gcc/testsuite/gcc.dg/atomic/stdatomic-exchange-1.c

/* Test atomic_exchange routines for existence and proper execution on
   1-byte values with each valid memory model.  */
/* { dg-do run } */
/* { dg-options "-std=c11 -pedantic-errors" } */

#include <stdatomic.h>

extern void abort (void);

_Atomic char v;
char count, ret;

int
main ()
{
  v = 0;
  count = 0;

  if (atomic_exchange_explicit (&v, count + 1, memory_order_relaxed) != count)
    abort ();
  count++;

  if (atomic_exchange_explicit (&v, count + 1, memory_order_acquire) != count)
    abort ();
  count++;

  if (atomic_exchange_explicit (&v, count + 1, memory_order_release) != count)
    abort ();
  count++;

  if (atomic_exchange_explicit (&v, count + 1, memory_order_acq_rel) != count)
    abort ();
  count++;

  if (atomic_exchange_explicit (&v, count + 1, memory_order_seq_cst) != count)
    abort ();
  count++;

  count++;

  ret = atomic_exchange (&v, count);
  if (ret != count - 1 || v != count)
    abort ();

  return 0;
}