C ISA2+fencemboncerelease+poacquireonce+poacquireacquire Hash=055e2b491e5bb7a81e14fd71378009fa Cycle=PodRRAcquireAcquire FreAcquireOnce FenceMbdWWOnceRelease RfeReleaseAcquire PodRWAcquireOnce RfeOnceAcquire Relax=FreAcquireOnce RfeOnceAcquire RfeReleaseAcquire Safe=FenceMbdWW PodRRAcquireAcquire PodRWAcquireOnce 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 Rf Fr Orig=FenceMbdWWOnceRelease RfeReleaseAcquire PodRWAcquireOnce RfeOnceAcquire PodRRAcquireAcquire FreAcquireOnce {} P0(int* x,int* y) { WRITE_ONCE(*x,1); smp_mb(); smp_store_release(y,1); } P1(int* y,int* z) { int r0 = smp_load_acquire(y); WRITE_ONCE(*z,1); } P2(int* x,int* z) { int r0 = smp_load_acquire(z); int r1 = smp_load_acquire(x); } Observed 2:r1=0; 2:r0=1; 1:r0=1;
C11 equivalent:
C ISA2+fencemboncerelease+poacquireonce+poacquireacquire Hash=055e2b491e5bb7a81e14fd71378009fa Cycle=PodRRAcquireAcquire FreAcquireOnce FenceMbdWWOnceRelease RfeReleaseAcquire PodRWAcquireOnce RfeOnceAcquire Relax=FreAcquireOnce RfeOnceAcquire RfeReleaseAcquire Safe=FenceMbdWW PodRRAcquireAcquire PodRWAcquireOnce 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 Rf Fr Orig=FenceMbdWWOnceRelease RfeReleaseAcquire PodRWAcquireOnce RfeOnceAcquire 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) { int r0 = atomic_load_explicit(y,memory_order_acquire); atomic_store_explicit(z,1,memory_order_relaxed); } 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 (1:r0=1 /\ 2:r0=1 /\ 2:r1=0)