re PR libstdc++/71181 (Reserving in unordered_map doesn't reserve enough)
2016-06-20 François Dumont <fdumont@gcc.gnu.org> PR libstdc++/71181 * include/tr1/hashtable_policy.h (_Prime_rehash_policy::_M_next_bkt): Make past-the-end iterator dereferenceable to avoid check on lower_bound result. (_Prime_rehash_policy::_M_bkt_for_elements): Call latter. (_Prime_rehash_policy::_M_need_rehash): Likewise. * src/c++11/hashtable_c++0x.cc (_Prime_rehash_policy::_M_next_bkt): Always return a value greater than input value. Set _M_next_resize to max value when reaching highest prime number. * src/shared/hashtable-aux.cc (__prime_list): Add comment about sentinel being now useless. * testsuite/23_containers/unordered_set/hash_policy/71181.cc: New. * testsuite/23_containers/unordered_set/hash_policy/power2_rehash.cc (test02): New. * testsuite/23_containers/unordered_set/hash_policy/prime_rehash.cc: New. * testsuite/23_containers/unordered_set/hash_policy/rehash.cc: Fix indentation. From-SVN: r237617
This commit is contained in:
François Dumont
parent
3947cf1919
commit
29dbb034cb
@ -1,3 +1,23 @@
|
||||
2016-06-20 François Dumont <fdumont@gcc.gnu.org>
|
||||
|
||||
PR libstdc++/71181
|
||||
* include/tr1/hashtable_policy.h
|
||||
(_Prime_rehash_policy::_M_next_bkt): Make past-the-end iterator
|
||||
dereferenceable to avoid check on lower_bound result.
|
||||
(_Prime_rehash_policy::_M_bkt_for_elements): Call latter.
|
||||
(_Prime_rehash_policy::_M_need_rehash): Likewise.
|
||||
* src/c++11/hashtable_c++0x.cc (_Prime_rehash_policy::_M_next_bkt):
|
||||
Always return a value greater than input value. Set _M_next_resize to
|
||||
max value when reaching highest prime number.
|
||||
* src/shared/hashtable-aux.cc (__prime_list): Add comment about sentinel
|
||||
being now useless.
|
||||
* testsuite/23_containers/unordered_set/hash_policy/71181.cc: New.
|
||||
* testsuite/23_containers/unordered_set/hash_policy/power2_rehash.cc
|
||||
(test02): New.
|
||||
* testsuite/23_containers/unordered_set/hash_policy/prime_rehash.cc: New.
|
||||
* testsuite/23_containers/unordered_set/hash_policy/rehash.cc:
|
||||
Fix indentation.
|
||||
|
||||
2016-06-17 Jonathan Wakely <jwakely@redhat.com>
|
||||
|
||||
PR libstdc++/71545
|
||||
|
||||
@ -420,8 +420,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
||||
_Prime_rehash_policy::
|
||||
_M_next_bkt(std::size_t __n) const
|
||||
{
|
||||
const unsigned long* __p = std::lower_bound(__prime_list, __prime_list
|
||||
+ _S_n_primes, __n);
|
||||
// Don't include the last prime in the search, so that anything
|
||||
// higher than the second-to-last prime returns a past-the-end
|
||||
// iterator that can be dereferenced to get the last prime.
|
||||
const unsigned long* __p
|
||||
= std::lower_bound(__prime_list, __prime_list + _S_n_primes - 1, __n);
|
||||
_M_next_resize =
|
||||
static_cast<std::size_t>(__builtin_ceil(*__p * _M_max_load_factor));
|
||||
return *__p;
|
||||
@ -434,11 +437,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
||||
_M_bkt_for_elements(std::size_t __n) const
|
||||
{
|
||||
const float __min_bkts = __n / _M_max_load_factor;
|
||||
const unsigned long* __p = std::lower_bound(__prime_list, __prime_list
|
||||
+ _S_n_primes, __min_bkts);
|
||||
_M_next_resize =
|
||||
static_cast<std::size_t>(__builtin_ceil(*__p * _M_max_load_factor));
|
||||
return *__p;
|
||||
return _M_next_bkt(__builtin_ceil(__min_bkts));
|
||||
}
|
||||
|
||||
// Finds the smallest prime p such that alpha p > __n_elt + __n_ins.
|
||||
@ -462,12 +461,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
||||
if (__min_bkts > __n_bkt)
|
||||
{
|
||||
__min_bkts = std::max(__min_bkts, _M_growth_factor * __n_bkt);
|
||||
const unsigned long* __p =
|
||||
std::lower_bound(__prime_list, __prime_list + _S_n_primes,
|
||||
__min_bkts);
|
||||
_M_next_resize = static_cast<std::size_t>
|
||||
(__builtin_ceil(*__p * _M_max_load_factor));
|
||||
return std::make_pair(true, *__p);
|
||||
return std::make_pair(true,
|
||||
_M_next_bkt(__builtin_ceil(__min_bkts)));
|
||||
}
|
||||
else
|
||||
{
|
||||
|
||||
@ -46,22 +46,38 @@ namespace __detail
|
||||
{
|
||||
// Optimize lookups involving the first elements of __prime_list.
|
||||
// (useful to speed-up, eg, constructors)
|
||||
static const unsigned char __fast_bkt[12]
|
||||
= { 2, 2, 2, 3, 5, 5, 7, 7, 11, 11, 11, 11 };
|
||||
static const unsigned char __fast_bkt[13]
|
||||
= { 2, 2, 3, 5, 5, 7, 7, 11, 11, 11, 11, 13, 13 };
|
||||
|
||||
if (__n <= 11)
|
||||
if (__n <= 12)
|
||||
{
|
||||
_M_next_resize =
|
||||
__builtin_ceil(__fast_bkt[__n] * (long double)_M_max_load_factor);
|
||||
return __fast_bkt[__n];
|
||||
}
|
||||
|
||||
// Number of primes (without sentinel).
|
||||
constexpr auto __n_primes
|
||||
= sizeof(__prime_list) / sizeof(unsigned long) - 1;
|
||||
|
||||
// Don't include the last prime in the search, so that anything
|
||||
// higher than the second-to-last prime returns a past-the-end
|
||||
// iterator that can be dereferenced to get the last prime.
|
||||
constexpr auto __last_prime = __prime_list + __n_primes - 1;
|
||||
|
||||
// Look for 'n + 1' to make sure returned value will be greater than n.
|
||||
const unsigned long* __next_bkt =
|
||||
std::lower_bound(__prime_list + 5, __prime_list + __n_primes, __n);
|
||||
_M_next_resize =
|
||||
__builtin_ceil(*__next_bkt * (long double)_M_max_load_factor);
|
||||
std::lower_bound(__prime_list + 6, __last_prime, __n + 1);
|
||||
|
||||
if (__next_bkt == __last_prime)
|
||||
// Set next resize to the max value so that we never try to rehash again
|
||||
// as we already reach the biggest possible bucket number.
|
||||
// Note that it might result in max_load_factor not being respected.
|
||||
_M_next_resize = std::size_t(-1);
|
||||
else
|
||||
_M_next_resize =
|
||||
__builtin_ceil(*__next_bkt * (long double)_M_max_load_factor);
|
||||
|
||||
return *__next_bkt;
|
||||
}
|
||||
|
||||
|
||||
@ -25,6 +25,7 @@
|
||||
namespace __detail
|
||||
{
|
||||
_GLIBCXX_BEGIN_NAMESPACE_VERSION
|
||||
// The sentinel value is kept only for abi backward compatibility.
|
||||
extern const unsigned long __prime_list[] = // 256 + 1 or 256 + 48 + 1
|
||||
{
|
||||
2ul, 3ul, 5ul, 7ul, 11ul, 13ul, 17ul, 19ul, 23ul, 29ul, 31ul,
|
||||
|
||||
@ -0,0 +1,63 @@
|
||||
// Copyright (C) 2016 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++11" }
|
||||
|
||||
#include <unordered_set>
|
||||
|
||||
#include <testsuite_hooks.h>
|
||||
|
||||
template<typename _USet>
|
||||
void test(int threshold)
|
||||
{
|
||||
bool test __attribute__((unused)) = true;
|
||||
_USet us;
|
||||
auto nb_reserved = us.bucket_count();
|
||||
us.reserve(nb_reserved);
|
||||
auto bkts = us.bucket_count();
|
||||
for (int i = 0; i != threshold; ++i)
|
||||
{
|
||||
if (i == nb_reserved)
|
||||
{
|
||||
nb_reserved = bkts;
|
||||
us.reserve(nb_reserved);
|
||||
bkts = us.bucket_count();
|
||||
}
|
||||
|
||||
us.insert(i);
|
||||
|
||||
VERIFY( us.bucket_count() == bkts );
|
||||
}
|
||||
}
|
||||
|
||||
template<typename _Value>
|
||||
using unordered_set_power2_rehash =
|
||||
std::_Hashtable<_Value, _Value, std::allocator<_Value>,
|
||||
std::__detail::_Identity,
|
||||
std::equal_to<_Value>,
|
||||
std::hash<_Value>,
|
||||
std::__detail::_Mask_range_hashing,
|
||||
std::__detail::_Default_ranged_hash,
|
||||
std::__detail::_Power2_rehash_policy,
|
||||
std::__detail::_Hashtable_traits<false, true, true>>;
|
||||
|
||||
int main()
|
||||
{
|
||||
test<std::unordered_set<int>>(150);
|
||||
test<unordered_set_power2_rehash<int>>(150);
|
||||
return 0;
|
||||
}
|
||||
@ -17,6 +17,7 @@
|
||||
//
|
||||
// { dg-options "-std=gnu++11" }
|
||||
|
||||
#include <limits>
|
||||
#include <unordered_set>
|
||||
|
||||
#include <testsuite_hooks.h>
|
||||
@ -35,8 +36,32 @@ void test01()
|
||||
== (std::size_t(1) << (sizeof(std::size_t) * 8 - 1)) );
|
||||
}
|
||||
|
||||
void test02()
|
||||
{
|
||||
bool test __attribute__((unused)) = true;
|
||||
|
||||
std::__detail::_Power2_rehash_policy policy;
|
||||
|
||||
for (std::size_t i = 1;;)
|
||||
{
|
||||
auto nxt = policy._M_next_bkt(i);
|
||||
|
||||
if (nxt == i)
|
||||
{
|
||||
// Equals only when reaching max.
|
||||
constexpr auto mx = std::numeric_limits<std::size_t>::max();
|
||||
VERIFY( nxt == policy._M_next_bkt(mx) );
|
||||
break;
|
||||
}
|
||||
|
||||
VERIFY( nxt > i );
|
||||
i = nxt;
|
||||
}
|
||||
}
|
||||
|
||||
int main()
|
||||
{
|
||||
test01();
|
||||
test02();
|
||||
return 0;
|
||||
}
|
||||
|
||||
@ -0,0 +1,52 @@
|
||||
// Copyright (C) 2016 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++11" }
|
||||
|
||||
#include <limits>
|
||||
#include <unordered_set>
|
||||
|
||||
#include <testsuite_hooks.h>
|
||||
|
||||
void test01()
|
||||
{
|
||||
bool test __attribute__((unused)) = true;
|
||||
|
||||
std::__detail::_Prime_rehash_policy policy;
|
||||
|
||||
for (std::size_t i = 1;;)
|
||||
{
|
||||
auto nxt = policy._M_next_bkt(i);
|
||||
|
||||
if (nxt == i)
|
||||
{
|
||||
// Equals only when reaching max.
|
||||
constexpr auto mx = std::numeric_limits<std::size_t>::max() - 1;
|
||||
VERIFY( nxt == policy._M_next_bkt(mx) );
|
||||
break;
|
||||
}
|
||||
|
||||
VERIFY( nxt > i );
|
||||
i = nxt;
|
||||
}
|
||||
}
|
||||
|
||||
int main()
|
||||
{
|
||||
test01();
|
||||
return 0;
|
||||
}
|
||||
@ -22,40 +22,40 @@
|
||||
#include <testsuite_hooks.h>
|
||||
|
||||
template<typename _USet>
|
||||
void test()
|
||||
{
|
||||
bool test __attribute__((unused)) = true;
|
||||
_USet us;
|
||||
typedef typename _USet::size_type size_type;
|
||||
bool rehashed = false;
|
||||
for (int i = 0; i != 100000; ++i)
|
||||
void test()
|
||||
{
|
||||
size_type bkt_count = us.bucket_count();
|
||||
us.insert(i);
|
||||
if (bkt_count != us.bucket_count())
|
||||
bool test __attribute__((unused)) = true;
|
||||
_USet us;
|
||||
typedef typename _USet::size_type size_type;
|
||||
bool rehashed = false;
|
||||
for (int i = 0; i != 100000; ++i)
|
||||
{
|
||||
// Container has been rehashed, lets check that it won't be rehash again
|
||||
// if we remove and restore the last 2 inserted elements:
|
||||
rehashed = true;
|
||||
bkt_count = us.bucket_count();
|
||||
VERIFY( us.erase(i) == 1 );
|
||||
VERIFY( bkt_count == us.bucket_count() );
|
||||
if (i > 0)
|
||||
size_type bkt_count = us.bucket_count();
|
||||
us.insert(i);
|
||||
if (bkt_count != us.bucket_count())
|
||||
{
|
||||
VERIFY( us.erase(i - 1) == 1 );
|
||||
// Container has been rehashed, lets check that it won't be rehash
|
||||
// again if we remove and restore the last 2 inserted elements:
|
||||
rehashed = true;
|
||||
bkt_count = us.bucket_count();
|
||||
VERIFY( us.erase(i) == 1 );
|
||||
VERIFY( bkt_count == us.bucket_count() );
|
||||
if (i > 0)
|
||||
{
|
||||
VERIFY( us.erase(i - 1) == 1 );
|
||||
VERIFY( bkt_count == us.bucket_count() );
|
||||
|
||||
VERIFY( us.insert(i - 1).second );
|
||||
VERIFY( us.insert(i - 1).second );
|
||||
VERIFY( bkt_count == us.bucket_count() );
|
||||
}
|
||||
VERIFY( us.insert(i).second );
|
||||
VERIFY( bkt_count == us.bucket_count() );
|
||||
}
|
||||
VERIFY( us.insert(i).second );
|
||||
VERIFY( bkt_count == us.bucket_count() );
|
||||
}
|
||||
}
|
||||
|
||||
// At lest we check a rehash once:
|
||||
VERIFY( rehashed );
|
||||
}
|
||||
// At lest we check a rehash once:
|
||||
VERIFY( rehashed );
|
||||
}
|
||||
|
||||
template<typename _Value>
|
||||
using unordered_set_power2_rehash =
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user