diff options
Diffstat (limited to 'libcxx/test/std/numerics/bit/bitops.count/countr_zero.pass.cpp')
| -rw-r--r-- | libcxx/test/std/numerics/bit/bitops.count/countr_zero.pass.cpp | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/libcxx/test/std/numerics/bit/bitops.count/countr_zero.pass.cpp b/libcxx/test/std/numerics/bit/bitops.count/countr_zero.pass.cpp new file mode 100644 index 00000000000..8d355bfb51b --- /dev/null +++ b/libcxx/test/std/numerics/bit/bitops.count/countr_zero.pass.cpp @@ -0,0 +1,169 @@ +//===----------------------------------------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is dual licensed under the MIT and the University of Illinois Open +// Source Licenses. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17 + +// template <class T> +// constexpr int countr_zero(T x) noexcept; + +// Returns: The number of consecutive 0 bits, starting from the most significant bit. +// [ Note: Returns N if x == 0. ] +// +// Remarks: This function shall not participate in overload resolution unless +// T is an unsigned integer type + +#include <bit> +#include <cstdint> +#include <type_traits> +#include <cassert> + +#include "test_macros.h" + +class A{}; +enum E1 : unsigned char { rEd }; +enum class E2 : unsigned char { red }; + +template <typename T> +constexpr bool constexpr_test() +{ + const int dig = std::numeric_limits<T>::digits; + return std::countr_zero(T(0)) == dig + && std::countr_zero(T(1)) == 0 + && std::countr_zero(T(2)) == 1 + && std::countr_zero(T(3)) == 0 + && std::countr_zero(T(4)) == 2 + && std::countr_zero(T(5)) == 0 + && std::countr_zero(T(6)) == 1 + && std::countr_zero(T(7)) == 0 + && std::countr_zero(T(8)) == 3 + && std::countr_zero(T(9)) == 0 + && std::countr_zero(std::numeric_limits<T>::max()) == 0 + ; +} + + +template <typename T> +void runtime_test() +{ + ASSERT_SAME_TYPE(int, decltype(std::countr_zero(T(0)))); + ASSERT_NOEXCEPT( std::countr_zero(T(0))); + + assert( std::countr_zero(T(121)) == 0); + assert( std::countr_zero(T(122)) == 1); + assert( std::countr_zero(T(123)) == 0); + assert( std::countr_zero(T(124)) == 2); + assert( std::countr_zero(T(125)) == 0); + assert( std::countr_zero(T(126)) == 1); + assert( std::countr_zero(T(127)) == 0); + assert( std::countr_zero(T(128)) == 7); + assert( std::countr_zero(T(129)) == 0); + assert( std::countr_zero(T(130)) == 1); +} + +int main() +{ + + { + auto lambda = [](auto x) -> decltype(std::countr_zero(x)) {}; + using L = decltype(lambda); + + static_assert( std::is_invocable_v<L, unsigned char>, ""); + static_assert( std::is_invocable_v<L, unsigned int>, ""); + static_assert( std::is_invocable_v<L, unsigned long>, ""); + static_assert( std::is_invocable_v<L, unsigned long long>, ""); + + static_assert( std::is_invocable_v<L, uint8_t>, ""); + static_assert( std::is_invocable_v<L, uint16_t>, ""); + static_assert( std::is_invocable_v<L, uint32_t>, ""); + static_assert( std::is_invocable_v<L, uint64_t>, ""); + static_assert( std::is_invocable_v<L, size_t>, ""); + + static_assert( std::is_invocable_v<L, uintmax_t>, ""); + static_assert( std::is_invocable_v<L, uintptr_t>, ""); + + + static_assert(!std::is_invocable_v<L, int>, ""); + static_assert(!std::is_invocable_v<L, signed int>, ""); + static_assert(!std::is_invocable_v<L, long>, ""); + static_assert(!std::is_invocable_v<L, long long>, ""); + + static_assert(!std::is_invocable_v<L, int8_t>, ""); + static_assert(!std::is_invocable_v<L, int16_t>, ""); + static_assert(!std::is_invocable_v<L, int32_t>, ""); + static_assert(!std::is_invocable_v<L, int64_t>, ""); + static_assert(!std::is_invocable_v<L, ptrdiff_t>, ""); + + static_assert(!std::is_invocable_v<L, bool>, ""); + static_assert(!std::is_invocable_v<L, signed char>, ""); + static_assert(!std::is_invocable_v<L, char16_t>, ""); + static_assert(!std::is_invocable_v<L, char32_t>, ""); + +#ifndef _LIBCPP_HAS_NO_INT128 + static_assert( std::is_invocable_v<L, __uint128_t>, ""); + static_assert(!std::is_invocable_v<L, __int128_t>, ""); +#endif + + static_assert(!std::is_invocable_v<L, A>, ""); + static_assert(!std::is_invocable_v<L, E1>, ""); + static_assert(!std::is_invocable_v<L, E2>, ""); + } + + static_assert(constexpr_test<unsigned char>(), ""); + static_assert(constexpr_test<unsigned short>(), ""); + static_assert(constexpr_test<unsigned>(), ""); + static_assert(constexpr_test<unsigned long>(), ""); + static_assert(constexpr_test<unsigned long long>(), ""); + + static_assert(constexpr_test<uint8_t>(), ""); + static_assert(constexpr_test<uint16_t>(), ""); + static_assert(constexpr_test<uint32_t>(), ""); + static_assert(constexpr_test<uint64_t>(), ""); + static_assert(constexpr_test<size_t>(), ""); + static_assert(constexpr_test<uintmax_t>(), ""); + static_assert(constexpr_test<uintptr_t>(), ""); + +#ifndef _LIBCPP_HAS_NO_INT128 + static_assert(constexpr_test<__uint128_t>(), ""); +#endif + + runtime_test<unsigned char>(); + runtime_test<unsigned>(); + runtime_test<unsigned short>(); + runtime_test<unsigned long>(); + runtime_test<unsigned long long>(); + + runtime_test<uint8_t>(); + runtime_test<uint16_t>(); + runtime_test<uint32_t>(); + runtime_test<uint64_t>(); + runtime_test<size_t>(); + runtime_test<uintmax_t>(); + runtime_test<uintptr_t>(); + +#ifndef _LIBCPP_HAS_NO_INT128 + runtime_test<__uint128_t>(); + + { + __uint128_t val = 128; + + val <<= 32; + assert( std::countr_zero(val-1) == 0); + assert( std::countr_zero(val) == 39); + assert( std::countr_zero(val+1) == 0); + val <<= 2; + assert( std::countr_zero(val-1) == 0); + assert( std::countr_zero(val) == 41); + assert( std::countr_zero(val+1) == 0); + val <<= 3; + assert( std::countr_zero(val-1) == 0); + assert( std::countr_zero(val) == 44); + assert( std::countr_zero(val+1) == 0); + } +#endif + +} |
