1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef _LIBCPP___ALGORITHM_MISMATCH_H 11 #define _LIBCPP___ALGORITHM_MISMATCH_H 12 13 #include <__algorithm/comp.h> 14 #include <__algorithm/min.h> 15 #include <__algorithm/simd_utils.h> 16 #include <__algorithm/unwrap_iter.h> 17 #include <__config> 18 #include <__functional/identity.h> 19 #include <__iterator/aliasing_iterator.h> 20 #include <__iterator/iterator_traits.h> 21 #include <__type_traits/desugars_to.h> 22 #include <__type_traits/enable_if.h> 23 #include <__type_traits/invoke.h> 24 #include <__type_traits/is_constant_evaluated.h> 25 #include <__type_traits/is_equality_comparable.h> 26 #include <__type_traits/is_integral.h> 27 #include <__utility/move.h> 28 #include <__utility/pair.h> 29 #include <__utility/unreachable.h> 30 #include <cstddef> 31 32 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 33 # pragma GCC system_header 34 #endif 35 36 _LIBCPP_PUSH_MACROS 37 #include <__undef_macros> 38 39 _LIBCPP_BEGIN_NAMESPACE_STD 40 41 template <class _Iter1, class _Sent1, class _Iter2, class _Pred, class _Proj1, class _Proj2> 42 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_Iter1, _Iter2> 43 __mismatch_loop(_Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Pred& __pred, _Proj1& __proj1, _Proj2& __proj2) { 44 while (__first1 != __last1) { 45 if (!std::__invoke(__pred, std::__invoke(__proj1, *__first1), std::__invoke(__proj2, *__first2))) 46 break; 47 ++__first1; 48 ++__first2; 49 } 50 return std::make_pair(std::move(__first1), std::move(__first2)); 51 } 52 53 template <class _Iter1, class _Sent1, class _Iter2, class _Pred, class _Proj1, class _Proj2> 54 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_Iter1, _Iter2> 55 __mismatch(_Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Pred& __pred, _Proj1& __proj1, _Proj2& __proj2) { 56 return std::__mismatch_loop(__first1, __last1, __first2, __pred, __proj1, __proj2); 57 } 58 59 #if _LIBCPP_VECTORIZE_ALGORITHMS 60 61 template <class _Iter> 62 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_Iter, _Iter> 63 __mismatch_vectorized(_Iter __first1, _Iter __last1, _Iter __first2) { 64 using __value_type = __iter_value_type<_Iter>; 65 constexpr size_t __unroll_count = 4; 66 constexpr size_t __vec_size = __native_vector_size<__value_type>; 67 using __vec = __simd_vector<__value_type, __vec_size>; 68 69 if (!__libcpp_is_constant_evaluated()) { 70 auto __orig_first1 = __first1; 71 auto __last2 = __first2 + (__last1 - __first1); 72 while (static_cast<size_t>(__last1 - __first1) >= __unroll_count * __vec_size) [[__unlikely__]] { 73 __vec __lhs[__unroll_count]; 74 __vec __rhs[__unroll_count]; 75 76 for (size_t __i = 0; __i != __unroll_count; ++__i) { 77 __lhs[__i] = std::__load_vector<__vec>(__first1 + __i * __vec_size); 78 __rhs[__i] = std::__load_vector<__vec>(__first2 + __i * __vec_size); 79 } 80 81 for (size_t __i = 0; __i != __unroll_count; ++__i) { 82 if (auto __cmp_res = __lhs[__i] == __rhs[__i]; !std::__all_of(__cmp_res)) { 83 auto __offset = __i * __vec_size + std::__find_first_not_set(__cmp_res); 84 return {__first1 + __offset, __first2 + __offset}; 85 } 86 } 87 88 __first1 += __unroll_count * __vec_size; 89 __first2 += __unroll_count * __vec_size; 90 } 91 92 // check the remaining 0-3 vectors 93 while (static_cast<size_t>(__last1 - __first1) >= __vec_size) { 94 if (auto __cmp_res = std::__load_vector<__vec>(__first1) == std::__load_vector<__vec>(__first2); 95 !std::__all_of(__cmp_res)) { 96 auto __offset = std::__find_first_not_set(__cmp_res); 97 return {__first1 + __offset, __first2 + __offset}; 98 } 99 __first1 += __vec_size; 100 __first2 += __vec_size; 101 } 102 103 if (__last1 - __first1 == 0) 104 return {__first1, __first2}; 105 106 // Check if we can load elements in front of the current pointer. If that's the case load a vector at 107 // (last - vector_size) to check the remaining elements 108 if (static_cast<size_t>(__first1 - __orig_first1) >= __vec_size) { 109 __first1 = __last1 - __vec_size; 110 __first2 = __last2 - __vec_size; 111 auto __offset = 112 std::__find_first_not_set(std::__load_vector<__vec>(__first1) == std::__load_vector<__vec>(__first2)); 113 return {__first1 + __offset, __first2 + __offset}; 114 } // else loop over the elements individually 115 } 116 117 __equal_to __pred; 118 __identity __proj; 119 return std::__mismatch_loop(__first1, __last1, __first2, __pred, __proj, __proj); 120 } 121 122 template <class _Tp, 123 class _Pred, 124 class _Proj1, 125 class _Proj2, 126 __enable_if_t<is_integral<_Tp>::value && __desugars_to_v<__equal_tag, _Pred, _Tp, _Tp> && 127 __is_identity<_Proj1>::value && __is_identity<_Proj2>::value, 128 int> = 0> 129 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_Tp*, _Tp*> 130 __mismatch(_Tp* __first1, _Tp* __last1, _Tp* __first2, _Pred&, _Proj1&, _Proj2&) { 131 return std::__mismatch_vectorized(__first1, __last1, __first2); 132 } 133 134 template <class _Tp, 135 class _Pred, 136 class _Proj1, 137 class _Proj2, 138 __enable_if_t<!is_integral<_Tp>::value && __desugars_to_v<__equal_tag, _Pred, _Tp, _Tp> && 139 __is_identity<_Proj1>::value && __is_identity<_Proj2>::value && 140 __can_map_to_integer_v<_Tp> && __libcpp_is_trivially_equality_comparable<_Tp, _Tp>::value, 141 int> = 0> 142 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_Tp*, _Tp*> 143 __mismatch(_Tp* __first1, _Tp* __last1, _Tp* __first2, _Pred& __pred, _Proj1& __proj1, _Proj2& __proj2) { 144 if (__libcpp_is_constant_evaluated()) { 145 return std::__mismatch_loop(__first1, __last1, __first2, __pred, __proj1, __proj2); 146 } else { 147 using _Iter = __aliasing_iterator<_Tp*, __get_as_integer_type_t<_Tp>>; 148 auto __ret = std::__mismatch_vectorized(_Iter(__first1), _Iter(__last1), _Iter(__first2)); 149 return {__ret.first.__base(), __ret.second.__base()}; 150 } 151 } 152 #endif // _LIBCPP_VECTORIZE_ALGORITHMS 153 154 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate> 155 [[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_InputIterator1, _InputIterator2> 156 mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred) { 157 __identity __proj; 158 auto __res = std::__mismatch( 159 std::__unwrap_iter(__first1), std::__unwrap_iter(__last1), std::__unwrap_iter(__first2), __pred, __proj, __proj); 160 return std::make_pair(std::__rewrap_iter(__first1, __res.first), std::__rewrap_iter(__first2, __res.second)); 161 } 162 163 template <class _InputIterator1, class _InputIterator2> 164 [[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_InputIterator1, _InputIterator2> 165 mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2) { 166 return std::mismatch(__first1, __last1, __first2, __equal_to()); 167 } 168 169 #if _LIBCPP_STD_VER >= 14 170 template <class _Iter1, class _Sent1, class _Iter2, class _Sent2, class _Pred, class _Proj1, class _Proj2> 171 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_Iter1, _Iter2> __mismatch( 172 _Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2, _Pred& __pred, _Proj1& __proj1, _Proj2& __proj2) { 173 while (__first1 != __last1 && __first2 != __last2) { 174 if (!std::__invoke(__pred, std::__invoke(__proj1, *__first1), std::__invoke(__proj2, *__first2))) 175 break; 176 ++__first1; 177 ++__first2; 178 } 179 return {std::move(__first1), std::move(__first2)}; 180 } 181 182 template <class _Tp, class _Pred, class _Proj1, class _Proj2> 183 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_Tp*, _Tp*> 184 __mismatch(_Tp* __first1, _Tp* __last1, _Tp* __first2, _Tp* __last2, _Pred& __pred, _Proj1& __proj1, _Proj2& __proj2) { 185 auto __len = std::min(__last1 - __first1, __last2 - __first2); 186 return std::__mismatch(__first1, __first1 + __len, __first2, __pred, __proj1, __proj2); 187 } 188 189 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate> 190 [[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_InputIterator1, _InputIterator2> 191 mismatch(_InputIterator1 __first1, 192 _InputIterator1 __last1, 193 _InputIterator2 __first2, 194 _InputIterator2 __last2, 195 _BinaryPredicate __pred) { 196 __identity __proj; 197 auto __res = std::__mismatch( 198 std::__unwrap_iter(__first1), 199 std::__unwrap_iter(__last1), 200 std::__unwrap_iter(__first2), 201 std::__unwrap_iter(__last2), 202 __pred, 203 __proj, 204 __proj); 205 return {std::__rewrap_iter(__first1, __res.first), std::__rewrap_iter(__first2, __res.second)}; 206 } 207 208 template <class _InputIterator1, class _InputIterator2> 209 [[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_InputIterator1, _InputIterator2> 210 mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2) { 211 return std::mismatch(__first1, __last1, __first2, __last2, __equal_to()); 212 } 213 #endif 214 215 _LIBCPP_END_NAMESPACE_STD 216 217 _LIBCPP_POP_MACROS 218 219 #endif // _LIBCPP___ALGORITHM_MISMATCH_H 220