| 1 | /* |
| 2 | * Copyright (c) 1989 The Regents of the University of California. |
| 3 | * 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 | * @(#)bitstring.h 5.5 (Berkeley) 4/3/91 |
| 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) - 1) >> 3) + 1) |
| 57 | |
| 58 | /* allocate a bitstring */ |
| 59 | #define bit_alloc(nbits) \ |
| 60 | (bitstr_t *)calloc(1, \ |
| 61 | (unsigned int)_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) { \ |
| 81 | register bitstr_t *_name = name; \ |
| 82 | register int _start = start, _stop = stop; \ |
| 83 | register int _startbyte = _bit_byte(_start); \ |
| 84 | register int _stopbyte = _bit_byte(_stop); \ |
| 85 | _name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \ |
| 86 | while (++_startbyte < _stopbyte) \ |
| 87 | _name[_startbyte] = 0; \ |
| 88 | _name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \ |
| 89 | } |
| 90 | |
| 91 | /* set bits start ... stop in bitstring */ |
| 92 | #define bit_nset(name, start, stop) { \ |
| 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 | _name[_startbyte] |= 0xff << ((start)&0x7); \ |
| 98 | while (++_startbyte < _stopbyte) \ |
| 99 | _name[_startbyte] = 0xff; \ |
| 100 | _name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \ |
| 101 | } |
| 102 | |
| 103 | /* find first bit clear in name */ |
| 104 | #define bit_ffc(name, nbits, value) { \ |
| 105 | register bitstr_t *_name = name; \ |
| 106 | register int _byte, _nbits = nbits; \ |
| 107 | register int _stopbyte = _bit_byte(_nbits), _value = -1; \ |
| 108 | for (_byte = 0; _byte <= _stopbyte; ++_byte) \ |
| 109 | if (_name[_byte] != 0xff) { \ |
| 110 | _value = _byte << 3; \ |
| 111 | for (_stopbyte = _name[_byte]; (_stopbyte&0x1); \ |
| 112 | ++_value, _stopbyte >>= 1); \ |
| 113 | break; \ |
| 114 | } \ |
| 115 | *(value) = _value; \ |
| 116 | } |
| 117 | |
| 118 | /* find first bit set in name */ |
| 119 | #define bit_ffs(name, nbits, value) { \ |
| 120 | register bitstr_t *_name = name; \ |
| 121 | register int _byte, _nbits = nbits; \ |
| 122 | register int _stopbyte = _bit_byte(_nbits), _value = -1; \ |
| 123 | for (_byte = 0; _byte <= _stopbyte; ++_byte) \ |
| 124 | if (_name[_byte]) { \ |
| 125 | _value = _byte << 3; \ |
| 126 | for (_stopbyte = _name[_byte]; !(_stopbyte&0x1); \ |
| 127 | ++_value, _stopbyte >>= 1); \ |
| 128 | break; \ |
| 129 | } \ |
| 130 | *(value) = _value; \ |
| 131 | } |
| 132 | |
| 133 | #endif /* !_BITSTRING_H_ */ |