source: CIVL/examples/omp/fig3.10-mxv-omp.cvl@ 397ae5f

/* fig3.10-mxv-omp.cvl: CIVL model of fig3.10-mxv-omp.c
 * Translated by Stephen Siegel.
 */
#include <civlc.h>
#include <stdio.h>
#include <stdlib.h>
#define THREAD_MAX 4
/* Does thread t own iteration i in loop with n iterations? */
#define CIVL_owns(t, n, i) ((i)%(n)==(t))

void mxv(int m, int n, double * restrict a,
         double * restrict b, double * restrict c);

void perror(char *s) {
  printf("%s\n", s);
  exit(1);
}

int main(int argc, char *argv[])
{
   double *a,*b,*c;
   int i, j, m, n;

   printf("Please give m and n: ");
   scanf("%d %d",&m,&n);
   printf("\n");

   if ( (a=(double *)malloc(m*sizeof(double))) == NULL )
     perror("memory allocation for a");
   if ( (b=(double *)malloc(m*n*sizeof(double))) == NULL )
     perror("memory allocation for b");
   if ( (c=(double *)malloc(n*sizeof(double))) == NULL )
     perror("memory allocation for c");

   printf("Initializing matrix B and vector c\n");
   for (j=0; j<n; j++)
     c[j] = 2.0;
   for (i=0; i<m; i++)
     for (j=0; j<n; j++)
       b[i*n+j] = i;
   
   printf("Executing mxv function for m = %d n = %d\n",m,n);
   (void) mxv(m, n, a, b, c);
   
   free(a);free(b);free(c);
   return(0);
}

void mxv(int m, int n, double * restrict a, double * restrict b,
         double * restrict c)
{

   // #pragma omp parallel for default(none)
   //   shared(m,n,a,b,c) private(i,j)
  {
    int _nthreads = 1+$choose_int(THREAD_MAX);
    $proc _threads[_nthreads];
    void loop(int _tid) {
      int i, j;
      
      for (i=0; i<m; i++) {
        if (CIVL_owns(_tid, _nthreads, i)) {
          a[i] = 0.0;
          for (j=0; j<n; j++)
            a[i] += b[i*n+j]*c[j];
        }
      }
    }

    printf("nthreads = %d\n", _nthreads); // for debugging
    for (int tid=0; tid<_nthreads; tid++)
      _threads[tid] = $spawn loop(tid);
    for (int tid=0; tid<_nthreads; tid++)
      $wait(_threads[tid]);
  } /* End of omp for loop */

}