libgomp/testsuite/libgomp.c/examples-4/teams-2.c

   1 /* { dg-do run } */
   2
   3 #include <stdlib.h>
   4
   5 #define EPS 0.0001
   6 #define N 1024*1024
   7
   8 void init (float B[], float C[], int n)
   9 {
  10   int i;
  11   for (i = 0; i < n; i++)
  12     {
  13       B[i] = 0.1 * i;
  14       C[i] = 0.01 * i * i;
  15     }
  16 }
  17
  18 float dotprod_ref (float B[], float C[], int n)
  19 {
  20   int i;
  21   float sum = 0.0;
  22
  23   for (i = 0; i < n; i++)
  24     sum += B[i] * C[i];
  25
  26   return sum;
  27 }
  28
  29 float dotprod (float B[], float C[], int n, int block_size,
  30                int num_teams, int block_threads)
  31 {
  32   int i, i0;
  33   float sum = 0;
  34
  35   #pragma omp target map(to: B[0:n], C[0:n]) map(tofrom: sum)
  36     #pragma omp teams num_teams(num_teams) thread_limit(block_threads) \
  37                       reduction(+:sum)
  38       #pragma omp distribute
  39         for (i0 = 0; i0 < n; i0 += block_size)
  40           #pragma omp parallel for reduction(+:sum)
  41             for (i = i0; i < ((i0 + block_size > n) ? n : i0 + block_size); i++)
  42               sum += B[i] * C[i];
  43
  44   return sum;
  45 }
  46
  47 void check (float a, float b)
  48 {
  49   float err = (b == 0.0) ? a : (a - b) / b;
  50   if (((err > 0) ? err : -err) > EPS)
  51     abort ();
  52 }
  53
  54 int main ()
  55 {
  56   float *v1 = (float *) malloc (N * sizeof (float));
  57   float *v2 = (float *) malloc (N * sizeof (float));
  58
  59   float p1, p2;
  60
  61   init (v1, v2, N);
  62
  63   p1 = dotprod_ref (v1, v2, N);
  64   p2 = dotprod (v1, v2, N, N / 8, 2, 8);
  65
  66   check (p1, p2);
  67
  68   free (v1);
  69   free (v2);
  70
  71   return 0;
  72 }