include/bitstring.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * Copyright (c) 1989, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  *
  27  * This code is derived from software contributed to Berkeley by
  28  * Paul Vixie.
  29  *
  30  * Redistribution and use in source and binary forms, with or without
  31  * modification, are permitted provided that the following conditions
  32  * are met:
  33  * 1. Redistributions of source code must retain the above copyright
  34  *    notice, this list of conditions and the following disclaimer.
  35  * 2. Redistributions in binary form must reproduce the above copyright
  36  *    notice, this list of conditions and the following disclaimer in the
  37  *    documentation and/or other materials provided with the distribution.
  38  * 3. All advertising materials mentioning features or use of this software
  39  *    must display the following acknowledgement:
  40  *      This product includes software developed by the University of
  41  *      California, Berkeley and its contributors.
  42  * 4. Neither the name of the University nor the names of its contributors
  43  *    may be used to endorse or promote products derived from this software
  44  *    without specific prior written permission.
  45  *
  46  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  47  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  48  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  49  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  50  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  51  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  52  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  53  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  54  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  55  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  56  * SUCH DAMAGE.
  57  *
  58  *      @(#)bitstring.h 8.1 (Berkeley) 7/19/93
  59  */
  60
  61 #ifndef _BITSTRING_H_
  62 #define _BITSTRING_H_
  63
  64 typedef unsigned char bitstr_t;
  65
  66 /* internal macros */
  67                                 /* byte of the bitstring bit is in */
  68 #define _bit_byte(bit) \
  69         ((bit) >> 3)
  70
  71                                 /* mask for the bit within its byte */
  72 #define _bit_mask(bit) \
  73         (1 << ((bit)&0x7))
  74
  75 /* external macros */
  76                                 /* bytes in a bitstring of nbits bits */
  77 #define bitstr_size(nbits) \
  78         ((((nbits) - 1) >> 3) + 1)
  79
  80                                 /* allocate a bitstring */
  81 #define bit_alloc(nbits) \
  82         (bitstr_t *)calloc(1, \
  83             (unsigned int)bitstr_size(nbits) * sizeof(bitstr_t))
  84
  85                                 /* allocate a bitstring on the stack */
  86 #define bit_decl(name, nbits) \
  87         (name)[bitstr_size(nbits)]
  88
  89                                 /* is bit N of bitstring name set? */
  90 #define bit_test(name, bit) \
  91         ((name)[_bit_byte(bit)] & _bit_mask(bit))
  92
  93                                 /* set bit N of bitstring name */
  94 #define bit_set(name, bit) \
  95         (name)[_bit_byte(bit)] |= _bit_mask(bit)
  96
  97                                 /* clear bit N of bitstring name */
  98 #define bit_clear(name, bit) \
  99         (name)[_bit_byte(bit)] &= ~_bit_mask(bit)
 100
 101                                 /* clear bits start ... stop in bitstring */
 102 #define bit_nclear(name, start, stop) { \
 103         register bitstr_t *_name = name; \
 104         register int _start = start, _stop = stop; \
 105         register int _startbyte = _bit_byte(_start); \
 106         register int _stopbyte = _bit_byte(_stop); \
 107         if (_startbyte == _stopbyte) { \
 108                 _name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) | \
 109                                       (0xff << ((_stop&0x7) + 1))); \
 110         } else { \
 111                 _name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \
 112                 while (++_startbyte < _stopbyte) \
 113                         _name[_startbyte] = 0; \
 114                 _name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \
 115         } \
 116 }
 117
 118                                 /* set bits start ... stop in bitstring */
 119 #define bit_nset(name, start, stop) { \
 120         register bitstr_t *_name = name; \
 121         register int _start = start, _stop = stop; \
 122         register int _startbyte = _bit_byte(_start); \
 123         register int _stopbyte = _bit_byte(_stop); \
 124         if (_startbyte == _stopbyte) { \
 125                 _name[_startbyte] |= ((0xff << (_start&0x7)) & \
 126                                     (0xff >> (7 - (_stop&0x7)))); \
 127         } else { \
 128                 _name[_startbyte] |= 0xff << ((_start)&0x7); \
 129                 while (++_startbyte < _stopbyte) \
 130                         _name[_startbyte] = 0xff; \
 131                 _name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \
 132         } \
 133 }
 134
 135                                 /* find first bit clear in name */
 136 #define bit_ffc(name, nbits, value) { \
 137         register bitstr_t *_name = name; \
 138         register int _byte, _nbits = nbits; \
 139         register int _stopbyte = _bit_byte(_nbits), _value = -1; \
 140         for (_byte = 0; _byte < _stopbyte; ++_byte) \
 141                 if (_name[_byte] != 0xff) { \
 142                         _value = _byte << 3; \
 143                         for (_stopbyte = _name[_byte]; (_stopbyte&0x1); \
 144                             ++_value, _stopbyte >>= 1); \
 145                         break; \
 146                 } \
 147         *(value) = _value; \
 148 }
 149
 150                                 /* find first bit set in name */
 151 #define bit_ffs(name, nbits, value) { \
 152         register bitstr_t *_name = name; \
 153         register int _byte, _nbits = nbits; \
 154         register int _stopbyte = _bit_byte(_nbits), _value = -1; \
 155         for (_byte = 0; _byte < _stopbyte; ++_byte) \
 156                 if (_name[_byte]) { \
 157                         _value = _byte << 3; \
 158                         for (_stopbyte = _name[_byte]; !(_stopbyte&0x1); \
 159                             ++_value, _stopbyte >>= 1); \
 160                         break; \
 161                 } \
 162         *(value) = _value; \
 163 }
 164
 165 #endif /* !_BITSTRING_H_ */