144 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++03, c++11, c++14, c++1710 11// template <class T>12// constexpr T bit_floor(T x) noexcept;13 14// Constraints: T is an unsigned integer type15// Returns: If x == 0, 0; otherwise the maximal value y such that bit_floor(y) is true and y <= x.16 17#include <bit>18#include <cassert>19#include <cstddef>20#include <cstdint>21#include <limits>22#include <type_traits>23 24#include "test_macros.h"25 26struct A {};27enum E1 : unsigned char { rEd };28enum class E2 : unsigned char { red };29 30template <class T>31constexpr bool test()32{33 ASSERT_SAME_TYPE(decltype(std::bit_floor(T())), T);34 LIBCPP_ASSERT_NOEXCEPT(std::bit_floor(T()));35 T max = std::numeric_limits<T>::max();36 37 assert(std::bit_floor(T(0)) == T(0));38 assert(std::bit_floor(T(1)) == T(1));39 assert(std::bit_floor(T(2)) == T(2));40 assert(std::bit_floor(T(3)) == T(2));41 assert(std::bit_floor(T(4)) == T(4));42 assert(std::bit_floor(T(5)) == T(4));43 assert(std::bit_floor(T(6)) == T(4));44 assert(std::bit_floor(T(7)) == T(4));45 assert(std::bit_floor(T(8)) == T(8));46 assert(std::bit_floor(T(9)) == T(8));47 assert(std::bit_floor(T(125)) == T(64));48 assert(std::bit_floor(T(126)) == T(64));49 assert(std::bit_floor(T(127)) == T(64));50 assert(std::bit_floor(T(128)) == T(128));51 assert(std::bit_floor(T(129)) == T(128));52 assert(std::bit_floor(max) == T(max - (max >> 1)));53 54#ifndef TEST_HAS_NO_INT12855 if constexpr (std::is_same_v<T, __uint128_t>) {56 T val = T(128) << 32;57 assert(std::bit_floor(val-1) == val/2);58 assert(std::bit_floor(val) == val);59 assert(std::bit_floor(val+1) == val);60 val <<= 60;61 assert(std::bit_floor(val-1) == val/2);62 assert(std::bit_floor(val) == val);63 assert(std::bit_floor(val+1) == val);64 }65#endif66 67 return true;68}69 70int main(int, char**)71{72 {73 auto lambda = [](auto x) -> decltype(std::bit_floor(x)) {};74 using L = decltype(lambda);75 76 static_assert(!std::is_invocable_v<L, signed char>);77 static_assert(!std::is_invocable_v<L, short>);78 static_assert(!std::is_invocable_v<L, int>);79 static_assert(!std::is_invocable_v<L, long>);80 static_assert(!std::is_invocable_v<L, long long>);81#ifndef TEST_HAS_NO_INT12882 static_assert(!std::is_invocable_v<L, __int128_t>);83#endif84 85 static_assert(!std::is_invocable_v<L, std::int8_t>);86 static_assert(!std::is_invocable_v<L, std::int16_t>);87 static_assert(!std::is_invocable_v<L, std::int32_t>);88 static_assert(!std::is_invocable_v<L, std::int64_t>);89 static_assert(!std::is_invocable_v<L, std::intmax_t>);90 static_assert(!std::is_invocable_v<L, std::intptr_t>);91 static_assert(!std::is_invocable_v<L, std::ptrdiff_t>);92 93 static_assert(!std::is_invocable_v<L, bool>);94 static_assert(!std::is_invocable_v<L, char>);95 static_assert(!std::is_invocable_v<L, wchar_t>);96#ifndef TEST_HAS_NO_CHAR8_T97 static_assert(!std::is_invocable_v<L, char8_t>);98#endif99 static_assert(!std::is_invocable_v<L, char16_t>);100 static_assert(!std::is_invocable_v<L, char32_t>);101 102 static_assert(!std::is_invocable_v<L, A>);103 static_assert(!std::is_invocable_v<L, A*>);104 static_assert(!std::is_invocable_v<L, E1>);105 static_assert(!std::is_invocable_v<L, E2>);106 }107 108 static_assert(test<unsigned char>());109 static_assert(test<unsigned short>());110 static_assert(test<unsigned int>());111 static_assert(test<unsigned long>());112 static_assert(test<unsigned long long>());113#ifndef TEST_HAS_NO_INT128114 static_assert(test<__uint128_t>());115#endif116 117 static_assert(test<std::uint8_t>());118 static_assert(test<std::uint16_t>());119 static_assert(test<std::uint32_t>());120 static_assert(test<std::uint64_t>());121 static_assert(test<std::uintmax_t>());122 static_assert(test<std::uintptr_t>());123 static_assert(test<std::size_t>());124 125 test<unsigned char>();126 test<unsigned short>();127 test<unsigned int>();128 test<unsigned long>();129 test<unsigned long long>();130#ifndef TEST_HAS_NO_INT128131 test<__uint128_t>();132#endif133 134 test<std::uint8_t>();135 test<std::uint16_t>();136 test<std::uint32_t>();137 test<std::uint64_t>();138 test<std::uintmax_t>();139 test<std::uintptr_t>();140 test<std::size_t>();141 142 return 0;143}144