116 lines
3.3 KiB
C
116 lines
3.3 KiB
C
/* $NetBSD: bitstring.h,v 1.4 1994/10/26 00:55:45 cgd Exp $ */
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/*
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* Copyright (c) 1989 The Regents of the University of California.
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* All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Paul Vixie.
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*
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* Redistribution and use in source and binary forms are permitted
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* provided that the above copyright notice and this paragraph are
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* duplicated in all such forms and that any documentation,
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* advertising materials, and other materials related to such
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* distribution and use acknowledge that the software was developed
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* by the University of California, Berkeley. The name of the
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* University may not be used to endorse or promote products derived
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* from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*
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* @(#)bitstring.h 5.2 (Berkeley) 4/4/90
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*/
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#ifndef _BITSTRING_H_
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#define _BITSTRING_H_
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/* modified for SV/AT and bitstring bugfix by M.R.Murphy, 11oct91
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* bitstr_size changed gratuitously, but shorter
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* bit_alloc spelling error fixed
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* the following were efficient, but didn't work, they've been made to
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* work, but are no longer as efficient :-)
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* bit_nclear, bit_nset, bit_ffc, bit_ffs
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*/
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typedef unsigned char bitstr_t;
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/* internal macros */
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/* byte of the bitstring bit is in */
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#define _bit_byte(bit) \
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((bit) >> 3)
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/* mask for the bit within its byte */
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#define _bit_mask(bit) \
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(1 << ((bit)&0x7))
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/* external macros */
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/* bytes in a bitstring of nbits bits */
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#define bitstr_size(nbits) \
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(((nbits) + 7) >> 3)
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/* allocate a bitstring */
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#define bit_alloc(nbits) \
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(bitstr_t *)calloc((size_t)bitstr_size(nbits), sizeof(bitstr_t))
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/* allocate a bitstring on the stack */
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#define bit_decl(name, nbits) \
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(name)[bitstr_size(nbits)]
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/* is bit N of bitstring name set? */
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#define bit_test(name, bit) \
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((name)[_bit_byte(bit)] & _bit_mask(bit))
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/* set bit N of bitstring name */
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#define bit_set(name, bit) \
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(name)[_bit_byte(bit)] |= _bit_mask(bit)
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/* clear bit N of bitstring name */
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#define bit_clear(name, bit) \
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(name)[_bit_byte(bit)] &= ~_bit_mask(bit)
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/* clear bits start ... stop in bitstring */
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#define bit_nclear(name, start, stop) { \
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register bitstr_t *_name = name; \
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register int _start = start, _stop = stop; \
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while (_start <= _stop) { \
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bit_clear(_name, _start); \
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_start++; \
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} \
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}
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/* set bits start ... stop in bitstring */
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#define bit_nset(name, start, stop) { \
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register bitstr_t *_name = name; \
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register int _start = start, _stop = stop; \
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while (_start <= _stop) { \
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bit_set(_name, _start); \
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_start++; \
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} \
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}
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/* find first bit clear in name */
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#define bit_ffc(name, nbits, value) { \
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register bitstr_t *_name = name; \
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register int _bit, _nbits = nbits, _value = -1; \
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for (_bit = 0; _bit < _nbits; ++_bit) \
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if (!bit_test(_name, _bit)) { \
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_value = _bit; \
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break; \
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} \
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*(value) = _value; \
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}
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/* find first bit set in name */
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#define bit_ffs(name, nbits, value) { \
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register bitstr_t *_name = name; \
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register int _bit, _nbits = nbits, _value = -1; \
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for (_bit = 0; _bit < _nbits; ++_bit) \
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if (bit_test(_name, _bit)) { \
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_value = _bit; \
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break; \
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} \
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*(value) = _value; \
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}
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#endif /* !_BITSTRING_H_ */
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