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 countl_one(T x) noexcept;
13
14 // Constraints: T is an unsigned integer type
15 // The number of consecutive 1 bits, starting from the most significant bit.
16 // [ Note: Returns N if x == std::numeric_limits<T>::max(). ]
17
18 #include <bit>
19 #include <cassert>
20 #include <cstdint>
21 #include <type_traits>
22
23 #include "test_macros.h"
24
25 struct A {};
26 enum E1 : unsigned char { rEd };
27 enum class E2 : unsigned char { red };
28
29 template <class T>
test()30 constexpr bool test()
31 {
32 ASSERT_SAME_TYPE(decltype(std::countl_one(T())), int);
33 ASSERT_NOEXCEPT(std::countl_one(T()));
34 T max = std::numeric_limits<T>::max();
35
36 assert(std::countl_one(T(0)) == 0);
37 assert(std::countl_one(T(1)) == 0);
38 assert(std::countl_one(T(10)) == 0);
39 assert(std::countl_one(T(100)) == 0);
40 assert(std::countl_one(max) == std::numeric_limits<T>::digits);
41 assert(std::countl_one(T(max - 1)) == std::numeric_limits<T>::digits - 1);
42 assert(std::countl_one(T(max - 2)) == std::numeric_limits<T>::digits - 2);
43 assert(std::countl_one(T(max - 3)) == std::numeric_limits<T>::digits - 2);
44 assert(std::countl_one(T(max - 4)) == std::numeric_limits<T>::digits - 3);
45 assert(std::countl_one(T(max - 5)) == std::numeric_limits<T>::digits - 3);
46 assert(std::countl_one(T(max - 6)) == std::numeric_limits<T>::digits - 3);
47 assert(std::countl_one(T(max - 7)) == std::numeric_limits<T>::digits - 3);
48 assert(std::countl_one(T(max - 8)) == std::numeric_limits<T>::digits - 4);
49 assert(std::countl_one(T(max - 9)) == std::numeric_limits<T>::digits - 4);
50 assert(std::countl_one(T(max - 126)) == std::numeric_limits<T>::digits - 7);
51 assert(std::countl_one(T(max - 127)) == std::numeric_limits<T>::digits - 7);
52 assert(std::countl_one(T(max - 128)) == std::numeric_limits<T>::digits - 8);
53
54 #ifndef TEST_HAS_NO_INT128
55 if constexpr (std::is_same_v<T, __uint128_t>) {
56 T val = 128;
57 assert(std::countl_one(~val) == 120);
58 val <<= 32;
59 assert(std::countl_one(~val) == 88);
60 val <<= 60;
61 assert(std::countl_one(~val) == 28);
62 }
63 #endif
64
65 return true;
66 }
67
main(int,char **)68 int main(int, char**)
69 {
70 {
71 auto lambda = [](auto x) -> decltype(std::countl_one(x)) {};
72 using L = decltype(lambda);
73
74 static_assert(!std::is_invocable_v<L, signed char>);
75 static_assert(!std::is_invocable_v<L, short>);
76 static_assert(!std::is_invocable_v<L, int>);
77 static_assert(!std::is_invocable_v<L, long>);
78 static_assert(!std::is_invocable_v<L, long long>);
79 #ifndef TEST_HAS_NO_INT128
80 static_assert(!std::is_invocable_v<L, __int128_t>);
81 #endif
82
83 static_assert(!std::is_invocable_v<L, int8_t>);
84 static_assert(!std::is_invocable_v<L, int16_t>);
85 static_assert(!std::is_invocable_v<L, int32_t>);
86 static_assert(!std::is_invocable_v<L, int64_t>);
87 static_assert(!std::is_invocable_v<L, intmax_t>);
88 static_assert(!std::is_invocable_v<L, intptr_t>);
89 static_assert(!std::is_invocable_v<L, ptrdiff_t>);
90
91 static_assert(!std::is_invocable_v<L, bool>);
92 static_assert(!std::is_invocable_v<L, char>);
93 static_assert(!std::is_invocable_v<L, wchar_t>);
94 #ifndef TEST_HAS_NO_CHAR8_T
95 static_assert(!std::is_invocable_v<L, char8_t>);
96 #endif
97 static_assert(!std::is_invocable_v<L, char16_t>);
98 static_assert(!std::is_invocable_v<L, char32_t>);
99
100 static_assert(!std::is_invocable_v<L, A>);
101 static_assert(!std::is_invocable_v<L, A*>);
102 static_assert(!std::is_invocable_v<L, E1>);
103 static_assert(!std::is_invocable_v<L, E2>);
104 }
105
106 static_assert(test<unsigned char>());
107 static_assert(test<unsigned short>());
108 static_assert(test<unsigned int>());
109 static_assert(test<unsigned long>());
110 static_assert(test<unsigned long long>());
111 #ifndef TEST_HAS_NO_INT128
112 static_assert(test<__uint128_t>());
113 #endif
114 static_assert(test<uint8_t>());
115 static_assert(test<uint16_t>());
116 static_assert(test<uint32_t>());
117 static_assert(test<uint64_t>());
118 static_assert(test<uintmax_t>());
119 static_assert(test<uintptr_t>());
120 static_assert(test<size_t>());
121
122 test<unsigned char>();
123 test<unsigned short>();
124 test<unsigned int>();
125 test<unsigned long>();
126 test<unsigned long long>();
127 #ifndef TEST_HAS_NO_INT128
128 test<__uint128_t>();
129 #endif
130 test<uint8_t>();
131 test<uint16_t>();
132 test<uint32_t>();
133 test<uint64_t>();
134 test<uintmax_t>();
135 test<uintptr_t>();
136 test<size_t>();
137
138 return 0;
139 }
140
141