[instcombine][unordered] Extend load(select) transform to handle unordered loads
llvm-svn: 267023
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
index 981dfc1..4ca9ab4 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
@@ -867,10 +867,6 @@
return replaceInstUsesWith(LI, UndefValue::get(LI.getType()));
}
- // TODO: The transform below needs updated for unordered loads
- if (!LI.isSimple())
- return nullptr;
-
if (Op->hasOneUse()) {
// Change select and PHI nodes to select values instead of addresses: this
// helps alias analysis out a lot, allows many others simplifications, and
@@ -891,8 +887,11 @@
SI->getOperand(1)->getName()+".val");
LoadInst *V2 = Builder->CreateLoad(SI->getOperand(2),
SI->getOperand(2)->getName()+".val");
+ assert(LI.isUnordered() && "implied by above");
V1->setAlignment(Align);
+ V1->setAtomic(LI.getOrdering(), LI.getSynchScope());
V2->setAlignment(Align);
+ V2->setAtomic(LI.getOrdering(), LI.getSynchScope());
return SelectInst::Create(SI->getCondition(), V1, V2);
}