| /* ffs -- find first set bit in a word, counted from least significant end. |
| For Intel 80x86, x>=3. |
| 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 |
| |
| #ifdef __GNUC__ |
| |
| int |
| __ffs (int x) |
| { |
| int cnt; |
| int tmp; |
| |
| asm ("xorl %0,%0\n" /* Set CNT to zero. */ |
| "bsfl %2,%1\n" /* Count low bits in X and store in %1. */ |
| "jz 1f\n" /* Jump if OK, i.e. X was non-zero. */ |
| "leal 1(%1),%0\n" /* Return bsfl-result plus one on %0. */ |
| "1:" : "=&a" (cnt), "=r" (tmp) : "rm" (x)); |
| |
| return 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 |