glibc/sysdeps/m68k/ffs.c

48 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) 1991-2016 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 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, see
<http://www.gnu.org/licenses/>. */
#define ffsl __something_else
#include <string.h>
#undef ffs
#if defined (__GNUC__) && defined (__mc68020__)
int
__ffs (int x)
{
int cnt;
asm ("bfffo %1{#0:#0},%0" : "=d" (cnt) : "dm" (x & -x));
return 32 - cnt;
}
weak_alias (__ffs, ffs)
libc_hidden_def (__ffs)
libc_hidden_builtin_def (ffs)
#undef ffsl
weak_alias (__ffs, ffsl)
#else
#include <string/ffs.c>
#endif