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 // Constraints: T is an unsigned integer type
15 // Returns: The number of bits set to one in the value of x.
16
17 #include <bit>
18 #include <cassert>
19 #include <cstdint>
20 #include <type_traits>
21
22 #include "test_macros.h"
23
24 struct A {};
25 enum E1 : unsigned char { rEd };
26 enum class E2 : unsigned char { red };
27
28 template <class T>
test()29 constexpr bool test()
30 {
31 ASSERT_SAME_TYPE(decltype(std::popcount(T())), int);
32 ASSERT_NOEXCEPT(std::popcount(T()));
33 T max = std::numeric_limits<T>::max();
34
35 assert(std::popcount(T(0)) == 0);
36 assert(std::popcount(T(1)) == 1);
37 assert(std::popcount(T(2)) == 1);
38 assert(std::popcount(T(3)) == 2);
39 assert(std::popcount(T(4)) == 1);
40 assert(std::popcount(T(5)) == 2);
41 assert(std::popcount(T(6)) == 2);
42 assert(std::popcount(T(7)) == 3);
43 assert(std::popcount(T(8)) == 1);
44 assert(std::popcount(T(9)) == 2);
45 assert(std::popcount(T(121)) == 5);
46 assert(std::popcount(T(127)) == 7);
47 assert(std::popcount(T(128)) == 1);
48 assert(std::popcount(T(130)) == 2);
49 assert(std::popcount(T(max >> 1)) == std::numeric_limits<T>::digits - 1);
50 assert(std::popcount(T(max - 1)) == std::numeric_limits<T>::digits - 1);
51 assert(std::popcount(max) == std::numeric_limits<T>::digits);
52
53 #ifndef TEST_HAS_NO_INT128
54 if constexpr (std::is_same_v<T, __uint128_t>) {
55 T val = 128;
56 assert(std::popcount(val-1) == 7);
57 assert(std::popcount(val) == 1);
58 assert(std::popcount(val+1) == 2);
59 val <<= 32;
60 assert(std::popcount(val-1) == 39);
61 assert(std::popcount(val) == 1);
62 assert(std::popcount(val+1) == 2);
63 val <<= 60;
64 assert(std::popcount(val-1) == 99);
65 assert(std::popcount(val) == 1);
66 assert(std::popcount(val+1) == 2);
67
68 T x = T(1) << 63;
69 T y = T(1) << 64;
70 assert(std::popcount(x) == 1);
71 assert(std::popcount(y) == 1);
72 assert(std::popcount(x+y) == 2);
73 }
74 #endif
75
76 return true;
77 }
78
main(int,char **)79 int main(int, char**)
80 {
81 {
82 auto lambda = [](auto x) -> decltype(std::popcount(x)) {};
83 using L = decltype(lambda);
84
85 static_assert(!std::is_invocable_v<L, signed char>);
86 static_assert(!std::is_invocable_v<L, short>);
87 static_assert(!std::is_invocable_v<L, int>);
88 static_assert(!std::is_invocable_v<L, long>);
89 static_assert(!std::is_invocable_v<L, long long>);
90 #ifndef TEST_HAS_NO_INT128
91 static_assert(!std::is_invocable_v<L, __int128_t>);
92 #endif
93
94 static_assert(!std::is_invocable_v<L, int8_t>);
95 static_assert(!std::is_invocable_v<L, int16_t>);
96 static_assert(!std::is_invocable_v<L, int32_t>);
97 static_assert(!std::is_invocable_v<L, int64_t>);
98 static_assert(!std::is_invocable_v<L, intmax_t>);
99 static_assert(!std::is_invocable_v<L, intptr_t>);
100 static_assert(!std::is_invocable_v<L, ptrdiff_t>);
101
102 static_assert(!std::is_invocable_v<L, bool>);
103 static_assert(!std::is_invocable_v<L, char>);
104 static_assert(!std::is_invocable_v<L, wchar_t>);
105 #ifndef TEST_HAS_NO_CHAR8_T
106 static_assert(!std::is_invocable_v<L, char8_t>);
107 #endif
108 static_assert(!std::is_invocable_v<L, char16_t>);
109 static_assert(!std::is_invocable_v<L, char32_t>);
110
111 static_assert(!std::is_invocable_v<L, A>);
112 static_assert(!std::is_invocable_v<L, A*>);
113 static_assert(!std::is_invocable_v<L, E1>);
114 static_assert(!std::is_invocable_v<L, E2>);
115 }
116
117 static_assert(test<unsigned char>());
118 static_assert(test<unsigned short>());
119 static_assert(test<unsigned int>());
120 static_assert(test<unsigned long>());
121 static_assert(test<unsigned long long>());
122 #ifndef TEST_HAS_NO_INT128
123 static_assert(test<__uint128_t>());
124 #endif
125 static_assert(test<uint8_t>());
126 static_assert(test<uint16_t>());
127 static_assert(test<uint32_t>());
128 static_assert(test<uint64_t>());
129 static_assert(test<uintmax_t>());
130 static_assert(test<uintptr_t>());
131 static_assert(test<size_t>());
132
133 test<unsigned char>();
134 test<unsigned short>();
135 test<unsigned int>();
136 test<unsigned long>();
137 test<unsigned long long>();
138 #ifndef TEST_HAS_NO_INT128
139 test<__uint128_t>();
140 #endif
141 test<uint8_t>();
142 test<uint16_t>();
143 test<uint32_t>();
144 test<uint64_t>();
145 test<uintmax_t>();
146 test<uintptr_t>();
147 test<size_t>();
148
149 return 0;
150 }
151