xref: /f-stack/tools/compat/include/sys/_bitset.h (revision 8cf1d457)
1 /*-
2  * Copyright (c) 2008, Jeffrey Roberson <[email protected]>
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) * 8)
40 
41 #define	__howmany(x, y)	(((x) + ((y) - 1)) / (y))
42 
43 #define	__bitset_words(_s)	(__howmany(_s, _BITSET_BITS))
44 
45 #define	BITSET_DEFINE(t, _s)						\
46 struct t {								\
47         long    __bits[__bitset_words((_s))];				\
48 }
49 
50 /*
51  * Helper to declare a bitset without it's size being a constant.
52  *
53  * Sadly we cannot declare a bitset struct with '__bits[]', because it's
54  * the only member of the struct and the compiler complains.
55  */
56 #define BITSET_DEFINE_VAR(t)	BITSET_DEFINE(t, 1)
57 
58 #endif /* !_SYS__BITSET_H_ */
59