|
| 1 | +// -*- C++ -*- |
| 2 | +//===----------------------------------------------------------------------===// |
| 3 | +// |
| 4 | +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 5 | +// See https://llvm.org/LICENSE.txt for license information. |
| 6 | +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 7 | +// |
| 8 | +// Kokkos v. 4.0 |
| 9 | +// Copyright (2022) National Technology & Engineering |
| 10 | +// Solutions of Sandia, LLC (NTESS). |
| 11 | +// |
| 12 | +// Under the terms of Contract DE-NA0003525 with NTESS, |
| 13 | +// the U.S. Government retains certain rights in this software. |
| 14 | +// |
| 15 | +//===---------------------------------------------------------------------===// |
| 16 | + |
| 17 | +#ifndef _LIBCPP___MDSPAN_LAYOUT_LEFT_H |
| 18 | +#define _LIBCPP___MDSPAN_LAYOUT_LEFT_H |
| 19 | + |
| 20 | +#include <__assert> |
| 21 | +#include <__config> |
| 22 | +#include <__fwd/mdspan.h> |
| 23 | +#include <__mdspan/extents.h> |
| 24 | +#include <__type_traits/is_constructible.h> |
| 25 | +#include <__type_traits/is_convertible.h> |
| 26 | +#include <__type_traits/is_nothrow_constructible.h> |
| 27 | +#include <__utility/integer_sequence.h> |
| 28 | +#include <array> |
| 29 | +#include <cinttypes> |
| 30 | +#include <cstddef> |
| 31 | +#include <limits> |
| 32 | + |
| 33 | +#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| 34 | +# pragma GCC system_header |
| 35 | +#endif |
| 36 | + |
| 37 | +_LIBCPP_PUSH_MACROS |
| 38 | +#include <__undef_macros> |
| 39 | + |
| 40 | +_LIBCPP_BEGIN_NAMESPACE_STD |
| 41 | + |
| 42 | +#if _LIBCPP_STD_VER >= 23 |
| 43 | + |
| 44 | +template <class _Extents> |
| 45 | +class layout_left::mapping { |
| 46 | +public: |
| 47 | + static_assert(__mdspan_detail::__is_extents<_Extents>::value, |
| 48 | + "layout_left::mapping template argument must be a specialization of extents."); |
| 49 | + |
| 50 | + using extents_type = _Extents; |
| 51 | + using index_type = typename extents_type::index_type; |
| 52 | + using size_type = typename extents_type::size_type; |
| 53 | + using rank_type = typename extents_type::rank_type; |
| 54 | + using layout_type = layout_left; |
| 55 | + |
| 56 | +private: |
| 57 | + _LIBCPP_HIDE_FROM_ABI static constexpr bool __required_span_size_is_representable(const extents_type& __ext) { |
| 58 | + if constexpr (extents_type::rank() == 0) |
| 59 | + return true; |
| 60 | + |
| 61 | + index_type __prod = __ext.extent(0); |
| 62 | + for (rank_type __r = 1; __r < extents_type::rank(); __r++) { |
| 63 | + bool __overflowed = __builtin_mul_overflow(__prod, __ext.extent(__r), &__prod); |
| 64 | + if (__overflowed) |
| 65 | + return false; |
| 66 | + } |
| 67 | + return true; |
| 68 | + } |
| 69 | + |
| 70 | + static_assert((extents_type::rank_dynamic() > 0) || __required_span_size_is_representable(extents_type()), |
| 71 | + "layout_left::mapping product of static extents must be representable as index_type."); |
| 72 | + |
| 73 | +public: |
| 74 | + // [mdspan.layout.left.cons], constructors |
| 75 | + _LIBCPP_HIDE_FROM_ABI constexpr mapping() noexcept = default; |
| 76 | + _LIBCPP_HIDE_FROM_ABI constexpr mapping(const mapping&) noexcept = default; |
| 77 | + _LIBCPP_HIDE_FROM_ABI constexpr mapping(const extents_type& __ext) noexcept : __extents_(__ext) { |
| 78 | + _LIBCPP_ASSERT(__required_span_size_is_representable(__ext), |
| 79 | + "layout_left::mapping extents ctor: product of extents must be representable as index_type."); |
| 80 | + } |
| 81 | + |
| 82 | + template <class _OtherExtents> |
| 83 | + requires(is_constructible_v<extents_type, _OtherExtents>) |
| 84 | + _LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_OtherExtents, extents_type>) |
| 85 | + mapping(const mapping<_OtherExtents>& __other) noexcept |
| 86 | + : __extents_(__other.extents()) { |
| 87 | + _LIBCPP_ASSERT( |
| 88 | + __mdspan_detail::__is_representable_as<index_type>(__other.required_span_size()), |
| 89 | + "layout_left::mapping converting ctor: other.required_span_size() must be representable as index_type."); |
| 90 | + } |
| 91 | + |
| 92 | + template <class _OtherExtents> |
| 93 | + requires(is_constructible_v<extents_type, _OtherExtents> && _OtherExtents::rank() <= 1) |
| 94 | + _LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_OtherExtents, extents_type>) |
| 95 | + mapping(const layout_right::mapping<_OtherExtents>& __other) noexcept |
| 96 | + : __extents_(__other.extents()) { |
| 97 | + _LIBCPP_ASSERT( |
| 98 | + __mdspan_detail::__is_representable_as<index_type>(__other.required_span_size()), |
| 99 | + "layout_left::mapping converting ctor: other.required_span_size() must be representable as index_type."); |
| 100 | + } |
| 101 | + |
| 102 | +// FIXME: add when we add other layouts |
| 103 | +# if 0 |
| 104 | + template<class _OtherExtents> |
| 105 | + constexpr explicit(extents_type::rank() > 0) |
| 106 | + mapping(const layout_stride::mapping_<OtherExtents>&) noexcept; |
| 107 | +# endif |
| 108 | + |
| 109 | + _LIBCPP_HIDE_FROM_ABI constexpr mapping& operator=(const mapping&) noexcept = default; |
| 110 | + |
| 111 | + // [mdspan.layout.left.obs], observers |
| 112 | + _LIBCPP_HIDE_FROM_ABI constexpr const extents_type& extents() const noexcept { return __extents_; } |
| 113 | + |
| 114 | + _LIBCPP_HIDE_FROM_ABI constexpr index_type required_span_size() const noexcept { |
| 115 | + index_type __size = 1; |
| 116 | + for (size_t __r = 0; __r < extents_type::rank(); __r++) |
| 117 | + __size *= __extents_.extent(__r); |
| 118 | + return __size; |
| 119 | + } |
| 120 | + |
| 121 | + template <class... _Indices> |
| 122 | + requires((sizeof...(_Indices) == extents_type::rank()) && (is_convertible_v<_Indices, index_type> && ...) && |
| 123 | + (is_nothrow_constructible_v<index_type, _Indices> && ...)) |
| 124 | + _LIBCPP_HIDE_FROM_ABI constexpr index_type operator()(_Indices... __idx) const noexcept { |
| 125 | + _LIBCPP_ASSERT(__mdspan_detail::__is_multidimensional_index_in(__extents_, __idx...), |
| 126 | + "layout_left::mapping: out of bounds indexing"); |
| 127 | + array<index_type, extents_type::rank()> __idx_a{static_cast<index_type>(__idx)...}; |
| 128 | + return [&]<size_t... _Pos>(index_sequence<_Pos...>) { |
| 129 | + index_type __res = 0; |
| 130 | + ((__res = __idx_a[extents_type::rank() - 1 - _Pos] + __extents_.extent(extents_type::rank() - 1 - _Pos) * __res), |
| 131 | + ...); |
| 132 | + return __res; |
| 133 | + }(make_index_sequence<sizeof...(_Indices)>()); |
| 134 | + } |
| 135 | + |
| 136 | + _LIBCPP_HIDE_FROM_ABI static constexpr bool is_always_unique() noexcept { return true; } |
| 137 | + _LIBCPP_HIDE_FROM_ABI static constexpr bool is_always_exhaustive() noexcept { return true; } |
| 138 | + _LIBCPP_HIDE_FROM_ABI static constexpr bool is_always_strided() noexcept { return true; } |
| 139 | + |
| 140 | + _LIBCPP_HIDE_FROM_ABI static constexpr bool is_unique() noexcept { return true; } |
| 141 | + _LIBCPP_HIDE_FROM_ABI static constexpr bool is_exhaustive() noexcept { return true; } |
| 142 | + _LIBCPP_HIDE_FROM_ABI static constexpr bool is_strided() noexcept { return true; } |
| 143 | + |
| 144 | + _LIBCPP_HIDE_FROM_ABI constexpr index_type stride(rank_type __r) const noexcept |
| 145 | + requires(extents_type::rank() > 0) |
| 146 | + { |
| 147 | + _LIBCPP_ASSERT(__r < extents_type::rank(), "layout_left::mapping::stride(): invalid rank index"); |
| 148 | + index_type __s = 1; |
| 149 | + for (rank_type __i = extents_type::rank() - 1; __i > __r; __i--) |
| 150 | + __s *= __extents_.extent(__i); |
| 151 | + return __s; |
| 152 | + } |
| 153 | + |
| 154 | + template <class _OtherExtents> |
| 155 | + requires(_OtherExtents::rank() == extents_type::rank()) |
| 156 | + _LIBCPP_HIDE_FROM_ABI friend constexpr bool |
| 157 | + operator==(const mapping& __lhs, const mapping<_OtherExtents>& __rhs) noexcept { |
| 158 | + return __lhs.extents() == __rhs.extents(); |
| 159 | + } |
| 160 | + |
| 161 | +private: |
| 162 | + extents_type __extents_{}; // exposition only |
| 163 | +}; |
| 164 | + |
| 165 | +#endif // _LIBCPP_STD_VER >= 23 |
| 166 | + |
| 167 | +_LIBCPP_END_NAMESPACE_STD |
| 168 | + |
| 169 | +_LIBCPP_POP_MACROS |
| 170 | + |
| 171 | +#endif // _LIBCPP___MDSPAN_LAYOUT_LEFT_H |
0 commit comments