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