162306a36Sopenharmony_ciC SB+rfionceonce-poonceonces 262306a36Sopenharmony_ci 362306a36Sopenharmony_ci(* 462306a36Sopenharmony_ci * Result: Sometimes 562306a36Sopenharmony_ci * 662306a36Sopenharmony_ci * This litmus test demonstrates that LKMM is not fully multicopy atomic. 762306a36Sopenharmony_ci *) 862306a36Sopenharmony_ci 962306a36Sopenharmony_ci{} 1062306a36Sopenharmony_ci 1162306a36Sopenharmony_ciP0(int *x, int *y) 1262306a36Sopenharmony_ci{ 1362306a36Sopenharmony_ci int r1; 1462306a36Sopenharmony_ci int r2; 1562306a36Sopenharmony_ci 1662306a36Sopenharmony_ci WRITE_ONCE(*x, 1); 1762306a36Sopenharmony_ci r1 = READ_ONCE(*x); 1862306a36Sopenharmony_ci r2 = READ_ONCE(*y); 1962306a36Sopenharmony_ci} 2062306a36Sopenharmony_ci 2162306a36Sopenharmony_ciP1(int *x, int *y) 2262306a36Sopenharmony_ci{ 2362306a36Sopenharmony_ci int r3; 2462306a36Sopenharmony_ci int r4; 2562306a36Sopenharmony_ci 2662306a36Sopenharmony_ci WRITE_ONCE(*y, 1); 2762306a36Sopenharmony_ci r3 = READ_ONCE(*y); 2862306a36Sopenharmony_ci r4 = READ_ONCE(*x); 2962306a36Sopenharmony_ci} 3062306a36Sopenharmony_ci 3162306a36Sopenharmony_cilocations [0:r1; 1:r3; x; y] (* Debug aid: Print things not in "exists". *) 3262306a36Sopenharmony_ciexists (0:r2=0 /\ 1:r4=0) 33