bsd/include/bitstring.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1989, 1993
  24  *      The Regents of the University of California.  All rights reserved.
  25  *
  26  * This code is derived from software contributed to Berkeley by
  27  * Paul Vixie.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 3. All advertising materials mentioning features or use of this software
  38  *    must display the following acknowledgement:
  39  *      This product includes software developed by the University of
  40  *      California, Berkeley and its contributors.
  41  * 4. Neither the name of the University nor the names of its contributors
  42  *    may be used to endorse or promote products derived from this software
  43  *    without specific prior written permission.
  44  *
  45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  55  * SUCH DAMAGE.
  56  *
  57  *      @(#)bitstring.h 8.1 (Berkeley) 7/19/93
  58  */
  59
  60 #ifndef _BITSTRING_H_
  61 #define _BITSTRING_H_
  62
  63 typedef unsigned char bitstr_t;
  64
  65 /* internal macros */
  66                                 /* byte of the bitstring bit is in */
  67 #define _bit_byte(bit) \
  68         ((bit) >> 3)
  69
  70                                 /* mask for the bit within its byte */
  71 #define _bit_mask(bit) \
  72         (1 << ((bit)&0x7))
  73
  74 /* external macros */
  75                                 /* bytes in a bitstring of nbits bits */
  76 #define bitstr_size(nbits) \
  77         ((((nbits) - 1) >> 3) + 1)
  78
  79                                 /* allocate a bitstring */
  80 #define bit_alloc(nbits) \
  81         (bitstr_t *)calloc(1, \
  82             (unsigned int)bitstr_size(nbits) * sizeof(bitstr_t))
  83
  84                                 /* allocate a bitstring on the stack */
  85 #define bit_decl(name, nbits) \
  86         (name)[bitstr_size(nbits)]
  87
  88                                 /* is bit N of bitstring name set? */
  89 #define bit_test(name, bit) \
  90         ((name)[_bit_byte(bit)] & _bit_mask(bit))
  91
  92                                 /* set bit N of bitstring name */
  93 #define bit_set(name, bit) \
  94         (name)[_bit_byte(bit)] |= _bit_mask(bit)
  95
  96                                 /* clear bit N of bitstring name */
  97 #define bit_clear(name, bit) \
  98         (name)[_bit_byte(bit)] &= ~_bit_mask(bit)
  99
 100                                 /* clear bits start ... stop in bitstring */
 101 #define bit_nclear(name, start, stop) { \
 102         register bitstr_t *_name = name; \
 103         register int _start = start, _stop = stop; \
 104         register int _startbyte = _bit_byte(_start); \
 105         register int _stopbyte = _bit_byte(_stop); \
 106         if (_startbyte == _stopbyte) { \
 107                 _name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) | \
 108                                       (0xff << ((_stop&0x7) + 1))); \
 109         } else { \
 110                 _name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \
 111                 while (++_startbyte < _stopbyte) \
 112                         _name[_startbyte] = 0; \
 113                 _name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \
 114         } \
 115 }
 116
 117                                 /* set bits start ... stop in bitstring */
 118 #define bit_nset(name, start, stop) { \
 119         register bitstr_t *_name = name; \
 120         register int _start = start, _stop = stop; \
 121         register int _startbyte = _bit_byte(_start); \
 122         register int _stopbyte = _bit_byte(_stop); \
 123         if (_startbyte == _stopbyte) { \
 124                 _name[_startbyte] |= ((0xff << (_start&0x7)) & \
 125                                     (0xff >> (7 - (_stop&0x7)))); \
 126         } else { \
 127                 _name[_startbyte] |= 0xff << ((_start)&0x7); \
 128                 while (++_startbyte < _stopbyte) \
 129                         _name[_startbyte] = 0xff; \
 130                 _name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \
 131         } \
 132 }
 133
 134                                 /* find first bit clear in name */
 135 #define bit_ffc(name, nbits, value) { \
 136         register bitstr_t *_name = name; \
 137         register int _byte, _nbits = nbits; \
 138         register int _stopbyte = _bit_byte(_nbits), _value = -1; \
 139         for (_byte = 0; _byte <= _stopbyte; ++_byte) \
 140                 if (_name[_byte] != 0xff) { \
 141                         _value = _byte << 3; \
 142                         for (_stopbyte = _name[_byte]; (_stopbyte&0x1); \
 143                             ++_value, _stopbyte >>= 1); \
 144                         break; \
 145                 } \
 146         *(value) = _value; \
 147 }
 148
 149                                 /* find first bit set in name */
 150 #define bit_ffs(name, nbits, value) { \
 151         register bitstr_t *_name = name; \
 152         register int _byte, _nbits = nbits; \
 153         register int _stopbyte = _bit_byte(_nbits), _value = -1; \
 154         for (_byte = 0; _byte <= _stopbyte; ++_byte) \
 155                 if (_name[_byte]) { \
 156                         _value = _byte << 3; \
 157                         for (_stopbyte = _name[_byte]; !(_stopbyte&0x1); \
 158                             ++_value, _stopbyte >>= 1); \
 159                         break; \
 160                 } \
 161         *(value) = _value; \
 162 }
 163
 164 #endif /* !_BITSTRING_H_ */