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libstdc++: Add performance test for atomic_flag [PR 46447]

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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.
This commit is contained in:
Jonathan Wakely 2020-12-16 11:51:42 +00:00
parent a2c2eec183
commit 3cee0c6562
1 changed files with 71 additions and 0 deletions
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libstdc++-v3/testsuite/performance/29_atomics/atomic_flag.cc Normal file
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// 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
// <http://www.gnu.org/licenses/>.
#include <atomic>
#include <testsuite_performance.h>
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;
}