/* $OpenBSD: bitstring.h,v 1.2 2001/01/29 01:58:46 niklas Exp $ */ /* * Copyright (c) 1989, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Paul Vixie. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)bitstring.h 8.1 (Berkeley) 7/19/93 */ #ifndef _BITSTRING_H_ #define _BITSTRING_H_ typedef unsigned char bitstr_t; /* internal macros */ /* byte of the bitstring bit is in */ #define _bit_byte(bit) \ ((bit) >> 3) /* mask for the bit within its byte */ #define _bit_mask(bit) \ (1 << ((bit)&0x7)) /* external macros */ /* bytes in a bitstring of nbits bits */ #define bitstr_size(nbits) \ ((((nbits) - 1) >> 3) + 1) /* allocate a bitstring */ #define bit_alloc(nbits) \ (bitstr_t *)calloc(1, \ (unsigned int)bitstr_size(nbits) * sizeof(bitstr_t)) /* allocate a bitstring on the stack */ #define bit_decl(name, nbits) \ (name)[bitstr_size(nbits)] /* is bit N of bitstring name set? */ #define bit_test(name, bit) \ ((name)[_bit_byte(bit)] & _bit_mask(bit)) /* set bit N of bitstring name */ #define bit_set(name, bit) \ (name)[_bit_byte(bit)] |= _bit_mask(bit) /* clear bit N of bitstring name */ #define bit_clear(name, bit) \ (name)[_bit_byte(bit)] &= ~_bit_mask(bit) /* clear bits start ... stop in bitstring */ #define bit_nclear(name, start, stop) { \ register bitstr_t *_name = name; \ register int _start = start, _stop = stop; \ register int _startbyte = _bit_byte(_start); \ register int _stopbyte = _bit_byte(_stop); \ if (_startbyte == _stopbyte) { \ _name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) | \ (0xff << ((_stop&0x7) + 1))); \ } else { \ _name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \ while (++_startbyte < _stopbyte) \ _name[_startbyte] = 0; \ _name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \ } \ } /* set bits start ... stop in bitstring */ #define bit_nset(name, start, stop) { \ register bitstr_t *_name = name; \ register int _start = start, _stop = stop; \ register int _startbyte = _bit_byte(_start); \ register int _stopbyte = _bit_byte(_stop); \ if (_startbyte == _stopbyte) { \ _name[_startbyte] |= ((0xff << (_start&0x7)) & \ (0xff >> (7 - (_stop&0x7)))); \ } else { \ _name[_startbyte] |= 0xff << ((_start)&0x7); \ while (++_startbyte < _stopbyte) \ _name[_startbyte] = 0xff; \ _name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \ } \ } /* find first bit clear in name */ #define bit_ffc(name, nbits, value) { \ register bitstr_t *_name = name; \ register int _byte, _nbits = nbits; \ register int _stopbyte = _bit_byte(_nbits), _value = -1; \ for (_byte = 0; _byte <= _stopbyte; ++_byte) \ if (_name[_byte] != 0xff) { \ _value = _byte << 3; \ for (_stopbyte = _name[_byte]; (_stopbyte&0x1); \ ++_value, _stopbyte >>= 1); \ break; \ } \ *(value) = _value; \ } /* find first bit set in name */ #define bit_ffs(name, nbits, value) { \ register bitstr_t *_name = name; \ register int _byte, _nbits = nbits; \ register int _stopbyte = _bit_byte(_nbits), _value = -1; \ for (_byte = 0; _byte <= _stopbyte; ++_byte) \ if (_name[_byte]) { \ _value = _byte << 3; \ for (_stopbyte = _name[_byte]; !(_stopbyte&0x1); \ ++_value, _stopbyte >>= 1); \ break; \ } \ *(value) = _value; \ } #endif /* !_BITSTRING_H_ */