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___ALGORITHM_PSTL_BACKENDS_CPU_BACKENDS_TRANSFORM_H
10 #define _LIBCPP___ALGORITHM_PSTL_BACKENDS_CPU_BACKENDS_TRANSFORM_H
11
12 #include <__algorithm/pstl_backends/cpu_backends/backend.h>
13 #include <__algorithm/transform.h>
14 #include <__config>
15 #include <__iterator/concepts.h>
16 #include <__iterator/iterator_traits.h>
17 #include <__type_traits/enable_if.h>
18 #include <__type_traits/is_execution_policy.h>
19 #include <__type_traits/remove_cvref.h>
20 #include <optional>
21
22 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
23 # pragma GCC system_header
24 #endif
25
26 #if !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
27
28 _LIBCPP_PUSH_MACROS
29 # include <__undef_macros>
30
31 _LIBCPP_BEGIN_NAMESPACE_STD
32
33 template <class _Iterator1, class _DifferenceType, class _Iterator2, class _Function>
34 _LIBCPP_HIDE_FROM_ABI _Iterator2
__simd_walk(_Iterator1 __first1,_DifferenceType __n,_Iterator2 __first2,_Function __f)35 __simd_walk(_Iterator1 __first1, _DifferenceType __n, _Iterator2 __first2, _Function __f) noexcept {
36 _PSTL_PRAGMA_SIMD
37 for (_DifferenceType __i = 0; __i < __n; ++__i)
38 __f(__first1[__i], __first2[__i]);
39 return __first2 + __n;
40 }
41
42 template <class _ExecutionPolicy, class _ForwardIterator, class _ForwardOutIterator, class _UnaryOperation>
__pstl_transform(__cpu_backend_tag,_ForwardIterator __first,_ForwardIterator __last,_ForwardOutIterator __result,_UnaryOperation __op)43 _LIBCPP_HIDE_FROM_ABI optional<_ForwardOutIterator> __pstl_transform(
44 __cpu_backend_tag,
45 _ForwardIterator __first,
46 _ForwardIterator __last,
47 _ForwardOutIterator __result,
48 _UnaryOperation __op) {
49 if constexpr (__is_parallel_execution_policy_v<_ExecutionPolicy> &&
50 __has_random_access_iterator_category_or_concept<_ForwardIterator>::value &&
51 __has_random_access_iterator_category_or_concept<_ForwardOutIterator>::value) {
52 std::__par_backend::__parallel_for(
53 __first, __last, [__op, __first, __result](_ForwardIterator __brick_first, _ForwardIterator __brick_last) {
54 auto __res = std::__pstl_transform<__remove_parallel_policy_t<_ExecutionPolicy>>(
55 __cpu_backend_tag{}, __brick_first, __brick_last, __result + (__brick_first - __first), __op);
56 _LIBCPP_ASSERT_INTERNAL(__res, "unseq/seq should never try to allocate!");
57 return *std::move(__res);
58 });
59 return __result + (__last - __first);
60 } else if constexpr (__is_unsequenced_execution_policy_v<_ExecutionPolicy> &&
61 __has_random_access_iterator_category_or_concept<_ForwardIterator>::value &&
62 __has_random_access_iterator_category_or_concept<_ForwardOutIterator>::value) {
63 return std::__simd_walk(
64 __first,
65 __last - __first,
66 __result,
67 [&](__iter_reference<_ForwardIterator> __in_value, __iter_reference<_ForwardOutIterator> __out_value) {
68 __out_value = __op(__in_value);
69 });
70 } else {
71 return std::transform(__first, __last, __result, __op);
72 }
73 }
74
75 template <class _Iterator1, class _DifferenceType, class _Iterator2, class _Iterator3, class _Function>
__simd_walk(_Iterator1 __first1,_DifferenceType __n,_Iterator2 __first2,_Iterator3 __first3,_Function __f)76 _LIBCPP_HIDE_FROM_ABI _Iterator3 __simd_walk(
77 _Iterator1 __first1, _DifferenceType __n, _Iterator2 __first2, _Iterator3 __first3, _Function __f) noexcept {
78 _PSTL_PRAGMA_SIMD
79 for (_DifferenceType __i = 0; __i < __n; ++__i)
80 __f(__first1[__i], __first2[__i], __first3[__i]);
81 return __first3 + __n;
82 }
83 template <class _ExecutionPolicy,
84 class _ForwardIterator1,
85 class _ForwardIterator2,
86 class _ForwardOutIterator,
87 class _BinaryOperation,
88 enable_if_t<is_execution_policy_v<__remove_cvref_t<_ExecutionPolicy>>, int> = 0>
__pstl_transform(__cpu_backend_tag,_ForwardIterator1 __first1,_ForwardIterator1 __last1,_ForwardIterator2 __first2,_ForwardOutIterator __result,_BinaryOperation __op)89 _LIBCPP_HIDE_FROM_ABI optional<_ForwardOutIterator> __pstl_transform(
90 __cpu_backend_tag,
91 _ForwardIterator1 __first1,
92 _ForwardIterator1 __last1,
93 _ForwardIterator2 __first2,
94 _ForwardOutIterator __result,
95 _BinaryOperation __op) {
96 if constexpr (__is_parallel_execution_policy_v<_ExecutionPolicy> &&
97 __has_random_access_iterator_category_or_concept<_ForwardIterator1>::value &&
98 __has_random_access_iterator_category_or_concept<_ForwardIterator2>::value &&
99 __has_random_access_iterator_category_or_concept<_ForwardOutIterator>::value) {
100 auto __res = std::__par_backend::__parallel_for(
101 __first1,
102 __last1,
103 [__op, __first1, __first2, __result](_ForwardIterator1 __brick_first, _ForwardIterator1 __brick_last) {
104 return std::__pstl_transform<__remove_parallel_policy_t<_ExecutionPolicy>>(
105 __cpu_backend_tag{},
106 __brick_first,
107 __brick_last,
108 __first2 + (__brick_first - __first1),
109 __result + (__brick_first - __first1),
110 __op);
111 });
112 if (!__res)
113 return nullopt;
114 return __result + (__last1 - __first1);
115 } else if constexpr (__is_unsequenced_execution_policy_v<_ExecutionPolicy> &&
116 __has_random_access_iterator_category_or_concept<_ForwardIterator1>::value &&
117 __has_random_access_iterator_category_or_concept<_ForwardIterator2>::value &&
118 __has_random_access_iterator_category_or_concept<_ForwardOutIterator>::value) {
119 return std::__simd_walk(
120 __first1,
121 __last1 - __first1,
122 __first2,
123 __result,
124 [&](__iter_reference<_ForwardIterator1> __in1,
125 __iter_reference<_ForwardIterator2> __in2,
126 __iter_reference<_ForwardOutIterator> __out_value) { __out_value = __op(__in1, __in2); });
127 } else {
128 return std::transform(__first1, __last1, __first2, __result, __op);
129 }
130 }
131
132 _LIBCPP_END_NAMESPACE_STD
133
134 _LIBCPP_POP_MACROS
135
136 #endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
137
138 #endif // _LIBCPP___ALGORITHM_PSTL_BACKENDS_CPU_BACKENDS_TRANSFORM_H
139