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/*
29 * @OSF_COPYRIGHT@
30 */
31/*
32 * HISTORY
33 *
34 * Revision 1.1.1.1  1998/09/22 21:05:35  wsanchez
35 * Import of Mac OS X kernel (~semeria)
36 *
37 * Revision 1.2  1998/04/29 17:35:55  mburg
38 * MK7.3 merger
39 *
40 * Revision 1.1.24.1  1998/02/03  09:27:19  gdt
41 * 	Merge up to MK7.3
42 * 	[1998/02/03  09:12:57  gdt]
43 *
44 * Revision 1.1.21.1  1996/11/29  16:57:21  stephen
45 * 	nmklinux_1.0b3_shared into pmk1.1
46 * 	Added explanatory note.
47 * 	[1996/04/10  16:54:46  emcmanus]
48 *
49 * Revision 1.1.22.1  1997/06/17  02:57:05  devrcs
50 * 	Added `testbit()' routine.
51 * 	[1996/03/18  15:21:50  rkc]
52 *
53 * Revision 1.1.7.3  1995/01/10  05:10:36  devrcs
54 * 	mk6 CR801 - copyright marker not FREE_
55 * 	[1994/12/01  19:24:54  dwm]
56 *
57 * Revision 1.1.7.1  1994/06/14  16:59:49  bolinger
58 * 	Merge up to NMK17.2.
59 * 	[1994/06/14  16:53:29  bolinger]
60 *
61 * Revision 1.1.5.1  1994/04/11  09:36:31  bernadat
62 * 	Checked in NMK16_2 revision
63 * 	[94/03/15            bernadat]
64 *
65 * Revision 1.1.3.1  1993/12/23  08:53:13  bernadat
66 * 	Checked in bolinger_860ci revision.
67 * 	[93/11/29            bernadat]
68 *
69 * Revision 1.1.1.2  1993/09/12  15:44:20  bolinger
70 * 	Initial checkin of 860 modifications; MD files from NMK14.8.
71 *
72 * $EndLog$
73 */
74/*
75 * C version of bit manipulation routines now required by kernel.
76 * Should be replaced with assembler versions in any real port.
77 *
78 * Note that these routines use little-endian numbering for bits (i.e.,
79 * the bit number corresponds to the associated power-of-2).
80 */
81#include <mach/machine/vm_param.h>	/* for BYTE_SIZE */
82
83#define INT_SIZE	(BYTE_SIZE * sizeof (int))
84
85/*
86 * Set indicated bit in bit string.
87 */
88void
89setbit(int bitno, int *s)
90{
91	for ( ; INT_SIZE <= bitno; bitno -= INT_SIZE, ++s)
92		;
93	*s |= 1 << bitno;
94}
95
96/*
97 * Clear indicated bit in bit string.
98 */
99void
100clrbit(int bitno, int *s)
101{
102	for ( ; INT_SIZE <= bitno; bitno -= INT_SIZE, ++s)
103		;
104	*s &= ~(1 << bitno);
105}
106
107/*
108 * Find first bit set in bit string.
109 */
110int
111ffsbit(int *s)
112{
113	int offset, mask;
114
115	for (offset = 0; !*s; offset += INT_SIZE, ++s)
116		;
117	for (mask = 1; mask; mask <<= 1, ++offset)
118		if (mask & *s)
119			return (offset);
120	/*
121	 * Shouldn't get here
122	 */
123	return (0);
124}
125
126/*
127 * Test if indicated bit is set in bit string.
128 */
129int
130testbit(int bitno, int *s)
131{
132	for ( ; INT_SIZE <= bitno; bitno -= INT_SIZE, ++s)
133		;
134	return(*s & (1 << bitno));
135}
136