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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-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef _LIBCPP___PSTL_CPU_ALGOS_TRANSFORM_H
10#define _LIBCPP___PSTL_CPU_ALGOS_TRANSFORM_H
11
12#include <__algorithm/transform.h>
13#include <__assert>
14#include <__config>
15#include <__iterator/concepts.h>
16#include <__iterator/iterator_traits.h>
17#include <__pstl/backend_fwd.h>
18#include <__pstl/cpu_algos/cpu_traits.h>
19#include <__type_traits/is_execution_policy.h>
20#include <__utility/move.h>
21#include <optional>
22
23#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
24# pragma GCC system_header
25#endif
26
27_LIBCPP_PUSH_MACROS
28#include <__undef_macros>
29
30#if _LIBCPP_STD_VER >= 17
31
32_LIBCPP_BEGIN_NAMESPACE_STD
33namespace __pstl {
34
35template <class _Iterator1, class _DifferenceType, class _Iterator2, class _Function>
36_LIBCPP_HIDE_FROM_ABI _Iterator2
37__simd_transform(_Iterator1 __first1, _DifferenceType __n, _Iterator2 __first2, _Function __f) noexcept {
38 _PSTL_PRAGMA_SIMD
39 for (_DifferenceType __i = 0; __i < __n; ++__i)
40 __f(__first1[__i], __first2[__i]);
41 return __first2 + __n;
42}
43
44template <class _Iterator1, class _DifferenceType, class _Iterator2, class _Iterator3, class _Function>
45_LIBCPP_HIDE_FROM_ABI _Iterator3 __simd_transform(
46 _Iterator1 __first1, _DifferenceType __n, _Iterator2 __first2, _Iterator3 __first3, _Function __f) noexcept {
47 _PSTL_PRAGMA_SIMD
48 for (_DifferenceType __i = 0; __i < __n; ++__i)
49 __f(__first1[__i], __first2[__i], __first3[__i]);
50 return __first3 + __n;
51}
52
53template <class _Backend, class _RawExecutionPolicy>
54struct __cpu_parallel_transform {
55 template <class _Policy, class _ForwardIterator, class _ForwardOutIterator, class _UnaryOperation>
56 _LIBCPP_HIDE_FROM_ABI optional<_ForwardOutIterator>
57 operator()(_Policy&& __policy,
58 _ForwardIterator __first,
59 _ForwardIterator __last,
60 _ForwardOutIterator __result,
61 _UnaryOperation __op) const noexcept {
62 if constexpr (__is_parallel_execution_policy_v<_RawExecutionPolicy> &&
63 __has_random_access_iterator_category_or_concept<_ForwardIterator>::value &&
64 __has_random_access_iterator_category_or_concept<_ForwardOutIterator>::value) {
65 __cpu_traits<_Backend>::__for_each(
66 __first,
67 __last,
68 [&__policy, __op, __first, __result](_ForwardIterator __brick_first, _ForwardIterator __brick_last) {
69 using _TransformUnseq = __pstl::__transform<_Backend, __remove_parallel_policy_t<_RawExecutionPolicy>>;
70 auto __res = _TransformUnseq()(
71 std::__remove_parallel_policy(__policy),
72 __brick_first,
73 __brick_last,
74 __result + (__brick_first - __first),
75 __op);
76 _LIBCPP_ASSERT_INTERNAL(__res, "unseq/seq should never try to allocate!");
77 return *std::move(__res);
78 });
79 return __result + (__last - __first);
80 } else if constexpr (__is_unsequenced_execution_policy_v<_RawExecutionPolicy> &&
81 __has_random_access_iterator_category_or_concept<_ForwardIterator>::value &&
82 __has_random_access_iterator_category_or_concept<_ForwardOutIterator>::value) {
83 return __pstl::__simd_transform(
84 __first,
85 __last - __first,
86 __result,
87 [&](__iter_reference<_ForwardIterator> __in_value, __iter_reference<_ForwardOutIterator> __out_value) {
88 __out_value = __op(__in_value);
89 });
90 } else {
91 return std::transform(__first, __last, __result, __op);
92 }
93 }
94};
95
96template <class _Backend, class _RawExecutionPolicy>
97struct __cpu_parallel_transform_binary {
98 template <class _Policy,
99 class _ForwardIterator1,
100 class _ForwardIterator2,
101 class _ForwardOutIterator,
102 class _BinaryOperation>
103 _LIBCPP_HIDE_FROM_ABI optional<_ForwardOutIterator>
104 operator()(_Policy&& __policy,
105 _ForwardIterator1 __first1,
106 _ForwardIterator1 __last1,
107 _ForwardIterator2 __first2,
108 _ForwardOutIterator __result,
109 _BinaryOperation __op) const noexcept {
110 if constexpr (__is_parallel_execution_policy_v<_RawExecutionPolicy> &&
111 __has_random_access_iterator_category_or_concept<_ForwardIterator1>::value &&
112 __has_random_access_iterator_category_or_concept<_ForwardIterator2>::value &&
113 __has_random_access_iterator_category_or_concept<_ForwardOutIterator>::value) {
114 auto __res = __cpu_traits<_Backend>::__for_each(
115 __first1,
116 __last1,
117 [&__policy, __op, __first1, __first2, __result](
118 _ForwardIterator1 __brick_first, _ForwardIterator1 __brick_last) {
119 using _TransformBinaryUnseq =
120 __pstl::__transform_binary<_Backend, __remove_parallel_policy_t<_RawExecutionPolicy>>;
121 return _TransformBinaryUnseq()(
122 std::__remove_parallel_policy(__policy),
123 __brick_first,
124 __brick_last,
125 __first2 + (__brick_first - __first1),
126 __result + (__brick_first - __first1),
127 __op);
128 });
129 if (!__res)
130 return nullopt;
131 return __result + (__last1 - __first1);
132 } else if constexpr (__is_unsequenced_execution_policy_v<_RawExecutionPolicy> &&
133 __has_random_access_iterator_category_or_concept<_ForwardIterator1>::value &&
134 __has_random_access_iterator_category_or_concept<_ForwardIterator2>::value &&
135 __has_random_access_iterator_category_or_concept<_ForwardOutIterator>::value) {
136 return __pstl::__simd_transform(
137 __first1,
138 __last1 - __first1,
139 __first2,
140 __result,
141 [&](__iter_reference<_ForwardIterator1> __in1,
142 __iter_reference<_ForwardIterator2> __in2,
143 __iter_reference<_ForwardOutIterator> __out_value) { __out_value = __op(__in1, __in2); });
144 } else {
145 return std::transform(__first1, __last1, __first2, __result, __op);
146 }
147 }
148};
149
150} // namespace __pstl
151_LIBCPP_END_NAMESPACE_STD
152
153#endif // _LIBCPP_STD_VER >= 17
154
155_LIBCPP_POP_MACROS
156
157#endif // _LIBCPP___PSTL_CPU_ALGOS_TRANSFORM_H