/* speed.c - speedtest */

#include <stdlib.h>
#include <stdio.h>
#include <sys/time.h>
#include <time.h>
#include <string.h>
#include <unistd.h>

#define N   10E6

/* number of cycles we are using per call */

long long cycles_last = 0;
long long cycles_worst = 0;
long long cycles_total = 0;
long long cycles_average = 0;

__inline__ unsigned long long cycles() {
  unsigned long long x;
  __asm__ volatile ("rdtsc\n\t" : "=A" (x));
  return x;
}

int main(int argc, char **argv) {
    int                i,j;
    struct timeval     tv_before;
    struct timeval     tv_after;
    unsigned long long t_before_ms, t_after_ms;
    unsigned long long before_clocks, after_clocks;
    int                t_ms;
    unsigned long long start_cycles;
    float              mips_cpu, mips_per_ec;

    gettimeofday(&tv_before, NULL);

    before_clocks = cycles();

    for(i=0; i<N; i++) {

            start_cycles = cycles();
            cycles_last = cycles() - start_cycles;
            cycles_total += cycles_last;

    }

    cycles_average =  cycles_total / N;
    after_clocks = cycles();
 gettimeofday(&tv_after, NULL);
    t_before_ms = 1000*tv_before.tv_sec + tv_before.tv_usec/1000;
    t_after_ms = 1000*tv_after.tv_sec + tv_after.tv_usec/1000;
    t_ms = t_after_ms - t_before_ms;

    mips_cpu = (after_clocks - before_clocks)/(1E3*t_ms);
    printf("CPUs:\t\t %5.2f MIPS\n", mips_cpu);
    printf("Used time:\t %d ms\n", t_ms);
    printf("Cycles_last:\t %lld\nCycles_avg:\t %lld\n", cycles_last, cycles_average);
    return 0;
}