glibc/ports/sysdeps/arm/armv6t2/ffs.S

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2013-02-13 20:06:42 +00:00
/* ffs -- find first set bit in an int, from least significant end.
Copyright (C) 2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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/>. */
#include <sysdep.h>
.syntax unified
.text
ENTRY (__ffs)
cmp r0, #0
rbit r0, r0
itt ne
clzne r0, r0
addne r0, r0, #1
bx lr
END (__ffs)
weak_alias (__ffs, ffs)
weak_alias (__ffs, ffsl)
libc_hidden_builtin_def (ffs)