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 * $DragonFly: src/include/bitstring.h,v 1.3 2007/04/18 18:39:11 swildner Exp $ 38 */ 39 40 #ifndef _BITSTRING_H_ 41 #define _BITSTRING_H_ 42 43 typedef unsigned char bitstr_t; 44 45 /* internal macros */ 46 /* byte of the bitstring bit is in */ 47 #define _bit_byte(bit) \ 48 ((bit) >> 3) 49 50 /* mask for the bit within its byte */ 51 #define _bit_mask(bit) \ 52 (1 << ((bit)&0x7)) 53 54 /* external macros */ 55 /* bytes in a bitstring of nbits bits */ 56 #define bitstr_size(nbits) \ 57 (((nbits) + 7) >> 3) 58 59 /* allocate a bitstring */ 60 #define bit_alloc(nbits) \ 61 (bitstr_t *)calloc((size_t)bitstr_size(nbits), sizeof(bitstr_t)) 62 63 /* allocate a bitstring on the stack */ 64 #define bit_decl(name, nbits) \ 65 ((name)[bitstr_size(nbits)]) 66 67 /* is bit N of bitstring name set? */ 68 #define bit_test(name, bit) \ 69 ((name)[_bit_byte(bit)] & _bit_mask(bit)) 70 71 /* set bit N of bitstring name */ 72 #define bit_set(name, bit) \ 73 ((name)[_bit_byte(bit)] |= _bit_mask(bit)) 74 75 /* clear bit N of bitstring name */ 76 #define bit_clear(name, bit) \ 77 ((name)[_bit_byte(bit)] &= ~_bit_mask(bit)) 78 79 /* clear bits start ... stop in bitstring */ 80 #define bit_nclear(name, start, stop) do { \ 81 bitstr_t *_name = (name); \ 82 int _start = (start), _stop = (stop); \ 83 int _startbyte = _bit_byte(_start); \ 84 int _stopbyte = _bit_byte(_stop); \ 85 if (_startbyte == _stopbyte) { \ 86 _name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) | \ 87 (0xff << ((_stop&0x7) + 1))); \ 88 } else { \ 89 _name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \ 90 while (++_startbyte < _stopbyte) \ 91 _name[_startbyte] = 0; \ 92 _name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \ 93 } \ 94 } while (0) 95 96 /* set bits start ... stop in bitstring */ 97 #define bit_nset(name, start, stop) do { \ 98 bitstr_t *_name = (name); \ 99 int _start = (start), _stop = (stop); \ 100 int _startbyte = _bit_byte(_start); \ 101 int _stopbyte = _bit_byte(_stop); \ 102 if (_startbyte == _stopbyte) { \ 103 _name[_startbyte] |= ((0xff << (_start&0x7)) & \ 104 (0xff >> (7 - (_stop&0x7)))); \ 105 } else { \ 106 _name[_startbyte] |= 0xff << ((_start)&0x7); \ 107 while (++_startbyte < _stopbyte) \ 108 _name[_startbyte] = 0xff; \ 109 _name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \ 110 } \ 111 } while (0) 112 113 /* find first bit clear in name */ 114 #define bit_ffc(name, nbits, value) do { \ 115 bitstr_t *_name = (name); \ 116 int _byte, _nbits = (nbits); \ 117 int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \ 118 if (_nbits > 0) \ 119 for (_byte = 0; _byte <= _stopbyte; ++_byte) \ 120 if (_name[_byte] != 0xff) { \ 121 bitstr_t _lb; \ 122 _value = _byte << 3; \ 123 for (_lb = _name[_byte]; (_lb&0x1); \ 124 ++_value, _lb >>= 1); \ 125 break; \ 126 } \ 127 if (_value >= nbits) \ 128 _value = -1; \ 129 *(value) = _value; \ 130 } while (0) 131 132 /* find first bit set in name */ 133 #define bit_ffs(name, nbits, value) do { \ 134 bitstr_t *_name = (name); \ 135 int _byte, _nbits = (nbits); \ 136 int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \ 137 if (_nbits > 0) \ 138 for (_byte = 0; _byte <= _stopbyte; ++_byte) \ 139 if (_name[_byte]) { \ 140 bitstr_t _lb; \ 141 _value = _byte << 3; \ 142 for (_lb = _name[_byte]; !(_lb&0x1); \ 143 ++_value, _lb >>= 1); \ 144 break; \ 145 } \ 146 if (_value >= nbits) \ 147 _value = -1; \ 148 *(value) = _value; \ 149 } while (0) 150 151 #define _fls(mask, value) do { \ 152 int _fmask = (mask); \ 153 int *_value = (value); \ 154 int _bit = 0; \ 155 if (_fmask == 0) { \ 156 *(_value) = 0; \ 157 break; \ 158 } \ 159 for (_bit = 1; _fmask != 1; _bit++) \ 160 _fmask = (unsigned char) _fmask >> 1; \ 161 *(_value) = _bit; \ 162 } while (0) 163 164 /* find last bit set in name */ 165 #define bit_fls(name, nbits, value) do { \ 166 bitstr_t *_name = (name); \ 167 int _nbits = (nbits); \ 168 int _byte = _bit_byte(_nbits - 1); \ 169 int *_value = (value); \ 170 int _mask = 0;\ 171 if (_nbits > 0) \ 172 for (; _byte >= 0; _byte--) { \ 173 if (!_name[_byte]) \ 174 continue; \ 175 _fls(_name[_byte], &_mask); \ 176 break; \ 177 } \ 178 *(_value) = (_mask * (_byte + 1)) - 1; \ 179 } while (0) 180 181 /* find clear range of length len */ 182 #define bit_nsearch(name, nbits, value, len) do { \ 183 bitstr_t *_name = (name); \ 184 int _nbits = (nbits); \ 185 int *_value = (value); \ 186 int _len = (len); \ 187 int _bit, _bit0; \ 188 int _tmplen = _len; \ 189 int _match = 0; \ 190 *(_value) = -1; \ 191 for (_bit = 0; _bit < _nbits; _bit++) { \ 192 if (_match == 0) { \ 193 if (bit_test((_name), _bit) == 0) { \ 194 _match = 1; \ 195 _tmplen--; \ 196 _bit0 = _bit; \ 197 } else { \ 198 continue; \ 199 } \ 200 } else { \ 201 if (_tmplen >= 0) { \ 202 if (bit_test((_name), _bit) == 0) { \ 203 _tmplen--; \ 204 } else { \ 205 _match = 0; \ 206 _tmplen = _len; \ 207 continue; \ 208 } \ 209 } else { \ 210 *(_value) = _bit0; \ 211 } \ 212 } \ 213 } \ 214 } while (0) 215 216 #endif /* !_BITSTRING_H_ */ 217