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 * $FreeBSD$ 37 */ 38 39 #ifndef _BITSTRING_H_ 40 #define _BITSTRING_H_ 41 42 typedef unsigned char bitstr_t; 43 44 /* internal macros */ 45 /* byte of the bitstring bit is in */ 46 #define _bit_byte(bit) \ 47 ((bit) >> 3) 48 49 /* mask for the bit within its byte */ 50 #define _bit_mask(bit) \ 51 (1 << ((bit)&0x7)) 52 53 /* external macros */ 54 /* bytes in a bitstring of nbits bits */ 55 #define bitstr_size(nbits) \ 56 (((nbits) + 7) >> 3) 57 58 /* allocate a bitstring */ 59 #define bit_alloc(nbits) \ 60 (bitstr_t *)calloc((size_t)bitstr_size(nbits), sizeof(bitstr_t)) 61 62 /* allocate a bitstring on the stack */ 63 #define bit_decl(name, nbits) \ 64 ((name)[bitstr_size(nbits)]) 65 66 /* is bit N of bitstring name set? */ 67 #define bit_test(name, bit) \ 68 ((name)[_bit_byte(bit)] & _bit_mask(bit)) 69 70 /* set bit N of bitstring name */ 71 #define bit_set(name, bit) \ 72 ((name)[_bit_byte(bit)] |= _bit_mask(bit)) 73 74 /* clear bit N of bitstring name */ 75 #define bit_clear(name, bit) \ 76 ((name)[_bit_byte(bit)] &= ~_bit_mask(bit)) 77 78 /* clear bits start ... stop in bitstring */ 79 #define bit_nclear(name, start, stop) do { \ 80 register bitstr_t *_name = (name); \ 81 register int _start = (start), _stop = (stop); \ 82 register int _startbyte = _bit_byte(_start); \ 83 register int _stopbyte = _bit_byte(_stop); \ 84 if (_startbyte == _stopbyte) { \ 85 _name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) | \ 86 (0xff << ((_stop&0x7) + 1))); \ 87 } else { \ 88 _name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \ 89 while (++_startbyte < _stopbyte) \ 90 _name[_startbyte] = 0; \ 91 _name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \ 92 } \ 93 } while (0) 94 95 /* set bits start ... stop in bitstring */ 96 #define bit_nset(name, start, stop) do { \ 97 register bitstr_t *_name = (name); \ 98 register int _start = (start), _stop = (stop); \ 99 register int _startbyte = _bit_byte(_start); \ 100 register int _stopbyte = _bit_byte(_stop); \ 101 if (_startbyte == _stopbyte) { \ 102 _name[_startbyte] |= ((0xff << (_start&0x7)) & \ 103 (0xff >> (7 - (_stop&0x7)))); \ 104 } else { \ 105 _name[_startbyte] |= 0xff << ((_start)&0x7); \ 106 while (++_startbyte < _stopbyte) \ 107 _name[_startbyte] = 0xff; \ 108 _name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \ 109 } \ 110 } while (0) 111 112 /* find first bit clear in name */ 113 #define bit_ffc(name, nbits, value) do { \ 114 register bitstr_t *_name = (name); \ 115 register int _byte, _nbits = (nbits); \ 116 register int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \ 117 if (_nbits > 0) \ 118 for (_byte = 0; _byte <= _stopbyte; ++_byte) \ 119 if (_name[_byte] != 0xff) { \ 120 bitstr_t _lb; \ 121 _value = _byte << 3; \ 122 for (_lb = _name[_byte]; (_lb&0x1); \ 123 ++_value, _lb >>= 1); \ 124 break; \ 125 } \ 126 if (_value >= nbits) \ 127 _value = -1; \ 128 *(value) = _value; \ 129 } while (0) 130 131 /* find first bit set in name */ 132 #define bit_ffs(name, nbits, value) do { \ 133 register bitstr_t *_name = (name); \ 134 register int _byte, _nbits = (nbits); \ 135 register int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \ 136 if (_nbits > 0) \ 137 for (_byte = 0; _byte <= _stopbyte; ++_byte) \ 138 if (_name[_byte]) { \ 139 bitstr_t _lb; \ 140 _value = _byte << 3; \ 141 for (_lb = _name[_byte]; !(_lb&0x1); \ 142 ++_value, _lb >>= 1); \ 143 break; \ 144 } \ 145 if (_value >= nbits) \ 146 _value = -1; \ 147 *(value) = _value; \ 148 } while (0) 149 150 #endif /* !_BITSTRING_H_ */ 151