[apple/libc.git] / include / bitstring.h

/*
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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.
 *
 * $FreeBSD$
 */

#ifndef _BITSTRING_H_
#define	_BITSTRING_H_

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 { \
	bitstr_t *_name = (name); \
	int _start = (start), _stop = (stop); \
	int _startbyte = _bit_byte(_start); \
	int _stopbyte = _bit_byte(_stop); \
	if (_startbyte == _stopbyte) { \
		_name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) | \
				      (0xff << ((_stop&0x7) + 1))); \
	} else { \
		_name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \
		while (++_startbyte < _stopbyte) \
			_name[_startbyte] = 0; \
		_name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \
	} \
} while (0)

				/* set bits start ... stop in bitstring */
#define	bit_nset(name, start, stop) do { \
	bitstr_t *_name = (name); \
	int _start = (start), _stop = (stop); \
	int _startbyte = _bit_byte(_start); \
	int _stopbyte = _bit_byte(_stop); \
	if (_startbyte == _stopbyte) { \
		_name[_startbyte] |= ((0xff << (_start&0x7)) & \
				    (0xff >> (7 - (_stop&0x7)))); \
	} else { \
		_name[_startbyte] |= 0xff << ((_start)&0x7); \
		while (++_startbyte < _stopbyte) \
	    		_name[_startbyte] = 0xff; \
		_name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \
	} \
} while (0)

				/* find first bit clear in name */
#define	bit_ffc(name, nbits, value) do { \
	bitstr_t *_name = (name); \
	int _byte, _nbits = (nbits); \
	int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \
	if (_nbits > 0) \
		for (_byte = 0; _byte <= _stopbyte; ++_byte) \
			if (_name[_byte] != 0xff) { \
				bitstr_t _lb; \
				_value = _byte << 3; \
				for (_lb = _name[_byte]; (_lb&0x1); \
				    ++_value, _lb >>= 1); \
				break; \
			} \
	if (_value >= nbits) \
		_value = -1; \
	*(value) = _value; \
} while (0)

				/* find first bit set in name */
#define	bit_ffs(name, nbits, value) do { \
	bitstr_t *_name = (name); \
	int _byte, _nbits = (nbits); \
	int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \
	if (_nbits > 0) \
		for (_byte = 0; _byte <= _stopbyte; ++_byte) \
			if (_name[_byte]) { \
				bitstr_t _lb; \
				_value = _byte << 3; \
				for (_lb = _name[_byte]; !(_lb&0x1); \
				    ++_value, _lb >>= 1); \
				break; \
			} \
	if (_value >= nbits) \
		_value = -1; \
	*(value) = _value; \
} while (0)

#endif /* !_BITSTRING_H_ */
Commit	Line	Data
5b2abdfb A	1	/*
	2	* Copyright (c) 1989, 1993
	3	* The Regents of the University of California. All rights reserved.
	4	*
	5	* This code is derived from software contributed to Berkeley by
	6	* Paul Vixie.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* 2. Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in the
	15	* documentation and/or other materials provided with the distribution.
	16	* 3. All advertising materials mentioning features or use of this software
	17	* must display the following acknowledgement:
	18	* This product includes software developed by the University of
	19	* California, Berkeley and its contributors.
	20	* 4. Neither the name of the University nor the names of its contributors
	21	* may be used to endorse or promote products derived from this software
	22	* without specific prior written permission.
	23	*
	24	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	25	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	26	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	27	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	28	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	29	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	30	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	31	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	32	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	33	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	34	* SUCH DAMAGE.
	35	*
23e20b00	36	* $FreeBSD$
5b2abdfb A	37	*/
	38
	39	#ifndef _BITSTRING_H_
	40	#define _BITSTRING_H_
	41
	42	typedef unsigned char bitstr_t;
	43
	44	/* internal macros */
	45	/* byte of the bitstring bit is in */
	46	#define _bit_byte(bit) \
	47	((bit) >> 3)
	48
	49	/* mask for the bit within its byte */
	50	#define _bit_mask(bit) \
	51	(1 << ((bit)&0x7))
	52
	53	/* external macros */
	54	/* bytes in a bitstring of nbits bits */
	55	#define bitstr_size(nbits) \
23e20b00	56	(((nbits) + 7) >> 3)
5b2abdfb A	57
	58	/* allocate a bitstring */
	59	#define bit_alloc(nbits) \
23e20b00	60	(bitstr_t *)calloc((size_t)bitstr_size(nbits), sizeof(bitstr_t))
5b2abdfb A	61
	62	/* allocate a bitstring on the stack */
	63	#define bit_decl(name, nbits) \
23e20b00	64	((name)[bitstr_size(nbits)])
5b2abdfb A	65
	66	/* is bit N of bitstring name set? */
	67	#define bit_test(name, bit) \
	68	((name)[_bit_byte(bit)] & _bit_mask(bit))
	69
	70	/* set bit N of bitstring name */
	71	#define bit_set(name, bit) \
23e20b00	72	((name)[_bit_byte(bit)] \|= _bit_mask(bit))
5b2abdfb A	73
	74	/* clear bit N of bitstring name */
	75	#define bit_clear(name, bit) \
23e20b00	76	((name)[_bit_byte(bit)] &= ~_bit_mask(bit))
5b2abdfb A	77
5b2abdfb A	78	/* clear bits start ... stop in bitstring */
23e20b00 A	79	#define bit_nclear(name, start, stop) do { \
	80	bitstr_t *_name = (name); \
	81	int _start = (start), _stop = (stop); \
	82	int _startbyte = _bit_byte(_start); \
	83	int _stopbyte = _bit_byte(_stop); \
5b2abdfb A	84	if (_startbyte == _stopbyte) { \
	85	_name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) \| \
	86	(0xff << ((_stop&0x7) + 1))); \
	87	} else { \
	88	_name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \
	89	while (++_startbyte < _stopbyte) \
	90	_name[_startbyte] = 0; \
	91	_name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \
	92	} \
23e20b00	93	} while (0)
5b2abdfb A	94
5b2abdfb A	95	/* set bits start ... stop in bitstring */
23e20b00 A	96	#define bit_nset(name, start, stop) do { \
	97	bitstr_t *_name = (name); \
	98	int _start = (start), _stop = (stop); \
	99	int _startbyte = _bit_byte(_start); \
	100	int _stopbyte = _bit_byte(_stop); \
5b2abdfb A	101	if (_startbyte == _stopbyte) { \
	102	_name[_startbyte] \|= ((0xff << (_start&0x7)) & \
	103	(0xff >> (7 - (_stop&0x7)))); \
	104	} else { \
	105	_name[_startbyte] \|= 0xff << ((_start)&0x7); \
	106	while (++_startbyte < _stopbyte) \
	107	_name[_startbyte] = 0xff; \
	108	_name[_stopbyte] \|= 0xff >> (7 - (_stop&0x7)); \
	109	} \
23e20b00	110	} while (0)
5b2abdfb A	111
5b2abdfb A	112	/* find first bit clear in name */
23e20b00 A	113	#define bit_ffc(name, nbits, value) do { \
	114	bitstr_t *_name = (name); \
	115	int _byte, _nbits = (nbits); \
	116	int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \
	117	if (_nbits > 0) \
	118	for (_byte = 0; _byte <= _stopbyte; ++_byte) \
	119	if (_name[_byte] != 0xff) { \
	120	bitstr_t _lb; \
	121	_value = _byte << 3; \
	122	for (_lb = _name[_byte]; (_lb&0x1); \
	123	++_value, _lb >>= 1); \
	124	break; \
	125	} \
	126	if (_value >= nbits) \
	127	_value = -1; \
5b2abdfb	128	*(value) = _value; \
23e20b00	129	} while (0)
5b2abdfb A	130
5b2abdfb A	131	/* find first bit set in name */
23e20b00 A	132	#define bit_ffs(name, nbits, value) do { \
	133	bitstr_t *_name = (name); \
	134	int _byte, _nbits = (nbits); \
	135	int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \
	136	if (_nbits > 0) \
	137	for (_byte = 0; _byte <= _stopbyte; ++_byte) \
	138	if (_name[_byte]) { \
	139	bitstr_t _lb; \
	140	_value = _byte << 3; \
	141	for (_lb = _name[_byte]; !(_lb&0x1); \
	142	++_value, _lb >>= 1); \
	143	break; \
	144	} \
	145	if (_value >= nbits) \
	146	_value = -1; \
5b2abdfb	147	*(value) = _value; \
23e20b00	148	} while (0)
5b2abdfb A	149
5b2abdfb A	150	#endif /* !_BITSTRING_H_ */