1 //===----------------------------------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 // UNSUPPORTED: c++03, c++11, c++14, c++17
10
11 // template <class T>
12 // constexpr int popcount(T x) noexcept;
13
14 // Returns: The number of bits set to one in the value of x.
15 //
16 // Remarks: This function shall not participate in overload resolution unless
17 // T is an unsigned integer type
18
19 #include <bit>
20 #include <cstdint>
21 #include <type_traits>
22 #include <cassert>
23
24 #include "test_macros.h"
25
26 class A{};
27 enum E1 : unsigned char { rEd };
28 enum class E2 : unsigned char { red };
29
30 template <typename T>
constexpr_test()31 constexpr bool constexpr_test()
32 {
33 return std::popcount(T(0)) == 0
34 && std::popcount(T(1)) == 1
35 && std::popcount(T(2)) == 1
36 && std::popcount(T(3)) == 2
37 && std::popcount(T(4)) == 1
38 && std::popcount(T(5)) == 2
39 && std::popcount(T(6)) == 2
40 && std::popcount(T(7)) == 3
41 && std::popcount(T(8)) == 1
42 && std::popcount(T(9)) == 2
43 && std::popcount(std::numeric_limits<T>::max()) == std::numeric_limits<T>::digits
44 ;
45 }
46
47
48 template <typename T>
runtime_test()49 void runtime_test()
50 {
51 ASSERT_SAME_TYPE(int, decltype(std::popcount(T(0))));
52 ASSERT_NOEXCEPT( std::popcount(T(0)));
53
54 assert( std::popcount(T(121)) == 5);
55 assert( std::popcount(T(122)) == 5);
56 assert( std::popcount(T(123)) == 6);
57 assert( std::popcount(T(124)) == 5);
58 assert( std::popcount(T(125)) == 6);
59 assert( std::popcount(T(126)) == 6);
60 assert( std::popcount(T(127)) == 7);
61 assert( std::popcount(T(128)) == 1);
62 assert( std::popcount(T(129)) == 2);
63 assert( std::popcount(T(130)) == 2);
64 }
65
main(int,char **)66 int main(int, char**)
67 {
68
69 {
70 auto lambda = [](auto x) -> decltype(std::popcount(x)) {};
71 using L = decltype(lambda);
72
73 static_assert( std::is_invocable_v<L, unsigned char>, "");
74 static_assert( std::is_invocable_v<L, unsigned int>, "");
75 static_assert( std::is_invocable_v<L, unsigned long>, "");
76 static_assert( std::is_invocable_v<L, unsigned long long>, "");
77
78 static_assert( std::is_invocable_v<L, uint8_t>, "");
79 static_assert( std::is_invocable_v<L, uint16_t>, "");
80 static_assert( std::is_invocable_v<L, uint32_t>, "");
81 static_assert( std::is_invocable_v<L, uint64_t>, "");
82 static_assert( std::is_invocable_v<L, size_t>, "");
83
84 static_assert( std::is_invocable_v<L, uintmax_t>, "");
85 static_assert( std::is_invocable_v<L, uintptr_t>, "");
86
87
88 static_assert(!std::is_invocable_v<L, int>, "");
89 static_assert(!std::is_invocable_v<L, signed int>, "");
90 static_assert(!std::is_invocable_v<L, long>, "");
91 static_assert(!std::is_invocable_v<L, long long>, "");
92
93 static_assert(!std::is_invocable_v<L, int8_t>, "");
94 static_assert(!std::is_invocable_v<L, int16_t>, "");
95 static_assert(!std::is_invocable_v<L, int32_t>, "");
96 static_assert(!std::is_invocable_v<L, int64_t>, "");
97 static_assert(!std::is_invocable_v<L, ptrdiff_t>, "");
98
99 static_assert(!std::is_invocable_v<L, bool>, "");
100 static_assert(!std::is_invocable_v<L, signed char>, "");
101 static_assert(!std::is_invocable_v<L, char16_t>, "");
102 static_assert(!std::is_invocable_v<L, char32_t>, "");
103
104 #ifndef _LIBCPP_HAS_NO_INT128
105 static_assert( std::is_invocable_v<L, __uint128_t>, "");
106 static_assert(!std::is_invocable_v<L, __int128_t>, "");
107 #endif
108
109 static_assert(!std::is_invocable_v<L, A>, "");
110 static_assert(!std::is_invocable_v<L, E1>, "");
111 static_assert(!std::is_invocable_v<L, E2>, "");
112 }
113
114 static_assert(constexpr_test<unsigned char>(), "");
115 static_assert(constexpr_test<unsigned short>(), "");
116 static_assert(constexpr_test<unsigned>(), "");
117 static_assert(constexpr_test<unsigned long>(), "");
118 static_assert(constexpr_test<unsigned long long>(), "");
119
120 static_assert(constexpr_test<uint8_t>(), "");
121 static_assert(constexpr_test<uint16_t>(), "");
122 static_assert(constexpr_test<uint32_t>(), "");
123 static_assert(constexpr_test<uint64_t>(), "");
124 static_assert(constexpr_test<size_t>(), "");
125 static_assert(constexpr_test<uintmax_t>(), "");
126 static_assert(constexpr_test<uintptr_t>(), "");
127
128 #ifndef _LIBCPP_HAS_NO_INT128
129 static_assert(constexpr_test<__uint128_t>(), "");
130 #endif
131
132
133 runtime_test<unsigned char>();
134 runtime_test<unsigned>();
135 runtime_test<unsigned short>();
136 runtime_test<unsigned long>();
137 runtime_test<unsigned long long>();
138
139 runtime_test<uint8_t>();
140 runtime_test<uint16_t>();
141 runtime_test<uint32_t>();
142 runtime_test<uint64_t>();
143 runtime_test<size_t>();
144 runtime_test<uintmax_t>();
145 runtime_test<uintptr_t>();
146
147 #ifndef _LIBCPP_HAS_NO_INT128
148 runtime_test<__uint128_t>();
149
150 {
151 __uint128_t val = 128;
152
153 val <<= 32;
154 assert( std::popcount(val-1) == 39);
155 assert( std::popcount(val) == 1);
156 assert( std::popcount(val+1) == 2);
157 val <<= 2;
158 assert( std::popcount(val-1) == 41);
159 assert( std::popcount(val) == 1);
160 assert( std::popcount(val+1) == 2);
161 val <<= 3;
162 assert( std::popcount(val-1) == 44);
163 assert( std::popcount(val) == 1);
164 assert( std::popcount(val+1) == 2);
165 }
166 #endif
167
168 return 0;
169 }
170