[llvm-commits] [llvm] r101987 - /llvm/trunk/docs/ReleaseNotes.html
Chris Lattner
sabre at nondot.org
Tue Apr 20 22:17:40 PDT 2010
Author: lattner
Date: Wed Apr 21 00:17:40 2010
New Revision: 101987
URL: http://llvm.org/viewvc/llvm-project?rev=101987&view=rev
Log:
rough pass moving stuff into relevant sections, still much
editing to do.
Modified:
llvm/trunk/docs/ReleaseNotes.html
Modified: llvm/trunk/docs/ReleaseNotes.html
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/ReleaseNotes.html?rev=101987&r1=101986&r2=101987&view=diff
==============================================================================
--- llvm/trunk/docs/ReleaseNotes.html (original)
+++ llvm/trunk/docs/ReleaseNotes.html Wed Apr 21 00:17:40 2010
@@ -60,10 +60,6 @@
current one. To see the release notes for a specific release, please see the
<a href="http://llvm.org/releases/">releases page</a>.</p>
-
-<p>FIXME: llvm.org moved to new server, mention new logo, Ted and Doug new code
- owners, web page in llvm-www repos.</p>
-
</div>
@@ -79,14 +75,9 @@
<!-- Features that need text if they're finished for 2.7:
- gcc plugin.
strong phi elim
- variable debug info for optimized code
- postalloc scheduler: anti dependence breaking, hazard recognizer?
- metadata
+ llvm.dbg.value: variable debug info for optimized code
loop dependence analysis
- ELF Writer? How stable?
- <li>PostRA scheduler improvements, ARM adoption (David Goodwin).</li>
-->
<!-- for announcement email:
@@ -216,7 +207,8 @@
<p>
All of the code in the compiler-rt project is available under the standard LLVM
-License, a "BSD-style" license.</p>
+License, a "BSD-style" license. New in LLVM 2.7: compiler_rt now
+supports ARM targets.</p>
</div>
@@ -381,6 +373,24 @@
in this section.
</p>
+<p>In addition to changes to the code, between LLVM 2.6 and 2.7, a number of
+organization changes have happened:
+</p>
+
+<ul>
+<li>LLVM has a new <a href="http://llvm.org/Logo.html">official Logo</a>!</li>
+
+<li><a href="http://llvm.org">llvm.org</a> is now hosted on a new (and much
+faster) server. It is still hosted as the University of Illinois.</li>
+
+<li>Ted Kremenek and Doug Gregor have stepped forward as <a
+ href="http://llvm.org/docs/DeveloperPolicy.html#owners">Code Owners</a> of the
+ Clang static analyzer and the Clang Frontend, respectively.</li>
+
+<li>The LLVM web pages are now checked into the SVN server, in the "www",
+ "www-pubs" and "www-releases" SVN modules. Previously they were hidden in a
+ largely inaccessible old CVS server.</p>
+</ul>
</div>
<!--=========================================================================-->
@@ -393,87 +403,25 @@
<p>LLVM 2.7 includes several major new capabilities:</p>
<ul>
-<li>...</li>
-</ul>
+<li>New MicroBlaze backend. http://en.wikipedia.org/wiki/MicroBlaze</li>
-Extensible metadata solid.
+<li>Extensible metadata solid.</li>
-Debug info improvements: using metadata instead of llvm.dbg global variables.
-This brings several enhancements including improved compile times.
+<li>Debug info improvements: using metadata instead of llvm.dbg global variables.
+This brings several enhancements including improved compile times.</li>
-New instruction selector.
-GHC Haskell ABI/ calling conv support.
-Pre-Alpha support for unions in IR.
-New InlineHint and StackAlignment function attributes
-Code generator MC'ized except for debug info and EH.
-New SCEV AA pass: -scev-aa
-Inliner reuses arrays allocas when inlining multiple callers to reduce stack usage.
+<li>Indirect branch + address of label (blog post), particularly useful for
+interpreters.</li>
+
+<li>New instruction selector.</li>
+
+</ul>
+libllvm2.7.so?? configure with --enable-shared
MC encoding and disassembler apis.
-Optimal Edge Profiling?
-Instcombine is now a library, has its own IRBuilder to simplify itself.
-New llvm/Support/Regex.h API. FileCheck now does regex's
-Many subtle pointer invalidation bugs in Callgraph have been fixed and it now uses asserting value handles.
MC Disassembler (with blog post), MCInstPrinter. Many X86 backend and AsmPrinter simplifications
-Various tools like llc and opt now read either .ll or .bc files as input.
-Malloc and free instructions got removed, along with LowerAllocations pass.
-compiler-rt support for ARM.
-completely llvm-gcc NEON support.
Can transcode from GAS to intel syntax with "llvm-mc foo.s -output-asm-variant=1"
-JIT debug information with GDB 7.0
-New CodeGen Level CSE
-CMake can now run tests, what other improvements?
-ARM/Thumb using reg scavenging for stack object address materialization (PEI).
-New SSAUpdater and MachineSSAUpdater classes for unstructured ssa updating,
- changed jump threading, GVN, etc to use it which simplified them and speed
- them up.
-Combiner-AA improvements, why not on by default?
-Pre-regalloc tail duplication
-x86 sibcall / tailcall optimization in CCC mode.
-New LSR with "full strength reduction" mode. Description?
-Codegen level OptimizeExtsPass pass, takes advantage of x86 subregs.
-Better code size analysis in loop unswitch, inliner code split out to a new
- CodeMetrics class for reuse.
-The ARM backend now has good support for ARMv4 backend (tested on StrongARM
- hardware), previously only supported ARMv4T and newer.
-Half-float support in APFloat
-Indirect branch + address of label (blog post), particularly useful for interpreters.
-Many changes to the pass ordering for improved optimization effectiveness.
-BasicAA improved to be less dependent on "type safe" pointers, it can now look
- through bitcasts more aggressively.
-GVN PHI Translation improvements. blog post: http://blog.llvm.org/2009/12/advanced-topics-in-redundant-load.html
-llvm.objectsize.
-MachineSSAUpdater.h
-PostRA scheduler for X86?
-llvm.dbg.value, not being used by default though, more in 2.8. Many improvements to debug info
-Support for the GCC option -fno-schedule-insns
-non-temporal load/store
-libllvm2.7.so?? configure with --enable-shared
-dbgs() and -debug-buffer-size=N
-New MicroBlaze backend. http://en.wikipedia.org/wiki/MicroBlaze
-XMM subreg modeling for extraction of the low element.
-Opt now works conservatively if no target data is set (is this fully working?)
-Target data now has notion of 'native' integer data types which optimizations can use.
-ARM backend generates instructions in unified assembly syntax.
-New Analysis/InstructionSimplify.h interface for simplifying instructions that don't exist.
-Jump threading is now much more aggressive at simplifying correlated
- conditionals and threading blocks with otherwise complex logic. CondProp pass
- removed (functionality merged into jump threading).
-X86 and XCore supports returning arbitrary return values, returning too many values is
- supported by returning through a hidden pointer.
-verbose-asm now produces information about spill slots and loop nests
-
-
-Defaults to RTTI off (smaller code size!), packagers should build with make REQUIRE_RTTI=1.
-AndersAA got removed
-PredSimplify, LoopVR, GVNPRE, RSProfiling (random sampling profiling) got removed.
-LLVM command line tools now overwrite their output, before they would only do this with -f.
-DOUT removed, use DEBUG(errs() instead.
-Much stuff converted to use raw_ostream instead of std::ostream.
-TargetAsmInfo renamed to MCAsmInfo
-llvm/ADT/iterator.h gone.
-
</div>
@@ -487,7 +435,13 @@
expose new optimization opportunities:</p>
<ul>
-<li>...</li>
+<li>New InlineHint and StackAlignment function attributes
+Half-float support in APFloat
+llvm.objectsize.
+New llvm/Support/Regex.h API. FileCheck now does regex's
+Pre-Alpha support for unions in IR.
+dbgs() and -debug-buffer-size=N
+</li>
</ul>
</div>
@@ -505,10 +459,28 @@
<ul>
<li>...</li>
+Inliner reuses arrays allocas when inlining multiple callers to reduce stack usage.
+Optimal Edge Profiling?
+Instcombine is now a library, has its own IRBuilder to simplify itself.
+Better code size analysis in loop unswitch, inliner code split out to a new
+ CodeMetrics class for reuse.
+Many changes to the pass ordering for improved optimization effectiveness.
+BasicAA improved to be less dependent on "type safe" pointers, it can now look
+ through bitcasts more aggressively.
+GVN PHI Translation improvements. blog post: http://blog.llvm.org/2009/12/advanced-topics-in-redundant-load.html
+New SCEV AA pass: -scev-aa
+Target data now has notion of 'native' integer data types which optimizations can use.
+Opt now works conservatively if no target data is set (is this fully working?)
+New Analysis/InstructionSimplify.h interface for simplifying instructions that don't exist.
+Jump threading is now much more aggressive at simplifying correlated
+ conditionals and threading blocks with otherwise complex logic. CondProp pass
+ removed (functionality merged into jump threading).
+New SSAUpdater and MachineSSAUpdater classes for unstructured ssa updating,
+ changed jump threading, GVN, etc to use it which simplified them and speed
+ them up.
-</ul>
-<p>Also, -anders-aa was removed</p>
+</ul>
</div>
@@ -521,15 +493,21 @@
<div class="doc_text">
<ul>
+<li>The JIT now supports generating debug information, which is compatible with
+the new GDB 7.0 (and later) interfaces for registering debug info for
+dynamically generated code.</li>
+
<li>The JIT now <a
href="http://llvm.org/viewvc/llvm-project?view=rev&revision=85295">defaults
to compiling eagerly</a> to avoid a race condition in the lazy JIT.
Clients that still want the lazy JIT can switch it on by calling
<tt>ExecutionEngine::DisableLazyCompilation(false)</tt>.</li>
+
<li>It is now possible to create more than one JIT instance in the same process.
These JITs can generate machine code in parallel,
although <a href="http://llvm.org/docs/ProgrammersManual.html#jitthreading">you
still have to obey the other threading restrictions</a>.</li>
+
</ul>
</div>
@@ -547,45 +525,42 @@
<ul>
-<li>...</li>
-</ul>
-</div>
-
-<!--=========================================================================-->
-<div class="doc_subsection">
-<a name="x86">X86-32 and X86-64 Target Improvements</a>
-</div>
+Code generator MC'ized except for debug info and EH.
-<div class="doc_text">
-<p>New features of the X86 target include:
-</p>
+New CodeGen Level CSE
+Combiner-AA improvements, why not on by default?
+Pre-regalloc tail duplication
+New LSR with "full strength reduction" mode. Description?
+Codegen level OptimizeExtsPass pass, takes advantage of x86 subregs.
+Support for the GCC option -fno-schedule-insns
+non-temporal load/store
+MachineSSAUpdater.h
+X86 and XCore supports returning arbitrary return values, returning too many values is
+ supported by returning through a hidden pointer.
+verbose-asm now produces information about spill slots and loop nests
+GHC Haskell ABI / calling conv support.
+Many improvements to debug info
-<ul>
<li>...</li>
-
</ul>
-
</div>
<!--=========================================================================-->
<div class="doc_subsection">
-<a name="pic16">PIC16 Target Improvements</a>
+<a name="x86">X86-32 and X86-64 Target Improvements</a>
</div>
<div class="doc_text">
-<p>New features of the PIC16 target include:
+<p>New features of the X86 target include:
</p>
<ul>
-<li>...</li>
-</ul>
-<p>Things not yet supported:</p>
+<li>PostRA scheduler for X86?</li>
+<li>x86 sibcall / tailcall optimization in CCC mode.</li>
+<li>X86: XMM subreg modeling for extraction of the low element.</li>
-<ul>
-<li>Variable arguments.</li>
-<li>Interrupts/programs.</li>
</ul>
</div>
@@ -601,7 +576,12 @@
<ul>
-<li>...</li>
+<li>complete llvm-gcc NEON support.</li>
+<li>ARM/Thumb using reg scavenging for stack object address materialization
+ (PEI).</li>
+<li>The ARM backend now has good support for ARMv4 backend (tested on StrongARM
+ hardware), previously only supported ARMv4T and newer.</li>
+<li>ARM backend generates instructions in unified assembly syntax.</li>
</ul>
@@ -649,7 +629,13 @@
<p>Other miscellaneous features include:</p>
<ul>
-<li>...</li>
+<li>LLVM command line tools now overwrite their output by default, before they
+ would only do this with -f. This makes them more convenient to use, and
+ behave more like standard unix tools.</li>
+
+<li>The opt and llc tools now autodetect whether their input is a .ll or .bc
+ file, and automatically do the right thing. This means you don't need to
+ explicitly use the llvm-as tool for most things.</li>
</ul>
</div>
@@ -667,18 +653,45 @@
from the previous release.</p>
<ul>
+
+<li>
+The Andersen's alias analysis ("anders-aa") pass, the Predicate Simplifier
+("predsimplify") pass, the LoopVR pass, the GVNPRE pass, and the random sampling
+profiling ("rsprofiling") passes have all been removed. They were not being
+actively maintained and had substantial problems. If you are interested in
+these components, you are welcome to ressurect them from SVN, fix the
+correctness problems, and resubmit them to mainline.</li>
+
+<li>LLVM now defaults to building most libraries with RTTI turned off, providing
+a code size reduction. Packagers who are interested in building LLVM to support
+plugins that require RTTI information should build with "make REQUIRE_RTTI=1"
+and should read the new <a href="Packaging.html">Advice on Packaging LLVM</a>
+document.</li>
+
<li>The LLVM interpreter now defaults to <em>not</em> using <tt>libffi</tt> even
if you have it installed. This makes it more likely that an LLVM built on one
system will work when copied to a similar system. To use <tt>libffi</tt>,
-configure with <tt>--enable-libffi</tt>.
-</li>
-</ul>
+configure with <tt>--enable-libffi</tt></li>.
+<li>Debug information uses a completely different representation, an LLVM 2.6
+.bc file should work with LLVM 2.7, but debug info won't come forward.</li>
+
+<li>The LLVM 2.6 (and earlier) "malloc" and "free" instructions got removed,
+ along with LowerAllocations pass. Now you should just use a call to the
+ malloc and free functions in libc. These calls are optimized as well as
+ the old instructions were.</li>
+</ul>
<p>In addition, many APIs have changed in this release. Some of the major LLVM
API changes are:</p>
<ul>
+<li>Just about everything has been converted to use raw_ostream instead of
+ std::ostream.</li>
+<li>llvm/ADT/iterator.h has been removed, just use <iterator>
+ instead.</li>
+<li>The Streams.h file and "DOUT" got removed, use "DEBUG(errs() << ...);"
+ instead.</li>
<li><tt>ModuleProvider</tt> has been <a
href="http://llvm.org/viewvc/llvm-project?view=rev&revision=94686">removed</a>
and its methods moved to <tt>Module</tt> and <tt>GlobalValue</tt>.
@@ -698,8 +711,6 @@
<tt>GlobalValue::hasNotBeenReadFromBitcode</tt> with
<tt>GlobalValue::isMaterializable</tt>.</li>
-<li>FIXME: Debug info has been totally redone. Add pointers to new APIs. Substantial caveats about compatibility of .ll and .bc files.</li>
-
<li>The <tt>llvm/Support/DataTypes.h</tt> header has moved
to <tt>llvm/System/DataTypes.h</tt>.</li>
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