162306a36Sopenharmony_ciC CoRW+poonceonce+Once 262306a36Sopenharmony_ci 362306a36Sopenharmony_ci(* 462306a36Sopenharmony_ci * Result: Never 562306a36Sopenharmony_ci * 662306a36Sopenharmony_ci * Test of read-write coherence, that is, whether or not a read from 762306a36Sopenharmony_ci * a given variable and a later write to that same variable are ordered. 862306a36Sopenharmony_ci *) 962306a36Sopenharmony_ci 1062306a36Sopenharmony_ci{} 1162306a36Sopenharmony_ci 1262306a36Sopenharmony_ciP0(int *x) 1362306a36Sopenharmony_ci{ 1462306a36Sopenharmony_ci int r0; 1562306a36Sopenharmony_ci 1662306a36Sopenharmony_ci r0 = READ_ONCE(*x); 1762306a36Sopenharmony_ci WRITE_ONCE(*x, 1); 1862306a36Sopenharmony_ci} 1962306a36Sopenharmony_ci 2062306a36Sopenharmony_ciP1(int *x) 2162306a36Sopenharmony_ci{ 2262306a36Sopenharmony_ci WRITE_ONCE(*x, 2); 2362306a36Sopenharmony_ci} 2462306a36Sopenharmony_ci 2562306a36Sopenharmony_ciexists (x=2 /\ 0:r0=2) 26