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_FILL_H
10#define _LIBCPP___PSTL_CPU_ALGOS_FILL_H
11
12#include <__algorithm/fill.h>
13#include <__assert>
14#include <__config>
15#include <__iterator/concepts.h>
16#include <__pstl/backend_fwd.h>
17#include <__pstl/cpu_algos/cpu_traits.h>
18#include <__type_traits/is_execution_policy.h>
19#include <__utility/empty.h>
20#include <optional>
21
22#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
23# pragma GCC system_header
24#endif
25
26_LIBCPP_BEGIN_NAMESPACE_STD
27namespace __pstl {
28
29template <class _Index, class _DifferenceType, class _Tp>
30_LIBCPP_HIDE_FROM_ABI _Index __simd_fill_n(_Index __first, _DifferenceType __n, const _Tp& __value) noexcept {
31 _PSTL_USE_NONTEMPORAL_STORES_IF_ALLOWED
32 _PSTL_PRAGMA_SIMD
33 for (_DifferenceType __i = 0; __i < __n; ++__i)
34 __first[__i] = __value;
35 return __first + __n;
36}
37
38template <class _Backend, class _RawExecutionPolicy>
39struct __cpu_parallel_fill {
40 template <class _Policy, class _ForwardIterator, class _Tp>
41 _LIBCPP_HIDE_FROM_ABI optional<__empty>
42 operator()(_Policy&& __policy, _ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) const noexcept {
43 if constexpr (__is_parallel_execution_policy_v<_RawExecutionPolicy> &&
44 __has_random_access_iterator_category_or_concept<_ForwardIterator>::value) {
45 return __cpu_traits<_Backend>::__for_each(
46 __first, __last, [&__policy, &__value](_ForwardIterator __brick_first, _ForwardIterator __brick_last) {
47 using _FillUnseq = __pstl::__fill<_Backend, __remove_parallel_policy_t<_RawExecutionPolicy>>;
48 [[maybe_unused]] auto __res =
49 _FillUnseq()(std::__remove_parallel_policy(__policy), __brick_first, __brick_last, __value);
50 _LIBCPP_ASSERT_INTERNAL(__res, "unseq/seq should never try to allocate!");
51 });
52 } else if constexpr (__is_unsequenced_execution_policy_v<_RawExecutionPolicy> &&
53 __has_random_access_iterator_category_or_concept<_ForwardIterator>::value) {
54 __pstl::__simd_fill_n(__first, __last - __first, __value);
55 return __empty{};
56 } else {
57 std::fill(__first, __last, __value);
58 return __empty{};
59 }
60 }
61};
62
63} // namespace __pstl
64_LIBCPP_END_NAMESPACE_STD
65
66#endif // _LIBCPP___PSTL_CPU_ALGOS_FILL_H
67