Avoid creating a redundant zero APInt.

[oota-llvm.git] / docs / AliasAnalysis.html

diff --git a/docs/AliasAnalysis.html b/docs/AliasAnalysis.html
index 63567876e377b1d0c01410116f5fe0dfd2cadd5d..6663f0caa75fb1d7f1a4b49ca24c8225872677fa 100644 (file)
--- a/docs/AliasAnalysis.html
+++ b/docs/AliasAnalysis.html
@@ -50,6 +50,7 @@
     implementations</a></li>
     </ul>
   </li>
+  <li><a href="#memdep">Memory Dependence Analysis</a></li>
 </ol>
 
 <div class="doc_author">
@@ -70,7 +71,7 @@ memory.  There are many different algorithms for alias analysis and many
 different ways of classifying them: flow-sensitive vs flow-insensitive,
 context-sensitive vs context-insensitive, field-sensitive vs field-insensitive,
 unification-based vs subset-based, etc.  Traditionally, alias analyses respond
-to a query with a <a href="#MustNoMay">Must, May, or No</a> alias response,
+to a query with a <a href="#MustMayNo">Must, May, or No</a> alias response,
 indicating that two pointers always point to the same object, might point to the
 same object, or are known to never point to the same object.</p>
 
@@ -755,6 +756,9 @@ field-<b>sensitive</b>" version of Steensgaard's algorithm using the Data
 Structure Analysis framework.  This gives it substantially more precision than
 the standard algorithm while maintaining excellent analysis scalability.</p>
 
+<p>Note that <tt>-steens-aa</tt> is available in the optional "poolalloc"
+module, it is not part of the LLVM core.</p>
+
 </div>
 
 <!-- _______________________________________________________________________ -->
@@ -775,6 +779,9 @@ queries, and can provide context-sensitive mod/ref information as well.  The
 only major facility not implemented so far is support for must-alias
 information.</p>
 
+<p>Note that <tt>-ds-aa</tt> is available in the optional "poolalloc"
+module, it is not part of the LLVM core.</p>
+
 </div>
 
 
@@ -941,6 +948,24 @@ algorithm will have a lower number of may aliases).</p>
 
 </div>
 
+<!-- *********************************************************************** -->
+<div class="doc_section">
+  <a name="memdep">Memory Dependence Analysis</a>
+</div>
+<!-- *********************************************************************** -->
+
+<div class="doc_text">
+
+<p>If you're just looking to be a client of alias analysis information, consider
+using the Memory Dependence Analysis interface instead.  MemDep is a lazy, 
+caching layer on top of alias analysis that is able to answer the question of
+what preceding memory operations a given instruction depends on, either at an
+intra- or inter-block level.  Because of its laziness and caching 
+policy, using MemDep can be a significant performance win over accessing alias
+analysis directly.</p>
+
+</div>
+
 <!-- *********************************************************************** -->
 
 <hr>