make sure not to zap volatile stores, thanks a lot to Dale for noticing this!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45402 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 0ee45575633197937e2f047bd60773d99795b294..cfa46e6b59136714ea0dfc8763ce6f82c6ef6ea4 100644 (file)
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -4252,7 +4252,8 @@ SDOperand DAGCombiner::visitSTORE(SDNode *N) {
   if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Value)) {
     if (Chain.Val == Ld && Ld->getBasePtr() == Ptr &&
         ST->getAddressingMode() == ISD::UNINDEXED &&
-        ST->getStoredVT() == Ld->getLoadedVT()) {
+        ST->getStoredVT() == Ld->getLoadedVT() &&
+        !ST->isVolatile()) {
       // The store is dead, remove it.
       return Chain;
     }