[llvm-commits] [llvm] r118416 - /llvm/trunk/lib/Analysis/TypeBasedAliasAnalysis.cpp

[Dan Gohman]

Author: djg
Date: Mon Nov  8 11:10:22 2010
New Revision: 118416

URL: http://llvm.org/viewvc/llvm-project?rev=118416&view=rev
Log:
Implement getModRefBehavior for TypeBasedAliasAnalysis.

Modified:
    llvm/trunk/lib/Analysis/TypeBasedAliasAnalysis.cpp

Modified: llvm/trunk/lib/Analysis/TypeBasedAliasAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/TypeBasedAliasAnalysis.cpp?rev=118416&r1=118415&r2=118416&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/TypeBasedAliasAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/TypeBasedAliasAnalysis.cpp Mon Nov  8 11:10:22 2010
@@ -139,6 +139,8 @@
     virtual void getAnalysisUsage(AnalysisUsage &AU) const;
     virtual AliasResult alias(const Location &LocA, const Location &LocB);
     virtual bool pointsToConstantMemory(const Location &Loc, bool OrLocal);
+    virtual ModRefBehavior getModRefBehavior(ImmutableCallSite CS);
+    virtual ModRefBehavior getModRefBehavior(const Function *F);
     virtual ModRefResult getModRefInfo(ImmutableCallSite CS,
                                        const Location &Loc);
     virtual ModRefResult getModRefInfo(ImmutableCallSite CS1,
@@ -241,6 +243,27 @@
   return AliasAnalysis::pointsToConstantMemory(Loc, OrLocal);
 }
 
+AliasAnalysis::ModRefBehavior
+TypeBasedAliasAnalysis::getModRefBehavior(ImmutableCallSite CS) {
+  if (!EnableTBAA)
+    return AliasAnalysis::getModRefBehavior(CS);
+
+  ModRefBehavior Min = UnknownModRefBehavior;
+
+  // If this is an "immutable" type, we can assume the call doesn't write
+  // to memory.
+  if (const MDNode *M = CS.getInstruction()->getMetadata(LLVMContext::MD_tbaa))
+    if (TBAANode(M).TypeIsImmutable())
+      Min = OnlyReadsMemory;
+
+  return std::min(AliasAnalysis::getModRefBehavior(CS), Min);
+}
+
+AliasAnalysis::ModRefBehavior
+TypeBasedAliasAnalysis::getModRefBehavior(const Function *F) {
+  return AliasAnalysis::getModRefBehavior(F);
+}
+
 AliasAnalysis::ModRefResult
 TypeBasedAliasAnalysis::getModRefInfo(ImmutableCallSite CS,
                                       const Location &Loc) {