Little benchmark

bench.c

/* Any copyright is dedicated to the Public Domain.
* http://creativecommons.org/publicdomain/zero/1.0/
*
* Compile using |gcc -O0 bench.c -o bench|
*/
#include <stdio.h>
#include <sys/time.h>

#define TIMES 10000000

int main(int argc, char *argv[])
{
  struct timeval start;
  struct timeval end;

  while (1) {
    gettimeofday(&start, NULL);
    // tight loop
    unsigned long i;
    for (i = 0; i < TIMES; ++i);
    gettimeofday(&end, NULL);
    printf("speed %g loop/us\n",
           (double)TIMES / ((end.tv_sec-start.tv_sec)*1000000 +
                            end.tv_usec - start.tv_usec));
  }
  return 0;
}