1 | /* $OpenBSD: bitstring.h,v 1.5 2003/06/02 19:34:12 millert Exp $ */ |
2 | /* $NetBSD: bitstring.h,v 1.5 1997/05/14 15:49:55 pk Exp $ */ |
3 | |
4 | /* |
5 | * Copyright (c) 1989, 1993 |
6 | * The Regents of the University of California. All rights reserved. |
7 | * |
8 | * This code is derived from software contributed to Berkeley by |
9 | * Paul Vixie. |
10 | * |
11 | * Redistribution and use in source and binary forms, with or without |
12 | * modification, are permitted provided that the following conditions |
13 | * are met: |
14 | * 1. Redistributions of source code must retain the above copyright |
15 | * notice, this list of conditions and the following disclaimer. |
16 | * 2. Redistributions in binary form must reproduce the above copyright |
17 | * notice, this list of conditions and the following disclaimer in the |
18 | * documentation and/or other materials provided with the distribution. |
19 | * 3. Neither the name of the University nor the names of its contributors |
20 | * may be used to endorse or promote products derived from this software |
21 | * without specific prior written permission. |
22 | * |
23 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
24 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
25 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
26 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
27 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
28 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
29 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
30 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
31 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
32 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
33 | * SUCH DAMAGE. |
34 | * |
35 | * @(#)bitstring.h 8.1 (Berkeley) 7/19/93 |
36 | */ |
37 | |
38 | #ifndef _BITSTRING_H_ |
39 | #define _BITSTRING_H_ |
40 | |
41 | /* modified for SV/AT and bitstring bugfix by M.R.Murphy, 11oct91 |
42 | * bitstr_size changed gratuitously, but shorter |
43 | * bit_alloc spelling error fixed |
44 | * the following were efficient, but didn't work, they've been made to |
45 | * work, but are no longer as efficient :-) |
46 | * bit_nclear, bit_nset, bit_ffc, bit_ffs |
47 | */ |
48 | typedef unsigned char bitstr_t; |
49 | |
50 | /* internal macros */ |
51 | /* byte of the bitstring bit is in */ |
52 | #define _bit_byte(bit) \ |
53 | ((bit) >> 3) |
54 | |
55 | /* mask for the bit within its byte */ |
56 | #define _bit_mask(bit) \ |
57 | (1 << ((bit)&0x7)) |
58 | |
59 | /* external macros */ |
60 | /* bytes in a bitstring of nbits bits */ |
61 | #define bitstr_size(nbits) \ |
62 | (((nbits) + 7) >> 3) |
63 | |
64 | /* allocate a bitstring */ |
65 | #define bit_alloc(nbits) \ |
66 | (bitstr_t *)calloc((size_t)bitstr_size(nbits), sizeof(bitstr_t)) |
67 | |
68 | /* allocate a bitstring on the stack */ |
69 | #define bit_decl(name, nbits) \ |
70 | ((name)[bitstr_size(nbits)]) |
71 | |
72 | /* is bit N of bitstring name set? */ |
73 | #define bit_test(name, bit) \ |
74 | ((name)[_bit_byte(bit)] & _bit_mask(bit)) |
75 | |
76 | /* set bit N of bitstring name */ |
77 | #define bit_set(name, bit) \ |
78 | ((name)[_bit_byte(bit)] |= _bit_mask(bit)) |
79 | |
80 | /* clear bit N of bitstring name */ |
81 | #define bit_clear(name, bit) \ |
82 | ((name)[_bit_byte(bit)] &= ~_bit_mask(bit)) |
83 | |
84 | /* clear bits start ... stop in bitstring */ |
85 | #define bit_nclear(name, start, stop) do { \ |
86 | register bitstr_t *_name = name; \ |
87 | register int _start = start, _stop = stop; \ |
88 | while (_start <= _stop) { \ |
89 | bit_clear(_name, _start); \ |
90 | _start++; \ |
91 | } \ |
92 | } while(0) |
93 | |
94 | /* set bits start ... stop in bitstring */ |
95 | #define bit_nset(name, start, stop) do { \ |
96 | register bitstr_t *_name = name; \ |
97 | register int _start = start, _stop = stop; \ |
98 | while (_start <= _stop) { \ |
99 | bit_set(_name, _start); \ |
100 | _start++; \ |
101 | } \ |
102 | } while(0) |
103 | |
104 | /* find first bit clear in name */ |
105 | #define bit_ffc(name, nbits, value) do { \ |
106 | register bitstr_t *_name = name; \ |
107 | register int _bit, _nbits = nbits, _value = -1; \ |
108 | for (_bit = 0; _bit < _nbits; ++_bit) \ |
109 | if (!bit_test(_name, _bit)) { \ |
110 | _value = _bit; \ |
111 | break; \ |
112 | } \ |
113 | *(value) = _value; \ |
114 | } while(0) |
115 | |
116 | /* find first bit set in name */ |
117 | #define bit_ffs(name, nbits, value) do { \ |
118 | register bitstr_t *_name = name; \ |
119 | register int _bit, _nbits = nbits, _value = -1; \ |
120 | for (_bit = 0; _bit < _nbits; ++_bit) \ |
121 | if (bit_test(_name, _bit)) { \ |
122 | _value = _bit; \ |
123 | break; \ |
124 | } \ |
125 | *(value) = _value; \ |
126 | } while(0) |
127 | |
128 | #endif /* !_BITSTRING_H_ */ |
129 | |