[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.
 *
 *	@(#)bitstring.h	8.1 (Berkeley) 7/19/93
 */

#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) - 1) >> 3) + 1)

				/* allocate a bitstring */
#define	bit_alloc(nbits) \
	(bitstr_t *)calloc(1, \
	    (unsigned int)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) { \
	register bitstr_t *_name = name; \
	register int _start = start, _stop = stop; \
	register int _startbyte = _bit_byte(_start); \
	register 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); \
	} \
}

				/* set bits start ... stop in bitstring */
#define	bit_nset(name, start, stop) { \
	register bitstr_t *_name = name; \
	register int _start = start, _stop = stop; \
	register int _startbyte = _bit_byte(_start); \
	register 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)); \
	} \
}

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

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

#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	*
	36	* @(#)bitstring.h 8.1 (Berkeley) 7/19/93
	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) \
	56	((((nbits) - 1) >> 3) + 1)
	57
	58	/* allocate a bitstring */
	59	#define bit_alloc(nbits) \
	60	(bitstr_t *)calloc(1, \
	61	(unsigned int)bitstr_size(nbits) * sizeof(bitstr_t))
	62
	63	/* allocate a bitstring on the stack */
	64	#define bit_decl(name, nbits) \
65	(name)[bitstr_size(nbits)]
66
67	/* is bit N of bitstring name set? */
68	#define bit_test(name, bit) \
69	((name)[_bit_byte(bit)] & _bit_mask(bit))
70
71	/* set bit N of bitstring name */
72	#define bit_set(name, bit) \
73	(name)[_bit_byte(bit)] \|= _bit_mask(bit)
74
75	/* clear bit N of bitstring name */
76	#define bit_clear(name, bit) \
77	(name)[_bit_byte(bit)] &= ~_bit_mask(bit)
78
79	/* clear bits start ... stop in bitstring */
80	#define bit_nclear(name, start, stop) { \
81	register bitstr_t *_name = name; \
82	register int _start = start, _stop = stop; \
83	register int _startbyte = _bit_byte(_start); \
84	register int _stopbyte = _bit_byte(_stop); \
85	if (_startbyte == _stopbyte) { \
86	_name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) \| \
87	(0xff << ((_stop&0x7) + 1))); \
88	} else { \
89	_name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \
90	while (++_startbyte < _stopbyte) \
91	_name[_startbyte] = 0; \
92	_name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \
93	} \
94	}
95
96	/* set bits start ... stop in bitstring */
97	#define bit_nset(name, start, stop) { \
98	register bitstr_t *_name = name; \
99	register int _start = start, _stop = stop; \
100	register int _startbyte = _bit_byte(_start); \
101	register int _stopbyte = _bit_byte(_stop); \
102	if (_startbyte == _stopbyte) { \
103	_name[_startbyte] \|= ((0xff << (_start&0x7)) & \
104	(0xff >> (7 - (_stop&0x7)))); \
105	} else { \
106	_name[_startbyte] \|= 0xff << ((_start)&0x7); \
107	while (++_startbyte < _stopbyte) \
108	_name[_startbyte] = 0xff; \
109	_name[_stopbyte] \|= 0xff >> (7 - (_stop&0x7)); \
110	} \
111	}
112
113	/* find first bit clear in name */
114	#define bit_ffc(name, nbits, value) { \
115	register bitstr_t *_name = name; \
116	register int _byte, _nbits = nbits; \
117	register int _stopbyte = _bit_byte(_nbits), _value = -1; \
118	for (_byte = 0; _byte < _stopbyte; ++_byte) \
119	if (_name[_byte] != 0xff) { \
120	_value = _byte << 3; \
121	for (_stopbyte = _name[_byte]; (_stopbyte&0x1); \
122	++_value, _stopbyte >>= 1); \
123	break; \
124	} \
125	*(value) = _value; \
126	}
127
128	/* find first bit set in name */
129	#define bit_ffs(name, nbits, value) { \
130	register bitstr_t *_name = name; \
131	register int _byte, _nbits = nbits; \
132	register int _stopbyte = _bit_byte(_nbits), _value = -1; \
133	for (_byte = 0; _byte < _stopbyte; ++_byte) \
134	if (_name[_byte]) { \
135	_value = _byte << 3; \
136	for (_stopbyte = _name[_byte]; !(_stopbyte&0x1); \
137	++_value, _stopbyte >>= 1); \
138	break; \
139	} \
140	*(value) = _value; \
141	}
142
143	#endif /* !_BITSTRING_H_ */