include/bitstring.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Copyright (c) 1989, 1993
  27  *      The Regents of the University of California.  All rights reserved.
  28  *
  29  * This code is derived from software contributed to Berkeley by
  30  * Paul Vixie.
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions
  34  * are met:
  35  * 1. Redistributions of source code must retain the above copyright
  36  *    notice, this list of conditions and the following disclaimer.
  37  * 2. Redistributions in binary form must reproduce the above copyright
  38  *    notice, this list of conditions and the following disclaimer in the
  39  *    documentation and/or other materials provided with the distribution.
  40  * 3. All advertising materials mentioning features or use of this software
  41  *    must display the following acknowledgement:
  42  *      This product includes software developed by the University of
  43  *      California, Berkeley and its contributors.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)bitstring.h 8.1 (Berkeley) 7/19/93
  61  */
  62
  63 #ifndef _BITSTRING_H_
  64 #define _BITSTRING_H_
  65
  66 typedef unsigned char bitstr_t;
  67
  68 /* internal macros */
  69                                 /* byte of the bitstring bit is in */
  70 #define _bit_byte(bit) \
  71         ((bit) >> 3)
  72
  73                                 /* mask for the bit within its byte */
  74 #define _bit_mask(bit) \
  75         (1 << ((bit)&0x7))
  76
  77 /* external macros */
  78                                 /* bytes in a bitstring of nbits bits */
  79 #define bitstr_size(nbits) \
  80         ((((nbits) - 1) >> 3) + 1)
  81
  82                                 /* allocate a bitstring */
  83 #define bit_alloc(nbits) \
  84         (bitstr_t *)calloc(1, \
  85             (unsigned int)bitstr_size(nbits) * sizeof(bitstr_t))
  86
  87                                 /* allocate a bitstring on the stack */
  88 #define bit_decl(name, nbits) \
  89         (name)[bitstr_size(nbits)]
  90
  91                                 /* is bit N of bitstring name set? */
  92 #define bit_test(name, bit) \
  93         ((name)[_bit_byte(bit)] & _bit_mask(bit))
  94
  95                                 /* set bit N of bitstring name */
  96 #define bit_set(name, bit) \
  97         (name)[_bit_byte(bit)] |= _bit_mask(bit)
  98
  99                                 /* clear bit N of bitstring name */
 100 #define bit_clear(name, bit) \
 101         (name)[_bit_byte(bit)] &= ~_bit_mask(bit)
 102
 103                                 /* clear bits start ... stop in bitstring */
 104 #define bit_nclear(name, start, stop) { \
 105         register bitstr_t *_name = name; \
 106         register int _start = start, _stop = stop; \
 107         register int _startbyte = _bit_byte(_start); \
 108         register int _stopbyte = _bit_byte(_stop); \
 109         if (_startbyte == _stopbyte) { \
 110                 _name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) | \
 111                                       (0xff << ((_stop&0x7) + 1))); \
 112         } else { \
 113                 _name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \
 114                 while (++_startbyte < _stopbyte) \
 115                         _name[_startbyte] = 0; \
 116                 _name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \
 117         } \
 118 }
 119
 120                                 /* set bits start ... stop in bitstring */
 121 #define bit_nset(name, start, stop) { \
 122         register bitstr_t *_name = name; \
 123         register int _start = start, _stop = stop; \
 124         register int _startbyte = _bit_byte(_start); \
 125         register int _stopbyte = _bit_byte(_stop); \
 126         if (_startbyte == _stopbyte) { \
 127                 _name[_startbyte] |= ((0xff << (_start&0x7)) & \
 128                                     (0xff >> (7 - (_stop&0x7)))); \
 129         } else { \
 130                 _name[_startbyte] |= 0xff << ((_start)&0x7); \
 131                 while (++_startbyte < _stopbyte) \
 132                         _name[_startbyte] = 0xff; \
 133                 _name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \
 134         } \
 135 }
 136
 137                                 /* find first bit clear in name */
 138 #define bit_ffc(name, nbits, value) { \
 139         register bitstr_t *_name = name; \
 140         register int _byte, _nbits = nbits; \
 141         register int _stopbyte = _bit_byte(_nbits), _value = -1; \
 142         for (_byte = 0; _byte < _stopbyte; ++_byte) \
 143                 if (_name[_byte] != 0xff) { \
 144                         _value = _byte << 3; \
 145                         for (_stopbyte = _name[_byte]; (_stopbyte&0x1); \
 146                             ++_value, _stopbyte >>= 1); \
 147                         break; \
 148                 } \
 149         *(value) = _value; \
 150 }
 151
 152                                 /* find first bit set in name */
 153 #define bit_ffs(name, nbits, value) { \
 154         register bitstr_t *_name = name; \
 155         register int _byte, _nbits = nbits; \
 156         register int _stopbyte = _bit_byte(_nbits), _value = -1; \
 157         for (_byte = 0; _byte < _stopbyte; ++_byte) \
 158                 if (_name[_byte]) { \
 159                         _value = _byte << 3; \
 160                         for (_stopbyte = _name[_byte]; !(_stopbyte&0x1); \
 161                             ++_value, _stopbyte >>= 1); \
 162                         break; \
 163                 } \
 164         *(value) = _value; \
 165 }
 166
 167 #endif /* !_BITSTRING_H_ */