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
40template <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
52template <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
60template <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
121template <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
133template <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
153template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
154[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_InputIterator1, _InputIterator2>
155mismatch(_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
162template <class _InputIterator1, class _InputIterator2>
163[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_InputIterator1, _InputIterator2>
164mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2) {
165 return std::mismatch(__first1, __last1, __first2, __equal_to());
166}
167
168#if _LIBCPP_STD_VER >= 14
169template <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
181template <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
188template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
189[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_InputIterator1, _InputIterator2>
190mismatch(_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
207template <class _InputIterator1, class _InputIterator2>
208[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_InputIterator1, _InputIterator2>
209mismatch(_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