1; RUN: llc < %s -march=x86-64 | FileCheck %s
2
3@var = external global i64 ; <i64*> [#uses=1]
4
5define i32 @main() nounwind {
6entry:
7; CHECK-LABEL: main:
8; CHECK: lock
9; CHECK: decq
10 atomicrmw sub i64* @var, i64 1 monotonic
11 unreachable
12}
13