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