dist/nvi/include/bitstring.h

   1 /*      $NetBSD$ */
   2
   3 /*
   4  * Copyright (c) 1989, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Paul Vixie.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by the University of
  21  *      California, Berkeley and its contributors.
  22  * 4. Neither the name of the University nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  *
  38  *      @(#)bitstring.h 8.1 (Berkeley) 7/19/93
  39  */
  40
  41 #ifndef _BITSTRING_H_
  42 #define _BITSTRING_H_
  43
  44 typedef unsigned char bitstr_t;
  45
  46 /* internal macros */
  47                                 /* byte of the bitstring bit is in */
  48 #define _bit_byte(bit) \
  49         ((bit) >> 3)
  50
  51                                 /* mask for the bit within its byte */
  52 #define _bit_mask(bit) \
  53         (1 << ((bit)&0x7))
  54
  55 /* external macros */
  56                                 /* bytes in a bitstring of nbits bits */
  57 #define bitstr_size(nbits) \
  58         ((((nbits) - 1) >> 3) + 1)
  59
  60                                 /* allocate a bitstring */
  61 #define bit_alloc(nbits) \
  62         (bitstr_t *)calloc(1, \
  63             (unsigned int)bitstr_size(nbits) * sizeof(bitstr_t))
  64
  65                                 /* allocate a bitstring on the stack */
  66 #define bit_decl(name, nbits) \
  67         (name)[bitstr_size(nbits)]
  68
  69                                 /* is bit N of bitstring name set? */
  70 #define bit_test(name, bit) \
  71         ((name)[_bit_byte(bit)] & _bit_mask(bit))
  72
  73                                 /* set bit N of bitstring name */
  74 #define bit_set(name, bit) \
  75         (name)[_bit_byte(bit)] |= _bit_mask(bit)
  76
  77                                 /* clear bit N of bitstring name */
  78 #define bit_clear(name, bit) \
  79         (name)[_bit_byte(bit)] &= ~_bit_mask(bit)
  80
  81                                 /* clear bits start ... stop in bitstring */
  82 #define bit_nclear(name, start, stop) { \
  83         register bitstr_t *_name = name; \
  84         register int _start = start, _stop = stop; \
  85         register int _startbyte = _bit_byte(_start); \
  86         register int _stopbyte = _bit_byte(_stop); \
  87         if (_startbyte == _stopbyte) { \
  88                 _name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) | \
  89                                       (0xff << ((_stop&0x7) + 1))); \
  90         } else { \
  91                 _name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \
  92                 while (++_startbyte < _stopbyte) \
  93                         _name[_startbyte] = 0; \
  94                 _name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \
  95         } \
  96 }
  97
  98                                 /* set bits start ... stop in bitstring */
  99 #define bit_nset(name, start, stop) { \
 100         register bitstr_t *_name = name; \
 101         register int _start = start, _stop = stop; \
 102         register int _startbyte = _bit_byte(_start); \
 103         register int _stopbyte = _bit_byte(_stop); \
 104         if (_startbyte == _stopbyte) { \
 105                 _name[_startbyte] |= ((0xff << (_start&0x7)) & \
 106                                     (0xff >> (7 - (_stop&0x7)))); \
 107         } else { \
 108                 _name[_startbyte] |= 0xff << ((_start)&0x7); \
 109                 while (++_startbyte < _stopbyte) \
 110                         _name[_startbyte] = 0xff; \
 111                 _name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \
 112         } \
 113 }
 114
 115                                 /* find first bit clear in name */
 116 #define bit_ffc(name, nbits, value) { \
 117         register bitstr_t *_name = name; \
 118         register int _byte, _nbits = nbits; \
 119         register int _stopbyte = _bit_byte(_nbits), _value = -1; \
 120         for (_byte = 0; _byte <= _stopbyte; ++_byte) \
 121                 if (_name[_byte] != 0xff) { \
 122                         _value = _byte << 3; \
 123                         for (_stopbyte = _name[_byte]; (_stopbyte&0x1); \
 124                             ++_value, _stopbyte >>= 1); \
 125                         break; \
 126                 } \
 127         *(value) = _value; \
 128 }
 129
 130                                 /* find first bit set in name */
 131 #define bit_ffs(name, nbits, value) { \
 132         register bitstr_t *_name = name; \
 133         register int _byte, _nbits = nbits; \
 134         register int _stopbyte = _bit_byte(_nbits), _value = -1; \
 135         for (_byte = 0; _byte <= _stopbyte; ++_byte) \
 136                 if (_name[_byte]) { \
 137                         _value = _byte << 3; \
 138                         for (_stopbyte = _name[_byte]; !(_stopbyte&0x1); \
 139                             ++_value, _stopbyte >>= 1); \
 140                         break; \
 141                 } \
 142         *(value) = _value; \
 143 }
 144
 145 #endif /* !_BITSTRING_H_ */