glibc/sysdeps/m68k/ffs.c

45 lines
1.3 KiB
C

/* ffs -- find first set bit in a word, counted from least significant end.
For mc68020, mc68030, mc68040.
This file is part of the GNU C Library.
Copyright (C) 1991, 1992, 1997 Free Software Foundation, Inc.
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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <string.h>
#undef ffs
#if defined (__GNUC__) && defined (__mc68020__)
int
__ffs (x)
int x;
{
int cnt;
asm ("bfffo %1{#0:#0},%0" : "=d" (cnt) : "dm" (x & -x));
return 32 - cnt;
}
weak_alias (__ffs, ffs)
#else
#include <sysdeps/generic/ffs.c>
#endif