File: [local] / src / include / bitstring.h (download)
Revision 1.3, Sun Sep 21 10:45:26 1997 UTC (26 years, 8 months ago) by niklas
Branch: MAIN
CVS Tags: OPENBSD_3_1_BASE, OPENBSD_3_1, OPENBSD_3_0_BASE, OPENBSD_3_0, OPENBSD_2_9_BASE, OPENBSD_2_9, OPENBSD_2_8_BASE, OPENBSD_2_8, OPENBSD_2_7_BASE, OPENBSD_2_7, OPENBSD_2_6_BASE, OPENBSD_2_6, OPENBSD_2_5_BASE, OPENBSD_2_5, OPENBSD_2_4_BASE, OPENBSD_2_4, OPENBSD_2_3_BASE, OPENBSD_2_3, OPENBSD_2_2_BASE, OPENBSD_2_2 Changes since 1.2: +1 -0 lines
Well, as we are heading for a release people are encouraged to rebuild their
entire trees for testing anyway, I might as well do this intrusive touching
of include files now. Added openBSD tags.
|
/* $OpenBSD: bitstring.h,v 1.3 1997/09/21 10:45:26 niklas Exp $ */
/* $NetBSD: bitstring.h,v 1.4 1994/10/26 00:55:45 cgd Exp $ */
/*
* Copyright (c) 1989 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 are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* @(#)bitstring.h 5.2 (Berkeley) 4/4/90
*/
#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
*/
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_ */