1  /* Test atomic_compare_exchange routines for existence and proper
       2     execution on 1-byte values with each valid memory model.  */
       3  /* { dg-do run } */
       4  /* { dg-options "-std=c11 -pedantic-errors" } */
       5  
       6  #include <stdatomic.h>
       7  
       8  extern void abort (void);
       9  
      10  _Atomic char v = ATOMIC_VAR_INIT (0);
      11  char expected = 0;
      12  char max = ~0;
      13  char desired = ~0;
      14  char zero = 0;
      15  
      16  int
      17  main ()
      18  {
      19  
      20    if (!atomic_compare_exchange_strong_explicit (&v, &expected, max, memory_order_relaxed, memory_order_relaxed))
      21      abort ();
      22    if (expected != 0)
      23      abort ();
      24  
      25    if (atomic_compare_exchange_strong_explicit (&v, &expected, 0, memory_order_acquire, memory_order_relaxed))
      26      abort ();
      27    if (expected != max)
      28      abort ();
      29  
      30    if (!atomic_compare_exchange_strong_explicit (&v, &expected, 0, memory_order_release, memory_order_acquire))
      31      abort ();
      32    if (expected != max)
      33      abort ();
      34    if (v != 0)
      35      abort ();
      36  
      37    if (atomic_compare_exchange_weak_explicit (&v, &expected, desired, memory_order_acq_rel, memory_order_acquire))
      38      abort ();
      39    if (expected != 0)
      40      abort ();
      41  
      42    if (!atomic_compare_exchange_strong_explicit (&v, &expected, desired, memory_order_seq_cst, memory_order_seq_cst))
      43      abort ();
      44    if (expected != 0)
      45      abort ();
      46    if (v != max)
      47      abort ();
      48  
      49    v = 0;
      50  
      51    if (!atomic_compare_exchange_strong (&v, &expected, max))
      52      abort ();
      53    if (expected != 0)
      54      abort ();
      55  
      56    if (atomic_compare_exchange_strong (&v, &expected, zero))
      57      abort ();
      58    if (expected != max)
      59      abort ();
      60  
      61    if (!atomic_compare_exchange_strong (&v, &expected, zero))
      62      abort ();
      63    if (expected != max)
      64      abort ();
      65    if (v != 0)
      66      abort ();
      67  
      68    if (atomic_compare_exchange_weak (&v, &expected, desired))
      69      abort ();
      70    if (expected != 0)
      71      abort ();
      72  
      73    if (!atomic_compare_exchange_strong (&v, &expected, desired))
      74      abort ();
      75    if (expected != 0)
      76      abort ();
      77    if (v != max)
      78      abort ();
      79  
      80    return 0;
      81  }