llvm-capstone/libcxx/include/execution
Louis Dionne 8e2d09c339 [libc++][PSTL] Add more specialized backend customization points
This allows backends to customize arbitrary parallel algorithms, which was requested pretty often.

Reviewed By: #libc, ldionne

Spies: arichardson, miyuki, crtrott, dalg24, __simt__, philnik, libcxx-commits

Differential Revision: https://reviews.llvm.org/D149686
2023-05-11 13:54:28 -07:00

147 lines
5.1 KiB
C++

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP_EXECUTION
#define _LIBCPP_EXECUTION
/*
namespace std::execution {
struct sequenced_policy;
struct parallel_policy;
struct parallel_unsequenced_policy;
struct unsequenced_policy; // since C++20
inline constexpr sequenced_policy seq = implementation-defined;
inline constexpr parallel_policy par = implementation-defined;
inline constexpr parallel_unsequenced_policy par_unseq = implementation-defined;
inline constexpr unsequenced_policy unseq = implementation-defined; // since C++20
}
namespace std {
template <class T>
struct is_execution_policy;
template <class T>
inline constexpr bool is_execution_policy_v;
}
*/
#include <__assert> // all public C++ headers provide the assertion handler
#include <__config>
#include <__type_traits/is_execution_policy.h>
#include <__type_traits/is_same.h>
#include <__type_traits/remove_cvref.h>
#include <version>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
#if !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
_LIBCPP_BEGIN_NAMESPACE_STD
namespace execution {
struct sequenced_policy {
_LIBCPP_HIDE_FROM_ABI constexpr explicit sequenced_policy(__disable_user_instantiations_tag) {}
sequenced_policy(const sequenced_policy&) = delete;
sequenced_policy& operator=(const sequenced_policy&) = delete;
};
inline constexpr sequenced_policy seq{__disable_user_instantiations_tag{}};
struct parallel_policy {
_LIBCPP_HIDE_FROM_ABI constexpr explicit parallel_policy(__disable_user_instantiations_tag) {}
parallel_policy(const parallel_policy&) = delete;
parallel_policy& operator=(const parallel_policy&) = delete;
};
inline constexpr parallel_policy par{__disable_user_instantiations_tag{}};
struct parallel_unsequenced_policy {
_LIBCPP_HIDE_FROM_ABI constexpr explicit parallel_unsequenced_policy(__disable_user_instantiations_tag) {}
parallel_unsequenced_policy(const parallel_unsequenced_policy&) = delete;
parallel_unsequenced_policy& operator=(const parallel_unsequenced_policy&) = delete;
};
inline constexpr parallel_unsequenced_policy par_unseq{__disable_user_instantiations_tag{}};
struct __unsequenced_policy {
_LIBCPP_HIDE_FROM_ABI constexpr explicit __unsequenced_policy(__disable_user_instantiations_tag) {}
__unsequenced_policy(const __unsequenced_policy&) = delete;
__unsequenced_policy& operator=(const __unsequenced_policy&) = delete;
};
constexpr __unsequenced_policy __unseq{__disable_user_instantiations_tag{}};
# if _LIBCPP_STD_VER >= 20
struct unsequenced_policy {
_LIBCPP_HIDE_FROM_ABI constexpr explicit unsequenced_policy(__disable_user_instantiations_tag) {}
unsequenced_policy(const unsequenced_policy&) = delete;
unsequenced_policy& operator=(const unsequenced_policy&) = delete;
};
inline constexpr unsequenced_policy unseq{__disable_user_instantiations_tag{}};
# endif // _LIBCPP_STD_VER >= 20
} // namespace execution
template <>
inline constexpr bool is_execution_policy_v<execution::sequenced_policy> = true;
template <>
inline constexpr bool is_execution_policy_v<execution::parallel_policy> = true;
template <>
inline constexpr bool is_execution_policy_v<execution::parallel_unsequenced_policy> = true;
template <>
inline constexpr bool is_execution_policy_v<execution::__unsequenced_policy> = true;
template <>
inline constexpr bool __is_parallel_execution_policy_impl<execution::parallel_policy> = true;
template <>
inline constexpr bool __is_parallel_execution_policy_impl<execution::parallel_unsequenced_policy> = true;
template <>
inline constexpr bool __is_unsequenced_execution_policy_impl<execution::__unsequenced_policy> = true;
template <>
inline constexpr bool __is_unsequenced_execution_policy_impl<execution::parallel_unsequenced_policy> = true;
# if _LIBCPP_STD_VER >= 20
template <>
inline constexpr bool is_execution_policy_v<execution::unsequenced_policy> = true;
template <>
inline constexpr bool __is_unsequenced_execution_policy_impl<execution::unsequenced_policy> = true;
# endif
template <class _Tp>
struct is_execution_policy : bool_constant<is_execution_policy_v<_Tp>> {};
template <class _ExecutionPolicy>
_LIBCPP_HIDE_FROM_ABI auto __remove_parallel_policy(const _ExecutionPolicy&) {
if constexpr (is_same_v<_ExecutionPolicy, execution::parallel_policy>) {
return execution::sequenced_policy(execution::__disable_user_instantiations_tag{});
} else if constexpr (is_same_v<_ExecutionPolicy, execution::parallel_unsequenced_policy>) {
return execution::__unsequenced_policy{execution::__disable_user_instantiations_tag{}};
}
}
_LIBCPP_END_NAMESPACE_STD
#endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
#endif // _LIBCPP_EXECUTION