xref: /titanic_50/usr/src/lib/libbc/libc/gen/common/l64a.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*      Copyright (c) 1984 AT&T */
/*        All Rights Reserved   */

#pragma ident	"%Z%%M%	%I%	%E% SMI"  /* from S5R2 1.5 */

/*LINTLIBRARY*/
/*
 * convert long int to base 64 ascii
 * char set is [./0-9A-Za-z]
 * two's complement negatives are assumed,
 * but no assumptions are made about sign propagation on right shift
 *
 */

#include <values.h>
#define BITSPERCHAR	6 /* to hold entire character set */
#define BITSPERLONG	(BITSPERBYTE * sizeof(long))
#define NMAX	((BITSPERLONG + BITSPERCHAR - 1)/BITSPERCHAR)
#define SIGN	(-(1L << (BITSPERLONG - BITSPERCHAR - 1)))
#define CHARMASK	((1 << BITSPERCHAR) - 1)
#define WORDMASK	((1L << ((NMAX - 1) * BITSPERCHAR)) - 1)

static char buf[NMAX + 1];

char *
l64a(lg)
register long lg;
{
	register char *s = buf;

	while (lg != 0) {

		register int c = ((int)lg & CHARMASK) + ('0' - 2);

		if (c > '9')
			c += 'A' - '9' - 1;
		if (c > 'Z')
			c += 'a' - 'Z' - 1;
		*s++ = c;
		/* fill high-order CHAR if negative */
		/* but suppress sign propagation */
		lg = ((lg < 0) ? (lg >> BITSPERCHAR) | SIGN :
			lg >> BITSPERCHAR) & WORDMASK;
	}
	*s = '\0';
	return (buf);
}