boostorg/unordered
1
0
Fork 1
mirror of https://github.com/boostorg/unordered.git synced 2025-09-25 07:10:57 +02:00
Code Issues Packages Projects Releases Wiki Activity

microoptimized unchecked_countr_zero for GCC/Clang

Browse Source
This commit is contained in:
joaquintides
2025-08-26 17:08:01 +02:00
committed by GitHub
parent 6fd63ab727
commit cc9a787f14
1 changed files with 2 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
include/boost/unordered/detail/foa/core.hpp
View File

@@ -923,6 +923,8 @@ inline unsigned int unchecked_countr_zero(int x)
unsigned long r; unsigned long r;
_BitScanForward(&r,(unsigned long)x); _BitScanForward(&r,(unsigned long)x);
return (unsigned int)r; return (unsigned int)r;
#elif defined(BOOST_GCC)||defined(BOOST_CLANG)
return (unsigned int)__builtin_ctz((unsigned int)x);
#else #else
BOOST_UNORDERED_ASSUME(x!=0); BOOST_UNORDERED_ASSUME(x!=0);
return (unsigned int)boost::core::countr_zero((unsigned int)x); return (unsigned int)boost::core::countr_zero((unsigned int)x);