libgomp/testsuite/libgomp.c/appendix-a/a.16.1.c

   1 /* { dg-do run } */
   2
   3 #include <stdio.h>
   4
   5 float
   6 work1 (int i)
   7 {
   8   return 1.0 * i;
   9 }
  10
  11 float
  12 work2 (int i)
  13 {
  14   return 2.0 * i;
  15 }
  16
  17 void
  18 a16 (float *x, float *y, int *index, int n)
  19 {
  20   int i;
  21 #pragma omp parallel for shared(x, y, index, n)
  22   for (i = 0; i < n; i++)
  23     {
  24 #pragma omp atomic
  25       x[index[i]] += work1 (i);
  26       y[i] += work2 (i);
  27     }
  28 }
  29 int
  30 main ()
  31 {
  32   float x[1000];
  33   float y[10000];
  34   int index[10000];
  35   int i;
  36   for (i = 0; i < 10000; i++)
  37     {
  38       index[i] = i % 1000;
  39       y[i] = 0.0;
  40     }
  41   for (i = 0; i < 1000; i++)
  42     x[i] = 0.0;
  43   a16 (x, y, index, 10000);
  44   for (i = 0; i < 10; i++)
  45     printf ("x[%d] = %f, y[%d] = %f\n", i, x[i], i, y[i]);
  46   return 0;
  47 }