1 #include <stdio.h>
  2 #include <stdlib.h>
  3 
  4 void mxv( int m, int n, double * restrict a, double * restrict b, double * restrict c );
  5 
  6 int main( int argc, char *argv[] ) {
  7     double *a, *b, *c;
  8     int i, j, m, n, k, loopLimit;
  9     
 10     if (argc != 4) {
 11         fputs( "usage: test <loopLimit> <m> <n>", stderr );
 12         exit( EXITFAILURE );
 13     }
 14     
 15     loopLimit = (int)strtol( argv[1], NULL, 10 );
 16     m = (int)strtol( argv[2], NULL, 10 );
 17     n = (int)strtol( argv[3], NULL, 10 );
 18     
 19     if ( (a=(double *)malloc(m*sizeof(double))) == NULL )
 20         perror( "memory allocation for a" );
 21     if ( (b=(double *)malloc(m*n*sizeof(double))) == NULL )
 22         perror( "memory allocation for b" );
 23     if ( (c=(double *)malloc(n*sizeof(double))) == NULL )
 24         perror( "memory allocation for c" );
 25     
 26     for (j=0; j<n; j++)
 27         c[ j ] = 2.0;
 28     for (i=0; i<m; i++)
 29         for (j=0; j<n; j++)
 30             b[ i*n + j ] = i;
 31     
 32     for (k=0; k<loopLimit; k++)
 33         (void) mxv( m, n, a, b, c );
 34     
 35     free(a); free(b); free(c);
 36     return EXITSUCCESS;
 37 }
 38 
 39 void mxv( int m, int n, double * restrict a, double * restrict b, double * restrict c ) {
 40     int i, j;
 41 
 42 #pragma omp parallel for default(none) shared( m, n, a, b, c ) private( i, j )
 43         
 44     for (i=0; i<m; i++) {
 45         a[ i ] = 0.0;
 46         for (j=0; j<n; j++)
 47             a[ i ] += b[ i*n + j ] * c[ j ];
 48     }
 49     // end of omp parallel for
 50 }