The two-callsite form of AliasAnalysis::getModRefInfo is documented
to return Ref if the left callsite only reads memory read or written
by the right callsite; fix BasicAliasAnalysis to implement this.

Add AliasAnalysisEvaluator support for testing the two-callsite
form of getModRefInfo.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110270 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 6bb84d4..ac06e9a 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -425,8 +425,8 @@
   ModRefBehavior CS2B = AliasAnalysis::getModRefBehavior(CS2);
   if (CS2B == DoesNotAccessMemory) return NoModRef;
   
-  // If they both only read from memory, just return ref.
-  if (CS1B == OnlyReadsMemory && CS2B == OnlyReadsMemory)
+  // If CS1 only reads from memory, just return ref.
+  if (CS1B == OnlyReadsMemory)
     return Ref;
   
   // Otherwise, fall back to NoAA (mod+ref).