matrix.c

#include <stdio.h>

#define X_1 5
#define Y_1 5
#define X_2 5
#define Y_2 5
#define Z_1 5
#define Z_2 5


void mul()
{
  double m1[X_1][Y_1];
  double m2[Y_1][Y_2];
  double m3[Z_1][Z_2];

  int i,j,k;


  // warm up the cache
  for (i = 0; i < X_1; ++i)
  {
    for (j = 0; j < Y_2; ++j)
    {
      m1[i][j] = 1;
      m2[i][j] = 3;
      m3[i][j] = 0;
    }
  }

  int sum=0;
  for(i = 0; i < X_1; ++i)
  {
    for (j = 0; j < Y_2; ++j)
    {
      for (k = 0; k < Y_2; ++k)
      {
        sum = sum + m1[i][k] * m2[k][j];
      }
      m3[i][j] = sum;
      sum=0;
    }
  }

#ifdef PRINT
  for (i = 0; i < X_1; ++i)
  {
    for (j = 0; j < Y_2; ++j)
    {
      printf("%f\t", m3[i][j]);

    }
    printf("\n");
  }
#endif
}


int main(void)
{
  mul();
}