Make DAGCombiner's global alias analysis query more precise in the case
where both pointers have non-zero offsets.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41491 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index fda0589..0514bc1 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -4606,8 +4606,9 @@
if (CombinerGlobalAA) {
// Use alias analysis information.
- int Overlap1 = Size1 + SrcValueOffset1;
- int Overlap2 = Size2 + SrcValueOffset2;
+ int64_t MinOffset = std::min(SrcValueOffset1, SrcValueOffset2);
+ int64_t Overlap1 = Size1 + SrcValueOffset1 - MinOffset;
+ int64_t Overlap2 = Size2 + SrcValueOffset2 - MinOffset;
AliasAnalysis::AliasResult AAResult =
AA.alias(SrcValue1, Overlap1, SrcValue2, Overlap2);
if (AAResult == AliasAnalysis::NoAlias)