[llvm-commits] CVS: llvm/docs/LangRef.html
Chris Lattner
lattner at cs.uiuc.edu
Mon Feb 28 11:24:35 PST 2005
Changes in directory llvm/docs:
LangRef.html updated: 1.85 -> 1.86
---
Log message:
Document llvm.prefetch, patch contributed by Justin Wick!
---
Diffs of the changes: (+48 -1)
LangRef.html | 49 ++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 48 insertions(+), 1 deletion(-)
Index: llvm/docs/LangRef.html
diff -u llvm/docs/LangRef.html:1.85 llvm/docs/LangRef.html:1.86
--- llvm/docs/LangRef.html:1.85 Fri Feb 18 20:22:14 2005
+++ llvm/docs/LangRef.html Mon Feb 28 13:24:19 2005
@@ -125,6 +125,7 @@
<ol>
<li><a href="#i_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
<li><a href="#i_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
+ <li><a href="#i_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
</ol>
</li>
<li><a href="#int_os">Operating System Intrinsics</a>
@@ -2499,6 +2500,52 @@
</p>
</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+ call void (sbyte *, uint, uint)* %llvm.prefetch(sbyte * <address>,
+ uint <rw>,
+ uint <locality>)
+</pre>
+
+<h5>Overview:</h5>
+
+
+<p>
+The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
+a prefetch instruction if supported, otherwise it is a noop. Prefetches have no
+behavior affect on the program, but can change the performance characteristics
+of the code.
+</p>
+
+<h5>Arguments:</h5>
+
+<p>
+<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
+determining if the fetch should be for a read (0) or write (1), and
+<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
+locality, to (3) - exteremely local keep in cache. The <tt>rw</tt> and
+<tt>locality</tt> arguments must be constant integers.
+</p>
+
+<h5>Semantics:</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 class="doc_subsection">
<a name="int_os">Operating System Intrinsics</a>
@@ -2924,7 +2971,7 @@
<a href="mailto:sabre at nondot.org">Chris Lattner</a><br>
<a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
- Last modified: $Date: 2005/02/19 02:22:14 $
+ Last modified: $Date: 2005/02/28 19:24:19 $
</address>
</body>
</html>
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