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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * $FreeBSD: src/sys/sys/bitstring.h,v 1.4 2004/04/07 04:19:48 imp Exp $ 33 */ 34 35 #ifndef _SYS_BITSTRING_H_ 36 #define _SYS_BITSTRING_H_ 37 38 typedef unsigned char bitstr_t; 39 40 /* internal macros */ 41 /* byte of the bitstring bit is in */ 42 #define _bit_byte(bit) \ 43 ((bit) >> 3) 44 45 /* mask for the bit within its byte */ 46 #define _bit_mask(bit) \ 47 (1 << ((bit)&0x7)) 48 49 /* external macros */ 50 /* bytes in a bitstring of nbits bits */ 51 #define bitstr_size(nbits) \ 52 (((nbits) + 7) >> 3) 53 54 /* allocate a bitstring */ 55 #define bit_alloc(nbits) \ 56 (bitstr_t *)calloc((size_t)bitstr_size(nbits), sizeof(bitstr_t)) 57 58 /* allocate a bitstring on the stack */ 59 #define bit_decl(name, nbits) \ 60 ((name)[bitstr_size(nbits)]) 61 62 /* is bit N of bitstring name set? */ 63 #define bit_test(name, bit) \ 64 ((name)[_bit_byte(bit)] & _bit_mask(bit)) 65 66 /* set bit N of bitstring name */ 67 #define bit_set(name, bit) \ 68 ((name)[_bit_byte(bit)] |= _bit_mask(bit)) 69 70 /* clear bit N of bitstring name */ 71 #define bit_clear(name, bit) \ 72 ((name)[_bit_byte(bit)] &= ~_bit_mask(bit)) 73 74 /* clear bits start ... stop in bitstring */ 75 #define bit_nclear(name, start, stop) do { \ 76 register bitstr_t *_name = (name); \ 77 register int _start = (start), _stop = (stop); \ 78 register int _startbyte = _bit_byte(_start); \ 79 register int _stopbyte = _bit_byte(_stop); \ 80 if (_startbyte == _stopbyte) { \ 81 _name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) | \ 82 (0xff << ((_stop&0x7) + 1))); \ 83 } else { \ 84 _name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \ 85 while (++_startbyte < _stopbyte) \ 86 _name[_startbyte] = 0; \ 87 _name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \ 88 } \ 89 } while (0) 90 91 /* set bits start ... stop in bitstring */ 92 #define bit_nset(name, start, stop) do { \ 93 register bitstr_t *_name = (name); \ 94 register int _start = (start), _stop = (stop); \ 95 register int _startbyte = _bit_byte(_start); \ 96 register int _stopbyte = _bit_byte(_stop); \ 97 if (_startbyte == _stopbyte) { \ 98 _name[_startbyte] |= ((0xff << (_start&0x7)) & \ 99 (0xff >> (7 - (_stop&0x7)))); \ 100 } else { \ 101 _name[_startbyte] |= 0xff << ((_start)&0x7); \ 102 while (++_startbyte < _stopbyte) \ 103 _name[_startbyte] = 0xff; \ 104 _name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \ 105 } \ 106 } while (0) 107 108 /* find first bit clear in name */ 109 #define bit_ffc(name, nbits, value) do { \ 110 register bitstr_t *_name = (name); \ 111 register int _byte, _nbits = (nbits); \ 112 register int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \ 113 if (_nbits > 0) \ 114 for (_byte = 0; _byte <= _stopbyte; ++_byte) \ 115 if (_name[_byte] != 0xff) { \ 116 bitstr_t _lb; \ 117 _value = _byte << 3; \ 118 for (_lb = _name[_byte]; (_lb&0x1); \ 119 ++_value, _lb >>= 1); \ 120 break; \ 121 } \ 122 if (_value >= nbits) \ 123 _value = -1; \ 124 *(value) = _value; \ 125 } while (0) 126 127 /* find first bit set in name */ 128 #define bit_ffs(name, nbits, value) do { \ 129 register bitstr_t *_name = (name); \ 130 register int _byte, _nbits = (nbits); \ 131 register int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \ 132 if (_nbits > 0) \ 133 for (_byte = 0; _byte <= _stopbyte; ++_byte) \ 134 if (_name[_byte]) { \ 135 bitstr_t _lb; \ 136 _value = _byte << 3; \ 137 for (_lb = _name[_byte]; !(_lb&0x1); \ 138 ++_value, _lb >>= 1); \ 139 break; \ 140 } \ 141 if (_value >= nbits) \ 142 _value = -1; \ 143 *(value) = _value; \ 144 } while (0) 145 146 #endif /* !_SYS_BITSTRING_H_ */ 147
Indexes created Sat Sep 20 22:09:52 GMT 2025