1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
|
//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
// <mdspan>
// Test default iteration:
//
// template<class... Indices>
// constexpr index_type operator()(Indices...) const noexcept;
//
// Constraints:
// * sizeof...(Indices) == extents_type::rank() is true,
// * (is_convertible_v<Indices, index_type> && ...) is true, and
// * (is_nothrow_constructible_v<index_type, Indices> && ...) is true.
//
// Preconditions:
// * extents_type::index-cast(i) is a multidimensional index in extents_.
#include <mdspan>
#include <cassert>
#include <cstdint>
#include "test_macros.h"
#include "../ConvertibleToIntegral.h"
template <class Mapping, class... Indices>
concept operator_constraints = requires(Mapping m, Indices... idxs) {
{ std::is_same_v<decltype(m(idxs...)), typename Mapping::index_type> };
};
template <class Mapping, class... Indices>
requires(operator_constraints<Mapping, Indices...>)
constexpr bool check_operator_constraints(Mapping m, Indices... idxs) {
(void)m(idxs...);
return true;
}
template <class Mapping, class... Indices>
constexpr bool check_operator_constraints(Mapping, Indices...) {
return false;
}
template <class M, class... Args>
constexpr void iterate_stride(M m, const std::array<int, M::extents_type::rank()>& strides, Args... args) {
constexpr int r = static_cast<int>(M::extents_type::rank()) - 1 - static_cast<int>(sizeof...(Args));
if constexpr (-1 == r) {
ASSERT_NOEXCEPT(m(args...));
std::size_t expected_val = static_cast<std::size_t>([&]<std::size_t... Pos>(std::index_sequence<Pos...>) {
return ((args * strides[Pos]) + ... + 0);
}(std::make_index_sequence<M::extents_type::rank()>()));
assert(expected_val == static_cast<std::size_t>(m(args...)));
} else {
for (typename M::index_type i = 0; i < m.extents().extent(r); i++) {
iterate_stride(m, strides, i, args...);
}
}
}
template <class E, class... Args>
constexpr void test_iteration(std::array<int, E::rank()> strides, Args... args) {
using M = std::layout_stride::mapping<E>;
M m(E(args...), strides);
iterate_stride(m, strides);
}
constexpr bool test() {
constexpr std::size_t D = std::dynamic_extent;
test_iteration<std::extents<int>>(std::array<int, 0>{});
test_iteration<std::extents<unsigned, D>>(std::array<int, 1>{2}, 1);
test_iteration<std::extents<unsigned, D>>(std::array<int, 1>{3}, 7);
test_iteration<std::extents<unsigned, 7>>(std::array<int, 1>{4});
test_iteration<std::extents<unsigned, 7, 8>>(std::array<int, 2>{25, 3});
test_iteration<std::extents<signed char, D, D, D, D>>(std::array<int, 4>{1, 1, 1, 1}, 1, 1, 1, 1);
// Check operator constraint for number of arguments
static_assert(check_operator_constraints(
std::layout_stride::mapping<std::extents<int, D>>(std::extents<int, D>(1), std::array{1}), 0));
static_assert(!check_operator_constraints(
std::layout_stride::mapping<std::extents<int, D>>(std::extents<int, D>(1), std::array{1}), 0, 0));
// Check operator constraint for convertibility of arguments to index_type
static_assert(check_operator_constraints(
std::layout_stride::mapping<std::extents<int, D>>(std::extents<int, D>(1), std::array{1}), IntType(0)));
static_assert(!check_operator_constraints(
std::layout_stride::mapping<std::extents<unsigned, D>>(std::extents<unsigned, D>(1), std::array{1}), IntType(0)));
// Check operator constraint for no-throw-constructibility of index_type from arguments
static_assert(!check_operator_constraints(
std::layout_stride::mapping<std::extents<unsigned char, D>>(std::extents<unsigned char, D>(1), std::array{1}),
IntType(0)));
return true;
}
constexpr bool test_large() {
constexpr std::size_t D = std::dynamic_extent;
test_iteration<std::extents<int64_t, D, 8, D, D>>(std::array<int, 4>{2000, 2, 20, 200}, 7, 9, 10);
test_iteration<std::extents<int64_t, D, 8, 1, D>>(std::array<int, 4>{2000, 20, 20, 200}, 7, 10);
return true;
}
int main(int, char**) {
test();
static_assert(test());
// The large test iterates over ~10k loop indices.
// With assertions enabled this triggered the maximum default limit
// for steps in consteval expressions. Assertions roughly double the
// total number of instructions, so this was already close to the maximum.
test_large();
return 0;
}
|
