Do not optimize atomic load to non-atomic memcmp
Differential Revision: https://reviews.llvm.org/D51998
llvm-svn: 342498
diff --git a/llvm/lib/Transforms/Scalar/MergeICmps.cpp b/llvm/lib/Transforms/Scalar/MergeICmps.cpp
index ff0183a..7b3c3f9 100644
--- a/llvm/lib/Transforms/Scalar/MergeICmps.cpp
+++ b/llvm/lib/Transforms/Scalar/MergeICmps.cpp
@@ -81,8 +81,9 @@
LLVM_DEBUG(dbgs() << "used outside of block\n");
return {};
}
- if (LoadI->isVolatile()) {
- LLVM_DEBUG(dbgs() << "volatile\n");
+ // Do not optimize atomic loads to non-atomic memcmp
+ if (!LoadI->isSimple()) {
+ LLVM_DEBUG(dbgs() << "volatile or atomic\n");
return {};
}
Value *const Addr = LoadI->getOperand(0);