C Z6.2+fencewmbonceonce+poacquirerelease+pooncerelease Hash=873997321422a62ac4f8ce75d3c5236e Cycle=PodRWAcquireRelease RfeReleaseOnce PodRWOnceRelease WseReleaseOnce FenceWmbdWWOnceOnce RfeOnceAcquire Relax=RfeOnceAcquire RfeReleaseOnce WseReleaseOnce Safe=FenceWmbdWW PodRWAcquireRelease PodRWOnceRelease 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=Rf Rf Ws Orig=FenceWmbdWWOnceOnce RfeOnceAcquire PodRWAcquireRelease RfeReleaseOnce PodRWOnceRelease WseReleaseOnce {} P0(int* x,int* y) { WRITE_ONCE(*x,2); smp_wmb(); WRITE_ONCE(*y,1); } P1(int* y,int* z) { int r0 = smp_load_acquire(y); smp_store_release(z,1); } P2(int* x,int* z) { int r0 = READ_ONCE(*z); smp_store_release(x,1); } Observed x=2; 2:r0=1; 1:r0=1;
C11 equivalent:
C Z6.2+fencewmbonceonce+poacquirerelease+pooncerelease Hash=873997321422a62ac4f8ce75d3c5236e Cycle=PodRWAcquireRelease RfeReleaseOnce PodRWOnceRelease WseReleaseOnce FenceWmbdWWOnceOnce RfeOnceAcquire Relax=RfeOnceAcquire RfeReleaseOnce WseReleaseOnce Safe=FenceWmbdWW PodRWAcquireRelease PodRWOnceRelease 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=Rf Rf Ws Orig=FenceWmbdWWOnceOnce RfeOnceAcquire PodRWAcquireRelease RfeReleaseOnce PodRWOnceRelease WseReleaseOnce {} P0(atomic_int* x,atomic_int* y) { atomic_store_explicit(x,2,memory_order_relaxed); atomic_thread_fence(memory_order_acq_rel); 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_release); } P2(atomic_int* x,atomic_int* z) { int r0 = atomic_load_explicit(z,memory_order_relaxed); atomic_store_explicit(x,1,memory_order_release); } exists (x=2 /\ 1:r0=1 /\ 2:r0=1)