1; RUN: llc < %s -march=x86 -mtriple=i386-apple-darwin | FileCheck %s
2; PR8297
3;
4; On i386, i64 cmpxchg is lowered during legalize types to extract the
5; 64-bit result into a pair of fixed regs. So creation of the DAG node
6; happens in a different place. See
7; X86TargetLowering::ReplaceNodeResults, case ATOMIC_CMP_SWAP.
8;
9; Neither Atomic-xx.ll nor atomic_op.ll cover this. Those tests were
10; autogenerated from C source before 64-bit variants were supported.
11;
12; Note that this case requires a loop around the cmpxchg to force
13; machine licm to query alias anlysis, exposing a bad
14; MachineMemOperand.
15define void @foo(i64* %ptr) nounwind inlinehint {
16entry:
17  br label %loop
18loop:
19; CHECK: lock
20; CHECK-NEXT: cmpxchg8b
21  %r = cmpxchg i64* %ptr, i64 0, i64 1 monotonic
22  %stored1  = icmp eq i64 %r, 0
23  br i1 %stored1, label %loop, label %continue
24continue:
25  ret void
26}
27