Those methods are making a double lookup in case of insertion, they can
perform only one.
PR libstdc++/95079
* include/bits/hashtable_policy.h (_Insert_base<>::try_emplace): New.
* include/bits/unordered_map.h (unordered_map<>::try_emplace): Adapt.
(unordered_map<>::insert_or_assign): Adapt.
Move std::is_permutation algorithm with associated helpers to stl_algobase.h
to remove stl_algo.h include from hashtable_policy.h and so reduce preprocess
size of unordered_map and unordered_set headers.
* include/bits/stl_algo.h
(__find_if, __count_if, __is_permutation, std::is_permutation): Move...
* include/bits/stl_algobase.h: ...here.
* include/bits/hashtable_policy.h: Remove <bits/stl_algo.h> include.
Implement this change for C++20 that was just approved in Prague.
P1956R1 On the names of low-level bit manipulation functions
* include/bits/hashtable_policy.h: Update comment.
* include/std/bit (__ispow2, __ceil2, __floor2, __log2p1): Rename.
(ispow2, ceil2, floor2, log2p1): Likewise.
(__cpp_lib_int_pow2): Add feature test macro.
* include/std/charconv (__to_chars_len_2): Adjust use of __log2p1.
* include/std/memory (assume_aligned): Adjust use of ispow2.
* include/std/version (__cpp_lib_int_pow2): Add.
* libsupc++/new_opa.cc: Adjust use of __ispow2.
* src/c++17/memory_resource.cc: Likewise, and for __ceil2 and __log2p1.
* testsuite/17_intro/freestanding.cc: Adjust use of ispow2.
* testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: Rename to ...
* testsuite/26_numerics/bit/bit.pow.two/bit_ceil.cc: ... here.
* testsuite/26_numerics/bit/bit.pow.two/ceil2_neg.cc: Rename to ...
* testsuite/26_numerics/bit/bit.pow.two/bit_ceil_neg.cc: ... here.
* testsuite/26_numerics/bit/bit.pow.two/floor2.cc: Rename to ...
* testsuite/26_numerics/bit/bit.pow.two/bit_floor.cc: ... here.
* testsuite/26_numerics/bit/bit.pow.two/log2p1.cc: Rename to ...
* testsuite/26_numerics/bit/bit.pow.two/bit_width.cc: ... here.
* testsuite/26_numerics/bit/bit.pow.two/ispow2.cc: Rename to ...
* testsuite/26_numerics/bit/bit.pow.two/has_single_bit.cc: ... here.
Avoid comparing elements with operator== multiple times by replacing
uses of find and equal_range with equivalent inlined code that uses
operator== instead of the container's equality comparison predicate.
This is valid because the standard requires that operator== is a
refinement of the equality predicate.
Also replace the _S_is_permutation function with std::is_permutation,
which wasn't yet implemented when this code was first written.
PR libstdc++/91263
* include/bits/hashtable.h (_Hashtable<>): Make _Equality<> friend.
* include/bits/hashtable_policy.h: Include <bits/stl_algo.h>.
(_Equality_base): Remove.
(_Equality<>::_M_equal): Review implementation. Use
std::is_permutation.
* testsuite/23_containers/unordered_multiset/operators/1.cc
(Hash, Equal, test02, test03): New.
* testsuite/23_containers/unordered_set/operators/1.cc
(Hash, Equal, test02, test03): New.
Introduce an RAII type to manage nodes in unordered containers while
they are being inserted. If the caller always owns a node until it is
inserted, then the insertion functions don't need to deallocate on
failure. This allows a FIXME in the node re-insertion API to be removed.
Also change extract(const key_type&) to not call extract(const_iterator)
anymore. This avoids looping through the bucket nodes again to find the
node before the one being extracted.
2019-06-17 François Dumont <fdumont@gcc.gnu.org>
Jonathan Wakely <jwakely@redhat.com>
* include/bits/hashtable.h (struct _Hashtable::_Scoped_node): New type.
(_Hashtable::_M_insert_unique_node): Add key_type parameter. Don't
deallocate node if insertion fails.
(_Hashtable::_M_insert_multi_node): Likewise.
(_Hashtable::_M_reinsert_node): Pass additional key argument.
(_Hashtable::_M_reinsert_node_multi): Likewise. Remove FIXME.
(_Hashtable::_M_extract_node(size_t, __node_base*)): New function.
(_Hashtable::extract(const_iterator)): Use _M_extract_node.
(_Hashtable::extract(const _Key&)): Likewise.
(_Hashtable::_M_merge_unique): Pass additional key argument.
(_Hashtable::_M_emplace<Args>(true_type, Args&&...)): Likewise. Use
_Scoped_node.
(_Hashtable::_M_insert): Likewise.
* include/bits/hashtable_policy.h (_Map_base::operator[]): Likewise.
(_Hashtable_alloc): Add comments to functions with misleading names.
Co-Authored-By: Jonathan Wakely <jwakely@redhat.com>
From-SVN: r272381
This is another attempt to reduce how often the assertions are
evaluated, so that code which doesn't try to use the function objects
doesn't need them to be invocable.
For _Rb_tree we access the _M_key_compare object directly, so can't put
the assertions in an accessor function for it. However, every invocation
of _M_key_compare is accompanied by a use of _S_key, so the assertions
can be put in there. For _Hashtable there are member functions that are
consistently used to obtain a hash code or test for equality, so the
assertions can go in those members.
PR libstdc++/85965
* include/bits/hashtable.h (_Hashtable::~_Hashtable()): Remove static
assertions from the destructor.
* include/bits/hashtable_policy.h (_Hash_code_base::_M_hash_code):
Move static_assert for hash function to here.
(_Hash_table_base::_M_equals): Move static_assert for equality
predicate to here.
* include/bits/stl_tree.h (_Rb_tree::_S_value(_Const_Link_type)):
Remove.
(_Rb_tree::_S_key(_Const_Link_type)): Move assertions here. Access
the value directly instead of calling _S_value.
(_Rb_tree::_S_value(_Const_Base_ptr)): Remove.
(_Rb_tree::_S_key(_Const_Base_ptr)): Do downcast and forward to
_S_key(_Const_Link_type).
* testsuite/23_containers/set/85965.cc: Check construction,
destruction, assignment and size() do not trigger the assertions.
* testsuite/23_containers/unordered_set/85965.cc: Likewise.
* testsuite/23_containers/map/48101_neg.cc: Call find and adjust
expected errors.
* testsuite/23_containers/multimap/48101_neg.cc: Likewise.
* testsuite/23_containers/multiset/48101_neg.cc: Likewise.
* testsuite/23_containers/set/48101_neg.cc: Likewise.
* testsuite/23_containers/unordered_map/48101_neg.cc: Likewise.
* testsuite/23_containers/unordered_multimap/48101_neg.cc: Likewise.
* testsuite/23_containers/unordered_multiset/48101_neg.cc: Likewise.
* testsuite/23_containers/unordered_set/48101_neg.cc: Likewise.
From-SVN: r271323
By defining the new helper inside _Hashtable_base it doesn't need all
the template parameters to be provided, and by making it only
responsible for checking a possibly-cached hash code it only has to do
one thing. The caller can use the equality predicate itself instead of
duplicating that in the helper template.
* include/bits/hashtable_policy.h (_Equal_helper): Remove.
(_Hashtable_base::_Equal_hash_code): Define new class template.
(_Hashtable_base::_M_equals): Use _Equal_hash_code instead of
_Equal_helper.
From-SVN: r271291
* include/bits/hashtable_policy.h (_Hashtable_ebo_helper::_S_get):
Replace with _M_get non-static member function.
(_Hashtable_ebo_helper::_S_cget): Replace with _M_cget non-static
member function.
(_Hash_code_base, _Local_iterator_base, _Hashtable_base):
(_Hashtable_alloc): Adjust to use non-static members of EBO helper.
From-SVN: r271290
The const accessors are OK (and arguably more correct) for most callers
to use. The _M_swap functions that use the non-const overloads can just
directly use the _S_get members of the EBO helpers.
* include/bits/hashtable_policy.h (_Hash_code_base::_M_swap): Use
_S_get accessors for members in EBO helpers.
(_Hash_code_base::_M_extract(), _Hash_code_base::_M_ranged_hash())
(_Hash_code_base::_M_h1(), _Hash_code_base::_M_h2()): Remove non-const
overloads.
(_Hashtable_base::_M_swap): Use _S_get accessors for members in EBO
helpers.
(_Hashtable_base::_M_eq()): Remove non-const overload.
From-SVN: r271286
2019-05-04 François Dumont <fdumont@gcc.gnu.org>
* include/bits/hashtable.h (_Hashtable<>::rehash): Review comment.
* include/bits/hashtable_policy.h
(_Prime_rehash_policy::_M_bkt_for_elements): Use __builtin_ceill.
(_Power2_rehash_policy::_M_bkt_for_elements): Likewise.
(_Power2_rehash_policy::_M_next_bkt): Enforce returning a result not
smaller than input value rather than always greater. Preserve
_M_next_resize if called with 0 input. Use __builtin_floorl.
(_Power2_rehash_policy::_M_need_rehash): Rehash only if number of
elements + number of insertions is greater than _M_next_resize. Start
with 11 buckets if not told otherwise. Use __builtin_floorl.
(_Rehash_base<>::reserve): Use rehash policy _M_bkt_for_elements.
* src/c++11/hashtable_c++0x.cc (_Prime_rehash_policy::_M_next_bkt):
Preserve _M_next_resize if called with 0 input. Use __builtin_floorl.
(_Prime_rehash_policy::_M_need_rehash): Start with 11 buckets if not
told otherwise. Use __builtin_floorl.
* testsuite/23_containers/unordered_set/hash_policy/71181.cc: Adapt test
to also validate _Power2_rehash_policy.
* testsuite/23_containers/unordered_set/hash_policy/power2_rehash.cc:
Adapt.
From-SVN: r270868
For values where the result cannot be represented the shift width would
be equal to the width of the type, which is undefined. Perform two
well-defined shifts instead of one possible undefined shift.
* include/bits/hashtable_policy.h (__clp2): Fix calculation for LLP64
targets where sizeof(size_t) > sizeof(long). Avoid undefined shifts
of the number of bits in the type.
* include/std/bit (__ceil2): Avoid undefined shifts.
* testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: Test values with
the most signifiant bit set.
From-SVN: r263986
std::__detail::__clp2 used uint_fast32_t and uint_fast64_t without
checking _GLIBCXX_USE_C99_STDINT_TR1 which was a potential bug. A
simpler implementation based on the new std::__ceil2 code performs
better and doesn't depend on <stdint.h> types.
std::align and other C++11 functions in <memory> where unnecessarily
missing when _GLIBCXX_USE_C99_STDINT_TR1 was not defined.
* include/bits/hashtable_policy.h (__detail::__clp2): Use faster
implementation that doesn't depend on <stdint.h> types.
* include/std/memory (align) [!_GLIBCXX_USE_C99_STDINT_TR1]: Use
std::size_t when std::uintptr_t is not usable.
[!_GLIBCXX_USE_C99_STDINT_TR1] (pointer_safety, declare_reachable)
(undeclare_reachable, declare_no_pointers, undeclare_no_pointers):
Define independent of _GLIBCXX_USE_C99_STDINT_TR1.
From-SVN: r263003
* include/bits/hashtable_policy.h: Include <tuple>.
* include/std/unordered_map: Only include <bits/stl_pair.h> instead
of <utility> and <tuple>.
* include/std/unordered_set: Likewise.
From-SVN: r254223
* include/bits/hashtable_policy.h (_ReuseOrAllocNode): Remove
__value_alloc_type and __value_alloc_traits typedefs.
(_ReuseOrAllocNode::operator()): Call construct and destroy on the
node allocator.
(_Hashtable_alloc): Simplify __value_alloc_traits typedef.
(_Hashtable_alloc<_NodeAlloc>::_M_allocate_node(_Args&&...)): Call
construct on the node allocator.
(_Hashtable_alloc<_NodeAlloc>::_M_deallocate_node(__node_type*)): Call
destroy on the node allocator.
From-SVN: r251187
2015-04-30 François Dumont <fdumont@gcc.gnu.org>
* include/bits/hashtable_policy.h (_Prime_rehash_policy::_S_n_primes):
Delete.
* src/c++11/hashtable_c++0x.cc (_Prime_rehash_policy::_M_next_bkt):
Remove usage of latter and compute size of the prime numbers array
locally.
From-SVN: r222611
PR libstdc++/56267
* include/bits/hashtable_policy.h (_Hash_code_base<... false>): Grant
friendship to _Local_iterator_base<..., false>.
(_Local_iterator_base): Give protected access to all existing members.
(_Local_iterator_base::_M_curr()): New public accessor.
(_Local_iterator_base::_M_get_bucket()): New public accessor.
(_Local_iterator_base<..., false>::_M_init()): New function to manage
the lifetime of the _Hash_code_base explicitly.
(_Local_iterator_base<..., false>::_M_destroy()): Likewise.
(_Local_iterator_base<..., false>): Define copy constructor and copy
assignment operator that use new functions to manage _Hash_code_base.
(operator==(const _Local_iterator_base&, const _Local_iterator_base&),
operator==(const _Local_iterator_base&, const _Local_iterator_base&)):
Use public API for _Local_iterator_base.
* include/debug/safe_local_iterator.h (_Safe_local_iterator): Likewise.
* include/debug/unordered_map (__debug::unordered_map::erase(),
__debug::unordered_multimap::erase()): Likewise.
* include/debug/unordered_set (__debug::unordered_set::erase(),
__debug::unordered_multiset::erase()): Likewise.
* testsuite/23_containers/unordered_set/56267-2.cc: New test.
From-SVN: r206834
2014-01-15 François Dumont <fdumont@gcc.gnu.org>
* include/bits/hashtable_policy.h: Fix some long lines.
* include/bits/hashtable.h (__hash_code_base_access): Define and
use it to check its _M_bucket_index noexcept qualification. Use
also in place of...
(__access_protected_ctor): ...this.
* testsuite/23_containers/unordered_set/instantiation_neg.cc:
Adapt line number.
* testsuite/23_containers/unordered_set/
not_default_constructible_hash_neg.cc: Likewise.
From-SVN: r206632
2013-07-05 François Dumont <fdumont@gcc.gnu.org>
* include/bits/hashtable_policy.h (_ReuseOrAllocNode): Use forward
pattern.
(_MoveReuseOrAllocNode): Remove.
(_Insert_base): Take a functor defining how the node is generated.
* include/bits/hashtable.h: Adapt.
(operator=(initializer_list<value_type>)): Reuse node if any.
* testsuite/23_containers/unordered_set/instantiation_neg.cc:
Adjust dg-error line number.
* testsuite/23_containers/unordered_set/
not_default_constructible_hash_neg.cc: Likewise.
From-SVN: r200724
