C Z6.0+fencembonceonce+poacquireonce+fencembonceacquire Hash=147985e896eaae9babb9ac83c80c2ee8 Cycle=FreAcquireOnce FenceMbdWWOnceOnce RfeOnceAcquire PodRWAcquireOnce WseOnceOnce FenceMbdWROnceAcquire Relax=FreAcquireOnce RfeOnceAcquire Safe=FenceMbdWW FenceMbdWR PodRWAcquireOnce WseOnceOnce Generator=diy7 (version 7.46+3) Prefetch=0:x=F,0:y=W,1:y=F,1:z=W,2:z=F,2:x=T Com=Rf Ws Fr Orig=FenceMbdWWOnceOnce RfeOnceAcquire PodRWAcquireOnce WseOnceOnce FenceMbdWROnceAcquire FreAcquireOnce {} P0(int* x,int* y) { WRITE_ONCE(*x,1); smp_mb(); WRITE_ONCE(*y,1); } P1(int* y,int* z) { int r0 = smp_load_acquire(y); WRITE_ONCE(*z,1); } P2(int* x,int* z) { WRITE_ONCE(*z,2); smp_mb(); int r0 = smp_load_acquire(x); } Observed z=2; 2:r0=0; 1:r0=1;
C11 equivalent:
C Z6.0+fencembonceonce+poacquireonce+fencembonceacquire Hash=147985e896eaae9babb9ac83c80c2ee8 Cycle=FreAcquireOnce FenceMbdWWOnceOnce RfeOnceAcquire PodRWAcquireOnce WseOnceOnce FenceMbdWROnceAcquire Relax=FreAcquireOnce RfeOnceAcquire Safe=FenceMbdWW FenceMbdWR PodRWAcquireOnce WseOnceOnce Generator=diy7 (version 7.46+3) Prefetch=0:x=F,0:y=W,1:y=F,1:z=W,2:z=F,2:x=T Com=Rf Ws Fr Orig=FenceMbdWWOnceOnce RfeOnceAcquire PodRWAcquireOnce WseOnceOnce FenceMbdWROnceAcquire FreAcquireOnce {} P0(atomic_int* x,atomic_int* y) { atomic_store_explicit(x,1,memory_order_relaxed); atomic_thread_fence(memory_order_seq_cst); atomic_store_explicit(y,1,memory_order_relaxed); } P1(atomic_int* y,atomic_int* z) { int r0 = atomic_load_explicit(y,memory_order_acquire); atomic_store_explicit(z,1,memory_order_relaxed); } P2(atomic_int* x,atomic_int* z) { atomic_store_explicit(z,2,memory_order_relaxed); atomic_thread_fence(memory_order_seq_cst); int r0 = atomic_load_explicit(x,memory_order_acquire); } exists (z=2 /\ 1:r0=1 /\ 2:r0=0)