sysdeps/powerpc/ffs.c

   1 /* Find first set bit in a word, counted from least significant end.
   2    For PowerPC.
   3    Copyright (C) 1991, 1992, 1997, 1998 Free Software Foundation, Inc.
   4    Contributed by Torbjorn Granlund (tege@sics.se).
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include <string.h>
  22
  23 int
  24 __ffs (int x)
  25 {
  26   int cnt;
  27
  28   asm ("cntlzw %0,%1" : "=r" (cnt) : "r" (x & -x));
  29   return 32 - cnt;
  30 }
  31 weak_alias (__ffs, ffs)
  32 weak_alais (__ffs, ffsl)