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 %pair = cmpxchg i64* %ptr, i64 0, i64 1 monotonic monotonic 22 %r = extractvalue { i64, i1 } %pair, 0 23 %stored1 = icmp eq i64 %r, 0 24 br i1 %stored1, label %loop, label %continue 25continue: 26 ret void 27} 28