Ajay Mohan / Rasperf | GitLab

Commit 741a26865c0ebadb7d27b1d33ced2dd55a4cc07f

Authored by Aravind Kumar 9 years ago

1 parent 91a330bc1a

Exists in master

CPU Measurement # 2 loop overhead

Showing 1 changed file with 2 additions and 2 deletions Inline Diff

cpu/loop_overhead_time.c

#include <stdio.h>	1		1	#include <stdio.h>
	2		2
int main()	3		3	int main()
{	4		4	{
int time1, time2, sum=0;	5		5	int time1, time2, sum=0;
int i;	6		6	int i;
int avg = 0;	7		7	int avg = 0;
asm volatile("mrc p15, 0, %0, c9, c14, 0" : "=r" (i));	8		8	asm volatile("mrc p15, 0, %0, c9, c14, 0" : "=r" (i));
	9		9
while(sum < 100) {	10		10	while(sum < 100) {
asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (time1));	11		11	asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (time1));
for (i = 0; i < 1000; i++);	12		12	for (i = 0; i < 1000; i++);
asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (time2));	13		13	asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (time2));
sum++;	14		14	avg = (time2 - time1 - 5);
avg += (time2 - time1 - 5);	15
printf("Loop overhead: %u\n", avg/(1000));	16		15	printf("Loop overhead: %u\n", avg/(1000));
			16	sum++;
}	17		17	}