A recent change caused a performance regression. This restores the
previous performance and adds a performance test.
* scripts/check_performance: Allow tests to choose a -std flag.
* src/c++17/memory_resource.cc (bitset::get_first_unset()): Use local
variables of the right types. Call update_next_word() unconditionally.
* testsuite/20_util/unsynchronized_pool_resource/cons.cc: New test.
* testsuite/performance/20_util/memory_resource/pools.cc: New test.
* testsuite/util/testsuite_performance.h (time_counter): Allow
timer to be restarted.
Tested x86_64-linux, committed to trunk.
commit da6a822ba7b4aec1fa2fe9994e75539eec55f80e
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Thu Nov 15 00:01:53 2018 +0000
Optimize pool resource allocation
A recent change caused a performance regression. This restores the
previous performance and adds a performance test.
* scripts/check_performance: Allow tests to choose a -std flag.
* src/c++17/memory_resource.cc (bitset::get_first_unset()): Use
local
variables of the right types. Call update_next_word()
unconditionally.
* testsuite/20_util/unsynchronized_pool_resource/cons.cc: New test.
* testsuite/performance/20_util/memory_resource/pools.cc: New test.
* testsuite/util/testsuite_performance.h (time_counter): Allow
timer to be restarted.
diff --git a/libstdc++-v3/scripts/check_performance
b/libstdc++-v3/scripts/check_performance
index d196355bd44..3fa927480c9 100755
--- a/libstdc++-v3/scripts/check_performance
+++ b/libstdc++-v3/scripts/check_performance
@@ -44,6 +44,8 @@ do
TESTNAME=$SRC_DIR/testsuite/$NAME
FILE_NAME="`basename $NAME`"
FILE_NAME="`echo $FILE_NAME | sed 's/.cc//g'`"
+ ORIG_CXX="$CXX"
+ CXX="$CXX `sed -n 's/.* STD=/-std=/p' $TESTNAME`"
# TEST_S == single thread
# TEST_B == do both single and multi-thread
@@ -90,6 +92,7 @@ do
mv tmp.$FILE_NAME $FILE_NAME.xml
fi
fi
+ CXX="$ORIG_CXX"
done
exit 0
diff --git a/libstdc++-v3/src/c++17/memory_resource.cc
b/libstdc++-v3/src/c++17/memory_resource.cc
index 605bdd53950..79c1665146d 100644
--- a/libstdc++-v3/src/c++17/memory_resource.cc
+++ b/libstdc++-v3/src/c++17/memory_resource.cc
@@ -335,17 +335,16 @@ namespace pmr
size_type get_first_unset() noexcept
{
- if (_M_next_word < nwords())
+ const size_type wd = _M_next_word;
+ if (wd < nwords())
{
- const size_type n = std::__countr_one(_M_words[_M_next_word]);
+ const size_type n = std::__countr_one(_M_words[wd]);
if (n < bits_per_word)
{
const word bit = word(1) << n;
- _M_words[_M_next_word] |= bit;
- const size_t res = (_M_next_word * bits_per_word) + n;
- if (n == (bits_per_word - 1))
- update_next_word();
- return res;
+ _M_words[wd] |= bit;
+ update_next_word();
+ return (wd * bits_per_word) + n;
}
}
return size_type(-1);
diff --git
a/libstdc++-v3/testsuite/20_util/unsynchronized_pool_resource/cons.cc
b/libstdc++-v3/testsuite/20_util/unsynchronized_pool_resource/cons.cc
new file mode 100644
index 00000000000..14519ba1d00
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/unsynchronized_pool_resource/cons.cc
@@ -0,0 +1,80 @@
+// Copyright (C) 2018 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/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do run { target c++17 } }
+
+#include <memory_resource>
+#include <testsuite_hooks.h>
+#include <testsuite_allocator.h>
+
+void
+test01()
+{
+ __gnu_test::memory_resource test_mr1, test_mr2;
+ __gnu_test::default_resource_mgr mgr(&test_mr1);
+
+ const std::pmr::pool_options opts{1, 2};
+ using std::pmr::unsynchronized_pool_resource;
+
+ unsynchronized_pool_resource p1 = {opts, &test_mr2};
+ VERIFY( p1.upstream_resource() == &test_mr2 );
+ unsynchronized_pool_resource p2;
+ VERIFY( p2.upstream_resource() == std::pmr::get_default_resource() );
+ unsynchronized_pool_resource p3{&test_mr2};
+ VERIFY( p3.upstream_resource() == &test_mr2 );
+ unsynchronized_pool_resource p4{opts};
+ VERIFY( p4.upstream_resource() == std::pmr::get_default_resource() );
+
+ static_assert(!std::is_copy_constructible_v<unsynchronized_pool_resource>);
+ static_assert(!std::is_copy_assignable_v<unsynchronized_pool_resource>);
+ static_assert(std::is_destructible_v<unsynchronized_pool_resource>);
+}
+
+void
+test02()
+{
+ __gnu_test::memory_resource test_mr1, test_mr2;
+ __gnu_test::default_resource_mgr mgr(&test_mr1);
+
+ const std::pmr::pool_options opts{1, 2};
+
+ struct derived : std::pmr::unsynchronized_pool_resource
+ {
+ using unsynchronized_pool_resource::unsynchronized_pool_resource;
+ };
+
+ derived p1 = {opts, &test_mr2};
+ VERIFY( p1.upstream_resource() == &test_mr2 );
+ derived p2;
+ VERIFY( p2.upstream_resource() == std::pmr::get_default_resource() );
+ derived p3{&test_mr2};
+ VERIFY( p3.upstream_resource() == &test_mr2 );
+ derived p4{opts};
+ VERIFY( p4.upstream_resource() == std::pmr::get_default_resource() );
+
+ static_assert(!std::is_copy_constructible_v<derived>);
+ static_assert(!std::is_copy_assignable_v<derived>);
+ static_assert(std::is_destructible_v<derived>);
+}
+
+int
+main()
+{
+ test01();
+ test02();
+}
diff --git
a/libstdc++-v3/testsuite/performance/20_util/memory_resource/pools.cc
b/libstdc++-v3/testsuite/performance/20_util/memory_resource/pools.cc
new file mode 100644
index 00000000000..77f37fe63b2
--- /dev/null
+++ b/libstdc++-v3/testsuite/performance/20_util/memory_resource/pools.cc
@@ -0,0 +1,114 @@
+// 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/>.
+
+// Override the -std flag in the check_performance script: STD=gnu++17
+
+#include <memory_resource>
+#include <list>
+#include <string>
+#include <testsuite_performance.h>
+
+struct size16 { char c[16]; };
+struct size32 { char c[32]; };
+struct size64 { char c[64]; };
+struct size128 { char c[128]; };
+
+// Insert and remove elements of various sizes in std::list containers.
+// If report=true the function will measure and report the total performance
+// including the time taken to destroy the lists and deallocate everything.
+// If dest=false the function will measure and report the performance of
+// insert/remove operations only, not the destruction of the lists.
+void
+populate_lists(std::pmr::memory_resource* r, std::string name, bool dest,
+ int kmax = 100)
+{
+ name += " std::list push/pop";
+ if (dest)
+ name += "/destroy";
+
+ std::pmr::list<int> l4(r);
+ std::pmr::list<size16> l16(r);
+ std::pmr::list<size32> l32(r);
+ std::pmr::list<size64> l64(r);
+ std::pmr::list<size128> l128(r);
+
+ using namespace __gnu_test;
+ time_counter time;
+ resource_counter resource;
+ start_counters(time, resource);
+
+ const int imax = 1000;
+ const int jmax = 100;
+ for (int k = 0; k < kmax; ++k)
+ {
+ for (int i = 0; i < imax; ++i)
+ {
+ for (int j = 0; j < jmax; ++j)
+ {
+ l4.emplace_back();
+ l16.emplace_back();
+ l32.emplace_back();
+ l64.emplace_back();
+ l128.emplace_back();
+ }
+ l4.pop_front();
+ l16.pop_front();
+ l32.pop_front();
+ l64.pop_front();
+ l128.pop_front();
+ }
+
+ if (!dest)
+ time.stop();
+
+ // Deallocate everything:
+ l4.clear();
+ l16.clear();
+ l32.clear();
+ l64.clear();
+ l128.clear();
+
+ if (!dest)
+ time.restart();
+ }
+
+ stop_counters(time, resource);
+
+ report_performance(__FILE__, name.c_str(), time, resource);
+ clear_counters(time, resource);
+}
+
+int main()
+{
+ std::pmr::memory_resource* newdel = std::pmr::new_delete_resource();
+ std::pmr::unsynchronized_pool_resource pool;
+
+ for (auto b : { false, true })
+ {
+ // Start with an empty set of pools:
+ pool.release();
+
+ populate_lists(newdel, "new_delete 1", b);
+ populate_lists(newdel, "new_delete 2", b);
+ populate_lists(newdel, "new_delete 3", b);
+
+ populate_lists(&pool, "unsync pool 1", b);
+ // Destroy pools and start fresh:
+ pool.release();
+ populate_lists(&pool, "unsync pool 2", b);
+ // Do not destroy pools, reuse allocated memory:
+ populate_lists(&pool, "unsync pool 3", b);
+ }
+}
diff --git a/libstdc++-v3/testsuite/util/testsuite_performance.h
b/libstdc++-v3/testsuite/util/testsuite_performance.h
index 3dfd471221d..38ec35d4c45 100644
--- a/libstdc++-v3/testsuite/util/testsuite_performance.h
+++ b/libstdc++-v3/testsuite/util/testsuite_performance.h
@@ -79,10 +79,12 @@ namespace __gnu_test
clock_t elapsed_end;
tms tms_begin;
tms tms_end;
+ std::size_t splits[3];
public:
explicit
- time_counter() : elapsed_begin(), elapsed_end(), tms_begin(), tms_end()
+ time_counter()
+ : elapsed_begin(), elapsed_end(), tms_begin(), tms_end(), splits()
{ }
void
@@ -92,6 +94,7 @@ namespace __gnu_test
elapsed_end = clock_t();
tms_begin = tms();
tms_end = tms();
+ splits[0] = splits[1] = splits[2] = 0;
}
void
@@ -113,17 +116,29 @@ namespace __gnu_test
std::__throw_runtime_error("time_counter::stop");
}
+ void
+ restart()
+ {
+ splits[0] += (elapsed_end - elapsed_begin);
+ splits[1] += (tms_end.tms_utime - tms_begin.tms_utime);
+ splits[2] += (tms_end.tms_stime - tms_begin.tms_stime);
+ elapsed_begin = times(&tms_begin);
+ const clock_t err = clock_t(-1);
+ if (elapsed_begin == err)
+ std::__throw_runtime_error("time_counter::restart");
+ }
+
std::size_t
real_time() const
- { return elapsed_end - elapsed_begin; }
+ { return (elapsed_end - elapsed_begin) + splits[0]; }
std::size_t
user_time() const
- { return tms_end.tms_utime - tms_begin.tms_utime; }
+ { return (tms_end.tms_utime - tms_begin.tms_utime) + splits[1]; }
std::size_t
system_time() const
- { return tms_end.tms_stime - tms_begin.tms_stime; }
+ { return (tms_end.tms_stime - tms_begin.tms_stime) + splits[1]; }
};
class resource_counter
