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benchmarks: report iterations per second instead of the inverse

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This commit is contained in:
Mickey Rose 2016-02-27 22:23:28 +01:00
parent 3fdc799e84
commit 02286bb7d1
1 changed files with 43 additions and 18 deletions
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61
benchmark/bench_framework.hpp
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@ -10,6 +10,7 @@
// stl
#include <chrono>
#include <cmath> // log10
#include <cstdio> // snprintf
#include <iostream>
#include <set>
@ -19,6 +20,12 @@
namespace benchmark {
template <typename T>
using milliseconds = std::chrono::duration<T, std::milli>;
template <typename T>
using seconds = std::chrono::duration<T>;
class test_case
{
protected:
@ -134,6 +141,29 @@ inline int handle_args(int argc, char** argv, mapnik::parameters & params)
} \
} \
struct big_number_fmt
{
int w;
double v;
const char* u;
big_number_fmt(int width, double value, int base = 1000)
: w(width), v(value), u("")
{
static const char* suffixes = "\0\0k\0M\0G\0T\0P\0E\0Z\0Y\0\0";
u = suffixes;
while (v > 1 && std::log10(v) >= width && u[2])
{
v /= base;
u += 2;
}
// adjust width for proper alignment without suffix
w += (u == suffixes);
}
};
template <typename T>
int run(T const& test_runner, std::string const& name)
{
@ -156,7 +186,8 @@ int run(T const& test_runner, std::string const& name)
auto opt_min_duration = test_runner.params().template get<double>("min-duration", 0.0);
std::chrono::duration<double> min_seconds(*opt_min_duration);
auto min_duration = std::chrono::duration_cast<decltype(elapsed)>(min_seconds);
std::size_t loops = 0;
auto num_iters = test_runner.iterations();
auto total_iters = 0;
if (test_runner.threads() > 0)
{
@ -170,7 +201,7 @@ int run(T const& test_runner, std::string const& name)
start = std::chrono::high_resolution_clock::now();
std::for_each(tg.begin(), tg.end(), [](value_type & t) {if (t->joinable()) t->join();});
elapsed = std::chrono::high_resolution_clock::now() - start;
loops = 1;
total_iters += num_iters;
}
else
{
@ -178,35 +209,29 @@ int run(T const& test_runner, std::string const& name)
do {
test_runner();
elapsed = std::chrono::high_resolution_clock::now() - start;
++loops;
total_iters += num_iters;
} while (elapsed < min_duration);
}
double iters = loops * test_runner.iterations();
double dur_total = std::chrono::duration<double, std::milli>(elapsed).count();
double dur_avg = dur_total / iters;
char iters_unit = ' ';
char msg[200];
if (iters >= 1e7) iters *= 1e-6, iters_unit = 'M';
else if (iters >= 1e4) iters *= 1e-3, iters_unit = 'k';
double dur_total = milliseconds<double>(elapsed).count();
big_number_fmt itersf(4, total_iters);
std::snprintf(msg, sizeof(msg),
"%-43s %3zu threads %4.0f%c iters %6.0f milliseconds",
"%-43s %3zu threads %*.0f%s iters %6.0f milliseconds",
name.c_str(),
test_runner.threads(),
iters, iters_unit,
itersf.w, itersf.v, itersf.u,
dur_total);
std::clog << msg;
// log average time per iteration, currently only for non-threaded runs
// log average # of iterations per second, currently only for
// non-threaded runs
if (test_runner.threads() == 0)
{
char unit = 'm';
if (dur_avg < 1e-5) dur_avg *= 1e+9, unit = 'p';
else if (dur_avg < 1e-2) dur_avg *= 1e+6, unit = 'n';
else if (dur_avg < 1e+1) dur_avg *= 1e+3, unit = 'u';
std::snprintf(msg, sizeof(msg), " %4.0f%cs/iter", dur_avg, unit);
auto elapsed_nonzero = std::max(elapsed, decltype(elapsed){1});
big_number_fmt ips(5, total_iters / seconds<double>(elapsed_nonzero).count());
std::snprintf(msg, sizeof(msg), " %*.0f%s i/s", ips.w, ips.v, ips.u);
std::clog << msg;
}