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1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef _LIBCPP___ALGORITHM_STABLE_SORT_H10#define _LIBCPP___ALGORITHM_STABLE_SORT_H11 12#include <__algorithm/comp.h>13#include <__algorithm/comp_ref_type.h>14#include <__algorithm/inplace_merge.h>15#include <__algorithm/iterator_operations.h>16#include <__algorithm/radix_sort.h>17#include <__algorithm/sort.h>18#include <__config>19#include <__cstddef/ptrdiff_t.h>20#include <__debug_utils/strict_weak_ordering_check.h>21#include <__iterator/iterator_traits.h>22#include <__memory/construct_at.h>23#include <__memory/destruct_n.h>24#include <__memory/unique_ptr.h>25#include <__memory/unique_temporary_buffer.h>26#include <__type_traits/desugars_to.h>27#include <__type_traits/enable_if.h>28#include <__type_traits/is_constant_evaluated.h>29#include <__type_traits/is_same.h>30#include <__type_traits/is_trivially_assignable.h>31#include <__utility/move.h>32#include <__utility/pair.h>33 34#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)35# pragma GCC system_header36#endif37 38_LIBCPP_PUSH_MACROS39#include <__undef_macros>40 41_LIBCPP_BEGIN_NAMESPACE_STD42 43template <class _AlgPolicy, class _Compare, class _BidirectionalIterator>44_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void __insertion_sort_move(45 _BidirectionalIterator __first1,46 _BidirectionalIterator __last1,47 typename iterator_traits<_BidirectionalIterator>::value_type* __first2,48 _Compare __comp) {49 using _Ops = _IterOps<_AlgPolicy>;50 51 typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;52 if (__first1 != __last1) {53 __destruct_n __d(0);54 unique_ptr<value_type, __destruct_n&> __h(__first2, __d);55 value_type* __last2 = __first2;56 std::__construct_at(__last2, _Ops::__iter_move(__first1));57 __d.template __incr<value_type>();58 for (++__last2; ++__first1 != __last1; ++__last2) {59 value_type* __j2 = __last2;60 value_type* __i2 = __j2;61 if (__comp(*__first1, *--__i2)) {62 std::__construct_at(__j2, std::move(*__i2));63 __d.template __incr<value_type>();64 for (--__j2; __i2 != __first2 && __comp(*__first1, *--__i2); --__j2)65 *__j2 = std::move(*__i2);66 *__j2 = _Ops::__iter_move(__first1);67 } else {68 std::__construct_at(__j2, _Ops::__iter_move(__first1));69 __d.template __incr<value_type>();70 }71 }72 __h.release();73 }74}75 76template <class _AlgPolicy, class _Compare, class _InputIterator1, class _InputIterator2>77_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void __merge_move_construct(78 _InputIterator1 __first1,79 _InputIterator1 __last1,80 _InputIterator2 __first2,81 _InputIterator2 __last2,82 typename iterator_traits<_InputIterator1>::value_type* __result,83 _Compare __comp) {84 using _Ops = _IterOps<_AlgPolicy>;85 86 typedef typename iterator_traits<_InputIterator1>::value_type value_type;87 __destruct_n __d(0);88 unique_ptr<value_type, __destruct_n&> __h(__result, __d);89 for (; true; ++__result) {90 if (__first1 == __last1) {91 for (; __first2 != __last2; ++__first2, (void)++__result, __d.template __incr<value_type>())92 std::__construct_at(__result, _Ops::__iter_move(__first2));93 __h.release();94 return;95 }96 if (__first2 == __last2) {97 for (; __first1 != __last1; ++__first1, (void)++__result, __d.template __incr<value_type>())98 std::__construct_at(__result, _Ops::__iter_move(__first1));99 __h.release();100 return;101 }102 if (__comp(*__first2, *__first1)) {103 std::__construct_at(__result, _Ops::__iter_move(__first2));104 __d.template __incr<value_type>();105 ++__first2;106 } else {107 std::__construct_at(__result, _Ops::__iter_move(__first1));108 __d.template __incr<value_type>();109 ++__first1;110 }111 }112}113 114template <class _AlgPolicy, class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>115_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void __merge_move_assign(116 _InputIterator1 __first1,117 _InputIterator1 __last1,118 _InputIterator2 __first2,119 _InputIterator2 __last2,120 _OutputIterator __result,121 _Compare __comp) {122 using _Ops = _IterOps<_AlgPolicy>;123 124 for (; __first1 != __last1; ++__result) {125 if (__first2 == __last2) {126 for (; __first1 != __last1; ++__first1, (void)++__result)127 *__result = _Ops::__iter_move(__first1);128 return;129 }130 if (__comp(*__first2, *__first1)) {131 *__result = _Ops::__iter_move(__first2);132 ++__first2;133 } else {134 *__result = _Ops::__iter_move(__first1);135 ++__first1;136 }137 }138 for (; __first2 != __last2; ++__first2, (void)++__result)139 *__result = _Ops::__iter_move(__first2);140}141 142template <class _AlgPolicy, class _Compare, class _RandomAccessIterator>143_LIBCPP_CONSTEXPR_SINCE_CXX26 void __stable_sort(144 _RandomAccessIterator __first,145 _RandomAccessIterator __last,146 _Compare __comp,147 typename iterator_traits<_RandomAccessIterator>::difference_type __len,148 typename iterator_traits<_RandomAccessIterator>::value_type* __buff,149 ptrdiff_t __buff_size);150 151template <class _AlgPolicy, class _Compare, class _RandomAccessIterator>152_LIBCPP_CONSTEXPR_SINCE_CXX26 void __stable_sort_move(153 _RandomAccessIterator __first1,154 _RandomAccessIterator __last1,155 _Compare __comp,156 typename iterator_traits<_RandomAccessIterator>::difference_type __len,157 typename iterator_traits<_RandomAccessIterator>::value_type* __first2) {158 using _Ops = _IterOps<_AlgPolicy>;159 160 typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;161 switch (__len) {162 case 0:163 return;164 case 1:165 std::__construct_at(__first2, _Ops::__iter_move(__first1));166 return;167 case 2:168 __destruct_n __d(0);169 unique_ptr<value_type, __destruct_n&> __h2(__first2, __d);170 if (__comp(*--__last1, *__first1)) {171 std::__construct_at(__first2, _Ops::__iter_move(__last1));172 __d.template __incr<value_type>();173 ++__first2;174 std::__construct_at(__first2, _Ops::__iter_move(__first1));175 } else {176 std::__construct_at(__first2, _Ops::__iter_move(__first1));177 __d.template __incr<value_type>();178 ++__first2;179 std::__construct_at(__first2, _Ops::__iter_move(__last1));180 }181 __h2.release();182 return;183 }184 if (__len <= 8) {185 std::__insertion_sort_move<_AlgPolicy, _Compare>(__first1, __last1, __first2, __comp);186 return;187 }188 typename iterator_traits<_RandomAccessIterator>::difference_type __l2 = __len / 2;189 _RandomAccessIterator __m = __first1 + __l2;190 std::__stable_sort<_AlgPolicy, _Compare>(__first1, __m, __comp, __l2, __first2, __l2);191 std::__stable_sort<_AlgPolicy, _Compare>(__m, __last1, __comp, __len - __l2, __first2 + __l2, __len - __l2);192 std::__merge_move_construct<_AlgPolicy, _Compare>(__first1, __m, __m, __last1, __first2, __comp);193}194 195template <class _Tp>196struct __stable_sort_switch {197 static const unsigned value = 128 * is_trivially_copy_assignable<_Tp>::value;198};199 200#if _LIBCPP_STD_VER >= 17201template <class _Tp>202_LIBCPP_HIDE_FROM_ABI constexpr unsigned __radix_sort_min_bound() {203 static_assert(__is_ordered_integer_representable_v<_Tp>);204 if constexpr (sizeof(_Tp) == 1) {205 return 1 << 8;206 }207 208 return 1 << 10;209}210 211template <class _Tp>212_LIBCPP_HIDE_FROM_ABI constexpr unsigned __radix_sort_max_bound() {213 static_assert(__is_ordered_integer_representable_v<_Tp>);214 if constexpr (sizeof(_Tp) >= 8) {215 return 1 << 15;216 }217 218 return 1 << 16;219}220#endif // _LIBCPP_STD_VER >= 17221 222template <class _AlgPolicy, class _Compare, class _RandomAccessIterator>223_LIBCPP_CONSTEXPR_SINCE_CXX26 void __stable_sort(224 _RandomAccessIterator __first,225 _RandomAccessIterator __last,226 _Compare __comp,227 typename iterator_traits<_RandomAccessIterator>::difference_type __len,228 typename iterator_traits<_RandomAccessIterator>::value_type* __buff,229 ptrdiff_t __buff_size) {230 typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;231 typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;232 switch (__len) {233 case 0:234 case 1:235 return;236 case 2:237 if (__comp(*--__last, *__first))238 _IterOps<_AlgPolicy>::iter_swap(__first, __last);239 return;240 }241 if (__len <= static_cast<difference_type>(__stable_sort_switch<value_type>::value)) {242 std::__insertion_sort<_AlgPolicy, _Compare>(__first, __last, __comp);243 return;244 }245 246#if _LIBCPP_STD_VER >= 17247 constexpr auto __default_comp = __desugars_to_v<__less_tag, _Compare, value_type, value_type >;248 constexpr auto __radix_sortable =249 __is_ordered_integer_representable_v<value_type> &&250 is_same_v< value_type&, __iterator_reference<_RandomAccessIterator>>;251 if constexpr (__default_comp && __radix_sortable) {252 if (__len <= __buff_size && __len >= static_cast<difference_type>(std::__radix_sort_min_bound<value_type>()) &&253 __len <= static_cast<difference_type>(std::__radix_sort_max_bound<value_type>())) {254 if (__libcpp_is_constant_evaluated()) {255 for (auto* __p = __buff; __p < __buff + __buff_size; ++__p) {256 std::__construct_at(__p);257 }258 }259 260 std::__radix_sort(__first, __last, __buff);261 return;262 }263 }264#endif // _LIBCPP_STD_VER >= 17265 266 typename iterator_traits<_RandomAccessIterator>::difference_type __l2 = __len / 2;267 _RandomAccessIterator __m = __first + __l2;268 if (__len <= __buff_size) {269 __destruct_n __d(0);270 unique_ptr<value_type, __destruct_n&> __h2(__buff, __d);271 std::__stable_sort_move<_AlgPolicy, _Compare>(__first, __m, __comp, __l2, __buff);272 __d.__set(__l2, (value_type*)nullptr);273 std::__stable_sort_move<_AlgPolicy, _Compare>(__m, __last, __comp, __len - __l2, __buff + __l2);274 __d.__set(__len, (value_type*)nullptr);275 std::__merge_move_assign<_AlgPolicy, _Compare>(276 __buff, __buff + __l2, __buff + __l2, __buff + __len, __first, __comp);277 // std::__merge<_Compare>(move_iterator<value_type*>(__buff),278 // move_iterator<value_type*>(__buff + __l2),279 // move_iterator<_RandomAccessIterator>(__buff + __l2),280 // move_iterator<_RandomAccessIterator>(__buff + __len),281 // __first, __comp);282 return;283 }284 std::__stable_sort<_AlgPolicy, _Compare>(__first, __m, __comp, __l2, __buff, __buff_size);285 std::__stable_sort<_AlgPolicy, _Compare>(__m, __last, __comp, __len - __l2, __buff, __buff_size);286 std::__inplace_merge<_AlgPolicy>(__first, __m, __last, __comp, __l2, __len - __l2, __buff, __buff_size);287}288 289template <class _AlgPolicy, class _RandomAccessIterator, class _Compare>290_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void291__stable_sort_impl(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare& __comp) {292 using value_type = typename iterator_traits<_RandomAccessIterator>::value_type;293 using difference_type = typename iterator_traits<_RandomAccessIterator>::difference_type;294 295 difference_type __len = __last - __first;296 __unique_temporary_buffer<value_type> __unique_buf;297 pair<value_type*, ptrdiff_t> __buf(0, 0);298 if (__len > static_cast<difference_type>(__stable_sort_switch<value_type>::value)) {299 __unique_buf = std::__allocate_unique_temporary_buffer<value_type>(__len);300 __buf.first = __unique_buf.get();301 __buf.second = __unique_buf.get_deleter().__count_;302 }303 304 std::__stable_sort<_AlgPolicy, __comp_ref_type<_Compare> >(__first, __last, __comp, __len, __buf.first, __buf.second);305 std::__check_strict_weak_ordering_sorted(__first, __last, __comp);306}307 308template <class _RandomAccessIterator, class _Compare>309_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void310stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {311 std::__stable_sort_impl<_ClassicAlgPolicy>(std::move(__first), std::move(__last), __comp);312}313 314template <class _RandomAccessIterator>315_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void316stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last) {317 std::stable_sort(__first, __last, __less<>());318}319 320_LIBCPP_END_NAMESPACE_STD321_LIBCPP_POP_MACROS322 323#endif // _LIBCPP___ALGORITHM_STABLE_SORT_H324