feedc0de/boost_core
1
0
Fork 0
forked from boostorg/core
Code Pull Requests Activity

Use __builtin_bswap under GCC and Clang

Browse Source
This commit is contained in:
Peter Dimov
2023-05-30 19:22:00 +03:00
parent b591214103
commit f41b8f38c4
1 changed files with 16 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
include/boost/core/bit.hpp
View File

@@ -807,6 +807,20 @@ BOOST_CONSTEXPR inline boost::uint16_t byteswap_impl( boost::uint16_t x ) BOOST_
return (x << 8) | (x >> 8);
}
#if defined(__GNUC__) || defined(__clang__)
BOOST_CXX14_CONSTEXPR inline boost::uint32_t byteswap_impl( boost::uint32_t x ) BOOST_NOEXCEPT
{
return __builtin_bswap32( x );
}
BOOST_CXX14_CONSTEXPR inline boost::uint64_t byteswap_impl( boost::uint64_t x ) BOOST_NOEXCEPT
{
return __builtin_bswap64( x );
}
#else
BOOST_CXX14_CONSTEXPR inline boost::uint32_t byteswap_impl( boost::uint32_t x ) BOOST_NOEXCEPT
{
boost::uint32_t step16 = x << 16 | x >> 16;
@@ -820,6 +834,8 @@ BOOST_CXX14_CONSTEXPR inline boost::uint64_t byteswap_impl( boost::uint64_t x )
return (step16 & 0x00FF00FF00FF00FFULL) << 8 | (step16 & 0xFF00FF00FF00FF00ULL) >> 8;
}
#endif
} // namespace detail
template<class T> BOOST_CXX14_CONSTEXPR T byteswap( T x ) BOOST_NOEXCEPT