1C SB+rfionceonce-poonceonces
 2
 3(*
 4 * Result: Sometimes
 5 *
 6 * This litmus test demonstrates that LKMM is not fully multicopy atomic.
 7 *)
 8
 9{}
10
11P0(int *x, int *y)
12{
13	int r1;
14	int r2;
15
16	WRITE_ONCE(*x, 1);
17	r1 = READ_ONCE(*x);
18	r2 = READ_ONCE(*y);
19}
20
21P1(int *x, int *y)
22{
23	int r3;
24	int r4;
25
26	WRITE_ONCE(*y, 1);
27	r3 = READ_ONCE(*y);
28	r4 = READ_ONCE(*x);
29}
30
31locations [0:r1; 1:r3; x; y] (* Debug aid: Print things not in "exists". *)
32exists (0:r2=0 /\ 1:r4=0)