Make DecomposeGEPExpression check SimplifyInstruction only
after checking for a GEP, so that it matches what GetUnderlyingObject
does. This fixes an obscure bug turned up by bugpoint in the testcase
for PR9931.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131971 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 989d8e0..03785fd 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -281,17 +281,20 @@
continue;
}
- if (const Instruction *I = dyn_cast<Instruction>(V))
- // TODO: Get a DominatorTree and use it here.
- if (const Value *Simplified =
- SimplifyInstruction(const_cast<Instruction *>(I), TD)) {
- V = Simplified;
- continue;
- }
-
const GEPOperator *GEPOp = dyn_cast<GEPOperator>(Op);
- if (GEPOp == 0)
+ if (GEPOp == 0) {
+ // If it's not a GEP, hand it off to SimplifyInstruction to see if it
+ // can come up with something. This matches what GetUnderlyingObject does.
+ if (const Instruction *I = dyn_cast<Instruction>(V))
+ // TODO: Get a DominatorTree and use it here.
+ if (const Value *Simplified =
+ SimplifyInstruction(const_cast<Instruction *>(I), TD)) {
+ V = Simplified;
+ continue;
+ }
+
return V;
+ }
// Don't attempt to analyze GEPs over unsized objects.
if (!cast<PointerType>(GEPOp->getOperand(0)->getType())