[llvm-commits] CVS: llvm/docs/WritingAnLLVMPass.html

[Devang Patel]

Changes in directory llvm/docs:

WritingAnLLVMPass.html updated: 1.54 -> 1.55
---
Log message:

Document how, module pass can require function pass.


---
Diffs of the changes:  (+19 -3)

 WritingAnLLVMPass.html |   22 +++++++++++++++++++---
 1 files changed, 19 insertions(+), 3 deletions(-)


Index: llvm/docs/WritingAnLLVMPass.html
diff -u llvm/docs/WritingAnLLVMPass.html:1.54 llvm/docs/WritingAnLLVMPass.html:1.55
--- llvm/docs/WritingAnLLVMPass.html:1.54	Mon Mar 19 17:21:25 2007
+++ llvm/docs/WritingAnLLVMPass.html	Mon Apr 16 16:28:14 2007
@@ -466,7 +466,9 @@
 <tt>ModulePass</tt> indicates that your pass uses the entire program as a unit,
 refering to function bodies in no predictable order, or adding and removing
 functions.  Because nothing is known about the behavior of <tt>ModulePass</tt>
-subclasses, no optimization can be done for their execution.</p>
+subclasses, no optimization can be done for their execution. A module pass
+can use function level passes (e.g. dominators) using getAnalysis interface
+<tt> getAnalysis<DominatorTree>(Function)</tt>. </p> 
 
 <p>To write a correct <tt>ModulePass</tt> subclass, derive from
 <tt>ModulePass</tt> and overload the <tt>runOnModule</tt> method with the
@@ -1127,7 +1129,21 @@
 declare as required in your <a
 href="#getAnalysisUsage"><tt>getAnalysisUsage</tt></a> implementation.  This
 method can be called by your <tt>run*</tt> method implementation, or by any
-other local method invoked by your <tt>run*</tt> method.</p>
+other local method invoked by your <tt>run*</tt> method.
+
+A module level pass can use function level analysis info using this interface.
+For example:</p>
+
+<div class="doc_code"><pre>
+   bool ModuleLevelPass::runOnModule(Module &M) {
+     ...
+     DominatorTree &DT = getAnalysis<DominatorTree>(Function &F);
+     ...
+   }
+</pre></div>
+
+In above example, runOnFunction for DominatorTree is called by pass manager
+before returning a reference to the desired pass.</p>
 
 <p>
 If your pass is capable of updating analyses if they exist (e.g.,
@@ -1799,7 +1815,7 @@
 
   <a href="mailto:sabre at nondot.org">Chris Lattner</a><br>
   <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
-  Last modified: $Date: 2007/03/19 22:21:25 $
+  Last modified: $Date: 2007/04/16 21:28:14 $
 </address>
 
 </body>