xref: /titanic_50/usr/src/lib/libbc/libc/gen/common/l64a.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*      Copyright (c) 1984 AT&T */
23 /*        All Rights Reserved   */
24 
25 #pragma ident	"%Z%%M%	%I%	%E% SMI"  /* from S5R2 1.5 */
26 
27 /*LINTLIBRARY*/
28 /*
29  * convert long int to base 64 ascii
30  * char set is [./0-9A-Za-z]
31  * two's complement negatives are assumed,
32  * but no assumptions are made about sign propagation on right shift
33  *
34  */
35 
36 #include <values.h>
37 #define BITSPERCHAR	6 /* to hold entire character set */
38 #define BITSPERLONG	(BITSPERBYTE * sizeof(long))
39 #define NMAX	((BITSPERLONG + BITSPERCHAR - 1)/BITSPERCHAR)
40 #define SIGN	(-(1L << (BITSPERLONG - BITSPERCHAR - 1)))
41 #define CHARMASK	((1 << BITSPERCHAR) - 1)
42 #define WORDMASK	((1L << ((NMAX - 1) * BITSPERCHAR)) - 1)
43 
44 static char buf[NMAX + 1];
45 
46 char *
l64a(lg)47 l64a(lg)
48 register long lg;
49 {
50 	register char *s = buf;
51 
52 	while (lg != 0) {
53 
54 		register int c = ((int)lg & CHARMASK) + ('0' - 2);
55 
56 		if (c > '9')
57 			c += 'A' - '9' - 1;
58 		if (c > 'Z')
59 			c += 'a' - 'Z' - 1;
60 		*s++ = c;
61 		/* fill high-order CHAR if negative */
62 		/* but suppress sign propagation */
63 		lg = ((lg < 0) ? (lg >> BITSPERCHAR) | SIGN :
64 			lg >> BITSPERCHAR) & WORDMASK;
65 	}
66 	*s = '\0';
67 	return (buf);
68 }
69