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Diffstat (limited to 'include/internal/benchmark/detail/catch_estimate_clock.hpp')
-rw-r--r-- | include/internal/benchmark/detail/catch_estimate_clock.hpp | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/include/internal/benchmark/detail/catch_estimate_clock.hpp b/include/internal/benchmark/detail/catch_estimate_clock.hpp new file mode 100644 index 00000000..055c5825 --- /dev/null +++ b/include/internal/benchmark/detail/catch_estimate_clock.hpp @@ -0,0 +1,113 @@ +/* + * Created by Joachim on 16/04/2019. + * Adapted from donated nonius code. + * + * Distributed under the Boost Software License, Version 1.0. (See accompanying + * file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) + */ + + // Environment measurement + +#ifndef TWOBLUECUBES_CATCH_DETAIL_ESTIMATE_CLOCK_HPP_INCLUDED +#define TWOBLUECUBES_CATCH_DETAIL_ESTIMATE_CLOCK_HPP_INCLUDED + +#include "../catch_clock.hpp" +#include "../catch_environment.hpp" +#include "catch_stats.hpp" +#include "catch_measure.hpp" +#include "catch_run_for_at_least.hpp" +#include "../catch_clock.hpp" + +#include <algorithm> +#include <iterator> +#include <tuple> +#include <vector> +#include <cmath> + +namespace Catch { + namespace Benchmark { + namespace Detail { + template <typename Clock> + std::vector<double> resolution(int k) { + std::vector<TimePoint<Clock>> times; + times.reserve(k + 1); + std::generate_n(std::back_inserter(times), k + 1, now<Clock>{}); + + std::vector<double> deltas; + deltas.reserve(k); + std::transform(std::next(times.begin()), times.end(), times.begin(), + std::back_inserter(deltas), + [](TimePoint<Clock> a, TimePoint<Clock> b) { return static_cast<double>((a - b).count()); }); + + return deltas; + } + + const auto warmup_iterations = 10000; + const auto warmup_time = std::chrono::milliseconds(100); + const auto minimum_ticks = 1000; + const auto warmup_seed = 10000; + const auto clock_resolution_estimation_time = std::chrono::milliseconds(500); + const auto clock_cost_estimation_time_limit = std::chrono::seconds(1); + const auto clock_cost_estimation_tick_limit = 100000; + const auto clock_cost_estimation_time = std::chrono::milliseconds(10); + const auto clock_cost_estimation_iterations = 10000; + + template <typename Clock> + int warmup() { + return run_for_at_least<Clock>(std::chrono::duration_cast<ClockDuration<Clock>>(warmup_time), warmup_seed, &resolution<Clock>) + .iterations; + } + template <typename Clock> + EnvironmentEstimate<FloatDuration<Clock>> estimate_clock_resolution(int iterations) { + auto r = run_for_at_least<Clock>(std::chrono::duration_cast<ClockDuration<Clock>>(clock_resolution_estimation_time), iterations, &resolution<Clock>) + .result; + return { + FloatDuration<Clock>(mean(r.begin(), r.end())), + classify_outliers(r.begin(), r.end()), + }; + } + template <typename Clock> + EnvironmentEstimate<FloatDuration<Clock>> estimate_clock_cost(FloatDuration<Clock> resolution) { + auto time_limit = std::min(resolution * clock_cost_estimation_tick_limit, FloatDuration<Clock>(clock_cost_estimation_time_limit)); + auto time_clock = [](int k) { + return Detail::measure<Clock>([k] { + for (int i = 0; i < k; ++i) { + volatile auto ignored = Clock::now(); + (void)ignored; + } + }).elapsed; + }; + time_clock(1); + int iters = clock_cost_estimation_iterations; + auto&& r = run_for_at_least<Clock>(std::chrono::duration_cast<ClockDuration<Clock>>(clock_cost_estimation_time), iters, time_clock); + std::vector<double> times; + int nsamples = static_cast<int>(std::ceil(time_limit / r.elapsed)); + times.reserve(nsamples); + std::generate_n(std::back_inserter(times), nsamples, [time_clock, &r] { + return static_cast<double>((time_clock(r.iterations) / r.iterations).count()); + }); + return { + FloatDuration<Clock>(mean(times.begin(), times.end())), + classify_outliers(times.begin(), times.end()), + }; + } + + template <typename Clock> + Environment<FloatDuration<Clock>> measure_environment() { + static Environment<FloatDuration<Clock>>* env = nullptr; + if (env) { + return *env; + } + + auto iters = Detail::warmup<Clock>(); + auto resolution = Detail::estimate_clock_resolution<Clock>(iters); + auto cost = Detail::estimate_clock_cost<Clock>(resolution.mean); + + env = new Environment<FloatDuration<Clock>>{ resolution, cost }; + return *env; + } + } // namespace Detail + } // namespace Benchmark +} // namespace Catch + +#endif // TWOBLUECUBES_CATCH_DETAIL_ESTIMATE_CLOCK_HPP_INCLUDED |