xref: /freebsd/sys/sys/_bitset.h (revision f05cddf9)
1 /*-
2  * Copyright (c) 2008, Jeffrey Roberson <jeff@freebsd.org>
3  * All rights reserved.
4  *
5  * Copyright (c) 2008 Nokia Corporation
6  * All rights reserved.
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 unmodified, this list of conditions, and the following
13  *    disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 #ifndef _SYS__BITSET_H_
33 #define	_SYS__BITSET_H_
34 
35 /*
36  * Macros addressing word and bit within it, tuned to make compiler
37  * optimize cases when SETSIZE fits into single machine word.
38  */
39 #define	_BITSET_BITS		(sizeof(long) * NBBY)
40 
41 #define	__bitset_words(_s)	(howmany(_s, _BITSET_BITS))
42 
43 #define	__bitset_mask(_s, n)						\
44 	(1L << ((__bitset_words((_s)) == 1) ?				\
45 	    (__size_t)(n) : ((n) % _BITSET_BITS)))
46 
47 #define	__bitset_word(_s, n)						\
48 	((__bitset_words((_s)) == 1) ? 0 : ((n) / _BITSET_BITS))
49 
50 #define	BITSET_DEFINE(t, _s)						\
51 struct t {								\
52         long    __bits[__bitset_words((_s))];				\
53 };
54 
55 #define	BITSET_T_INITIALIZER(x)						\
56 	{ .__bits = { x } }
57 
58 #define	BITSET_FSET(n)							\
59 	[ 0 ... ((n) - 1) ] = (-1L)
60 
61 #endif /* !_SYS__BITSET_H_ */
62