include/bitstring.h

   1 /*
   2  * Copyright (c) 1989, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Paul Vixie.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  * $FreeBSD: src/include/bitstring.h,v 1.1.1.1.14.1 2000/10/30 11:21:04 dwmalone Exp $
  37  */
  38
  39 #ifndef _BITSTRING_H_
  40 #define _BITSTRING_H_
  41
  42 typedef unsigned char bitstr_t;
  43
  44 /* internal macros */
  45                                 /* byte of the bitstring bit is in */
  46 #define _bit_byte(bit) \
  47         ((bit) >> 3)
  48
  49                                 /* mask for the bit within its byte */
  50 #define _bit_mask(bit) \
  51         (1 << ((bit)&0x7))
  52
  53 /* external macros */
  54                                 /* bytes in a bitstring of nbits bits */
  55 #define bitstr_size(nbits) \
  56         (((nbits) + 7) >> 3)
  57
  58                                 /* allocate a bitstring */
  59 #define bit_alloc(nbits) \
  60         (bitstr_t *)calloc((size_t)bitstr_size(nbits), sizeof(bitstr_t))
  61
  62                                 /* allocate a bitstring on the stack */
  63 #define bit_decl(name, nbits) \
  64         ((name)[bitstr_size(nbits)])
  65
  66                                 /* is bit N of bitstring name set? */
  67 #define bit_test(name, bit) \
  68         ((name)[_bit_byte(bit)] & _bit_mask(bit))
  69
  70                                 /* set bit N of bitstring name */
  71 #define bit_set(name, bit) \
  72         ((name)[_bit_byte(bit)] |= _bit_mask(bit))
  73
  74                                 /* clear bit N of bitstring name */
  75 #define bit_clear(name, bit) \
  76         ((name)[_bit_byte(bit)] &= ~_bit_mask(bit))
  77
  78                                 /* clear bits start ... stop in bitstring */
  79 #define bit_nclear(name, start, stop) do { \
  80         bitstr_t *_name = (name); \
  81         int _start = (start), _stop = (stop); \
  82         int _startbyte = _bit_byte(_start); \
  83         int _stopbyte = _bit_byte(_stop); \
  84         if (_startbyte == _stopbyte) { \
  85                 _name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) | \
  86                                       (0xff << ((_stop&0x7) + 1))); \
  87         } else { \
  88                 _name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \
  89                 while (++_startbyte < _stopbyte) \
  90                         _name[_startbyte] = 0; \
  91                 _name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \
  92         } \
  93 } while (0)
  94
  95                                 /* set bits start ... stop in bitstring */
  96 #define bit_nset(name, start, stop) do { \
  97         bitstr_t *_name = (name); \
  98         int _start = (start), _stop = (stop); \
  99         int _startbyte = _bit_byte(_start); \
 100         int _stopbyte = _bit_byte(_stop); \
 101         if (_startbyte == _stopbyte) { \
 102                 _name[_startbyte] |= ((0xff << (_start&0x7)) & \
 103                                     (0xff >> (7 - (_stop&0x7)))); \
 104         } else { \
 105                 _name[_startbyte] |= 0xff << ((_start)&0x7); \
 106                 while (++_startbyte < _stopbyte) \
 107                         _name[_startbyte] = 0xff; \
 108                 _name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \
 109         } \
 110 } while (0)
 111
 112                                 /* find first bit clear in name */
 113 #define bit_ffc(name, nbits, value) do { \
 114         bitstr_t *_name = (name); \
 115         int _byte, _nbits = (nbits); \
 116         int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \
 117         if (_nbits > 0) \
 118                 for (_byte = 0; _byte <= _stopbyte; ++_byte) \
 119                         if (_name[_byte] != 0xff) { \
 120                                 bitstr_t _lb; \
 121                                 _value = _byte << 3; \
 122                                 for (_lb = _name[_byte]; (_lb&0x1); \
 123                                     ++_value, _lb >>= 1); \
 124                                 break; \
 125                         } \
 126         if (_value >= nbits) \
 127                 _value = -1; \
 128         *(value) = _value; \
 129 } while (0)
 130
 131                                 /* find first bit set in name */
 132 #define bit_ffs(name, nbits, value) do { \
 133         bitstr_t *_name = (name); \
 134         int _byte, _nbits = (nbits); \
 135         int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \
 136         if (_nbits > 0) \
 137                 for (_byte = 0; _byte <= _stopbyte; ++_byte) \
 138                         if (_name[_byte]) { \
 139                                 bitstr_t _lb; \
 140                                 _value = _byte << 3; \
 141                                 for (_lb = _name[_byte]; !(_lb&0x1); \
 142                                     ++_value, _lb >>= 1); \
 143                                 break; \
 144                         } \
 145         if (_value >= nbits) \
 146                 _value = -1; \
 147         *(value) = _value; \
 148 } while (0)
 149
 150                                 /* find last bit set in name */
 151 #define bit_fls(name, nbits, value) do { \
 152         bitstr_t *_name = (name); \
 153         int _byte, _nbits = (nbits); \
 154         int _startbyte = _bit_byte(_nbits - 1), _value = -1; \
 155         if (_nbits > 0) \
 156                 for (_byte = _startbyte; _byte >= 0; --_byte) \
 157                         if (_name[_byte]) { \
 158                                 bitstr_t _lb; \
 159                                 _value = _byte << 3; \
 160                                 for (_lb = _name[_byte]; _lb != 0x1; \
 161                                     ++_value, _lb >>= 1); \
 162                                 break; \
 163                         } \
 164         if (_value >= nbits) \
 165                 _value = -1; \
 166         *(value) = _value; \
 167 } while (0)
 168
 169                                 /* find clear range of length len */
 170 #define bit_nsearch(name, nbits, value, len) do { \
 171         bitstr_t *_name = (name); \
 172         int _nbits = (nbits); \
 173         int *_value = (value); \
 174         int _len = (len); \
 175         int _bit, _bit0 = -1; \
 176         int _tmplen = _len; \
 177         int _match = 0; \
 178         *(_value) = -1; \
 179         for (_bit = 0; _bit < _nbits && _tmplen > 0; _bit++) { \
 180                 if (_match == 0) { \
 181                         if (bit_test((_name), _bit) == 0) { \
 182                                 _match = 1; \
 183                                 _tmplen--; \
 184                                 _bit0 = _bit; \
 185                         } \
 186                 } else { \
 187                         if (bit_test((_name), _bit) == 0) { \
 188                                 _tmplen--; \
 189                         } else { \
 190                                 _match = 0; \
 191                                 _tmplen = _len; \
 192                         } \
 193                 } \
 194         } \
 195         if (_tmplen == 0) \
 196                 *(_value) = _bit0; \
 197 } while (0)
 198
 199 #endif /* !_BITSTRING_H_ */