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1.1 root 1: /*
2: * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3: *
4: * @APPLE_LICENSE_HEADER_START@
5: *
6: * The contents of this file constitute Original Code as defined in and
7: * are subject to the Apple Public Source License Version 1.1 (the
8: * "License"). You may not use this file except in compliance with the
9: * License. Please obtain a copy of the License at
10: * http://www.apple.com/publicsource and read it before using this file.
11: *
12: * This Original Code and all software distributed under the License are
13: * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
14: * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15: * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
16: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
17: * License for the specific language governing rights and limitations
18: * under the License.
19: *
20: * @APPLE_LICENSE_HEADER_END@
21: */
22: /*
23: * @OSF_COPYRIGHT@
24: */
25: /*
26: * HISTORY
27: *
28: * Revision 1.1.1.1 1998/09/22 21:05:35 wsanchez
29: * Import of Mac OS X kernel (~semeria)
30: *
31: * Revision 1.2 1998/04/29 17:35:55 mburg
32: * MK7.3 merger
33: *
34: * Revision 1.1.24.1 1998/02/03 09:27:19 gdt
35: * Merge up to MK7.3
36: * [1998/02/03 09:12:57 gdt]
37: *
38: * Revision 1.1.21.1 1996/11/29 16:57:21 stephen
39: * nmklinux_1.0b3_shared into pmk1.1
40: * Added explanatory note.
41: * [1996/04/10 16:54:46 emcmanus]
42: *
43: * Revision 1.1.22.1 1997/06/17 02:57:05 devrcs
44: * Added `testbit()' routine.
45: * [1996/03/18 15:21:50 rkc]
46: *
47: * Revision 1.1.7.3 1995/01/10 05:10:36 devrcs
48: * mk6 CR801 - copyright marker not FREE_
49: * [1994/12/01 19:24:54 dwm]
50: *
51: * Revision 1.1.7.1 1994/06/14 16:59:49 bolinger
52: * Merge up to NMK17.2.
53: * [1994/06/14 16:53:29 bolinger]
54: *
55: * Revision 1.1.5.1 1994/04/11 09:36:31 bernadat
56: * Checked in NMK16_2 revision
57: * [94/03/15 bernadat]
58: *
59: * Revision 1.1.3.1 1993/12/23 08:53:13 bernadat
60: * Checked in bolinger_860ci revision.
61: * [93/11/29 bernadat]
62: *
63: * Revision 1.1.1.2 1993/09/12 15:44:20 bolinger
64: * Initial checkin of 860 modifications; MD files from NMK14.8.
65: *
66: * $EndLog$
67: */
68: /*
69: * C version of bit manipulation routines now required by kernel.
70: * Should be replaced with assembler versions in any real port.
71: *
72: * Note that these routines use little-endian numbering for bits (i.e.,
73: * the bit number corresponds to the associated power-of-2).
74: */
75: #include <mach/machine/vm_param.h> /* for BYTE_SIZE */
76:
77: #define INT_SIZE (BYTE_SIZE * sizeof (int))
78:
79: /*
80: * Set indicated bit in bit string.
81: */
82: void
83: setbit(int bitno, int *s)
84: {
85: for ( ; INT_SIZE <= bitno; bitno -= INT_SIZE, ++s)
86: ;
87: *s |= 1 << bitno;
88: }
89:
90: /*
91: * Clear indicated bit in bit string.
92: */
93: void
94: clrbit(int bitno, int *s)
95: {
96: for ( ; INT_SIZE <= bitno; bitno -= INT_SIZE, ++s)
97: ;
98: *s &= ~(1 << bitno);
99: }
100:
101: /*
102: * Find first bit set in bit string.
103: */
104: int
105: ffsbit(int *s)
106: {
107: int offset, mask;
108:
109: for (offset = 0; !*s; offset += INT_SIZE, ++s)
110: ;
111: for (mask = 1; mask; mask <<= 1, ++offset)
112: if (mask & *s)
113: return (offset);
114: /*
115: * Shouldn't get here
116: */
117: return (0);
118: }
119:
120: /*
121: * Test if indicated bit is set in bit string.
122: */
123: int
124: testbit(int bitno, int *s)
125: {
126: for ( ; INT_SIZE <= bitno; bitno -= INT_SIZE, ++s)
127: ;
128: return(*s & (1 << bitno));
129: }
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