boostorg/unordered
1
0
Fork 1
mirror of https://github.com/boostorg/unordered.git synced 2025-07-31 03:47:16 +02:00
Code Issues Packages Projects Releases Wiki Activity

Update mulx multipliers

Browse Source
This commit is contained in:
Peter Dimov
2023-01-27 08:00:40 +02:00
parent e56aac2e98
commit 9bc471310e
1 changed files with 4 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
include/boost/unordered/detail/mulx.hpp
View File

@ -94,15 +94,17 @@ inline boost::uint32_t mulx32( boost::uint32_t x, boost::uint32_t y )
#endif #endif
#endif #endif
// multipliers from https://arxiv.org/abs/2001.05304
inline std::size_t mulx( std::size_t x ) noexcept inline std::size_t mulx( std::size_t x ) noexcept
{ {
#if defined(BOOST_UNORDERED_64B_ARCHITECTURE) #if defined(BOOST_UNORDERED_64B_ARCHITECTURE)
return (std::size_t)mulx64( (boost::uint64_t)x, 0x9E3779B97F4A7C15ull ); return (std::size_t)mulx64( (boost::uint64_t)x, 0xDEFBA91144F2B375ull );
#else /* 32 bits assumed */ #else /* 32 bits assumed */
return mulx32( x, 0x9E3779B9u ); return mulx32( x, 0xE817FB2Du );
#endif #endif
} }