[llvm-commits] [llvm] r90116 - /llvm/trunk/docs/LangRef.html

[Eric Christopher]

Author: echristo
Date: Mon Nov 30 02:03:53 2009
New Revision: 90116

URL: http://llvm.org/viewvc/llvm-project?rev=90116&view=rev
Log:
First pass at llvm.objectsize documentation.

Modified:
    llvm/trunk/docs/LangRef.html

Modified: llvm/trunk/docs/LangRef.html
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/LangRef.html?rev=90116&r1=90115&r2=90116&view=diff

==============================================================================
--- llvm/trunk/docs/LangRef.html (original)
+++ llvm/trunk/docs/LangRef.html Mon Nov 30 02:03:53 2009
@@ -291,6 +291,8 @@
             '<tt>llvm.trap</tt>' Intrinsic</a></li>
           <li><a href="#int_stackprotector">
             '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
+	  <li><a href="#int_objectsize">
+            '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
         </ol>
       </li>
     </ol>
@@ -7246,6 +7248,41 @@
 
 </div>
 
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+  <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+  declare i32 @llvm.objectsize.i32( i8* <ptr>, i32 <type> )
+  declare i64 @llvm.objectsize.i64( i8* <ptr>, i32 <type> )
+</pre>
+
+<h5>Overview:</h5>
+<p>The <tt>llvm.objectsize</tt> intrinsic returns the constant number of bytes
+   from <tt>ptr</tt> to the end of the object <tt>ptr</tt> points to if it
+   can deduce this at compile time.  If there are any side-effects in evaluating
+   the argument or it cannot deduce which objects <tt>ptr</tt> points to at compile
+   time the intrinsic returns <tt>(size_t) -1</tt> for <tt>type</tt> 0
+   or 1 and <tt>(size_t) 0</tt> for <tt>type</tt> 2 or 3.</p>
+
+<h5>Arguments:</h5>
+<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments.  The first
+   argument is a pointer to the object <tt>ptr</tt> and an integer <tt>type</tt>.
+   <tt>type</tt> is an integer ranging from 0 to 3. The lsb corresponds to
+   a return value based on whole objects, the second bit whether or not we
+   return the maximum or minimum remaining bytes computed.</p>
+
+<h5>Semantics:</h5>
+<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
+   representing the size of the object concerned or <tt>(size_t) -1</tt> if
+   it cannot be determined at compile time.</p>
+
+</div>
+
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