Don't zap back to back volatile load/stores
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41759 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 26df555..f9abafa 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -9066,7 +9066,7 @@
// the pointer we're loading and is producing the pointer we're storing,
// then *this* store is dead (X = load P; store X -> P).
if (LoadInst *LI = dyn_cast<LoadInst>(BBI)) {
- if (LI == Val && LI->getOperand(0) == Ptr) {
+ if (LI == Val && LI->getOperand(0) == Ptr && !SI.isVolatile()) {
EraseInstFromFunction(SI);
++NumCombined;
return 0;