#include <sys/types.h>
#include <sys/time.h>
#include <stdio.h>

#define matSize 500
#define maxTest 10

double matA[matSize][matSize], matB[matSize][matSize], matC[matSize][matSize];
int main( int argc, char *argv[] )
{
    double sum;
    int    i, j, k, tests;
    struct timeval  tStart, tEnd;
    float   tLoop, t, rate;

    /*     Initialize the matrices */
    for (i=0; i<matSize; i++) {
	for (j=0; j<matSize; j++) {
	    matA[i][j] = 1.0 + i;
	    matB[i][j] = 1.0 + j;
	    matC[i][j] = 0.0;
	}
    }

    tLoop = 1.0e10;
    for (tests=0; tests<maxTest; tests++) {
	gettimeofday( &tStart, 0 );
	for (i=0; i<matSize; i++) {
	    for (j=0; j<matSize; j++) {
		sum = 0.0;
		for (k=0; k<matSize; k++) {
		    sum += matA[i][k] * matB[k][j];
		}
		matC[i][j] = sum;
	    }
	}
	gettimeofday( &tEnd, 0 );
	if (matC[i][j] < 0.0) printf( "failed basic sign test\n" );

	t = (tEnd.tv_sec - tStart.tv_sec) + 
	    1.0e-6 * (tEnd.tv_usec - tStart.tv_usec);
	if (t < tLoop) tLoop = t;
    }

    rate = (2.0 * matSize) * matSize * (matSize / tLoop);
    printf( "Time = %f\nRate = %f MFLOPS\n", tLoop, rate * 1.0e-6);

    return 0;
}