op cast</em>.</p>
+</div>
+<div class="section" id="id202">
+<h5><a class="toc-backref" href="#id919">Semantics:</a><a class="headerlink" href="#id202" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fptrunc</span></tt>‘ instruction truncates a <tt class="docutils literal"><span class="pre">value</span></tt> from a larger
+<a class="reference internal" href="#t-floating"><em>floating point</em></a> type to a smaller <a class="reference internal" href="#t-floating"><em>floating
+point</em></a> type. If the value cannot fit within the
+destination type, <tt class="docutils literal"><span class="pre">ty2</span></tt>, then the results are undefined.</p>
+</div>
+<div class="section" id="id203">
+<h5><a class="toc-backref" href="#id920">Example:</a><a class="headerlink" href="#id203" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%X</span> <span class="p">=</span> <span class="k">fptrunc</span> <span class="kt">double</span> <span class="m">123.0</span> <span class="k">to</span> <span class="kt">float</span>         <span class="c">; yields float:123.0</span>
+<span class="nv">%Y</span> <span class="p">=</span> <span class="k">fptrunc</span> <span class="kt">double</span> <span class="m">1.0E+300</span> <span class="k">to</span> <span class="kt">float</span>      <span class="c">; yields undefined</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="fpext-to-instruction">
+<h4><a class="toc-backref" href="#id921">‘<tt class="docutils literal"><span class="pre">fpext</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><a class="headerlink" href="#fpext-to-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id204">
+<h5><a class="toc-backref" href="#id922">Syntax:</a><a class="headerlink" href="#id204" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = fpext <ty> <value> to <ty2>             ; yields ty2
+</pre></div>
+</div>
+</div>
+<div class="section" id="id205">
+<h5><a class="toc-backref" href="#id923">Overview:</a><a class="headerlink" href="#id205" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fpext</span></tt>‘ extends a floating point <tt class="docutils literal"><span class="pre">value</span></tt> to a larger floating
+point value.</p>
+</div>
+<div class="section" id="id206">
+<h5><a class="toc-backref" href="#id924">Arguments:</a><a class="headerlink" href="#id206" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fpext</span></tt>‘ instruction takes a <a class="reference internal" href="#t-floating"><em>floating point</em></a>
+<tt class="docutils literal"><span class="pre">value</span></tt> to cast, and a <a class="reference internal" href="#t-floating"><em>floating point</em></a> type to cast it
+to. The source type must be smaller than the destination type.</p>
+</div>
+<div class="section" id="id207">
+<h5><a class="toc-backref" href="#id925">Semantics:</a><a class="headerlink" href="#id207" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fpext</span></tt>‘ instruction extends the <tt class="docutils literal"><span class="pre">value</span></tt> from a smaller
+<a class="reference internal" href="#t-floating"><em>floating point</em></a> type to a larger <a class="reference internal" href="#t-floating"><em>floating
+point</em></a> type. The <tt class="docutils literal"><span class="pre">fpext</span></tt> cannot be used to make a
+<em>no-op cast</em> because it always changes bits. Use <tt class="docutils literal"><span class="pre">bitcast</span></tt> to make a
+<em>no-op cast</em> for a floating point cast.</p>
+</div>
+<div class="section" id="id208">
+<h5><a class="toc-backref" href="#id926">Example:</a><a class="headerlink" href="#id208" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%X</span> <span class="p">=</span> <span class="k">fpext</span> <span class="kt">float</span> <span class="m">3.125</span> <span class="k">to</span> <span class="kt">double</span>         <span class="c">; yields double:3.125000e+00</span>
+<span class="nv">%Y</span> <span class="p">=</span> <span class="k">fpext</span> <span class="kt">double</span> <span class="nv">%X</span> <span class="k">to</span> <span class="kt">fp128</span>            <span class="c">; yields fp128:0xL00000000000000004000900000000000</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="fptoui-to-instruction">
+<h4><a class="toc-backref" href="#id927">‘<tt class="docutils literal"><span class="pre">fptoui</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><a class="headerlink" href="#fptoui-to-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id209">
+<h5><a class="toc-backref" href="#id928">Syntax:</a><a class="headerlink" href="#id209" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = fptoui <ty> <value> to <ty2>             ; yields ty2
+</pre></div>
+</div>
+</div>
+<div class="section" id="id210">
+<h5><a class="toc-backref" href="#id929">Overview:</a><a class="headerlink" href="#id210" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fptoui</span></tt>‘ converts a floating point <tt class="docutils literal"><span class="pre">value</span></tt> to its unsigned
+integer equivalent of type <tt class="docutils literal"><span class="pre">ty2</span></tt>.</p>
+</div>
+<div class="section" id="id211">
+<h5><a class="toc-backref" href="#id930">Arguments:</a><a class="headerlink" href="#id211" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fptoui</span></tt>‘ instruction takes a value to cast, which must be a
+scalar or vector <a class="reference internal" href="#t-floating"><em>floating point</em></a> value, and a type to
+cast it to <tt class="docutils literal"><span class="pre">ty2</span></tt>, which must be an <a class="reference internal" href="#t-integer"><em>integer</em></a> type. If
+<tt class="docutils literal"><span class="pre">ty</span></tt> is a vector floating point type, <tt class="docutils literal"><span class="pre">ty2</span></tt> must be a vector integer
+type with the same number of elements as <tt class="docutils literal"><span class="pre">ty</span></tt></p>
+</div>
+<div class="section" id="id212">
+<h5><a class="toc-backref" href="#id931">Semantics:</a><a class="headerlink" href="#id212" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fptoui</span></tt>‘ instruction converts its <a class="reference internal" href="#t-floating"><em>floating
+point</em></a> operand into the nearest (rounding towards zero)
+unsigned integer value. If the value cannot fit in <tt class="docutils literal"><span class="pre">ty2</span></tt>, the results
+are undefined.</p>
+</div>
+<div class="section" id="id213">
+<h5><a class="toc-backref" href="#id932">Example:</a><a class="headerlink" href="#id213" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre>%X = fptoui double 123.0 to i32      ; yields i32:123
+%Y = fptoui float 1.0E+300 to i1     ; yields undefined:1
+%Z = fptoui float 1.04E+17 to i8     ; yields undefined:1
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="fptosi-to-instruction">
+<h4><a class="toc-backref" href="#id933">‘<tt class="docutils literal"><span class="pre">fptosi</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><a class="headerlink" href="#fptosi-to-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id214">
+<h5><a class="toc-backref" href="#id934">Syntax:</a><a class="headerlink" href="#id214" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = fptosi <ty> <value> to <ty2>             ; yields ty2
+</pre></div>
+</div>
+</div>
+<div class="section" id="id215">
+<h5><a class="toc-backref" href="#id935">Overview:</a><a class="headerlink" href="#id215" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fptosi</span></tt>‘ instruction converts <a class="reference internal" href="#t-floating"><em>floating point</em></a>
+<tt class="docutils literal"><span class="pre">value</span></tt> to type <tt class="docutils literal"><span class="pre">ty2</span></tt>.</p>
+</div>
+<div class="section" id="id216">
+<h5><a class="toc-backref" href="#id936">Arguments:</a><a class="headerlink" href="#id216" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fptosi</span></tt>‘ instruction takes a value to cast, which must be a
+scalar or vector <a class="reference internal" href="#t-floating"><em>floating point</em></a> value, and a type to
+cast it to <tt class="docutils literal"><span class="pre">ty2</span></tt>, which must be an <a class="reference internal" href="#t-integer"><em>integer</em></a> type. If
+<tt class="docutils literal"><span class="pre">ty</span></tt> is a vector floating point type, <tt class="docutils literal"><span class="pre">ty2</span></tt> must be a vector integer
+type with the same number of elements as <tt class="docutils literal"><span class="pre">ty</span></tt></p>
+</div>
+<div class="section" id="id217">
+<h5><a class="toc-backref" href="#id937">Semantics:</a><a class="headerlink" href="#id217" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fptosi</span></tt>‘ instruction converts its <a class="reference internal" href="#t-floating"><em>floating
+point</em></a> operand into the nearest (rounding towards zero)
+signed integer value. If the value cannot fit in <tt class="docutils literal"><span class="pre">ty2</span></tt>, the results
+are undefined.</p>
+</div>
+<div class="section" id="id218">
+<h5><a class="toc-backref" href="#id938">Example:</a><a class="headerlink" href="#id218" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre>%X = fptosi double -123.0 to i32      ; yields i32:-123
+%Y = fptosi float 1.0E-247 to i1      ; yields undefined:1
+%Z = fptosi float 1.04E+17 to i8      ; yields undefined:1
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="uitofp-to-instruction">
+<h4><a class="toc-backref" href="#id939">‘<tt class="docutils literal"><span class="pre">uitofp</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><a class="headerlink" href="#uitofp-to-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id219">
+<h5><a class="toc-backref" href="#id940">Syntax:</a><a class="headerlink" href="#id219" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = uitofp <ty> <value> to <ty2>             ; yields ty2
+</pre></div>
+</div>
+</div>
+<div class="section" id="id220">
+<h5><a class="toc-backref" href="#id941">Overview:</a><a class="headerlink" href="#id220" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">uitofp</span></tt>‘ instruction regards <tt class="docutils literal"><span class="pre">value</span></tt> as an unsigned integer
+and converts that value to the <tt class="docutils literal"><span class="pre">ty2</span></tt> type.</p>
+</div>
+<div class="section" id="id221">
+<h5><a class="toc-backref" href="#id942">Arguments:</a><a class="headerlink" href="#id221" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">uitofp</span></tt>‘ instruction takes a value to cast, which must be a
+scalar or vector <a class="reference internal" href="#t-integer"><em>integer</em></a> value, and a type to cast it to
+<tt class="docutils literal"><span class="pre">ty2</span></tt>, which must be an <a class="reference internal" href="#t-floating"><em>floating point</em></a> type. If
+<tt class="docutils literal"><span class="pre">ty</span></tt> is a vector integer type, <tt class="docutils literal"><span class="pre">ty2</span></tt> must be a vector floating point
+type with the same number of elements as <tt class="docutils literal"><span class="pre">ty</span></tt></p>
+</div>
+<div class="section" id="id222">
+<h5><a class="toc-backref" href="#id943">Semantics:</a><a class="headerlink" href="#id222" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">uitofp</span></tt>‘ instruction interprets its operand as an unsigned
+integer quantity and converts it to the corresponding floating point
+value. If the value cannot fit in the floating point value, the results
+are undefined.</p>
+</div>
+<div class="section" id="id223">
+<h5><a class="toc-backref" href="#id944">Example:</a><a class="headerlink" href="#id223" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%X</span> <span class="p">=</span> <span class="k">uitofp</span> <span class="k">i32</span> <span class="m">257</span> <span class="k">to</span> <span class="kt">float</span>         <span class="c">; yields float:257.0</span>
+<span class="nv">%Y</span> <span class="p">=</span> <span class="k">uitofp</span> <span class="k">i8</span> <span class="m">-1</span> <span class="k">to</span> <span class="kt">double</span>          <span class="c">; yields double:255.0</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="sitofp-to-instruction">
+<h4><a class="toc-backref" href="#id945">‘<tt class="docutils literal"><span class="pre">sitofp</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><a class="headerlink" href="#sitofp-to-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id224">
+<h5><a class="toc-backref" href="#id946">Syntax:</a><a class="headerlink" href="#id224" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = sitofp <ty> <value> to <ty2>             ; yields ty2
+</pre></div>
+</div>
+</div>
+<div class="section" id="id225">
+<h5><a class="toc-backref" href="#id947">Overview:</a><a class="headerlink" href="#id225" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">sitofp</span></tt>‘ instruction regards <tt class="docutils literal"><span class="pre">value</span></tt> as a signed integer and
+converts that value to the <tt class="docutils literal"><span class="pre">ty2</span></tt> type.</p>
+</div>
+<div class="section" id="id226">
+<h5><a class="toc-backref" href="#id948">Arguments:</a><a class="headerlink" href="#id226" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">sitofp</span></tt>‘ instruction takes a value to cast, which must be a
+scalar or vector <a class="reference internal" href="#t-integer"><em>integer</em></a> value, and a type to cast it to
+<tt class="docutils literal"><span class="pre">ty2</span></tt>, which must be an <a class="reference internal" href="#t-floating"><em>floating point</em></a> type. If
+<tt class="docutils literal"><span class="pre">ty</span></tt> is a vector integer type, <tt class="docutils literal"><span class="pre">ty2</span></tt> must be a vector floating point
+type with the same number of elements as <tt class="docutils literal"><span class="pre">ty</span></tt></p>
+</div>
+<div class="section" id="id227">
+<h5><a class="toc-backref" href="#id949">Semantics:</a><a class="headerlink" href="#id227" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">sitofp</span></tt>‘ instruction interprets its operand as a signed integer
+quantity and converts it to the corresponding floating point value. If
+the value cannot fit in the floating point value, the results are
+undefined.</p>
+</div>
+<div class="section" id="id228">
+<h5><a class="toc-backref" href="#id950">Example:</a><a class="headerlink" href="#id228" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%X</span> <span class="p">=</span> <span class="k">sitofp</span> <span class="k">i32</span> <span class="m">257</span> <span class="k">to</span> <span class="kt">float</span>         <span class="c">; yields float:257.0</span>
+<span class="nv">%Y</span> <span class="p">=</span> <span class="k">sitofp</span> <span class="k">i8</span> <span class="m">-1</span> <span class="k">to</span> <span class="kt">double</span>          <span class="c">; yields double:-1.0</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="ptrtoint-to-instruction">
+<span id="i-ptrtoint"></span><h4><a class="toc-backref" href="#id951">‘<tt class="docutils literal"><span class="pre">ptrtoint</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><a class="headerlink" href="#ptrtoint-to-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id229">
+<h5><a class="toc-backref" href="#id952">Syntax:</a><a class="headerlink" href="#id229" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = ptrtoint <ty> <value> to <ty2>             ; yields ty2
+</pre></div>
+</div>
+</div>
+<div class="section" id="id230">
+<h5><a class="toc-backref" href="#id953">Overview:</a><a class="headerlink" href="#id230" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">ptrtoint</span></tt>‘ instruction converts the pointer or a vector of
+pointers <tt class="docutils literal"><span class="pre">value</span></tt> to the integer (or vector of integers) type <tt class="docutils literal"><span class="pre">ty2</span></tt>.</p>
+</div>
+<div class="section" id="id231">
+<h5><a class="toc-backref" href="#id954">Arguments:</a><a class="headerlink" href="#id231" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">ptrtoint</span></tt>‘ instruction takes a <tt class="docutils literal"><span class="pre">value</span></tt> to cast, which must be
+a a value of type <a class="reference internal" href="#t-pointer"><em>pointer</em></a> or a vector of pointers, and a
+type to cast it to <tt class="docutils literal"><span class="pre">ty2</span></tt>, which must be an <a class="reference internal" href="#t-integer"><em>integer</em></a> or
+a vector of integers type.</p>
+</div>
+<div class="section" id="id232">
+<h5><a class="toc-backref" href="#id955">Semantics:</a><a class="headerlink" href="#id232" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">ptrtoint</span></tt>‘ instruction converts <tt class="docutils literal"><span class="pre">value</span></tt> to integer type
+<tt class="docutils literal"><span class="pre">ty2</span></tt> by interpreting the pointer value as an integer and either
+truncating or zero extending that value to the size of the integer type.
+If <tt class="docutils literal"><span class="pre">value</span></tt> is smaller than <tt class="docutils literal"><span class="pre">ty2</span></tt> then a zero extension is done. If
+<tt class="docutils literal"><span class="pre">value</span></tt> is larger than <tt class="docutils literal"><span class="pre">ty2</span></tt> then a truncation is done. If they are
+the same size, then nothing is done (<em>no-op cast</em>) other than a type
+change.</p>
+</div>
+<div class="section" id="id233">
+<h5><a class="toc-backref" href="#id956">Example:</a><a class="headerlink" href="#id233" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%X</span> <span class="p">=</span> <span class="k">ptrtoint</span> <span class="k">i32</span><span class="p">*</span> <span class="nv">%P</span> <span class="k">to</span> <span class="k">i8</span>                         <span class="c">; yields truncation on 32-bit architecture</span>
+<span class="nv">%Y</span> <span class="p">=</span> <span class="k">ptrtoint</span> <span class="k">i32</span><span class="p">*</span> <span class="nv">%P</span> <span class="k">to</span> <span class="k">i64</span>                        <span class="c">; yields zero extension on 32-bit architecture</span>
+<span class="nv">%Z</span> <span class="p">=</span> <span class="k">ptrtoint</span> <span class="p"><</span><span class="m">4</span> <span class="k">x</span> <span class="k">i32</span><span class="p">*></span> <span class="nv">%P</span> <span class="k">to</span> <span class="p"><</span><span class="m">4</span> <span class="k">x</span> <span class="k">i64</span><span class="p">></span><span class="c">; yields vector zero extension for a vector of addresses on 32-bit architecture</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="inttoptr-to-instruction">
+<span id="i-inttoptr"></span><h4><a class="toc-backref" href="#id957">‘<tt class="docutils literal"><span class="pre">inttoptr</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><a class="headerlink" href="#inttoptr-to-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id234">
+<h5><a class="toc-backref" href="#id958">Syntax:</a><a class="headerlink" href="#id234" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = inttoptr <ty> <value> to <ty2>             ; yields ty2
+</pre></div>
+</div>
+</div>
+<div class="section" id="id235">
+<h5><a class="toc-backref" href="#id959">Overview:</a><a class="headerlink" href="#id235" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">inttoptr</span></tt>‘ instruction converts an integer <tt class="docutils literal"><span class="pre">value</span></tt> to a
+pointer type, <tt class="docutils literal"><span class="pre">ty2</span></tt>.</p>
+</div>
+<div class="section" id="id236">
+<h5><a class="toc-backref" href="#id960">Arguments:</a><a class="headerlink" href="#id236" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">inttoptr</span></tt>‘ instruction takes an <a class="reference internal" href="#t-integer"><em>integer</em></a> value to
+cast, and a type to cast it to, which must be a <a class="reference internal" href="#t-pointer"><em>pointer</em></a>
+type.</p>
+</div>
+<div class="section" id="id237">
+<h5><a class="toc-backref" href="#id961">Semantics:</a><a class="headerlink" href="#id237" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">inttoptr</span></tt>‘ instruction converts <tt class="docutils literal"><span class="pre">value</span></tt> to type <tt class="docutils literal"><span class="pre">ty2</span></tt> by
+applying either a zero extension or a truncation depending on the size
+of the integer <tt class="docutils literal"><span class="pre">value</span></tt>. If <tt class="docutils literal"><span class="pre">value</span></tt> is larger than the size of a
+pointer then a truncation is done. If <tt class="docutils literal"><span class="pre">value</span></tt> is smaller than the size
+of a pointer then a zero extension is done. If they are the same size,
+nothing is done (<em>no-op cast</em>).</p>
+</div>
+<div class="section" id="id238">
+<h5><a class="toc-backref" href="#id962">Example:</a><a class="headerlink" href="#id238" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%X</span> <span class="p">=</span> <span class="k">inttoptr</span> <span class="k">i32</span> <span class="m">255</span> <span class="k">to</span> <span class="k">i32</span><span class="p">*</span>          <span class="c">; yields zero extension on 64-bit architecture</span>
+<span class="nv">%Y</span> <span class="p">=</span> <span class="k">inttoptr</span> <span class="k">i32</span> <span class="m">255</span> <span class="k">to</span> <span class="k">i32</span><span class="p">*</span>          <span class="c">; yields no-op on 32-bit architecture</span>
+<span class="nv">%Z</span> <span class="p">=</span> <span class="k">inttoptr</span> <span class="k">i64</span> <span class="m">0</span> <span class="k">to</span> <span class="k">i32</span><span class="p">*</span>            <span class="c">; yields truncation on 32-bit architecture</span>
+<span class="nv">%Z</span> <span class="p">=</span> <span class="k">inttoptr</span> <span class="p"><</span><span class="m">4</span> <span class="k">x</span> <span class="k">i32</span><span class="p">></span> <span class="nv">%G</span> <span class="k">to</span> <span class="p"><</span><span class="m">4</span> <span class="k">x</span> <span class="k">i8</span><span class="p">*></span><span class="c">; yields truncation of vector G to four pointers</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="bitcast-to-instruction">
+<span id="i-bitcast"></span><h4><a class="toc-backref" href="#id963">‘<tt class="docutils literal"><span class="pre">bitcast</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><a class="headerlink" href="#bitcast-to-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id239">
+<h5><a class="toc-backref" href="#id964">Syntax:</a><a class="headerlink" href="#id239" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = bitcast <ty> <value> to <ty2>             ; yields ty2
+</pre></div>
+</div>
+</div>
+<div class="section" id="id240">
+<h5><a class="toc-backref" href="#id965">Overview:</a><a class="headerlink" href="#id240" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">bitcast</span></tt>‘ instruction converts <tt class="docutils literal"><span class="pre">value</span></tt> to type <tt class="docutils literal"><span class="pre">ty2</span></tt> without
+changing any bits.</p>
+</div>
+<div class="section" id="id241">
+<h5><a class="toc-backref" href="#id966">Arguments:</a><a class="headerlink" href="#id241" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">bitcast</span></tt>‘ instruction takes a value to cast, which must be a
+non-aggregate first class value, and a type to cast it to, which must
+also be a non-aggregate <a class="reference internal" href="#t-firstclass"><em>first class</em></a> type. The
+bit sizes of <tt class="docutils literal"><span class="pre">value</span></tt> and the destination type, <tt class="docutils literal"><span class="pre">ty2</span></tt>, must be
+identical.  If the source type is a pointer, the destination type must
+also be a pointer of the same size. This instruction supports bitwise
+conversion of vectors to integers and to vectors of other types (as
+long as they have the same size).</p>
+</div>
+<div class="section" id="id242">
+<h5><a class="toc-backref" href="#id967">Semantics:</a><a class="headerlink" href="#id242" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">bitcast</span></tt>‘ instruction converts <tt class="docutils literal"><span class="pre">value</span></tt> to type <tt class="docutils literal"><span class="pre">ty2</span></tt>. It
+is always a <em>no-op cast</em> because no bits change with this
+conversion. The conversion is done as if the <tt class="docutils literal"><span class="pre">value</span></tt> had been stored
+to memory and read back as type <tt class="docutils literal"><span class="pre">ty2</span></tt>. Pointer (or vector of
+pointers) types may only be converted to other pointer (or vector of
+pointers) types with the same address space through this instruction.
+To convert pointers to other types, use the <a class="reference internal" href="#i-inttoptr"><em>inttoptr</em></a>
+or <a class="reference internal" href="#i-ptrtoint"><em>ptrtoint</em></a> instructions first.</p>
+</div>
+<div class="section" id="id243">
+<h5><a class="toc-backref" href="#id968">Example:</a><a class="headerlink" href="#id243" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre>%X = bitcast i8 255 to i8              ; yields i8 :-1
+%Y = bitcast i32* %x to sint*          ; yields sint*:%x
+%Z = bitcast <2 x int> %V to i64;        ; yields i64: %V
+%Z = bitcast <2 x i32*> %V to <2 x i64*> ; yields <2 x i64*>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="addrspacecast-to-instruction">
+<span id="i-addrspacecast"></span><h4><a class="toc-backref" href="#id969">‘<tt class="docutils literal"><span class="pre">addrspacecast</span> <span class="pre">..</span> <span class="pre">to</span></tt>‘ Instruction</a><a class="headerlink" href="#addrspacecast-to-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id244">
+<h5><a class="toc-backref" href="#id970">Syntax:</a><a class="headerlink" href="#id244" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = addrspacecast <pty> <ptrval> to <pty2>       ; yields pty2
+</pre></div>
+</div>
+</div>
+<div class="section" id="id245">
+<h5><a class="toc-backref" href="#id971">Overview:</a><a class="headerlink" href="#id245" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">addrspacecast</span></tt>‘ instruction converts <tt class="docutils literal"><span class="pre">ptrval</span></tt> from <tt class="docutils literal"><span class="pre">pty</span></tt> in
+address space <tt class="docutils literal"><span class="pre">n</span></tt> to type <tt class="docutils literal"><span class="pre">pty2</span></tt> in address space <tt class="docutils literal"><span class="pre">m</span></tt>.</p>
+</div>
+<div class="section" id="id246">
+<h5><a class="toc-backref" href="#id972">Arguments:</a><a class="headerlink" href="#id246" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">addrspacecast</span></tt>‘ instruction takes a pointer or vector of pointer value
+to cast and a pointer type to cast it to, which must have a different
+address space.</p>
+</div>
+<div class="section" id="id247">
+<h5><a class="toc-backref" href="#id973">Semantics:</a><a class="headerlink" href="#id247" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">addrspacecast</span></tt>‘ instruction converts the pointer value
+<tt class="docutils literal"><span class="pre">ptrval</span></tt> to type <tt class="docutils literal"><span class="pre">pty2</span></tt>. It can be a <em>no-op cast</em> or a complex
+value modification, depending on the target and the address space
+pair. Pointer conversions within the same address space must be
+performed with the <tt class="docutils literal"><span class="pre">bitcast</span></tt> instruction. Note that if the address space
+conversion is legal then both result and operand refer to the same memory
+location.</p>
+</div>
+<div class="section" id="id248">
+<h5><a class="toc-backref" href="#id974">Example:</a><a class="headerlink" href="#id248" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre>%X = addrspacecast i32* %x to i32 addrspace(1)*    ; yields i32 addrspace(1)*:%x
+%Y = addrspacecast i32 addrspace(1)* %y to i64 addrspace(2)*    ; yields i64 addrspace(2)*:%y
+%Z = addrspacecast <4 x i32*> %z to <4 x float addrspace(3)*>   ; yields <4 x float addrspace(3)*>:%z
+</pre></div>
+</div>
+</div>
+</div>
+</div>
+<div class="section" id="other-operations">
+<span id="otherops"></span><h3><a class="toc-backref" href="#id975">Other Operations</a><a class="headerlink" href="#other-operations" title="Permalink to this headline">¶</a></h3>
+<p>The instructions in this category are the “miscellaneous” instructions,
+which defy better classification.</p>
+<div class="section" id="icmp-instruction">
+<span id="i-icmp"></span><h4><a class="toc-backref" href="#id976">‘<tt class="docutils literal"><span class="pre">icmp</span></tt>‘ Instruction</a><a class="headerlink" href="#icmp-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id249">
+<h5><a class="toc-backref" href="#id977">Syntax:</a><a class="headerlink" href="#id249" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = icmp <cond> <ty> <op1>, <op2>   ; yields i1 or <N x i1>:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id250">
+<h5><a class="toc-backref" href="#id978">Overview:</a><a class="headerlink" href="#id250" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">icmp</span></tt>‘ instruction returns a boolean value or a vector of
+boolean values based on comparison of its two integer, integer vector,
+pointer, or pointer vector operands.</p>
+</div>
+<div class="section" id="id251">
+<h5><a class="toc-backref" href="#id979">Arguments:</a><a class="headerlink" href="#id251" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">icmp</span></tt>‘ instruction takes three operands. The first operand is
+the condition code indicating the kind of comparison to perform. It is
+not a value, just a keyword. The possible condition code are:</p>
+<ol class="arabic simple">
+<li><tt class="docutils literal"><span class="pre">eq</span></tt>: equal</li>
+<li><tt class="docutils literal"><span class="pre">ne</span></tt>: not equal</li>
+<li><tt class="docutils literal"><span class="pre">ugt</span></tt>: unsigned greater than</li>
+<li><tt class="docutils literal"><span class="pre">uge</span></tt>: unsigned greater or equal</li>
+<li><tt class="docutils literal"><span class="pre">ult</span></tt>: unsigned less than</li>
+<li><tt class="docutils literal"><span class="pre">ule</span></tt>: unsigned less or equal</li>
+<li><tt class="docutils literal"><span class="pre">sgt</span></tt>: signed greater than</li>
+<li><tt class="docutils literal"><span class="pre">sge</span></tt>: signed greater or equal</li>
+<li><tt class="docutils literal"><span class="pre">slt</span></tt>: signed less than</li>
+<li><tt class="docutils literal"><span class="pre">sle</span></tt>: signed less or equal</li>
+</ol>
+<p>The remaining two arguments must be <a class="reference internal" href="#t-integer"><em>integer</em></a> or
+<a class="reference internal" href="#t-pointer"><em>pointer</em></a> or integer <a class="reference internal" href="#t-vector"><em>vector</em></a> typed. They
+must also be identical types.</p>
+</div>
+<div class="section" id="id252">
+<h5><a class="toc-backref" href="#id980">Semantics:</a><a class="headerlink" href="#id252" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">icmp</span></tt>‘ compares <tt class="docutils literal"><span class="pre">op1</span></tt> and <tt class="docutils literal"><span class="pre">op2</span></tt> according to the condition
+code given as <tt class="docutils literal"><span class="pre">cond</span></tt>. The comparison performed always yields either an
+<a class="reference internal" href="#t-integer"><em>i1</em></a> or vector of <tt class="docutils literal"><span class="pre">i1</span></tt> result, as follows:</p>
+<ol class="arabic simple">
+<li><tt class="docutils literal"><span class="pre">eq</span></tt>: yields <tt class="docutils literal"><span class="pre">true</span></tt> if the operands are equal, <tt class="docutils literal"><span class="pre">false</span></tt>
+otherwise. No sign interpretation is necessary or performed.</li>
+<li><tt class="docutils literal"><span class="pre">ne</span></tt>: yields <tt class="docutils literal"><span class="pre">true</span></tt> if the operands are unequal, <tt class="docutils literal"><span class="pre">false</span></tt>
+otherwise. No sign interpretation is necessary or performed.</li>
+<li><tt class="docutils literal"><span class="pre">ugt</span></tt>: interprets the operands as unsigned values and yields
+<tt class="docutils literal"><span class="pre">true</span></tt> if <tt class="docutils literal"><span class="pre">op1</span></tt> is greater than <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">uge</span></tt>: interprets the operands as unsigned values and yields
+<tt class="docutils literal"><span class="pre">true</span></tt> if <tt class="docutils literal"><span class="pre">op1</span></tt> is greater than or equal to <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">ult</span></tt>: interprets the operands as unsigned values and yields
+<tt class="docutils literal"><span class="pre">true</span></tt> if <tt class="docutils literal"><span class="pre">op1</span></tt> is less than <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">ule</span></tt>: interprets the operands as unsigned values and yields
+<tt class="docutils literal"><span class="pre">true</span></tt> if <tt class="docutils literal"><span class="pre">op1</span></tt> is less than or equal to <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">sgt</span></tt>: interprets the operands as signed values and yields <tt class="docutils literal"><span class="pre">true</span></tt>
+if <tt class="docutils literal"><span class="pre">op1</span></tt> is greater than <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">sge</span></tt>: interprets the operands as signed values and yields <tt class="docutils literal"><span class="pre">true</span></tt>
+if <tt class="docutils literal"><span class="pre">op1</span></tt> is greater than or equal to <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">slt</span></tt>: interprets the operands as signed values and yields <tt class="docutils literal"><span class="pre">true</span></tt>
+if <tt class="docutils literal"><span class="pre">op1</span></tt> is less than <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">sle</span></tt>: interprets the operands as signed values and yields <tt class="docutils literal"><span class="pre">true</span></tt>
+if <tt class="docutils literal"><span class="pre">op1</span></tt> is less than or equal to <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+</ol>
+<p>If the operands are <a class="reference internal" href="#t-pointer"><em>pointer</em></a> typed, the pointer values
+are compared as if they were integers.</p>
+<p>If the operands are integer vectors, then they are compared element by
+element. The result is an <tt class="docutils literal"><span class="pre">i1</span></tt> vector with the same number of elements
+as the values being compared. Otherwise, the result is an <tt class="docutils literal"><span class="pre">i1</span></tt>.</p>
+</div>
+<div class="section" id="id253">
+<h5><a class="toc-backref" href="#id981">Example:</a><a class="headerlink" href="#id253" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = icmp eq i32 4, 5          ; yields: result=false
+<result> = icmp ne float* %X, %X     ; yields: result=false
+<result> = icmp ult i16  4, 5        ; yields: result=true
+<result> = icmp sgt i16  4, 5        ; yields: result=false
+<result> = icmp ule i16 -4, 5        ; yields: result=false
+<result> = icmp sge i16  4, 5        ; yields: result=false
+</pre></div>
+</div>
+<p>Note that the code generator does not yet support vector types with the
+<tt class="docutils literal"><span class="pre">icmp</span></tt> instruction.</p>
+</div>
+</div>
+<div class="section" id="fcmp-instruction">
+<span id="i-fcmp"></span><h4><a class="toc-backref" href="#id982">‘<tt class="docutils literal"><span class="pre">fcmp</span></tt>‘ Instruction</a><a class="headerlink" href="#fcmp-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id254">
+<h5><a class="toc-backref" href="#id983">Syntax:</a><a class="headerlink" href="#id254" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = fcmp <cond> <ty> <op1>, <op2>     ; yields i1 or <N x i1>:result
+</pre></div>
+</div>
+</div>
+<div class="section" id="id255">
+<h5><a class="toc-backref" href="#id984">Overview:</a><a class="headerlink" href="#id255" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fcmp</span></tt>‘ instruction returns a boolean value or vector of boolean
+values based on comparison of its operands.</p>
+<p>If the operands are floating point scalars, then the result type is a
+boolean (<a class="reference internal" href="#t-integer"><em>i1</em></a>).</p>
+<p>If the operands are floating point vectors, then the result type is a
+vector of boolean with the same number of elements as the operands being
+compared.</p>
+</div>
+<div class="section" id="id256">
+<h5><a class="toc-backref" href="#id985">Arguments:</a><a class="headerlink" href="#id256" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fcmp</span></tt>‘ instruction takes three operands. The first operand is
+the condition code indicating the kind of comparison to perform. It is
+not a value, just a keyword. The possible condition code are:</p>
+<ol class="arabic simple">
+<li><tt class="docutils literal"><span class="pre">false</span></tt>: no comparison, always returns false</li>
+<li><tt class="docutils literal"><span class="pre">oeq</span></tt>: ordered and equal</li>
+<li><tt class="docutils literal"><span class="pre">ogt</span></tt>: ordered and greater than</li>
+<li><tt class="docutils literal"><span class="pre">oge</span></tt>: ordered and greater than or equal</li>
+<li><tt class="docutils literal"><span class="pre">olt</span></tt>: ordered and less than</li>
+<li><tt class="docutils literal"><span class="pre">ole</span></tt>: ordered and less than or equal</li>
+<li><tt class="docutils literal"><span class="pre">one</span></tt>: ordered and not equal</li>
+<li><tt class="docutils literal"><span class="pre">ord</span></tt>: ordered (no nans)</li>
+<li><tt class="docutils literal"><span class="pre">ueq</span></tt>: unordered or equal</li>
+<li><tt class="docutils literal"><span class="pre">ugt</span></tt>: unordered or greater than</li>
+<li><tt class="docutils literal"><span class="pre">uge</span></tt>: unordered or greater than or equal</li>
+<li><tt class="docutils literal"><span class="pre">ult</span></tt>: unordered or less than</li>
+<li><tt class="docutils literal"><span class="pre">ule</span></tt>: unordered or less than or equal</li>
+<li><tt class="docutils literal"><span class="pre">une</span></tt>: unordered or not equal</li>
+<li><tt class="docutils literal"><span class="pre">uno</span></tt>: unordered (either nans)</li>
+<li><tt class="docutils literal"><span class="pre">true</span></tt>: no comparison, always returns true</li>
+</ol>
+<p><em>Ordered</em> means that neither operand is a QNAN while <em>unordered</em> means
+that either operand may be a QNAN.</p>
+<p>Each of <tt class="docutils literal"><span class="pre">val1</span></tt> and <tt class="docutils literal"><span class="pre">val2</span></tt> arguments must be either a <a class="reference internal" href="#t-floating"><em>floating
+point</em></a> type or a <a class="reference internal" href="#t-vector"><em>vector</em></a> of floating point
+type. They must have identical types.</p>
+</div>
+<div class="section" id="id257">
+<h5><a class="toc-backref" href="#id986">Semantics:</a><a class="headerlink" href="#id257" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">fcmp</span></tt>‘ instruction compares <tt class="docutils literal"><span class="pre">op1</span></tt> and <tt class="docutils literal"><span class="pre">op2</span></tt> according to the
+condition code given as <tt class="docutils literal"><span class="pre">cond</span></tt>. If the operands are vectors, then the
+vectors are compared element by element. Each comparison performed
+always yields an <a class="reference internal" href="#t-integer"><em>i1</em></a> result, as follows:</p>
+<ol class="arabic simple">
+<li><tt class="docutils literal"><span class="pre">false</span></tt>: always yields <tt class="docutils literal"><span class="pre">false</span></tt>, regardless of operands.</li>
+<li><tt class="docutils literal"><span class="pre">oeq</span></tt>: yields <tt class="docutils literal"><span class="pre">true</span></tt> if both operands are not a QNAN and <tt class="docutils literal"><span class="pre">op1</span></tt>
+is equal to <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">ogt</span></tt>: yields <tt class="docutils literal"><span class="pre">true</span></tt> if both operands are not a QNAN and <tt class="docutils literal"><span class="pre">op1</span></tt>
+is greater than <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">oge</span></tt>: yields <tt class="docutils literal"><span class="pre">true</span></tt> if both operands are not a QNAN and <tt class="docutils literal"><span class="pre">op1</span></tt>
+is greater than or equal to <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">olt</span></tt>: yields <tt class="docutils literal"><span class="pre">true</span></tt> if both operands are not a QNAN and <tt class="docutils literal"><span class="pre">op1</span></tt>
+is less than <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">ole</span></tt>: yields <tt class="docutils literal"><span class="pre">true</span></tt> if both operands are not a QNAN and <tt class="docutils literal"><span class="pre">op1</span></tt>
+is less than or equal to <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">one</span></tt>: yields <tt class="docutils literal"><span class="pre">true</span></tt> if both operands are not a QNAN and <tt class="docutils literal"><span class="pre">op1</span></tt>
+is not equal to <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">ord</span></tt>: yields <tt class="docutils literal"><span class="pre">true</span></tt> if both operands are not a QNAN.</li>
+<li><tt class="docutils literal"><span class="pre">ueq</span></tt>: yields <tt class="docutils literal"><span class="pre">true</span></tt> if either operand is a QNAN or <tt class="docutils literal"><span class="pre">op1</span></tt> is
+equal to <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">ugt</span></tt>: yields <tt class="docutils literal"><span class="pre">true</span></tt> if either operand is a QNAN or <tt class="docutils literal"><span class="pre">op1</span></tt> is
+greater than <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">uge</span></tt>: yields <tt class="docutils literal"><span class="pre">true</span></tt> if either operand is a QNAN or <tt class="docutils literal"><span class="pre">op1</span></tt> is
+greater than or equal to <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">ult</span></tt>: yields <tt class="docutils literal"><span class="pre">true</span></tt> if either operand is a QNAN or <tt class="docutils literal"><span class="pre">op1</span></tt> is
+less than <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">ule</span></tt>: yields <tt class="docutils literal"><span class="pre">true</span></tt> if either operand is a QNAN or <tt class="docutils literal"><span class="pre">op1</span></tt> is
+less than or equal to <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">une</span></tt>: yields <tt class="docutils literal"><span class="pre">true</span></tt> if either operand is a QNAN or <tt class="docutils literal"><span class="pre">op1</span></tt> is
+not equal to <tt class="docutils literal"><span class="pre">op2</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">uno</span></tt>: yields <tt class="docutils literal"><span class="pre">true</span></tt> if either operand is a QNAN.</li>
+<li><tt class="docutils literal"><span class="pre">true</span></tt>: always yields <tt class="docutils literal"><span class="pre">true</span></tt>, regardless of operands.</li>
+</ol>
+</div>
+<div class="section" id="id258">
+<h5><a class="toc-backref" href="#id987">Example:</a><a class="headerlink" href="#id258" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><result> = fcmp oeq float 4.0, 5.0    ; yields: result=false
+<result> = fcmp one float 4.0, 5.0    ; yields: result=true
+<result> = fcmp olt float 4.0, 5.0    ; yields: result=true
+<result> = fcmp ueq double 1.0, 2.0   ; yields: result=false
+</pre></div>
+</div>
+<p>Note that the code generator does not yet support vector types with the
+<tt class="docutils literal"><span class="pre">fcmp</span></tt> instruction.</p>
+</div>
+</div>
+<div class="section" id="phi-instruction">
+<span id="i-phi"></span><h4><a class="toc-backref" href="#id988">‘<tt class="docutils literal"><span class="pre">phi</span></tt>‘ Instruction</a><a class="headerlink" href="#phi-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id259">
+<h5><a class="toc-backref" href="#id989">Syntax:</a><a class="headerlink" href="#id259" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = phi <ty> [ <val0>, <label0>], ...
+</pre></div>
+</div>
+</div>
+<div class="section" id="id260">
+<h5><a class="toc-backref" href="#id990">Overview:</a><a class="headerlink" href="#id260" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">phi</span></tt>‘ instruction is used to implement the φ node in the SSA
+graph representing the function.</p>
+</div>
+<div class="section" id="id261">
+<h5><a class="toc-backref" href="#id991">Arguments:</a><a class="headerlink" href="#id261" title="Permalink to this headline">¶</a></h5>
+<p>The type of the incoming values is specified with the first type field.
+After this, the ‘<tt class="docutils literal"><span class="pre">phi</span></tt>‘ instruction takes a list of pairs as
+arguments, with one pair for each predecessor basic block of the current
+block. Only values of <a class="reference internal" href="#t-firstclass"><em>first class</em></a> type may be used as
+the value arguments to the PHI node. Only labels may be used as the
+label arguments.</p>
+<p>There must be no non-phi instructions between the start of a basic block
+and the PHI instructions: i.e. PHI instructions must be first in a basic
+block.</p>
+<p>For the purposes of the SSA form, the use of each incoming value is
+deemed to occur on the edge from the corresponding predecessor block to
+the current block (but after any definition of an ‘<tt class="docutils literal"><span class="pre">invoke</span></tt>‘
+instruction’s return value on the same edge).</p>
+</div>
+<div class="section" id="id262">
+<h5><a class="toc-backref" href="#id992">Semantics:</a><a class="headerlink" href="#id262" title="Permalink to this headline">¶</a></h5>
+<p>At runtime, the ‘<tt class="docutils literal"><span class="pre">phi</span></tt>‘ instruction logically takes on the value
+specified by the pair corresponding to the predecessor basic block that
+executed just prior to the current block.</p>
+</div>
+<div class="section" id="id263">
+<h5><a class="toc-backref" href="#id993">Example:</a><a class="headerlink" href="#id263" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nl">Loop:</span>       <span class="c">; Infinite loop that counts from 0 on up...</span>
+  <span class="nv">%indvar</span> <span class="p">=</span> <span class="k">phi</span> <span class="k">i32</span> <span class="p">[</span> <span class="m">0</span><span class="p">,</span> <span class="nv">%LoopHeader</span> <span class="p">],</span> <span class="p">[</span> <span class="nv">%nextindvar</span><span class="p">,</span> <span class="nv">%Loop</span> <span class="p">]</span>
+  <span class="nv">%nextindvar</span> <span class="p">=</span> <span class="k">add</span> <span class="k">i32</span> <span class="nv">%indvar</span><span class="p">,</span> <span class="m">1</span>
+  <span class="k">br</span> <span class="kt">label</span> <span class="nv">%Loop</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="select-instruction">
+<span id="i-select"></span><h4><a class="toc-backref" href="#id994">‘<tt class="docutils literal"><span class="pre">select</span></tt>‘ Instruction</a><a class="headerlink" href="#select-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id264">
+<h5><a class="toc-backref" href="#id995">Syntax:</a><a class="headerlink" href="#id264" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = select selty <cond>, <ty> <val1>, <ty> <val2>             ; yields ty
+
+selty is either i1 or {<N x i1>}
+</pre></div>
+</div>
+</div>
+<div class="section" id="id265">
+<h5><a class="toc-backref" href="#id996">Overview:</a><a class="headerlink" href="#id265" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">select</span></tt>‘ instruction is used to choose one value based on a
+condition, without IR-level branching.</p>
+</div>
+<div class="section" id="id266">
+<h5><a class="toc-backref" href="#id997">Arguments:</a><a class="headerlink" href="#id266" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">select</span></tt>‘ instruction requires an ‘i1’ value or a vector of ‘i1’
+values indicating the condition, and two values of the same <a class="reference internal" href="#t-firstclass"><em>first
+class</em></a> type. If the val1/val2 are vectors and the
+condition is a scalar, then entire vectors are selected, not individual
+elements.</p>
+</div>
+<div class="section" id="id267">
+<h5><a class="toc-backref" href="#id998">Semantics:</a><a class="headerlink" href="#id267" title="Permalink to this headline">¶</a></h5>
+<p>If the condition is an i1 and it evaluates to 1, the instruction returns
+the first value argument; otherwise, it returns the second value
+argument.</p>
+<p>If the condition is a vector of i1, then the value arguments must be
+vectors of the same size, and the selection is done element by element.</p>
+</div>
+<div class="section" id="id268">
+<h5><a class="toc-backref" href="#id999">Example:</a><a class="headerlink" href="#id268" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%X</span> <span class="p">=</span> <span class="k">select</span> <span class="k">i1</span> <span class="k">true</span><span class="p">,</span> <span class="k">i8</span> <span class="m">17</span><span class="p">,</span> <span class="k">i8</span> <span class="m">42</span>          <span class="c">; yields i8:17</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="call-instruction">
+<span id="i-call"></span><h4><a class="toc-backref" href="#id1000">‘<tt class="docutils literal"><span class="pre">call</span></tt>‘ Instruction</a><a class="headerlink" href="#call-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id269">
+<h5><a class="toc-backref" href="#id1001">Syntax:</a><a class="headerlink" href="#id269" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><result> = [tail | musttail] call [cconv] [ret attrs] <ty> [<fnty>*] <fnptrval>(<function args>) [fn attrs]
+</pre></div>
+</div>
+</div>
+<div class="section" id="id270">
+<h5><a class="toc-backref" href="#id1002">Overview:</a><a class="headerlink" href="#id270" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">call</span></tt>‘ instruction represents a simple function call.</p>
+</div>
+<div class="section" id="id271">
+<h5><a class="toc-backref" href="#id1003">Arguments:</a><a class="headerlink" href="#id271" title="Permalink to this headline">¶</a></h5>
+<p>This instruction requires several arguments:</p>
+<ol class="arabic">
+<li><p class="first">The optional <tt class="docutils literal"><span class="pre">tail</span></tt> and <tt class="docutils literal"><span class="pre">musttail</span></tt> markers indicate that the optimizers
+should perform tail call optimization.  The <tt class="docutils literal"><span class="pre">tail</span></tt> marker is a hint that
+<a class="reference external" href="CodeGenerator.html#sibcallopt">can be ignored</a>.  The <tt class="docutils literal"><span class="pre">musttail</span></tt> marker
+means that the call must be tail call optimized in order for the program to
+be correct.  The <tt class="docutils literal"><span class="pre">musttail</span></tt> marker provides these guarantees:</p>
+<ol class="arabic simple">
+<li>The call will not cause unbounded stack growth if it is part of a
+recursive cycle in the call graph.</li>
+<li>Arguments with the <a class="reference internal" href="#attr-inalloca"><em>inalloca</em></a> attribute are
+forwarded in place.</li>
+</ol>
+<p>Both markers imply that the callee does not access allocas or varargs from
+the caller.  Calls marked <tt class="docutils literal"><span class="pre">musttail</span></tt> must obey the following additional
+rules:</p>
+<ul class="simple">
+<li>The call must immediately precede a <a class="reference internal" href="#i-ret"><em>ret</em></a> instruction,
+or a pointer bitcast followed by a ret instruction.</li>
+<li>The ret instruction must return the (possibly bitcasted) value
+produced by the call or void.</li>
+<li>The caller and callee prototypes must match.  Pointer types of
+parameters or return types may differ in pointee type, but not
+in address space.</li>
+<li>The calling conventions of the caller and callee must match.</li>
+<li>All ABI-impacting function attributes, such as sret, byval, inreg,
+returned, and inalloca, must match.</li>
+<li>The callee must be varargs iff the caller is varargs. Bitcasting a
+non-varargs function to the appropriate varargs type is legal so
+long as the non-varargs prefixes obey the other rules.</li>
+</ul>
+<p>Tail call optimization for calls marked <tt class="docutils literal"><span class="pre">tail</span></tt> is guaranteed to occur if
+the following conditions are met:</p>
+<ul class="simple">
+<li>Caller and callee both have the calling convention <tt class="docutils literal"><span class="pre">fastcc</span></tt>.</li>
+<li>The call is in tail position (ret immediately follows call and ret
+uses value of call or is void).</li>
+<li>Option <tt class="docutils literal"><span class="pre">-tailcallopt</span></tt> is enabled, or
+<tt class="docutils literal"><span class="pre">llvm::GuaranteedTailCallOpt</span></tt> is <tt class="docutils literal"><span class="pre">true</span></tt>.</li>
+<li><a class="reference external" href="CodeGenerator.html#tailcallopt">Platform-specific constraints are
+met.</a></li>
+</ul>
+</li>
+<li><p class="first">The optional “cconv” marker indicates which <a class="reference internal" href="#callingconv"><em>calling
+convention</em></a> the call should use. If none is
+specified, the call defaults to using C calling conventions. The
+calling convention of the call must match the calling convention of
+the target function, or else the behavior is undefined.</p>
+</li>
+<li><p class="first">The optional <a class="reference internal" href="#paramattrs"><em>Parameter Attributes</em></a> list for return
+values. Only ‘<tt class="docutils literal"><span class="pre">zeroext</span></tt>‘, ‘<tt class="docutils literal"><span class="pre">signext</span></tt>‘, and ‘<tt class="docutils literal"><span class="pre">inreg</span></tt>‘ attributes
+are valid here.</p>
+</li>
+<li><p class="first">‘<tt class="docutils literal"><span class="pre">ty</span></tt>‘: the type of the call instruction itself which is also the
+type of the return value. Functions that return no value are marked
+<tt class="docutils literal"><span class="pre">void</span></tt>.</p>
+</li>
+<li><p class="first">‘<tt class="docutils literal"><span class="pre">fnty</span></tt>‘: shall be the signature of the pointer to function value
+being invoked. The argument types must match the types implied by
+this signature. This type can be omitted if the function is not
+varargs and if the function type does not return a pointer to a
+function.</p>
+</li>
+<li><p class="first">‘<tt class="docutils literal"><span class="pre">fnptrval</span></tt>‘: An LLVM value containing a pointer to a function to
+be invoked. In most cases, this is a direct function invocation, but
+indirect <tt class="docutils literal"><span class="pre">call</span></tt>‘s are just as possible, calling an arbitrary pointer
+to function value.</p>
+</li>
+<li><p class="first">‘<tt class="docutils literal"><span class="pre">function</span> <span class="pre">args</span></tt>‘: argument list whose types match the function
+signature argument types and parameter attributes. All arguments must
+be of <a class="reference internal" href="#t-firstclass"><em>first class</em></a> type. If the function signature
+indicates the function accepts a variable number of arguments, the
+extra arguments can be specified.</p>
+</li>
+<li><p class="first">The optional <a class="reference internal" href="#fnattrs"><em>function attributes</em></a> list. Only
+‘<tt class="docutils literal"><span class="pre">noreturn</span></tt>‘, ‘<tt class="docutils literal"><span class="pre">nounwind</span></tt>‘, ‘<tt class="docutils literal"><span class="pre">readonly</span></tt>‘ and ‘<tt class="docutils literal"><span class="pre">readnone</span></tt>‘
+attributes are valid here.</p>
+</li>
+</ol>
+</div>
+<div class="section" id="id272">
+<h5><a class="toc-backref" href="#id1004">Semantics:</a><a class="headerlink" href="#id272" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">call</span></tt>‘ instruction is used to cause control flow to transfer to
+a specified function, with its incoming arguments bound to the specified
+values. Upon a ‘<tt class="docutils literal"><span class="pre">ret</span></tt>‘ instruction in the called function, control
+flow continues with the instruction after the function call, and the
+return value of the function is bound to the result argument.</p>
+</div>
+<div class="section" id="id273">
+<h5><a class="toc-backref" href="#id1005">Example:</a><a class="headerlink" href="#id273" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%retval</span> <span class="p">=</span> <span class="k">call</span> <span class="k">i32</span> <span class="vg">@test</span><span class="p">(</span><span class="k">i32</span> <span class="nv">%argc</span><span class="p">)</span>
+<span class="k">call</span> <span class="k">i32</span> <span class="p">(</span><span class="k">i8</span><span class="p">*,</span> <span class="p">...)*</span> <span class="vg">@printf</span><span class="p">(</span><span class="k">i8</span><span class="p">*</span> <span class="nv">%msg</span><span class="p">,</span> <span class="k">i32</span> <span class="m">12</span><span class="p">,</span> <span class="k">i8</span> <span class="m">42</span><span class="p">)</span>        <span class="c">; yields i32</span>
+<span class="nv">%X</span> <span class="p">=</span> <span class="k">tail</span> <span class="k">call</span> <span class="k">i32</span> <span class="vg">@foo</span><span class="p">()</span>                                    <span class="c">; yields i32</span>
+<span class="nv">%Y</span> <span class="p">=</span> <span class="k">tail</span> <span class="k">call</span> <span class="k">fastcc</span> <span class="k">i32</span> <span class="vg">@foo</span><span class="p">()</span>  <span class="c">; yields i32</span>
+<span class="k">call</span> <span class="kt">void</span> <span class="nv">%foo</span><span class="p">(</span><span class="k">i8</span> <span class="m">97</span> <span class="k">signext</span><span class="p">)</span>
+
+<span class="nv">%struct.A</span> <span class="p">=</span> <span class="k">type</span> <span class="p">{</span> <span class="k">i32</span><span class="p">,</span> <span class="k">i8</span> <span class="p">}</span>
+<span class="nv">%r</span> <span class="p">=</span> <span class="k">call</span> <span class="nv">%struct.A</span> <span class="vg">@foo</span><span class="p">()</span>                        <span class="c">; yields { i32, i8 }</span>
+<span class="nv">%gr</span> <span class="p">=</span> <span class="k">extractvalue</span> <span class="nv">%struct.A</span> <span class="nv">%r</span><span class="p">,</span> <span class="m">0</span>                <span class="c">; yields i32</span>
+<span class="nv">%gr1</span> <span class="p">=</span> <span class="k">extractvalue</span> <span class="nv">%struct.A</span> <span class="nv">%r</span><span class="p">,</span> <span class="m">1</span>               <span class="c">; yields i8</span>
+<span class="nv">%Z</span> <span class="p">=</span> <span class="k">call</span> <span class="kt">void</span> <span class="vg">@foo</span><span class="p">()</span> <span class="k">noreturn</span>                    <span class="c">; indicates that %foo never returns normally</span>
+<span class="nv">%ZZ</span> <span class="p">=</span> <span class="k">call</span> <span class="k">zeroext</span> <span class="k">i32</span> <span class="vg">@bar</span><span class="p">()</span>                     <span class="c">; Return value is %zero extended</span>
+</pre></div>
+</div>
+<p>llvm treats calls to some functions with names and arguments that match
+the standard C99 library as being the C99 library functions, and may
+perform optimizations or generate code for them under that assumption.
+This is something we’d like to change in the future to provide better
+support for freestanding environments and non-C-based languages.</p>
+</div>
+</div>
+<div class="section" id="va-arg-instruction">
+<span id="i-va-arg"></span><h4><a class="toc-backref" href="#id1006">‘<tt class="docutils literal"><span class="pre">va_arg</span></tt>‘ Instruction</a><a class="headerlink" href="#va-arg-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id274">
+<h5><a class="toc-backref" href="#id1007">Syntax:</a><a class="headerlink" href="#id274" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><resultval> = va_arg <va_list*> <arglist>, <argty>
+</pre></div>
+</div>
+</div>
+<div class="section" id="id275">
+<h5><a class="toc-backref" href="#id1008">Overview:</a><a class="headerlink" href="#id275" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">va_arg</span></tt>‘ instruction is used to access arguments passed through
+the “variable argument” area of a function call. It is used to implement
+the <tt class="docutils literal"><span class="pre">va_arg</span></tt> macro in C.</p>
+</div>
+<div class="section" id="id276">
+<h5><a class="toc-backref" href="#id1009">Arguments:</a><a class="headerlink" href="#id276" title="Permalink to this headline">¶</a></h5>
+<p>This instruction takes a <tt class="docutils literal"><span class="pre">va_list*</span></tt> value and the type of the
+argument. It returns a value of the specified argument type and
+increments the <tt class="docutils literal"><span class="pre">va_list</span></tt> to point to the next argument. The actual
+type of <tt class="docutils literal"><span class="pre">va_list</span></tt> is target specific.</p>
+</div>
+<div class="section" id="id277">
+<h5><a class="toc-backref" href="#id1010">Semantics:</a><a class="headerlink" href="#id277" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">va_arg</span></tt>‘ instruction loads an argument of the specified type
+from the specified <tt class="docutils literal"><span class="pre">va_list</span></tt> and causes the <tt class="docutils literal"><span class="pre">va_list</span></tt> to point to
+the next argument. For more information, see the variable argument
+handling <a class="reference internal" href="#int-varargs"><em>Intrinsic Functions</em></a>.</p>
+<p>It is legal for this instruction to be called in a function which does
+not take a variable number of arguments, for example, the <tt class="docutils literal"><span class="pre">vfprintf</span></tt>
+function.</p>
+<p><tt class="docutils literal"><span class="pre">va_arg</span></tt> is an LLVM instruction instead of an <a class="reference internal" href="#intrinsics"><em>intrinsic
+function</em></a> because it takes a type as an argument.</p>
+</div>
+<div class="section" id="id278">
+<h5><a class="toc-backref" href="#id1011">Example:</a><a class="headerlink" href="#id278" title="Permalink to this headline">¶</a></h5>
+<p>See the <a class="reference internal" href="#int-varargs"><em>variable argument processing</em></a> section.</p>
+<p>Note that the code generator does not yet fully support va_arg on many
+targets. Also, it does not currently support va_arg with aggregate
+types on any target.</p>
+</div>
+</div>
+<div class="section" id="landingpad-instruction">
+<span id="i-landingpad"></span><h4><a class="toc-backref" href="#id1012">‘<tt class="docutils literal"><span class="pre">landingpad</span></tt>‘ Instruction</a><a class="headerlink" href="#landingpad-instruction" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id279">
+<h5><a class="toc-backref" href="#id1013">Syntax:</a><a class="headerlink" href="#id279" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre><resultval> = landingpad <resultty> personality <type> <pers_fn> <clause>+
+<resultval> = landingpad <resultty> personality <type> <pers_fn> cleanup <clause>*
+
+<clause> := catch <type> <value>
+<clause> := filter <array constant type> <array constant>
+</pre></div>
+</div>
+</div>
+<div class="section" id="id280">
+<h5><a class="toc-backref" href="#id1014">Overview:</a><a class="headerlink" href="#id280" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">landingpad</span></tt>‘ instruction is used by <a class="reference external" href="ExceptionHandling.html#overview">LLVM’s exception handling
+system</a> to specify that a basic block
+is a landing pad — one where the exception lands, and corresponds to the
+code found in the <tt class="docutils literal"><span class="pre">catch</span></tt> portion of a <tt class="docutils literal"><span class="pre">try</span></tt>/<tt class="docutils literal"><span class="pre">catch</span></tt> sequence. It
+defines values supplied by the personality function (<tt class="docutils literal"><span class="pre">pers_fn</span></tt>) upon
+re-entry to the function. The <tt class="docutils literal"><span class="pre">resultval</span></tt> has the type <tt class="docutils literal"><span class="pre">resultty</span></tt>.</p>
+</div>
+<div class="section" id="id281">
+<h5><a class="toc-backref" href="#id1015">Arguments:</a><a class="headerlink" href="#id281" title="Permalink to this headline">¶</a></h5>
+<p>This instruction takes a <tt class="docutils literal"><span class="pre">pers_fn</span></tt> value. This is the personality
+function associated with the unwinding mechanism. The optional
+<tt class="docutils literal"><span class="pre">cleanup</span></tt> flag indicates that the landing pad block is a cleanup.</p>
+<p>A <tt class="docutils literal"><span class="pre">clause</span></tt> begins with the clause type — <tt class="docutils literal"><span class="pre">catch</span></tt> or <tt class="docutils literal"><span class="pre">filter</span></tt> — and
+contains the global variable representing the “type” that may be caught
+or filtered respectively. Unlike the <tt class="docutils literal"><span class="pre">catch</span></tt> clause, the <tt class="docutils literal"><span class="pre">filter</span></tt>
+clause takes an array constant as its argument. Use
+“<tt class="docutils literal"><span class="pre">[0</span> <span class="pre">x</span> <span class="pre">i8**]</span> <span class="pre">undef</span></tt>” for a filter which cannot throw. The
+‘<tt class="docutils literal"><span class="pre">landingpad</span></tt>‘ instruction must contain <em>at least</em> one <tt class="docutils literal"><span class="pre">clause</span></tt> or
+the <tt class="docutils literal"><span class="pre">cleanup</span></tt> flag.</p>
+</div>
+<div class="section" id="id282">
+<h5><a class="toc-backref" href="#id1016">Semantics:</a><a class="headerlink" href="#id282" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">landingpad</span></tt>‘ instruction defines the values which are set by the
+personality function (<tt class="docutils literal"><span class="pre">pers_fn</span></tt>) upon re-entry to the function, and
+therefore the “result type” of the <tt class="docutils literal"><span class="pre">landingpad</span></tt> instruction. As with
+calling conventions, how the personality function results are
+represented in LLVM IR is target specific.</p>
+<p>The clauses are applied in order from top to bottom. If two
+<tt class="docutils literal"><span class="pre">landingpad</span></tt> instructions are merged together through inlining, the
+clauses from the calling function are appended to the list of clauses.
+When the call stack is being unwound due to an exception being thrown,
+the exception is compared against each <tt class="docutils literal"><span class="pre">clause</span></tt> in turn. If it doesn’t
+match any of the clauses, and the <tt class="docutils literal"><span class="pre">cleanup</span></tt> flag is not set, then
+unwinding continues further up the call stack.</p>
+<p>The <tt class="docutils literal"><span class="pre">landingpad</span></tt> instruction has several restrictions:</p>
+<ul class="simple">
+<li>A landing pad block is a basic block which is the unwind destination
+of an ‘<tt class="docutils literal"><span class="pre">invoke</span></tt>‘ instruction.</li>
+<li>A landing pad block must have a ‘<tt class="docutils literal"><span class="pre">landingpad</span></tt>‘ instruction as its
+first non-PHI instruction.</li>
+<li>There can be only one ‘<tt class="docutils literal"><span class="pre">landingpad</span></tt>‘ instruction within the landing
+pad block.</li>
+<li>A basic block that is not a landing pad block may not include a
+‘<tt class="docutils literal"><span class="pre">landingpad</span></tt>‘ instruction.</li>
+<li>All ‘<tt class="docutils literal"><span class="pre">landingpad</span></tt>‘ instructions in a function must have the same
+personality function.</li>
+</ul>
+</div>
+<div class="section" id="id283">
+<h5><a class="toc-backref" href="#id1017">Example:</a><a class="headerlink" href="#id283" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre>;; A landing pad which can catch an integer.
+%res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
+         catch i8** @_ZTIi
+;; A landing pad that is a cleanup.
+%res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
+         cleanup
+;; A landing pad which can catch an integer and can only throw a double.
+%res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
+         catch i8** @_ZTIi
+         filter [1 x i8**] [@_ZTId]
+</pre></div>
+</div>
+</div>
+</div>
+</div>
+</div>
+<div class="section" id="intrinsic-functions">
+<span id="intrinsics"></span><h2><a class="toc-backref" href="#id1018">Intrinsic Functions</a><a class="headerlink" href="#intrinsic-functions" title="Permalink to this headline">¶</a></h2>
+<p>LLVM supports the notion of an “intrinsic function”. These functions
+have well known names and semantics and are required to follow certain
+restrictions. Overall, these intrinsics represent an extension mechanism
+for the LLVM language that does not require changing all of the
+transformations in LLVM when adding to the language (or the bitcode
+reader/writer, the parser, etc...).</p>
+<p>Intrinsic function names must all start with an “<tt class="docutils literal"><span class="pre">llvm.</span></tt>” prefix. This
+prefix is reserved in LLVM for intrinsic names; thus, function names may
+not begin with this prefix. Intrinsic functions must always be external
+functions: you cannot define the body of intrinsic functions. Intrinsic
+functions may only be used in call or invoke instructions: it is illegal
+to take the address of an intrinsic function. Additionally, because
+intrinsic functions are part of the LLVM language, it is required if any
+are added that they be documented here.</p>
+<p>Some intrinsic functions can be overloaded, i.e., the intrinsic
+represents a family of functions that perform the same operation but on
+different data types. Because LLVM can represent over 8 million
+different integer types, overloading is used commonly to allow an
+intrinsic function to operate on any integer type. One or more of the
+argument types or the result type can be overloaded to accept any
+integer type. Argument types may also be defined as exactly matching a
+previous argument’s type or the result type. This allows an intrinsic
+function which accepts multiple arguments, but needs all of them to be
+of the same type, to only be overloaded with respect to a single
+argument or the result.</p>
+<p>Overloaded intrinsics will have the names of its overloaded argument
+types encoded into its function name, each preceded by a period. Only
+those types which are overloaded result in a name suffix. Arguments
+whose type is matched against another type do not. For example, the
+<tt class="docutils literal"><span class="pre">llvm.ctpop</span></tt> function can take an integer of any width and returns an
+integer of exactly the same integer width. This leads to a family of
+functions such as <tt class="docutils literal"><span class="pre">i8</span> <span class="pre">@llvm.ctpop.i8(i8</span> <span class="pre">%val)</span></tt> and
+<tt class="docutils literal"><span class="pre">i29</span> <span class="pre">@llvm.ctpop.i29(i29</span> <span class="pre">%val)</span></tt>. Only one type, the return type, is
+overloaded, and only one type suffix is required. Because the argument’s
+type is matched against the return type, it does not require its own
+name suffix.</p>
+<p>To learn how to add an intrinsic function, please see the <a class="reference external" href="ExtendingLLVM.html">Extending
+LLVM Guide</a>.</p>
+<div class="section" id="variable-argument-handling-intrinsics">
+<span id="int-varargs"></span><h3><a class="toc-backref" href="#id1019">Variable Argument Handling Intrinsics</a><a class="headerlink" href="#variable-argument-handling-intrinsics" title="Permalink to this headline">¶</a></h3>
+<p>Variable argument support is defined in LLVM with the
+<a class="reference internal" href="#i-va-arg"><em>va_arg</em></a> instruction and these three intrinsic
+functions. These functions are related to the similarly named macros
+defined in the <tt class="docutils literal"><span class="pre"><stdarg.h></span></tt> header file.</p>
+<p>All of these functions operate on arguments that use a target-specific
+value type “<tt class="docutils literal"><span class="pre">va_list</span></tt>”. The LLVM assembly language reference manual
+does not define what this type is, so all transformations should be
+prepared to handle these functions regardless of the type used.</p>
+<p>This example shows how the <a class="reference internal" href="#i-va-arg"><em>va_arg</em></a> instruction and the
+variable argument handling intrinsic functions are used.</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="c">; This struct is different for every platform. For most platforms,</span>
+<span class="c">; it is merely an i8*.</span>
+<span class="nv">%struct.va_list</span> <span class="p">=</span> <span class="k">type</span> <span class="p">{</span> <span class="k">i8</span><span class="p">*</span> <span class="p">}</span>
+
+<span class="c">; For Unix x86_64 platforms, va_list is the following struct:</span>
+<span class="c">; %struct.va_list = type { i32, i32, i8*, i8* }</span>
+
+<span class="k">define</span> <span class="k">i32</span> <span class="vg">@test</span><span class="p">(</span><span class="k">i32</span> <span class="nv">%X</span><span class="p">,</span> <span class="p">...)</span> <span class="p">{</span>
+  <span class="c">; Initialize variable argument processing</span>
+  <span class="nv">%ap</span> <span class="p">=</span> <span class="k">alloca</span> <span class="nv">%struct.va_list</span>
+  <span class="nv">%ap2</span> <span class="p">=</span> <span class="k">bitcast</span> <span class="nv">%struct.va_list</span><span class="p">*</span> <span class="nv">%ap</span> <span class="k">to</span> <span class="k">i8</span><span class="p">*</span>
+  <span class="k">call</span> <span class="kt">void</span> <span class="vg">@llvm.va_start</span><span class="p">(</span><span class="k">i8</span><span class="p">*</span> <span class="nv">%ap2</span><span class="p">)</span>
+
+  <span class="c">; Read a single integer argument</span>
+  <span class="nv">%tmp</span> <span class="p">=</span> <span class="k">va_arg</span> <span class="k">i8</span><span class="p">*</span> <span class="nv">%ap2</span><span class="p">,</span> <span class="k">i32</span>
+
+  <span class="c">; Demonstrate usage of llvm.va_copy and llvm.va_end</span>
+  <span class="nv">%aq</span> <span class="p">=</span> <span class="k">alloca</span> <span class="k">i8</span><span class="p">*</span>
+  <span class="nv">%aq2</span> <span class="p">=</span> <span class="k">bitcast</span> <span class="k">i8</span><span class="p">**</span> <span class="nv">%aq</span> <span class="k">to</span> <span class="k">i8</span><span class="p">*</span>
+  <span class="k">call</span> <span class="kt">void</span> <span class="vg">@llvm.va_copy</span><span class="p">(</span><span class="k">i8</span><span class="p">*</span> <span class="nv">%aq2</span><span class="p">,</span> <span class="k">i8</span><span class="p">*</span> <span class="nv">%ap2</span><span class="p">)</span>
+  <span class="k">call</span> <span class="kt">void</span> <span class="vg">@llvm.va_end</span><span class="p">(</span><span class="k">i8</span><span class="p">*</span> <span class="nv">%aq2</span><span class="p">)</span>
+
+  <span class="c">; Stop processing of arguments.</span>
+  <span class="k">call</span> <span class="kt">void</span> <span class="vg">@llvm.va_end</span><span class="p">(</span><span class="k">i8</span><span class="p">*</span> <span class="nv">%ap2</span><span class="p">)</span>
+  <span class="k">ret</span> <span class="k">i32</span> <span class="nv">%tmp</span>
+<span class="p">}</span>
+
+<span class="k">declare</span> <span class="kt">void</span> <span class="vg">@llvm.va_start</span><span class="p">(</span><span class="k">i8</span><span class="p">*)</span>
+<span class="k">declare</span> <span class="kt">void</span> <span class="vg">@llvm.va_copy</span><span class="p">(</span><span class="k">i8</span><span class="p">*,</span> <span class="k">i8</span><span class="p">*)</span>
+<span class="k">declare</span> <span class="kt">void</span> <span class="vg">@llvm.va_end</span><span class="p">(</span><span class="k">i8</span><span class="p">*)</span>
+</pre></div>
+</div>
+<div class="section" id="llvm-va-start-intrinsic">
+<span id="int-va-start"></span><h4><a class="toc-backref" href="#id1020">‘<tt class="docutils literal"><span class="pre">llvm.va_start</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-va-start-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id284">
+<h5><a class="toc-backref" href="#id1021">Syntax:</a><a class="headerlink" href="#id284" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.va_start(i8* <arglist>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id285">
+<h5><a class="toc-backref" href="#id1022">Overview:</a><a class="headerlink" href="#id285" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.va_start</span></tt>‘ intrinsic initializes <tt class="docutils literal"><span class="pre">*<arglist></span></tt> for
+subsequent use by <tt class="docutils literal"><span class="pre">va_arg</span></tt>.</p>
+</div>
+<div class="section" id="id286">
+<h5><a class="toc-backref" href="#id1023">Arguments:</a><a class="headerlink" href="#id286" title="Permalink to this headline">¶</a></h5>
+<p>The argument is a pointer to a <tt class="docutils literal"><span class="pre">va_list</span></tt> element to initialize.</p>
+</div>
+<div class="section" id="id287">
+<h5><a class="toc-backref" href="#id1024">Semantics:</a><a class="headerlink" href="#id287" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.va_start</span></tt>‘ intrinsic works just like the <tt class="docutils literal"><span class="pre">va_start</span></tt> macro
+available in C. In a target-dependent way, it initializes the
+<tt class="docutils literal"><span class="pre">va_list</span></tt> element to which the argument points, so that the next call
+to <tt class="docutils literal"><span class="pre">va_arg</span></tt> will produce the first variable argument passed to the
+function. Unlike the C <tt class="docutils literal"><span class="pre">va_start</span></tt> macro, this intrinsic does not need
+to know the last argument of the function as the compiler can figure
+that out.</p>
+</div>
+</div>
+<div class="section" id="llvm-va-end-intrinsic">
+<h4><a class="toc-backref" href="#id1025">‘<tt class="docutils literal"><span class="pre">llvm.va_end</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-va-end-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id288">
+<h5><a class="toc-backref" href="#id1026">Syntax:</a><a class="headerlink" href="#id288" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.va_end(i8* <arglist>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id289">
+<h5><a class="toc-backref" href="#id1027">Overview:</a><a class="headerlink" href="#id289" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.va_end</span></tt>‘ intrinsic destroys <tt class="docutils literal"><span class="pre">*<arglist></span></tt>, which has been
+initialized previously with <tt class="docutils literal"><span class="pre">llvm.va_start</span></tt> or <tt class="docutils literal"><span class="pre">llvm.va_copy</span></tt>.</p>
+</div>
+<div class="section" id="id290">
+<h5><a class="toc-backref" href="#id1028">Arguments:</a><a class="headerlink" href="#id290" title="Permalink to this headline">¶</a></h5>
+<p>The argument is a pointer to a <tt class="docutils literal"><span class="pre">va_list</span></tt> to destroy.</p>
+</div>
+<div class="section" id="id291">
+<h5><a class="toc-backref" href="#id1029">Semantics:</a><a class="headerlink" href="#id291" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.va_end</span></tt>‘ intrinsic works just like the <tt class="docutils literal"><span class="pre">va_end</span></tt> macro
+available in C. In a target-dependent way, it destroys the <tt class="docutils literal"><span class="pre">va_list</span></tt>
+element to which the argument points. Calls to
+<a class="reference internal" href="#int-va-start"><em>llvm.va_start</em></a> and
+<a class="reference internal" href="#int-va-copy"><em>llvm.va_copy</em></a> must be matched exactly with calls to
+<tt class="docutils literal"><span class="pre">llvm.va_end</span></tt>.</p>
+</div>
+</div>
+<div class="section" id="llvm-va-copy-intrinsic">
+<span id="int-va-copy"></span><h4><a class="toc-backref" href="#id1030">‘<tt class="docutils literal"><span class="pre">llvm.va_copy</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-va-copy-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id292">
+<h5><a class="toc-backref" href="#id1031">Syntax:</a><a class="headerlink" href="#id292" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id293">
+<h5><a class="toc-backref" href="#id1032">Overview:</a><a class="headerlink" href="#id293" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.va_copy</span></tt>‘ intrinsic copies the current argument position
+from the source argument list to the destination argument list.</p>
+</div>
+<div class="section" id="id294">
+<h5><a class="toc-backref" href="#id1033">Arguments:</a><a class="headerlink" href="#id294" title="Permalink to this headline">¶</a></h5>
+<p>The first argument is a pointer to a <tt class="docutils literal"><span class="pre">va_list</span></tt> element to initialize.
+The second argument is a pointer to a <tt class="docutils literal"><span class="pre">va_list</span></tt> element to copy from.</p>
+</div>
+<div class="section" id="id295">
+<h5><a class="toc-backref" href="#id1034">Semantics:</a><a class="headerlink" href="#id295" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.va_copy</span></tt>‘ intrinsic works just like the <tt class="docutils literal"><span class="pre">va_copy</span></tt> macro
+available in C. In a target-dependent way, it copies the source
+<tt class="docutils literal"><span class="pre">va_list</span></tt> element into the destination <tt class="docutils literal"><span class="pre">va_list</span></tt> element. This
+intrinsic is necessary because the `` llvm.va_start`` intrinsic may be
+arbitrarily complex and require, for example, memory allocation.</p>
+</div>
+</div>
+</div>
+<div class="section" id="accurate-garbage-collection-intrinsics">
+<h3><a class="toc-backref" href="#id1035">Accurate Garbage Collection Intrinsics</a><a class="headerlink" href="#accurate-garbage-collection-intrinsics" title="Permalink to this headline">¶</a></h3>
+<p>LLVM support for <a class="reference external" href="GarbageCollection.html">Accurate Garbage Collection</a>
+(GC) requires the implementation and generation of these intrinsics.
+These intrinsics allow identification of <a class="reference internal" href="#int-gcroot"><em>GC roots on the
+stack</em></a>, as well as garbage collector implementations that
+require <a class="reference internal" href="#int-gcread"><em>read</em></a> and <a class="reference internal" href="#int-gcwrite"><em>write</em></a> barriers.
+Front-ends for type-safe garbage collected languages should generate
+these intrinsics to make use of the LLVM garbage collectors. For more
+details, see <a class="reference external" href="GarbageCollection.html">Accurate Garbage Collection with
+LLVM</a>.</p>
+<p>The garbage collection intrinsics only operate on objects in the generic
+address space (address space zero).</p>
+<div class="section" id="llvm-gcroot-intrinsic">
+<span id="int-gcroot"></span><h4><a class="toc-backref" href="#id1036">‘<tt class="docutils literal"><span class="pre">llvm.gcroot</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-gcroot-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id296">
+<h5><a class="toc-backref" href="#id1037">Syntax:</a><a class="headerlink" href="#id296" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id297">
+<h5><a class="toc-backref" href="#id1038">Overview:</a><a class="headerlink" href="#id297" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.gcroot</span></tt>‘ intrinsic declares the existence of a GC root to
+the code generator, and allows some metadata to be associated with it.</p>
+</div>
+<div class="section" id="id298">
+<h5><a class="toc-backref" href="#id1039">Arguments:</a><a class="headerlink" href="#id298" title="Permalink to this headline">¶</a></h5>
+<p>The first argument specifies the address of a stack object that contains
+the root pointer. The second pointer (which must be either a constant or
+a global value address) contains the meta-data to be associated with the
+root.</p>
+</div>
+<div class="section" id="id299">
+<h5><a class="toc-backref" href="#id1040">Semantics:</a><a class="headerlink" href="#id299" title="Permalink to this headline">¶</a></h5>
+<p>At runtime, a call to this intrinsic stores a null pointer into the
+“ptrloc” location. At compile-time, the code generator generates
+information to allow the runtime to find the pointer at GC safe points.
+The ‘<tt class="docutils literal"><span class="pre">llvm.gcroot</span></tt>‘ intrinsic may only be used in a function which
+<a class="reference internal" href="#gc"><em>specifies a GC algorithm</em></a>.</p>
+</div>
+</div>
+<div class="section" id="llvm-gcread-intrinsic">
+<span id="int-gcread"></span><h4><a class="toc-backref" href="#id1041">‘<tt class="docutils literal"><span class="pre">llvm.gcread</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-gcread-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id300">
+<h5><a class="toc-backref" href="#id1042">Syntax:</a><a class="headerlink" href="#id300" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id301">
+<h5><a class="toc-backref" href="#id1043">Overview:</a><a class="headerlink" href="#id301" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.gcread</span></tt>‘ intrinsic identifies reads of references from heap
+locations, allowing garbage collector implementations that require read
+barriers.</p>
+</div>
+<div class="section" id="id302">
+<h5><a class="toc-backref" href="#id1044">Arguments:</a><a class="headerlink" href="#id302" title="Permalink to this headline">¶</a></h5>
+<p>The second argument is the address to read from, which should be an
+address allocated from the garbage collector. The first object is a
+pointer to the start of the referenced object, if needed by the language
+runtime (otherwise null).</p>
+</div>
+<div class="section" id="id303">
+<h5><a class="toc-backref" href="#id1045">Semantics:</a><a class="headerlink" href="#id303" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.gcread</span></tt>‘ intrinsic has the same semantics as a load
+instruction, but may be replaced with substantially more complex code by
+the garbage collector runtime, as needed. The ‘<tt class="docutils literal"><span class="pre">llvm.gcread</span></tt>‘
+intrinsic may only be used in a function which <a class="reference internal" href="#gc"><em>specifies a GC
+algorithm</em></a>.</p>
+</div>
+</div>
+<div class="section" id="llvm-gcwrite-intrinsic">
+<span id="int-gcwrite"></span><h4><a class="toc-backref" href="#id1046">‘<tt class="docutils literal"><span class="pre">llvm.gcwrite</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-gcwrite-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id304">
+<h5><a class="toc-backref" href="#id1047">Syntax:</a><a class="headerlink" href="#id304" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id305">
+<h5><a class="toc-backref" href="#id1048">Overview:</a><a class="headerlink" href="#id305" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.gcwrite</span></tt>‘ intrinsic identifies writes of references to heap
+locations, allowing garbage collector implementations that require write
+barriers (such as generational or reference counting collectors).</p>
+</div>
+<div class="section" id="id306">
+<h5><a class="toc-backref" href="#id1049">Arguments:</a><a class="headerlink" href="#id306" title="Permalink to this headline">¶</a></h5>
+<p>The first argument is the reference to store, the second is the start of
+the object to store it to, and the third is the address of the field of
+Obj to store to. If the runtime does not require a pointer to the
+object, Obj may be null.</p>
+</div>
+<div class="section" id="id307">
+<h5><a class="toc-backref" href="#id1050">Semantics:</a><a class="headerlink" href="#id307" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.gcwrite</span></tt>‘ intrinsic has the same semantics as a store
+instruction, but may be replaced with substantially more complex code by
+the garbage collector runtime, as needed. The ‘<tt class="docutils literal"><span class="pre">llvm.gcwrite</span></tt>‘
+intrinsic may only be used in a function which <a class="reference internal" href="#gc"><em>specifies a GC
+algorithm</em></a>.</p>
+</div>
+</div>
+</div>
+<div class="section" id="code-generator-intrinsics">
+<h3><a class="toc-backref" href="#id1051">Code Generator Intrinsics</a><a class="headerlink" href="#code-generator-intrinsics" title="Permalink to this headline">¶</a></h3>
+<p>These intrinsics are provided by LLVM to expose special features that
+may only be implemented with code generator support.</p>
+<div class="section" id="llvm-returnaddress-intrinsic">
+<h4><a class="toc-backref" href="#id1052">‘<tt class="docutils literal"><span class="pre">llvm.returnaddress</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-returnaddress-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id308">
+<h5><a class="toc-backref" href="#id1053">Syntax:</a><a class="headerlink" href="#id308" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare i8  *@llvm.returnaddress(i32 <level>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id309">
+<h5><a class="toc-backref" href="#id1054">Overview:</a><a class="headerlink" href="#id309" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.returnaddress</span></tt>‘ intrinsic attempts to compute a
+target-specific value indicating the return address of the current
+function or one of its callers.</p>
+</div>
+<div class="section" id="id310">
+<h5><a class="toc-backref" href="#id1055">Arguments:</a><a class="headerlink" href="#id310" title="Permalink to this headline">¶</a></h5>
+<p>The argument to this intrinsic indicates which function to return the
+address for. Zero indicates the calling function, one indicates its
+caller, etc. The argument is <strong>required</strong> to be a constant integer
+value.</p>
+</div>
+<div class="section" id="id311">
+<h5><a class="toc-backref" href="#id1056">Semantics:</a><a class="headerlink" href="#id311" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.returnaddress</span></tt>‘ intrinsic either returns a pointer
+indicating the return address of the specified call frame, or zero if it
+cannot be identified. The value returned by this intrinsic is likely to
+be incorrect or 0 for arguments other than zero, so it should only be
+used for debugging purposes.</p>
+<p>Note that calling this intrinsic does not prevent function inlining or
+other aggressive transformations, so the value returned may not be that
+of the obvious source-language caller.</p>
+</div>
+</div>
+<div class="section" id="llvm-frameaddress-intrinsic">
+<h4><a class="toc-backref" href="#id1057">‘<tt class="docutils literal"><span class="pre">llvm.frameaddress</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-frameaddress-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id312">
+<h5><a class="toc-backref" href="#id1058">Syntax:</a><a class="headerlink" href="#id312" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare i8* @llvm.frameaddress(i32 <level>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id313">
+<h5><a class="toc-backref" href="#id1059">Overview:</a><a class="headerlink" href="#id313" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.frameaddress</span></tt>‘ intrinsic attempts to return the
+target-specific frame pointer value for the specified stack frame.</p>
+</div>
+<div class="section" id="id314">
+<h5><a class="toc-backref" href="#id1060">Arguments:</a><a class="headerlink" href="#id314" title="Permalink to this headline">¶</a></h5>
+<p>The argument to this intrinsic indicates which function to return the
+frame pointer for. Zero indicates the calling function, one indicates
+its caller, etc. The argument is <strong>required</strong> to be a constant integer
+value.</p>
+</div>
+<div class="section" id="id315">
+<h5><a class="toc-backref" href="#id1061">Semantics:</a><a class="headerlink" href="#id315" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.frameaddress</span></tt>‘ intrinsic either returns a pointer
+indicating the frame address of the specified call frame, or zero if it
+cannot be identified. The value returned by this intrinsic is likely to
+be incorrect or 0 for arguments other than zero, so it should only be
+used for debugging purposes.</p>
+<p>Note that calling this intrinsic does not prevent function inlining or
+other aggressive transformations, so the value returned may not be that
+of the obvious source-language caller.</p>
+</div>
+</div>
+<div class="section" id="llvm-frameallocate-and-llvm-framerecover-intrinsics">
+<h4><a class="toc-backref" href="#id1062">‘<tt class="docutils literal"><span class="pre">llvm.frameallocate</span></tt>‘ and ‘<tt class="docutils literal"><span class="pre">llvm.framerecover</span></tt>‘ Intrinsics</a><a class="headerlink" href="#llvm-frameallocate-and-llvm-framerecover-intrinsics" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id316">
+<h5><a class="toc-backref" href="#id1063">Syntax:</a><a class="headerlink" href="#id316" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare i8* @llvm.frameallocate(i32 %size)
+declare i8* @llvm.framerecover(i8* %func, i8* %fp)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id317">
+<h5><a class="toc-backref" href="#id1064">Overview:</a><a class="headerlink" href="#id317" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.frameallocate</span></tt>‘ intrinsic allocates stack memory at some fixed
+offset from the frame pointer, and the ‘<tt class="docutils literal"><span class="pre">llvm.framerecover</span></tt>‘
+intrinsic applies that offset to a live frame pointer to recover the address of
+the allocation. The offset is computed during frame layout of the caller of
+<tt class="docutils literal"><span class="pre">llvm.frameallocate</span></tt>.</p>
+</div>
+<div class="section" id="id318">
+<h5><a class="toc-backref" href="#id1065">Arguments:</a><a class="headerlink" href="#id318" title="Permalink to this headline">¶</a></h5>
+<p>The <tt class="docutils literal"><span class="pre">size</span></tt> argument to ‘<tt class="docutils literal"><span class="pre">llvm.frameallocate</span></tt>‘ must be a constant integer
+indicating the amount of stack memory to allocate. As with allocas, allocating
+zero bytes is legal, but the result is undefined.</p>
+<p>The <tt class="docutils literal"><span class="pre">func</span></tt> argument to ‘<tt class="docutils literal"><span class="pre">llvm.framerecover</span></tt>‘ must be a constant
+bitcasted pointer to a function defined in the current module. The code
+generator cannot determine the frame allocation offset of functions defined in
+other modules.</p>
+<p>The <tt class="docutils literal"><span class="pre">fp</span></tt> argument to ‘<tt class="docutils literal"><span class="pre">llvm.framerecover</span></tt>‘ must be a frame
+pointer of a call frame that is currently live. The return value of
+‘<tt class="docutils literal"><span class="pre">llvm.frameaddress</span></tt>‘ is one way to produce such a value, but most platforms
+also expose the frame pointer through stack unwinding mechanisms.</p>
+</div>
+<div class="section" id="id319">
+<h5><a class="toc-backref" href="#id1066">Semantics:</a><a class="headerlink" href="#id319" title="Permalink to this headline">¶</a></h5>
+<p>These intrinsics allow a group of functions to access one stack memory
+allocation in an ancestor stack frame. The memory returned from
+‘<tt class="docutils literal"><span class="pre">llvm.frameallocate</span></tt>‘ may be allocated prior to stack realignment, so the
+memory is only aligned to the ABI-required stack alignment.  Each function may
+only call ‘<tt class="docutils literal"><span class="pre">llvm.frameallocate</span></tt>‘ one or zero times from the function entry
+block.  The frame allocation intrinsic inhibits inlining, as any frame
+allocations in the inlined function frame are likely to be at a different
+offset from the one used by ‘<tt class="docutils literal"><span class="pre">llvm.framerecover</span></tt>‘ called with the
+uninlined function.</p>
+</div>
+</div>
+<div class="section" id="llvm-read-register-and-llvm-write-register-intrinsics">
+<span id="int-write-register"></span><span id="int-read-register"></span><h4><a class="toc-backref" href="#id1067">‘<tt class="docutils literal"><span class="pre">llvm.read_register</span></tt>‘ and ‘<tt class="docutils literal"><span class="pre">llvm.write_register</span></tt>‘ Intrinsics</a><a class="headerlink" href="#llvm-read-register-and-llvm-write-register-intrinsics" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id320">
+<h5><a class="toc-backref" href="#id1068">Syntax:</a><a class="headerlink" href="#id320" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare i32 @llvm.read_register.i32(metadata)
+declare i64 @llvm.read_register.i64(metadata)
+declare void @llvm.write_register.i32(metadata, i32 @value)
+declare void @llvm.write_register.i64(metadata, i64 @value)
+!0 = !{!"sp\00"}
+</pre></div>
+</div>
+</div>
+<div class="section" id="id321">
+<h5><a class="toc-backref" href="#id1069">Overview:</a><a class="headerlink" href="#id321" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.read_register</span></tt>‘ and ‘<tt class="docutils literal"><span class="pre">llvm.write_register</span></tt>‘ intrinsics
+provides access to the named register. The register must be valid on
+the architecture being compiled to. The type needs to be compatible
+with the register being read.</p>
+</div>
+<div class="section" id="id322">
+<h5><a class="toc-backref" href="#id1070">Semantics:</a><a class="headerlink" href="#id322" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.read_register</span></tt>‘ intrinsic returns the current value of the
+register, where possible. The ‘<tt class="docutils literal"><span class="pre">llvm.write_register</span></tt>‘ intrinsic sets
+the current value of the register, where possible.</p>
+<p>This is useful to implement named register global variables that need
+to always be mapped to a specific register, as is common practice on
+bare-metal programs including OS kernels.</p>
+<p>The compiler doesn’t check for register availability or use of the used
+register in surrounding code, including inline assembly. Because of that,
+allocatable registers are not supported.</p>
+<p>Warning: So far it only works with the stack pointer on selected
+architectures (ARM, AArch64, PowerPC and x86_64). Significant amount of
+work is needed to support other registers and even more so, allocatable
+registers.</p>
+</div>
+</div>
+<div class="section" id="llvm-stacksave-intrinsic">
+<span id="int-stacksave"></span><h4><a class="toc-backref" href="#id1071">‘<tt class="docutils literal"><span class="pre">llvm.stacksave</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-stacksave-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id323">
+<h5><a class="toc-backref" href="#id1072">Syntax:</a><a class="headerlink" href="#id323" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare i8* @llvm.stacksave()
+</pre></div>
+</div>
+</div>
+<div class="section" id="id324">
+<h5><a class="toc-backref" href="#id1073">Overview:</a><a class="headerlink" href="#id324" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.stacksave</span></tt>‘ intrinsic is used to remember the current state
+of the function stack, for use with
+<a class="reference internal" href="#int-stackrestore"><em>llvm.stackrestore</em></a>. This is useful for
+implementing language features like scoped automatic variable sized
+arrays in C99.</p>
+</div>
+<div class="section" id="id325">
+<h5><a class="toc-backref" href="#id1074">Semantics:</a><a class="headerlink" href="#id325" title="Permalink to this headline">¶</a></h5>
+<p>This intrinsic returns a opaque pointer value that can be passed to
+<a class="reference internal" href="#int-stackrestore"><em>llvm.stackrestore</em></a>. When an
+<tt class="docutils literal"><span class="pre">llvm.stackrestore</span></tt> intrinsic is executed with a value saved from
+<tt class="docutils literal"><span class="pre">llvm.stacksave</span></tt>, it effectively restores the state of the stack to
+the state it was in when the <tt class="docutils literal"><span class="pre">llvm.stacksave</span></tt> intrinsic executed. In
+practice, this pops any <a class="reference internal" href="#i-alloca"><em>alloca</em></a> blocks from the stack that
+were allocated after the <tt class="docutils literal"><span class="pre">llvm.stacksave</span></tt> was executed.</p>
+</div>
+</div>
+<div class="section" id="llvm-stackrestore-intrinsic">
+<span id="int-stackrestore"></span><h4><a class="toc-backref" href="#id1075">‘<tt class="docutils literal"><span class="pre">llvm.stackrestore</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-stackrestore-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id326">
+<h5><a class="toc-backref" href="#id1076">Syntax:</a><a class="headerlink" href="#id326" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.stackrestore(i8* %ptr)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id327">
+<h5><a class="toc-backref" href="#id1077">Overview:</a><a class="headerlink" href="#id327" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.stackrestore</span></tt>‘ intrinsic is used to restore the state of
+the function stack to the state it was in when the corresponding
+<a class="reference internal" href="#int-stacksave"><em>llvm.stacksave</em></a> intrinsic executed. This is
+useful for implementing language features like scoped automatic variable
+sized arrays in C99.</p>
+</div>
+<div class="section" id="id328">
+<h5><a class="toc-backref" href="#id1078">Semantics:</a><a class="headerlink" href="#id328" title="Permalink to this headline">¶</a></h5>
+<p>See the description for <a class="reference internal" href="#int-stacksave"><em>llvm.stacksave</em></a>.</p>
+</div>
+</div>
+<div class="section" id="llvm-prefetch-intrinsic">
+<h4><a class="toc-backref" href="#id1079">‘<tt class="docutils literal"><span class="pre">llvm.prefetch</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-prefetch-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id329">
+<h5><a class="toc-backref" href="#id1080">Syntax:</a><a class="headerlink" href="#id329" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>, i32 <cache type>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id330">
+<h5><a class="toc-backref" href="#id1081">Overview:</a><a class="headerlink" href="#id330" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.prefetch</span></tt>‘ intrinsic is a hint to the code generator to
+insert a prefetch instruction if supported; otherwise, it is a noop.
+Prefetches have no effect on the behavior of the program but can change
+its performance characteristics.</p>
+</div>
+<div class="section" id="id331">
+<h5><a class="toc-backref" href="#id1082">Arguments:</a><a class="headerlink" href="#id331" title="Permalink to this headline">¶</a></h5>
+<p><tt class="docutils literal"><span class="pre">address</span></tt> is the address to be prefetched, <tt class="docutils literal"><span class="pre">rw</span></tt> is the specifier
+determining if the fetch should be for a read (0) or write (1), and
+<tt class="docutils literal"><span class="pre">locality</span></tt> is a temporal locality specifier ranging from (0) - no
+locality, to (3) - extremely local keep in cache. The <tt class="docutils literal"><span class="pre">cache</span> <span class="pre">type</span></tt>
+specifies whether the prefetch is performed on the data (1) or
+instruction (0) cache. The <tt class="docutils literal"><span class="pre">rw</span></tt>, <tt class="docutils literal"><span class="pre">locality</span></tt> and <tt class="docutils literal"><span class="pre">cache</span> <span class="pre">type</span></tt>
+arguments must be constant integers.</p>
+</div>
+<div class="section" id="id332">
+<h5><a class="toc-backref" href="#id1083">Semantics:</a><a class="headerlink" href="#id332" title="Permalink to this headline">¶</a></h5>
+<p>This intrinsic does not modify the behavior of the program. In
+particular, prefetches cannot trap and do not produce a value. On
+targets that support this intrinsic, the prefetch can provide hints to
+the processor cache for better performance.</p>
+</div>
+</div>
+<div class="section" id="llvm-pcmarker-intrinsic">
+<h4><a class="toc-backref" href="#id1084">‘<tt class="docutils literal"><span class="pre">llvm.pcmarker</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-pcmarker-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id333">
+<h5><a class="toc-backref" href="#id1085">Syntax:</a><a class="headerlink" href="#id333" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.pcmarker(i32 <id>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id334">
+<h5><a class="toc-backref" href="#id1086">Overview:</a><a class="headerlink" href="#id334" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.pcmarker</span></tt>‘ intrinsic is a method to export a Program
+Counter (PC) in a region of code to simulators and other tools. The
+method is target specific, but it is expected that the marker will use
+exported symbols to transmit the PC of the marker. The marker makes no
+guarantees that it will remain with any specific instruction after
+optimizations. It is possible that the presence of a marker will inhibit
+optimizations. The intended use is to be inserted after optimizations to
+allow correlations of simulation runs.</p>
+</div>
+<div class="section" id="id335">
+<h5><a class="toc-backref" href="#id1087">Arguments:</a><a class="headerlink" href="#id335" title="Permalink to this headline">¶</a></h5>
+<p><tt class="docutils literal"><span class="pre">id</span></tt> is a numerical id identifying the marker.</p>
+</div>
+<div class="section" id="id336">
+<h5><a class="toc-backref" href="#id1088">Semantics:</a><a class="headerlink" href="#id336" title="Permalink to this headline">¶</a></h5>
+<p>This intrinsic does not modify the behavior of the program. Backends
+that do not support this intrinsic may ignore it.</p>
+</div>
+</div>
+<div class="section" id="llvm-readcyclecounter-intrinsic">
+<h4><a class="toc-backref" href="#id1089">‘<tt class="docutils literal"><span class="pre">llvm.readcyclecounter</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-readcyclecounter-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id337">
+<h5><a class="toc-backref" href="#id1090">Syntax:</a><a class="headerlink" href="#id337" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare i64 @llvm.readcyclecounter()
+</pre></div>
+</div>
+</div>
+<div class="section" id="id338">
+<h5><a class="toc-backref" href="#id1091">Overview:</a><a class="headerlink" href="#id338" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.readcyclecounter</span></tt>‘ intrinsic provides access to the cycle
+counter register (or similar low latency, high accuracy clocks) on those
+targets that support it. On X86, it should map to RDTSC. On Alpha, it
+should map to RPCC. As the backing counters overflow quickly (on the
+order of 9 seconds on alpha), this should only be used for small
+timings.</p>
+</div>
+<div class="section" id="id339">
+<h5><a class="toc-backref" href="#id1092">Semantics:</a><a class="headerlink" href="#id339" title="Permalink to this headline">¶</a></h5>
+<p>When directly supported, reading the cycle counter should not modify any
+memory. Implementations are allowed to either return a application
+specific value or a system wide value. On backends without support, this
+is lowered to a constant 0.</p>
+<p>Note that runtime support may be conditional on the privilege-level code is
+running at and the host platform.</p>
+</div>
+</div>
+<div class="section" id="llvm-clear-cache-intrinsic">
+<h4><a class="toc-backref" href="#id1093">‘<tt class="docutils literal"><span class="pre">llvm.clear_cache</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-clear-cache-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id340">
+<h5><a class="toc-backref" href="#id1094">Syntax:</a><a class="headerlink" href="#id340" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.clear_cache(i8*, i8*)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id341">
+<h5><a class="toc-backref" href="#id1095">Overview:</a><a class="headerlink" href="#id341" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.clear_cache</span></tt>‘ intrinsic ensures visibility of modifications
+in the specified range to the execution unit of the processor. On
+targets with non-unified instruction and data cache, the implementation
+flushes the instruction cache.</p>
+</div>
+<div class="section" id="id342">
+<h5><a class="toc-backref" href="#id1096">Semantics:</a><a class="headerlink" href="#id342" title="Permalink to this headline">¶</a></h5>
+<p>On platforms with coherent instruction and data caches (e.g. x86), this
+intrinsic is a nop. On platforms with non-coherent instruction and data
+cache (e.g. ARM, MIPS), the intrinsic is lowered either to appropriate
+instructions or a system call, if cache flushing requires special
+privileges.</p>
+<p>The default behavior is to emit a call to <tt class="docutils literal"><span class="pre">__clear_cache</span></tt> from the run
+time library.</p>
+<p>This instrinsic does <em>not</em> empty the instruction pipeline. Modifications
+of the current function are outside the scope of the intrinsic.</p>
+</div>
+</div>
+<div class="section" id="llvm-instrprof-increment-intrinsic">
+<h4><a class="toc-backref" href="#id1097">‘<tt class="docutils literal"><span class="pre">llvm.instrprof_increment</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-instrprof-increment-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id343">
+<h5><a class="toc-backref" href="#id1098">Syntax:</a><a class="headerlink" href="#id343" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.instrprof_increment(i8* <name>, i64 <hash>,
+                                       i32 <num-counters>, i32 <index>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id344">
+<h5><a class="toc-backref" href="#id1099">Overview:</a><a class="headerlink" href="#id344" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.instrprof_increment</span></tt>‘ intrinsic can be emitted by a
+frontend for use with instrumentation based profiling. These will be
+lowered by the <tt class="docutils literal"><span class="pre">-instrprof</span></tt> pass to generate execution counts of a
+program at runtime.</p>
+</div>
+<div class="section" id="id345">
+<h5><a class="toc-backref" href="#id1100">Arguments:</a><a class="headerlink" href="#id345" title="Permalink to this headline">¶</a></h5>
+<p>The first argument is a pointer to a global variable containing the
+name of the entity being instrumented. This should generally be the
+(mangled) function name for a set of counters.</p>
+<p>The second argument is a hash value that can be used by the consumer
+of the profile data to detect changes to the instrumented source, and
+the third is the number of counters associated with <tt class="docutils literal"><span class="pre">name</span></tt>. It is an
+error if <tt class="docutils literal"><span class="pre">hash</span></tt> or <tt class="docutils literal"><span class="pre">num-counters</span></tt> differ between two instances of
+<tt class="docutils literal"><span class="pre">instrprof_increment</span></tt> that refer to the same name.</p>
+<p>The last argument refers to which of the counters for <tt class="docutils literal"><span class="pre">name</span></tt> should
+be incremented. It should be a value between 0 and <tt class="docutils literal"><span class="pre">num-counters</span></tt>.</p>
+</div>
+<div class="section" id="id346">
+<h5><a class="toc-backref" href="#id1101">Semantics:</a><a class="headerlink" href="#id346" title="Permalink to this headline">¶</a></h5>
+<p>This intrinsic represents an increment of a profiling counter. It will
+cause the <tt class="docutils literal"><span class="pre">-instrprof</span></tt> pass to generate the appropriate data
+structures and the code to increment the appropriate value, in a
+format that can be written out by a compiler runtime and consumed via
+the <tt class="docutils literal"><span class="pre">llvm-profdata</span></tt> tool.</p>
+</div>
+</div>
+</div>
+<div class="section" id="standard-c-library-intrinsics">
+<h3><a class="toc-backref" href="#id1102">Standard C Library Intrinsics</a><a class="headerlink" href="#standard-c-library-intrinsics" title="Permalink to this headline">¶</a></h3>
+<p>LLVM provides intrinsics for a few important standard C library
+functions. These intrinsics allow source-language front-ends to pass
+information about the alignment of the pointer arguments to the code
+generator, providing opportunity for more efficient code generation.</p>
+<div class="section" id="llvm-memcpy-intrinsic">
+<span id="int-memcpy"></span><h4><a class="toc-backref" href="#id1103">‘<tt class="docutils literal"><span class="pre">llvm.memcpy</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-memcpy-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id347">
+<h5><a class="toc-backref" href="#id1104">Syntax:</a><a class="headerlink" href="#id347" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.memcpy</span></tt> on any
+integer bit width and for different address spaces. Not all targets
+support all bit widths however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.memcpy.p0i8.p0i8.i32(i8* <dest>, i8* <src>,
+                                        i32 <len>, i32 <align>, i1 <isvolatile>)
+declare void @llvm.memcpy.p0i8.p0i8.i64(i8* <dest>, i8* <src>,
+                                        i64 <len>, i32 <align>, i1 <isvolatile>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id348">
+<h5><a class="toc-backref" href="#id1105">Overview:</a><a class="headerlink" href="#id348" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.memcpy.*</span></tt>‘ intrinsics copy a block of memory from the
+source location to the destination location.</p>
+<p>Note that, unlike the standard libc function, the <tt class="docutils literal"><span class="pre">llvm.memcpy.*</span></tt>
+intrinsics do not return a value, takes extra alignment/isvolatile
+arguments and the pointers can be in specified address spaces.</p>
+</div>
+<div class="section" id="id349">
+<h5><a class="toc-backref" href="#id1106">Arguments:</a><a class="headerlink" href="#id349" title="Permalink to this headline">¶</a></h5>
+<p>The first argument is a pointer to the destination, the second is a
+pointer to the source. The third argument is an integer argument
+specifying the number of bytes to copy, the fourth argument is the
+alignment of the source and destination locations, and the fifth is a
+boolean indicating a volatile access.</p>
+<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
+then the caller guarantees that both the source and destination pointers
+are aligned to that boundary.</p>
+<p>If the <tt class="docutils literal"><span class="pre">isvolatile</span></tt> parameter is <tt class="docutils literal"><span class="pre">true</span></tt>, the <tt class="docutils literal"><span class="pre">llvm.memcpy</span></tt> call is
+a <a class="reference internal" href="#volatile"><em>volatile operation</em></a>. The detailed access behavior is not
+very cleanly specified and it is unwise to depend on it.</p>
+</div>
+<div class="section" id="id350">
+<h5><a class="toc-backref" href="#id1107">Semantics:</a><a class="headerlink" href="#id350" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.memcpy.*</span></tt>‘ intrinsics copy a block of memory from the
+source location to the destination location, which are not allowed to
+overlap. It copies “len” bytes of memory over. If the argument is known
+to be aligned to some boundary, this can be specified as the fourth
+argument, otherwise it should be set to 0 or 1 (both meaning no alignment).</p>
+</div>
+</div>
+<div class="section" id="llvm-memmove-intrinsic">
+<h4><a class="toc-backref" href="#id1108">‘<tt class="docutils literal"><span class="pre">llvm.memmove</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-memmove-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id351">
+<h5><a class="toc-backref" href="#id1109">Syntax:</a><a class="headerlink" href="#id351" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer
+bit width and for different address space. Not all targets support all
+bit widths however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.memmove.p0i8.p0i8.i32(i8* <dest>, i8* <src>,
+                                         i32 <len>, i32 <align>, i1 <isvolatile>)
+declare void @llvm.memmove.p0i8.p0i8.i64(i8* <dest>, i8* <src>,
+                                         i64 <len>, i32 <align>, i1 <isvolatile>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id352">
+<h5><a class="toc-backref" href="#id1110">Overview:</a><a class="headerlink" href="#id352" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.memmove.*</span></tt>‘ intrinsics move a block of memory from the
+source location to the destination location. It is similar to the
+‘<tt class="docutils literal"><span class="pre">llvm.memcpy</span></tt>‘ intrinsic but allows the two memory locations to
+overlap.</p>
+<p>Note that, unlike the standard libc function, the <tt class="docutils literal"><span class="pre">llvm.memmove.*</span></tt>
+intrinsics do not return a value, takes extra alignment/isvolatile
+arguments and the pointers can be in specified address spaces.</p>
+</div>
+<div class="section" id="id353">
+<h5><a class="toc-backref" href="#id1111">Arguments:</a><a class="headerlink" href="#id353" title="Permalink to this headline">¶</a></h5>
+<p>The first argument is a pointer to the destination, the second is a
+pointer to the source. The third argument is an integer argument
+specifying the number of bytes to copy, the fourth argument is the
+alignment of the source and destination locations, and the fifth is a
+boolean indicating a volatile access.</p>
+<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
+then the caller guarantees that the source and destination pointers are
+aligned to that boundary.</p>
+<p>If the <tt class="docutils literal"><span class="pre">isvolatile</span></tt> parameter is <tt class="docutils literal"><span class="pre">true</span></tt>, the <tt class="docutils literal"><span class="pre">llvm.memmove</span></tt> call
+is a <a class="reference internal" href="#volatile"><em>volatile operation</em></a>. The detailed access behavior is
+not very cleanly specified and it is unwise to depend on it.</p>
+</div>
+<div class="section" id="id354">
+<h5><a class="toc-backref" href="#id1112">Semantics:</a><a class="headerlink" href="#id354" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.memmove.*</span></tt>‘ intrinsics copy a block of memory from the
+source location to the destination location, which may overlap. It
+copies “len” bytes of memory over. If the argument is known to be
+aligned to some boundary, this can be specified as the fourth argument,
+otherwise it should be set to 0 or 1 (both meaning no alignment).</p>
+</div>
+</div>
+<div class="section" id="llvm-memset-intrinsics">
+<h4><a class="toc-backref" href="#id1113">‘<tt class="docutils literal"><span class="pre">llvm.memset.*</span></tt>‘ Intrinsics</a><a class="headerlink" href="#llvm-memset-intrinsics" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id355">
+<h5><a class="toc-backref" href="#id1114">Syntax:</a><a class="headerlink" href="#id355" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use llvm.memset on any integer
+bit width and for different address spaces. However, not all targets
+support all bit widths.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.memset.p0i8.i32(i8* <dest>, i8 <val>,
+                                   i32 <len>, i32 <align>, i1 <isvolatile>)
+declare void @llvm.memset.p0i8.i64(i8* <dest>, i8 <val>,
+                                   i64 <len>, i32 <align>, i1 <isvolatile>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id356">
+<h5><a class="toc-backref" href="#id1115">Overview:</a><a class="headerlink" href="#id356" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.memset.*</span></tt>‘ intrinsics fill a block of memory with a
+particular byte value.</p>
+<p>Note that, unlike the standard libc function, the <tt class="docutils literal"><span class="pre">llvm.memset</span></tt>
+intrinsic does not return a value and takes extra alignment/volatile
+arguments. Also, the destination can be in an arbitrary address space.</p>
+</div>
+<div class="section" id="id357">
+<h5><a class="toc-backref" href="#id1116">Arguments:</a><a class="headerlink" href="#id357" title="Permalink to this headline">¶</a></h5>
+<p>The first argument is a pointer to the destination to fill, the second
+is the byte value with which to fill it, the third argument is an
+integer argument specifying the number of bytes to fill, and the fourth
+argument is the known alignment of the destination location.</p>
+<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
+then the caller guarantees that the destination pointer is aligned to
+that boundary.</p>
+<p>If the <tt class="docutils literal"><span class="pre">isvolatile</span></tt> parameter is <tt class="docutils literal"><span class="pre">true</span></tt>, the <tt class="docutils literal"><span class="pre">llvm.memset</span></tt> call is
+a <a class="reference internal" href="#volatile"><em>volatile operation</em></a>. The detailed access behavior is not
+very cleanly specified and it is unwise to depend on it.</p>
+</div>
+<div class="section" id="id358">
+<h5><a class="toc-backref" href="#id1117">Semantics:</a><a class="headerlink" href="#id358" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.memset.*</span></tt>‘ intrinsics fill “len” bytes of memory starting
+at the destination location. If the argument is known to be aligned to
+some boundary, this can be specified as the fourth argument, otherwise
+it should be set to 0 or 1 (both meaning no alignment).</p>
+</div>
+</div>
+<div class="section" id="llvm-sqrt-intrinsic">
+<h4><a class="toc-backref" href="#id1118">‘<tt class="docutils literal"><span class="pre">llvm.sqrt.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-sqrt-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id359">
+<h5><a class="toc-backref" href="#id1119">Syntax:</a><a class="headerlink" href="#id359" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.sqrt</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.sqrt.f32(float %Val)
+declare double    @llvm.sqrt.f64(double %Val)
+declare x86_fp80  @llvm.sqrt.f80(x86_fp80 %Val)
+declare fp128     @llvm.sqrt.f128(fp128 %Val)
+declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id360">
+<h5><a class="toc-backref" href="#id1120">Overview:</a><a class="headerlink" href="#id360" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.sqrt</span></tt>‘ intrinsics return the sqrt of the specified operand,
+returning the same value as the libm ‘<tt class="docutils literal"><span class="pre">sqrt</span></tt>‘ functions would. Unlike
+<tt class="docutils literal"><span class="pre">sqrt</span></tt> in libm, however, <tt class="docutils literal"><span class="pre">llvm.sqrt</span></tt> has undefined behavior for
+negative numbers other than -0.0 (which allows for better optimization,
+because there is no need to worry about errno being set).
+<tt class="docutils literal"><span class="pre">llvm.sqrt(-0.0)</span></tt> is defined to return -0.0 like IEEE sqrt.</p>
+</div>
+<div class="section" id="id361">
+<h5><a class="toc-backref" href="#id1121">Arguments:</a><a class="headerlink" href="#id361" title="Permalink to this headline">¶</a></h5>
+<p>The argument and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id362">
+<h5><a class="toc-backref" href="#id1122">Semantics:</a><a class="headerlink" href="#id362" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the sqrt of the specified operand if it is a
+nonnegative floating point number.</p>
+</div>
+</div>
+<div class="section" id="llvm-powi-intrinsic">
+<h4><a class="toc-backref" href="#id1123">‘<tt class="docutils literal"><span class="pre">llvm.powi.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-powi-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id363">
+<h5><a class="toc-backref" href="#id1124">Syntax:</a><a class="headerlink" href="#id363" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.powi</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.powi.f32(float  %Val, i32 %power)
+declare double    @llvm.powi.f64(double %Val, i32 %power)
+declare x86_fp80  @llvm.powi.f80(x86_fp80  %Val, i32 %power)
+declare fp128     @llvm.powi.f128(fp128 %Val, i32 %power)
+declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128  %Val, i32 %power)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id364">
+<h5><a class="toc-backref" href="#id1125">Overview:</a><a class="headerlink" href="#id364" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.powi.*</span></tt>‘ intrinsics return the first operand raised to the
+specified (positive or negative) power. The order of evaluation of
+multiplications is not defined. When a vector of floating point type is
+used, the second argument remains a scalar integer value.</p>
+</div>
+<div class="section" id="id365">
+<h5><a class="toc-backref" href="#id1126">Arguments:</a><a class="headerlink" href="#id365" title="Permalink to this headline">¶</a></h5>
+<p>The second argument is an integer power, and the first is a value to
+raise to that power.</p>
+</div>
+<div class="section" id="id366">
+<h5><a class="toc-backref" href="#id1127">Semantics:</a><a class="headerlink" href="#id366" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the first value raised to the second power with an
+unspecified sequence of rounding operations.</p>
+</div>
+</div>
+<div class="section" id="llvm-sin-intrinsic">
+<h4><a class="toc-backref" href="#id1128">‘<tt class="docutils literal"><span class="pre">llvm.sin.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-sin-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id367">
+<h5><a class="toc-backref" href="#id1129">Syntax:</a><a class="headerlink" href="#id367" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.sin</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.sin.f32(float  %Val)
+declare double    @llvm.sin.f64(double %Val)
+declare x86_fp80  @llvm.sin.f80(x86_fp80  %Val)
+declare fp128     @llvm.sin.f128(fp128 %Val)
+declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128  %Val)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id368">
+<h5><a class="toc-backref" href="#id1130">Overview:</a><a class="headerlink" href="#id368" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.sin.*</span></tt>‘ intrinsics return the sine of the operand.</p>
+</div>
+<div class="section" id="id369">
+<h5><a class="toc-backref" href="#id1131">Arguments:</a><a class="headerlink" href="#id369" title="Permalink to this headline">¶</a></h5>
+<p>The argument and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id370">
+<h5><a class="toc-backref" href="#id1132">Semantics:</a><a class="headerlink" href="#id370" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the sine of the specified operand, returning the
+same values as the libm <tt class="docutils literal"><span class="pre">sin</span></tt> functions would, and handles error
+conditions in the same way.</p>
+</div>
+</div>
+<div class="section" id="llvm-cos-intrinsic">
+<h4><a class="toc-backref" href="#id1133">‘<tt class="docutils literal"><span class="pre">llvm.cos.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-cos-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id371">
+<h5><a class="toc-backref" href="#id1134">Syntax:</a><a class="headerlink" href="#id371" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.cos</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.cos.f32(float  %Val)
+declare double    @llvm.cos.f64(double %Val)
+declare x86_fp80  @llvm.cos.f80(x86_fp80  %Val)
+declare fp128     @llvm.cos.f128(fp128 %Val)
+declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128  %Val)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id372">
+<h5><a class="toc-backref" href="#id1135">Overview:</a><a class="headerlink" href="#id372" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.cos.*</span></tt>‘ intrinsics return the cosine of the operand.</p>
+</div>
+<div class="section" id="id373">
+<h5><a class="toc-backref" href="#id1136">Arguments:</a><a class="headerlink" href="#id373" title="Permalink to this headline">¶</a></h5>
+<p>The argument and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id374">
+<h5><a class="toc-backref" href="#id1137">Semantics:</a><a class="headerlink" href="#id374" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the cosine of the specified operand, returning the
+same values as the libm <tt class="docutils literal"><span class="pre">cos</span></tt> functions would, and handles error
+conditions in the same way.</p>
+</div>
+</div>
+<div class="section" id="llvm-pow-intrinsic">
+<h4><a class="toc-backref" href="#id1138">‘<tt class="docutils literal"><span class="pre">llvm.pow.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-pow-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id375">
+<h5><a class="toc-backref" href="#id1139">Syntax:</a><a class="headerlink" href="#id375" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.pow</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.pow.f32(float  %Val, float %Power)
+declare double    @llvm.pow.f64(double %Val, double %Power)
+declare x86_fp80  @llvm.pow.f80(x86_fp80  %Val, x86_fp80 %Power)
+declare fp128     @llvm.pow.f128(fp128 %Val, fp128 %Power)
+declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128  %Val, ppc_fp128 Power)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id376">
+<h5><a class="toc-backref" href="#id1140">Overview:</a><a class="headerlink" href="#id376" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.pow.*</span></tt>‘ intrinsics return the first operand raised to the
+specified (positive or negative) power.</p>
+</div>
+<div class="section" id="id377">
+<h5><a class="toc-backref" href="#id1141">Arguments:</a><a class="headerlink" href="#id377" title="Permalink to this headline">¶</a></h5>
+<p>The second argument is a floating point power, and the first is a value
+to raise to that power.</p>
+</div>
+<div class="section" id="id378">
+<h5><a class="toc-backref" href="#id1142">Semantics:</a><a class="headerlink" href="#id378" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the first value raised to the second power,
+returning the same values as the libm <tt class="docutils literal"><span class="pre">pow</span></tt> functions would, and
+handles error conditions in the same way.</p>
+</div>
+</div>
+<div class="section" id="llvm-exp-intrinsic">
+<h4><a class="toc-backref" href="#id1143">‘<tt class="docutils literal"><span class="pre">llvm.exp.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-exp-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id379">
+<h5><a class="toc-backref" href="#id1144">Syntax:</a><a class="headerlink" href="#id379" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.exp</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.exp.f32(float  %Val)
+declare double    @llvm.exp.f64(double %Val)
+declare x86_fp80  @llvm.exp.f80(x86_fp80  %Val)
+declare fp128     @llvm.exp.f128(fp128 %Val)
+declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128  %Val)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id380">
+<h5><a class="toc-backref" href="#id1145">Overview:</a><a class="headerlink" href="#id380" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.exp.*</span></tt>‘ intrinsics perform the exp function.</p>
+</div>
+<div class="section" id="id381">
+<h5><a class="toc-backref" href="#id1146">Arguments:</a><a class="headerlink" href="#id381" title="Permalink to this headline">¶</a></h5>
+<p>The argument and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id382">
+<h5><a class="toc-backref" href="#id1147">Semantics:</a><a class="headerlink" href="#id382" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the same values as the libm <tt class="docutils literal"><span class="pre">exp</span></tt> functions
+would, and handles error conditions in the same way.</p>
+</div>
+</div>
+<div class="section" id="llvm-exp2-intrinsic">
+<h4><a class="toc-backref" href="#id1148">‘<tt class="docutils literal"><span class="pre">llvm.exp2.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-exp2-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id383">
+<h5><a class="toc-backref" href="#id1149">Syntax:</a><a class="headerlink" href="#id383" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.exp2</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.exp2.f32(float  %Val)
+declare double    @llvm.exp2.f64(double %Val)
+declare x86_fp80  @llvm.exp2.f80(x86_fp80  %Val)
+declare fp128     @llvm.exp2.f128(fp128 %Val)
+declare ppc_fp128 @llvm.exp2.ppcf128(ppc_fp128  %Val)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id384">
+<h5><a class="toc-backref" href="#id1150">Overview:</a><a class="headerlink" href="#id384" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.exp2.*</span></tt>‘ intrinsics perform the exp2 function.</p>
+</div>
+<div class="section" id="id385">
+<h5><a class="toc-backref" href="#id1151">Arguments:</a><a class="headerlink" href="#id385" title="Permalink to this headline">¶</a></h5>
+<p>The argument and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id386">
+<h5><a class="toc-backref" href="#id1152">Semantics:</a><a class="headerlink" href="#id386" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the same values as the libm <tt class="docutils literal"><span class="pre">exp2</span></tt> functions
+would, and handles error conditions in the same way.</p>
+</div>
+</div>
+<div class="section" id="llvm-log-intrinsic">
+<h4><a class="toc-backref" href="#id1153">‘<tt class="docutils literal"><span class="pre">llvm.log.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-log-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id387">
+<h5><a class="toc-backref" href="#id1154">Syntax:</a><a class="headerlink" href="#id387" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.log</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.log.f32(float  %Val)
+declare double    @llvm.log.f64(double %Val)
+declare x86_fp80  @llvm.log.f80(x86_fp80  %Val)
+declare fp128     @llvm.log.f128(fp128 %Val)
+declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128  %Val)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id388">
+<h5><a class="toc-backref" href="#id1155">Overview:</a><a class="headerlink" href="#id388" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.log.*</span></tt>‘ intrinsics perform the log function.</p>
+</div>
+<div class="section" id="id389">
+<h5><a class="toc-backref" href="#id1156">Arguments:</a><a class="headerlink" href="#id389" title="Permalink to this headline">¶</a></h5>
+<p>The argument and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id390">
+<h5><a class="toc-backref" href="#id1157">Semantics:</a><a class="headerlink" href="#id390" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the same values as the libm <tt class="docutils literal"><span class="pre">log</span></tt> functions
+would, and handles error conditions in the same way.</p>
+</div>
+</div>
+<div class="section" id="llvm-log10-intrinsic">
+<h4><a class="toc-backref" href="#id1158">‘<tt class="docutils literal"><span class="pre">llvm.log10.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-log10-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id391">
+<h5><a class="toc-backref" href="#id1159">Syntax:</a><a class="headerlink" href="#id391" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.log10</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.log10.f32(float  %Val)
+declare double    @llvm.log10.f64(double %Val)
+declare x86_fp80  @llvm.log10.f80(x86_fp80  %Val)
+declare fp128     @llvm.log10.f128(fp128 %Val)
+declare ppc_fp128 @llvm.log10.ppcf128(ppc_fp128  %Val)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id392">
+<h5><a class="toc-backref" href="#id1160">Overview:</a><a class="headerlink" href="#id392" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.log10.*</span></tt>‘ intrinsics perform the log10 function.</p>
+</div>
+<div class="section" id="id393">
+<h5><a class="toc-backref" href="#id1161">Arguments:</a><a class="headerlink" href="#id393" title="Permalink to this headline">¶</a></h5>
+<p>The argument and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id394">
+<h5><a class="toc-backref" href="#id1162">Semantics:</a><a class="headerlink" href="#id394" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the same values as the libm <tt class="docutils literal"><span class="pre">log10</span></tt> functions
+would, and handles error conditions in the same way.</p>
+</div>
+</div>
+<div class="section" id="llvm-log2-intrinsic">
+<h4><a class="toc-backref" href="#id1163">‘<tt class="docutils literal"><span class="pre">llvm.log2.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-log2-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id395">
+<h5><a class="toc-backref" href="#id1164">Syntax:</a><a class="headerlink" href="#id395" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.log2</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.log2.f32(float  %Val)
+declare double    @llvm.log2.f64(double %Val)
+declare x86_fp80  @llvm.log2.f80(x86_fp80  %Val)
+declare fp128     @llvm.log2.f128(fp128 %Val)
+declare ppc_fp128 @llvm.log2.ppcf128(ppc_fp128  %Val)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id396">
+<h5><a class="toc-backref" href="#id1165">Overview:</a><a class="headerlink" href="#id396" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.log2.*</span></tt>‘ intrinsics perform the log2 function.</p>
+</div>
+<div class="section" id="id397">
+<h5><a class="toc-backref" href="#id1166">Arguments:</a><a class="headerlink" href="#id397" title="Permalink to this headline">¶</a></h5>
+<p>The argument and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id398">
+<h5><a class="toc-backref" href="#id1167">Semantics:</a><a class="headerlink" href="#id398" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the same values as the libm <tt class="docutils literal"><span class="pre">log2</span></tt> functions
+would, and handles error conditions in the same way.</p>
+</div>
+</div>
+<div class="section" id="llvm-fma-intrinsic">
+<h4><a class="toc-backref" href="#id1168">‘<tt class="docutils literal"><span class="pre">llvm.fma.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-fma-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id399">
+<h5><a class="toc-backref" href="#id1169">Syntax:</a><a class="headerlink" href="#id399" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.fma</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.fma.f32(float  %a, float  %b, float  %c)
+declare double    @llvm.fma.f64(double %a, double %b, double %c)
+declare x86_fp80  @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
+declare fp128     @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
+declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id400">
+<h5><a class="toc-backref" href="#id1170">Overview:</a><a class="headerlink" href="#id400" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.fma.*</span></tt>‘ intrinsics perform the fused multiply-add
+operation.</p>
+</div>
+<div class="section" id="id401">
+<h5><a class="toc-backref" href="#id1171">Arguments:</a><a class="headerlink" href="#id401" title="Permalink to this headline">¶</a></h5>
+<p>The argument and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id402">
+<h5><a class="toc-backref" href="#id1172">Semantics:</a><a class="headerlink" href="#id402" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the same values as the libm <tt class="docutils literal"><span class="pre">fma</span></tt> functions
+would, and does not set errno.</p>
+</div>
+</div>
+<div class="section" id="llvm-fabs-intrinsic">
+<h4><a class="toc-backref" href="#id1173">‘<tt class="docutils literal"><span class="pre">llvm.fabs.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-fabs-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id403">
+<h5><a class="toc-backref" href="#id1174">Syntax:</a><a class="headerlink" href="#id403" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.fabs</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.fabs.f32(float  %Val)
+declare double    @llvm.fabs.f64(double %Val)
+declare x86_fp80  @llvm.fabs.f80(x86_fp80 %Val)
+declare fp128     @llvm.fabs.f128(fp128 %Val)
+declare ppc_fp128 @llvm.fabs.ppcf128(ppc_fp128 %Val)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id404">
+<h5><a class="toc-backref" href="#id1175">Overview:</a><a class="headerlink" href="#id404" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.fabs.*</span></tt>‘ intrinsics return the absolute value of the
+operand.</p>
+</div>
+<div class="section" id="id405">
+<h5><a class="toc-backref" href="#id1176">Arguments:</a><a class="headerlink" href="#id405" title="Permalink to this headline">¶</a></h5>
+<p>The argument and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id406">
+<h5><a class="toc-backref" href="#id1177">Semantics:</a><a class="headerlink" href="#id406" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the same values as the libm <tt class="docutils literal"><span class="pre">fabs</span></tt> functions
+would, and handles error conditions in the same way.</p>
+</div>
+</div>
+<div class="section" id="llvm-minnum-intrinsic">
+<h4><a class="toc-backref" href="#id1178">‘<tt class="docutils literal"><span class="pre">llvm.minnum.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-minnum-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id407">
+<h5><a class="toc-backref" href="#id1179">Syntax:</a><a class="headerlink" href="#id407" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.minnum</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.minnum.f32(float %Val0, float %Val1)
+declare double    @llvm.minnum.f64(double %Val0, double %Val1)
+declare x86_fp80  @llvm.minnum.f80(x86_fp80 %Val0, x86_fp80 %Val1)
+declare fp128     @llvm.minnum.f128(fp128 %Val0, fp128 %Val1)
+declare ppc_fp128 @llvm.minnum.ppcf128(ppc_fp128 %Val0, ppc_fp128 %Val1)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id408">
+<h5><a class="toc-backref" href="#id1180">Overview:</a><a class="headerlink" href="#id408" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.minnum.*</span></tt>‘ intrinsics return the minimum of the two
+arguments.</p>
+</div>
+<div class="section" id="id409">
+<h5><a class="toc-backref" href="#id1181">Arguments:</a><a class="headerlink" href="#id409" title="Permalink to this headline">¶</a></h5>
+<p>The arguments and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id410">
+<h5><a class="toc-backref" href="#id1182">Semantics:</a><a class="headerlink" href="#id410" title="Permalink to this headline">¶</a></h5>
+<p>Follows the IEEE-754 semantics for minNum, which also match for libm’s
+fmin.</p>
+<p>If either operand is a NaN, returns the other non-NaN operand. Returns
+NaN only if both operands are NaN. If the operands compare equal,
+returns a value that compares equal to both operands. This means that
+fmin(+/-0.0, +/-0.0) could return either -0.0 or 0.0.</p>
+</div>
+</div>
+<div class="section" id="llvm-maxnum-intrinsic">
+<h4><a class="toc-backref" href="#id1183">‘<tt class="docutils literal"><span class="pre">llvm.maxnum.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-maxnum-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id411">
+<h5><a class="toc-backref" href="#id1184">Syntax:</a><a class="headerlink" href="#id411" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.maxnum</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.maxnum.f32(float  %Val0, float  %Val1l)
+declare double    @llvm.maxnum.f64(double %Val0, double %Val1)
+declare x86_fp80  @llvm.maxnum.f80(x86_fp80  %Val0, x86_fp80  %Val1)
+declare fp128     @llvm.maxnum.f128(fp128 %Val0, fp128 %Val1)
+declare ppc_fp128 @llvm.maxnum.ppcf128(ppc_fp128  %Val0, ppc_fp128  %Val1)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id412">
+<h5><a class="toc-backref" href="#id1185">Overview:</a><a class="headerlink" href="#id412" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.maxnum.*</span></tt>‘ intrinsics return the maximum of the two
+arguments.</p>
+</div>
+<div class="section" id="id413">
+<h5><a class="toc-backref" href="#id1186">Arguments:</a><a class="headerlink" href="#id413" title="Permalink to this headline">¶</a></h5>
+<p>The arguments and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id414">
+<h5><a class="toc-backref" href="#id1187">Semantics:</a><a class="headerlink" href="#id414" title="Permalink to this headline">¶</a></h5>
+<p>Follows the IEEE-754 semantics for maxNum, which also match for libm’s
+fmax.</p>
+<p>If either operand is a NaN, returns the other non-NaN operand. Returns
+NaN only if both operands are NaN. If the operands compare equal,
+returns a value that compares equal to both operands. This means that
+fmax(+/-0.0, +/-0.0) could return either -0.0 or 0.0.</p>
+</div>
+</div>
+<div class="section" id="llvm-copysign-intrinsic">
+<h4><a class="toc-backref" href="#id1188">‘<tt class="docutils literal"><span class="pre">llvm.copysign.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-copysign-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id415">
+<h5><a class="toc-backref" href="#id1189">Syntax:</a><a class="headerlink" href="#id415" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.copysign</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.copysign.f32(float  %Mag, float  %Sgn)
+declare double    @llvm.copysign.f64(double %Mag, double %Sgn)
+declare x86_fp80  @llvm.copysign.f80(x86_fp80  %Mag, x86_fp80  %Sgn)
+declare fp128     @llvm.copysign.f128(fp128 %Mag, fp128 %Sgn)
+declare ppc_fp128 @llvm.copysign.ppcf128(ppc_fp128  %Mag, ppc_fp128  %Sgn)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id416">
+<h5><a class="toc-backref" href="#id1190">Overview:</a><a class="headerlink" href="#id416" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.copysign.*</span></tt>‘ intrinsics return a value with the magnitude of the
+first operand and the sign of the second operand.</p>
+</div>
+<div class="section" id="id417">
+<h5><a class="toc-backref" href="#id1191">Arguments:</a><a class="headerlink" href="#id417" title="Permalink to this headline">¶</a></h5>
+<p>The arguments and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id418">
+<h5><a class="toc-backref" href="#id1192">Semantics:</a><a class="headerlink" href="#id418" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the same values as the libm <tt class="docutils literal"><span class="pre">copysign</span></tt>
+functions would, and handles error conditions in the same way.</p>
+</div>
+</div>
+<div class="section" id="llvm-floor-intrinsic">
+<h4><a class="toc-backref" href="#id1193">‘<tt class="docutils literal"><span class="pre">llvm.floor.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-floor-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id419">
+<h5><a class="toc-backref" href="#id1194">Syntax:</a><a class="headerlink" href="#id419" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.floor</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.floor.f32(float  %Val)
+declare double    @llvm.floor.f64(double %Val)
+declare x86_fp80  @llvm.floor.f80(x86_fp80  %Val)
+declare fp128     @llvm.floor.f128(fp128 %Val)
+declare ppc_fp128 @llvm.floor.ppcf128(ppc_fp128  %Val)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id420">
+<h5><a class="toc-backref" href="#id1195">Overview:</a><a class="headerlink" href="#id420" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.floor.*</span></tt>‘ intrinsics return the floor of the operand.</p>
+</div>
+<div class="section" id="id421">
+<h5><a class="toc-backref" href="#id1196">Arguments:</a><a class="headerlink" href="#id421" title="Permalink to this headline">¶</a></h5>
+<p>The argument and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id422">
+<h5><a class="toc-backref" href="#id1197">Semantics:</a><a class="headerlink" href="#id422" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the same values as the libm <tt class="docutils literal"><span class="pre">floor</span></tt> functions
+would, and handles error conditions in the same way.</p>
+</div>
+</div>
+<div class="section" id="llvm-ceil-intrinsic">
+<h4><a class="toc-backref" href="#id1198">‘<tt class="docutils literal"><span class="pre">llvm.ceil.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-ceil-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id423">
+<h5><a class="toc-backref" href="#id1199">Syntax:</a><a class="headerlink" href="#id423" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.ceil</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.ceil.f32(float  %Val)
+declare double    @llvm.ceil.f64(double %Val)
+declare x86_fp80  @llvm.ceil.f80(x86_fp80  %Val)
+declare fp128     @llvm.ceil.f128(fp128 %Val)
+declare ppc_fp128 @llvm.ceil.ppcf128(ppc_fp128  %Val)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id424">
+<h5><a class="toc-backref" href="#id1200">Overview:</a><a class="headerlink" href="#id424" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.ceil.*</span></tt>‘ intrinsics return the ceiling of the operand.</p>
+</div>
+<div class="section" id="id425">
+<h5><a class="toc-backref" href="#id1201">Arguments:</a><a class="headerlink" href="#id425" title="Permalink to this headline">¶</a></h5>
+<p>The argument and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id426">
+<h5><a class="toc-backref" href="#id1202">Semantics:</a><a class="headerlink" href="#id426" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the same values as the libm <tt class="docutils literal"><span class="pre">ceil</span></tt> functions
+would, and handles error conditions in the same way.</p>
+</div>
+</div>
+<div class="section" id="llvm-trunc-intrinsic">
+<h4><a class="toc-backref" href="#id1203">‘<tt class="docutils literal"><span class="pre">llvm.trunc.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-trunc-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id427">
+<h5><a class="toc-backref" href="#id1204">Syntax:</a><a class="headerlink" href="#id427" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.trunc</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.trunc.f32(float  %Val)
+declare double    @llvm.trunc.f64(double %Val)
+declare x86_fp80  @llvm.trunc.f80(x86_fp80  %Val)
+declare fp128     @llvm.trunc.f128(fp128 %Val)
+declare ppc_fp128 @llvm.trunc.ppcf128(ppc_fp128  %Val)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id428">
+<h5><a class="toc-backref" href="#id1205">Overview:</a><a class="headerlink" href="#id428" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.trunc.*</span></tt>‘ intrinsics returns the operand rounded to the
+nearest integer not larger in magnitude than the operand.</p>
+</div>
+<div class="section" id="id429">
+<h5><a class="toc-backref" href="#id1206">Arguments:</a><a class="headerlink" href="#id429" title="Permalink to this headline">¶</a></h5>
+<p>The argument and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id430">
+<h5><a class="toc-backref" href="#id1207">Semantics:</a><a class="headerlink" href="#id430" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the same values as the libm <tt class="docutils literal"><span class="pre">trunc</span></tt> functions
+would, and handles error conditions in the same way.</p>
+</div>
+</div>
+<div class="section" id="llvm-rint-intrinsic">
+<h4><a class="toc-backref" href="#id1208">‘<tt class="docutils literal"><span class="pre">llvm.rint.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-rint-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id431">
+<h5><a class="toc-backref" href="#id1209">Syntax:</a><a class="headerlink" href="#id431" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.rint</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.rint.f32(float  %Val)
+declare double    @llvm.rint.f64(double %Val)
+declare x86_fp80  @llvm.rint.f80(x86_fp80  %Val)
+declare fp128     @llvm.rint.f128(fp128 %Val)
+declare ppc_fp128 @llvm.rint.ppcf128(ppc_fp128  %Val)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id432">
+<h5><a class="toc-backref" href="#id1210">Overview:</a><a class="headerlink" href="#id432" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.rint.*</span></tt>‘ intrinsics returns the operand rounded to the
+nearest integer. It may raise an inexact floating-point exception if the
+operand isn’t an integer.</p>
+</div>
+<div class="section" id="id433">
+<h5><a class="toc-backref" href="#id1211">Arguments:</a><a class="headerlink" href="#id433" title="Permalink to this headline">¶</a></h5>
+<p>The argument and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id434">
+<h5><a class="toc-backref" href="#id1212">Semantics:</a><a class="headerlink" href="#id434" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the same values as the libm <tt class="docutils literal"><span class="pre">rint</span></tt> functions
+would, and handles error conditions in the same way.</p>
+</div>
+</div>
+<div class="section" id="llvm-nearbyint-intrinsic">
+<h4><a class="toc-backref" href="#id1213">‘<tt class="docutils literal"><span class="pre">llvm.nearbyint.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-nearbyint-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id435">
+<h5><a class="toc-backref" href="#id1214">Syntax:</a><a class="headerlink" href="#id435" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.nearbyint</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.nearbyint.f32(float  %Val)
+declare double    @llvm.nearbyint.f64(double %Val)
+declare x86_fp80  @llvm.nearbyint.f80(x86_fp80  %Val)
+declare fp128     @llvm.nearbyint.f128(fp128 %Val)
+declare ppc_fp128 @llvm.nearbyint.ppcf128(ppc_fp128  %Val)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id436">
+<h5><a class="toc-backref" href="#id1215">Overview:</a><a class="headerlink" href="#id436" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.nearbyint.*</span></tt>‘ intrinsics returns the operand rounded to the
+nearest integer.</p>
+</div>
+<div class="section" id="id437">
+<h5><a class="toc-backref" href="#id1216">Arguments:</a><a class="headerlink" href="#id437" title="Permalink to this headline">¶</a></h5>
+<p>The argument and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id438">
+<h5><a class="toc-backref" href="#id1217">Semantics:</a><a class="headerlink" href="#id438" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the same values as the libm <tt class="docutils literal"><span class="pre">nearbyint</span></tt>
+functions would, and handles error conditions in the same way.</p>
+</div>
+</div>
+<div class="section" id="llvm-round-intrinsic">
+<h4><a class="toc-backref" href="#id1218">‘<tt class="docutils literal"><span class="pre">llvm.round.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-round-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id439">
+<h5><a class="toc-backref" href="#id1219">Syntax:</a><a class="headerlink" href="#id439" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.round</span></tt> on any
+floating point or vector of floating point type. Not all targets support
+all types however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare float     @llvm.round.f32(float  %Val)
+declare double    @llvm.round.f64(double %Val)
+declare x86_fp80  @llvm.round.f80(x86_fp80  %Val)
+declare fp128     @llvm.round.f128(fp128 %Val)
+declare ppc_fp128 @llvm.round.ppcf128(ppc_fp128  %Val)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id440">
+<h5><a class="toc-backref" href="#id1220">Overview:</a><a class="headerlink" href="#id440" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.round.*</span></tt>‘ intrinsics returns the operand rounded to the
+nearest integer.</p>
+</div>
+<div class="section" id="id441">
+<h5><a class="toc-backref" href="#id1221">Arguments:</a><a class="headerlink" href="#id441" title="Permalink to this headline">¶</a></h5>
+<p>The argument and return value are floating point numbers of the same
+type.</p>
+</div>
+<div class="section" id="id442">
+<h5><a class="toc-backref" href="#id1222">Semantics:</a><a class="headerlink" href="#id442" title="Permalink to this headline">¶</a></h5>
+<p>This function returns the same values as the libm <tt class="docutils literal"><span class="pre">round</span></tt>
+functions would, and handles error conditions in the same way.</p>
+</div>
+</div>
+</div>
+<div class="section" id="bit-manipulation-intrinsics">
+<h3><a class="toc-backref" href="#id1223">Bit Manipulation Intrinsics</a><a class="headerlink" href="#bit-manipulation-intrinsics" title="Permalink to this headline">¶</a></h3>
+<p>LLVM provides intrinsics for a few important bit manipulation
+operations. These allow efficient code generation for some algorithms.</p>
+<div class="section" id="llvm-bswap-intrinsics">
+<h4><a class="toc-backref" href="#id1224">‘<tt class="docutils literal"><span class="pre">llvm.bswap.*</span></tt>‘ Intrinsics</a><a class="headerlink" href="#llvm-bswap-intrinsics" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id443">
+<h5><a class="toc-backref" href="#id1225">Syntax:</a><a class="headerlink" href="#id443" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic function. You can use bswap on any
+integer type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
+<div class="highlight-python"><div class="highlight"><pre>declare i16 @llvm.bswap.i16(i16 <id>)
+declare i32 @llvm.bswap.i32(i32 <id>)
+declare i64 @llvm.bswap.i64(i64 <id>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id444">
+<h5><a class="toc-backref" href="#id1226">Overview:</a><a class="headerlink" href="#id444" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.bswap</span></tt>‘ family of intrinsics is used to byte swap integer
+values with an even number of bytes (positive multiple of 16 bits).
+These are useful for performing operations on data that is not in the
+target’s native byte order.</p>
+</div>
+<div class="section" id="id445">
+<h5><a class="toc-backref" href="#id1227">Semantics:</a><a class="headerlink" href="#id445" title="Permalink to this headline">¶</a></h5>
+<p>The <tt class="docutils literal"><span class="pre">llvm.bswap.i16</span></tt> intrinsic returns an i16 value that has the high
+and low byte of the input i16 swapped. Similarly, the <tt class="docutils literal"><span class="pre">llvm.bswap.i32</span></tt>
+intrinsic returns an i32 value that has the four bytes of the input i32
+swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the
+returned i32 will have its bytes in 3, 2, 1, 0 order. The
+<tt class="docutils literal"><span class="pre">llvm.bswap.i48</span></tt>, <tt class="docutils literal"><span class="pre">llvm.bswap.i64</span></tt> and other intrinsics extend this
+concept to additional even-byte lengths (6 bytes, 8 bytes and more,
+respectively).</p>
+</div>
+</div>
+<div class="section" id="llvm-ctpop-intrinsic">
+<h4><a class="toc-backref" href="#id1228">‘<tt class="docutils literal"><span class="pre">llvm.ctpop.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-ctpop-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id446">
+<h5><a class="toc-backref" href="#id1229">Syntax:</a><a class="headerlink" href="#id446" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer
+bit width, or on any vector with integer elements. Not all targets
+support all bit widths or vector types, however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare i8 @llvm.ctpop.i8(i8  <src>)
+declare i16 @llvm.ctpop.i16(i16 <src>)
+declare i32 @llvm.ctpop.i32(i32 <src>)
+declare i64 @llvm.ctpop.i64(i64 <src>)
+declare i256 @llvm.ctpop.i256(i256 <src>)
+declare <2 x i32> @llvm.ctpop.v2i32(<2 x i32> <src>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id447">
+<h5><a class="toc-backref" href="#id1230">Overview:</a><a class="headerlink" href="#id447" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.ctpop</span></tt>‘ family of intrinsics counts the number of bits set
+in a value.</p>
+</div>
+<div class="section" id="id448">
+<h5><a class="toc-backref" href="#id1231">Arguments:</a><a class="headerlink" href="#id448" title="Permalink to this headline">¶</a></h5>
+<p>The only argument is the value to be counted. The argument may be of any
+integer type, or a vector with integer elements. The return type must
+match the argument type.</p>
+</div>
+<div class="section" id="id449">
+<h5><a class="toc-backref" href="#id1232">Semantics:</a><a class="headerlink" href="#id449" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.ctpop</span></tt>‘ intrinsic counts the 1’s in a variable, or within
+each element of a vector.</p>
+</div>
+</div>
+<div class="section" id="llvm-ctlz-intrinsic">
+<h4><a class="toc-backref" href="#id1233">‘<tt class="docutils literal"><span class="pre">llvm.ctlz.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-ctlz-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id450">
+<h5><a class="toc-backref" href="#id1234">Syntax:</a><a class="headerlink" href="#id450" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.ctlz</span></tt> on any
+integer bit width, or any vector whose elements are integers. Not all
+targets support all bit widths or vector types, however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare i8   @llvm.ctlz.i8  (i8   <src>, i1 <is_zero_undef>)
+declare i16  @llvm.ctlz.i16 (i16  <src>, i1 <is_zero_undef>)
+declare i32  @llvm.ctlz.i32 (i32  <src>, i1 <is_zero_undef>)
+declare i64  @llvm.ctlz.i64 (i64  <src>, i1 <is_zero_undef>)
+declare i256 @llvm.ctlz.i256(i256 <src>, i1 <is_zero_undef>)
+declase <2 x i32> @llvm.ctlz.v2i32(<2 x i32> <src>, i1 <is_zero_undef>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id451">
+<h5><a class="toc-backref" href="#id1235">Overview:</a><a class="headerlink" href="#id451" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.ctlz</span></tt>‘ family of intrinsic functions counts the number of
+leading zeros in a variable.</p>
+</div>
+<div class="section" id="id452">
+<h5><a class="toc-backref" href="#id1236">Arguments:</a><a class="headerlink" href="#id452" title="Permalink to this headline">¶</a></h5>
+<p>The first argument is the value to be counted. This argument may be of
+any integer type, or a vector with integer element type. The return
+type must match the first argument type.</p>
+<p>The second argument must be a constant and is a flag to indicate whether
+the intrinsic should ensure that a zero as the first argument produces a
+defined result. Historically some architectures did not provide a
+defined result for zero values as efficiently, and many algorithms are
+now predicated on avoiding zero-value inputs.</p>
+</div>
+<div class="section" id="id453">
+<h5><a class="toc-backref" href="#id1237">Semantics:</a><a class="headerlink" href="#id453" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.ctlz</span></tt>‘ intrinsic counts the leading (most significant)
+zeros in a variable, or within each element of the vector. If
+<tt class="docutils literal"><span class="pre">src</span> <span class="pre">==</span> <span class="pre">0</span></tt> then the result is the size in bits of the type of <tt class="docutils literal"><span class="pre">src</span></tt>
+if <tt class="docutils literal"><span class="pre">is_zero_undef</span> <span class="pre">==</span> <span class="pre">0</span></tt> and <tt class="docutils literal"><span class="pre">undef</span></tt> otherwise. For example,
+<tt class="docutils literal"><span class="pre">llvm.ctlz(i32</span> <span class="pre">2)</span> <span class="pre">=</span> <span class="pre">30</span></tt>.</p>
+</div>
+</div>
+<div class="section" id="llvm-cttz-intrinsic">
+<h4><a class="toc-backref" href="#id1238">‘<tt class="docutils literal"><span class="pre">llvm.cttz.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-cttz-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id454">
+<h5><a class="toc-backref" href="#id1239">Syntax:</a><a class="headerlink" href="#id454" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.cttz</span></tt> on any
+integer bit width, or any vector of integer elements. Not all targets
+support all bit widths or vector types, however.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare i8   @llvm.cttz.i8  (i8   <src>, i1 <is_zero_undef>)
+declare i16  @llvm.cttz.i16 (i16  <src>, i1 <is_zero_undef>)
+declare i32  @llvm.cttz.i32 (i32  <src>, i1 <is_zero_undef>)
+declare i64  @llvm.cttz.i64 (i64  <src>, i1 <is_zero_undef>)
+declare i256 @llvm.cttz.i256(i256 <src>, i1 <is_zero_undef>)
+declase <2 x i32> @llvm.cttz.v2i32(<2 x i32> <src>, i1 <is_zero_undef>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id455">
+<h5><a class="toc-backref" href="#id1240">Overview:</a><a class="headerlink" href="#id455" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.cttz</span></tt>‘ family of intrinsic functions counts the number of
+trailing zeros.</p>
+</div>
+<div class="section" id="id456">
+<h5><a class="toc-backref" href="#id1241">Arguments:</a><a class="headerlink" href="#id456" title="Permalink to this headline">¶</a></h5>
+<p>The first argument is the value to be counted. This argument may be of
+any integer type, or a vector with integer element type. The return
+type must match the first argument type.</p>
+<p>The second argument must be a constant and is a flag to indicate whether
+the intrinsic should ensure that a zero as the first argument produces a
+defined result. Historically some architectures did not provide a
+defined result for zero values as efficiently, and many algorithms are
+now predicated on avoiding zero-value inputs.</p>
+</div>
+<div class="section" id="id457">
+<h5><a class="toc-backref" href="#id1242">Semantics:</a><a class="headerlink" href="#id457" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.cttz</span></tt>‘ intrinsic counts the trailing (least significant)
+zeros in a variable, or within each element of a vector. If <tt class="docutils literal"><span class="pre">src</span> <span class="pre">==</span> <span class="pre">0</span></tt>
+then the result is the size in bits of the type of <tt class="docutils literal"><span class="pre">src</span></tt> if
+<tt class="docutils literal"><span class="pre">is_zero_undef</span> <span class="pre">==</span> <span class="pre">0</span></tt> and <tt class="docutils literal"><span class="pre">undef</span></tt> otherwise. For example,
+<tt class="docutils literal"><span class="pre">llvm.cttz(2)</span> <span class="pre">=</span> <span class="pre">1</span></tt>.</p>
+</div>
+</div>
+</div>
+<div class="section" id="arithmetic-with-overflow-intrinsics">
+<h3><a class="toc-backref" href="#id1243">Arithmetic with Overflow Intrinsics</a><a class="headerlink" href="#arithmetic-with-overflow-intrinsics" title="Permalink to this headline">¶</a></h3>
+<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
+<div class="section" id="llvm-sadd-with-overflow-intrinsics">
+<h4><a class="toc-backref" href="#id1244">‘<tt class="docutils literal"><span class="pre">llvm.sadd.with.overflow.*</span></tt>‘ Intrinsics</a><a class="headerlink" href="#llvm-sadd-with-overflow-intrinsics" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id458">
+<h5><a class="toc-backref" href="#id1245">Syntax:</a><a class="headerlink" href="#id458" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.sadd.with.overflow</span></tt>
+on any integer bit width.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
+declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
+declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id459">
+<h5><a class="toc-backref" href="#id1246">Overview:</a><a class="headerlink" href="#id459" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.sadd.with.overflow</span></tt>‘ family of intrinsic functions perform
+a signed addition of the two arguments, and indicate whether an overflow
+occurred during the signed summation.</p>
+</div>
+<div class="section" id="id460">
+<h5><a class="toc-backref" href="#id1247">Arguments:</a><a class="headerlink" href="#id460" title="Permalink to this headline">¶</a></h5>
+<p>The arguments (%a and %b) and the first element of the result structure
+may be of integer types of any bit width, but they must have the same
+bit width. The second element of the result structure must be of type
+<tt class="docutils literal"><span class="pre">i1</span></tt>. <tt class="docutils literal"><span class="pre">%a</span></tt> and <tt class="docutils literal"><span class="pre">%b</span></tt> are the two values that will undergo signed
+addition.</p>
+</div>
+<div class="section" id="id461">
+<h5><a class="toc-backref" href="#id1248">Semantics:</a><a class="headerlink" href="#id461" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.sadd.with.overflow</span></tt>‘ family of intrinsic functions perform
+a signed addition of the two variables. They return a structure — the
+first element of which is the signed summation, and the second element
+of which is a bit specifying if the signed summation resulted in an
+overflow.</p>
+</div>
+<div class="section" id="id462">
+<h5><a class="toc-backref" href="#id1249">Examples:</a><a class="headerlink" href="#id462" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%res</span> <span class="p">=</span> <span class="k">call</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="vg">@llvm.sadd.with.overflow.i32</span><span class="p">(</span><span class="k">i32</span> <span class="nv">%a</span><span class="p">,</span> <span class="k">i32</span> <span class="nv">%b</span><span class="p">)</span>
+<span class="nv">%sum</span> <span class="p">=</span> <span class="k">extractvalue</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="nv">%res</span><span class="p">,</span> <span class="m">0</span>
+<span class="nv">%obit</span> <span class="p">=</span> <span class="k">extractvalue</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="nv">%res</span><span class="p">,</span> <span class="m">1</span>
+<span class="k">br</span> <span class="k">i1</span> <span class="nv">%obit</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%overflow</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%normal</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="llvm-uadd-with-overflow-intrinsics">
+<h4><a class="toc-backref" href="#id1250">‘<tt class="docutils literal"><span class="pre">llvm.uadd.with.overflow.*</span></tt>‘ Intrinsics</a><a class="headerlink" href="#llvm-uadd-with-overflow-intrinsics" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id463">
+<h5><a class="toc-backref" href="#id1251">Syntax:</a><a class="headerlink" href="#id463" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.uadd.with.overflow</span></tt>
+on any integer bit width.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
+declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
+declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id464">
+<h5><a class="toc-backref" href="#id1252">Overview:</a><a class="headerlink" href="#id464" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.uadd.with.overflow</span></tt>‘ family of intrinsic functions perform
+an unsigned addition of the two arguments, and indicate whether a carry
+occurred during the unsigned summation.</p>
+</div>
+<div class="section" id="id465">
+<h5><a class="toc-backref" href="#id1253">Arguments:</a><a class="headerlink" href="#id465" title="Permalink to this headline">¶</a></h5>
+<p>The arguments (%a and %b) and the first element of the result structure
+may be of integer types of any bit width, but they must have the same
+bit width. The second element of the result structure must be of type
+<tt class="docutils literal"><span class="pre">i1</span></tt>. <tt class="docutils literal"><span class="pre">%a</span></tt> and <tt class="docutils literal"><span class="pre">%b</span></tt> are the two values that will undergo unsigned
+addition.</p>
+</div>
+<div class="section" id="id466">
+<h5><a class="toc-backref" href="#id1254">Semantics:</a><a class="headerlink" href="#id466" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.uadd.with.overflow</span></tt>‘ family of intrinsic functions perform
+an unsigned addition of the two arguments. They return a structure — the
+first element of which is the sum, and the second element of which is a
+bit specifying if the unsigned summation resulted in a carry.</p>
+</div>
+<div class="section" id="id467">
+<h5><a class="toc-backref" href="#id1255">Examples:</a><a class="headerlink" href="#id467" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%res</span> <span class="p">=</span> <span class="k">call</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="vg">@llvm.uadd.with.overflow.i32</span><span class="p">(</span><span class="k">i32</span> <span class="nv">%a</span><span class="p">,</span> <span class="k">i32</span> <span class="nv">%b</span><span class="p">)</span>
+<span class="nv">%sum</span> <span class="p">=</span> <span class="k">extractvalue</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="nv">%res</span><span class="p">,</span> <span class="m">0</span>
+<span class="nv">%obit</span> <span class="p">=</span> <span class="k">extractvalue</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="nv">%res</span><span class="p">,</span> <span class="m">1</span>
+<span class="k">br</span> <span class="k">i1</span> <span class="nv">%obit</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%carry</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%normal</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="llvm-ssub-with-overflow-intrinsics">
+<h4><a class="toc-backref" href="#id1256">‘<tt class="docutils literal"><span class="pre">llvm.ssub.with.overflow.*</span></tt>‘ Intrinsics</a><a class="headerlink" href="#llvm-ssub-with-overflow-intrinsics" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id468">
+<h5><a class="toc-backref" href="#id1257">Syntax:</a><a class="headerlink" href="#id468" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.ssub.with.overflow</span></tt>
+on any integer bit width.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
+declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
+declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id469">
+<h5><a class="toc-backref" href="#id1258">Overview:</a><a class="headerlink" href="#id469" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.ssub.with.overflow</span></tt>‘ family of intrinsic functions perform
+a signed subtraction of the two arguments, and indicate whether an
+overflow occurred during the signed subtraction.</p>
+</div>
+<div class="section" id="id470">
+<h5><a class="toc-backref" href="#id1259">Arguments:</a><a class="headerlink" href="#id470" title="Permalink to this headline">¶</a></h5>
+<p>The arguments (%a and %b) and the first element of the result structure
+may be of integer types of any bit width, but they must have the same
+bit width. The second element of the result structure must be of type
+<tt class="docutils literal"><span class="pre">i1</span></tt>. <tt class="docutils literal"><span class="pre">%a</span></tt> and <tt class="docutils literal"><span class="pre">%b</span></tt> are the two values that will undergo signed
+subtraction.</p>
+</div>
+<div class="section" id="id471">
+<h5><a class="toc-backref" href="#id1260">Semantics:</a><a class="headerlink" href="#id471" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.ssub.with.overflow</span></tt>‘ family of intrinsic functions perform
+a signed subtraction of the two arguments. They return a structure — the
+first element of which is the subtraction, and the second element of
+which is a bit specifying if the signed subtraction resulted in an
+overflow.</p>
+</div>
+<div class="section" id="id472">
+<h5><a class="toc-backref" href="#id1261">Examples:</a><a class="headerlink" href="#id472" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%res</span> <span class="p">=</span> <span class="k">call</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="vg">@llvm.ssub.with.overflow.i32</span><span class="p">(</span><span class="k">i32</span> <span class="nv">%a</span><span class="p">,</span> <span class="k">i32</span> <span class="nv">%b</span><span class="p">)</span>
+<span class="nv">%sum</span> <span class="p">=</span> <span class="k">extractvalue</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="nv">%res</span><span class="p">,</span> <span class="m">0</span>
+<span class="nv">%obit</span> <span class="p">=</span> <span class="k">extractvalue</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="nv">%res</span><span class="p">,</span> <span class="m">1</span>
+<span class="k">br</span> <span class="k">i1</span> <span class="nv">%obit</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%overflow</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%normal</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="llvm-usub-with-overflow-intrinsics">
+<h4><a class="toc-backref" href="#id1262">‘<tt class="docutils literal"><span class="pre">llvm.usub.with.overflow.*</span></tt>‘ Intrinsics</a><a class="headerlink" href="#llvm-usub-with-overflow-intrinsics" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id473">
+<h5><a class="toc-backref" href="#id1263">Syntax:</a><a class="headerlink" href="#id473" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.usub.with.overflow</span></tt>
+on any integer bit width.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
+declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
+declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id474">
+<h5><a class="toc-backref" href="#id1264">Overview:</a><a class="headerlink" href="#id474" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.usub.with.overflow</span></tt>‘ family of intrinsic functions perform
+an unsigned subtraction of the two arguments, and indicate whether an
+overflow occurred during the unsigned subtraction.</p>
+</div>
+<div class="section" id="id475">
+<h5><a class="toc-backref" href="#id1265">Arguments:</a><a class="headerlink" href="#id475" title="Permalink to this headline">¶</a></h5>
+<p>The arguments (%a and %b) and the first element of the result structure
+may be of integer types of any bit width, but they must have the same
+bit width. The second element of the result structure must be of type
+<tt class="docutils literal"><span class="pre">i1</span></tt>. <tt class="docutils literal"><span class="pre">%a</span></tt> and <tt class="docutils literal"><span class="pre">%b</span></tt> are the two values that will undergo unsigned
+subtraction.</p>
+</div>
+<div class="section" id="id476">
+<h5><a class="toc-backref" href="#id1266">Semantics:</a><a class="headerlink" href="#id476" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.usub.with.overflow</span></tt>‘ family of intrinsic functions perform
+an unsigned subtraction of the two arguments. They return a structure —
+the first element of which is the subtraction, and the second element of
+which is a bit specifying if the unsigned subtraction resulted in an
+overflow.</p>
+</div>
+<div class="section" id="id477">
+<h5><a class="toc-backref" href="#id1267">Examples:</a><a class="headerlink" href="#id477" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%res</span> <span class="p">=</span> <span class="k">call</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="vg">@llvm.usub.with.overflow.i32</span><span class="p">(</span><span class="k">i32</span> <span class="nv">%a</span><span class="p">,</span> <span class="k">i32</span> <span class="nv">%b</span><span class="p">)</span>
+<span class="nv">%sum</span> <span class="p">=</span> <span class="k">extractvalue</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="nv">%res</span><span class="p">,</span> <span class="m">0</span>
+<span class="nv">%obit</span> <span class="p">=</span> <span class="k">extractvalue</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="nv">%res</span><span class="p">,</span> <span class="m">1</span>
+<span class="k">br</span> <span class="k">i1</span> <span class="nv">%obit</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%overflow</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%normal</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="llvm-smul-with-overflow-intrinsics">
+<h4><a class="toc-backref" href="#id1268">‘<tt class="docutils literal"><span class="pre">llvm.smul.with.overflow.*</span></tt>‘ Intrinsics</a><a class="headerlink" href="#llvm-smul-with-overflow-intrinsics" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id478">
+<h5><a class="toc-backref" href="#id1269">Syntax:</a><a class="headerlink" href="#id478" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.smul.with.overflow</span></tt>
+on any integer bit width.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
+declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
+declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id479">
+<h5><a class="toc-backref" href="#id1270">Overview:</a><a class="headerlink" href="#id479" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.smul.with.overflow</span></tt>‘ family of intrinsic functions perform
+a signed multiplication of the two arguments, and indicate whether an
+overflow occurred during the signed multiplication.</p>
+</div>
+<div class="section" id="id480">
+<h5><a class="toc-backref" href="#id1271">Arguments:</a><a class="headerlink" href="#id480" title="Permalink to this headline">¶</a></h5>
+<p>The arguments (%a and %b) and the first element of the result structure
+may be of integer types of any bit width, but they must have the same
+bit width. The second element of the result structure must be of type
+<tt class="docutils literal"><span class="pre">i1</span></tt>. <tt class="docutils literal"><span class="pre">%a</span></tt> and <tt class="docutils literal"><span class="pre">%b</span></tt> are the two values that will undergo signed
+multiplication.</p>
+</div>
+<div class="section" id="id481">
+<h5><a class="toc-backref" href="#id1272">Semantics:</a><a class="headerlink" href="#id481" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.smul.with.overflow</span></tt>‘ family of intrinsic functions perform
+a signed multiplication of the two arguments. They return a structure —
+the first element of which is the multiplication, and the second element
+of which is a bit specifying if the signed multiplication resulted in an
+overflow.</p>
+</div>
+<div class="section" id="id482">
+<h5><a class="toc-backref" href="#id1273">Examples:</a><a class="headerlink" href="#id482" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%res</span> <span class="p">=</span> <span class="k">call</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="vg">@llvm.smul.with.overflow.i32</span><span class="p">(</span><span class="k">i32</span> <span class="nv">%a</span><span class="p">,</span> <span class="k">i32</span> <span class="nv">%b</span><span class="p">)</span>
+<span class="nv">%sum</span> <span class="p">=</span> <span class="k">extractvalue</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="nv">%res</span><span class="p">,</span> <span class="m">0</span>
+<span class="nv">%obit</span> <span class="p">=</span> <span class="k">extractvalue</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="nv">%res</span><span class="p">,</span> <span class="m">1</span>
+<span class="k">br</span> <span class="k">i1</span> <span class="nv">%obit</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%overflow</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%normal</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="llvm-umul-with-overflow-intrinsics">
+<h4><a class="toc-backref" href="#id1274">‘<tt class="docutils literal"><span class="pre">llvm.umul.with.overflow.*</span></tt>‘ Intrinsics</a><a class="headerlink" href="#llvm-umul-with-overflow-intrinsics" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id483">
+<h5><a class="toc-backref" href="#id1275">Syntax:</a><a class="headerlink" href="#id483" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.umul.with.overflow</span></tt>
+on any integer bit width.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
+declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
+declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id484">
+<h5><a class="toc-backref" href="#id1276">Overview:</a><a class="headerlink" href="#id484" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.umul.with.overflow</span></tt>‘ family of intrinsic functions perform
+a unsigned multiplication of the two arguments, and indicate whether an
+overflow occurred during the unsigned multiplication.</p>
+</div>
+<div class="section" id="id485">
+<h5><a class="toc-backref" href="#id1277">Arguments:</a><a class="headerlink" href="#id485" title="Permalink to this headline">¶</a></h5>
+<p>The arguments (%a and %b) and the first element of the result structure
+may be of integer types of any bit width, but they must have the same
+bit width. The second element of the result structure must be of type
+<tt class="docutils literal"><span class="pre">i1</span></tt>. <tt class="docutils literal"><span class="pre">%a</span></tt> and <tt class="docutils literal"><span class="pre">%b</span></tt> are the two values that will undergo unsigned
+multiplication.</p>
+</div>
+<div class="section" id="id486">
+<h5><a class="toc-backref" href="#id1278">Semantics:</a><a class="headerlink" href="#id486" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.umul.with.overflow</span></tt>‘ family of intrinsic functions perform
+an unsigned multiplication of the two arguments. They return a structure —
+the first element of which is the multiplication, and the second
+element of which is a bit specifying if the unsigned multiplication
+resulted in an overflow.</p>
+</div>
+<div class="section" id="id487">
+<h5><a class="toc-backref" href="#id1279">Examples:</a><a class="headerlink" href="#id487" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%res</span> <span class="p">=</span> <span class="k">call</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="vg">@llvm.umul.with.overflow.i32</span><span class="p">(</span><span class="k">i32</span> <span class="nv">%a</span><span class="p">,</span> <span class="k">i32</span> <span class="nv">%b</span><span class="p">)</span>
+<span class="nv">%sum</span> <span class="p">=</span> <span class="k">extractvalue</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="nv">%res</span><span class="p">,</span> <span class="m">0</span>
+<span class="nv">%obit</span> <span class="p">=</span> <span class="k">extractvalue</span> <span class="p">{</span><span class="k">i32</span><span class="p">,</span> <span class="k">i1</span><span class="p">}</span> <span class="nv">%res</span><span class="p">,</span> <span class="m">1</span>
+<span class="k">br</span> <span class="k">i1</span> <span class="nv">%obit</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%overflow</span><span class="p">,</span> <span class="kt">label</span> <span class="nv">%normal</span>
+</pre></div>
+</div>
+</div>
+</div>
+</div>
+<div class="section" id="specialised-arithmetic-intrinsics">
+<h3><a class="toc-backref" href="#id1280">Specialised Arithmetic Intrinsics</a><a class="headerlink" href="#specialised-arithmetic-intrinsics" title="Permalink to this headline">¶</a></h3>
+<div class="section" id="llvm-fmuladd-intrinsic">
+<h4><a class="toc-backref" href="#id1281">‘<tt class="docutils literal"><span class="pre">llvm.fmuladd.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-fmuladd-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id488">
+<h5><a class="toc-backref" href="#id1282">Syntax:</a><a class="headerlink" href="#id488" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare float @llvm.fmuladd.f32(float %a, float %b, float %c)
+declare double @llvm.fmuladd.f64(double %a, double %b, double %c)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id489">
+<h5><a class="toc-backref" href="#id1283">Overview:</a><a class="headerlink" href="#id489" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.fmuladd.*</span></tt>‘ intrinsic functions represent multiply-add
+expressions that can be fused if the code generator determines that (a) the
+target instruction set has support for a fused operation, and (b) that the
+fused operation is more efficient than the equivalent, separate pair of mul
+and add instructions.</p>
+</div>
+<div class="section" id="id490">
+<h5><a class="toc-backref" href="#id1284">Arguments:</a><a class="headerlink" href="#id490" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.fmuladd.*</span></tt>‘ intrinsics each take three arguments: two
+multiplicands, a and b, and an addend c.</p>
+</div>
+<div class="section" id="id491">
+<h5><a class="toc-backref" href="#id1285">Semantics:</a><a class="headerlink" href="#id491" title="Permalink to this headline">¶</a></h5>
+<p>The expression:</p>
+<div class="highlight-python"><div class="highlight"><pre>%0 = call float @llvm.fmuladd.f32(%a, %b, %c)
+</pre></div>
+</div>
+<p>is equivalent to the expression a * b + c, except that rounding will
+not be performed between the multiplication and addition steps if the
+code generator fuses the operations. Fusion is not guaranteed, even if
+the target platform supports it. If a fused multiply-add is required the
+corresponding llvm.fma.* intrinsic function should be used
+instead. This never sets errno, just as ‘<tt class="docutils literal"><span class="pre">llvm.fma.*</span></tt>‘.</p>
+</div>
+<div class="section" id="id492">
+<h5><a class="toc-backref" href="#id1286">Examples:</a><a class="headerlink" href="#id492" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%r2</span> <span class="p">=</span> <span class="k">call</span> <span class="kt">float</span> <span class="vg">@llvm.fmuladd.f32</span><span class="p">(</span><span class="kt">float</span> <span class="nv">%a</span><span class="p">,</span> <span class="kt">float</span> <span class="nv">%b</span><span class="p">,</span> <span class="kt">float</span> <span class="nv">%c</span><span class="p">)</span> <span class="c">; yields float:r2 = (a * b) + c</span>
+</pre></div>
+</div>
+</div>
+</div>
+</div>
+<div class="section" id="half-precision-floating-point-intrinsics">
+<h3><a class="toc-backref" href="#id1287">Half Precision Floating Point Intrinsics</a><a class="headerlink" href="#half-precision-floating-point-intrinsics" title="Permalink to this headline">¶</a></h3>
+<p>For most target platforms, half precision floating point is a
+storage-only format. This means that it is a dense encoding (in memory)
+but does not support computation in the format.</p>
+<p>This means that code must first load the half-precision floating point
+value as an i16, then convert it to float with
+<a class="reference internal" href="#int-convert-from-fp16"><em>llvm.convert.from.fp16</em></a>. Computation can
+then be performed on the float value (including extending to double
+etc). To store the value back to memory, it is first converted to float
+if needed, then converted to i16 with
+<a class="reference internal" href="#int-convert-to-fp16"><em>llvm.convert.to.fp16</em></a>, then storing as an
+i16 value.</p>
+<div class="section" id="llvm-convert-to-fp16-intrinsic">
+<span id="int-convert-to-fp16"></span><h4><a class="toc-backref" href="#id1288">‘<tt class="docutils literal"><span class="pre">llvm.convert.to.fp16</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-convert-to-fp16-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id493">
+<h5><a class="toc-backref" href="#id1289">Syntax:</a><a class="headerlink" href="#id493" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare i16 @llvm.convert.to.fp16.f32(float %a)
+declare i16 @llvm.convert.to.fp16.f64(double %a)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id494">
+<h5><a class="toc-backref" href="#id1290">Overview:</a><a class="headerlink" href="#id494" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.convert.to.fp16</span></tt>‘ intrinsic function performs a conversion from a
+conventional floating point type to half precision floating point format.</p>
+</div>
+<div class="section" id="id495">
+<h5><a class="toc-backref" href="#id1291">Arguments:</a><a class="headerlink" href="#id495" title="Permalink to this headline">¶</a></h5>
+<p>The intrinsic function contains single argument - the value to be
+converted.</p>
+</div>
+<div class="section" id="id496">
+<h5><a class="toc-backref" href="#id1292">Semantics:</a><a class="headerlink" href="#id496" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.convert.to.fp16</span></tt>‘ intrinsic function performs a conversion from a
+conventional floating point format to half precision floating point format. The
+return value is an <tt class="docutils literal"><span class="pre">i16</span></tt> which contains the converted number.</p>
+</div>
+<div class="section" id="id497">
+<h5><a class="toc-backref" href="#id1293">Examples:</a><a class="headerlink" href="#id497" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%res</span> <span class="p">=</span> <span class="k">call</span> <span class="k">i16</span> <span class="vg">@llvm.convert.to.fp16.f32</span><span class="p">(</span><span class="kt">float</span> <span class="nv">%a</span><span class="p">)</span>
+<span class="k">store</span> <span class="k">i16</span> <span class="nv">%res</span><span class="p">,</span> <span class="k">i16</span><span class="p">*</span> <span class="vg">@x</span><span class="p">,</span> <span class="k">align</span> <span class="m">2</span>
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="llvm-convert-from-fp16-intrinsic">
+<span id="int-convert-from-fp16"></span><h4><a class="toc-backref" href="#id1294">‘<tt class="docutils literal"><span class="pre">llvm.convert.from.fp16</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-convert-from-fp16-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id498">
+<h5><a class="toc-backref" href="#id1295">Syntax:</a><a class="headerlink" href="#id498" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare float @llvm.convert.from.fp16.f32(i16 %a)
+declare double @llvm.convert.from.fp16.f64(i16 %a)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id499">
+<h5><a class="toc-backref" href="#id1296">Overview:</a><a class="headerlink" href="#id499" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.convert.from.fp16</span></tt>‘ intrinsic function performs a
+conversion from half precision floating point format to single precision
+floating point format.</p>
+</div>
+<div class="section" id="id500">
+<h5><a class="toc-backref" href="#id1297">Arguments:</a><a class="headerlink" href="#id500" title="Permalink to this headline">¶</a></h5>
+<p>The intrinsic function contains single argument - the value to be
+converted.</p>
+</div>
+<div class="section" id="id501">
+<h5><a class="toc-backref" href="#id1298">Semantics:</a><a class="headerlink" href="#id501" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.convert.from.fp16</span></tt>‘ intrinsic function performs a
+conversion from half single precision floating point format to single
+precision floating point format. The input half-float value is
+represented by an <tt class="docutils literal"><span class="pre">i16</span></tt> value.</p>
+</div>
+<div class="section" id="id502">
+<h5><a class="toc-backref" href="#id1299">Examples:</a><a class="headerlink" href="#id502" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%a</span> <span class="p">=</span> <span class="k">load</span> <span class="k">i16</span><span class="p">*</span> <span class="vg">@x</span><span class="p">,</span> <span class="k">align</span> <span class="m">2</span>
+<span class="nv">%res</span> <span class="p">=</span> <span class="k">call</span> <span class="kt">float</span> <span class="vg">@llvm.convert.from.fp16</span><span class="p">(</span><span class="k">i16</span> <span class="nv">%a</span><span class="p">)</span>
+</pre></div>
+</div>
+</div>
+</div>
+</div>
+<div class="section" id="debugger-intrinsics">
+<h3><a class="toc-backref" href="#id1300">Debugger Intrinsics</a><a class="headerlink" href="#debugger-intrinsics" title="Permalink to this headline">¶</a></h3>
+<p>The LLVM debugger intrinsics (which all start with <tt class="docutils literal"><span class="pre">llvm.dbg.</span></tt>
+prefix), are described in the <a class="reference external" href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
+Debugging</a>
+document.</p>
+</div>
+<div class="section" id="exception-handling-intrinsics">
+<h3><a class="toc-backref" href="#id1301">Exception Handling Intrinsics</a><a class="headerlink" href="#exception-handling-intrinsics" title="Permalink to this headline">¶</a></h3>
+<p>The LLVM exception handling intrinsics (which all start with
+<tt class="docutils literal"><span class="pre">llvm.eh.</span></tt> prefix), are described in the <a class="reference external" href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
+Handling</a> document.</p>
+</div>
+<div class="section" id="trampoline-intrinsics">
+<span id="int-trampoline"></span><h3><a class="toc-backref" href="#id1302">Trampoline Intrinsics</a><a class="headerlink" href="#trampoline-intrinsics" title="Permalink to this headline">¶</a></h3>
+<p>These intrinsics make it possible to excise one parameter, marked with
+the <a class="reference internal" href="#nest"><em>nest</em></a> attribute, from a function. The result is a
+callable function pointer lacking the nest parameter - the caller does
+not need to provide a value for it. Instead, the value to use is stored
+in advance in a “trampoline”, a block of memory usually allocated on the
+stack, which also contains code to splice the nest value into the
+argument list. This is used to implement the GCC nested function address
+extension.</p>
+<p>For example, if the function is <tt class="docutils literal"><span class="pre">i32</span> <span class="pre">f(i8*</span> <span class="pre">nest</span> <span class="pre">%c,</span> <span class="pre">i32</span> <span class="pre">%x,</span> <span class="pre">i32</span> <span class="pre">%y)</span></tt>
+then the resulting function pointer has signature <tt class="docutils literal"><span class="pre">i32</span> <span class="pre">(i32,</span> <span class="pre">i32)*</span></tt>.
+It can be created as follows:</p>
+<div class="highlight-llvm"><div class="highlight"><pre><span class="nv">%tramp</span> <span class="p">=</span> <span class="k">alloca</span> <span class="p">[</span><span class="m">10</span> <span class="k">x</span> <span class="k">i8</span><span class="p">],</span> <span class="k">align</span> <span class="m">4</span> <span class="c">; size and alignment only correct for X86</span>
+<span class="nv">%tramp1</span> <span class="p">=</span> <span class="k">getelementptr</span> <span class="p">[</span><span class="m">10</span> <span class="k">x</span> <span class="k">i8</span><span class="p">]*</span> <span class="nv">%tramp</span><span class="p">,</span> <span class="k">i32</span> <span class="m">0</span><span class="p">,</span> <span class="k">i32</span> <span class="m">0</span>
+<span class="k">call</span> <span class="k">i8</span><span class="p">*</span> <span class="vg">@llvm.init.trampoline</span><span class="p">(</span><span class="k">i8</span><span class="p">*</span> <span class="nv">%tramp1</span><span class="p">,</span> <span class="k">i8</span><span class="p">*</span> <span class="k">bitcast</span> <span class="p">(</span><span class="k">i32</span> <span class="p">(</span><span class="k">i8</span><span class="p">*,</span> <span class="k">i32</span><span class="p">,</span> <span class="k">i32</span><span class="p">)*</span> <span class="vg">@f</span> <span class="k">to</span> <span class="k">i8</span><span class="p">*),</span> <span class="k">i8</span><span class="p">*</span> <span class="nv">%nval</span><span class="p">)</span>
+<span class="nv">%p</span> <span class="p">=</span> <span class="k">call</span> <span class="k">i8</span><span class="p">*</span> <span class="vg">@llvm.adjust.trampoline</span><span class="p">(</span><span class="k">i8</span><span class="p">*</span> <span class="nv">%tramp1</span><span class="p">)</span>
+<span class="nv">%fp</span> <span class="p">=</span> <span class="k">bitcast</span> <span class="k">i8</span><span class="p">*</span> <span class="nv">%p</span> <span class="k">to</span> <span class="k">i32</span> <span class="p">(</span><span class="k">i32</span><span class="p">,</span> <span class="k">i32</span><span class="p">)*</span>
+</pre></div>
+</div>
+<p>The call <tt class="docutils literal"><span class="pre">%val</span> <span class="pre">=</span> <span class="pre">call</span> <span class="pre">i32</span> <span class="pre">%fp(i32</span> <span class="pre">%x,</span> <span class="pre">i32</span> <span class="pre">%y)</span></tt> is then equivalent to
+<tt class="docutils literal"><span class="pre">%val</span> <span class="pre">=</span> <span class="pre">call</span> <span class="pre">i32</span> <span class="pre">%f(i8*</span> <span class="pre">%nval,</span> <span class="pre">i32</span> <span class="pre">%x,</span> <span class="pre">i32</span> <span class="pre">%y)</span></tt>.</p>
+<div class="section" id="llvm-init-trampoline-intrinsic">
+<span id="int-it"></span><h4><a class="toc-backref" href="#id1303">‘<tt class="docutils literal"><span class="pre">llvm.init.trampoline</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-init-trampoline-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id503">
+<h5><a class="toc-backref" href="#id1304">Syntax:</a><a class="headerlink" href="#id503" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id504">
+<h5><a class="toc-backref" href="#id1305">Overview:</a><a class="headerlink" href="#id504" title="Permalink to this headline">¶</a></h5>
+<p>This fills the memory pointed to by <tt class="docutils literal"><span class="pre">tramp</span></tt> with executable code,
+turning it into a trampoline.</p>
+</div>
+<div class="section" id="id505">
+<h5><a class="toc-backref" href="#id1306">Arguments:</a><a class="headerlink" href="#id505" title="Permalink to this headline">¶</a></h5>
+<p>The <tt class="docutils literal"><span class="pre">llvm.init.trampoline</span></tt> intrinsic takes three arguments, all
+pointers. The <tt class="docutils literal"><span class="pre">tramp</span></tt> argument must point to a sufficiently large and
+sufficiently aligned block of memory; this memory is written to by the
+intrinsic. Note that the size and the alignment are target-specific -
+LLVM currently provides no portable way of determining them, so a
+front-end that generates this intrinsic needs to have some
+target-specific knowledge. The <tt class="docutils literal"><span class="pre">func</span></tt> argument must hold a function
+bitcast to an <tt class="docutils literal"><span class="pre">i8*</span></tt>.</p>
+</div>
+<div class="section" id="id506">
+<h5><a class="toc-backref" href="#id1307">Semantics:</a><a class="headerlink" href="#id506" title="Permalink to this headline">¶</a></h5>
+<p>The block of memory pointed to by <tt class="docutils literal"><span class="pre">tramp</span></tt> is filled with target
+dependent code, turning it into a function. Then <tt class="docutils literal"><span class="pre">tramp</span></tt> needs to be
+passed to <a class="reference internal" href="#int-at"><em>llvm.adjust.trampoline</em></a> to get a pointer which can
+be <a class="reference internal" href="#int-trampoline"><em>bitcast (to a new function) and called</em></a>. The new
+function’s signature is the same as that of <tt class="docutils literal"><span class="pre">func</span></tt> with any arguments
+marked with the <tt class="docutils literal"><span class="pre">nest</span></tt> attribute removed. At most one such <tt class="docutils literal"><span class="pre">nest</span></tt>
+argument is allowed, and it must be of pointer type. Calling the new
+function is equivalent to calling <tt class="docutils literal"><span class="pre">func</span></tt> with the same argument list,
+but with <tt class="docutils literal"><span class="pre">nval</span></tt> used for the missing <tt class="docutils literal"><span class="pre">nest</span></tt> argument. If, after
+calling <tt class="docutils literal"><span class="pre">llvm.init.trampoline</span></tt>, the memory pointed to by <tt class="docutils literal"><span class="pre">tramp</span></tt> is
+modified, then the effect of any later call to the returned function
+pointer is undefined.</p>
+</div>
+</div>
+<div class="section" id="llvm-adjust-trampoline-intrinsic">
+<span id="int-at"></span><h4><a class="toc-backref" href="#id1308">‘<tt class="docutils literal"><span class="pre">llvm.adjust.trampoline</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-adjust-trampoline-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id507">
+<h5><a class="toc-backref" href="#id1309">Syntax:</a><a class="headerlink" href="#id507" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare i8* @llvm.adjust.trampoline(i8* <tramp>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id508">
+<h5><a class="toc-backref" href="#id1310">Overview:</a><a class="headerlink" href="#id508" title="Permalink to this headline">¶</a></h5>
+<p>This performs any required machine-specific adjustment to the address of
+a trampoline (passed as <tt class="docutils literal"><span class="pre">tramp</span></tt>).</p>
+</div>
+<div class="section" id="id509">
+<h5><a class="toc-backref" href="#id1311">Arguments:</a><a class="headerlink" href="#id509" title="Permalink to this headline">¶</a></h5>
+<p><tt class="docutils literal"><span class="pre">tramp</span></tt> must point to a block of memory which already has trampoline
+code filled in by a previous call to
+<a class="reference internal" href="#int-it"><em>llvm.init.trampoline</em></a>.</p>
+</div>
+<div class="section" id="id510">
+<h5><a class="toc-backref" href="#id1312">Semantics:</a><a class="headerlink" href="#id510" title="Permalink to this headline">¶</a></h5>
+<p>On some architectures the address of the code to be executed needs to be
+different than the address where the trampoline is actually stored. This
+intrinsic returns the executable address corresponding to <tt class="docutils literal"><span class="pre">tramp</span></tt>
+after performing the required machine specific adjustments. The pointer
+returned can then be <a class="reference internal" href="#int-trampoline"><em>bitcast and executed</em></a>.</p>
+</div>
+</div>
+</div>
+<div class="section" id="masked-vector-load-and-store-intrinsics">
+<h3><a class="toc-backref" href="#id1313">Masked Vector Load and Store Intrinsics</a><a class="headerlink" href="#masked-vector-load-and-store-intrinsics" title="Permalink to this headline">¶</a></h3>
+<p>LLVM provides intrinsics for predicated vector load and store operations. The predicate is specified by a mask operand, which holds one bit per vector element, switching the associated vector lane on or off. The memory addresses corresponding to the “off” lanes are not accessed. When all bits of the mask are on, the intrinsic is identical to a regular vector load or store. When all bits are off, no memory is accessed.</p>
+<div class="section" id="llvm-masked-load-intrinsics">
+<span id="int-mload"></span><h4><a class="toc-backref" href="#id1314">‘<tt class="docutils literal"><span class="pre">llvm.masked.load.*</span></tt>‘ Intrinsics</a><a class="headerlink" href="#llvm-masked-load-intrinsics" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id511">
+<h5><a class="toc-backref" href="#id1315">Syntax:</a><a class="headerlink" href="#id511" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. The loaded data is a vector of any integer or floating point data type.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare <16 x float> @llvm.masked.load.v16f32 (<16 x float>* <ptr>, i32 <alignment>, <16 x i1> <mask>, <16 x float> <passthru>)
+declare <2 x double> @llvm.masked.load.v2f64  (<2 x double>* <ptr>, i32 <alignment>, <2 x i1>  <mask>, <2 x double> <passthru>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id512">
+<h5><a class="toc-backref" href="#id1316">Overview:</a><a class="headerlink" href="#id512" title="Permalink to this headline">¶</a></h5>
+<p>Reads a vector from memory according to the provided mask. The mask holds a bit for each vector lane, and is used to prevent memory accesses to the masked-off lanes. The masked-off lanes in the result vector are taken from the corresponding lanes in the passthru operand.</p>
+</div>
+<div class="section" id="id513">
+<h5><a class="toc-backref" href="#id1317">Arguments:</a><a class="headerlink" href="#id513" title="Permalink to this headline">¶</a></h5>
+<p>The first operand is the base pointer for the load. The second operand is the alignment of the source location. It must be a constant integer value. The third operand, mask, is a vector of boolean ‘i1’ values with the same number of elements as the return type. The fourth is a pass-through value that is used to fill the masked-off lanes of the result. The return type, underlying type of the base pointer and the type of passthru operand are the same vector types.</p>
+</div>
+<div class="section" id="id514">
+<h5><a class="toc-backref" href="#id1318">Semantics:</a><a class="headerlink" href="#id514" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.masked.load</span></tt>‘ intrinsic is designed for conditional reading of selected vector elements in a single IR operation. It is useful for targets that support vector masked loads and allows vectorizing predicated basic blocks on these targets. Other targets may support this intrinsic differently, for example by lowering it into a sequence of branches that guard scalar load operations.
+The result of this operation is equivalent to a regular vector load instruction followed by a ‘select’ between the loaded and the passthru values, predicated on the same mask. However, using this intrinsic prevents exceptions on memory access to masked-off lanes.</p>
+<div class="highlight-python"><div class="highlight"><pre>%res = call <16 x float> @llvm.masked.load.v16f32 (<16 x float>* %ptr, i32 4, <16 x i1>%mask, <16 x float> %passthru)
+
+;; The result of the two following instructions is identical aside from potential memory access exception
+%loadlal = load <16 x float>* %ptr, align 4
+%res = select <16 x i1> %mask, <16 x float> %loadlal, <16 x float> %passthru
+</pre></div>
+</div>
+</div>
+</div>
+<div class="section" id="llvm-masked-store-intrinsics">
+<span id="int-mstore"></span><h4><a class="toc-backref" href="#id1319">‘<tt class="docutils literal"><span class="pre">llvm.masked.store.*</span></tt>‘ Intrinsics</a><a class="headerlink" href="#llvm-masked-store-intrinsics" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id515">
+<h5><a class="toc-backref" href="#id1320">Syntax:</a><a class="headerlink" href="#id515" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. The data stored in memory is a vector of any integer or floating point data type.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.masked.store.v8i32 (<8 x i32>  <value>, <8 x i32> * <ptr>, i32 <alignment>,  <8 x i1>  <mask>)
+declare void @llvm.masked.store.v16f32(<16 x i32> <value>, <16 x i32>* <ptr>, i32 <alignment>,  <16 x i1> <mask>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id516">
+<h5><a class="toc-backref" href="#id1321">Overview:</a><a class="headerlink" href="#id516" title="Permalink to this headline">¶</a></h5>
+<p>Writes a vector to memory according to the provided mask. The mask holds a bit for each vector lane, and is used to prevent memory accesses to the masked-off lanes.</p>
+</div>
+<div class="section" id="id517">
+<h5><a class="toc-backref" href="#id1322">Arguments:</a><a class="headerlink" href="#id517" title="Permalink to this headline">¶</a></h5>
+<p>The first operand is the vector value to be written to memory. The second operand is the base pointer for the store, it has the same underlying type as the value operand. The third operand is the alignment of the destination location. The fourth operand, mask, is a vector of boolean values. The types of the mask and the value operand must have the same number of vector elements.</p>
+</div>
+<div class="section" id="id518">
+<h5><a class="toc-backref" href="#id1323">Semantics:</a><a class="headerlink" href="#id518" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.masked.store</span></tt>‘ intrinsics is designed for conditional writing of selected vector elements in a single IR operation. It is useful for targets that support vector masked store and allows vectorizing predicated basic blocks on these targets. Other targets may support this intrinsic differently, for example by lowering it into a sequence of branches that guard scalar store operations.
+The result of this operation is equivalent to a load-modify-store sequence. However, using this intrinsic prevents exceptions and data races on memory access to masked-off lanes.</p>
+<div class="highlight-python"><div class="highlight"><pre>call void @llvm.masked.store.v16f32(<16 x float> %value, <16 x float>* %ptr, i32 4,  <16 x i1> %mask)
+
+;; The result of the following instructions is identical aside from potential data races and memory access exceptions
+%oldval = load <16 x float>* %ptr, align 4
+%res = select <16 x i1> %mask, <16 x float> %value, <16 x float> %oldval
+store <16 x float> %res, <16 x float>* %ptr, align 4
+</pre></div>
+</div>
+</div>
+</div>
+</div>
+<div class="section" id="memory-use-markers">
+<h3><a class="toc-backref" href="#id1324">Memory Use Markers</a><a class="headerlink" href="#memory-use-markers" title="Permalink to this headline">¶</a></h3>
+<p>This class of intrinsics provides information about the lifetime of
+memory objects and ranges where variables are immutable.</p>
+<div class="section" id="llvm-lifetime-start-intrinsic">
+<span id="int-lifestart"></span><h4><a class="toc-backref" href="#id1325">‘<tt class="docutils literal"><span class="pre">llvm.lifetime.start</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-lifetime-start-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id519">
+<h5><a class="toc-backref" href="#id1326">Syntax:</a><a class="headerlink" href="#id519" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.lifetime.start(i64 <size>, i8* nocapture <ptr>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id520">
+<h5><a class="toc-backref" href="#id1327">Overview:</a><a class="headerlink" href="#id520" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.lifetime.start</span></tt>‘ intrinsic specifies the start of a memory
+object’s lifetime.</p>
+</div>
+<div class="section" id="id521">
+<h5><a class="toc-backref" href="#id1328">Arguments:</a><a class="headerlink" href="#id521" title="Permalink to this headline">¶</a></h5>
+<p>The first argument is a constant integer representing the size of the
+object, or -1 if it is variable sized. The second argument is a pointer
+to the object.</p>
+</div>
+<div class="section" id="id522">
+<h5><a class="toc-backref" href="#id1329">Semantics:</a><a class="headerlink" href="#id522" title="Permalink to this headline">¶</a></h5>
+<p>This intrinsic indicates that before this point in the code, the value
+of the memory pointed to by <tt class="docutils literal"><span class="pre">ptr</span></tt> is dead. This means that it is known
+to never be used and has an undefined value. A load from the pointer
+that precedes this intrinsic can be replaced with <tt class="docutils literal"><span class="pre">'undef'</span></tt>.</p>
+</div>
+</div>
+<div class="section" id="llvm-lifetime-end-intrinsic">
+<span id="int-lifeend"></span><h4><a class="toc-backref" href="#id1330">‘<tt class="docutils literal"><span class="pre">llvm.lifetime.end</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-lifetime-end-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id523">
+<h5><a class="toc-backref" href="#id1331">Syntax:</a><a class="headerlink" href="#id523" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.lifetime.end(i64 <size>, i8* nocapture <ptr>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id524">
+<h5><a class="toc-backref" href="#id1332">Overview:</a><a class="headerlink" href="#id524" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.lifetime.end</span></tt>‘ intrinsic specifies the end of a memory
+object’s lifetime.</p>
+</div>
+<div class="section" id="id525">
+<h5><a class="toc-backref" href="#id1333">Arguments:</a><a class="headerlink" href="#id525" title="Permalink to this headline">¶</a></h5>
+<p>The first argument is a constant integer representing the size of the
+object, or -1 if it is variable sized. The second argument is a pointer
+to the object.</p>
+</div>
+<div class="section" id="id526">
+<h5><a class="toc-backref" href="#id1334">Semantics:</a><a class="headerlink" href="#id526" title="Permalink to this headline">¶</a></h5>
+<p>This intrinsic indicates that after this point in the code, the value of
+the memory pointed to by <tt class="docutils literal"><span class="pre">ptr</span></tt> is dead. This means that it is known to
+never be used and has an undefined value. Any stores into the memory
+object following this intrinsic may be removed as dead.</p>
+</div>
+</div>
+<div class="section" id="llvm-invariant-start-intrinsic">
+<h4><a class="toc-backref" href="#id1335">‘<tt class="docutils literal"><span class="pre">llvm.invariant.start</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-invariant-start-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id527">
+<h5><a class="toc-backref" href="#id1336">Syntax:</a><a class="headerlink" href="#id527" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare {}* @llvm.invariant.start(i64 <size>, i8* nocapture <ptr>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id528">
+<h5><a class="toc-backref" href="#id1337">Overview:</a><a class="headerlink" href="#id528" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.invariant.start</span></tt>‘ intrinsic specifies that the contents of
+a memory object will not change.</p>
+</div>
+<div class="section" id="id529">
+<h5><a class="toc-backref" href="#id1338">Arguments:</a><a class="headerlink" href="#id529" title="Permalink to this headline">¶</a></h5>
+<p>The first argument is a constant integer representing the size of the
+object, or -1 if it is variable sized. The second argument is a pointer
+to the object.</p>
+</div>
+<div class="section" id="id530">
+<h5><a class="toc-backref" href="#id1339">Semantics:</a><a class="headerlink" href="#id530" title="Permalink to this headline">¶</a></h5>
+<p>This intrinsic indicates that until an <tt class="docutils literal"><span class="pre">llvm.invariant.end</span></tt> that uses
+the return value, the referenced memory location is constant and
+unchanging.</p>
+</div>
+</div>
+<div class="section" id="llvm-invariant-end-intrinsic">
+<h4><a class="toc-backref" href="#id1340">‘<tt class="docutils literal"><span class="pre">llvm.invariant.end</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-invariant-end-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id531">
+<h5><a class="toc-backref" href="#id1341">Syntax:</a><a class="headerlink" href="#id531" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.invariant.end({}* <start>, i64 <size>, i8* nocapture <ptr>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id532">
+<h5><a class="toc-backref" href="#id1342">Overview:</a><a class="headerlink" href="#id532" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.invariant.end</span></tt>‘ intrinsic specifies that the contents of a
+memory object are mutable.</p>
+</div>
+<div class="section" id="id533">
+<h5><a class="toc-backref" href="#id1343">Arguments:</a><a class="headerlink" href="#id533" title="Permalink to this headline">¶</a></h5>
+<p>The first argument is the matching <tt class="docutils literal"><span class="pre">llvm.invariant.start</span></tt> intrinsic.
+The second argument is a constant integer representing the size of the
+object, or -1 if it is variable sized and the third argument is a
+pointer to the object.</p>
+</div>
+<div class="section" id="id534">
+<h5><a class="toc-backref" href="#id1344">Semantics:</a><a class="headerlink" href="#id534" title="Permalink to this headline">¶</a></h5>
+<p>This intrinsic indicates that the memory is mutable again.</p>
+</div>
+</div>
+</div>
+<div class="section" id="general-intrinsics">
+<h3><a class="toc-backref" href="#id1345">General Intrinsics</a><a class="headerlink" href="#general-intrinsics" title="Permalink to this headline">¶</a></h3>
+<p>This class of intrinsics is designed to be generic and has no specific
+purpose.</p>
+<div class="section" id="llvm-var-annotation-intrinsic">
+<h4><a class="toc-backref" href="#id1346">‘<tt class="docutils literal"><span class="pre">llvm.var.annotation</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-var-annotation-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id535">
+<h5><a class="toc-backref" href="#id1347">Syntax:</a><a class="headerlink" href="#id535" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.var.annotation(i8* <val>, i8* <str>, i8* <str>, i32  <int>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id536">
+<h5><a class="toc-backref" href="#id1348">Overview:</a><a class="headerlink" href="#id536" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.var.annotation</span></tt>‘ intrinsic.</p>
+</div>
+<div class="section" id="id537">
+<h5><a class="toc-backref" href="#id1349">Arguments:</a><a class="headerlink" href="#id537" title="Permalink to this headline">¶</a></h5>
+<p>The first argument is a pointer to a value, the second is a pointer to a
+global string, the third is a pointer to a global string which is the
+source file name, and the last argument is the line number.</p>
+</div>
+<div class="section" id="id538">
+<h5><a class="toc-backref" href="#id1350">Semantics:</a><a class="headerlink" href="#id538" title="Permalink to this headline">¶</a></h5>
+<p>This intrinsic allows annotation of local variables with arbitrary
+strings. This can be useful for special purpose optimizations that want
+to look for these annotations. These have no other defined use; they are
+ignored by code generation and optimization.</p>
+</div>
+</div>
+<div class="section" id="llvm-ptr-annotation-intrinsic">
+<h4><a class="toc-backref" href="#id1351">‘<tt class="docutils literal"><span class="pre">llvm.ptr.annotation.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-ptr-annotation-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id539">
+<h5><a class="toc-backref" href="#id1352">Syntax:</a><a class="headerlink" href="#id539" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use ‘<tt class="docutils literal"><span class="pre">llvm.ptr.annotation</span></tt>‘ on a
+pointer to an integer of any width. <em>NOTE</em> you must specify an address space for
+the pointer. The identifier for the default address space is the integer
+‘<tt class="docutils literal"><span class="pre">0</span></tt>‘.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare i8*   @llvm.ptr.annotation.p<address space>i8(i8* <val>, i8* <str>, i8* <str>, i32  <int>)
+declare i16*  @llvm.ptr.annotation.p<address space>i16(i16* <val>, i8* <str>, i8* <str>, i32  <int>)
+declare i32*  @llvm.ptr.annotation.p<address space>i32(i32* <val>, i8* <str>, i8* <str>, i32  <int>)
+declare i64*  @llvm.ptr.annotation.p<address space>i64(i64* <val>, i8* <str>, i8* <str>, i32  <int>)
+declare i256* @llvm.ptr.annotation.p<address space>i256(i256* <val>, i8* <str>, i8* <str>, i32  <int>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id540">
+<h5><a class="toc-backref" href="#id1353">Overview:</a><a class="headerlink" href="#id540" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.ptr.annotation</span></tt>‘ intrinsic.</p>
+</div>
+<div class="section" id="id541">
+<h5><a class="toc-backref" href="#id1354">Arguments:</a><a class="headerlink" href="#id541" title="Permalink to this headline">¶</a></h5>
+<p>The first argument is a pointer to an integer value of arbitrary bitwidth
+(result of some expression), the second is a pointer to a global string, the
+third is a pointer to a global string which is the source file name, and the
+last argument is the line number. It returns the value of the first argument.</p>
+</div>
+<div class="section" id="id542">
+<h5><a class="toc-backref" href="#id1355">Semantics:</a><a class="headerlink" href="#id542" title="Permalink to this headline">¶</a></h5>
+<p>This intrinsic allows annotation of a pointer to an integer with arbitrary
+strings. This can be useful for special purpose optimizations that want to look
+for these annotations. These have no other defined use; they are ignored by code
+generation and optimization.</p>
+</div>
+</div>
+<div class="section" id="llvm-annotation-intrinsic">
+<h4><a class="toc-backref" href="#id1356">‘<tt class="docutils literal"><span class="pre">llvm.annotation.*</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-annotation-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id543">
+<h5><a class="toc-backref" href="#id1357">Syntax:</a><a class="headerlink" href="#id543" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use ‘<tt class="docutils literal"><span class="pre">llvm.annotation</span></tt>‘ on
+any integer bit width.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32  <int>)
+declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32  <int>)
+declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32  <int>)
+declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32  <int>)
+declare i256 @llvm.annotation.i256(i256 <val>, i8* <str>, i8* <str>, i32  <int>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id544">
+<h5><a class="toc-backref" href="#id1358">Overview:</a><a class="headerlink" href="#id544" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.annotation</span></tt>‘ intrinsic.</p>
+</div>
+<div class="section" id="id545">
+<h5><a class="toc-backref" href="#id1359">Arguments:</a><a class="headerlink" href="#id545" title="Permalink to this headline">¶</a></h5>
+<p>The first argument is an integer value (result of some expression), the
+second is a pointer to a global string, the third is a pointer to a
+global string which is the source file name, and the last argument is
+the line number. It returns the value of the first argument.</p>
+</div>
+<div class="section" id="id546">
+<h5><a class="toc-backref" href="#id1360">Semantics:</a><a class="headerlink" href="#id546" title="Permalink to this headline">¶</a></h5>
+<p>This intrinsic allows annotations to be put on arbitrary expressions
+with arbitrary strings. This can be useful for special purpose
+optimizations that want to look for these annotations. These have no
+other defined use; they are ignored by code generation and optimization.</p>
+</div>
+</div>
+<div class="section" id="llvm-trap-intrinsic">
+<h4><a class="toc-backref" href="#id1361">‘<tt class="docutils literal"><span class="pre">llvm.trap</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-trap-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id547">
+<h5><a class="toc-backref" href="#id1362">Syntax:</a><a class="headerlink" href="#id547" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.trap() noreturn nounwind
+</pre></div>
+</div>
+</div>
+<div class="section" id="id548">
+<h5><a class="toc-backref" href="#id1363">Overview:</a><a class="headerlink" href="#id548" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.trap</span></tt>‘ intrinsic.</p>
+</div>
+<div class="section" id="id549">
+<h5><a class="toc-backref" href="#id1364">Arguments:</a><a class="headerlink" href="#id549" title="Permalink to this headline">¶</a></h5>
+<p>None.</p>
+</div>
+<div class="section" id="id550">
+<h5><a class="toc-backref" href="#id1365">Semantics:</a><a class="headerlink" href="#id550" title="Permalink to this headline">¶</a></h5>
+<p>This intrinsic is lowered to the target dependent trap instruction. If
+the target does not have a trap instruction, this intrinsic will be
+lowered to a call of the <tt class="docutils literal"><span class="pre">abort()</span></tt> function.</p>
+</div>
+</div>
+<div class="section" id="llvm-debugtrap-intrinsic">
+<h4><a class="toc-backref" href="#id1366">‘<tt class="docutils literal"><span class="pre">llvm.debugtrap</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-debugtrap-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id551">
+<h5><a class="toc-backref" href="#id1367">Syntax:</a><a class="headerlink" href="#id551" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.debugtrap() nounwind
+</pre></div>
+</div>
+</div>
+<div class="section" id="id552">
+<h5><a class="toc-backref" href="#id1368">Overview:</a><a class="headerlink" href="#id552" title="Permalink to this headline">¶</a></h5>
+<p>The ‘<tt class="docutils literal"><span class="pre">llvm.debugtrap</span></tt>‘ intrinsic.</p>
+</div>
+<div class="section" id="id553">
+<h5><a class="toc-backref" href="#id1369">Arguments:</a><a class="headerlink" href="#id553" title="Permalink to this headline">¶</a></h5>
+<p>None.</p>
+</div>
+<div class="section" id="id554">
+<h5><a class="toc-backref" href="#id1370">Semantics:</a><a class="headerlink" href="#id554" title="Permalink to this headline">¶</a></h5>
+<p>This intrinsic is lowered to code which is intended to cause an
+execution trap with the intention of requesting the attention of a
+debugger.</p>
+</div>
+</div>
+<div class="section" id="llvm-stackprotector-intrinsic">
+<h4><a class="toc-backref" href="#id1371">‘<tt class="docutils literal"><span class="pre">llvm.stackprotector</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-stackprotector-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id555">
+<h5><a class="toc-backref" href="#id1372">Syntax:</a><a class="headerlink" href="#id555" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.stackprotector(i8* <guard>, i8** <slot>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id556">
+<h5><a class="toc-backref" href="#id1373">Overview:</a><a class="headerlink" href="#id556" title="Permalink to this headline">¶</a></h5>
+<p>The <tt class="docutils literal"><span class="pre">llvm.stackprotector</span></tt> intrinsic takes the <tt class="docutils literal"><span class="pre">guard</span></tt> and stores it
+onto the stack at <tt class="docutils literal"><span class="pre">slot</span></tt>. The stack slot is adjusted to ensure that it
+is placed on the stack before local variables.</p>
+</div>
+<div class="section" id="id557">
+<h5><a class="toc-backref" href="#id1374">Arguments:</a><a class="headerlink" href="#id557" title="Permalink to this headline">¶</a></h5>
+<p>The <tt class="docutils literal"><span class="pre">llvm.stackprotector</span></tt> intrinsic requires two pointer arguments.
+The first argument is the value loaded from the stack guard
+<tt class="docutils literal"><span class="pre">@__stack_chk_guard</span></tt>. The second variable is an <tt class="docutils literal"><span class="pre">alloca</span></tt> that has
+enough space to hold the value of the guard.</p>
+</div>
+<div class="section" id="id558">
+<h5><a class="toc-backref" href="#id1375">Semantics:</a><a class="headerlink" href="#id558" title="Permalink to this headline">¶</a></h5>
+<p>This intrinsic causes the prologue/epilogue inserter to force the position of
+the <tt class="docutils literal"><span class="pre">AllocaInst</span></tt> stack slot to be before local variables on the stack. This is
+to ensure that if a local variable on the stack is overwritten, it will destroy
+the value of the guard. When the function exits, the guard on the stack is
+checked against the original guard by <tt class="docutils literal"><span class="pre">llvm.stackprotectorcheck</span></tt>. If they are
+different, then <tt class="docutils literal"><span class="pre">llvm.stackprotectorcheck</span></tt> causes the program to abort by
+calling the <tt class="docutils literal"><span class="pre">__stack_chk_fail()</span></tt> function.</p>
+</div>
+</div>
+<div class="section" id="llvm-stackprotectorcheck-intrinsic">
+<h4><a class="toc-backref" href="#id1376">‘<tt class="docutils literal"><span class="pre">llvm.stackprotectorcheck</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-stackprotectorcheck-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id559">
+<h5><a class="toc-backref" href="#id1377">Syntax:</a><a class="headerlink" href="#id559" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.stackprotectorcheck(i8** <guard>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id560">
+<h5><a class="toc-backref" href="#id1378">Overview:</a><a class="headerlink" href="#id560" title="Permalink to this headline">¶</a></h5>
+<p>The <tt class="docutils literal"><span class="pre">llvm.stackprotectorcheck</span></tt> intrinsic compares <tt class="docutils literal"><span class="pre">guard</span></tt> against an already
+created stack protector and if they are not equal calls the
+<tt class="docutils literal"><span class="pre">__stack_chk_fail()</span></tt> function.</p>
+</div>
+<div class="section" id="id561">
+<h5><a class="toc-backref" href="#id1379">Arguments:</a><a class="headerlink" href="#id561" title="Permalink to this headline">¶</a></h5>
+<p>The <tt class="docutils literal"><span class="pre">llvm.stackprotectorcheck</span></tt> intrinsic requires one pointer argument, the
+the variable <tt class="docutils literal"><span class="pre">@__stack_chk_guard</span></tt>.</p>
+</div>
+<div class="section" id="id562">
+<h5><a class="toc-backref" href="#id1380">Semantics:</a><a class="headerlink" href="#id562" title="Permalink to this headline">¶</a></h5>
+<p>This intrinsic is provided to perform the stack protector check by comparing
+<tt class="docutils literal"><span class="pre">guard</span></tt> with the stack slot created by <tt class="docutils literal"><span class="pre">llvm.stackprotector</span></tt> and if the
+values do not match call the <tt class="docutils literal"><span class="pre">__stack_chk_fail()</span></tt> function.</p>
+<p>The reason to provide this as an IR level intrinsic instead of implementing it
+via other IR operations is that in order to perform this operation at the IR
+level without an intrinsic, one would need to create additional basic blocks to
+handle the success/failure cases. This makes it difficult to stop the stack
+protector check from disrupting sibling tail calls in Codegen. With this
+intrinsic, we are able to generate the stack protector basic blocks late in
+codegen after the tail call decision has occurred.</p>
+</div>
+</div>
+<div class="section" id="llvm-objectsize-intrinsic">
+<h4><a class="toc-backref" href="#id1381">‘<tt class="docutils literal"><span class="pre">llvm.objectsize</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-objectsize-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id563">
+<h5><a class="toc-backref" href="#id1382">Syntax:</a><a class="headerlink" href="#id563" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare i32 @llvm.objectsize.i32(i8* <object>, i1 <min>)
+declare i64 @llvm.objectsize.i64(i8* <object>, i1 <min>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id564">
+<h5><a class="toc-backref" href="#id1383">Overview:</a><a class="headerlink" href="#id564" title="Permalink to this headline">¶</a></h5>
+<p>The <tt class="docutils literal"><span class="pre">llvm.objectsize</span></tt> intrinsic is designed to provide information to
+the optimizers to determine at compile time whether a) an operation
+(like memcpy) will overflow a buffer that corresponds to an object, or
+b) that a runtime check for overflow isn’t necessary. An object in this
+context means an allocation of a specific class, structure, array, or
+other object.</p>
+</div>
+<div class="section" id="id565">
+<h5><a class="toc-backref" href="#id1384">Arguments:</a><a class="headerlink" href="#id565" title="Permalink to this headline">¶</a></h5>
+<p>The <tt class="docutils literal"><span class="pre">llvm.objectsize</span></tt> intrinsic takes two arguments. The first
+argument is a pointer to or into the <tt class="docutils literal"><span class="pre">object</span></tt>. The second argument is
+a boolean and determines whether <tt class="docutils literal"><span class="pre">llvm.objectsize</span></tt> returns 0 (if true)
+or -1 (if false) when the object size is unknown. The second argument
+only accepts constants.</p>
+</div>
+<div class="section" id="id566">
+<h5><a class="toc-backref" href="#id1385">Semantics:</a><a class="headerlink" href="#id566" title="Permalink to this headline">¶</a></h5>
+<p>The <tt class="docutils literal"><span class="pre">llvm.objectsize</span></tt> intrinsic is lowered to a constant representing
+the size of the object concerned. If the size cannot be determined at
+compile time, <tt class="docutils literal"><span class="pre">llvm.objectsize</span></tt> returns <tt class="docutils literal"><span class="pre">i32/i64</span> <span class="pre">-1</span> <span class="pre">or</span> <span class="pre">0</span></tt> (depending
+on the <tt class="docutils literal"><span class="pre">min</span></tt> argument).</p>
+</div>
+</div>
+<div class="section" id="llvm-expect-intrinsic">
+<h4><a class="toc-backref" href="#id1386">‘<tt class="docutils literal"><span class="pre">llvm.expect</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-expect-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id567">
+<h5><a class="toc-backref" href="#id1387">Syntax:</a><a class="headerlink" href="#id567" title="Permalink to this headline">¶</a></h5>
+<p>This is an overloaded intrinsic. You can use <tt class="docutils literal"><span class="pre">llvm.expect</span></tt> on any
+integer bit width.</p>
+<div class="highlight-python"><div class="highlight"><pre>declare i1 @llvm.expect.i1(i1 <val>, i1 <expected_val>)
+declare i32 @llvm.expect.i32(i32 <val>, i32 <expected_val>)
+declare i64 @llvm.expect.i64(i64 <val>, i64 <expected_val>)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id568">
+<h5><a class="toc-backref" href="#id1388">Overview:</a><a class="headerlink" href="#id568" title="Permalink to this headline">¶</a></h5>
+<p>The <tt class="docutils literal"><span class="pre">llvm.expect</span></tt> intrinsic provides information about expected (the
+most probable) value of <tt class="docutils literal"><span class="pre">val</span></tt>, which can be used by optimizers.</p>
+</div>
+<div class="section" id="id569">
+<h5><a class="toc-backref" href="#id1389">Arguments:</a><a class="headerlink" href="#id569" title="Permalink to this headline">¶</a></h5>
+<p>The <tt class="docutils literal"><span class="pre">llvm.expect</span></tt> intrinsic takes two arguments. The first argument is
+a value. The second argument is an expected value, this needs to be a
+constant value, variables are not allowed.</p>
+</div>
+<div class="section" id="id570">
+<h5><a class="toc-backref" href="#id1390">Semantics:</a><a class="headerlink" href="#id570" title="Permalink to this headline">¶</a></h5>
+<p>This intrinsic is lowered to the <tt class="docutils literal"><span class="pre">val</span></tt>.</p>
+</div>
+</div>
+<div class="section" id="llvm-assume-intrinsic">
+<h4><a class="toc-backref" href="#id1391">‘<tt class="docutils literal"><span class="pre">llvm.assume</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-assume-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id571">
+<h5><a class="toc-backref" href="#id1392">Syntax:</a><a class="headerlink" href="#id571" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.assume(i1 %cond)
+</pre></div>
+</div>
+</div>
+<div class="section" id="id572">
+<h5><a class="toc-backref" href="#id1393">Overview:</a><a class="headerlink" href="#id572" title="Permalink to this headline">¶</a></h5>
+<p>The <tt class="docutils literal"><span class="pre">llvm.assume</span></tt> allows the optimizer to assume that the provided
+condition is true. This information can then be used in simplifying other parts
+of the code.</p>
+</div>
+<div class="section" id="id573">
+<h5><a class="toc-backref" href="#id1394">Arguments:</a><a class="headerlink" href="#id573" title="Permalink to this headline">¶</a></h5>
+<p>The condition which the optimizer may assume is always true.</p>
+</div>
+<div class="section" id="id574">
+<h5><a class="toc-backref" href="#id1395">Semantics:</a><a class="headerlink" href="#id574" title="Permalink to this headline">¶</a></h5>
+<p>The intrinsic allows the optimizer to assume that the provided condition is
+always true whenever the control flow reaches the intrinsic call. No code is
+generated for this intrinsic, and instructions that contribute only to the
+provided condition are not used for code generation. If the condition is
+violated during execution, the behavior is undefined.</p>
+<p>Note that the optimizer might limit the transformations performed on values
+used by the <tt class="docutils literal"><span class="pre">llvm.assume</span></tt> intrinsic in order to preserve the instructions
+only used to form the intrinsic’s input argument. This might prove undesirable
+if the extra information provided by the <tt class="docutils literal"><span class="pre">llvm.assume</span></tt> intrinsic does not cause
+sufficient overall improvement in code quality. For this reason,
+<tt class="docutils literal"><span class="pre">llvm.assume</span></tt> should not be used to document basic mathematical invariants
+that the optimizer can otherwise deduce or facts that are of little use to the
+optimizer.</p>
+</div>
+</div>
+<div class="section" id="llvm-donothing-intrinsic">
+<h4><a class="toc-backref" href="#id1396">‘<tt class="docutils literal"><span class="pre">llvm.donothing</span></tt>‘ Intrinsic</a><a class="headerlink" href="#llvm-donothing-intrinsic" title="Permalink to this headline">¶</a></h4>
+<div class="section" id="id575">
+<h5><a class="toc-backref" href="#id1397">Syntax:</a><a class="headerlink" href="#id575" title="Permalink to this headline">¶</a></h5>
+<div class="highlight-python"><div class="highlight"><pre>declare void @llvm.donothing() nounwind readnone
+</pre></div>
+</div>
+</div>
+<div class="section" id="id576">
+<h5><a class="toc-backref" href="#id1398">Overview:</a><a class="headerlink" href="#id576" title="Permalink to this headline">¶</a></h5>
+<p>The <tt class="docutils literal"><span class="pre">llvm.donothing</span></tt> intrinsic doesn’t perform any operation. It’s one of only
+two intrinsics (besides <tt class="docutils literal"><span class="pre">llvm.experimental.patchpoint</span></tt>) that can be called
+with an invoke instruction.</p>
+</div>
+<div class="section" id="id577">
+<h5><a class="toc-backref" href="#id1399">Arguments:</a><a class="headerlink" href="#id577" title="Permalink to this headline">¶</a></h5>
+<p>None.</p>
+</div>
+<div class="section" id="id578">
+<h5><a class="toc-backref" href="#id1400">Semantics:</a><a class="headerlink" href="#id578" title="Permalink to this headline">¶</a></h5>
+<p>This intrinsic does nothing, and it’s removed by optimizers and ignored
+by codegen.</p>
+</div>
+</div>
+</div>
+<div class="section" id="stack-map-intrinsics">
+<h3><a class="toc-backref" href="#id1401">Stack Map Intrinsics</a><a class="headerlink" href="#stack-map-intrinsics" title="Permalink to this headline">¶</a></h3>
+<p>LLVM provides experimental intrinsics to support runtime patching
+mechanisms commonly desired in dynamic language JITs. These intrinsics
+are described in <a class="reference internal" href="StackMaps.html"><em>Stack maps and patch points in LLVM</em></a>.</p>
+</div>
+</div>
+</div>
+
+
+          </div>
+      </div>
+      <div class="clearer"></div>
+    </div>
+    <div class="related">
+      <h3>Navigation</h3>
+      <ul>
+        <li class="right" style="margin-right: 10px">
+          <a href="genindex.html" title="General Index"
+             >index</a></li>
+        <li class="right" >
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+      Last updated on 2015-01-21.
+      Created using <a href="http://sphinx-doc.org/">Sphinx</a> 1.2.2.
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+</html>
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==============================================================================
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+
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+    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
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+    <title>The LLVM Lexicon — LLVM 3.6 documentation</title>
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+    <link rel="top" title="LLVM 3.6 documentation" href="index.html" />
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+<style type="text/css">
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+</style>
+
+  </head>
+  <body>
+<div class="logo">
+  <a href="index.html">
+    <img src="_static/logo.png"
+         alt="LLVM Logo" width="250" height="88"/></a>
+</div>
+
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+      <h3>Navigation</h3>
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+        <li class="right" style="margin-right: 10px">
+          <a href="genindex.html" title="General Index"
+             accesskey="I">index</a></li>
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+             accesskey="P">previous</a> |</li>
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+ 
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+    </div>
+
+
+    <div class="document">
+      <div class="documentwrapper">
+          <div class="body">
+            
+  <div class="section" id="the-llvm-lexicon">
+<h1>The LLVM Lexicon<a class="headerlink" href="#the-llvm-lexicon" title="Permalink to this headline">¶</a></h1>
+<div class="admonition note">
+<p class="first admonition-title">Note</p>
+<p class="last">This document is a work in progress!</p>
+</div>
+<div class="section" id="definitions">
+<h2>Definitions<a class="headerlink" href="#definitions" title="Permalink to this headline">¶</a></h2>
+<div class="section" id="a">
+<h3>A<a class="headerlink" href="#a" title="Permalink to this headline">¶</a></h3>
+<dl class="docutils">
+<dt><strong>ADCE</strong></dt>
+<dd>Aggressive Dead Code Elimination</dd>
+<dt><strong>AST</strong></dt>
+<dd><p class="first">Abstract Syntax Tree.</p>
+<p>Due to Clang’s influence (mostly the fact that parsing and semantic
+analysis are so intertwined for C and especially C++), the typical
+working definition of AST in the LLVM community is roughly “the
+compiler’s first complete symbolic (as opposed to textual)
+representation of an input program”.
+As such, an “AST” might be a more general graph instead of a “tree”
+(consider the symbolic representation for the type of a typical “linked
+list node”). This working definition is closer to what some authors
+call an “annotated abstract syntax tree”.</p>
+<p class="last">Consult your favorite compiler book or search engine for more details.</p>
+</dd>
+</dl>
+</div>
+<div class="section" id="b">
+<h3>B<a class="headerlink" href="#b" title="Permalink to this headline">¶</a></h3>
+<dl class="docutils" id="lexicon-bb-vectorization">
+<dt><strong>BB Vectorization</strong></dt>
+<dd>Basic-Block Vectorization</dd>
+<dt><strong>BURS</strong></dt>
+<dd>Bottom Up Rewriting System — A method of instruction selection for code
+generation.  An example is the <a class="reference external" href="http://www.program-transformation.org/Transform/BURG">BURG</a> tool.</dd>
+</dl>
+</div>
+<div class="section" id="c">
+<h3>C<a class="headerlink" href="#c" title="Permalink to this headline">¶</a></h3>
+<dl class="docutils">
+<dt><strong>CSE</strong></dt>
+<dd>Common Subexpression Elimination. An optimization that removes common
+subexpression compuation. For example <tt class="docutils literal"><span class="pre">(a+b)*(a+b)</span></tt> has two subexpressions
+that are the same: <tt class="docutils literal"><span class="pre">(a+b)</span></tt>. This optimization would perform the addition
+only once and then perform the multiply (but only if it’s computationally
+correct/safe).</dd>
+</dl>
+</div>
+<div class="section" id="d">
+<h3>D<a class="headerlink" href="#d" title="Permalink to this headline">¶</a></h3>
+<dl class="docutils">
+<dt><strong>DAG</strong></dt>
+<dd>Directed Acyclic Graph</dd>
+</dl>
+<dl class="docutils" id="derived-pointers">
+<span id="derived-pointer"></span><dt><strong>Derived Pointer</strong></dt>
+<dd>A pointer to the interior of an object, such that a garbage collector is
+unable to use the pointer for reachability analysis. While a derived pointer
+is live, the corresponding object pointer must be kept in a root, otherwise
+the collector might free the referenced object. With copying collectors,
+derived pointers pose an additional hazard that they may be invalidated at
+any <a class="reference internal" href="#safe-point">safe point</a>. This term is used in opposition to <a class="reference internal" href="#object-pointer">object pointer</a>.</dd>
+<dt><strong>DSA</strong></dt>
+<dd>Data Structure Analysis</dd>
+<dt><strong>DSE</strong></dt>
+<dd>Dead Store Elimination</dd>
+</dl>
+</div>
+<div class="section" id="f">
+<h3>F<a class="headerlink" href="#f" title="Permalink to this headline">¶</a></h3>
+<dl class="docutils">
+<dt><strong>FCA</strong></dt>
+<dd>First Class Aggregate</dd>
+</dl>
+</div>
+<div class="section" id="g">
+<h3>G<a class="headerlink" href="#g" title="Permalink to this headline">¶</a></h3>
+<dl class="docutils">
+<dt><strong>GC</strong></dt>
+<dd>Garbage Collection. The practice of using reachability analysis instead of
+explicit memory management to reclaim unused memory.</dd>
+</dl>
+</div>
+<div class="section" id="h">
+<h3>H<a class="headerlink" href="#h" title="Permalink to this headline">¶</a></h3>
+<dl class="docutils" id="heap">
+<dt><strong>Heap</strong></dt>
+<dd>In garbage collection, the region of memory which is managed using
+reachability analysis.</dd>
+</dl>
+</div>
+<div class="section" id="i">
+<h3>I<a class="headerlink" href="#i" title="Permalink to this headline">¶</a></h3>
+<dl class="docutils">
+<dt><strong>IPA</strong></dt>
+<dd>Inter-Procedural Analysis. Refers to any variety of code analysis that
+occurs between procedures, functions or compilation units (modules).</dd>
+<dt><strong>IPO</strong></dt>
+<dd>Inter-Procedural Optimization. Refers to any variety of code optimization
+that occurs between procedures, functions or compilation units (modules).</dd>
+<dt><strong>ISel</strong></dt>
+<dd>Instruction Selection</dd>
+</dl>
+</div>
+<div class="section" id="l">
+<h3>L<a class="headerlink" href="#l" title="Permalink to this headline">¶</a></h3>
+<dl class="docutils">
+<dt><strong>LCSSA</strong></dt>
+<dd>Loop-Closed Static Single Assignment Form</dd>
+<dt><strong>LICM</strong></dt>
+<dd>Loop Invariant Code Motion</dd>
+<dt><strong>Load-VN</strong></dt>
+<dd>Load Value Numbering</dd>
+<dt><strong>LTO</strong></dt>
+<dd>Link-Time Optimization</dd>
+</dl>
+</div>
+<div class="section" id="m">
+<h3>M<a class="headerlink" href="#m" title="Permalink to this headline">¶</a></h3>
+<dl class="docutils">
+<dt><strong>MC</strong></dt>
+<dd>Machine Code</dd>
+</dl>
+</div>
+<div class="section" id="n">
+<h3>N<a class="headerlink" href="#n" title="Permalink to this headline">¶</a></h3>
+<dl class="docutils">
+<dt><strong>NFC</strong></dt>
+<dd>“No functional change”. Used in a commit message to indicate that a patch
+is a pure refactoring/cleanup.
+Usually used in the first line, so it is visible without opening the
+actual commit email.</dd>
+</dl>
+</div>
+<div class="section" id="o">
+<h3>O<a class="headerlink" href="#o" title="Permalink to this headline">¶</a></h3>
+<dl class="docutils" id="object-pointers">
+<span id="object-pointer"></span><dt><strong>Object Pointer</strong></dt>
+<dd>A pointer to an object such that the garbage collector is able to trace
+references contained within the object. This term is used in opposition to
+<a class="reference internal" href="#derived-pointer">derived pointer</a>.</dd>
+</dl>
+</div>
+<div class="section" id="p">
+<h3>P<a class="headerlink" href="#p" title="Permalink to this headline">¶</a></h3>
+<dl class="docutils">
+<dt><strong>PRE</strong></dt>
+<dd>Partial Redundancy Elimination</dd>
+</dl>
+</div>
+<div class="section" id="r">
+<h3>R<a class="headerlink" href="#r" title="Permalink to this headline">¶</a></h3>
+<p><strong>RAUW</strong></p>
+<blockquote>
+<div>Replace All Uses With. The functions <tt class="docutils literal"><span class="pre">User::replaceUsesOfWith()</span></tt>,
+<tt class="docutils literal"><span class="pre">Value::replaceAllUsesWith()</span></tt>, and
+<tt class="docutils literal"><span class="pre">Constant::replaceUsesOfWithOnConstant()</span></tt> implement the replacement of one
+Value with another by iterating over its def/use chain and fixing up all of
+the pointers to point to the new value.  See
+also <a class="reference external" href="ProgrammersManual.html#iterating-over-def-use-use-def-chains">def/use chains</a>.</div></blockquote>
+<dl class="docutils">
+<dt><strong>Reassociation</strong></dt>
+<dd>Rearranging associative expressions to promote better redundancy elimination
+and other optimization.  For example, changing <tt class="docutils literal"><span class="pre">(A+B-A)</span></tt> into <tt class="docutils literal"><span class="pre">(B+A-A)</span></tt>,
+permitting it to be optimized into <tt class="docutils literal"><span class="pre">(B+0)</span></tt> then <tt class="docutils literal"><span class="pre">(B)</span></tt>.</dd>
+</dl>
+<dl class="docutils" id="stack-roots">
+<span id="roots"></span><dt><strong>Root</strong></dt>
+<dd>In garbage collection, a pointer variable lying outside of the <a class="reference internal" href="#heap">heap</a> from
+which the collector begins its reachability analysis. In the context of code
+generation, “root” almost always refers to a “stack root” — a local or
+temporary variable within an executing function.</dd>
+<dt><strong>RPO</strong></dt>
+<dd>Reverse postorder</dd>
+</dl>
+</div>
+<div class="section" id="s">
+<h3>S<a class="headerlink" href="#s" title="Permalink to this headline">¶</a></h3>
+<dl class="docutils" id="safe-point">
+<dt><strong>Safe Point</strong></dt>
+<dd>In garbage collection, it is necessary to identify <a class="reference internal" href="#stack-roots">stack roots</a> so that
+reachability analysis may proceed. It may be infeasible to provide this
+information for every instruction, so instead the information may is
+calculated only at designated safe points. With a copying collector,
+<a class="reference internal" href="#derived-pointers">derived pointers</a> must not be retained across safe points and <a class="reference internal" href="#object-pointers">object
+pointers</a> must be reloaded from stack roots.</dd>
+<dt><strong>SDISel</strong></dt>
+<dd>Selection DAG Instruction Selection.</dd>
+<dt><strong>SCC</strong></dt>
+<dd>Strongly Connected Component</dd>
+<dt><strong>SCCP</strong></dt>
+<dd>Sparse Conditional Constant Propagation</dd>
+<dt><strong>SLP</strong></dt>
+<dd>Superword-Level Parallelism, same as <a class="reference internal" href="#lexicon-bb-vectorization"><em>Basic-Block Vectorization</em></a>.</dd>
+<dt><strong>SRoA</strong></dt>
+<dd>Scalar Replacement of Aggregates</dd>
+<dt><strong>SSA</strong></dt>
+<dd>Static Single Assignment</dd>
+<dt><strong>Stack Map</strong></dt>
+<dd>In garbage collection, metadata emitted by the code generator which
+identifies <a class="reference internal" href="#roots">roots</a> within the stack frame of an executing function.</dd>
+</dl>
+</div>
+<div class="section" id="t">
+<h3>T<a class="headerlink" href="#t" title="Permalink to this headline">¶</a></h3>
+<dl class="docutils">
+<dt><strong>TBAA</strong></dt>
+<dd>Type-Based Alias Analysis</dd>
+</dl>
+</div>
+</div>
+</div>
+
+
+          </div>
+      </div>
+      <div class="clearer"></div>
+    </div>
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+      <h3>Navigation</h3>
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+        <li class="right" style="margin-right: 10px">
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+      Last updated on 2015-01-21.
+      Created using <a href="http://sphinx-doc.org/">Sphinx</a> 1.2.2.
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Added: www-releases/trunk/3.6.0/docs/LinkTimeOptimization.html
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+++ www-releases/trunk/3.6.0/docs/LinkTimeOptimization.html Fri Feb 27 12:44:09 2015
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+  <div class="section" id="llvm-link-time-optimization-design-and-implementation">
+<h1>LLVM Link Time Optimization: Design and Implementation<a class="headerlink" href="#llvm-link-time-optimization-design-and-implementation" title="Permalink to this headline">¶</a></h1>
+<div class="contents local topic" id="contents">
+<ul class="simple">
+<li><a class="reference internal" href="#description" id="id2">Description</a></li>
+<li><a class="reference internal" href="#design-philosophy" id="id3">Design Philosophy</a><ul>
+<li><a class="reference internal" href="#example-of-link-time-optimization" id="id4">Example of link time optimization</a></li>
+<li><a class="reference internal" href="#alternative-approaches" id="id5">Alternative Approaches</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#multi-phase-communication-between-liblto-and-linker" id="id6">Multi-phase communication between <tt class="docutils literal"><span class="pre">libLTO</span></tt> and linker</a><ul>
+<li><a class="reference internal" href="#phase-1-read-llvm-bitcode-files" id="id7">Phase 1 : Read LLVM Bitcode Files</a></li>
+<li><a class="reference internal" href="#phase-2-symbol-resolution" id="id8">Phase 2 : Symbol Resolution</a></li>
+<li><a class="reference internal" href="#phase-3-optimize-bitcode-files" id="id9">Phase 3 : Optimize Bitcode Files</a></li>
+<li><a class="reference internal" href="#phase-4-symbol-resolution-after-optimization" id="id10">Phase 4 : Symbol Resolution after optimization</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#liblto" id="id11"><tt class="docutils literal"><span class="pre">libLTO</span></tt></a><ul>
+<li><a class="reference internal" href="#lto-module-t" id="id12"><tt class="docutils literal"><span class="pre">lto_module_t</span></tt></a></li>
+<li><a class="reference internal" href="#lto-code-gen-t" id="id13"><tt class="docutils literal"><span class="pre">lto_code_gen_t</span></tt></a></li>
+</ul>
+</li>
+</ul>
+</div>
+<div class="section" id="description">
+<h2><a class="toc-backref" href="#id2">Description</a><a class="headerlink" href="#description" title="Permalink to this headline">¶</a></h2>
+<p>LLVM features powerful intermodular optimizations which can be used at link
+time.  Link Time Optimization (LTO) is another name for intermodular
+optimization when performed during the link stage. This document describes the
+interface and design between the LTO optimizer and the linker.</p>
+</div>
+<div class="section" id="design-philosophy">
+<h2><a class="toc-backref" href="#id3">Design Philosophy</a><a class="headerlink" href="#design-philosophy" title="Permalink to this headline">¶</a></h2>
+<p>The LLVM Link Time Optimizer provides complete transparency, while doing
+intermodular optimization, in the compiler tool chain. Its main goal is to let
+the developer take advantage of intermodular optimizations without making any
+significant changes to the developer’s makefiles or build system. This is
+achieved through tight integration with the linker. In this model, the linker
+treates LLVM bitcode files like native object files and allows mixing and
+matching among them. The linker uses <a class="reference internal" href="#liblto">libLTO</a>, a shared object, to handle LLVM
+bitcode files. This tight integration between the linker and LLVM optimizer
+helps to do optimizations that are not possible in other models. The linker
+input allows the optimizer to avoid relying on conservative escape analysis.</p>
+<div class="section" id="example-of-link-time-optimization">
+<span id="liblto-example"></span><h3><a class="toc-backref" href="#id4">Example of link time optimization</a><a class="headerlink" href="#example-of-link-time-optimization" title="Permalink to this headline">¶</a></h3>
+<p>The following example illustrates the advantages of LTO’s integrated approach
+and clean interface. This example requires a system linker which supports LTO
+through the interface described in this document.  Here, clang transparently
+invokes system linker.</p>
+<ul class="simple">
+<li>Input source file <tt class="docutils literal"><span class="pre">a.c</span></tt> is compiled into LLVM bitcode form.</li>
+<li>Input source file <tt class="docutils literal"><span class="pre">main.c</span></tt> is compiled into native object code.</li>
+</ul>
+<div class="highlight-c++"><div class="highlight"><pre><span class="o">---</span> <span class="n">a</span><span class="p">.</span><span class="n">h</span> <span class="o">---</span>
+<span class="k">extern</span> <span class="kt">int</span> <span class="n">foo1</span><span class="p">(</span><span class="kt">void</span><span class="p">);</span>
+<span class="k">extern</span> <span class="kt">void</span> <span class="nf">foo2</span><span class="p">(</span><span class="kt">void</span><span class="p">);</span>
+<span class="k">extern</span> <span class="kt">void</span> <span class="nf">foo4</span><span class="p">(</span><span class="kt">void</span><span class="p">);</span>
+
+<span class="o">---</span> <span class="n">a</span><span class="p">.</span><span class="n">c</span> <span class="o">---</span>
+<span class="cp">#include "a.h"</span>
+
+<span class="k">static</span> <span class="kt">signed</span> <span class="kt">int</span> <span class="n">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
+
+<span class="kt">void</span> <span class="nf">foo2</span><span class="p">(</span><span class="kt">void</span><span class="p">)</span> <span class="p">{</span>
+  <span class="n">i</span> <span class="o">=</span> <span class="o">-</span><span class="mi">1</span><span class="p">;</span>
+<span class="p">}</span>
+
+<span class="k">static</span> <span class="kt">int</span> <span class="nf">foo3</span><span class="p">()</span> <span class="p">{</span>
+  <span class="n">foo4</span><span class="p">();</span>
+  <span class="k">return</span> <span class="mi">10</span><span class="p">;</span>
+<span class="p">}</span>
+
+<span class="kt">int</span> <span class="nf">foo1</span><span class="p">(</span><span class="kt">void</span><span class="p">)</span> <span class="p">{</span>
+  <span class="kt">int</span> <span class="n">data</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
+
+  <span class="k">if</span> <span class="p">(</span><span class="n">i</span> <span class="o"><</span> <span class="mi">0</span><span class="p">)</span>
+    <span class="n">data</span> <span class="o">=</span> <span class="n">foo3</span><span class="p">();</span>
+
+  <span class="n">data</span> <span class="o">=</span> <span class="n">data</span> <span class="o">+</span> <span class="mi">42</span><span class="p">;</span>
+  <span class="k">return</span> <span class="n">data</span><span class="p">;</span>
+<span class="p">}</span>
+
+<span class="o">---</span> <span class="n">main</span><span class="p">.</span><span class="n">c</span> <span class="o">---</span>
+<span class="cp">#include <stdio.h></span>
+<span class="cp">#include "a.h"</span>
+
+<span class="kt">void</span> <span class="n">foo4</span><span class="p">(</span><span class="kt">void</span><span class="p">)</span> <span class="p">{</span>
+  <span class="n">printf</span><span class="p">(</span><span class="s">"Hi</span><span class="se">\n</span><span class="s">"</span><span class="p">);</span>
+<span class="p">}</span>
+
+<span class="kt">int</span> <span class="n">main</span><span class="p">()</span> <span class="p">{</span>
+  <span class="k">return</span> <span class="n">foo1</span><span class="p">();</span>
+<span class="p">}</span>
+</pre></div>
+</div>
+<p>To compile, run:</p>
+<div class="highlight-console"><div class="highlight"><pre><span class="gp">%</span> clang -emit-llvm -c a.c -o a.o   <span class="c"># <-- a.o is LLVM bitcode file</span>
+<span class="gp">%</span> clang -c main.c -o main.o        <span class="c"># <-- main.o is native object file</span>
+<span class="gp">%</span> clang a.o main.o -o main         <span class="c"># <-- standard link command without modifications</span>
+</pre></div>
+</div>
+<ul class="simple">
+<li>In this example, the linker recognizes that <tt class="docutils literal"><span class="pre">foo2()</span></tt> is an externally
+visible symbol defined in LLVM bitcode file. The linker completes its usual
+symbol resolution pass and finds that <tt class="docutils literal"><span class="pre">foo2()</span></tt> is not used
+anywhere. This information is used by the LLVM optimizer and it
+removes <tt class="docutils literal"><span class="pre">foo2()</span></tt>.</li>
+<li>As soon as <tt class="docutils literal"><span class="pre">foo2()</span></tt> is removed, the optimizer recognizes that condition <tt class="docutils literal"><span class="pre">i</span>
+<span class="pre"><</span> <span class="pre">0</span></tt> is always false, which means <tt class="docutils literal"><span class="pre">foo3()</span></tt> is never used. Hence, the
+optimizer also removes <tt class="docutils literal"><span class="pre">foo3()</span></tt>.</li>
+<li>And this in turn, enables linker to remove <tt class="docutils literal"><span class="pre">foo4()</span></tt>.</li>
+</ul>
+<p>This example illustrates the advantage of tight integration with the
+linker. Here, the optimizer can not remove <tt class="docutils literal"><span class="pre">foo3()</span></tt> without the linker’s
+input.</p>
+</div>
+<div class="section" id="alternative-approaches">
+<h3><a class="toc-backref" href="#id5">Alternative Approaches</a><a class="headerlink" href="#alternative-approaches" title="Permalink to this headline">¶</a></h3>
+<dl class="docutils">
+<dt><strong>Compiler driver invokes link time optimizer separately.</strong></dt>
+<dd>In this model the link time optimizer is not able to take advantage of
+information collected during the linker’s normal symbol resolution phase.
+In the above example, the optimizer can not remove <tt class="docutils literal"><span class="pre">foo2()</span></tt> without the
+linker’s input because it is externally visible. This in turn prohibits the
+optimizer from removing <tt class="docutils literal"><span class="pre">foo3()</span></tt>.</dd>
+<dt><strong>Use separate tool to collect symbol information from all object files.</strong></dt>
+<dd>In this model, a new, separate, tool or library replicates the linker’s
+capability to collect information for link time optimization. Not only is
+this code duplication difficult to justify, but it also has several other
+disadvantages.  For example, the linking semantics and the features provided
+by the linker on various platform are not unique. This means, this new tool
+needs to support all such features and platforms in one super tool or a
+separate tool per platform is required. This increases maintenance cost for
+link time optimizer significantly, which is not necessary. This approach
+also requires staying synchronized with linker developements on various
+platforms, which is not the main focus of the link time optimizer. Finally,
+this approach increases end user’s build time due to the duplication of work
+done by this separate tool and the linker itself.</dd>
+</dl>
+</div>
+</div>
+<div class="section" id="multi-phase-communication-between-liblto-and-linker">
+<h2><a class="toc-backref" href="#id6">Multi-phase communication between <tt class="docutils literal"><span class="pre">libLTO</span></tt> and linker</a><a class="headerlink" href="#multi-phase-communication-between-liblto-and-linker" title="Permalink to this headline">¶</a></h2>
+<p>The linker collects information about symbol definitions and uses in various
+link objects which is more accurate than any information collected by other
+tools during typical build cycles.  The linker collects this information by
+looking at the definitions and uses of symbols in native .o files and using
+symbol visibility information. The linker also uses user-supplied information,
+such as a list of exported symbols. LLVM optimizer collects control flow
+information, data flow information and knows much more about program structure
+from the optimizer’s point of view.  Our goal is to take advantage of tight
+integration between the linker and the optimizer by sharing this information
+during various linking phases.</p>
+<div class="section" id="phase-1-read-llvm-bitcode-files">
+<h3><a class="toc-backref" href="#id7">Phase 1 : Read LLVM Bitcode Files</a><a class="headerlink" href="#phase-1-read-llvm-bitcode-files" title="Permalink to this headline">¶</a></h3>
+<p>The linker first reads all object files in natural order and collects symbol
+information. This includes native object files as well as LLVM bitcode files.
+To minimize the cost to the linker in the case that all .o files are native
+object files, the linker only calls <tt class="docutils literal"><span class="pre">lto_module_create()</span></tt> when a supplied
+object file is found to not be a native object file.  If <tt class="docutils literal"><span class="pre">lto_module_create()</span></tt>
+returns that the file is an LLVM bitcode file, the linker then iterates over the
+module using <tt class="docutils literal"><span class="pre">lto_module_get_symbol_name()</span></tt> and
+<tt class="docutils literal"><span class="pre">lto_module_get_symbol_attribute()</span></tt> to get all symbols defined and referenced.
+This information is added to the linker’s global symbol table.</p>
+<p>The lto* functions are all implemented in a shared object libLTO.  This allows
+the LLVM LTO code to be updated independently of the linker tool.  On platforms
+that support it, the shared object is lazily loaded.</p>
+</div>
+<div class="section" id="phase-2-symbol-resolution">
+<h3><a class="toc-backref" href="#id8">Phase 2 : Symbol Resolution</a><a class="headerlink" href="#phase-2-symbol-resolution" title="Permalink to this headline">¶</a></h3>
+<p>In this stage, the linker resolves symbols using global symbol table.  It may
+report undefined symbol errors, read archive members, replace weak symbols, etc.
+The linker is able to do this seamlessly even though it does not know the exact
+content of input LLVM bitcode files.  If dead code stripping is enabled then the
+linker collects the list of live symbols.</p>
+</div>
+<div class="section" id="phase-3-optimize-bitcode-files">
+<h3><a class="toc-backref" href="#id9">Phase 3 : Optimize Bitcode Files</a><a class="headerlink" href="#phase-3-optimize-bitcode-files" title="Permalink to this headline">¶</a></h3>
+<p>After symbol resolution, the linker tells the LTO shared object which symbols
+are needed by native object files.  In the example above, the linker reports
+that only <tt class="docutils literal"><span class="pre">foo1()</span></tt> is used by native object files using
+<tt class="docutils literal"><span class="pre">lto_codegen_add_must_preserve_symbol()</span></tt>.  Next the linker invokes the LLVM
+optimizer and code generators using <tt class="docutils literal"><span class="pre">lto_codegen_compile()</span></tt> which returns a
+native object file creating by merging the LLVM bitcode files and applying
+various optimization passes.</p>
+</div>
+<div class="section" id="phase-4-symbol-resolution-after-optimization">
+<h3><a class="toc-backref" href="#id10">Phase 4 : Symbol Resolution after optimization</a><a class="headerlink" href="#phase-4-symbol-resolution-after-optimization" title="Permalink to this headline">¶</a></h3>
+<p>In this phase, the linker reads optimized a native object file and updates the
+internal global symbol table to reflect any changes. The linker also collects
+information about any changes in use of external symbols by LLVM bitcode
+files. In the example above, the linker notes that <tt class="docutils literal"><span class="pre">foo4()</span></tt> is not used any
+more. If dead code stripping is enabled then the linker refreshes the live
+symbol information appropriately and performs dead code stripping.</p>
+<p>After this phase, the linker continues linking as if it never saw LLVM bitcode
+files.</p>
+</div>
+</div>
+<div class="section" id="liblto">
+<span id="id1"></span><h2><a class="toc-backref" href="#id11"><tt class="docutils literal"><span class="pre">libLTO</span></tt></a><a class="headerlink" href="#liblto" title="Permalink to this headline">¶</a></h2>
+<p><tt class="docutils literal"><span class="pre">libLTO</span></tt> is a shared object that is part of the LLVM tools, and is intended
+for use by a linker. <tt class="docutils literal"><span class="pre">libLTO</span></tt> provides an abstract C interface to use the LLVM
+interprocedural optimizer without exposing details of LLVM’s internals. The
+intention is to keep the interface as stable as possible even when the LLVM
+optimizer continues to evolve. It should even be possible for a completely
+different compilation technology to provide a different libLTO that works with
+their object files and the standard linker tool.</p>
+<div class="section" id="lto-module-t">
+<h3><a class="toc-backref" href="#id12"><tt class="docutils literal"><span class="pre">lto_module_t</span></tt></a><a class="headerlink" href="#lto-module-t" title="Permalink to this headline">¶</a></h3>
+<p>A non-native object file is handled via an <tt class="docutils literal"><span class="pre">lto_module_t</span></tt>.  The following
+functions allow the linker to check if a file (on disk or in a memory buffer) is
+a file which libLTO can process:</p>
+<div class="highlight-c"><div class="highlight"><pre><span class="n">lto_module_is_object_file</span><span class="p">(</span><span class="k">const</span> <span class="kt">char</span><span class="o">*</span><span class="p">)</span>
+<span class="n">lto_module_is_object_file_for_target</span><span class="p">(</span><span class="k">const</span> <span class="kt">char</span><span class="o">*</span><span class="p">,</span> <span class="k">const</span> <span class="kt">char</span><span class="o">*</span><span class="p">)</span>
+<span class="n">lto_module_is_object_file_in_memory</span><span class="p">(</span><span class="k">const</span> <span class="kt">void</span><span class="o">*</span><span class="p">,</span> <span class="kt">size_t</span><span class="p">)</span>
+<span class="n">lto_module_is_object_file_in_memory_for_target</span><span class="p">(</span><span class="k">const</span> <span class="kt">void</span><span class="o">*</span><span class="p">,</span> <span class="kt">size_t</span><span class="p">,</span> <span class="k">const</span> <span class="kt">char</span><span class="o">*</span><span class="p">)</span>
+</pre></div>
+</div>
+<p>If the object file can be processed by <tt class="docutils literal"><span class="pre">libLTO</span></tt>, the linker creates a
+<tt class="docutils literal"><span class="pre">lto_module_t</span></tt> by using one of:</p>
+<div class="highlight-c"><div class="highlight"><pre><span class="n">lto_module_create</span><span class="p">(</span><span class="k">const</span> <span class="kt">char</span><span class="o">*</span><span class="p">)</span>
+<span class="n">lto_module_create_from_memory</span><span class="p">(</span><span class="k">const</span> <span class="kt">void</span><span class="o">*</span><span class="p">,</span> <span class="kt">size_t</span><span class="p">)</span>
+</pre></div>
+</div>
+<p>and when done, the handle is released via</p>
+<div class="highlight-c"><div class="highlight"><pre><span class="n">lto_module_dispose</span><span class="p">(</span><span class="kt">lto_module_t</span><span class="p">)</span>
+</pre></div>
+</div>
+<p>The linker can introspect the non-native object file by getting the number of
+symbols and getting the name and attributes of each symbol via:</p>
+<div class="highlight-c"><div class="highlight"><pre><span class="n">lto_module_get_num_symbols</span><span class="p">(</span><span class="kt">lto_module_t</span><span class="p">)</span>
+<span class="n">lto_module_get_symbol_name</span><span class="p">(</span><span class="kt">lto_module_t</span><span class="p">,</span> <span class="kt">unsigned</span> <span class="kt">int</span><span class="p">)</span>
+<span class="n">lto_module_get_symbol_attribute</span><span class="p">(</span><span class="kt">lto_module_t</span><span class="p">,</span> <span class="kt">unsigned</span> <span class="kt">int</span><span class="p">)</span>
+</pre></div>
+</div>
+<p>The attributes of a symbol include the alignment, visibility, and kind.</p>
+</div>
+<div class="section" id="lto-code-gen-t">
+<h3><a class="toc-backref" href="#id13"><tt class="docutils literal"><span class="pre">lto_code_gen_t</span></tt></a><a class="headerlink" href="#lto-code-gen-t" title="Permalink to this headline">¶</a></h3>
+<p>Once the linker has loaded each non-native object files into an
+<tt class="docutils literal"><span class="pre">lto_module_t</span></tt>, it can request <tt class="docutils literal"><span class="pre">libLTO</span></tt> to process them all and generate a
+native object file.  This is done in a couple of steps.  First, a code generator
+is created with:</p>
+<div class="highlight-c"><div class="highlight"><pre><span class="n">lto_codegen_create</span><span class="p">()</span>
+</pre></div>
+</div>
+<p>Then, each non-native object file is added to the code generator with:</p>
+<div class="highlight-c"><div class="highlight"><pre><span class="n">lto_codegen_add_module</span><span class="p">(</span><span class="kt">lto_code_gen_t</span><span class="p">,</span> <span class="kt">lto_module_t</span><span class="p">)</span>
+</pre></div>
+</div>
+<p>The linker then has the option of setting some codegen options.  Whether or not
+to generate DWARF debug info is set with:</p>
+<div class="highlight-c"><div class="highlight"><pre><span class="n">lto_codegen_set_debug_model</span><span class="p">(</span><span class="kt">lto_code_gen_t</span><span class="p">)</span>
+</pre></div>
+</div>
+<p>Which kind of position independence is set with:</p>
+<div class="highlight-c"><div class="highlight"><pre><span class="n">lto_codegen_set_pic_model</span><span class="p">(</span><span class="kt">lto_code_gen_t</span><span class="p">)</span>
+</pre></div>
+</div>
+<p>And each symbol that is referenced by a native object file or otherwise must not
+be optimized away is set with:</p>
+<div class="highlight-c"><div class="highlight"><pre><span class="n">lto_codegen_add_must_preserve_symbol</span><span class="p">(</span><span class="kt">lto_code_gen_t</span><span class="p">,</span> <span class="k">const</span> <span class="kt">char</span><span class="o">*</span><span class="p">)</span>
+</pre></div>
+</div>
+<p>After all these settings are done, the linker requests that a native object file
+be created from the modules with the settings using:</p>
+<div class="highlight-c"><div class="highlight"><pre><span class="n">lto_codegen_compile</span><span class="p">(</span><span class="kt">lto_code_gen_t</span><span class="p">,</span> <span class="n">size</span><span class="o">*</span><span class="p">)</span>
+</pre></div>
+</div>
+<p>which returns a pointer to a buffer containing the generated native object file.
+The linker then parses that and links it with the rest of the native object
+files.</p>
+</div>
+</div>
+</div>
+
+
+          </div>
+      </div>
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+  <div class="section" id="mcjit-design-and-implementation">
+<h1>MCJIT Design and Implementation<a class="headerlink" href="#mcjit-design-and-implementation" title="Permalink to this headline">¶</a></h1>
+<div class="section" id="introduction">
+<h2>Introduction<a class="headerlink" href="#introduction" title="Permalink to this headline">¶</a></h2>
+<p>This document describes the internal workings of the MCJIT execution
+engine and the RuntimeDyld component.  It is intended as a high level
+overview of the implementation, showing the flow and interactions of
+objects throughout the code generation and dynamic loading process.</p>
+</div>
+<div class="section" id="engine-creation">
+<h2>Engine Creation<a class="headerlink" href="#engine-creation" title="Permalink to this headline">¶</a></h2>
+<p>In most cases, an EngineBuilder object is used to create an instance of
+the MCJIT execution engine.  The EngineBuilder takes an llvm::Module
+object as an argument to its constructor.  The client may then set various
+options that we control the later be passed along to the MCJIT engine,
+including the selection of MCJIT as the engine type to be created.
+Of particular interest is the EngineBuilder::setMCJITMemoryManager
+function.  If the client does not explicitly create a memory manager at
+this time, a default memory manager (specifically SectionMemoryManager)
+will be created when the MCJIT engine is instantiated.</p>
+<p>Once the options have been set, a client calls EngineBuilder::create to
+create an instance of the MCJIT engine.  If the client does not use the
+form of this function that takes a TargetMachine as a parameter, a new
+TargetMachine will be created based on the target triple associated with
+the Module that was used to create the EngineBuilder.</p>
+<img alt="_images/MCJIT-engine-builder.png" src="_images/MCJIT-engine-builder.png" />
+<p>EngineBuilder::create will call the static MCJIT::createJIT function,
+passing in its pointers to the module, memory manager and target machine
+objects, all of which will subsequently be owned by the MCJIT object.</p>
+<p>The MCJIT class has a member variable, Dyld, which contains an instance of
+the RuntimeDyld wrapper class.  This member will be used for
+communications between MCJIT and the actual RuntimeDyldImpl object that
+gets created when an object is loaded.</p>
+<img alt="_images/MCJIT-creation.png" src="_images/MCJIT-creation.png" />
+<p>Upon creation, MCJIT holds a pointer to the Module object that it received
+from EngineBuilder but it does not immediately generate code for this
+module.  Code generation is deferred until either the
+MCJIT::finalizeObject method is called explicitly or a function such as
+MCJIT::getPointerToFunction is called which requires the code to have been
+generated.</p>
+</div>
+<div class="section" id="code-generation">
+<h2>Code Generation<a class="headerlink" href="#code-generation" title="Permalink to this headline">¶</a></h2>
+<p>When code generation is triggered, as described above, MCJIT will first
+attempt to retrieve an object image from its ObjectCache member, if one
+has been set.  If a cached object image cannot be retrieved, MCJIT will
+call its emitObject method.  MCJIT::emitObject uses a local PassManager
+instance and creates a new ObjectBufferStream instance, both of which it
+passes to TargetMachine::addPassesToEmitMC before calling PassManager::run
+on the Module with which it was created.</p>
+<img alt="_images/MCJIT-load.png" src="_images/MCJIT-load.png" />
+<p>The PassManager::run call causes the MC code generation mechanisms to emit
+a complete relocatable binary object image (either in either ELF or MachO
+format, depending on the target) into the ObjectBufferStream object, which
+is flushed to complete the process.  If an ObjectCache is being used, the
+image will be passed to the ObjectCache here.</p>
+<p>At this point, the ObjectBufferStream contains the raw object image.
+Before the code can be executed, the code and data sections from this
+image must be loaded into suitable memory, relocations must be applied and
+memory permission and code cache invalidation (if required) must be completed.</p>
+</div>
+<div class="section" id="object-loading">
+<h2>Object Loading<a class="headerlink" href="#object-loading" title="Permalink to this headline">¶</a></h2>
+<p>Once an object image has been obtained, either through code generation or
+having been retrieved from an ObjectCache, it is passed to RuntimeDyld to
+be loaded.  The RuntimeDyld wrapper class examines the object to determine
+its file format and creates an instance of either RuntimeDyldELF or
+RuntimeDyldMachO (both of which derive from the RuntimeDyldImpl base
+class) and calls the RuntimeDyldImpl::loadObject method to perform that
+actual loading.</p>
+<img alt="_images/MCJIT-dyld-load.png" src="_images/MCJIT-dyld-load.png" />
+<p>RuntimeDyldImpl::loadObject begins by creating an ObjectImage instance
+from the ObjectBuffer it received.  ObjectImage, which wraps the
+ObjectFile class, is a helper class which parses the binary object image
+and provides access to the information contained in the format-specific
+headers, including section, symbol and relocation information.</p>
+<p>RuntimeDyldImpl::loadObject then iterates through the symbols in the
+image.  Information about common symbols is collected for later use.  For
+each function or data symbol, the associated section is loaded into memory
+and the symbol is stored in a symbol table map data structure.  When the
+iteration is complete, a section is emitted for the common symbols.</p>
+<p>Next, RuntimeDyldImpl::loadObject iterates through the sections in the
+object image and for each section iterates through the relocations for
+that sections.  For each relocation, it calls the format-specific
+processRelocationRef method, which will examine the relocation and store
+it in one of two data structures, a section-based relocation list map and
+an external symbol relocation map.</p>
+<img alt="_images/MCJIT-load-object.png" src="_images/MCJIT-load-object.png" />
+<p>When RuntimeDyldImpl::loadObject returns, all of the code and data
+sections for the object will have been loaded into memory allocated by the
+memory manager and relocation information will have been prepared, but the
+relocations have not yet been applied and the generated code is still not
+ready to be executed.</p>
+<p>[Currently (as of August 2013) the MCJIT engine will immediately apply
+relocations when loadObject completes.  However, this shouldn’t be
+happening.  Because the code may have been generated for a remote target,
+the client should be given a chance to re-map the section addresses before
+relocations are applied.  It is possible to apply relocations multiple
+times, but in the case where addresses are to be re-mapped, this first
+application is wasted effort.]</p>
+</div>
+<div class="section" id="address-remapping">
+<h2>Address Remapping<a class="headerlink" href="#address-remapping" title="Permalink to this headline">¶</a></h2>
+<p>At any time after initial code has been generated and before
+finalizeObject is called, the client can remap the address of sections in
+the object.  Typically this is done because the code was generated for an
+external process and is being mapped into that process’ address space.
+The client remaps the section address by calling MCJIT::mapSectionAddress.
+This should happen before the section memory is copied to its new
+location.</p>
+<p>When MCJIT::mapSectionAddress is called, MCJIT passes the call on to
+RuntimeDyldImpl (via its Dyld member).  RuntimeDyldImpl stores the new
+address in an internal data structure but does not update the code at this
+time, since other sections are likely to change.</p>
+<p>When the client is finished remapping section addresses, it will call
+MCJIT::finalizeObject to complete the remapping process.</p>
+</div>
+<div class="section" id="final-preparations">
+<h2>Final Preparations<a class="headerlink" href="#final-preparations" title="Permalink to this headline">¶</a></h2>
+<p>When MCJIT::finalizeObject is called, MCJIT calls
+RuntimeDyld::resolveRelocations.  This function will attempt to locate any
+external symbols and then apply all relocations for the object.</p>
+<p>External symbols are resolved by calling the memory manager’s
+getPointerToNamedFunction method.  The memory manager will return the
+address of the requested symbol in the target address space.  (Note, this
+may not be a valid pointer in the host process.)  RuntimeDyld will then
+iterate through the list of relocations it has stored which are associated
+with this symbol and invoke the resolveRelocation method which, through an
+format-specific implementation, will apply the relocation to the loaded
+section memory.</p>
+<p>Next, RuntimeDyld::resolveRelocations iterates through the list of
+sections and for each section iterates through a list of relocations that
+have been saved which reference that symbol and call resolveRelocation for
+each entry in this list.  The relocation list here is a list of
+relocations for which the symbol associated with the relocation is located
+in the section associated with the list.  Each of these locations will
+have a target location at which the relocation will be applied that is
+likely located in a different section.</p>
+<img alt="_images/MCJIT-resolve-relocations.png" src="_images/MCJIT-resolve-relocations.png" />
+<p>Once relocations have been applied as described above, MCJIT calls
+RuntimeDyld::getEHFrameSection, and if a non-zero result is returned
+passes the section data to the memory manager’s registerEHFrames method.
+This allows the memory manager to call any desired target-specific
+functions, such as registering the EH frame information with a debugger.</p>
+<p>Finally, MCJIT calls the memory manager’s finalizeMemory method.  In this
+method, the memory manager will invalidate the target code cache, if
+necessary, and apply final permissions to the memory pages it has
+allocated for code and data memory.</p>
+</div>
+</div>
+
+
+          </div>
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+  <div class="section" id="llvm-makefile-guide">
+<h1>LLVM Makefile Guide<a class="headerlink" href="#llvm-makefile-guide" title="Permalink to this headline">¶</a></h1>
+<div class="contents local topic" id="contents">
+<ul class="simple">
+<li><a class="reference internal" href="#introduction" id="id3">Introduction</a></li>
+<li><a class="reference internal" href="#general-concepts" id="id4">General Concepts</a><ul>
+<li><a class="reference internal" href="#projects" id="id5">Projects</a></li>
+<li><a class="reference internal" href="#variable-values" id="id6">Variable Values</a></li>
+<li><a class="reference internal" href="#including-makefiles" id="id7">Including Makefiles</a><ul>
+<li><a class="reference internal" href="#makefile" id="id8"><tt class="docutils literal"><span class="pre">Makefile</span></tt></a></li>
+<li><a class="reference internal" href="#makefile-common" id="id9"><tt class="docutils literal"><span class="pre">Makefile.common</span></tt></a></li>
+<li><a class="reference internal" href="#makefile-config" id="id10"><tt class="docutils literal"><span class="pre">Makefile.config</span></tt></a></li>
+<li><a class="reference internal" href="#makefile-rules" id="id11"><tt class="docutils literal"><span class="pre">Makefile.rules</span></tt></a></li>
+<li><a class="reference internal" href="#comments" id="id12">Comments</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#tutorial" id="id13">Tutorial</a><ul>
+<li><a class="reference internal" href="#libraries" id="id14">Libraries</a><ul>
+<li><a class="reference internal" href="#loadable-modules" id="id15">Loadable Modules</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#tools" id="id16">Tools</a><ul>
+<li><a class="reference internal" href="#jit-tools" id="id17">JIT Tools</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li><a class="reference internal" href="#targets-supported" id="id18">Targets Supported</a><ul>
+<li><a class="reference internal" href="#all-default" id="id19"><tt class="docutils literal"><span class="pre">all</span></tt> (default)</a></li>
+<li><a class="reference internal" href="#all-local" id="id20"><tt class="docutils literal"><span class="pre">all-local</span></tt></a></li>
+<li><a class="reference internal" href="#check" id="id21"><tt class="docutils literal"><span class="pre">check</span></tt></a></li>
+<li><a class="reference internal" href="#check-local" id="id22"><tt class="docutils literal"><span class="pre">check-local</span></tt></a></li>
+<li><a class="reference internal" href="#clean" id="id23"><tt class="docutils literal"><span class="pre">clean</span></tt></a></li>
+<li><a class="reference internal" href="#clean-local" id="id24"><tt class="docutils literal"><span class="pre">clean-local</span></tt></a></li>
+<li><a class="reference internal" href="#dist" id="id25"><tt class="docutils literal"><span class="pre">dist</span></tt></a></li>
+<li><a class="reference internal" href="#dist-check" id="id26"><tt class="docutils literal"><span class="pre">dist-check</span></tt></a></li>
+<li><a class="reference internal" href="#dist-clean" id="id27"><tt class="docutils literal"><span class="pre">dist-clean</span></tt></a></li>
+<li><a class="reference internal" href="#install" id="id28"><tt class="docutils literal"><span class="pre">install</span></tt></a></li>
+<li><a class="reference internal" href="#preconditions" id="id29"><tt class="docutils literal"><span class="pre">preconditions</span></tt></a></li>
+<li><a class="reference internal" href="#printvars" id="id30"><tt class="docutils literal"><span class="pre">printvars</span></tt></a></li>
+<li><a class="reference internal" href="#reconfigure" id="id31"><tt class="docutils literal"><span class="pre">reconfigure</span></tt></a></li>
+<li><a class="reference internal" href="#spotless" id="id32"><tt class="docutils literal"><span class="pre">spotless</span></tt></a></li>
+<li><a class="reference internal" href="#tags" id="id33"><tt class="docutils literal"><span class="pre">tags</span></tt></a></li>
+<li><a class="reference internal" href="#uninstall" id="id34"><tt class="docutils literal"><span class="pre">uninstall</span></tt></a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#variables" id="id35">Variables</a><ul>
+<li><a class="reference internal" href="#control-variables" id="id36">Control Variables</a></li>
+<li><a class="reference internal" href="#override-variables" id="id37">Override Variables</a></li>
+<li><a class="reference internal" href="#readable-variables" id="id38">Readable Variables</a></li>
+<li><a class="reference internal" href="#internal-variables" id="id39">Internal Variables</a></li>
+</ul>
+</li>
+</ul>
+</div>
+<div class="section" id="introduction">
+<h2><a class="toc-backref" href="#id3">Introduction</a><a class="headerlink" href="#introduction" title="Permalink to this headline">¶</a></h2>
+<p>This document provides <em>usage</em> information about the LLVM makefile system. While
+loosely patterned after the BSD makefile system, LLVM has taken a departure from
+BSD in order to implement additional features needed by LLVM.  Although makefile
+systems, such as <tt class="docutils literal"><span class="pre">automake</span></tt>, were attempted at one point, it has become clear
+that the features needed by LLVM and the <tt class="docutils literal"><span class="pre">Makefile</span></tt> norm are too great to use
+a more limited tool. Consequently, LLVM requires simply GNU Make 3.79, a widely
+portable makefile processor. LLVM unabashedly makes heavy use of the features of
+GNU Make so the dependency on GNU Make is firm. If you’re not familiar with
+<tt class="docutils literal"><span class="pre">make</span></tt>, it is recommended that you read the <a class="reference external" href="http://www.gnu.org/software/make/manual/make.html">GNU Makefile Manual</a>.</p>
+<p>While this document is rightly part of the <a class="reference external" href="ProgrammersManual.html">LLVM Programmer’s
+Manual</a>, it is treated separately here because of the
+volume of content and because it is often an early source of bewilderment for
+new developers.</p>
+</div>
+<div class="section" id="general-concepts">
+<h2><a class="toc-backref" href="#id4">General Concepts</a><a class="headerlink" href="#general-concepts" title="Permalink to this headline">¶</a></h2>
+<p>The LLVM Makefile System is the component of LLVM that is responsible for
+building the software, testing it, generating distributions, checking those
+distributions, installing and uninstalling, etc. It consists of a several files
+throughout the source tree. These files and other general concepts are described
+in this section.</p>
+<div class="section" id="projects">
+<h3><a class="toc-backref" href="#id5">Projects</a><a class="headerlink" href="#projects" title="Permalink to this headline">¶</a></h3>
+<p>The LLVM Makefile System is quite generous. It not only builds its own software,
+but it can build yours too. Built into the system is knowledge of the
+<tt class="docutils literal"><span class="pre">llvm/projects</span></tt> directory. Any directory under <tt class="docutils literal"><span class="pre">projects</span></tt> that has both a
+<tt class="docutils literal"><span class="pre">configure</span></tt> script and a <tt class="docutils literal"><span class="pre">Makefile</span></tt> is assumed to be a project that uses the
+LLVM Makefile system.  Building software that uses LLVM does not require the
+LLVM Makefile System nor even placement in the <tt class="docutils literal"><span class="pre">llvm/projects</span></tt>
+directory. However, doing so will allow your project to get up and running
+quickly by utilizing the built-in features that are used to compile LLVM. LLVM
+compiles itself using the same features of the makefile system as used for
+projects.</p>
+<p>For further details, consult the <a class="reference external" href="Projects.html">Projects</a> page.</p>
+</div>
+<div class="section" id="variable-values">
+<h3><a class="toc-backref" href="#id6">Variable Values</a><a class="headerlink" href="#variable-values" title="Permalink to this headline">¶</a></h3>
+<p>To use the makefile system, you simply create a file named <tt class="docutils literal"><span class="pre">Makefile</span></tt> in your
+directory and declare values for certain variables.  The variables and values
+that you select determine what the makefile system will do. These variables
+enable rules and processing in the makefile system that automatically Do The
+Right Thing (C).</p>
+</div>
+<div class="section" id="including-makefiles">
+<h3><a class="toc-backref" href="#id7">Including Makefiles</a><a class="headerlink" href="#including-makefiles" title="Permalink to this headline">¶</a></h3>
+<p>Setting variables alone is not enough. You must include into your Makefile
+additional files that provide the rules of the LLVM Makefile system. The various
+files involved are described in the sections that follow.</p>
+<div class="section" id="makefile">
+<h4><a class="toc-backref" href="#id8"><tt class="docutils literal"><span class="pre">Makefile</span></tt></a><a class="headerlink" href="#makefile" title="Permalink to this headline">¶</a></h4>
+<p>Each directory to participate in the build needs to have a file named
+<tt class="docutils literal"><span class="pre">Makefile</span></tt>. This is the file first read by <tt class="docutils literal"><span class="pre">make</span></tt>. It has three
+sections:</p>
+<ol class="arabic simple">
+<li>Settable Variables — Required that must be set first.</li>
+<li><tt class="docutils literal"><span class="pre">include</span> <span class="pre">$(LEVEL)/Makefile.common</span></tt> — include the LLVM Makefile system.</li>
+<li>Override Variables — Override variables set by the LLVM Makefile system.</li>
+</ol>
+</div>
+<div class="section" id="makefile-common">
+<span id="level-makefile-common"></span><h4><a class="toc-backref" href="#id9"><tt class="docutils literal"><span class="pre">Makefile.common</span></tt></a><a class="headerlink" href="#makefile-common" title="Permalink to this headline">¶</a></h4>
+<p>Every project must have a <tt class="docutils literal"><span class="pre">Makefile.common</span></tt> file at its top source
+directory. This file serves three purposes:</p>
+<ol class="arabic simple">
+<li>It includes the project’s configuration makefile to obtain values determined
+by the <tt class="docutils literal"><span class="pre">configure</span></tt> script. This is done by including the
+<a class="reference internal" href="#level-makefile-config">$(LEVEL)/Makefile.config</a> file.</li>
+<li>It specifies any other (static) values that are needed throughout the
+project. Only values that are used in all or a large proportion of the
+project’s directories should be placed here.</li>
+<li>It includes the standard rules for the LLVM Makefile system,
+<a class="reference internal" href="#llvm-src-root-makefile-rules">$(LLVM_SRC_ROOT)/Makefile.rules</a>.  This file is the <em>guts</em> of the LLVM
+<tt class="docutils literal"><span class="pre">Makefile</span></tt> system.</li>
+</ol>
+</div>
+<div class="section" id="makefile-config">
+<span id="level-makefile-config"></span><h4><a class="toc-backref" href="#id10"><tt class="docutils literal"><span class="pre">Makefile.config</span></tt></a><a class="headerlink" href="#makefile-config" title="Permalink to this headline">¶</a></h4>
+<p>Every project must have a <tt class="docutils literal"><span class="pre">Makefile.config</span></tt> at the top of its <em>build</em>
+directory. This file is <strong>generated</strong> by the <tt class="docutils literal"><span class="pre">configure</span></tt> script from the
+pattern provided by the <tt class="docutils literal"><span class="pre">Makefile.config.in</span></tt> file located at the top of the
+project’s <em>source</em> directory. The contents of this file depend largely on what
+configuration items the project uses, however most projects can get what they
+need by just relying on LLVM’s configuration found in
+<tt class="docutils literal"><span class="pre">$(LLVM_OBJ_ROOT)/Makefile.config</span></tt>.</p>
+</div>
+<div class="section" id="makefile-rules">
+<span id="llvm-src-root-makefile-rules"></span><h4><a class="toc-backref" href="#id11"><tt class="docutils literal"><span class="pre">Makefile.rules</span></tt></a><a class="headerlink" href="#makefile-rules" title="Permalink to this headline">¶</a></h4>
+<p>This file, located at <tt class="docutils literal"><span class="pre">$(LLVM_SRC_ROOT)/Makefile.rules</span></tt> is the heart of the
+LLVM Makefile System. It provides all the logic, dependencies, and rules for
+building the targets supported by the system. What it does largely depends on
+the values of <tt class="docutils literal"><span class="pre">make</span></tt> <a class="reference internal" href="#variables">variables</a> that have been set <em>before</em>
+<tt class="docutils literal"><span class="pre">Makefile.rules</span></tt> is included.</p>
+</div>
+<div class="section" id="comments">
+<h4><a class="toc-backref" href="#id12">Comments</a><a class="headerlink" href="#comments" title="Permalink to this headline">¶</a></h4>
+<p>User <tt class="docutils literal"><span class="pre">Makefile</span></tt>s need not have comments in them unless the construction is
+unusual or it does not strictly follow the rules and patterns of the LLVM
+makefile system. Makefile comments are invoked with the pound (<tt class="docutils literal"><span class="pre">#</span></tt>) character.
+The <tt class="docutils literal"><span class="pre">#</span></tt> character and any text following it, to the end of the line, are
+ignored by <tt class="docutils literal"><span class="pre">make</span></tt>.</p>
+</div>
+</div>
+</div>
+<div class="section" id="tutorial">
+<h2><a class="toc-backref" href="#id13">Tutorial</a><a class="headerlink" href="#tutorial" title="Permalink to this headline">¶</a></h2>
+<p>This section provides some examples of the different kinds of modules you can
+build with the LLVM makefile system. In general, each directory you provide will
+build a single object although that object may be composed of additionally
+compiled components.</p>
+<div class="section" id="libraries">
+<h3><a class="toc-backref" href="#id14">Libraries</a><a class="headerlink" href="#libraries" title="Permalink to this headline">¶</a></h3>
+<p>Only a few variable definitions are needed to build a regular library.
+Normally, the makefile system will build all the software into a single
+<tt class="docutils literal"><span class="pre">libname.o</span></tt> (pre-linked) object. This means the library is not searchable and
+that the distinction between compilation units has been dissolved. Optionally,
+you can ask for a shared library (.so) or archive library (.a) built.  Archive
+libraries are the default. For example:</p>
+<div class="highlight-makefile"><div class="highlight"><pre><span class="nv">LIBRARYNAME</span> <span class="o">=</span> mylib
+<span class="nv">SHARED_LIBRARY</span> <span class="o">=</span> 1
+<span class="nv">BUILD_ARCHIVE</span> <span class="o">=</span> 1
+</pre></div>
+</div>
+<p>says to build a library named <tt class="docutils literal"><span class="pre">mylib</span></tt> with both a shared library
+(<tt class="docutils literal"><span class="pre">mylib.so</span></tt>) and an archive library (<tt class="docutils literal"><span class="pre">mylib.a</span></tt>) version. The contents of all
+the libraries produced will be the same, they are just constructed differently.
+Note that you normally do not need to specify the sources involved. The LLVM
+Makefile system will infer the source files from the contents of the source
+directory.</p>
+<p>The <tt class="docutils literal"><span class="pre">LOADABLE_MODULE=1</span></tt> directive can be used in conjunction with
+<tt class="docutils literal"><span class="pre">SHARED_LIBRARY=1</span></tt> to indicate that the resulting shared library should be
+openable with the <tt class="docutils literal"><span class="pre">dlopen</span></tt> function and searchable with the <tt class="docutils literal"><span class="pre">dlsym</span></tt> function
+(or your operating system’s equivalents). While this isn’t strictly necessary on
+Linux and a few other platforms, it is required on systems like HP-UX and
+Darwin. You should use <tt class="docutils literal"><span class="pre">LOADABLE_MODULE</span></tt> for any shared library that you
+intend to be loaded into an tool via the <tt class="docutils literal"><span class="pre">-load</span></tt> option.  <a class="reference internal" href="WritingAnLLVMPass.html#writing-an-llvm-pass-makefile"><em>Pass
+documentation</em></a> has an example of why you might
+want to do this.</p>
+<div class="section" id="loadable-modules">
+<h4><a class="toc-backref" href="#id15">Loadable Modules</a><a class="headerlink" href="#loadable-modules" title="Permalink to this headline">¶</a></h4>
+<p>In some situations, you need to create a loadable module. Loadable modules can
+be loaded into programs like <tt class="docutils literal"><span class="pre">opt</span></tt> or <tt class="docutils literal"><span class="pre">llc</span></tt> to specify additional passes to
+run or targets to support.  Loadable modules are also useful for debugging a
+pass or providing a pass with another package if that pass can’t be included in
+LLVM.</p>
+<p>LLVM provides complete support for building such a module. All you need to do is
+use the <tt class="docutils literal"><span class="pre">LOADABLE_MODULE</span></tt> variable in your <tt class="docutils literal"><span class="pre">Makefile</span></tt>. For example, to build
+a loadable module named <tt class="docutils literal"><span class="pre">MyMod</span></tt> that uses the LLVM libraries <tt class="docutils literal"><span class="pre">LLVMSupport.a</span></tt>
+and <tt class="docutils literal"><span class="pre">LLVMSystem.a</span></tt>, you would specify:</p>
+<div class="highlight-makefile"><div class="highlight"><pre><span class="nv">LIBRARYNAME</span> <span class="o">:=</span> MyMod
+<span class="nv">LOADABLE_MODULE</span> <span class="o">:=</span> 1
+<span class="nv">LINK_COMPONENTS</span> <span class="o">:=</span> support system
+</pre></div>
+</div>
+<p>Use of the <tt class="docutils literal"><span class="pre">LOADABLE_MODULE</span></tt> facility implies several things:</p>
+<ol class="arabic">
+<li><dl class="first docutils">
+<dt>There will be no “<tt class="docutils literal"><span class="pre">lib</span></tt>” prefix on the module. This differentiates it from</dt>
+<dd><p class="first last">a standard shared library of the same name.</p>
+</dd>
+</dl>
+</li>
+<li><p class="first">The <a class="reference internal" href="#shared-library">SHARED_LIBRARY</a> variable is turned on.</p>
+</li>
+<li><p class="first">The <a class="reference internal" href="#link-libs-in-shared">LINK_LIBS_IN_SHARED</a> variable is turned on.</p>
+</li>
+</ol>
+<p>A loadable module is loaded by LLVM via the facilities of libtool’s libltdl
+library which is part of <tt class="docutils literal"><span class="pre">lib/System</span></tt> implementation.</p>
+</div>
+</div>
+<div class="section" id="tools">
+<h3><a class="toc-backref" href="#id16">Tools</a><a class="headerlink" href="#tools" title="Permalink to this headline">¶</a></h3>
+<p>For building executable programs (tools), you must provide the name of the tool
+and the names of the libraries you wish to link with the tool. For example:</p>
+<div class="highlight-makefile"><div class="highlight"><pre><span class="nv">TOOLNAME</span> <span class="o">=</span> mytool
+<span class="nv">USEDLIBS</span> <span class="o">=</span> mylib
+<span class="nv">LINK_COMPONENTS</span> <span class="o">=</span> support system
+</pre></div>
+</div>
+<p>says that we are to build a tool name <tt class="docutils literal"><span class="pre">mytool</span></tt> and that it requires three
+libraries: <tt class="docutils literal"><span class="pre">mylib</span></tt>, <tt class="docutils literal"><span class="pre">LLVMSupport.a</span></tt> and <tt class="docutils literal"><span class="pre">LLVMSystem.a</span></tt>.</p>
+<p>Note that two different variables are used to indicate which libraries are
+linked: <tt class="docutils literal"><span class="pre">USEDLIBS</span></tt> and <tt class="docutils literal"><span class="pre">LLVMLIBS</span></tt>. This distinction is necessary to support
+projects. <tt class="docutils literal"><span class="pre">LLVMLIBS</span></tt> refers to the LLVM libraries found in the LLVM object
+directory. <tt class="docutils literal"><span class="pre">USEDLIBS</span></tt> refers to the libraries built by your project. In the
+case of building LLVM tools, <tt class="docutils literal"><span class="pre">USEDLIBS</span></tt> and <tt class="docutils literal"><span class="pre">LLVMLIBS</span></tt> can be used
+interchangeably since the “project” is LLVM itself and <tt class="docutils literal"><span class="pre">USEDLIBS</span></tt> refers to
+the same place as <tt class="docutils literal"><span class="pre">LLVMLIBS</span></tt>.</p>
+<p>Also note that there are two different ways of specifying a library: with a
+<tt class="docutils literal"><span class="pre">.a</span></tt> suffix and without. Without the suffix, the entry refers to the re-linked
+(.o) file which will include <em>all</em> symbols of the library.  This is
+useful, for example, to include all passes from a library of passes.  If the
+<tt class="docutils literal"><span class="pre">.a</span></tt> suffix is used then the library is linked as a searchable library (with
+the <tt class="docutils literal"><span class="pre">-l</span></tt> option). In this case, only the symbols that are unresolved <em>at
+that point</em> will be resolved from the library, if they exist. Other
+(unreferenced) symbols will not be included when the <tt class="docutils literal"><span class="pre">.a</span></tt> syntax is used. Note
+that in order to use the <tt class="docutils literal"><span class="pre">.a</span></tt> suffix, the library in question must have been
+built with the <tt class="docutils literal"><span class="pre">BUILD_ARCHIVE</span></tt> option set.</p>
+<div class="section" id="jit-tools">
+<h4><a class="toc-backref" href="#id17">JIT Tools</a><a class="headerlink" href="#jit-tools" title="Permalink to this headline">¶</a></h4>
+<p>Many tools will want to use the JIT features of LLVM.  To do this, you simply
+specify that you want an execution ‘engine’, and the makefiles will
+automatically link in the appropriate JIT for the host or an interpreter if none
+is available:</p>
+<div class="highlight-makefile"><div class="highlight"><pre><span class="nv">TOOLNAME</span> <span class="o">=</span> my_jit_tool
+<span class="nv">USEDLIBS</span> <span class="o">=</span> mylib
+<span class="nv">LINK_COMPONENTS</span> <span class="o">=</span> engine
+</pre></div>
+</div>
+<p>Of course, any additional libraries may be listed as other components.  To get a
+full understanding of how this changes the linker command, it is recommended
+that you:</p>
+<div class="highlight-bash"><div class="highlight"><pre>% <span class="nb">cd </span>examples/Fibonacci
+% make <span class="nv">VERBOSE</span><span class="o">=</span>1
+</pre></div>
+</div>
+</div>
+</div>
+</div>
+<div class="section" id="targets-supported">
+<h2><a class="toc-backref" href="#id18">Targets Supported</a><a class="headerlink" href="#targets-supported" title="Permalink to this headline">¶</a></h2>
+<p>This section describes each of the targets that can be built using the LLVM
+Makefile system. Any target can be invoked from any directory but not all are
+applicable to a given directory (e.g. “check”, “dist” and “install” will always
+operate as if invoked from the top level directory).</p>
+<table border="1" class="docutils">
+<colgroup>
+<col width="12%" />
+<col width="10%" />
+<col width="78%" />
+</colgroup>
+<thead valign="bottom">
+<tr class="row-odd"><th class="head">Target Name</th>
+<th class="head">Implied Targets</th>
+<th class="head">Target Description</th>
+</tr>
+</thead>
+<tbody valign="top">
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">all</span></tt></td>
+<td></td>
+<td>Compile the software recursively. Default target.</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">all-local</span></tt></td>
+<td></td>
+<td>Compile the software in the local directory only.</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">check</span></tt></td>
+<td></td>
+<td>Change to the <tt class="docutils literal"><span class="pre">test</span></tt> directory in a project and run the test suite there.</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">check-local</span></tt></td>
+<td></td>
+<td>Run a local test suite. Generally this is only defined in the  <tt class="docutils literal"><span class="pre">Makefile</span></tt> of the project’s <tt class="docutils literal"><span class="pre">test</span></tt> directory.</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">clean</span></tt></td>
+<td></td>
+<td>Remove built objects recursively.</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">clean-local</span></tt></td>
+<td></td>
+<td>Remove built objects from the local directory only.</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">dist</span></tt></td>
+<td><tt class="docutils literal"><span class="pre">all</span></tt></td>
+<td>Prepare a source distribution tarball.</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">dist-check</span></tt></td>
+<td><tt class="docutils literal"><span class="pre">all</span></tt></td>
+<td>Prepare a source distribution tarball and check that it builds.</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">dist-clean</span></tt></td>
+<td><tt class="docutils literal"><span class="pre">clean</span></tt></td>
+<td>Clean source distribution tarball temporary files.</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">install</span></tt></td>
+<td><tt class="docutils literal"><span class="pre">all</span></tt></td>
+<td>Copy built objects to installation directory.</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">preconditions</span></tt></td>
+<td><tt class="docutils literal"><span class="pre">all</span></tt></td>
+<td>Check to make sure configuration and makefiles are up to date.</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">printvars</span></tt></td>
+<td><tt class="docutils literal"><span class="pre">all</span></tt></td>
+<td>Prints variables defined by the makefile system (for debugging).</td>
+</tr>
+<tr class="row-even"><td><tt class="docutils literal"><span class="pre">tags</span></tt></td>
+<td></td>
+<td>Make C and C++ tags files for emacs and vi.</td>
+</tr>
+<tr class="row-odd"><td><tt class="docutils literal"><span class="pre">uninstall</span></tt></td>
+<td></td>
+<td>Remove built objects from installation directory.</td>
+</tr>
+</tbody>
+</table>
+<div class="section" id="all-default">
+<span id="all"></span><h3><a class="toc-backref" href="#id19"><tt class="docutils literal"><span class="pre">all</span></tt> (default)</a><a class="headerlink" href="#all-default" title="Permalink to this headline">¶</a></h3>
+<p>When you invoke <tt class="docutils literal"><span class="pre">make</span></tt> with no arguments, you are implicitly instructing it to
+seek the <tt class="docutils literal"><span class="pre">all</span></tt> target (goal). This target is used for building the software
+recursively and will do different things in different directories.  For example,
+in a <tt class="docutils literal"><span class="pre">lib</span></tt> directory, the <tt class="docutils literal"><span class="pre">all</span></tt> target will compile source files and
+generate libraries. But, in a <tt class="docutils literal"><span class="pre">tools</span></tt> directory, it will link libraries and
+generate executables.</p>
+</div>
+<div class="section" id="all-local">
+<h3><a class="toc-backref" href="#id20"><tt class="docutils literal"><span class="pre">all-local</span></tt></a><a class="headerlink" href="#all-local" title="Permalink to this headline">¶</a></h3>
+<p>This target is the same as <a class="reference internal" href="#all">all</a> but it operates only on the current directory
+instead of recursively.</p>
+</div>
+<div class="section" id="check">
+<h3><a class="toc-backref" href="#id21"><tt class="docutils literal"><span class="pre">check</span></tt></a><a class="headerlink" href="#check" title="Permalink to this headline">¶</a></h3>
+<p>This target can be invoked from anywhere within a project’s directories but
+always invokes the <a class="reference internal" href="#check-local">check-local</a> target in the project’s <tt class="docutils literal"><span class="pre">test</span></tt> directory, if
+it exists and has a <tt class="docutils literal"><span class="pre">Makefile</span></tt>. A warning is produced otherwise.  If
+<a class="reference internal" href="#testsuite">TESTSUITE</a> is defined on the <tt class="docutils literal"><span class="pre">make</span></tt> command line, it will be passed down to
+the invocation of <tt class="docutils literal"><span class="pre">make</span> <span class="pre">check-local</span></tt> in the <tt class="docutils literal"><span class="pre">test</span></tt> directory. The intended
+usage for this is to assist in running specific suites of tests. If
+<tt class="docutils literal"><span class="pre">TESTSUITE</span></tt> is not set, the implementation of <tt class="docutils literal"><span class="pre">check-local</span></tt> should run all
+normal tests.  It is up to the project to define what different values for
+<tt class="docutils literal"><span class="pre">TESTSUTE</span></tt> will do. See the <a class="reference internal" href="TestingGuide.html"><em>Testing Guide</em></a> for further
+details.</p>
+</div>
+<div class="section" id="check-local">
+<h3><a class="toc-backref" href="#id22"><tt class="docutils literal"><span class="pre">check-local</span></tt></a><a class="headerlink" href="#check-local" title="Permalink to this headline">¶</a></h3>
+<p>This target should be implemented by the <tt class="docutils literal"><span class="pre">Makefile</span></tt> in the project’s <tt class="docutils literal"><span class="pre">test</span></tt>
+directory. It is invoked by the <tt class="docutils literal"><span class="pre">check</span></tt> target elsewhere.  Each project is
+free to define the actions of <tt class="docutils literal"><span class="pre">check-local</span></tt> as appropriate for that
+project. The LLVM project itself uses the <a class="reference internal" href="CommandGuide/lit.html"><em>Lit</em></a> testing
+tool to run a suite of feature and regression tests. Other projects may choose
+to use <strong class="program">lit</strong> or any other testing mechanism.</p>
+</div>
+<div class="section" id="clean">
+<h3><a class="toc-backref" href="#id23"><tt class="docutils literal"><span class="pre">clean</span></tt></a><a class="headerlink" href="#clean" title="Permalink to this headline">¶</a></h3>
+<p>This target cleans the build directory, recursively removing all things that the
+Makefile builds. The cleaning rules have been made guarded so they shouldn’t go
+awry (via <tt class="docutils literal"><span class="pre">rm</span> <span class="pre">-f</span> <span class="pre">$(UNSET_VARIABLE)/*</span></tt> which will attempt to erase the entire
+directory structure).</p>
+</div>
+<div class="section" id="clean-local">
+<h3><a class="toc-backref" href="#id24"><tt class="docutils literal"><span class="pre">clean-local</span></tt></a><a class="headerlink" href="#clean-local" title="Permalink to this headline">¶</a></h3>
+<p>This target does the same thing as <tt class="docutils literal"><span class="pre">clean</span></tt> but only for the current (local)
+directory.</p>
+</div>
+<div class="section" id="dist">
+<h3><a class="toc-backref" href="#id25"><tt class="docutils literal"><span class="pre">dist</span></tt></a><a class="headerlink" href="#dist" title="Permalink to this headline">¶</a></h3>
+<p>This target builds a distribution tarball. It first builds the entire project
+using the <tt class="docutils literal"><span class="pre">all</span></tt> target and then tars up the necessary files and compresses
+it. The generated tarball is sufficient for a casual source distribution, but
+probably not for a release (see <tt class="docutils literal"><span class="pre">dist-check</span></tt>).</p>
+</div>
+<div class="section" id="dist-check">
+<h3><a class="toc-backref" href="#id26"><tt class="docutils literal"><span class="pre">dist-check</span></tt></a><a class="headerlink" href="#dist-check" title="Permalink to this headline">¶</a></h3>
+<p>This target does the same thing as the <tt class="docutils literal"><span class="pre">dist</span></tt> target but also checks the
+distribution tarball. The check is made by unpacking the tarball to a new
+directory, configuring it, building it, installing it, and then verifying that
+the installation results are correct (by comparing to the original build).  This
+target can take a long time to run but should be done before a release goes out
+to make sure that the distributed tarball can actually be built into a working
+release.</p>
+</div>
+<div class="section" id="dist-clean">
+<h3><a class="toc-backref" href="#id27"><tt class="docutils literal"><span class="pre">dist-clean</span></tt></a><a class="headerlink" href="#dist-clean" title="Permalink to this headline">¶</a></h3>
+<p>This is a special form of the <tt class="docutils literal"><span class="pre">clean</span></tt> clean target. It performs a normal
+<tt class="docutils literal"><span class="pre">clean</span></tt> but also removes things pertaining to building the distribution.</p>
+</div>
+<div class="section" id="install">
+<h3><a class="toc-backref" href="#id28"><tt class="docutils literal"><span class="pre">install</span></tt></a><a class="headerlink" href="#install" title="Permalink to this headline">¶</a></h3>
+<p>This target finalizes shared objects and executables and copies all libraries,
+headers, executables and documentation to the directory given with the
+<tt class="docutils literal"><span class="pre">--prefix</span></tt> option to <tt class="docutils literal"><span class="pre">configure</span></tt>.  When completed, the prefix directory will
+have everything needed to <strong>use</strong> LLVM.</p>
+<p>The LLVM makefiles can generate complete <strong>internal</strong> documentation for all the
+classes by using <tt class="docutils literal"><span class="pre">doxygen</span></tt>. By default, this feature is <strong>not</strong> enabled
+because it takes a long time and generates a massive amount of data (>100MB). If
+you want this feature, you must configure LLVM with the –enable-doxygen switch
+and ensure that a modern version of doxygen (1.3.7 or later) is available in
+your <tt class="docutils literal"><span class="pre">PATH</span></tt>. You can download doxygen from <a class="reference external" href="http://www.stack.nl/~dimitri/doxygen/download.html#latestsrc">here</a>.</p>
+</div>
+<div class="section" id="preconditions">
+<h3><a class="toc-backref" href="#id29"><tt class="docutils literal"><span class="pre">preconditions</span></tt></a><a class="headerlink" href="#preconditions" title="Permalink to this headline">¶</a></h3>
+<p>This utility target checks to see if the <tt class="docutils literal"><span class="pre">Makefile</span></tt> in the object directory is
+older than the <tt class="docutils literal"><span class="pre">Makefile</span></tt> in the source directory and copies it if so. It also
+reruns the <tt class="docutils literal"><span class="pre">configure</span></tt> script if that needs to be done and rebuilds the
+<tt class="docutils literal"><span class="pre">Makefile.config</span></tt> file similarly. Users may overload this target to ensure
+that sanity checks are run <em>before</em> any building of targets as all the targets
+depend on <tt class="docutils literal"><span class="pre">preconditions</span></tt>.</p>
+</div>
+<div class="section" id="printvars">
+<h3><a class="toc-backref" href="#id30"><tt class="docutils literal"><span class="pre">printvars</span></tt></a><a class="headerlink" href="#printvars" title="Permalink to this headline">¶</a></h3>
+<p>This utility target just causes the LLVM makefiles to print out some of the
+makefile variables so that you can double check how things are set.</p>
+</div>
+<div class="section" id="reconfigure">
+<h3><a class="toc-backref" href="#id31"><tt class="docutils literal"><span class="pre">reconfigure</span></tt></a><a class="headerlink" href="#reconfigure" title="Permalink to this headline">¶</a></h3>
+<p>This utility target will force a reconfigure of LLVM or your project. It simply
+runs <tt class="docutils literal"><span class="pre">$(PROJ_OBJ_ROOT)/config.status</span> <span class="pre">--recheck</span></tt> to rerun the configuration
+tests and rebuild the configured files. This isn’t generally useful as the
+makefiles will reconfigure themselves whenever its necessary.</p>
+</div>
+<div class="section" id="spotless">
+<h3><a class="toc-backref" href="#id32"><tt class="docutils literal"><span class="pre">spotless</span></tt></a><a class="headerlink" href="#spotless" title="Permalink to this headline">¶</a></h3>
+<div class="admonition warning">
+<p class="first admonition-title">Warning</p>
+<p class="last">Use with caution!</p>
+</div>
+<p>This utility target, only available when <tt class="docutils literal"><span class="pre">$(PROJ_OBJ_ROOT)</span></tt> is not the same as
+<tt class="docutils literal"><span class="pre">$(PROJ_SRC_ROOT)</span></tt>, will completely clean the <tt class="docutils literal"><span class="pre">$(PROJ_OBJ_ROOT)</span></tt> directory
+by removing its content entirely and reconfiguring the directory. This returns
+the <tt class="docutils literal"><span class="pre">$(PROJ_OBJ_ROOT)</span></tt> directory to a completely fresh state. All content in
+the directory except configured files and top-level makefiles will be lost.</p>
+</div>
+<div class="section" id="tags">
+<h3><a class="toc-backref" href="#id33"><tt class="docutils literal"><span class="pre">tags</span></tt></a><a class="headerlink" href="#tags" title="Permalink to this headline">¶</a></h3>
+<p>This target will generate a <tt class="docutils literal"><span class="pre">TAGS</span></tt> file in the top-level source directory. It
+is meant for use with emacs, XEmacs, or ViM. The TAGS file provides an index of
+symbol definitions so that the editor can jump you to the definition
+quickly.</p>
+</div>
+<div class="section" id="uninstall">
+<h3><a class="toc-backref" href="#id34"><tt class="docutils literal"><span class="pre">uninstall</span></tt></a><a class="headerlink" href="#uninstall" title="Permalink to this headline">¶</a></h3>
+<p>This target is the opposite of the <tt class="docutils literal"><span class="pre">install</span></tt> target. It removes the header,
+library and executable files from the installation directories. Note that the
+directories themselves are not removed because it is not guaranteed that LLVM is
+the only thing installing there (e.g. <tt class="docutils literal"><span class="pre">--prefix=/usr</span></tt>).</p>
+</div>
+</div>
+<div class="section" id="variables">
+<span id="id2"></span><h2><a class="toc-backref" href="#id35">Variables</a><a class="headerlink" href="#variables" title="Permalink to this headline">¶</a></h2>
+<p>Variables are used to tell the LLVM Makefile System what to do and to obtain
+information from it. Variables are also used internally by the LLVM Makefile
+System. Variable names that contain only the upper case alphabetic letters and
+underscore are intended for use by the end user. All other variables are
+internal to the LLVM Makefile System and should not be relied upon nor
+modified. The sections below describe how to use the LLVM Makefile
+variables.</p>
+<div class="section" id="control-variables">
+<h3><a class="toc-backref" href="#id36">Control Variables</a><a class="headerlink" href="#control-variables" title="Permalink to this headline">¶</a></h3>
+<p>Variables listed in the table below should be set <em>before</em> the inclusion of
+<a class="reference internal" href="#level-makefile-common">$(LEVEL)/Makefile.common</a>.  These variables provide input to the LLVM make
+system that tell it what to do for the current directory.</p>
+<dl class="docutils">
+<dt><tt class="docutils literal"><span class="pre">BUILD_ARCHIVE</span></tt></dt>
+<dd>If set to any value, causes an archive (.a) library to be built.</dd>
+<dt><tt class="docutils literal"><span class="pre">BUILT_SOURCES</span></tt></dt>
+<dd>Specifies a set of source files that are generated from other source
+files. These sources will be built before any other target processing to
+ensure they are present.</dd>
+<dt><tt class="docutils literal"><span class="pre">CONFIG_FILES</span></tt></dt>
+<dd>Specifies a set of configuration files to be installed.</dd>
+<dt><tt class="docutils literal"><span class="pre">DEBUG_SYMBOLS</span></tt></dt>
+<dd>If set to any value, causes the build to include debugging symbols even in
+optimized objects, libraries and executables. This alters the flags
+specified to the compilers and linkers. Debugging isn’t fun in an optimized
+build, but it is possible.</dd>
+<dt><tt class="docutils literal"><span class="pre">DIRS</span></tt></dt>
+<dd>Specifies a set of directories, usually children of the current directory,
+that should also be made using the same goal. These directories will be
+built serially.</dd>
+<dt><tt class="docutils literal"><span class="pre">DISABLE_AUTO_DEPENDENCIES</span></tt></dt>
+<dd>If set to any value, causes the makefiles to <strong>not</strong> automatically generate
+dependencies when running the compiler. Use of this feature is discouraged
+and it may be removed at a later date.</dd>
+<dt><tt class="docutils literal"><span class="pre">ENABLE_OPTIMIZED</span></tt></dt>
+<dd>If set to 1, causes the build to generate optimized objects, libraries and
+executables. This alters the flags specified to the compilers and
+linkers. Generally debugging won’t be a fun experience with an optimized
+build.</dd>
+<dt><tt class="docutils literal"><span class="pre">ENABLE_PROFILING</span></tt></dt>
+<dd>If set to 1, causes the build to generate both optimized and profiled
+objects, libraries and executables. This alters the flags specified to the
+compilers and linkers to ensure that profile data can be collected from the
+tools built. Use the <tt class="docutils literal"><span class="pre">gprof</span></tt> tool to analyze the output from the profiled
+tools (<tt class="docutils literal"><span class="pre">gmon.out</span></tt>).</dd>
+<dt><tt class="docutils literal"><span class="pre">DISABLE_ASSERTIONS</span></tt></dt>
+<dd>If set to 1, causes the build to disable assertions, even if building a
+debug or profile build.  This will exclude all assertion check code from the
+build. LLVM will execute faster, but with little help when things go
+wrong.</dd>
+<dt><tt class="docutils literal"><span class="pre">EXPERIMENTAL_DIRS</span></tt></dt>
+<dd>Specify a set of directories that should be built, but if they fail, it
+should not cause the build to fail. Note that this should only be used
+temporarily while code is being written.</dd>
+<dt><tt class="docutils literal"><span class="pre">EXPORTED_SYMBOL_FILE</span></tt></dt>
+<dd>Specifies the name of a single file that contains a list of the symbols to
+be exported by the linker. One symbol per line.</dd>
+<dt><tt class="docutils literal"><span class="pre">EXPORTED_SYMBOL_LIST</span></tt></dt>
+<dd>Specifies a set of symbols to be exported by the linker.</dd>
+<dt><tt class="docutils literal"><span class="pre">EXTRA_DIST</span></tt></dt>
+<dd>Specifies additional files that should be distributed with LLVM. All source
+files, all built sources, all Makefiles, and most documentation files will
+be automatically distributed. Use this variable to distribute any files that
+are not automatically distributed.</dd>
+<dt><tt class="docutils literal"><span class="pre">KEEP_SYMBOLS</span></tt></dt>
+<dd>If set to any value, specifies that when linking executables the makefiles
+should retain debug symbols in the executable. Normally, symbols are
+stripped from the executable.</dd>
+<dt><tt class="docutils literal"><span class="pre">LEVEL</span></tt> (required)</dt>
+<dd>Specify the level of nesting from the top level. This variable must be set
+in each makefile as it is used to find the top level and thus the other
+makefiles.</dd>
+<dt><tt class="docutils literal"><span class="pre">LIBRARYNAME</span></tt></dt>
+<dd>Specify the name of the library to be built. (Required For Libraries)</dd>
+<dt><tt class="docutils literal"><span class="pre">LINK_COMPONENTS</span></tt></dt>
+<dd>When specified for building a tool, the value of this variable will be
+passed to the <tt class="docutils literal"><span class="pre">llvm-config</span></tt> tool to generate a link line for the
+tool. Unlike <tt class="docutils literal"><span class="pre">USEDLIBS</span></tt> and <tt class="docutils literal"><span class="pre">LLVMLIBS</span></tt>, not all libraries need to be
+specified. The <tt class="docutils literal"><span class="pre">llvm-config</span></tt> tool will figure out the library dependencies
+and add any libraries that are needed. The <tt class="docutils literal"><span class="pre">USEDLIBS</span></tt> variable can still
+be used in conjunction with <tt class="docutils literal"><span class="pre">LINK_COMPONENTS</span></tt> so that additional
+project-specific libraries can be linked with the LLVM libraries specified
+by <tt class="docutils literal"><span class="pre">LINK_COMPONENTS</span></tt>.</dd>
+</dl>
+<dl class="docutils" id="link-libs-in-shared">
+<dt><tt class="docutils literal"><span class="pre">LINK_LIBS_IN_SHARED</span></tt></dt>
+<dd>By default, shared library linking will ignore any libraries specified with
+the <a class="reference internal" href="#llvmlibs">LLVMLIBS</a> or <a class="reference internal" href="#usedlibs">USEDLIBS</a>. This prevents shared libs from including
+things that will be in the LLVM tool the shared library will be loaded
+into. However, sometimes it is useful to link certain libraries into your
+shared library and this option enables that feature.</dd>
+</dl>
+<dl class="docutils" id="llvmlibs">
+<dt><tt class="docutils literal"><span class="pre">LLVMLIBS</span></tt></dt>
+<dd>Specifies the set of libraries from the LLVM <tt class="docutils literal"><span class="pre">$(ObjDir)</span></tt> that will be
+linked into the tool or library.</dd>
+<dt><tt class="docutils literal"><span class="pre">LOADABLE_MODULE</span></tt></dt>
+<dd>If set to any value, causes the shared library being built to also be a
+loadable module. Loadable modules can be opened with the dlopen() function
+and searched with dlsym (or the operating system’s equivalent). Note that
+setting this variable without also setting <tt class="docutils literal"><span class="pre">SHARED_LIBRARY</span></tt> will have no
+effect.</dd>
+<dt><tt class="docutils literal"><span class="pre">NO_INSTALL</span></tt></dt>
+<dd>Specifies that the build products of the directory should not be installed
+but should be built even if the <tt class="docutils literal"><span class="pre">install</span></tt> target is given.  This is handy
+for directories that build libraries or tools that are only used as part of
+the build process, such as code generators (e.g.  <tt class="docutils literal"><span class="pre">tblgen</span></tt>).</dd>
+<dt><tt class="docutils literal"><span class="pre">OPTIONAL_DIRS</span></tt></dt>
+<dd>Specify a set of directories that may be built, if they exist, but it is
+not an error for them not to exist.</dd>
+<dt><tt class="docutils literal"><span class="pre">PARALLEL_DIRS</span></tt></dt>
+<dd>Specify a set of directories to build recursively and in parallel if the
+<tt class="docutils literal"><span class="pre">-j</span></tt> option was used with <tt class="docutils literal"><span class="pre">make</span></tt>.</dd>
+</dl>
+<dl class="docutils" id="shared-library">
+<dt><tt class="docutils literal"><span class="pre">SHARED_LIBRARY</span></tt></dt>
+<dd>If set to any value, causes a shared library (<tt class="docutils literal"><span class="pre">.so</span></tt>) to be built in
+addition to any other kinds of libraries. Note that this option will cause
+all source files to be built twice: once with options for position
+independent code and once without. Use it only where you really need a
+shared library.</dd>
+<dt><tt class="docutils literal"><span class="pre">SOURCES</span></tt> (optional)</dt>
+<dd>Specifies the list of source files in the current directory to be
+built. Source files of any type may be specified (programs, documentation,
+config files, etc.). If not specified, the makefile system will infer the
+set of source files from the files present in the current directory.</dd>
+<dt><tt class="docutils literal"><span class="pre">SUFFIXES</span></tt></dt>
+<dd>Specifies a set of filename suffixes that occur in suffix match rules.  Only
+set this if your local <tt class="docutils literal"><span class="pre">Makefile</span></tt> specifies additional suffix match
+rules.</dd>
+<dt><tt class="docutils literal"><span class="pre">TARGET</span></tt></dt>
+<dd>Specifies the name of the LLVM code generation target that the current
+directory builds. Setting this variable enables additional rules to build
+<tt class="docutils literal"><span class="pre">.inc</span></tt> files from <tt class="docutils literal"><span class="pre">.td</span></tt> files.</dd>
+</dl>
+<dl class="docutils" id="testsuite">
+<dt><tt class="docutils literal"><span class="pre">TESTSUITE</span></tt></dt>
+<dd>Specifies the directory of tests to run in <tt class="docutils literal"><span class="pre">llvm/test</span></tt>.</dd>
+<dt><tt class="docutils literal"><span class="pre">TOOLNAME</span></tt></dt>
+<dd>Specifies the name of the tool that the current directory should build.</dd>
+<dt><tt class="docutils literal"><span class="pre">TOOL_VERBOSE</span></tt></dt>
+<dd>Implies <tt class="docutils literal"><span class="pre">VERBOSE</span></tt> and also tells each tool invoked to be verbose. This is
+handy when you’re trying to see the sub-tools invoked by each tool invoked
+by the makefile. For example, this will pass <tt class="docutils literal"><span class="pre">-v</span></tt> to the GCC compilers
+which causes it to print out the command lines it uses to invoke sub-tools
+(compiler, assembler, linker).</dd>
+</dl>
+<dl class="docutils" id="usedlibs">
+<dt><tt class="docutils literal"><span class="pre">USEDLIBS</span></tt></dt>
+<dd>Specifies the list of project libraries that will be linked into the tool or
+library.</dd>
+<dt><tt class="docutils literal"><span class="pre">VERBOSE</span></tt></dt>
+<dd>Tells the Makefile system to produce detailed output of what it is doing
+instead of just summary comments. This will generate a LOT of output.</dd>
+</dl>
+</div>
+<div class="section" id="override-variables">
+<h3><a class="toc-backref" href="#id37">Override Variables</a><a class="headerlink" href="#override-variables" title="Permalink to this headline">¶</a></h3>
+<p>Override variables can be used to override the default values provided by the
+LLVM makefile system. These variables can be set in several ways:</p>
+<ul class="simple">
+<li>In the environment (e.g. setenv, export) — not recommended.</li>
+<li>On the <tt class="docutils literal"><span class="pre">make</span></tt> command line — recommended.</li>
+<li>On the <tt class="docutils literal"><span class="pre">configure</span></tt> command line.</li>
+<li>In the Makefile (only <em>after</em> the inclusion of <a class="reference internal" href="#level-makefile-common">$(LEVEL)/Makefile.common</a>).</li>
+</ul>
+<p>The override variables are given below:</p>
+<dl class="docutils">
+<dt><tt class="docutils literal"><span class="pre">AR</span></tt> (defaulted)</dt>
+<dd>Specifies the path to the <tt class="docutils literal"><span class="pre">ar</span></tt> tool.</dd>
+<dt><tt class="docutils literal"><span class="pre">PROJ_OBJ_DIR</span></tt></dt>
+<dd>The directory into which the products of build rules will be placed.  This
+might be the same as <a class="reference internal" href="#proj-src-dir">PROJ_SRC_DIR</a> but typically is not.</dd>
+</dl>
+<dl class="docutils" id="proj-src-dir">
+<dt><tt class="docutils literal"><span class="pre">PROJ_SRC_DIR</span></tt></dt>
+<dd>The directory which contains the source files to be built.</dd>
+<dt><tt class="docutils literal"><span class="pre">BUILD_EXAMPLES</span></tt></dt>
+<dd>If set to 1, build examples in <tt class="docutils literal"><span class="pre">examples</span></tt> and (if building Clang)
+<tt class="docutils literal"><span class="pre">tools/clang/examples</span></tt> directories.</dd>
+<dt><tt class="docutils literal"><span class="pre">BZIP2</span></tt> (configured)</dt>
+<dd>The path to the <tt class="docutils literal"><span class="pre">bzip2</span></tt> tool.</dd>
+<dt><tt class="docutils literal"><span class="pre">CC</span></tt> (configured)</dt>
+<dd>The path to the ‘C’ compiler.</dd>
+<dt><tt class="docutils literal"><span class="pre">CFLAGS</span></tt></dt>
+<dd>Additional flags to be passed to the ‘C’ compiler.</dd>
+<dt><tt class="docutils literal"><span class="pre">CPPFLAGS</span></tt></dt>
+<dd>Additional flags passed to the C/C++ preprocessor.</dd>
+<dt><tt class="docutils literal"><span class="pre">CXX</span></tt></dt>
+<dd>Specifies the path to the C++ compiler.</dd>
+<dt><tt class="docutils literal"><span class="pre">CXXFLAGS</span></tt></dt>
+<dd>Additional flags to be passed to the C++ compiler.</dd>
+<dt><tt class="docutils literal"><span class="pre">DATE</span></tt> (configured)</dt>
+<dd>Specifies the path to the <tt class="docutils literal"><span class="pre">date</span></tt> program or any program that can generate
+the current date and time on its standard output.</dd>
+<dt><tt class="docutils literal"><span class="pre">DOT</span></tt> (configured)</dt>
+<dd>Specifies the path to the <tt class="docutils literal"><span class="pre">dot</span></tt> tool or <tt class="docutils literal"><span class="pre">false</span></tt> if there isn’t one.</dd>
+<dt><tt class="docutils literal"><span class="pre">ECHO</span></tt> (configured)</dt>
+<dd>Specifies the path to the <tt class="docutils literal"><span class="pre">echo</span></tt> tool for printing output.</dd>
+<dt><tt class="docutils literal"><span class="pre">EXEEXT</span></tt> (configured)</dt>
+<dd>Provides the extension to be used on executables built by the makefiles.
+The value may be empty on platforms that do not use file extensions for
+executables (e.g. Unix).</dd>
+<dt><tt class="docutils literal"><span class="pre">INSTALL</span></tt> (configured)</dt>
+<dd>Specifies the path to the <tt class="docutils literal"><span class="pre">install</span></tt> tool.</dd>
+<dt><tt class="docutils literal"><span class="pre">LDFLAGS</span></tt> (configured)</dt>
+<dd>Allows users to specify additional flags to pass to the linker.</dd>
+<dt><tt class="docutils literal"><span class="pre">LIBS</span></tt> (configured)</dt>
+<dd>The list of libraries that should be linked with each tool.</dd>
+<dt><tt class="docutils literal"><span class="pre">LIBTOOL</span></tt> (configured)</dt>
+<dd>Specifies the path to the <tt class="docutils literal"><span class="pre">libtool</span></tt> tool. This tool is renamed <tt class="docutils literal"><span class="pre">mklib</span></tt>
+by the <tt class="docutils literal"><span class="pre">configure</span></tt> script.</dd>
+<dt><tt class="docutils literal"><span class="pre">LLVMAS</span></tt> (defaulted)</dt>
+<dd>Specifies the path to the <tt class="docutils literal"><span class="pre">llvm-as</span></tt> tool.</dd>
+<dt><tt class="docutils literal"><span class="pre">LLVMGCC</span></tt> (defaulted)</dt>
+<dd>Specifies the path to the LLVM version of the GCC ‘C’ Compiler.</dd>
+<dt><tt class="docutils literal"><span class="pre">LLVMGXX</span></tt> (defaulted)</dt>
+<dd>Specifies the path to the LLVM version of the GCC C++ Compiler.</dd>
+<dt><tt class="docutils literal"><span class="pre">LLVMLD</span></tt> (defaulted)</dt>
+<dd>Specifies the path to the LLVM bitcode linker tool</dd>
+<dt><tt class="docutils literal"><span class="pre">LLVM_OBJ_ROOT</span></tt> (configured)</dt>
+<dd>Specifies the top directory into which the output of the build is placed.</dd>
+<dt><tt class="docutils literal"><span class="pre">LLVM_SRC_ROOT</span></tt> (configured)</dt>
+<dd>Specifies the top directory in which the sources are found.</dd>
+<dt><tt class="docutils literal"><span class="pre">LLVM_TARBALL_NAME</span></tt> (configured)</dt>
+<dd>Specifies the name of the distribution tarball to create. This is configured
+from the name of the project and its version number.</dd>
+<dt><tt class="docutils literal"><span class="pre">MKDIR</span></tt> (defaulted)</dt>
+<dd>Specifies the path to the <tt class="docutils literal"><span class="pre">mkdir</span></tt> tool that creates directories.</dd>
+<dt><tt class="docutils literal"><span class="pre">ONLY_TOOLS</span></tt></dt>
+<dd>If set, specifies the list of tools to build.</dd>
+<dt><tt class="docutils literal"><span class="pre">PLATFORMSTRIPOPTS</span></tt></dt>
+<dd>The options to provide to the linker to specify that a stripped (no symbols)
+executable should be built.</dd>
+<dt><tt class="docutils literal"><span class="pre">RANLIB</span></tt> (defaulted)</dt>
+<dd>Specifies the path to the <tt class="docutils literal"><span class="pre">ranlib</span></tt> tool.</dd>
+<dt><tt class="docutils literal"><span class="pre">RM</span></tt> (defaulted)</dt>
+<dd>Specifies the path to the <tt class="docutils literal"><span class="pre">rm</span></tt> tool.</dd>
+<dt><tt class="docutils literal"><span class="pre">SED</span></tt> (defaulted)</dt>
+<dd>Specifies the path to the <tt class="docutils literal"><span class="pre">sed</span></tt> tool.</dd>
+<dt><tt class="docutils literal"><span class="pre">SHLIBEXT</span></tt> (configured)</dt>
+<dd>Provides the filename extension to use for shared libraries.</dd>
+<dt><tt class="docutils literal"><span class="pre">TBLGEN</span></tt> (defaulted)</dt>
+<dd>Specifies the path to the <tt class="docutils literal"><span class="pre">tblgen</span></tt> tool.</dd>
+<dt><tt class="docutils literal"><span class="pre">TAR</span></tt> (defaulted)</dt>
+<dd>Specifies the path to the <tt class="docutils literal"><span class="pre">tar</span></tt> tool.</dd>
+<dt><tt class="docutils literal"><span class="pre">ZIP</span></tt> (defaulted)</dt>
+<dd>Specifies the path to the <tt class="docutils literal"><span class="pre">zip</span></tt> tool.</dd>
+</dl>
+</div>
+<div class="section" id="readable-variables">
+<h3><a class="toc-backref" href="#id38">Readable Variables</a><a class="headerlink" href="#readable-variables" title="Permalink to this headline">¶</a></h3>
+<p>Variables listed in the table below can be used by the user’s Makefile but
+should not be changed. Changing the value will generally cause the build to go
+wrong, so don’t do it.</p>
+<dl class="docutils">
+<dt><tt class="docutils literal"><span class="pre">bindir</span></tt></dt>
+<dd>The directory into which executables will ultimately be installed. This
+value is derived from the <tt class="docutils literal"><span class="pre">--prefix</span></tt> option given to <tt class="docutils literal"><span class="pre">configure</span></tt>.</dd>
+<dt><tt class="docutils literal"><span class="pre">BuildMode</span></tt></dt>
+<dd>The name of the type of build being performed: Debug, Release, or
+Profile.</dd>
+<dt><tt class="docutils literal"><span class="pre">bytecode_libdir</span></tt></dt>
+<dd>The directory into which bitcode libraries will ultimately be installed.
+This value is derived from the <tt class="docutils literal"><span class="pre">--prefix</span></tt> option given to <tt class="docutils literal"><span class="pre">configure</span></tt>.</dd>
+<dt><tt class="docutils literal"><span class="pre">ConfigureScriptFLAGS</span></tt></dt>
+<dd>Additional flags given to the <tt class="docutils literal"><span class="pre">configure</span></tt> script when reconfiguring.</dd>
+<dt><tt class="docutils literal"><span class="pre">DistDir</span></tt></dt>
+<dd>The <em>current</em> directory for which a distribution copy is being made.</dd>
+</dl>
+<dl class="docutils" id="echo">
+<dt><tt class="docutils literal"><span class="pre">Echo</span></tt></dt>
+<dd>The LLVM Makefile System output command. This provides the <tt class="docutils literal"><span class="pre">llvm[n]</span></tt>
+prefix and starts with <tt class="docutils literal"><span class="pre">@</span></tt> so the command itself is not printed by
+<tt class="docutils literal"><span class="pre">make</span></tt>.</dd>
+<dt><tt class="docutils literal"><span class="pre">EchoCmd</span></tt></dt>
+<dd>Same as <a class="reference internal" href="#echo">Echo</a> but without the leading <tt class="docutils literal"><span class="pre">@</span></tt>.</dd>
+<dt><tt class="docutils literal"><span class="pre">includedir</span></tt></dt>
+<dd>The directory into which include files will ultimately be installed.  This
+value is derived from the <tt class="docutils literal"><span class="pre">--prefix</span></tt> option given to <tt class="docutils literal"><span class="pre">configure</span></tt>.</dd>
+<dt><tt class="docutils literal"><span class="pre">libdir</span></tt></dt>
+<dd>The directory into which native libraries will ultimately be installed.
+This value is derived from the <tt class="docutils literal"><span class="pre">--prefix</span></tt> option given to
+<tt class="docutils literal"><span class="pre">configure</span></tt>.</dd>
+<dt><tt class="docutils literal"><span class="pre">LibDir</span></tt></dt>
+<dd>The configuration specific directory into which libraries are placed before
+installation.</dd>
+<dt><tt class="docutils literal"><span class="pre">MakefileConfig</span></tt></dt>
+<dd>Full path of the <tt class="docutils literal"><span class="pre">Makefile.config</span></tt> file.</dd>
+<dt><tt class="docutils literal"><span class="pre">MakefileConfigIn</span></tt></dt>
+<dd>Full path of the <tt class="docutils literal"><span class="pre">Makefile.config.in</span></tt> file.</dd>
+<dt><tt class="docutils literal"><span class="pre">ObjDir</span></tt></dt>
+<dd>The configuration and directory specific directory where build objects
+(compilation results) are placed.</dd>
+<dt><tt class="docutils literal"><span class="pre">SubDirs</span></tt></dt>
+<dd>The complete list of sub-directories of the current directory as
+specified by other variables.</dd>
+<dt><tt class="docutils literal"><span class="pre">Sources</span></tt></dt>
+<dd>The complete list of source files.</dd>
+<dt><tt class="docutils literal"><span class="pre">sysconfdir</span></tt></dt>
+<dd>The directory into which configuration files will ultimately be
+installed. This value is derived from the <tt class="docutils literal"><span class="pre">--prefix</span></tt> option given to
+<tt class="docutils literal"><span class="pre">configure</span></tt>.</dd>
+<dt><tt class="docutils literal"><span class="pre">ToolDir</span></tt></dt>
+<dd>The configuration specific directory into which executables are placed
+before they are installed.</dd>
+<dt><tt class="docutils literal"><span class="pre">TopDistDir</span></tt></dt>
+<dd>The top most directory into which the distribution files are copied.</dd>
+<dt><tt class="docutils literal"><span class="pre">Verb</span></tt></dt>
+<dd>Use this as the first thing on your build script lines to enable or disable
+verbose mode. It expands to either an <tt class="docutils literal"><span class="pre">@</span></tt> (quiet mode) or nothing (verbose
+mode).</dd>
+</dl>
+</div>
+<div class="section" id="internal-variables">
+<h3><a class="toc-backref" href="#id39">Internal Variables</a><a class="headerlink" href="#internal-variables" title="Permalink to this headline">¶</a></h3>
+<p>Variables listed below are used by the LLVM Makefile System and considered
+internal. You should not use these variables under any circumstances.</p>
+<div class="highlight-makefile"><div class="highlight"><pre>Archive
+AR.Flags
+BaseNameSources
+BCLinkLib
+C.Flags
+Compile.C
+CompileCommonOpts
+Compile.CXX
+ConfigStatusScript
+ConfigureScript
+CPP.Flags
+CPP.Flags
+CXX.Flags
+DependFiles
+DestArchiveLib
+DestBitcodeLib
+DestModule
+DestSharedLib
+DestTool
+DistAlways
+DistCheckDir
+DistCheckTop
+DistFiles
+DistName
+DistOther
+DistSources
+DistSubDirs
+DistTarBZ2
+DistTarGZip
+DistZip
+ExtraLibs
+FakeSources
+INCFiles
+InternalTargets
+LD.Flags
+LibName.A
+LibName.BC
+LibName.LA
+LibName.O
+LibTool.Flags
+Link
+LinkModule
+LLVMLibDir
+LLVMLibsOptions
+LLVMLibsPaths
+LLVMToolDir
+LLVMUsedLibs
+LocalTargets
+Module
+ObjectsLO
+ObjectsO
+ObjMakefiles
+ParallelTargets
+PreConditions
+ProjLibsOptions
+ProjLibsPaths
+ProjUsedLibs
+Ranlib
+RecursiveTargets
+SrcMakefiles
+Strip
+StripWarnMsg
+TableGen
+TDFiles
+ToolBuildPath
+TopLevelTargets
+UserTargets
+</pre></div>
+</div>
+</div>
+</div>
+</div>
+
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@@ -0,0 +1,169 @@
+
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+            
+  <div class="section" id="llvm-s-optional-rich-disassembly-output">
+<h1>LLVM’s Optional Rich Disassembly Output<a class="headerlink" href="#llvm-s-optional-rich-disassembly-output" title="Permalink to this headline">¶</a></h1>
+<div class="contents local topic" id="contents">
+<ul class="simple">
+<li><a class="reference internal" href="#introduction" id="id2">Introduction</a></li>
+<li><a class="reference internal" href="#instruction-annotations" id="id3">Instruction Annotations</a><ul>
+<li><a class="reference internal" href="#contextual-markups" id="id4">Contextual markups</a></li>
+<li><a class="reference internal" href="#c-api-details" id="id5">C API Details</a></li>
+</ul>
+</li>
+</ul>
+</div>
+<div class="section" id="introduction">
+<h2><a class="toc-backref" href="#id2">Introduction</a><a class="headerlink" href="#introduction" title="Permalink to this headline">¶</a></h2>
+<p>LLVM’s default disassembly output is raw text. To allow consumers more ability
+to introspect the instructions’ textual representation or to reformat for a more
+user friendly display there is an optional rich disassembly output.</p>
+<p>This optional output is sufficient to reference into individual portions of the
+instruction text. This is intended for clients like disassemblers, list file
+generators, and pretty-printers, which need more than the raw instructions and
+the ability to print them.</p>
+<p>To provide this functionality the assembly text is marked up with annotations.
+The markup is simple enough in syntax to be robust even in the case of version
+mismatches between consumers and producers. That is, the syntax generally does
+not carry semantics beyond “this text has an annotation,” so consumers can
+simply ignore annotations they do not understand or do not care about.</p>
+<p>After calling <tt class="docutils literal"><span class="pre">LLVMCreateDisasm()</span></tt> to create a disassembler context the
+optional output is enable with this call:</p>
+<div class="highlight-c"><div class="highlight"><pre><span class="n">LLVMSetDisasmOptions</span><span class="p">(</span><span class="n">DC</span><span class="p">,</span> <span class="n">LLVMDisassembler_Option_UseMarkup</span><span class="p">);</span>
+</pre></div>
+</div>
+<p>Then subsequent calls to <tt class="docutils literal"><span class="pre">LLVMDisasmInstruction()</span></tt> will return output strings
+with the marked up annotations.</p>
+</div>
+<div class="section" id="instruction-annotations">
+<h2><a class="toc-backref" href="#id3">Instruction Annotations</a><a class="headerlink" href="#instruction-annotations" title="Permalink to this headline">¶</a></h2>
+<div class="section" id="contextual-markups">
+<span id="id1"></span><h3><a class="toc-backref" href="#id4">Contextual markups</a><a class="headerlink" href="#contextual-markups" title="Permalink to this headline">¶</a></h3>
+<p>Annoated assembly display will supply contextual markup to help clients more
+efficiently implement things like pretty printers. Most markup will be target
+independent, so clients can effectively provide good display without any target
+specific knowledge.</p>
+<p>Annotated assembly goes through the normal instruction printer, but optionally
+includes contextual tags on portions of the instruction string. An annotation
+is any ‘<’ ‘>’ delimited section of text(1).</p>
+<div class="highlight-bat"><div class="highlight"><pre>annotation: <span class="s1">'<'</span> tag-name tag-modifier-list <span class="s1">':'</span> annotated-text <span class="s1">'>'</span>
+tag-name: identifier
+tag-modifier-list: comma delimited identifier list
+</pre></div>
+</div>
+<p>The tag-name is an identifier which gives the type of the annotation. For the
+first pass, this will be very simple, with memory references, registers, and
+immediates having the tag names “mem”, “reg”, and “imm”, respectively.</p>
+<p>The tag-modifier-list is typically additional target-specific context, such as
+register class.</p>
+<p>Clients should accept and ignore any tag-names or tag-modifiers they do not
+understand, allowing the annotations to grow in richness without breaking older
+clients.</p>
+<p>For example, a possible annotation of an ARM load of a stack-relative location
+might be annotated as:</p>
+<div class="highlight-nasm"><div class="highlight"><pre>ldr <reg gpr:r0>, <mem regoffset:[<reg gpr:sp>, <imm:#4>]>
+</pre></div>
+</div>
+<p>1: For assembly dialects in which ‘<’ and/or ‘>’ are legal tokens, a literal token is escaped by following immediately with a repeat of the character.  For example, a literal ‘<’ character is output as ‘<<’ in an annotated assembly string.</p>
+</div>
+<div class="section" id="c-api-details">
+<h3><a class="toc-backref" href="#id5">C API Details</a><a class="headerlink" href="#c-api-details" title="Permalink to this headline">¶</a></h3>
+<p>The intended consumers of this information use the C API, therefore the new C
+API function for the disassembler will be added to provide an option to produce
+disassembled instructions with annotations, <tt class="docutils literal"><span class="pre">LLVMSetDisasmOptions()</span></tt> and the
+<tt class="docutils literal"><span class="pre">LLVMDisassembler_Option_UseMarkup</span></tt> option (see above).</p>
+</div>
+</div>
+</div>
+
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+    </div>
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+             >index</a></li>
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