SelectionDAG: skip barriers for unordered atomic operations
Unordered is strictly weaker than monotonic, so if the latter doesn't have any
barriers then the former certainly shouldn't.
rdar://problem/16548260
llvm-svn: 209901
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 070e929..8d10a80 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -3570,12 +3570,12 @@
if (Before) {
if (Order == AcquireRelease || Order == SequentiallyConsistent)
Order = Release;
- else if (Order == Acquire || Order == Monotonic)
+ else if (Order == Acquire || Order == Monotonic || Order == Unordered)
return Chain;
} else {
if (Order == AcquireRelease)
Order = Acquire;
- else if (Order == Release || Order == Monotonic)
+ else if (Order == Release || Order == Monotonic || Order == Unordered)
return Chain;
}
SDValue Ops[3];