From: Chris Lattner <sabre@nondot.org>
Date: Wed, 23 Mar 2005 23:27:34 +0000 (+0000)
Subject: if a function doesn't access memory at all, it definitely doesn't read it.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=8eec644862251e14add0d2707d655fcce91e8f70;p=oota-llvm.git

if a function doesn't access memory at all, it definitely doesn't read it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20794 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/Analysis/AliasAnalysis.h b/include/llvm/Analysis/AliasAnalysis.h
index 73b646d9356..0857190c5c7 100644
--- a/include/llvm/Analysis/AliasAnalysis.h
+++ b/include/llvm/Analysis/AliasAnalysis.h
@@ -214,7 +214,8 @@ public:
   bool onlyReadsMemory(Function *F) {
     /// FIXME: If the analysis returns more precise info, we can reduce it to
     /// this.
-    return getModRefBehavior(F, CallSite()) == OnlyReadsMemory;
+    ModRefBehavior MRB = getModRefBehavior(F, CallSite());
+    return MRB == DoesNotAccessMemory || MRB == OnlyReadsMemory;
   }