1/*
2 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/* Copyright (c) 1992, 1997-1998 Apple Computer, Inc.  All rights reserved.
29 *
30 *      File:  machdep/ppc/libc/ffs.s
31 *
32 *	int ffs(int value)
33 *
34 *	DESCRIPTION
35 *		The ffs() function finds the first bit set in value and returns the
36 *		index of that bit.  Bits are numbered starting from 1, starting at
37 *		the right-most bit. A return value of 0 means that the argument was
38 *
39 * HISTORY
40 *	14-Aug-1998	Umesh Vaishampayan	(umeshv@apple.com)
41 *		Optimized!
42 *
43 *  10-Mar-1998 Matt Watson (mwatson@apple.com)
44 *      Correctified
45 *
46 *  19-Jan-1998 Matt Watson (mwatson@apple.com)
47 *      Simplified
48 *
49 *  24-Jan-1997 Umesh Vaishampayan (umeshv@NeXT.com)
50 *      Ported to PPC.
51 */
52
53.text
54.align 4
55.globl _ffs
56_ffs:					/* Cycles */
57	neg		r0,r3		/* 0 */
58	and		r3,r0,r3	/* 1 */
59	li		r4, 32		/* 1 */
60	cntlzw	r3,r3		/* 2 */
61	subf	r3,r3,r4	/* 3 */
62	blr
63
64	.globl	_abs
65_abs:
66	srawi r0,r3,31
67	xor r3,r0,r3
68	subf r3,r0,r3
69	blr
70
71