C Z6.1+fencembreleaseonce+fencewmbonceonce+fencemboncerelease Hash=cc7c1e1603ed370435cf44434d4a0d9d Cycle=RfeOnceOnce FenceMbdRWOnceRelease WseReleaseRelease FenceMbdWWReleaseOnce WseOnceOnce FenceWmbdWWOnceOnce Relax=WseReleaseRelease Safe=FenceMbdWW FenceMbdRW FenceWmbdWW RfeOnceOnce 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=W Com=Ws Rf Ws Orig=FenceMbdWWReleaseOnce WseOnceOnce FenceWmbdWWOnceOnce RfeOnceOnce FenceMbdRWOnceRelease WseReleaseRelease {} P0(int* x,int* y) { smp_store_release(x,2); smp_mb(); WRITE_ONCE(*y,1); } P1(int* y,int* z) { WRITE_ONCE(*y,2); smp_wmb(); WRITE_ONCE(*z,1); } P2(int* x,int* z) { int r0 = READ_ONCE(*z); smp_mb(); smp_store_release(x,1); } Observed y=2; x=2; 2:r0=1;
C11 equivalent:
C Z6.1+fencembreleaseonce+fencewmbonceonce+fencemboncerelease Hash=cc7c1e1603ed370435cf44434d4a0d9d Cycle=RfeOnceOnce FenceMbdRWOnceRelease WseReleaseRelease FenceMbdWWReleaseOnce WseOnceOnce FenceWmbdWWOnceOnce Relax=WseReleaseRelease Safe=FenceMbdWW FenceMbdRW FenceWmbdWW RfeOnceOnce 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=W Com=Ws Rf Ws Orig=FenceMbdWWReleaseOnce WseOnceOnce FenceWmbdWWOnceOnce RfeOnceOnce FenceMbdRWOnceRelease WseReleaseRelease {} P0(atomic_int* x,atomic_int* y) { atomic_store_explicit(x,2,memory_order_release); atomic_thread_fence(memory_order_seq_cst); atomic_store_explicit(y,1,memory_order_relaxed); } P1(atomic_int* y,atomic_int* z) { atomic_store_explicit(y,2,memory_order_relaxed); atomic_thread_fence(memory_order_acq_rel); atomic_store_explicit(z,1,memory_order_relaxed); } P2(atomic_int* x,atomic_int* z) { int r0 = atomic_load_explicit(z,memory_order_relaxed); atomic_thread_fence(memory_order_seq_cst); atomic_store_explicit(x,1,memory_order_release); } exists (x=2 /\ y=2 /\ 2:r0=1)