usr/src/lib/libc/port/gen/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 (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 /*
  33  * convert long int to base 64 ascii
  34  * char set is [./0-9A-Za-z]
  35  * two's complement negatives are assumed,
  36  * but no assumptions are made about sign propagation on right shift
  37  *
  38  */
  39
  40 #include "lint.h"
  41 #include "mtlib.h"
  42 #include "libc.h"
  43 #include <values.h>
  44 #include <synch.h>
  45 #include <thread.h>
  46 #include <stdlib.h>
  47 #include <sys/types.h>
  48 #include "tsd.h"
  49
  50 #define BITSPERCHAR     6 /* to hold entire character set */
  51 #define BITSUSED        (BITSPERBYTE * sizeof (int))
  52 #define NMAX            ((BITSUSED + BITSPERCHAR - 1)/BITSPERCHAR)
  53 #define SIGN            (-(1 << (BITSUSED - BITSPERCHAR - 1)))
  54 #define CHARMASK        ((1 << BITSPERCHAR) - 1)
  55 #define WORDMASK        ((1 << ((NMAX - 1) * BITSPERCHAR)) - 1)
  56
  57 char *
  58 l64a(long value)
  59 {
  60         /* XPG4: only the lower 32 bits are used */
  61         int lg = (int)value;
  62         char *buf = tsdalloc(_T_L64A, NMAX + 1, NULL);
  63         char *s = buf;
  64
  65         if (buf == NULL)
  66                 return (NULL);
  67
  68         while (lg != 0) {
  69
  70                 int c = (lg & CHARMASK) + ('0' - 2);
  71
  72                 if (c > '9')
  73                         c += 'A' - '9' - 1;
  74                 if (c > 'Z')
  75                         c += 'a' - 'Z' - 1;
  76                 *s++ = (char)c;
  77                 /* fill high-order CHAR if negative */
  78                 /* but suppress sign propagation */
  79                 lg = ((lg < 0) ? (lg >> BITSPERCHAR) | SIGN :
  80                     lg >> BITSPERCHAR) & WORDMASK;
  81         }
  82         *s = '\0';
  83         return (buf);
  84 }