1 /* $OpenBSD: bitstring.h,v 1.4 2006/01/08 21:05:40 miod Exp $ */ 2 3 /* 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Paul Vixie. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)bitstring.h 8.1 (Berkeley) 7/19/93 35 */ 36 37 #ifndef _BITSTRING_H_ 38 #define _BITSTRING_H_ 39 40 typedef unsigned char bitstr_t; 41 42 /* internal macros */ 43 /* byte of the bitstring bit is in */ 44 #define _bit_byte(bit) \ 45 ((bit) >> 3) 46 47 /* mask for the bit within its byte */ 48 #define _bit_mask(bit) \ 49 (1 << ((bit)&0x7)) 50 51 /* external macros */ 52 /* bytes in a bitstring of nbits bits */ 53 #define bitstr_size(nbits) \ 54 ((((nbits) - 1) >> 3) + 1) 55 56 /* allocate a bitstring */ 57 #define bit_alloc(nbits) \ 58 (bitstr_t *)calloc(1, \ 59 (unsigned int)bitstr_size(nbits) * sizeof(bitstr_t)) 60 61 /* allocate a bitstring on the stack */ 62 #define bit_decl(name, nbits) \ 63 (name)[bitstr_size(nbits)] 64 65 /* is bit N of bitstring name set? */ 66 #define bit_test(name, bit) \ 67 ((name)[_bit_byte(bit)] & _bit_mask(bit)) 68 69 /* set bit N of bitstring name */ 70 #define bit_set(name, bit) \ 71 (name)[_bit_byte(bit)] |= _bit_mask(bit) 72 73 /* clear bit N of bitstring name */ 74 #define bit_clear(name, bit) \ 75 (name)[_bit_byte(bit)] &= ~_bit_mask(bit) 76 77 /* clear bits start ... stop in bitstring */ 78 #define bit_nclear(name, start, stop) { \ 79 register bitstr_t *_name = (name); \ 80 register int _start = (start), _stop = (stop); \ 81 register int _startbyte = _bit_byte(_start); \ 82 register int _stopbyte = _bit_byte(_stop); \ 83 if (_startbyte == _stopbyte) { \ 84 _name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) | \ 85 (0xff << ((_stop&0x7) + 1))); \ 86 } else { \ 87 _name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \ 88 while (++_startbyte < _stopbyte) \ 89 _name[_startbyte] = 0; \ 90 _name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \ 91 } \ 92 } 93 94 /* set bits start ... stop in bitstring */ 95 #define bit_nset(name, start, stop) { \ 96 register bitstr_t *_name = (name); \ 97 register int _start = (start), _stop = (stop); \ 98 register int _startbyte = _bit_byte(_start); \ 99 register int _stopbyte = _bit_byte(_stop); \ 100 if (_startbyte == _stopbyte) { \ 101 _name[_startbyte] |= ((0xff << (_start&0x7)) & \ 102 (0xff >> (7 - (_stop&0x7)))); \ 103 } else { \ 104 _name[_startbyte] |= 0xff << ((_start)&0x7); \ 105 while (++_startbyte < _stopbyte) \ 106 _name[_startbyte] = 0xff; \ 107 _name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \ 108 } \ 109 } 110 111 /* find first bit clear in name */ 112 #define bit_ffc(name, nbits, value) { \ 113 register bitstr_t *_name = (name); \ 114 register int _byte, _nbits = (nbits); \ 115 register int _stopbyte = _bit_byte(_nbits), _value = -1; \ 116 for (_byte = 0; _byte <= _stopbyte; ++_byte) \ 117 if (_name[_byte] != 0xff) { \ 118 _value = _byte << 3; \ 119 for (_stopbyte = _name[_byte]; (_stopbyte&0x1); \ 120 ++_value, _stopbyte >>= 1); \ 121 break; \ 122 } \ 123 *(value) = _value; \ 124 } 125 126 /* find first bit set in name */ 127 #define bit_ffs(name, nbits, value) { \ 128 register bitstr_t *_name = (name); \ 129 register int _byte, _nbits = (nbits); \ 130 register int _stopbyte = _bit_byte(_nbits), _value = -1; \ 131 for (_byte = 0; _byte <= _stopbyte; ++_byte) \ 132 if (_name[_byte]) { \ 133 _value = _byte << 3; \ 134 for (_stopbyte = _name[_byte]; !(_stopbyte&0x1); \ 135 ++_value, _stopbyte >>= 1); \ 136 break; \ 137 } \ 138 *(value) = _value; \ 139 } 140 141 #endif /* !_BITSTRING_H_ */ 142