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a945c346 | 1 | // Copyright (C) 2018-2024 Free Software Foundation, Inc. |
9866abe3 JW |
2 | // |
3 | // This file is part of the GNU ISO C++ Library. This library is free | |
4 | // software; you can redistribute it and/or modify it under the | |
5 | // terms of the GNU General Public License as published by the | |
6 | // Free Software Foundation; either version 3, or (at your option) | |
7 | // any later version. | |
8 | ||
9 | // This library is distributed in the hope that it will be useful, | |
10 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | // GNU General Public License for more details. | |
13 | ||
14 | // You should have received a copy of the GNU General Public License along | |
15 | // with this library; see the file COPYING3. If not see | |
16 | // <http://www.gnu.org/licenses/>. | |
17 | ||
8ccae163 | 18 | // { dg-do compile { target c++20 } } |
9866abe3 JW |
19 | |
20 | #include <bit> | |
21 | #include <limits> | |
22 | ||
23 | template<typename UInt> | |
24 | constexpr auto | |
25 | test(UInt x) | |
26 | -> decltype(std::has_single_bit(x)) | |
27 | { | |
28 | static_assert( noexcept(std::has_single_bit(x)) ); | |
29 | ||
30 | static_assert( ! std::has_single_bit( (UInt)0 ) ); | |
31 | static_assert( ! std::has_single_bit( (UInt)-1 ) ); | |
32 | static_assert( ! std::has_single_bit( (UInt)3 ) ); | |
33 | static_assert( ! std::has_single_bit( (UInt)0x0f ) ); | |
34 | static_assert( ! std::has_single_bit( (UInt)0xff ) ); | |
35 | static_assert( ! std::has_single_bit( (UInt)0x0a ) ); | |
36 | static_assert( ! std::has_single_bit( (UInt)0xa0 ) ); | |
37 | ||
38 | constexpr UInt one = 1; | |
39 | static_assert( std::has_single_bit( (UInt)(one << 0) ) ); | |
40 | ||
41 | static_assert( std::has_single_bit( (UInt)(one << 1) ) ); | |
42 | static_assert( std::has_single_bit( (UInt)(one << 2) ) ); | |
43 | static_assert( std::has_single_bit( (UInt)(one << 3) ) ); | |
44 | static_assert( std::has_single_bit( (UInt)(one << 4) ) ); | |
45 | static_assert( std::has_single_bit( (UInt)(one << 5) ) ); | |
46 | static_assert( std::has_single_bit( (UInt)(one << 6) ) ); | |
47 | static_assert( std::has_single_bit( (UInt)(one << 7) ) ); | |
48 | ||
49 | if constexpr (std::numeric_limits<UInt>::digits > 8) | |
50 | { | |
51 | static_assert( std::has_single_bit( (UInt)(one << 8) ) ); | |
52 | static_assert( std::has_single_bit( (UInt)(one << 9) ) ); | |
53 | static_assert( std::has_single_bit( (UInt)(one << 10) ) ); | |
54 | static_assert( std::has_single_bit( (UInt)(one << 11) ) ); | |
55 | static_assert( std::has_single_bit( (UInt)(one << 12) ) ); | |
56 | static_assert( std::has_single_bit( (UInt)(one << 13) ) ); | |
57 | static_assert( std::has_single_bit( (UInt)(one << 14) ) ); | |
58 | static_assert( std::has_single_bit( (UInt)(one << 15) ) ); | |
59 | ||
60 | static_assert( ! std::has_single_bit( (UInt)0xf000 ) ); | |
61 | static_assert( ! std::has_single_bit( (UInt)0xff00 ) ); | |
62 | static_assert( ! std::has_single_bit( (UInt)0xf0f0 ) ); | |
63 | static_assert( ! std::has_single_bit( (UInt)0xf00f ) ); | |
64 | static_assert( ! std::has_single_bit( (UInt)0x0f0f ) ); | |
65 | static_assert( ! std::has_single_bit( (UInt)0x00ff ) ); | |
66 | } | |
67 | ||
68 | if constexpr (std::numeric_limits<UInt>::digits > 16) | |
69 | { | |
70 | static_assert( std::has_single_bit( (UInt)(one << 16) ) ); | |
71 | static_assert( std::has_single_bit( (UInt)(one << 17) ) ); | |
72 | static_assert( ! std::has_single_bit( (UInt)((one << 16) + 1) ) ); | |
73 | static_assert( ! std::has_single_bit( (UInt)((one << 16) + 0x10) ) ); | |
74 | } | |
75 | ||
76 | // msp340 target has 20-bit __GLIBCXX_TYPE_INT_N_0 type | |
77 | if constexpr (std::numeric_limits<UInt>::digits > 20) | |
78 | { | |
79 | static_assert( std::has_single_bit( (UInt)(one << 20) ) ); | |
80 | static_assert( std::has_single_bit( (UInt)(one << 21) ) ); | |
81 | static_assert( std::has_single_bit( (UInt)(one << 24) ) ); | |
82 | static_assert( std::has_single_bit( (UInt)(one << 28) ) ); | |
83 | static_assert( std::has_single_bit( (UInt)(one << 31) ) ); | |
84 | } | |
85 | ||
86 | if constexpr (std::numeric_limits<UInt>::digits > 32) | |
87 | { | |
88 | static_assert( std::has_single_bit( (UInt)(one << 32) ) ); | |
89 | static_assert( std::has_single_bit( (UInt)(one << 33) ) ); | |
90 | static_assert( std::has_single_bit( (UInt)(one << 41) ) ); | |
91 | ||
92 | static_assert( ! std::has_single_bit( (UInt)((one << 32) + 1) ) ); | |
93 | static_assert( ! std::has_single_bit( (UInt)((one << 32) + (one << 31)) ) ); | |
94 | static_assert( ! std::has_single_bit( (UInt)((one << 33) + 1) ) ); | |
95 | static_assert( ! std::has_single_bit( (UInt)((one << 33) + (one << 32)) ) ); | |
96 | } | |
97 | ||
98 | if constexpr (std::numeric_limits<UInt>::digits == 64) | |
99 | { | |
100 | static_assert( std::has_single_bit( (UInt)(one << 63) ) ); | |
101 | ||
102 | static_assert( ! std::has_single_bit( (UInt)((one << 63) + 1) ) ); | |
103 | static_assert( ! std::has_single_bit( (UInt)((one << 63) + (one << 8)) ) ); | |
104 | static_assert( ! std::has_single_bit( (UInt)((one << 63) + (one << 32)) ) ); | |
105 | } | |
106 | return true; | |
107 | } | |
108 | ||
109 | static_assert( test( (unsigned char)0 ) ); | |
110 | static_assert( test( (unsigned short)0 ) ); | |
111 | static_assert( test( (unsigned int)0 ) ); | |
112 | static_assert( test( (unsigned long)0 ) ); | |
113 | static_assert( test( (unsigned long long)0 ) ); | |
114 | ||
115 | // std::has_single_bit(T) shall not participate in overload resolution | |
116 | // unless T is an unsigned integer type. | |
117 | struct X { constexpr bool did_not_match() { return true; } }; | |
118 | constexpr X test(...) { return X{}; } | |
119 | static_assert( test( (bool)0 ).did_not_match() ); | |
120 | static_assert( test( (char)0 ).did_not_match() ); | |
121 | static_assert( test( (int)0 ).did_not_match() ); | |
122 | static_assert( test( (char16_t)0 ).did_not_match() ); | |
123 | static_assert( test( (float)0 ).did_not_match() ); | |
124 | static_assert( test( (void*)0 ).did_not_match() ); | |
125 | static_assert( test( X{} ).did_not_match() ); | |
126 | enum E : unsigned { e }; | |
127 | static_assert( test( e ).did_not_match() ); | |
128 | ||
29a9de9b | 129 | #if !defined(__STRICT_ANSI__) && defined __SIZEOF_INT128__ |
9866abe3 JW |
130 | static_assert( test( (unsigned __int128)0 ) ); |
131 | static_assert( test( (__int128)0 ).did_not_match() ); | |
132 | #endif | |
133 | #if defined(__GLIBCXX_TYPE_INT_N_0) | |
134 | static_assert( test( (unsigned __GLIBCXX_TYPE_INT_N_0)0 ) ); | |
135 | static_assert( test( (__GLIBCXX_TYPE_INT_N_0)0 ).did_not_match() ); | |
136 | #endif | |
137 | #if defined(__GLIBCXX_TYPE_INT_N_1) | |
138 | static_assert( test( (unsigned __GLIBCXX_TYPE_INT_N_1)0 ) ); | |
139 | static_assert( test( (__GLIBCXX_TYPE_INT_N_1)0 ).did_not_match() ); | |
140 | #endif | |
141 | #if defined(__GLIBCXX_TYPE_INT_N_2) | |
142 | static_assert( test( (unsigned __GLIBCXX_TYPE_INT_N_2)0 ) ); | |
143 | static_assert( test( (__GLIBCXX_TYPE_INT_N_2)0 ).did_not_match() ); | |
144 | #endif | |
29a9de9b JW |
145 | #if defined(__GLIBCXX_TYPE_INT_N_3) |
146 | static_assert( test( (unsigned __GLIBCXX_TYPE_INT_N_3)0 ) ); | |
147 | static_assert( test( (__GLIBCXX_TYPE_INT_N_3)0 ).did_not_match() ); | |
148 | #endif | |
9866abe3 JW |
149 | |
150 | #include <cstddef> | |
151 | static_assert( test( (std::byte)0 ).did_not_match() ); |