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