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0cd794d486
While implementing this feature and its associated LWG issues it turns out - LWG3316 Correctly define epoch for utc_clock / utc_timepoint only added non-normative wording to the standard. Implements parts of: - P0355 Extending <chrono> to Calendars and Time Zones - P1361 Integration of chrono with text formatting - LWG3359 <chrono> leap second support should allow for negative leap seconds
61 lines
2.3 KiB
C++
61 lines
2.3 KiB
C++
//===----------------------------------------------------------------------===//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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// UNSUPPORTED: c++03, c++11, c++14, c++17
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// UNSUPPORTED: no-filesystem, no-localization, no-tzdb
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// XFAIL: libcpp-has-no-experimental-tzdb
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// XFAIL: availability-tzdb-missing
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#include <chrono>
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#include "benchmark/benchmark.h"
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// Benchmarks the performance of the UTC <-> system time conversions. These
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// operations determine the sum of leap second insertions at a specific time.
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static void BM_from_sys(benchmark::State& state) {
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std::chrono::sys_days date{std::chrono::July / 1 / state.range(0)};
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for (auto _ : state)
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benchmark::DoNotOptimize(std::chrono::utc_clock::from_sys(date));
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}
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BENCHMARK(BM_from_sys)
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->Arg(1970) // before the first leap seconds
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->Arg(1979) // in the first half of inserted leap seconds
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->Arg(1993) // in the second half of inserted leap seconds
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->Arg(2100); // after the last leap second
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BENCHMARK(BM_from_sys)->Arg(1970)->Arg(1979)->Arg(1993)->Arg(2100)->Threads(4);
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BENCHMARK(BM_from_sys)->Arg(1970)->Arg(1979)->Arg(1993)->Arg(2100)->Threads(16);
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static void BM_to_sys(benchmark::State& state) {
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// 59 sec offset means we pass th UTC offset for the leap second; assuming
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// there won't be more than 59 leap seconds ever.
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std::chrono::utc_seconds date{
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std::chrono::sys_days{std::chrono::July / 1 / state.range(0)}.time_since_epoch() + std::chrono::seconds{59}};
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for (auto _ : state)
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benchmark::DoNotOptimize(std::chrono::utc_clock::to_sys(date));
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}
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BENCHMARK(BM_to_sys)
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->Arg(1970) // before the first leap seconds
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->Arg(1979) // in the first half of inserted leap seconds
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->Arg(1993) // in the second half of inserted leap seconds
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->Arg(2100); // after the last leap second
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BENCHMARK(BM_to_sys)->Arg(1970)->Arg(1979)->Arg(1993)->Arg(2100)->Threads(4);
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BENCHMARK(BM_to_sys)->Arg(1970)->Arg(1979)->Arg(1993)->Arg(2100)->Threads(16);
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int main(int argc, char** argv) {
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benchmark::Initialize(&argc, argv);
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if (benchmark::ReportUnrecognizedArguments(argc, argv))
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return 1;
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benchmark::RunSpecifiedBenchmarks();
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}
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