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@dstebila dstebila/ds_benchmark.h

Last active Apr 29, 2020
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C macros for performance testing
/********************************************************************************************
* ds_benchmark.h: Macros for simple benchmarking of C code.
*
* See instructions for usage below.
* Software originally developed by Douglas Stebila.
* Most recent version at https://gist.github.com/dstebila/6980008ec98209ef6075
*
* This is free and unencumbered software released into the public domain.
*
* Anyone is free to copy, modify, publish, use, compile, sell, or
* distribute this software, either in source code form or as a compiled
* binary, for any purpose, commercial or non-commercial, and by any
* means.
*
* In jurisdictions that recognize copyright laws, the author or authors
* of this software dedicate any and all copyright interest in the
* software to the public domain. We make this dedication for the benefit
* of the public at large and to the detriment of our heirs and
* successors. We intend this dedication to be an overt act of
* relinquishment in perpetuity of all present and future rights to this
* software under copyright law.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* For more information, please refer to <http://unlicense.org>
********************************************************************************************/
/** \file ds_benchmark.h
* Macros for simple benchmarking of C code.
*/
#if 0
/* example code: timing two operations */
#include "ds_benchmark.h"
...
DEFINE_TIMER_VARIABLES
INITIALIZE_TIMER
START_TIMER
// your operation here
STOP_TIMER
START_TIMER
// another operation here
STOP_TIMER
FINALIZE_TIMER
PRINT_TIMER_HEADER
PRINT_TIMER_AVG("my operation")
PRINT_TIMER_FOOTER
/* example code: average multiple runs, run for e.g. 30 seconds */
#include "ds_benchmark.h"
...
PRINT_TIMER_HEADER
TIME_OPERATION_SECONDS(MyFunction(myarg1, myarg2, ...), "my operation", 30)
TIME_OPERATION_SECONDS(MyOtherFunction(myarg3), "my other operation", 30)
PRINT_TIMER_FOOTER
/* example code: average multiple runs, run for e.g. 100 iterations */
#include "ds_benchmark.h"
...
PRINT_TIMER_HEADER
TIME_OPERATION_ITERATIONS(MyFunction(myarg1, myarg2, ...), "my operation", 1000)
TIME_OPERATION_ITERATIONS(MyOtherFunction(myarg3), "my other operation", 100)
PRINT_TIMER_FOOTER
/* For most accurate results:
* - disable hyperthreading a.k.a. hardware multithreading
* (Linux instructions: http://bench.cr.yp.to/supercop.html)
* (Mac OS X instructions: Instruments -> Preferences -> CPUs -> uncheck "Hardware Multi-Threading"
* http://forums.macrumors.com/showthread.php?t=1484684)
* - disable TurboBoost
* (Linux instructions: http://bench.cr.yp.to/supercop.html)
* (Max OS X: use http://www.rugarciap.com/turbo-boost-switcher-for-os-x/)
* - run when the computer is idle (e.g., shut down all other applications, disable network access if possible, ...)
*/
/* On Raspberry Pi, you need to additionally define the macro _RASPBERRY_PI since
* the high-precision cycle count register is not available to user-space programs.
*/
#endif
#ifndef _DS_BENCHMARK_H
#define _DS_BENCHMARK_H
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#if !defined(_WIN32)
#include <sys/time.h>
#endif
#include <math.h>
#include <time.h>
#if defined(_WIN32)
#include <Windows.h>
int gettimeofday(struct timeval *tp, struct timezone *tzp) {
// Note: some broken versions only have 8 trailing zero's, the correct epoch has 9 trailing zero's
static const uint64_t EPOCH = ((uint64_t) 116444736000000000ULL);
SYSTEMTIME system_time;
FILETIME file_time;
uint64_t time;
GetSystemTime(&system_time);
SystemTimeToFileTime(&system_time, &file_time);
time = ((uint64_t) file_time.dwLowDateTime);
time += ((uint64_t) file_time.dwHighDateTime) << 32;
tp->tv_sec = (long) ((time - EPOCH) / 10000000L);
tp->tv_usec = (long) (system_time.wMilliseconds * 1000);
return 0;
}
#endif
static uint64_t _bench_rdtsc(void) {
#if defined(_WIN32) || defined(_WIN64)
return __rdtsc();
#elif defined(__i586__) || defined(__amd64__)
uint64_t x;
__asm__ volatile(".byte 0x0f, 0x31"
: "=A"(x));
return x;
#elif defined(__arm__) && !defined(_RASPBERRY_PI)
/* Use the ARM performance counters. */
unsigned int value;
/* Read CCNT Register */
asm volatile("mrc p15, 0, %0, c9, c13, 0\t\n"
: "=r"(value));
return value;
#else
#define USING_TIME_RATHER_THAN_CYCLES
struct timespec time;
clock_gettime(CLOCK_REALTIME, &time);
return (int64_t)(time.tv_sec * 1e9 + time.tv_nsec);
#endif
}
#if defined(__arm__) && !defined(_RASPBERRY_PI)
static void _bench_init_perfcounters(int32_t do_reset, int32_t enable_divider) {
/* In general enable all counters (including cycle counter) */
int32_t value = 1;
/* Peform reset */
if (do_reset) {
value |= 2; /* reset all counters to zero */
value |= 4; /* reset cycle counter to zero */
}
if (enable_divider)
value |= 8; /* enable "by 64" divider for CCNT */
value |= 16;
/* Program the performance-counter control-register */
asm volatile("mcr p15, 0, %0, c9, c12, 0\t\n" ::"r"(value));
/* Enable all counters */
asm volatile("mcr p15, 0, %0, c9, c12, 1\t\n" ::"r"(0x8000000f));
/* Clear overflows */
asm volatile("mcr p15, 0, %0, c9, c12, 3\t\n" ::"r"(0x8000000f));
}
#endif
#define DEFINE_TIMER_VARIABLES \
volatile uint64_t _bench_cycles_start, _bench_cycles_end; \
uint64_t _bench_cycles_cumulative = 0; \
int64_t _bench_cycles_diff; \
struct timeval _bench_timeval_start, _bench_timeval_end; \
uint64_t _bench_iterations, _bench_time_cumulative; \
double _bench_cycles_x, _bench_cycles_mean, _bench_cycles_delta, _bench_cycles_M2, _bench_cycles_stdev; \
double _bench_time_x, _bench_time_mean, _bench_time_delta, _bench_time_M2, _bench_time_stdev;
#if defined(__arm__) && !defined(_RASPBERRY_PI)
#define INITIALIZE_TIMER \
_bench_init_perfcounters(1, 0); \
_bench_iterations = 0; \
_bench_cycles_mean = 0.0; \
_bench_cycles_M2 = 0.0; \
_bench_time_cumulative = 0; \
_bench_time_mean = 0.0; \
_bench_time_M2 = 0.0;
#else
#define INITIALIZE_TIMER \
_bench_iterations = 0; \
_bench_cycles_mean = 0.0; \
_bench_cycles_M2 = 0.0; \
_bench_time_cumulative = 0; \
_bench_time_mean = 0.0; \
_bench_time_M2 = 0.0;
#endif
#define START_TIMER \
gettimeofday(&_bench_timeval_start, NULL); \
_bench_cycles_start = _bench_rdtsc();
// Mean and population standard deviation are calculated in an online way using the algorithm in
// http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance#Online_algorithm
#define STOP_TIMER \
_bench_cycles_end = _bench_rdtsc(); \
gettimeofday(&_bench_timeval_end, NULL); \
_bench_iterations += 1; \
if (_bench_cycles_end < _bench_cycles_start) { \
_bench_cycles_end += (uint64_t) 1 << 32; \
} \
_bench_cycles_diff = _bench_cycles_end; \
_bench_cycles_diff -= _bench_cycles_start; \
_bench_cycles_cumulative += _bench_cycles_diff; \
_bench_cycles_x = (double) (_bench_cycles_diff); \
_bench_cycles_delta = _bench_cycles_x - _bench_cycles_mean; \
_bench_cycles_mean += _bench_cycles_delta / (double) _bench_iterations; \
_bench_cycles_M2 += _bench_cycles_delta * (_bench_cycles_x - _bench_cycles_mean); \
_bench_time_x = (double) ((_bench_timeval_end.tv_sec * 1000000 + _bench_timeval_end.tv_usec) - (_bench_timeval_start.tv_sec * 1000000 + _bench_timeval_start.tv_usec)); \
_bench_time_delta = _bench_time_x - _bench_time_mean; \
_bench_time_mean += _bench_time_delta / (double) _bench_iterations; \
_bench_time_M2 += _bench_time_delta * (_bench_time_x - _bench_time_mean); \
_bench_time_cumulative += _bench_time_x;
#define FINALIZE_TIMER \
if (_bench_iterations == 2) { \
_bench_cycles_stdev = 0.0; \
} else { \
_bench_cycles_stdev = sqrt(_bench_cycles_M2 / (double) _bench_iterations); \
} \
if (_bench_iterations == 2) { \
_bench_time_stdev = 0.0; \
} else { \
_bench_time_stdev = sqrt(_bench_time_M2 / (double) _bench_iterations); \
}
#define PRINT_CURRENT_TIME \
{ \
char _bench_time_buff[20]; \
time_t _bench_time_now = time(0); \
strftime(_bench_time_buff, 20, "%Y-%m-%d %H:%M:%S", localtime(&_bench_time_now)); \
printf("%s", _bench_time_buff); \
}
#ifdef USING_TIME_RATHER_THAN_CYCLES
#define HIGH_PREC_HEADER "High-prec time (ns): mean"
#else
#define HIGH_PREC_HEADER "CPU cycles: mean "
#endif
#define PRINT_TIMER_HEADER \
printf("Started at "); \
PRINT_CURRENT_TIME \
printf("\n"); \
printf("%-30s | %10s | %14s | %15s | %10s | %25s | %10s\n", "Operation ", "Iterations", "Total time (s)", "Time (us): mean", "pop. stdev", HIGH_PREC_HEADER, "pop. stdev"); \
printf("%-30s | %10s:| %14s:| %15s:| %10s:| %25s:| %10s:\n", "------------------------------", "----------", "--------------", "---------------", "----------", "-------------------------", "----------");
/* colons are used in above to right-align cell contents in Markdown */
#define PRINT_TIMER_FOOTER \
printf("Ended at "); \
PRINT_CURRENT_TIME \
printf("\n");
#define PRINT_TIMER_AVG(op_name) \
printf("%-30s | %10" PRIu64 " | %14.3f | %15.3f | %10.3f | %25.0f | %10.0f\n", (op_name), _bench_iterations, ((double) _bench_time_cumulative) / 1000000.0, _bench_time_mean, _bench_time_stdev, ((double) _bench_cycles_cumulative) / (double) _bench_iterations, _bench_cycles_stdev);
#define TIME_OPERATION_ITERATIONS(op, op_name, it) \
{ \
DEFINE_TIMER_VARIABLES \
INITIALIZE_TIMER \
for (int i = 0; i < (it); i++) { \
START_TIMER { op; } \
STOP_TIMER \
} \
FINALIZE_TIMER \
PRINT_TIMER_AVG(op_name) \
}
#define TIME_OPERATION_SECONDS(op, op_name, secs) \
{ \
DEFINE_TIMER_VARIABLES \
INITIALIZE_TIMER \
uint64_t _bench_time_goal_usecs = 1000000 * secs; \
while (_bench_time_cumulative < _bench_time_goal_usecs) { \
START_TIMER { op; } \
STOP_TIMER \
} \
FINALIZE_TIMER \
PRINT_TIMER_AVG(op_name) \
}
#endif
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