diff options
Diffstat (limited to 'REORG.TODO/sysdeps/i386/ffs.c')
| -rw-r--r-- | REORG.TODO/sysdeps/i386/ffs.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/i386/ffs.c b/REORG.TODO/sysdeps/i386/ffs.c new file mode 100644 index 0000000000..c229c8166e --- /dev/null +++ b/REORG.TODO/sysdeps/i386/ffs.c @@ -0,0 +1,50 @@ +/* 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) 1991-2017 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 |