experimental/__simd/reference.h

0001 // -*- C++ -*-
0002 //===----------------------------------------------------------------------===//
0003 //
0004 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0005 // See https://llvm.org/LICENSE.txt for license information.
0006 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0007 //
0008 //===----------------------------------------------------------------------===//
0009
0010 #ifndef _LIBCPP___CXX03_EXPERIMENTAL___SIMD_REFERENCE_H
0011 #define _LIBCPP___CXX03_EXPERIMENTAL___SIMD_REFERENCE_H
0012
0013 #include <__cxx03/__type_traits/is_assignable.h>
0014 #include <__cxx03/__type_traits/is_same.h>
0015 #include <__cxx03/__utility/forward.h>
0016 #include <__cxx03/__utility/move.h>
0017 #include <__cxx03/cstddef>
0018 #include <__cxx03/experimental/__config>
0019 #include <__cxx03/experimental/__simd/utility.h>
0020
0021 _LIBCPP_PUSH_MACROS
0022 #include <__cxx03/__undef_macros>
0023
0024 #if _LIBCPP_STD_VER >= 17 && defined(_LIBCPP_ENABLE_EXPERIMENTAL)
0025
0026 _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL
0027 inline namespace parallelism_v2 {
0028 template <class _Tp, class _Storage, class _Vp>
0029 class __simd_reference {
0030   template <class, class>
0031   friend class simd;
0032   template <class, class>
0033   friend class simd_mask;
0034
0035   _Storage& __s_;
0036   size_t __idx_;
0037
0038   _LIBCPP_HIDE_FROM_ABI __simd_reference(_Storage& __s, size_t __idx) : __s_(__s), __idx_(__idx) {}
0039
0040   _LIBCPP_HIDE_FROM_ABI _Vp __get() const noexcept { return __s_.__get(__idx_); }
0041
0042   _LIBCPP_HIDE_FROM_ABI void __set(_Vp __v) {
0043     if constexpr (is_same_v<_Vp, bool>)
0044       __s_.__set(__idx_, experimental::__set_all_bits<_Tp>(__v));
0045     else
0046       __s_.__set(__idx_, __v);
0047   }
0048
0049 public:
0050   using value_type = _Vp;
0051
0052   __simd_reference()                        = delete;
0053   __simd_reference(const __simd_reference&) = delete;
0054
0055   _LIBCPP_HIDE_FROM_ABI operator value_type() const noexcept { return __get(); }
0056
0057   template <class _Up, enable_if_t<is_assignable_v<value_type&, _Up&&>, int> = 0>
0058   _LIBCPP_HIDE_FROM_ABI __simd_reference operator=(_Up&& __v) && noexcept {
0059     __set(static_cast<value_type>(std::forward<_Up>(__v)));
0060     return {__s_, __idx_};
0061   }
0062
0063   // Note: This approach might not fully align with the specification,
0064   // which might be a wording defect. (https://wg21.link/N4808 section 9.6.3)
0065   template <class _Tp1, class _Storage1, class _Vp1>
0066   friend void
0067   swap(__simd_reference<_Tp1, _Storage1, _Vp1>&& __a, __simd_reference<_Tp1, _Storage1, _Vp1>&& __b) noexcept;
0068
0069   template <class _Tp1, class _Storage1, class _Vp1>
0070   friend void swap(_Vp1& __a, __simd_reference<_Tp1, _Storage1, _Vp1>&& __b) noexcept;
0071
0072   template <class _Tp1, class _Storage1, class _Vp1>
0073   friend void swap(__simd_reference<_Tp1, _Storage1, _Vp1>&& __a, _Vp1& __b) noexcept;
0074 };
0075
0076 template <class _Tp, class _Storage, class _Vp>
0077 _LIBCPP_HIDE_FROM_ABI void
0078 swap(__simd_reference<_Tp, _Storage, _Vp>&& __a, __simd_reference<_Tp, _Storage, _Vp>&& __b) noexcept {
0079   _Vp __tmp(std::move(__a));
0080   std::move(__a) = std::move(__b);
0081   std::move(__b) = std::move(__tmp);
0082 }
0083
0084 template <class _Tp, class _Storage, class _Vp>
0085 _LIBCPP_HIDE_FROM_ABI void swap(_Vp& __a, __simd_reference<_Tp, _Storage, _Vp>&& __b) noexcept {
0086   _Vp __tmp(std::move(__a));
0087   __a            = std::move(__b);
0088   std::move(__b) = std::move(__tmp);
0089 }
0090
0091 template <class _Tp, class _Storage, class _Vp>
0092 _LIBCPP_HIDE_FROM_ABI void swap(__simd_reference<_Tp, _Storage, _Vp>&& __a, _Vp& __b) noexcept {
0093   _Vp __tmp(std::move(__a));
0094   std::move(__a) = std::move(__b);
0095   __b            = std::move(__tmp);
0096 }
0097
0098 } // namespace parallelism_v2
0099 _LIBCPP_END_NAMESPACE_EXPERIMENTAL
0100
0101 #endif // _LIBCPP_STD_VER >= 17 && defined(_LIBCPP_ENABLE_EXPERIMENTAL)
0102
0103 _LIBCPP_POP_MACROS
0104
0105 #endif // _LIBCPP___CXX03_EXPERIMENTAL___SIMD_REFERENCE_H