153 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 int popcount(T x) noexcept;13 14// Constraints: T is an unsigned integer type15// Returns: The number of bits set to one in the value of 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::popcount(T())), int);34 ASSERT_NOEXCEPT(std::popcount(T()));35 T max = std::numeric_limits<T>::max();36 37 assert(std::popcount(T(0)) == 0);38 assert(std::popcount(T(1)) == 1);39 assert(std::popcount(T(2)) == 1);40 assert(std::popcount(T(3)) == 2);41 assert(std::popcount(T(4)) == 1);42 assert(std::popcount(T(5)) == 2);43 assert(std::popcount(T(6)) == 2);44 assert(std::popcount(T(7)) == 3);45 assert(std::popcount(T(8)) == 1);46 assert(std::popcount(T(9)) == 2);47 assert(std::popcount(T(121)) == 5);48 assert(std::popcount(T(127)) == 7);49 assert(std::popcount(T(128)) == 1);50 assert(std::popcount(T(130)) == 2);51 assert(std::popcount(T(max >> 1)) == std::numeric_limits<T>::digits - 1);52 assert(std::popcount(T(max - 1)) == std::numeric_limits<T>::digits - 1);53 assert(std::popcount(max) == std::numeric_limits<T>::digits);54 55#ifndef TEST_HAS_NO_INT12856 if constexpr (std::is_same_v<T, __uint128_t>) {57 T val = 128;58 assert(std::popcount(val-1) == 7);59 assert(std::popcount(val) == 1);60 assert(std::popcount(val+1) == 2);61 val <<= 32;62 assert(std::popcount(val-1) == 39);63 assert(std::popcount(val) == 1);64 assert(std::popcount(val+1) == 2);65 val <<= 60;66 assert(std::popcount(val-1) == 99);67 assert(std::popcount(val) == 1);68 assert(std::popcount(val+1) == 2);69 70 T x = T(1) << 63;71 T y = T(1) << 64;72 assert(std::popcount(x) == 1);73 assert(std::popcount(y) == 1);74 assert(std::popcount(x+y) == 2);75 }76#endif77 78 return true;79}80 81int main(int, char**)82{83 {84 auto lambda = [](auto x) -> decltype(std::popcount(x)) {};85 using L = decltype(lambda);86 87 static_assert(!std::is_invocable_v<L, signed char>);88 static_assert(!std::is_invocable_v<L, short>);89 static_assert(!std::is_invocable_v<L, int>);90 static_assert(!std::is_invocable_v<L, long>);91 static_assert(!std::is_invocable_v<L, long long>);92#ifndef TEST_HAS_NO_INT12893 static_assert(!std::is_invocable_v<L, __int128_t>);94#endif95 96 static_assert(!std::is_invocable_v<L, std::int8_t>);97 static_assert(!std::is_invocable_v<L, std::int16_t>);98 static_assert(!std::is_invocable_v<L, std::int32_t>);99 static_assert(!std::is_invocable_v<L, std::int64_t>);100 static_assert(!std::is_invocable_v<L, std::intmax_t>);101 static_assert(!std::is_invocable_v<L, std::intptr_t>);102 static_assert(!std::is_invocable_v<L, std::ptrdiff_t>);103 104 static_assert(!std::is_invocable_v<L, bool>);105 static_assert(!std::is_invocable_v<L, char>);106 static_assert(!std::is_invocable_v<L, wchar_t>);107#ifndef TEST_HAS_NO_CHAR8_T108 static_assert(!std::is_invocable_v<L, char8_t>);109#endif110 static_assert(!std::is_invocable_v<L, char16_t>);111 static_assert(!std::is_invocable_v<L, char32_t>);112 113 static_assert(!std::is_invocable_v<L, A>);114 static_assert(!std::is_invocable_v<L, A*>);115 static_assert(!std::is_invocable_v<L, E1>);116 static_assert(!std::is_invocable_v<L, E2>);117 }118 119 static_assert(test<unsigned char>());120 static_assert(test<unsigned short>());121 static_assert(test<unsigned int>());122 static_assert(test<unsigned long>());123 static_assert(test<unsigned long long>());124#ifndef TEST_HAS_NO_INT128125 static_assert(test<__uint128_t>());126#endif127 static_assert(test<std::uint8_t>());128 static_assert(test<std::uint16_t>());129 static_assert(test<std::uint32_t>());130 static_assert(test<std::uint64_t>());131 static_assert(test<std::uintmax_t>());132 static_assert(test<std::uintptr_t>());133 static_assert(test<std::size_t>());134 135 test<unsigned char>();136 test<unsigned short>();137 test<unsigned int>();138 test<unsigned long>();139 test<unsigned long long>();140#ifndef TEST_HAS_NO_INT128141 test<__uint128_t>();142#endif143 test<std::uint8_t>();144 test<std::uint16_t>();145 test<std::uint32_t>();146 test<std::uint64_t>();147 test<std::uintmax_t>();148 test<std::uintptr_t>();149 test<std::size_t>();150 151 return 0;152}153