xref: /illumos-gate/usr/src/cmd/sendmail/include/sm/bitops.h (revision 2a8bcb4efb45d99ac41c94a75c396b362c414f7f)
1 /*
2  * Copyright (c) 1998-2001 Sendmail, Inc. and its suppliers.
3  *	All rights reserved.
4  * Copyright (c) 1983, 1995-1997 Eric P. Allman.  All rights reserved.
5  * Copyright (c) 1988, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * By using this file, you agree to the terms and conditions set
9  * forth in the LICENSE file which can be found at the top level of
10  * the sendmail distribution.
11  *
12  *
13  *	$Id: bitops.h,v 1.2 2001/09/22 22:05:42 ca Exp $
14  */
15 
16 #ifndef	SM_BITOPS_H
17 # define SM_BITOPS_H
18 
19 /*
20 **  Data structure for bit maps.
21 **
22 **	Each bit in this map can be referenced by an ascii character.
23 **	This is 256 possible bits, or 32 8-bit bytes.
24 */
25 
26 # define BITMAPBITS	256	/* number of bits in a bit map */
27 # define BYTEBITS	8	/* number of bits in a byte */
28 # define BITMAPBYTES	(BITMAPBITS / BYTEBITS)	/* number of bytes in bit map */
29 # define BITMAPMAX	((BITMAPBYTES / sizeof (int)) - 1)
30 
31 /* internal macros */
32 
33 /* make sure this index never leaves the allowed range: 0 to BITMAPMAX */
34 # define _BITWORD(bit)	(((unsigned char)(bit) / (BYTEBITS * sizeof (int))) & BITMAPMAX)
35 # define _BITBIT(bit)	((unsigned int)1 << ((unsigned char)(bit) % (BYTEBITS * sizeof (int))))
36 
37 typedef unsigned int	BITMAP256[BITMAPBYTES / sizeof (int)];
38 
39 /* properly case and truncate bit */
40 # define bitidx(bit)		((unsigned int) (bit) & 0xff)
41 
42 /* test bit number N */
43 # define bitnset(bit, map)	((map)[_BITWORD(bit)] & _BITBIT(bit))
44 
45 /* set bit number N */
46 # define setbitn(bit, map)	(map)[_BITWORD(bit)] |= _BITBIT(bit)
47 
48 /* clear bit number N */
49 # define clrbitn(bit, map)	(map)[_BITWORD(bit)] &= ~_BITBIT(bit)
50 
51 /* clear an entire bit map */
52 # define clrbitmap(map)		memset((char *) map, '\0', BITMAPBYTES)
53 
54 /* bit hacking */
55 # define bitset(bit, word)	(((word) & (bit)) != 0)
56 
57 #endif /* ! SM_BITOPS_H */
58