diff options
Diffstat (limited to 'libstdc++-v3/testsuite/26_numerics/bit/bit.pow.two/log2p1.cc')
-rw-r--r-- | libstdc++-v3/testsuite/26_numerics/bit/bit.pow.two/log2p1.cc | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/libstdc++-v3/testsuite/26_numerics/bit/bit.pow.two/log2p1.cc b/libstdc++-v3/testsuite/26_numerics/bit/bit.pow.two/log2p1.cc new file mode 100644 index 00000000000..142f6ee857d --- /dev/null +++ b/libstdc++-v3/testsuite/26_numerics/bit/bit.pow.two/log2p1.cc @@ -0,0 +1,109 @@ +// Copyright (C) 2018 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// <http://www.gnu.org/licenses/>. + +// { dg-options "-std=gnu++2a" } +// { dg-do compile { target c++2a } } + +#include <bit> + +template<typename UInt> +constexpr auto +test(UInt x) +-> decltype(std::log2p1(x)) +{ + static_assert( noexcept(std::log2p1(x)) ); + + static_assert( std::log2p1(UInt(0)) == 0 ); + static_assert( std::log2p1(UInt(1)) == 1 ); + static_assert( std::log2p1(UInt(2)) == 2 ); + static_assert( std::log2p1(UInt(3)) == 2 ); + static_assert( std::log2p1(UInt(4)) == 3 ); + static_assert( std::log2p1(UInt(0x11)) == 5 ); + static_assert( std::log2p1(UInt(0x20)) == 6 ); + + if constexpr (std::numeric_limits<UInt>::digits > 8) + { + static_assert( std::log2p1(UInt(0x201)) == 10 ); + static_assert( std::log2p1(UInt(0x8ff)) == 12 ); + static_assert( std::log2p1(UInt(0x1000)) == 13 ); + } + + if constexpr (std::numeric_limits<UInt>::digits > 32) + { + static_assert( std::log2p1(UInt(0xabcdef)) == 24 ); + static_assert( std::log2p1(UInt(0x1000000)) == 25 ); + static_assert( std::log2p1(UInt(0x1000001)) == 25 ); + } + + if constexpr (std::numeric_limits<UInt>::digits > 64) + { + static_assert( std::log2p1(UInt(1) << 64) == 65 ); + static_assert( std::log2p1(UInt(3) << 64) == 66 ); + } + + return true; +} + +static_assert( test( (unsigned char)0 ) ); +static_assert( test( (unsigned short)0 ) ); +static_assert( test( (unsigned int)0 ) ); +static_assert( test( (unsigned long)0 ) ); +static_assert( test( (unsigned long long)0 ) ); + +// std::log2p1(T) shall not participate in overload resolution +// unless T is an unsigned integer type. +struct X { constexpr bool did_not_match() { return true; } }; +constexpr X test(...) { return X{}; } +static_assert( test( (bool)0 ).did_not_match() ); +static_assert( test( (char)0 ).did_not_match() ); +static_assert( test( (int)0 ).did_not_match() ); +static_assert( test( (char16_t)0 ).did_not_match() ); +static_assert( test( (float)0 ).did_not_match() ); +static_assert( test( (void*)0 ).did_not_match() ); +static_assert( test( X{} ).did_not_match() ); +enum E : unsigned { e }; +static_assert( test( e ).did_not_match() ); + +#ifndef __STRICT_ANSI__ +#include <cstddef> +static_assert( std::log2p1(std::byte{0}) == std::byte{0} ); +static_assert( std::log2p1(std::byte{1}) == std::byte{1} ); +static_assert( std::log2p1(std::byte{2}) == std::byte{2} ); +static_assert( std::log2p1(std::byte{3}) == std::byte{2} ); +static_assert( std::log2p1(std::byte{100}) == std::byte{7} ); +static_assert( std::log2p1(std::byte{128}) == std::byte{8} ); +static_assert( std::log2p1(std::byte{255}) == std::byte{8} ); +#else +static_assert( test( (std::byte)0 ).did_not_match() ); +#endif + +#if !defined(__STRICT_ANSI__) && defined _GLIBCXX_USE_INT128 +static_assert( test( (unsigned __int128)0 ) ); +static_assert( test( (__int128)0 ).did_not_match() ); +#endif +#if defined(__GLIBCXX_TYPE_INT_N_0) +static_assert( test( (unsigned __GLIBCXX_TYPE_INT_N_0)0 ) ); +static_assert( test( (__GLIBCXX_TYPE_INT_N_0)0 ).did_not_match() ); +#endif +#if defined(__GLIBCXX_TYPE_INT_N_1) +static_assert( test( (unsigned __GLIBCXX_TYPE_INT_N_1)0 ) ); +static_assert( test( (__GLIBCXX_TYPE_INT_N_1)0 ).did_not_match() ); +#endif +#if defined(__GLIBCXX_TYPE_INT_N_2) +static_assert( test( (unsigned __GLIBCXX_TYPE_INT_N_2)0 ) ); +static_assert( test( (__GLIBCXX_TYPE_INT_N_2)0 ).did_not_match() ); +#endif |