bitstring.h revision 299090
1139825Simp/*- 21539Srgrimes * Copyright (c) 1989, 1993 31539Srgrimes * The Regents of the University of California. All rights reserved. 41539Srgrimes * 51539Srgrimes * This code is derived from software contributed to Berkeley by 61539Srgrimes * Paul Vixie. 71539Srgrimes * 81539Srgrimes * Redistribution and use in source and binary forms, with or without 91539Srgrimes * modification, are permitted provided that the following conditions 101539Srgrimes * are met: 111539Srgrimes * 1. Redistributions of source code must retain the above copyright 121539Srgrimes * notice, this list of conditions and the following disclaimer. 131539Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 141539Srgrimes * notice, this list of conditions and the following disclaimer in the 151539Srgrimes * documentation and/or other materials provided with the distribution. 161539Srgrimes * 4. Neither the name of the University nor the names of its contributors 171539Srgrimes * may be used to endorse or promote products derived from this software 181539Srgrimes * without specific prior written permission. 191539Srgrimes * 201539Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 211539Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 221539Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 231539Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 241539Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 251539Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 261539Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 271539Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 281539Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 291539Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 301539Srgrimes * SUCH DAMAGE. 311539Srgrimes * 32299090Sasomers * Copyright (c) 2014 Spectra Logic Corporation 33299090Sasomers * All rights reserved. 34299090Sasomers * 35299090Sasomers * Redistribution and use in source and binary forms, with or without 36299090Sasomers * modification, are permitted provided that the following conditions 37299090Sasomers * are met: 38299090Sasomers * 1. Redistributions of source code must retain the above copyright 39299090Sasomers * notice, this list of conditions, and the following disclaimer, 40299090Sasomers * without modification. 41299090Sasomers * 2. Redistributions in binary form must reproduce at minimum a disclaimer 42299090Sasomers * substantially similar to the "NO WARRANTY" disclaimer below 43299090Sasomers * ("Disclaimer") and any redistribution must be conditioned upon 44299090Sasomers * including a substantially similar Disclaimer requirement for further 45299090Sasomers * binary redistribution. 46299090Sasomers * 47299090Sasomers * NO WARRANTY 48299090Sasomers * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 49299090Sasomers * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 50299090Sasomers * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR 51299090Sasomers * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 52299090Sasomers * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 53299090Sasomers * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 54299090Sasomers * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 55299090Sasomers * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 56299090Sasomers * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 57299090Sasomers * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 58299090Sasomers * POSSIBILITY OF SUCH DAMAGES. 59299090Sasomers * 6066872Sdwmalone * $FreeBSD: head/sys/sys/bitstring.h 299090 2016-05-04 22:34:11Z asomers $ 611539Srgrimes */ 62116306Sphk#ifndef _SYS_BITSTRING_H_ 63116306Sphk#define _SYS_BITSTRING_H_ 641539Srgrimes 65299090Sasomers#ifdef _KERNEL 66299090Sasomers#include <sys/libkern.h> 67299090Sasomers#include <sys/malloc.h> 68299090Sasomers#endif 691539Srgrimes 70299090Sasomerstypedef unsigned long bitstr_t; 711539Srgrimes 72299090Sasomers/*---------------------- Private Implementation Details ----------------------*/ 73299090Sasomers#define _BITSTR_MASK (~0UL) 74299090Sasomers#define _BITSTR_BITS (sizeof(bitstr_t) * 8) 751539Srgrimes 76299090Sasomers/* bitstr_t in bit string containing the bit. */ 77299090Sasomersstatic inline int 78299090Sasomers_bit_idx(int _bit) 79299090Sasomers{ 80299090Sasomers return (_bit / _BITSTR_BITS); 81299090Sasomers} 821539Srgrimes 83299090Sasomers/* bit number within bitstr_t at _bit_idx(_bit). */ 84299090Sasomersstatic inline int 85299090Sasomers_bit_offset(int _bit) 86299090Sasomers{ 87299090Sasomers return (_bit % _BITSTR_BITS); 88299090Sasomers} 891539Srgrimes 90299090Sasomers/* Mask for the bit within its long. */ 91299090Sasomersstatic inline bitstr_t 92299090Sasomers_bit_mask(int _bit) 93299090Sasomers{ 94299090Sasomers return (1UL << _bit_offset(_bit)); 95299090Sasomers} 96299090Sasomers 97299090Sasomersstatic inline bitstr_t 98299090Sasomers_bit_make_mask(int _start, int _stop) 99299090Sasomers{ 100299090Sasomers return ((_BITSTR_MASK << _bit_offset(_start)) & 101299090Sasomers (_BITSTR_MASK >> (_BITSTR_BITS - _bit_offset(_stop) - 1))); 102299090Sasomers} 103299090Sasomers 104299090Sasomers/*----------------------------- Public Interface -----------------------------*/ 105299090Sasomers/* Number of bytes consumed by a bit string of nbits bits */ 106299090Sasomers#define bitstr_size(_nbits) \ 107299090Sasomers (((_nbits) + _BITSTR_BITS - 1) / 8) 108299090Sasomers 109299090Sasomers/* Allocate a bit string initialized with no bits set. */ 110299090Sasomers#ifdef _KERNEL 111299090Sasomersstatic inline bitstr_t * 112299090Sasomersbit_alloc(int _nbits, struct malloc_type *type, int flags) 113299090Sasomers{ 114299090Sasomers return ((bitstr_t *)malloc(bitstr_size(_nbits), type, flags | M_ZERO)); 115299090Sasomers} 116299090Sasomers#else 117299090Sasomersstatic inline bitstr_t * 118299090Sasomersbit_alloc(int _nbits) 119299090Sasomers{ 120299090Sasomers return ((bitstr_t *)calloc(bitstr_size(_nbits), 1)); 121299090Sasomers} 122299090Sasomers#endif 123299090Sasomers 124299090Sasomers/* Allocate a bit string on the stack with no bits set. */ 1251539Srgrimes#define bit_decl(name, nbits) \ 126299090Sasomers ((name)[bitstr_size(nbits) / sizeof(bitstr_t)]) 1271539Srgrimes 128299090Sasomers/* Is bit N of bit string set? */ 129299090Sasomersstatic inline int 130299090Sasomersbit_test(const bitstr_t *_bitstr, int _bit) 131299090Sasomers{ 132299090Sasomers return ((_bitstr[_bit_idx(_bit)] & _bit_mask(_bit)) != 0); 133299090Sasomers} 1341539Srgrimes 135299090Sasomers/* Set bit N of bit string. */ 136299090Sasomersstatic inline void 137299090Sasomersbit_set(bitstr_t *_bitstr, int _bit) 138299090Sasomers{ 139299090Sasomers _bitstr[_bit_idx(_bit)] |= _bit_mask(_bit); 140299090Sasomers} 1411539Srgrimes 142299090Sasomers/* clear bit N of bit string name */ 143299090Sasomersstatic inline void 144299090Sasomersbit_clear(bitstr_t *_bitstr, int _bit) 145299090Sasomers{ 146299090Sasomers _bitstr[_bit_idx(_bit)] &= ~_bit_mask(_bit); 147299090Sasomers} 1481539Srgrimes 149299090Sasomers/* Set bits start ... stop inclusive in bit string. */ 150299090Sasomersstatic inline void 151299090Sasomersbit_nset(bitstr_t *_bitstr, int _start, int _stop) 152299090Sasomers{ 153299090Sasomers bitstr_t *_stopbitstr; 1541539Srgrimes 155299090Sasomers _stopbitstr = _bitstr + _bit_idx(_stop); 156299090Sasomers _bitstr += _bit_idx(_start); 1571539Srgrimes 158299090Sasomers if (_bitstr == _stopbitstr) { 159299090Sasomers *_bitstr |= _bit_make_mask(_start, _stop); 160299090Sasomers } else { 161299090Sasomers *_bitstr |= _bit_make_mask(_start, _BITSTR_BITS - 1); 162299090Sasomers while (++_bitstr < _stopbitstr) 163299090Sasomers *_bitstr = _BITSTR_MASK; 164299090Sasomers *_stopbitstr |= _bit_make_mask(0, _stop); 165299090Sasomers } 166299090Sasomers} 1671539Srgrimes 168299090Sasomers/* Clear bits start ... stop inclusive in bit string. */ 169299090Sasomersstatic inline void 170299090Sasomersbit_nclear(bitstr_t *_bitstr, int _start, int _stop) 171299090Sasomers{ 172299090Sasomers bitstr_t *_stopbitstr; 1731539Srgrimes 174299090Sasomers _stopbitstr = _bitstr + _bit_idx(_stop); 175299090Sasomers _bitstr += _bit_idx(_start); 176299090Sasomers 177299090Sasomers if (_bitstr == _stopbitstr) { 178299090Sasomers *_bitstr &= ~_bit_make_mask(_start, _stop); 179299090Sasomers } else { 180299090Sasomers *_bitstr &= ~_bit_make_mask(_start, _BITSTR_BITS - 1); 181299090Sasomers while (++_bitstr < _stopbitstr) 182299090Sasomers *_bitstr = 0; 183299090Sasomers *_stopbitstr &= ~_bit_make_mask(0, _stop); 184299090Sasomers } 185299090Sasomers} 186299090Sasomers 187299090Sasomers/* Find the first bit set in bit string at or after bit start. */ 188299090Sasomersstatic inline void 189299090Sasomersbit_ffs_at(bitstr_t *_bitstr, int _start, int _nbits, int *_result) 190299090Sasomers{ 191299090Sasomers bitstr_t *_curbitstr; 192299090Sasomers bitstr_t *_stopbitstr; 193299090Sasomers bitstr_t _test; 194299090Sasomers int _value, _offset; 195299090Sasomers 196299090Sasomers if (_nbits > 0) { 197299090Sasomers _curbitstr = _bitstr + _bit_idx(_start); 198299090Sasomers _stopbitstr = _bitstr + _bit_idx(_nbits - 1); 199299090Sasomers 200299090Sasomers _test = *_curbitstr; 201299090Sasomers if (_bit_offset(_start) != 0) 202299090Sasomers _test &= _bit_make_mask(_start, _BITSTR_BITS - 1); 203299090Sasomers while (_test == 0 && _curbitstr < _stopbitstr) 204299090Sasomers _test = *(++_curbitstr); 205299090Sasomers 206299090Sasomers _offset = ffsl(_test); 207299090Sasomers _value = ((_curbitstr - _bitstr) * _BITSTR_BITS) + _offset - 1; 208299090Sasomers if (_offset == 0 || _value >= _nbits) 209299090Sasomers _value = -1; 210299090Sasomers } else { 211299090Sasomers _value = -1; 212299090Sasomers } 213299090Sasomers *_result = _value; 214299090Sasomers} 215299090Sasomers 216299090Sasomers/* Find the first bit clear in bit string at or after bit start. */ 217299090Sasomersstatic inline void 218299090Sasomersbit_ffc_at(bitstr_t *_bitstr, int _start, int _nbits, int *_result) 219299090Sasomers{ 220299090Sasomers bitstr_t *_curbitstr; 221299090Sasomers bitstr_t *_stopbitstr; 222299090Sasomers bitstr_t _test; 223299090Sasomers int _value, _offset; 224299090Sasomers 225299090Sasomers if (_nbits > 0) { 226299090Sasomers _curbitstr = _bitstr + _bit_idx(_start); 227299090Sasomers _stopbitstr = _bitstr + _bit_idx(_nbits - 1); 228299090Sasomers 229299090Sasomers _test = *_curbitstr; 230299090Sasomers if (_bit_offset(_start) != 0) 231299090Sasomers _test |= _bit_make_mask(0, _start - 1); 232299090Sasomers while (_test == _BITSTR_MASK && _curbitstr < _stopbitstr) 233299090Sasomers _test = *(++_curbitstr); 234299090Sasomers 235299090Sasomers _offset = ffsl(~_test); 236299090Sasomers _value = ((_curbitstr - _bitstr) * _BITSTR_BITS) + _offset - 1; 237299090Sasomers if (_offset == 0 || _value >= _nbits) 238299090Sasomers _value = -1; 239299090Sasomers } else { 240299090Sasomers _value = -1; 241299090Sasomers } 242299090Sasomers *_result = _value; 243299090Sasomers} 244299090Sasomers 245299090Sasomers/* Find the first bit set in bit string. */ 246299090Sasomersstatic inline void 247299090Sasomersbit_ffs(bitstr_t *_bitstr, int _nbits, int *_result) 248299090Sasomers{ 249299090Sasomers bit_ffs_at(_bitstr, /*start*/0, _nbits, _result); 250299090Sasomers} 251299090Sasomers 252299090Sasomers/* Find the first bit clear in bit string. */ 253299090Sasomersstatic inline void 254299090Sasomersbit_ffc(bitstr_t *_bitstr, int _nbits, int *_result) 255299090Sasomers{ 256299090Sasomers bit_ffc_at(_bitstr, /*start*/0, _nbits, _result); 257299090Sasomers} 258299090Sasomers 259299090Sasomers#endif /* _SYS_BITSTRING_H_ */ 260