1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
|
/* $NetBSD: bitstring.h,v 1.4 1994/10/26 00:55:45 cgd Exp $ */
/*
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Paul Vixie.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* @(#)bitstring.h 5.2 (Berkeley) 4/4/90
*/
#ifndef _BITSTRING_H_
#define _BITSTRING_H_
/* modified for SV/AT and bitstring bugfix by M.R.Murphy, 11oct91
* bitstr_size changed gratuitously, but shorter
* bit_alloc spelling error fixed
* the following were efficient, but didn't work, they've been made to
* work, but are no longer as efficient :-)
* bit_nclear, bit_nset, bit_ffc, bit_ffs
*/
typedef unsigned char bitstr_t;
/* internal macros */
/* byte of the bitstring bit is in */
#define _bit_byte(bit) \
((bit) >> 3)
/* mask for the bit within its byte */
#define _bit_mask(bit) \
(1 << ((bit)&0x7))
/* external macros */
/* bytes in a bitstring of nbits bits */
#define bitstr_size(nbits) \
(((nbits) + 7) >> 3)
/* allocate a bitstring */
#define bit_alloc(nbits) \
(bitstr_t *)calloc((size_t)bitstr_size(nbits), sizeof(bitstr_t))
/* allocate a bitstring on the stack */
#define bit_decl(name, nbits) \
(name)[bitstr_size(nbits)]
/* is bit N of bitstring name set? */
#define bit_test(name, bit) \
((name)[_bit_byte(bit)] & _bit_mask(bit))
/* set bit N of bitstring name */
#define bit_set(name, bit) \
(name)[_bit_byte(bit)] |= _bit_mask(bit)
/* clear bit N of bitstring name */
#define bit_clear(name, bit) \
(name)[_bit_byte(bit)] &= ~_bit_mask(bit)
/* clear bits start ... stop in bitstring */
#define bit_nclear(name, start, stop) do { \
register bitstr_t *_name = name; \
register int _start = start, _stop = stop; \
while (_start <= _stop) { \
bit_clear(_name, _start); \
_start++; \
} \
} while (0)
/* set bits start ... stop in bitstring */
#define bit_nset(name, start, stop) do { \
register bitstr_t *_name = name; \
register int _start = start, _stop = stop; \
while (_start <= _stop) { \
bit_set(_name, _start); \
_start++; \
} \
} while (0)
/* find first bit clear in name */
#define bit_ffc(name, nbits, value) do { \
register bitstr_t *_name = name; \
register int _bit, _nbits = nbits, _value = -1; \
for (_bit = 0; _bit < _nbits; ++_bit) \
if (!bit_test(_name, _bit)) { \
_value = _bit; \
break; \
} \
*(value) = _value; \
} while (0)
/* find first bit set in name */
#define bit_ffs(name, nbits, value) do { \
register bitstr_t *_name = name; \
register int _bit, _nbits = nbits, _value = -1; \
for (_bit = 0; _bit < _nbits; ++_bit) \
if (bit_test(_name, _bit)) { \
_value = _bit; \
break; \
} \
*(value) = _value; \
} while (0)
#endif /* !_BITSTRING_H_ */
|
