Implement handling of constantexprs for disambiguation. This implements

BasicAA/featuretest.ll:constexpr_test

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@6740 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 42d00c2b605d8771cba00bc568d3029936c3b848..b56782b5066c8694caeaecab2b844c38189b3117 100644 (file)
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -69,6 +69,12 @@ static const Value *getUnderlyingObject(const Value *V) {
   if (const Instruction *I = dyn_cast<Instruction>(V)) {
     if (isa<CastInst>(I) || isa<GetElementPtrInst>(I))
       return getUnderlyingObject(I->getOperand(0));
+  } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
+    if (CE->getOpcode() == Instruction::Cast ||
+        CE->getOpcode() == Instruction::GetElementPtr)
+      return getUnderlyingObject(CE->getOperand(0));
+  } else if (const ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(V)) {
+    return CPR->getValue();
   }
   return 0;
 }