[SLSR] S's basis must have the same type as S

llvm-svn: 240910

1 files changed, 4 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp
index f32769c2411..6d9d417ef94 100644
--- a/llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp
@@ -224,11 +224,13 @@ FunctionPass *llvm::createStraightLineStrengthReducePass() {
 bool StraightLineStrengthReduce::isBasisFor(const Candidate &Basis,
                                             const Candidate &C) {
   return (Basis.Ins != C.Ins && // skip the same instruction
+          // They must have the same type too. Basis.Base == C.Base doesn't
+          // guarantee their types are the same (PR23975).
+          Basis.Ins->getType() == C.Ins->getType() &&
           // Basis must dominate C in order to rewrite C with respect to Basis.
           DT->dominates(Basis.Ins->getParent(), C.Ins->getParent()) &&
           // They share the same base, stride, and candidate kind.
-          Basis.Base == C.Base &&
-          Basis.Stride == C.Stride &&
+          Basis.Base == C.Base && Basis.Stride == C.Stride &&
           Basis.CandidateKind == C.CandidateKind);
 }