libgomp/testsuite/libgomp.c/appendix-a/a.19.1.c

   1 /* { dg-do run } */
   2
   3 int x, *p = &x;
   4 extern void abort (void);
   5 void
   6 f1 (int *q)
   7 {
   8   *q = 1;
   9 #pragma omp flush
  10   /* x, p, and *q are flushed */
  11   /* because they are shared and accessible */
  12   /* q is not flushed because it is not shared. */
  13 }
  14
  15 void
  16 f2 (int *q)
  17 {
  18 #pragma omp barrier
  19   *q = 2;
  20 #pragma omp barrier
  21   /*  a barrier implies a flush */
  22   /*  x, p, and *q are flushed */
  23   /*  because they are shared and accessible */
  24   /*  q is not flushed because it is not shared. */
  25 }
  26
  27 int
  28 g (int n)
  29 {
  30   int i = 1, j, sum = 0;
  31   *p = 1;
  32 #pragma omp parallel reduction(+: sum) num_threads(2)
  33   {
  34     f1 (&j);
  35     /* i, n and sum were not flushed */
  36     /* because they were not accessible in f1 */
  37     /* j was flushed because it was accessible */
  38     sum += j;
  39     f2 (&j);
  40     /* i, n, and sum were not flushed */
  41     /* because they were not accessible in f2 */
  42     /* j was flushed because it was accessible */
  43     sum += i + j + *p + n;
  44   }
  45   return sum;
  46 }
  47
  48 int
  49 main ()
  50 {
  51   int result = g (10);
  52   if (result != 30)
  53     abort ();
  54   return 0;
  55 }