C SB+poonceonces

(*
 * Result: Sometimes
 *
 * This litmus test demonstrates that at least some ordering is required
 * to order the store-buffering pattern, where each process writes to the
 * variable that the preceding process reads.
 *)

{
	int x;
	int y;
}

P0(int *x, int *y)
{
	int r0;

	WRITE_ONCE(*x, 1);
	r0 = READ_ONCE(*y);
}

P1(int *x, int *y)
{
	int r0;

	WRITE_ONCE(*y, 1);
	r0 = READ_ONCE(*x);
}

exists (0:r0=0 /\ 1:r0=0)