1/* ffs -- find first set bit in a word, counted from least significant end.
2 For mc68020, mc68030, mc68040.
3 This file is part of the GNU C Library.
4 Copyright (C) 1991-2022 Free Software Foundation, Inc.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the 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 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library. If not, see
18 <https://www.gnu.org/licenses/>. */
19
20#define ffsl __something_else
21#include <string.h>
22
23#undef ffs
24
25#if defined (__GNUC__) && defined (__mc68020__)
26
27int
28__ffs (int x)
29{
30 int cnt;
31
32 asm ("bfffo %1{#0:#0},%0" : "=d" (cnt) : "dm" (x & -x));
33
34 return 32 - cnt;
35}
36weak_alias (__ffs, ffs)
37libc_hidden_def (__ffs)
38libc_hidden_builtin_def (ffs)
39#undef ffsl
40weak_alias (__ffs, ffsl)
41
42#else
43
44#include <string/ffs.c>
45
46#endif
47

source code of glibc/sysdeps/m68k/ffs.c