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/* { dg-do run } */
/* { dg-options "-pthread" } */
/* { dg-require-effective-target pthread } */
#include <pthread.h>
static volatile int sem1;
static _Atomic int sem2;
static void *f(void *va)
{
void **p = va;
if (*p) return *p;
sem1 = 1;
while (!__atomic_load_n(&sem2, __ATOMIC_ACQUIRE))
sched_yield ();
// GCC used to RTL-CSE this and the first load, causing 0 to be returned
return *p;
}
int main()
{
void *p = 0;
pthread_t thr;
if (pthread_create(&thr, 0, f, &p))
return 2;
while (!sem1)
sched_yield ();
__atomic_thread_fence(__ATOMIC_ACQUIRE);
p = &p;
__atomic_store_n(&sem2, 1, __ATOMIC_RELEASE);
pthread_join(thr, &p);
return !p;
}
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