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/* Skeleton for benchmark programs.
Copyright (C) 2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <string.h>
#include <stdint.h>
#include <stdio.h>
#include <time.h>
#include <inttypes.h>
#define TIMESPEC_AFTER(a, b) \
(((a).tv_sec == (b).tv_sec) ? \
((a).tv_nsec > (b).tv_nsec) : \
((a).tv_sec > (b).tv_sec))
int
main (int argc, char **argv)
{
unsigned long i, k;
uint64_t total = 0, max = 0, min = 0x7fffffffffffffff;
struct timespec start, end, runtime;
memset (&runtime, 0, sizeof (runtime));
memset (&start, 0, sizeof (start));
memset (&end, 0, sizeof (end));
clock_getres (CLOCK_PROCESS_CPUTIME_ID, &start);
/* Measure 1000 times the resolution of the clock. So for a 1ns resolution
clock, we measure 1000 iterations of the function call at a time.
Measurements close to the minimum clock resolution won't make much sense,
but it's better than having nothing at all. */
unsigned long iters = 1000 * start.tv_nsec;
/* Run for approxmately DURATION seconds. */
clock_gettime (CLOCK_MONOTONIC_RAW, &runtime);
runtime.tv_sec += DURATION;
double d_total_i = 0;
while (1)
{
for (i = 0; i < NUM_SAMPLES; i++)
{
clock_gettime (CLOCK_PROCESS_CPUTIME_ID, &start);
for (k = 0; k < iters; k++)
BENCH_FUNC(i);
clock_gettime (CLOCK_PROCESS_CPUTIME_ID, &end);
uint64_t cur = (end.tv_nsec - start.tv_nsec
+ ((end.tv_sec - start.tv_sec)
* (uint64_t) 1000000000));
if (cur > max)
max = cur;
if (cur < min)
min = cur;
total += cur;
d_total_i += iters;
}
struct timespec curtime;
memset (&curtime, 0, sizeof (curtime));
clock_gettime (CLOCK_MONOTONIC_RAW, &curtime);
if (TIMESPEC_AFTER (curtime, runtime))
goto done;
}
double d_total_s;
double d_iters;
done:
d_total_s = total * 1e-9;
d_iters = iters;
printf (FUNCNAME ": ITERS:%g: TOTAL:%gs, MAX:%gns, MIN:%gns, %g iter/s\n",
d_total_i, d_total_s, max / d_iters, min / d_iters,
d_total_i / d_total_s);
return 0;
}
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