From 3cee0c6562e5d8df69a9d6ad613a6f3edcfcc797 Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Wed, 16 Dec 2020 11:51:42 +0000 Subject: [PATCH] libstdc++: Add performance test for atomic_flag [PR 46447] This adds a test to compare the performance of std::atomic_flag with similar operations on std::atomic_uchar and std::atomic_int. libstdc++-v3/ChangeLog: PR libstdc++/46447 * testsuite/performance/29_atomics/atomic_flag.cc: New test. --- .../performance/29_atomics/atomic_flag.cc | 71 +++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 libstdc++-v3/testsuite/performance/29_atomics/atomic_flag.cc diff --git a/libstdc++-v3/testsuite/performance/29_atomics/atomic_flag.cc b/libstdc++-v3/testsuite/performance/29_atomics/atomic_flag.cc new file mode 100644 index 00000000000..af1a269a0e0 --- /dev/null +++ b/libstdc++-v3/testsuite/performance/29_atomics/atomic_flag.cc @@ -0,0 +1,71 @@ +// Copyright (C) 2009-2020 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This 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 General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// . + + +#include +#include + +volatile std::atomic_flag af; +volatile std::atomic_uchar ac; +volatile std::atomic_int ai; + +int main() +{ + using namespace __gnu_test; + time_counter time; + resource_counter resource; + + const int n = 100000000; + + start_counters(time, resource); + for (int i = 0; i < n; ++i) + af.test_and_set(); + stop_counters(time, resource); + report_performance(__FILE__, "atomic_flag::test_and_set()", time, resource); + + start_counters(time, resource); + for (int i = 0; i < n; ++i) + af.clear(); + stop_counters(time, resource); + report_performance(__FILE__, "atomic_flag::clear()", time, resource); + + start_counters(time, resource); + for (int i = 0; i < n; ++i) + ac |= 1; + stop_counters(time, resource); + report_performance(__FILE__, "atomic_uchar::operator|=(1)", time, resource); + + start_counters(time, resource); + for (int i = 0; i < n; ++i) + ac = 0; + stop_counters(time, resource); + report_performance(__FILE__, "atomic_flag::operator=(0)", time, resource); + + start_counters(time, resource); + for (int i = 0; i < n; ++i) + ai |= 1; + stop_counters(time, resource); + report_performance(__FILE__, "atomic_int::operator|=(1)", time, resource); + + start_counters(time, resource); + for (int i = 0; i < n; ++i) + ai = 0; + stop_counters(time, resource); + report_performance(__FILE__, "atomic_int::operator=(0)", time, resource); + + return 0; +} -- 2.30.2