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.
91 lines
3.4 KiB
C++
91 lines
3.4 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_ROTATE_COPY_H
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#define _LIBCPP___ALGORITHM_PSTL_ROTATE_COPY_H
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#include <__algorithm/pstl_copy.h>
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#include <__algorithm/pstl_frontend_dispatch.h>
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#include <__iterator/cpp17_iterator_concepts.h>
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#include <__pstl/configuration.h>
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#include <__type_traits/is_execution_policy.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_rotate_copy();
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template <class _ExecutionPolicy,
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class _ForwardIterator,
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class _ForwardOutIterator,
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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<_ForwardOutIterator>
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__rotate_copy(_ExecutionPolicy&& __policy,
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_ForwardIterator&& __first,
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_ForwardIterator&& __middle,
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_ForwardIterator&& __last,
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_ForwardOutIterator&& __result) noexcept {
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return std::__pstl_frontend_dispatch(
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_LIBCPP_PSTL_CUSTOMIZATION_POINT(__pstl_rotate_copy, _RawPolicy),
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[&__policy](_ForwardIterator __g_first,
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_ForwardIterator __g_middle,
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_ForwardIterator __g_last,
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_ForwardOutIterator __g_result) -> optional<_ForwardOutIterator> {
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auto __result_mid =
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std::__copy(__policy, _ForwardIterator(__g_middle), std::move(__g_last), std::move(__g_result));
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if (!__result_mid)
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return nullopt;
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return std::__copy(__policy, std::move(__g_first), std::move(__g_middle), *std::move(__result_mid));
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},
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std::move(__first),
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std::move(__middle),
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std::move(__last),
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std::move(__result));
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}
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template <class _ExecutionPolicy,
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class _ForwardIterator,
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class _ForwardOutIterator,
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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 _ForwardOutIterator rotate_copy(
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_ExecutionPolicy&& __policy,
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_ForwardIterator __first,
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_ForwardIterator __middle,
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_ForwardIterator __last,
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_ForwardOutIterator __result) {
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_LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator, "rotate_copy requires ForwardIterators");
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_LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardOutIterator, "rotate_copy requires ForwardIterators");
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_LIBCPP_REQUIRE_CPP17_OUTPUT_ITERATOR(
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_ForwardOutIterator, decltype(*__first), "rotate_copy requires an OutputIterator");
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auto __res =
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std::__rotate_copy(__policy, std::move(__first), std::move(__middle), std::move(__last), std::move(__result));
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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_ROTATE_COPY_H
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