From 1bc5aee63eb72b341f506ad058502cd0361f0d10 Mon Sep 17 00:00:00 2001 From: Ben Cheng Date: Tue, 25 Mar 2014 22:37:19 -0700 Subject: Initial checkin of GCC 4.9.0 from trunk (r208799). Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba --- .../libstdc++-v3/include/tr1/hashtable_policy.h | 783 +++++++++++++++++++++ 1 file changed, 783 insertions(+) create mode 100644 gcc-4.9/libstdc++-v3/include/tr1/hashtable_policy.h (limited to 'gcc-4.9/libstdc++-v3/include/tr1/hashtable_policy.h') diff --git a/gcc-4.9/libstdc++-v3/include/tr1/hashtable_policy.h b/gcc-4.9/libstdc++-v3/include/tr1/hashtable_policy.h new file mode 100644 index 0000000..7541f6e --- /dev/null +++ b/gcc-4.9/libstdc++-v3/include/tr1/hashtable_policy.h @@ -0,0 +1,783 @@ +// Internal policy header for TR1 unordered_set and unordered_map -*- C++ -*- + +// Copyright (C) 2010-2014 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. + +// Under Section 7 of GPL version 3, you are granted additional +// permissions described in the GCC Runtime Library Exception, version +// 3.1, as published by the Free Software Foundation. + +// You should have received a copy of the GNU General Public License and +// a copy of the GCC Runtime Library Exception along with this program; +// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see +// . + +/** @file tr1/hashtable_policy.h + * This is an internal header file, included by other library headers. + * Do not attempt to use it directly. + * @headername{tr1/unordered_map, tr1/unordered_set} + */ + +namespace std _GLIBCXX_VISIBILITY(default) +{ +namespace tr1 +{ +namespace __detail +{ +_GLIBCXX_BEGIN_NAMESPACE_VERSION + + // Helper function: return distance(first, last) for forward + // iterators, or 0 for input iterators. + template + inline typename std::iterator_traits<_Iterator>::difference_type + __distance_fw(_Iterator __first, _Iterator __last, + std::input_iterator_tag) + { return 0; } + + template + inline typename std::iterator_traits<_Iterator>::difference_type + __distance_fw(_Iterator __first, _Iterator __last, + std::forward_iterator_tag) + { return std::distance(__first, __last); } + + template + inline typename std::iterator_traits<_Iterator>::difference_type + __distance_fw(_Iterator __first, _Iterator __last) + { + typedef typename std::iterator_traits<_Iterator>::iterator_category _Tag; + return __distance_fw(__first, __last, _Tag()); + } + + // Auxiliary types used for all instantiations of _Hashtable: nodes + // and iterators. + + // Nodes, used to wrap elements stored in the hash table. A policy + // template parameter of class template _Hashtable controls whether + // nodes also store a hash code. In some cases (e.g. strings) this + // may be a performance win. + template + struct _Hash_node; + + template + struct _Hash_node<_Value, true> + { + _Value _M_v; + std::size_t _M_hash_code; + _Hash_node* _M_next; + }; + + template + struct _Hash_node<_Value, false> + { + _Value _M_v; + _Hash_node* _M_next; + }; + + // Local iterators, used to iterate within a bucket but not between + // buckets. + template + struct _Node_iterator_base + { + _Node_iterator_base(_Hash_node<_Value, __cache>* __p) + : _M_cur(__p) { } + + void + _M_incr() + { _M_cur = _M_cur->_M_next; } + + _Hash_node<_Value, __cache>* _M_cur; + }; + + template + inline bool + operator==(const _Node_iterator_base<_Value, __cache>& __x, + const _Node_iterator_base<_Value, __cache>& __y) + { return __x._M_cur == __y._M_cur; } + + template + inline bool + operator!=(const _Node_iterator_base<_Value, __cache>& __x, + const _Node_iterator_base<_Value, __cache>& __y) + { return __x._M_cur != __y._M_cur; } + + template + struct _Node_iterator + : public _Node_iterator_base<_Value, __cache> + { + typedef _Value value_type; + typedef typename + __gnu_cxx::__conditional_type<__constant_iterators, + const _Value*, _Value*>::__type + pointer; + typedef typename + __gnu_cxx::__conditional_type<__constant_iterators, + const _Value&, _Value&>::__type + reference; + typedef std::ptrdiff_t difference_type; + typedef std::forward_iterator_tag iterator_category; + + _Node_iterator() + : _Node_iterator_base<_Value, __cache>(0) { } + + explicit + _Node_iterator(_Hash_node<_Value, __cache>* __p) + : _Node_iterator_base<_Value, __cache>(__p) { } + + reference + operator*() const + { return this->_M_cur->_M_v; } + + pointer + operator->() const + { return std::__addressof(this->_M_cur->_M_v); } + + _Node_iterator& + operator++() + { + this->_M_incr(); + return *this; + } + + _Node_iterator + operator++(int) + { + _Node_iterator __tmp(*this); + this->_M_incr(); + return __tmp; + } + }; + + template + struct _Node_const_iterator + : public _Node_iterator_base<_Value, __cache> + { + typedef _Value value_type; + typedef const _Value* pointer; + typedef const _Value& reference; + typedef std::ptrdiff_t difference_type; + typedef std::forward_iterator_tag iterator_category; + + _Node_const_iterator() + : _Node_iterator_base<_Value, __cache>(0) { } + + explicit + _Node_const_iterator(_Hash_node<_Value, __cache>* __p) + : _Node_iterator_base<_Value, __cache>(__p) { } + + _Node_const_iterator(const _Node_iterator<_Value, __constant_iterators, + __cache>& __x) + : _Node_iterator_base<_Value, __cache>(__x._M_cur) { } + + reference + operator*() const + { return this->_M_cur->_M_v; } + + pointer + operator->() const + { return std::__addressof(this->_M_cur->_M_v); } + + _Node_const_iterator& + operator++() + { + this->_M_incr(); + return *this; + } + + _Node_const_iterator + operator++(int) + { + _Node_const_iterator __tmp(*this); + this->_M_incr(); + return __tmp; + } + }; + + template + struct _Hashtable_iterator_base + { + _Hashtable_iterator_base(_Hash_node<_Value, __cache>* __node, + _Hash_node<_Value, __cache>** __bucket) + : _M_cur_node(__node), _M_cur_bucket(__bucket) { } + + void + _M_incr() + { + _M_cur_node = _M_cur_node->_M_next; + if (!_M_cur_node) + _M_incr_bucket(); + } + + void + _M_incr_bucket(); + + _Hash_node<_Value, __cache>* _M_cur_node; + _Hash_node<_Value, __cache>** _M_cur_bucket; + }; + + // Global iterators, used for arbitrary iteration within a hash + // table. Larger and more expensive than local iterators. + template + void + _Hashtable_iterator_base<_Value, __cache>:: + _M_incr_bucket() + { + ++_M_cur_bucket; + + // This loop requires the bucket array to have a non-null sentinel. + while (!*_M_cur_bucket) + ++_M_cur_bucket; + _M_cur_node = *_M_cur_bucket; + } + + template + inline bool + operator==(const _Hashtable_iterator_base<_Value, __cache>& __x, + const _Hashtable_iterator_base<_Value, __cache>& __y) + { return __x._M_cur_node == __y._M_cur_node; } + + template + inline bool + operator!=(const _Hashtable_iterator_base<_Value, __cache>& __x, + const _Hashtable_iterator_base<_Value, __cache>& __y) + { return __x._M_cur_node != __y._M_cur_node; } + + template + struct _Hashtable_iterator + : public _Hashtable_iterator_base<_Value, __cache> + { + typedef _Value value_type; + typedef typename + __gnu_cxx::__conditional_type<__constant_iterators, + const _Value*, _Value*>::__type + pointer; + typedef typename + __gnu_cxx::__conditional_type<__constant_iterators, + const _Value&, _Value&>::__type + reference; + typedef std::ptrdiff_t difference_type; + typedef std::forward_iterator_tag iterator_category; + + _Hashtable_iterator() + : _Hashtable_iterator_base<_Value, __cache>(0, 0) { } + + _Hashtable_iterator(_Hash_node<_Value, __cache>* __p, + _Hash_node<_Value, __cache>** __b) + : _Hashtable_iterator_base<_Value, __cache>(__p, __b) { } + + explicit + _Hashtable_iterator(_Hash_node<_Value, __cache>** __b) + : _Hashtable_iterator_base<_Value, __cache>(*__b, __b) { } + + reference + operator*() const + { return this->_M_cur_node->_M_v; } + + pointer + operator->() const + { return std::__addressof(this->_M_cur_node->_M_v); } + + _Hashtable_iterator& + operator++() + { + this->_M_incr(); + return *this; + } + + _Hashtable_iterator + operator++(int) + { + _Hashtable_iterator __tmp(*this); + this->_M_incr(); + return __tmp; + } + }; + + template + struct _Hashtable_const_iterator + : public _Hashtable_iterator_base<_Value, __cache> + { + typedef _Value value_type; + typedef const _Value* pointer; + typedef const _Value& reference; + typedef std::ptrdiff_t difference_type; + typedef std::forward_iterator_tag iterator_category; + + _Hashtable_const_iterator() + : _Hashtable_iterator_base<_Value, __cache>(0, 0) { } + + _Hashtable_const_iterator(_Hash_node<_Value, __cache>* __p, + _Hash_node<_Value, __cache>** __b) + : _Hashtable_iterator_base<_Value, __cache>(__p, __b) { } + + explicit + _Hashtable_const_iterator(_Hash_node<_Value, __cache>** __b) + : _Hashtable_iterator_base<_Value, __cache>(*__b, __b) { } + + _Hashtable_const_iterator(const _Hashtable_iterator<_Value, + __constant_iterators, __cache>& __x) + : _Hashtable_iterator_base<_Value, __cache>(__x._M_cur_node, + __x._M_cur_bucket) { } + + reference + operator*() const + { return this->_M_cur_node->_M_v; } + + pointer + operator->() const + { return std::__addressof(this->_M_cur_node->_M_v); } + + _Hashtable_const_iterator& + operator++() + { + this->_M_incr(); + return *this; + } + + _Hashtable_const_iterator + operator++(int) + { + _Hashtable_const_iterator __tmp(*this); + this->_M_incr(); + return __tmp; + } + }; + + + // Many of class template _Hashtable's template parameters are policy + // classes. These are defaults for the policies. + + // Default range hashing function: use division to fold a large number + // into the range [0, N). + struct _Mod_range_hashing + { + typedef std::size_t first_argument_type; + typedef std::size_t second_argument_type; + typedef std::size_t result_type; + + result_type + operator()(first_argument_type __num, second_argument_type __den) const + { return __num % __den; } + }; + + // Default ranged hash function H. In principle it should be a + // function object composed from objects of type H1 and H2 such that + // h(k, N) = h2(h1(k), N), but that would mean making extra copies of + // h1 and h2. So instead we'll just use a tag to tell class template + // hashtable to do that composition. + struct _Default_ranged_hash { }; + + // Default value for rehash policy. Bucket size is (usually) the + // smallest prime that keeps the load factor small enough. + struct _Prime_rehash_policy + { + _Prime_rehash_policy(float __z = 1.0) + : _M_max_load_factor(__z), _M_growth_factor(2.f), _M_next_resize(0) { } + + float + max_load_factor() const + { return _M_max_load_factor; } + + // Return a bucket size no smaller than n. + std::size_t + _M_next_bkt(std::size_t __n) const; + + // Return a bucket count appropriate for n elements + std::size_t + _M_bkt_for_elements(std::size_t __n) const; + + // __n_bkt is current bucket count, __n_elt is current element count, + // and __n_ins is number of elements to be inserted. Do we need to + // increase bucket count? If so, return make_pair(true, n), where n + // is the new bucket count. If not, return make_pair(false, 0). + std::pair + _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt, + std::size_t __n_ins) const; + + enum { _S_n_primes = sizeof(unsigned long) != 8 ? 256 : 256 + 48 }; + + float _M_max_load_factor; + float _M_growth_factor; + mutable std::size_t _M_next_resize; + }; + + extern const unsigned long __prime_list[]; + + // XXX This is a hack. There's no good reason for any of + // _Prime_rehash_policy's member functions to be inline. + + // Return a prime no smaller than n. + inline std::size_t + _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); + _M_next_resize = + static_cast(__builtin_ceil(*__p * _M_max_load_factor)); + return *__p; + } + + // Return the smallest prime p such that alpha p >= n, where alpha + // is the load factor. + inline std::size_t + _Prime_rehash_policy:: + _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(__builtin_ceil(*__p * _M_max_load_factor)); + return *__p; + } + + // Finds the smallest prime p such that alpha p > __n_elt + __n_ins. + // If p > __n_bkt, return make_pair(true, p); otherwise return + // make_pair(false, 0). In principle this isn't very different from + // _M_bkt_for_elements. + + // The only tricky part is that we're caching the element count at + // which we need to rehash, so we don't have to do a floating-point + // multiply for every insertion. + + inline std::pair + _Prime_rehash_policy:: + _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt, + std::size_t __n_ins) const + { + if (__n_elt + __n_ins > _M_next_resize) + { + float __min_bkts = ((float(__n_ins) + float(__n_elt)) + / _M_max_load_factor); + 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 + (__builtin_ceil(*__p * _M_max_load_factor)); + return std::make_pair(true, *__p); + } + else + { + _M_next_resize = static_cast + (__builtin_ceil(__n_bkt * _M_max_load_factor)); + return std::make_pair(false, 0); + } + } + else + return std::make_pair(false, 0); + } + + // Base classes for std::tr1::_Hashtable. We define these base + // classes because in some cases we want to do different things + // depending on the value of a policy class. In some cases the + // policy class affects which member functions and nested typedefs + // are defined; we handle that by specializing base class templates. + // Several of the base class templates need to access other members + // of class template _Hashtable, so we use the "curiously recurring + // template pattern" for them. + + // class template _Map_base. If the hashtable has a value type of the + // form pair and a key extraction policy that returns the + // first part of the pair, the hashtable gets a mapped_type typedef. + // If it satisfies those criteria and also has unique keys, then it + // also gets an operator[]. + template + struct _Map_base { }; + + template + struct _Map_base<_Key, _Pair, std::_Select1st<_Pair>, false, _Hashtable> + { + typedef typename _Pair::second_type mapped_type; + }; + + template + struct _Map_base<_Key, _Pair, std::_Select1st<_Pair>, true, _Hashtable> + { + typedef typename _Pair::second_type mapped_type; + + mapped_type& + operator[](const _Key& __k); + }; + + template + typename _Map_base<_Key, _Pair, std::_Select1st<_Pair>, + true, _Hashtable>::mapped_type& + _Map_base<_Key, _Pair, std::_Select1st<_Pair>, true, _Hashtable>:: + operator[](const _Key& __k) + { + _Hashtable* __h = static_cast<_Hashtable*>(this); + typename _Hashtable::_Hash_code_type __code = __h->_M_hash_code(__k); + std::size_t __n = __h->_M_bucket_index(__k, __code, + __h->_M_bucket_count); + + typename _Hashtable::_Node* __p = + __h->_M_find_node(__h->_M_buckets[__n], __k, __code); + if (!__p) + return __h->_M_insert_bucket(std::make_pair(__k, mapped_type()), + __n, __code)->second; + return (__p->_M_v).second; + } + + // class template _Rehash_base. Give hashtable the max_load_factor + // functions iff the rehash policy is _Prime_rehash_policy. + template + struct _Rehash_base { }; + + template + struct _Rehash_base<_Prime_rehash_policy, _Hashtable> + { + float + max_load_factor() const + { + const _Hashtable* __this = static_cast(this); + return __this->__rehash_policy().max_load_factor(); + } + + void + max_load_factor(float __z) + { + _Hashtable* __this = static_cast<_Hashtable*>(this); + __this->__rehash_policy(_Prime_rehash_policy(__z)); + } + }; + + // Class template _Hash_code_base. Encapsulates two policy issues that + // aren't quite orthogonal. + // (1) the difference between using a ranged hash function and using + // the combination of a hash function and a range-hashing function. + // In the former case we don't have such things as hash codes, so + // we have a dummy type as placeholder. + // (2) Whether or not we cache hash codes. Caching hash codes is + // meaningless if we have a ranged hash function. + // We also put the key extraction and equality comparison function + // objects here, for convenience. + + // Primary template: unused except as a hook for specializations. + template + struct _Hash_code_base; + + // Specialization: ranged hash function, no caching hash codes. H1 + // and H2 are provided but ignored. We define a dummy hash code type. + template + struct _Hash_code_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, + _Hash, false> + { + protected: + _Hash_code_base(const _ExtractKey& __ex, const _Equal& __eq, + const _H1&, const _H2&, const _Hash& __h) + : _M_extract(__ex), _M_eq(__eq), _M_ranged_hash(__h) { } + + typedef void* _Hash_code_type; + + _Hash_code_type + _M_hash_code(const _Key& __key) const + { return 0; } + + std::size_t + _M_bucket_index(const _Key& __k, _Hash_code_type, + std::size_t __n) const + { return _M_ranged_hash(__k, __n); } + + std::size_t + _M_bucket_index(const _Hash_node<_Value, false>* __p, + std::size_t __n) const + { return _M_ranged_hash(_M_extract(__p->_M_v), __n); } + + bool + _M_compare(const _Key& __k, _Hash_code_type, + _Hash_node<_Value, false>* __n) const + { return _M_eq(__k, _M_extract(__n->_M_v)); } + + void + _M_store_code(_Hash_node<_Value, false>*, _Hash_code_type) const + { } + + void + _M_copy_code(_Hash_node<_Value, false>*, + const _Hash_node<_Value, false>*) const + { } + + void + _M_swap(_Hash_code_base& __x) + { + std::swap(_M_extract, __x._M_extract); + std::swap(_M_eq, __x._M_eq); + std::swap(_M_ranged_hash, __x._M_ranged_hash); + } + + protected: + _ExtractKey _M_extract; + _Equal _M_eq; + _Hash _M_ranged_hash; + }; + + + // No specialization for ranged hash function while caching hash codes. + // That combination is meaningless, and trying to do it is an error. + + + // Specialization: ranged hash function, cache hash codes. This + // combination is meaningless, so we provide only a declaration + // and no definition. + template + struct _Hash_code_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, + _Hash, true>; + + // Specialization: hash function and range-hashing function, no + // caching of hash codes. H is provided but ignored. Provides + // typedef and accessor required by TR1. + template + struct _Hash_code_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, + _Default_ranged_hash, false> + { + typedef _H1 hasher; + + hasher + hash_function() const + { return _M_h1; } + + protected: + _Hash_code_base(const _ExtractKey& __ex, const _Equal& __eq, + const _H1& __h1, const _H2& __h2, + const _Default_ranged_hash&) + : _M_extract(__ex), _M_eq(__eq), _M_h1(__h1), _M_h2(__h2) { } + + typedef std::size_t _Hash_code_type; + + _Hash_code_type + _M_hash_code(const _Key& __k) const + { return _M_h1(__k); } + + std::size_t + _M_bucket_index(const _Key&, _Hash_code_type __c, + std::size_t __n) const + { return _M_h2(__c, __n); } + + std::size_t + _M_bucket_index(const _Hash_node<_Value, false>* __p, + std::size_t __n) const + { return _M_h2(_M_h1(_M_extract(__p->_M_v)), __n); } + + bool + _M_compare(const _Key& __k, _Hash_code_type, + _Hash_node<_Value, false>* __n) const + { return _M_eq(__k, _M_extract(__n->_M_v)); } + + void + _M_store_code(_Hash_node<_Value, false>*, _Hash_code_type) const + { } + + void + _M_copy_code(_Hash_node<_Value, false>*, + const _Hash_node<_Value, false>*) const + { } + + void + _M_swap(_Hash_code_base& __x) + { + std::swap(_M_extract, __x._M_extract); + std::swap(_M_eq, __x._M_eq); + std::swap(_M_h1, __x._M_h1); + std::swap(_M_h2, __x._M_h2); + } + + protected: + _ExtractKey _M_extract; + _Equal _M_eq; + _H1 _M_h1; + _H2 _M_h2; + }; + + // Specialization: hash function and range-hashing function, + // caching hash codes. H is provided but ignored. Provides + // typedef and accessor required by TR1. + template + struct _Hash_code_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, + _Default_ranged_hash, true> + { + typedef _H1 hasher; + + hasher + hash_function() const + { return _M_h1; } + + protected: + _Hash_code_base(const _ExtractKey& __ex, const _Equal& __eq, + const _H1& __h1, const _H2& __h2, + const _Default_ranged_hash&) + : _M_extract(__ex), _M_eq(__eq), _M_h1(__h1), _M_h2(__h2) { } + + typedef std::size_t _Hash_code_type; + + _Hash_code_type + _M_hash_code(const _Key& __k) const + { return _M_h1(__k); } + + std::size_t + _M_bucket_index(const _Key&, _Hash_code_type __c, + std::size_t __n) const + { return _M_h2(__c, __n); } + + std::size_t + _M_bucket_index(const _Hash_node<_Value, true>* __p, + std::size_t __n) const + { return _M_h2(__p->_M_hash_code, __n); } + + bool + _M_compare(const _Key& __k, _Hash_code_type __c, + _Hash_node<_Value, true>* __n) const + { return __c == __n->_M_hash_code && _M_eq(__k, _M_extract(__n->_M_v)); } + + void + _M_store_code(_Hash_node<_Value, true>* __n, _Hash_code_type __c) const + { __n->_M_hash_code = __c; } + + void + _M_copy_code(_Hash_node<_Value, true>* __to, + const _Hash_node<_Value, true>* __from) const + { __to->_M_hash_code = __from->_M_hash_code; } + + void + _M_swap(_Hash_code_base& __x) + { + std::swap(_M_extract, __x._M_extract); + std::swap(_M_eq, __x._M_eq); + std::swap(_M_h1, __x._M_h1); + std::swap(_M_h2, __x._M_h2); + } + + protected: + _ExtractKey _M_extract; + _Equal _M_eq; + _H1 _M_h1; + _H2 _M_h2; + }; +_GLIBCXX_END_NAMESPACE_VERSION +} // namespace __detail +} +} -- cgit v1.1