139 lines
4.4 KiB
C++
139 lines
4.4 KiB
C++
//===----------------------------------------------------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is dual licensed under the MIT and the University of Illinois Open
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// Source Licenses. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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// UNSUPPORTED: c++03, c++11, c++14, c++17
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// template <class T>
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// constexpr int countl_zero(T x) noexcept;
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// Constraints: T is an unsigned integer type
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// Returns: The number of consecutive 0 bits, starting from the most significant bit.
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// [ Note: Returns N if x == 0. ]
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#include <bit>
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#include <cassert>
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#include <cstdint>
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#include <type_traits>
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#include "test_macros.h"
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struct A {};
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enum E1 : unsigned char { rEd };
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enum class E2 : unsigned char { red };
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template <class T>
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constexpr bool test()
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{
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ASSERT_SAME_TYPE(decltype(std::countl_zero(T())), int);
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ASSERT_NOEXCEPT(std::countl_zero(T()));
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T max = std::numeric_limits<T>::max();
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int dig = std::numeric_limits<T>::digits;
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assert(std::countl_zero(T(0)) == dig);
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assert(std::countl_zero(T(1)) == dig - 1);
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assert(std::countl_zero(T(2)) == dig - 2);
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assert(std::countl_zero(T(3)) == dig - 2);
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assert(std::countl_zero(T(4)) == dig - 3);
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assert(std::countl_zero(T(5)) == dig - 3);
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assert(std::countl_zero(T(6)) == dig - 3);
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assert(std::countl_zero(T(7)) == dig - 3);
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assert(std::countl_zero(T(8)) == dig - 4);
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assert(std::countl_zero(T(9)) == dig - 4);
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assert(std::countl_zero(T(127)) == dig - 7);
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assert(std::countl_zero(T(128)) == dig - 8);
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assert(std::countl_zero(max) == 0);
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#ifndef _LIBCPP_HAS_NO_INT128
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if constexpr (std::is_same_v<T, __uint128_t>) {
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T val = T(128) << 32;
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assert(std::countl_zero(val-1) == 89);
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assert(std::countl_zero(val) == 88);
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assert(std::countl_zero(val+1) == 88);
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val <<= 60;
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assert(std::countl_zero(val-1) == 29);
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assert(std::countl_zero(val) == 28);
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assert(std::countl_zero(val+1) == 28);
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}
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#endif
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return true;
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}
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int main(int, char**)
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{
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{
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auto lambda = [](auto x) -> decltype(std::countl_zero(x)) {};
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using L = decltype(lambda);
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static_assert(!std::is_invocable_v<L, signed char>);
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static_assert(!std::is_invocable_v<L, short>);
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static_assert(!std::is_invocable_v<L, int>);
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static_assert(!std::is_invocable_v<L, long>);
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static_assert(!std::is_invocable_v<L, long long>);
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#ifndef _LIBCPP_HAS_NO_INT128
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static_assert(!std::is_invocable_v<L, __int128_t>);
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#endif
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static_assert(!std::is_invocable_v<L, int8_t>);
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static_assert(!std::is_invocable_v<L, int16_t>);
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static_assert(!std::is_invocable_v<L, int32_t>);
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static_assert(!std::is_invocable_v<L, int64_t>);
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static_assert(!std::is_invocable_v<L, intmax_t>);
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static_assert(!std::is_invocable_v<L, intptr_t>);
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static_assert(!std::is_invocable_v<L, ptrdiff_t>);
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static_assert(!std::is_invocable_v<L, bool>);
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static_assert(!std::is_invocable_v<L, char>);
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static_assert(!std::is_invocable_v<L, wchar_t>);
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#ifndef _LIBCPP_HAS_NO_CHAR8_T
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static_assert(!std::is_invocable_v<L, char8_t>);
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#endif
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static_assert(!std::is_invocable_v<L, char16_t>);
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static_assert(!std::is_invocable_v<L, char32_t>);
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static_assert(!std::is_invocable_v<L, A>);
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static_assert(!std::is_invocable_v<L, A*>);
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static_assert(!std::is_invocable_v<L, E1>);
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static_assert(!std::is_invocable_v<L, E2>);
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}
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static_assert(test<unsigned char>());
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static_assert(test<unsigned short>());
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static_assert(test<unsigned int>());
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static_assert(test<unsigned long>());
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static_assert(test<unsigned long long>());
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#ifndef _LIBCPP_HAS_NO_INT128
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static_assert(test<__uint128_t>());
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#endif
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static_assert(test<uint8_t>());
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static_assert(test<uint16_t>());
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static_assert(test<uint32_t>());
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static_assert(test<uint64_t>());
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static_assert(test<uintmax_t>());
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static_assert(test<uintptr_t>());
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static_assert(test<size_t>());
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test<unsigned char>();
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test<unsigned short>();
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test<unsigned int>();
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test<unsigned long>();
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test<unsigned long long>();
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#ifndef _LIBCPP_HAS_NO_INT128
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test<__uint128_t>();
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#endif
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test<uint8_t>();
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test<uint16_t>();
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test<uint32_t>();
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test<uint64_t>();
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test<uintmax_t>();
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test<uintptr_t>();
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test<size_t>();
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return 0;
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}
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