C Z6.3+fencemboncerelease+fencemboncerelease+poacquireacquire Hash=bffa3d21ba80ef9d35ca3d15989eef5a Cycle=PodRRAcquireAcquire FreAcquireOnce FenceMbdWWOnceRelease WseReleaseOnce FenceMbdWWOnceRelease RfeReleaseAcquire Relax=FreAcquireOnce RfeReleaseAcquire WseReleaseOnce Safe=FenceMbdWW PodRRAcquireAcquire 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=Ws Rf Fr Orig=FenceMbdWWOnceRelease WseReleaseOnce FenceMbdWWOnceRelease RfeReleaseAcquire PodRRAcquireAcquire FreAcquireOnce {} P0(int* x,int* y) { WRITE_ONCE(*x,1); smp_mb(); smp_store_release(y,1); } P1(int* y,int* z) { WRITE_ONCE(*y,2); smp_mb(); smp_store_release(z,1); } P2(int* x,int* z) { int r0 = smp_load_acquire(z); int r1 = smp_load_acquire(x); } Observed y=2; 2:r1=0; 2:r0=1;
C11 equivalent:
C Z6.3+fencemboncerelease+fencemboncerelease+poacquireacquire Hash=bffa3d21ba80ef9d35ca3d15989eef5a Cycle=PodRRAcquireAcquire FreAcquireOnce FenceMbdWWOnceRelease WseReleaseOnce FenceMbdWWOnceRelease RfeReleaseAcquire Relax=FreAcquireOnce RfeReleaseAcquire WseReleaseOnce Safe=FenceMbdWW PodRRAcquireAcquire 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=Ws Rf Fr Orig=FenceMbdWWOnceRelease WseReleaseOnce FenceMbdWWOnceRelease RfeReleaseAcquire PodRRAcquireAcquire 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_release); } P1(atomic_int* y,atomic_int* z) { atomic_store_explicit(y,2,memory_order_relaxed); atomic_thread_fence(memory_order_seq_cst); atomic_store_explicit(z,1,memory_order_release); } P2(atomic_int* x,atomic_int* z) { int r0 = atomic_load_explicit(z,memory_order_acquire); int r1 = atomic_load_explicit(x,memory_order_acquire); } exists (y=2 /\ 2:r0=1 /\ 2:r1=0)