glibc/sysdeps/rs6000/ffs.c

42 lines
1.2 KiB
C

/* ffs -- find first set bit in a word, counted from least significant end.
For IBM rs6000.
Copyright (C) 1991, 1992, 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Torbjorn Granlund (tege@sics.se).
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <string.h>
#undef ffs
#ifdef __GNUC__
int
__ffs (x)
int x;
{
int cnt;
asm ("cntlz %0,%1" : "=r" (cnt) : "r" (x & -x));
return 32 - cnt;
}
weak_alias (__ffs, ffs)
#else
#include <sysdeps/generic/ffs.c>
#endif