From: Dan Gohman <gohman@apple.com>
Date: Tue, 9 Nov 2010 20:13:27 +0000 (+0000)
Subject: Use the AliasAnalysis interface to determine how a Function accesses
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=6d44d64f61359c865cbf2d7f331bb9c97ce253d5;p=oota-llvm.git

Use the AliasAnalysis interface to determine how a Function accesses
memory. This isn't a real improvement with present day AliasAnalysis
implementations; it's mainly for consistency.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118624 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/IPO/FunctionAttrs.cpp b/lib/Transforms/IPO/FunctionAttrs.cpp
index 71671d6fe9a..fcdc5f18f16 100644
--- a/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -101,14 +101,15 @@ bool FunctionAttrs::AddReadAttrs(const CallGraphSCC &SCC) {
       // External node - may write memory.  Just give up.
       return false;
 
-    if (F->doesNotAccessMemory())
+    AliasAnalysis::ModRefBehavior MRB = AA->getModRefBehavior(F);
+    if (MRB == AliasAnalysis::DoesNotAccessMemory)
       // Already perfect!
       continue;
 
     // Definitions with weak linkage may be overridden at linktime with
     // something that writes memory, so treat them like declarations.
     if (F->isDeclaration() || F->mayBeOverridden()) {
-      if (!F->onlyReadsMemory())
+      if (!AliasAnalysis::onlyReadsMemory(MRB))
         // May write memory.  Just give up.
         return false;