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_BACKNEDS_FOR_EACH_H
10#define _LIBCPP___ALGORITHM_PSTL_BACKENDS_CPU_BACKNEDS_FOR_EACH_H
11
12#include <__algorithm/for_each.h>
13#include <__algorithm/pstl_backends/cpu_backends/backend.h>
14#include <__config>
15#include <__iterator/concepts.h>
16#include <__type_traits/is_execution_policy.h>
17#include <__utility/empty.h>
18#include <optional>
19
20#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
21#  pragma GCC system_header
22#endif
23
24#if !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
25
26_LIBCPP_BEGIN_NAMESPACE_STD
27
28template <class _Iterator, class _DifferenceType, class _Function>
29_LIBCPP_HIDE_FROM_ABI _Iterator __simd_walk(_Iterator __first, _DifferenceType __n, _Function __f) noexcept {
30  _PSTL_PRAGMA_SIMD
31  for (_DifferenceType __i = 0; __i < __n; ++__i)
32    __f(__first[__i]);
33
34  return __first + __n;
35}
36
37template <class _ExecutionPolicy, class _ForwardIterator, class _Functor>
38_LIBCPP_HIDE_FROM_ABI optional<__empty>
39__pstl_for_each(__cpu_backend_tag, _ForwardIterator __first, _ForwardIterator __last, _Functor __func) {
40  if constexpr (__is_parallel_execution_policy_v<_ExecutionPolicy> &&
41                __has_random_access_iterator_category_or_concept<_ForwardIterator>::value) {
42    return std::__par_backend::__parallel_for(
43        __first, __last, [__func](_ForwardIterator __brick_first, _ForwardIterator __brick_last) {
44          [[maybe_unused]] auto __res = std::__pstl_for_each<__remove_parallel_policy_t<_ExecutionPolicy>>(
45              __cpu_backend_tag{}, __brick_first, __brick_last, __func);
46          _LIBCPP_ASSERT_INTERNAL(__res, "unseq/seq should never try to allocate!");
47        });
48  } else if constexpr (__is_unsequenced_execution_policy_v<_ExecutionPolicy> &&
49                       __has_random_access_iterator_category_or_concept<_ForwardIterator>::value) {
50    std::__simd_walk(__first, __last - __first, __func);
51    return __empty{};
52  } else {
53    std::for_each(__first, __last, __func);
54    return __empty{};
55  }
56}
57
58_LIBCPP_END_NAMESPACE_STD
59
60#endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
61
62#endif // _LIBCPP___ALGORITHM_PSTL_BACKENDS_CPU_BACKNEDS_FOR_EACH_H
63