00001 /* 00002 * Copyright (c) 1989, 1993 00003 * The Regents of the University of California. All rights reserved. 00004 * 00005 * This code is derived from software contributed to Berkeley by 00006 * Paul Vixie. 00007 * 00008 * Redistribution and use in source and binary forms, with or without 00009 * modification, are permitted provided that the following conditions 00010 * are met: 00011 * 1. Redistributions of source code must retain the above copyright 00012 * notice, this list of conditions and the following disclaimer. 00013 * 2. Redistributions in binary form must reproduce the above copyright 00014 * notice, this list of conditions and the following disclaimer in the 00015 * documentation and/or other materials provided with the distribution. 00016 * 3. All advertising materials mentioning features or use of this software 00017 * must display the following acknowledgement: 00018 * This product includes software developed by the University of 00019 * California, Berkeley and its contributors. 00020 * 4. Neither the name of the University nor the names of its contributors 00021 * may be used to endorse or promote products derived from this software 00022 * without specific prior written permission. 00023 * 00024 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 00025 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 00026 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 00027 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 00028 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 00029 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 00030 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 00031 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 00032 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 00033 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 00034 * SUCH DAMAGE. 00035 * 00036 * $FreeBSD: src/sys/sys/bitstring.h,v 1.3 2003/06/13 19:40:13 phk Exp $ 00037 */ 00038 00039 #ifndef _SYS_BITSTRING_H_ 00040 #define _SYS_BITSTRING_H_ 00041 00042 typedef unsigned char bitstr_t; 00043 00044 /* internal macros */ 00045 /* byte of the bitstring bit is in */ 00046 #define _bit_byte(bit) \ 00047 ((bit) >> 3) 00048 00049 /* mask for the bit within its byte */ 00050 #define _bit_mask(bit) \ 00051 (1 << ((bit)&0x7)) 00052 00053 /* external macros */ 00054 /* bytes in a bitstring of nbits bits */ 00055 #define bitstr_size(nbits) \ 00056 (((nbits) + 7) >> 3) 00057 00058 /* allocate a bitstring */ 00059 #define bit_alloc(nbits) \ 00060 (bitstr_t *)calloc((size_t)bitstr_size(nbits), sizeof(bitstr_t)) 00061 00062 /* allocate a bitstring on the stack */ 00063 #define bit_decl(name, nbits) \ 00064 ((name)[bitstr_size(nbits)]) 00065 00066 /* is bit N of bitstring name set? */ 00067 #define bit_test(name, bit) \ 00068 ((name)[_bit_byte(bit)] & _bit_mask(bit)) 00069 00070 /* set bit N of bitstring name */ 00071 #define bit_set(name, bit) \ 00072 ((name)[_bit_byte(bit)] |= _bit_mask(bit)) 00073 00074 /* clear bit N of bitstring name */ 00075 #define bit_clear(name, bit) \ 00076 ((name)[_bit_byte(bit)] &= ~_bit_mask(bit)) 00077 00078 /* clear bits start ... stop in bitstring */ 00079 #define bit_nclear(name, start, stop) do { \ 00080 register bitstr_t *_name = (name); \ 00081 register int _start = (start), _stop = (stop); \ 00082 register int _startbyte = _bit_byte(_start); \ 00083 register int _stopbyte = _bit_byte(_stop); \ 00084 if (_startbyte == _stopbyte) { \ 00085 _name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) | \ 00086 (0xff << ((_stop&0x7) + 1))); \ 00087 } else { \ 00088 _name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \ 00089 while (++_startbyte < _stopbyte) \ 00090 _name[_startbyte] = 0; \ 00091 _name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \ 00092 } \ 00093 } while (0) 00094 00095 /* set bits start ... stop in bitstring */ 00096 #define bit_nset(name, start, stop) do { \ 00097 register bitstr_t *_name = (name); \ 00098 register int _start = (start), _stop = (stop); \ 00099 register int _startbyte = _bit_byte(_start); \ 00100 register int _stopbyte = _bit_byte(_stop); \ 00101 if (_startbyte == _stopbyte) { \ 00102 _name[_startbyte] |= ((0xff << (_start&0x7)) & \ 00103 (0xff >> (7 - (_stop&0x7)))); \ 00104 } else { \ 00105 _name[_startbyte] |= 0xff << ((_start)&0x7); \ 00106 while (++_startbyte < _stopbyte) \ 00107 _name[_startbyte] = 0xff; \ 00108 _name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \ 00109 } \ 00110 } while (0) 00111 00112 /* find first bit clear in name */ 00113 #define bit_ffc(name, nbits, value) do { \ 00114 register bitstr_t *_name = (name); \ 00115 register int _byte, _nbits = (nbits); \ 00116 register int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \ 00117 if (_nbits > 0) \ 00118 for (_byte = 0; _byte <= _stopbyte; ++_byte) \ 00119 if (_name[_byte] != 0xff) { \ 00120 bitstr_t _lb; \ 00121 _value = _byte << 3; \ 00122 for (_lb = _name[_byte]; (_lb&0x1); \ 00123 ++_value, _lb >>= 1); \ 00124 break; \ 00125 } \ 00126 if (_value >= nbits) \ 00127 _value = -1; \ 00128 *(value) = _value; \ 00129 } while (0) 00130 00131 /* find first bit set in name */ 00132 #define bit_ffs(name, nbits, value) do { \ 00133 register bitstr_t *_name = (name); \ 00134 register int _byte, _nbits = (nbits); \ 00135 register int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \ 00136 if (_nbits > 0) \ 00137 for (_byte = 0; _byte <= _stopbyte; ++_byte) \ 00138 if (_name[_byte]) { \ 00139 bitstr_t _lb; \ 00140 _value = _byte << 3; \ 00141 for (_lb = _name[_byte]; !(_lb&0x1); \ 00142 ++_value, _lb >>= 1); \ 00143 break; \ 00144 } \ 00145 if (_value >= nbits) \ 00146 _value = -1; \ 00147 *(value) = _value; \ 00148 } while (0) 00149 00150 #endif /* !_SYS_BITSTRING_H_ */