d423d80e56
This patch removes the two-level backend dispatching mechanism we had in the PSTL. Instead of selecting both a PSTL backend and a PSTL CPU backend, we now only select a top-level PSTL backend. This greatly simplifies the PSTL configuration layer. While this patch technically removes some flexibility from the PSTL configuration mechanism because CPU backends are not considered separately, it opens the door to a much more powerful configuration mechanism based on chained backends in a follow-up patch. This is a step towards overhauling the PSTL dispatching mechanism.
127 lines
5.0 KiB
C++
127 lines
5.0 KiB
C++
//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef _LIBCPP___ALGORITHM_PSTL_COUNT_H
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#define _LIBCPP___ALGORITHM_PSTL_COUNT_H
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#include <__algorithm/count.h>
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#include <__algorithm/for_each.h>
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#include <__algorithm/pstl_for_each.h>
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#include <__algorithm/pstl_frontend_dispatch.h>
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#include <__atomic/atomic.h>
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#include <__config>
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#include <__functional/operations.h>
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#include <__iterator/cpp17_iterator_concepts.h>
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#include <__iterator/iterator_traits.h>
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#include <__numeric/pstl_transform_reduce.h>
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#include <__pstl/configuration.h>
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#include <__type_traits/enable_if.h>
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#include <__type_traits/is_execution_policy.h>
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#include <__type_traits/remove_cvref.h>
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#include <__utility/move.h>
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#include <optional>
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#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
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# pragma GCC system_header
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#endif
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_LIBCPP_PUSH_MACROS
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#include <__undef_macros>
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#if !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
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_LIBCPP_BEGIN_NAMESPACE_STD
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template <class>
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void __pstl_count_if(); // declaration needed for the frontend dispatch below
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template <class _ExecutionPolicy,
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class _ForwardIterator,
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class _Predicate,
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class _RawPolicy = __remove_cvref_t<_ExecutionPolicy>,
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enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
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[[nodiscard]] _LIBCPP_HIDE_FROM_ABI optional<__iter_diff_t<_ForwardIterator>> __count_if(
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_ExecutionPolicy&& __policy, _ForwardIterator&& __first, _ForwardIterator&& __last, _Predicate&& __pred) noexcept {
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using __diff_t = __iter_diff_t<_ForwardIterator>;
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return std::__pstl_frontend_dispatch(
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_LIBCPP_PSTL_CUSTOMIZATION_POINT(__pstl_count_if, _RawPolicy),
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[&](_ForwardIterator __g_first, _ForwardIterator __g_last, _Predicate __g_pred) -> optional<__diff_t> {
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return std::__transform_reduce(
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__policy,
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std::move(__g_first),
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std::move(__g_last),
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__diff_t(),
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std::plus{},
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[&](__iter_reference<_ForwardIterator> __element) -> bool { return __g_pred(__element); });
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},
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std::move(__first),
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std::move(__last),
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std::move(__pred));
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}
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template <class _ExecutionPolicy,
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class _ForwardIterator,
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class _Predicate,
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class _RawPolicy = __remove_cvref_t<_ExecutionPolicy>,
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enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
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_LIBCPP_HIDE_FROM_ABI __iter_diff_t<_ForwardIterator>
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count_if(_ExecutionPolicy&& __policy, _ForwardIterator __first, _ForwardIterator __last, _Predicate __pred) {
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_LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(
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_ForwardIterator, "count_if(first, last, pred) requires [first, last) to be ForwardIterators");
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auto __res = std::__count_if(__policy, std::move(__first), std::move(__last), std::move(__pred));
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if (!__res)
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std::__throw_bad_alloc();
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return *std::move(__res);
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}
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template <class>
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void __pstl_count(); // declaration needed for the frontend dispatch below
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template <class _ExecutionPolicy,
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class _ForwardIterator,
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class _Tp,
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class _RawPolicy = __remove_cvref_t<_ExecutionPolicy>,
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enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
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[[nodiscard]] _LIBCPP_HIDE_FROM_ABI optional<__iter_diff_t<_ForwardIterator>>
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__count(_ExecutionPolicy&& __policy, _ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) {
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return std::__pstl_frontend_dispatch(
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_LIBCPP_PSTL_CUSTOMIZATION_POINT(__pstl_count, _RawPolicy),
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[&](_ForwardIterator __g_first, _ForwardIterator __g_last, const _Tp& __g_value)
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-> optional<__iter_diff_t<_ForwardIterator>> {
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return std::count_if(__policy, __g_first, __g_last, [&](__iter_reference<_ForwardIterator> __v) {
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return __v == __g_value;
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});
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},
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std::move(__first),
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std::move(__last),
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__value);
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}
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template <class _ExecutionPolicy,
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class _ForwardIterator,
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class _Tp,
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class _RawPolicy = __remove_cvref_t<_ExecutionPolicy>,
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enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
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_LIBCPP_HIDE_FROM_ABI __iter_diff_t<_ForwardIterator>
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count(_ExecutionPolicy&& __policy, _ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) {
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_LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(
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_ForwardIterator, "count(first, last, val) requires [first, last) to be ForwardIterators");
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auto __res = std::__count(__policy, std::move(__first), std::move(__last), __value);
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if (!__res)
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std::__throw_bad_alloc();
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return *__res;
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}
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_LIBCPP_END_NAMESPACE_STD
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#endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
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_LIBCPP_POP_MACROS
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#endif // _LIBCPP___ALGORITHM_PSTL_COUNT_H
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