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#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include <sys/time.h>
#include <sys/types.h>
#include <cpucycles.h>
#define TIMINGS 63
static long long t[TIMINGS+1];
static void t_print(void)
{
long long median = 0;
long long i,j;
for (i = 0;i < TIMINGS;++i)
t[i] = t[i+1]-t[i];
for (j = 0;j < TIMINGS;++j) {
long long belowj = 0;
long long abovej = 0;
for (i = 0;i < TIMINGS;++i) if (t[i] < t[j]) ++belowj;
for (i = 0;i < TIMINGS;++i) if (t[i] > t[j]) ++abovej;
if (belowj*2 < TIMINGS && abovej*2 < TIMINGS) {
median = t[j];
break;
}
}
printf(" %lld ",median);
for (i = 0;i < TIMINGS;++i)
printf("%+lld",t[i]-median);
printf("\n");
fflush(stdout);
}
static long long microseconds(void)
{
struct timeval t;
long long result;
gettimeofday(&t,(struct timezone *) 0);
result = t.tv_sec;
result *= 1000000;
result += t.tv_usec;
return result;
}
static volatile int v;
static void measure_cpucycles(void)
{
long long loops,i,j;
printf("cpucycles persecond %lld\n",cpucycles_persecond());
printf("cpucycles implementation %s\n",cpucycles_implementation());
for (i = 0;i <= TIMINGS;++i)
t[i] = cpucycles();
printf("cpucycles median"); t_print();
for (loops = 1024;loops <= 1048576;loops *= 2) {
long long t00,t01,t10,t11;
long long m0,m1;
double ratiobelow,ratioabove;
t00 = cpucycles();
m0 = microseconds();
t01 = cpucycles();
for (j = 0;j < loops;++j) v = 0;
t10 = cpucycles();
m1 = microseconds();
t11 = cpucycles();
if (t01 < t00) continue;
if (t10 < t01) continue;
if (t11 < t10) continue;
if (m1 <= m0+2) continue;
ratiobelow = floor((1000000.0*(t10-t01))/(m1+1-m0));
ratioabove = ceil((1000000.0*(t11-t00))/(m1-m0-1));
printf("cpucycles observed persecond %.0lf...%.0lf with %lld loops %lld microseconds\n",ratiobelow,ratioabove,loops,m1-m0);
}
}
int main(int argc,char **argv)
{
cpucycles_tracesetup();
printf("cpucycles version %s\n",cpucycles_version());
measure_cpucycles();
return 0;
}
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