UI != UE; ++UI) { // Loop over all of the uses of the alloca
const User *U = *UI;
if (const LoadInst *LI = dyn_cast<LoadInst>(U)) {
+ // Note that atomic loads can be transformed; atomic semantics do
+ // not have any meaning for a local alloca.
if (LI->isVolatile())
return false;
} else if (const StoreInst *SI = dyn_cast<StoreInst>(U)) {
if (SI->getOperand(0) == AI)
return false; // Don't allow a store OF the AI, only INTO the AI.
+ // Note that atomic stores can be transformed; atomic semantics do
+ // not have any meaning for a local alloca.
if (SI->isVolatile())
return false;
} else if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(U)) {
--- /dev/null
+; RUN: opt -mem2reg < %s -S | FileCheck %s
+
+; mem2reg is allowed with arbitrary atomic operations (although we only support
+; it for atomic load and store at the moment).
+define i32 @test1(i32 %x) {
+; CHECK: @test1
+; CHECK: ret i32 %x
+ %a = alloca i32
+ store atomic i32 %x, i32* %a seq_cst, align 4
+ %r = load atomic i32* %a seq_cst, align 4
+ ret i32 %r
+}