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