135 lines
4.4 KiB
C
135 lines
4.4 KiB
C
/* $NetBSD: bitstring.h,v 1.7 2003/08/07 09:44:09 agc 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. 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_
|
|
|
|
/* modified for SV/AT and bitstring bugfix by M.R.Murphy, 11oct91
|
|
* bitstr_size changed gratuitously, but shorter
|
|
* bit_alloc spelling error fixed
|
|
* the following were efficient, but didn't work, they've been made to
|
|
* work, but are no longer as efficient :-)
|
|
* bit_nclear, bit_nset, bit_ffc, bit_ffs
|
|
*/
|
|
/*
|
|
* The comment above may or may not bear any resemblance to reality.
|
|
* This code has been maintained in a confusing way, with little
|
|
* information available on the provenance of much of it. "At least it
|
|
* works."
|
|
* /s/ Perry E. Metzger, 2 Feb 98
|
|
*/
|
|
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) + 7) >> 3)
|
|
|
|
/* allocate a bitstring */
|
|
#define bit_alloc(nbits) \
|
|
(bitstr_t *)calloc((size_t)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) do { \
|
|
register bitstr_t *_name = name; \
|
|
register int _start = start, _stop = stop; \
|
|
while (_start <= _stop) { \
|
|
bit_clear(_name, _start); \
|
|
_start++; \
|
|
} \
|
|
} while(0)
|
|
|
|
/* set bits start ... stop in bitstring */
|
|
#define bit_nset(name, start, stop) do { \
|
|
register bitstr_t *_name = name; \
|
|
register int _start = start, _stop = stop; \
|
|
while (_start <= _stop) { \
|
|
bit_set(_name, _start); \
|
|
_start++; \
|
|
} \
|
|
} while(0)
|
|
|
|
/* find first bit clear in name */
|
|
#define bit_ffc(name, nbits, value) do { \
|
|
register bitstr_t *_name = name; \
|
|
register int _bit, _nbits = nbits, _value = -1; \
|
|
for (_bit = 0; _bit < _nbits; ++_bit) \
|
|
if (!bit_test(_name, _bit)) { \
|
|
_value = _bit; \
|
|
break; \
|
|
} \
|
|
*(value) = _value; \
|
|
} while(0)
|
|
|
|
/* find first bit set in name */
|
|
#define bit_ffs(name, nbits, value) do { \
|
|
register bitstr_t *_name = name; \
|
|
register int _bit, _nbits = nbits, _value = -1; \
|
|
for (_bit = 0; _bit < _nbits; ++_bit) \
|
|
if (bit_test(_name, _bit)) { \
|
|
_value = _bit; \
|
|
break; \
|
|
} \
|
|
*(value) = _value; \
|
|
} while(0)
|
|
|
|
#endif /* !_BITSTRING_H_ */
|