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_BACKENDS_STD_THREAD_H
10#define _LIBCPP___PSTL_BACKENDS_STD_THREAD_H
11
12#include <__config>
13#include <__pstl/backend_fwd.h>
14#include <__pstl/cpu_algos/any_of.h>
15#include <__pstl/cpu_algos/cpu_traits.h>
16#include <__pstl/cpu_algos/fill.h>
17#include <__pstl/cpu_algos/find_if.h>
18#include <__pstl/cpu_algos/for_each.h>
19#include <__pstl/cpu_algos/merge.h>
20#include <__pstl/cpu_algos/stable_sort.h>
21#include <__pstl/cpu_algos/transform.h>
22#include <__pstl/cpu_algos/transform_reduce.h>
23#include <__utility/empty.h>
24#include <__utility/move.h>
25#include <optional>
26
27#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
28# pragma GCC system_header
29#endif
30
31_LIBCPP_PUSH_MACROS
32#include <__undef_macros>
33
34#if _LIBCPP_STD_VER >= 17
35
36_LIBCPP_BEGIN_NAMESPACE_STD
37namespace __pstl {
38
39//
40// This partial backend implementation is for testing purposes only and not meant for production use. This will be
41// replaced by a proper implementation once the PSTL implementation is somewhat stable.
42//
43// This is intended to be used on top of the "default backend".
44//
45
46template <>
47struct __cpu_traits<__std_thread_backend_tag> {
48 template <class _RandomAccessIterator, class _Fp>
49 _LIBCPP_HIDE_FROM_ABI static optional<__empty>
50 __for_each(_RandomAccessIterator __first, _RandomAccessIterator __last, _Fp __f) {
51 __f(__first, __last);
52 return __empty{};
53 }
54
55 template <class _Index, class _UnaryOp, class _Tp, class _BinaryOp, class _Reduce>
56 _LIBCPP_HIDE_FROM_ABI static optional<_Tp>
57 __transform_reduce(_Index __first, _Index __last, _UnaryOp, _Tp __init, _BinaryOp, _Reduce __reduce) {
58 return __reduce(std::move(__first), std::move(__last), std::move(__init));
59 }
60
61 template <class _RandomAccessIterator, class _Compare, class _LeafSort>
62 _LIBCPP_HIDE_FROM_ABI static optional<__empty>
63 __stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp, _LeafSort __leaf_sort) {
64 __leaf_sort(__first, __last, __comp);
65 return __empty{};
66 }
67
68 _LIBCPP_HIDE_FROM_ABI static void __cancel_execution() {}
69
70 template <class _RandomAccessIterator1,
71 class _RandomAccessIterator2,
72 class _RandomAccessIterator3,
73 class _Compare,
74 class _LeafMerge>
75 _LIBCPP_HIDE_FROM_ABI static optional<__empty>
76 __merge(_RandomAccessIterator1 __first1,
77 _RandomAccessIterator1 __last1,
78 _RandomAccessIterator2 __first2,
79 _RandomAccessIterator2 __last2,
80 _RandomAccessIterator3 __outit,
81 _Compare __comp,
82 _LeafMerge __leaf_merge) {
83 __leaf_merge(__first1, __last1, __first2, __last2, __outit, __comp);
84 return __empty{};
85 }
86
87 static constexpr size_t __lane_size = 64;
88};
89
90// Mandatory implementations of the computational basis
91template <class _ExecutionPolicy>
92struct __find_if<__std_thread_backend_tag, _ExecutionPolicy>
93 : __cpu_parallel_find_if<__std_thread_backend_tag, _ExecutionPolicy> {};
94
95template <class _ExecutionPolicy>
96struct __for_each<__std_thread_backend_tag, _ExecutionPolicy>
97 : __cpu_parallel_for_each<__std_thread_backend_tag, _ExecutionPolicy> {};
98
99template <class _ExecutionPolicy>
100struct __merge<__std_thread_backend_tag, _ExecutionPolicy>
101 : __cpu_parallel_merge<__std_thread_backend_tag, _ExecutionPolicy> {};
102
103template <class _ExecutionPolicy>
104struct __stable_sort<__std_thread_backend_tag, _ExecutionPolicy>
105 : __cpu_parallel_stable_sort<__std_thread_backend_tag, _ExecutionPolicy> {};
106
107template <class _ExecutionPolicy>
108struct __transform<__std_thread_backend_tag, _ExecutionPolicy>
109 : __cpu_parallel_transform<__std_thread_backend_tag, _ExecutionPolicy> {};
110
111template <class _ExecutionPolicy>
112struct __transform_binary<__std_thread_backend_tag, _ExecutionPolicy>
113 : __cpu_parallel_transform_binary<__std_thread_backend_tag, _ExecutionPolicy> {};
114
115template <class _ExecutionPolicy>
116struct __transform_reduce<__std_thread_backend_tag, _ExecutionPolicy>
117 : __cpu_parallel_transform_reduce<__std_thread_backend_tag, _ExecutionPolicy> {};
118
119template <class _ExecutionPolicy>
120struct __transform_reduce_binary<__std_thread_backend_tag, _ExecutionPolicy>
121 : __cpu_parallel_transform_reduce_binary<__std_thread_backend_tag, _ExecutionPolicy> {};
122
123// Not mandatory, but better optimized
124template <class _ExecutionPolicy>
125struct __any_of<__std_thread_backend_tag, _ExecutionPolicy>
126 : __cpu_parallel_any_of<__std_thread_backend_tag, _ExecutionPolicy> {};
127
128template <class _ExecutionPolicy>
129struct __fill<__std_thread_backend_tag, _ExecutionPolicy>
130 : __cpu_parallel_fill<__std_thread_backend_tag, _ExecutionPolicy> {};
131
132} // namespace __pstl
133_LIBCPP_END_NAMESPACE_STD
134
135#endif // _LIBCPP_STD_VER >= 17
136
137_LIBCPP_POP_MACROS
138
139#endif // _LIBCPP___PSTL_BACKENDS_STD_THREAD_H
140