1  #include <omp.h>
       2  #include <stdlib.h>
       3  
       4  int
       5  main (void)
       6  {
       7    int i = 0, j = 0, k = ~0, l;
       8    double d = 1.0;
       9  #pragma omp parallel num_threads(4)
      10    {
      11  #pragma omp single
      12      {
      13        i = 16;
      14        k ^= (1 << 16);
      15        d += 32.0;
      16      }
      17  
      18  #pragma omp for reduction(+:i) reduction(*:d) reduction(&:k) nowait
      19      for (l = 0; l < 4; l++)
      20        {
      21  	if (omp_get_num_threads () == 4 && (i != 0 || d != 1.0 || k != ~0))
      22  #pragma omp atomic
      23  	  j |= 1;
      24    
      25  	if (l == omp_get_thread_num ())
      26  	  {
      27  	    i = omp_get_thread_num ();
      28  	    d = i + 1;
      29  	    k = ~(1 << (2 * i));
      30  	  }
      31        }
      32  
      33      if (omp_get_num_threads () == 4)
      34        {
      35  #pragma omp barrier
      36  	if (i != (16 + 0 + 1 + 2 + 3))
      37  #pragma omp atomic
      38  	  j |= 2;
      39  	if (d != (33.0 * 1.0 * 2.0 * 3.0 * 4.0))
      40  #pragma omp atomic
      41  	  j |= 4;
      42  	if (k != (~0 ^ 0x55 ^ (1 << 16)))
      43  #pragma omp atomic
      44  	  j |= 8;
      45        }
      46    }
      47  
      48    if (j)
      49      abort ();
      50    return 0;
      51  }