usr/src/lib/libbc/libc/gen/common/l64a.c

   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 *
  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 }