[PATCH] [AtomicExpand] Fix a crash bug when lowering unordered loads to cmpxchg

Add tests for wider atomic loads and stores.  In the process, fix a crasher where we appearently handled unorder stores, but not loads, when lowering to cmpxchg idioms.

llvm-svn: 356482

Gbp-Pq: Name AtomicExpand-Fix-a-crash-bug-when-lowering-unordered-loads.patch

diff --git a/lib/CodeGen/AtomicExpandPass.cpp b/lib/CodeGen/AtomicExpandPass.cpp
index e28fc6fb9d4fb60dc47675b1989a9354e2b52914..b58490f1ef5955ed87eec60353cb122ab2264540 100644 (file)
--- a/lib/CodeGen/AtomicExpandPass.cpp
+++ b/lib/CodeGen/AtomicExpandPass.cpp
@@ -423,6 +423,9 @@ bool AtomicExpand::expandAtomicLoadToLL(LoadInst *LI) {
 bool AtomicExpand::expandAtomicLoadToCmpXchg(LoadInst *LI) {
   IRBuilder<> Builder(LI);
   AtomicOrdering Order = LI->getOrdering();
+  if (Order == AtomicOrdering::Unordered)
+    Order = AtomicOrdering::Monotonic;
+
   Value *Addr = LI->getPointerOperand();
   Type *Ty = cast<PointerType>(Addr->getType())->getElementType();
   Constant *DummyVal = Constant::getNullValue(Ty);