/* speed.c
	purpose:  how fast are a half million sqrts.
	comp/link:
		gcc -o speed speed.c -lm
*/

#define NSQRTS	500000

#include <stdio.h>
#include <math.h>
#include <sys/time.h>
#include <unistd.h>

/******************************************************************************/
int main(int argc, char **argv)
{
	int i;
	double ival;
	double time1, time2;
	struct timeval tv1, tv2;
	struct timezone tz1, tz2;


	gettimeofday(&tv1, &tz1);
	for(i = 0; i < NSQRTS; i++)
		ival = sqrt((double)i);
	gettimeofday(&tv2, &tz2);

	/* printf("second %d, micro second %d\n", tv1.tv_sec, tv1.tv_usec); */
	/* printf("second %d, micro second %d\n", tv2.tv_sec, tv2.tv_usec); */

	time1 = (double)tv1.tv_sec + (double)tv1.tv_usec/1.0e6;
	time2 = (double)tv2.tv_sec + (double)tv2.tv_usec/1.0e6;
	printf("%d square roots in ... \n", NSQRTS);
	printf("time2 - time1 = %lf - %lf = %lf s\n",
		time2, time1, time2 - time1);
		
	return 0;

} /* main */