Make this more efficient by only making one virtual method call.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20793 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 4 deletions

diff --git a/lib/Analysis/AliasAnalysis.cpp b/lib/Analysis/AliasAnalysis.cpp
index da54c1b3da..5236435d20 100644
--- a/lib/Analysis/AliasAnalysis.cpp
+++ b/lib/Analysis/AliasAnalysis.cpp
@@ -114,11 +114,13 @@ AliasAnalysis::getModRefInfo(StoreInst *S, Value *P, unsigned Size) {
 AliasAnalysis::ModRefResult
 AliasAnalysis::getModRefInfo(CallSite CS, Value *P, unsigned Size) {
   ModRefResult Mask = ModRef;
-  if (Function *F = CS.getCalledFunction())
-    if (onlyReadsMemory(F)) {
-      if (doesNotAccessMemory(F)) return NoModRef;
+  if (Function *F = CS.getCalledFunction()) {
+    ModRefBehavior MRB = getModRefBehavior(F, CallSite());
+    if (MRB == OnlyReadsMemory)
       Mask = Ref;
-    }
+    else if (MRB == DoesNotAccessMemory)
+      return NoModRef;
+  }
 
   if (!AA) return Mask;