lib/libc/gdtoa/g_xLfmt.c

   1 /* $NetBSD: g_xLfmt.c,v 1.3 2008/03/21 23:13:48 christos Exp $ */
   2
   3 /****************************************************************
   4
   5 The author of this software is David M. Gay.
   6
   7 Copyright (C) 1998 by Lucent Technologies
   8 All Rights Reserved
   9
  10 Permission to use, copy, modify, and distribute this software and
  11 its documentation for any purpose and without fee is hereby
  12 granted, provided that the above copyright notice appear in all
  13 copies and that both that the copyright notice and this
  14 permission notice and warranty disclaimer appear in supporting
  15 documentation, and that the name of Lucent or any of its entities
  16 not be used in advertising or publicity pertaining to
  17 distribution of the software without specific, written prior
  18 permission.
  19
  20 LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  21 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
  22 IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
  23 SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  24 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
  25 IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
  26 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
  27 THIS SOFTWARE.
  28
  29 ****************************************************************/
  30
  31 /* Please send bug reports to David M. Gay (dmg at acm dot org,
  32  * with " at " changed at "@" and " dot " changed to ".").      */
  33
  34 #include "gdtoaimp.h"
  35
  36 #undef _0
  37 #undef _1
  38
  39 /* one or the other of IEEE_BIG_ENDIAN or IEEE_LITTLE_ENDIAN should be #defined */
  40
  41 #ifdef IEEE_BIG_ENDIAN
  42 #define _0 0
  43 #define _1 1
  44 #define _2 2
  45 #endif
  46 #ifdef IEEE_LITTLE_ENDIAN
  47 #define _0 2
  48 #define _1 1
  49 #define _2 0
  50 #endif
  51
  52  char*
  53 #ifdef KR_headers
  54 g_xLfmt(buf, V, ndig, bufsize) char *buf; char *V; int ndig; unsigned bufsize;
  55 #else
  56 g_xLfmt(char *buf, void *V, int ndig, unsigned bufsize)
  57 #endif
  58 {
  59         static FPI fpi = { 64, 1-16383-64+1, 32766 - 16383 - 64 + 1, 1, 0 };
  60         char *b, *s, *se;
  61         ULong bits[2], *L, sign;
  62         int decpt, ex, i, mode;
  63
  64         if (ndig < 0)
  65                 ndig = 0;
  66         if (bufsize < ndig + 10)
  67                 return 0;
  68
  69         L = (ULong*)V;
  70         sign = L[_0] & 0x80000000L;
  71         bits[1] = L[_1];
  72         bits[0] = L[_2];
  73         if ( (ex = (L[_0] >> 16) & 0x7fff) !=0) {
  74                 if (ex == 0x7fff) {
  75                         /* Infinity or NaN */
  76                         if (bits[0] | bits[1])
  77                                 b = strcp(buf, "NaN");
  78                         else {
  79                                 b = buf;
  80                                 if (sign)
  81                                         *b++ = '-';
  82                                 b = strcp(b, "Infinity");
  83                                 }
  84                         return b;
  85                         }
  86                 i = STRTOG_Normal;
  87                 }
  88         else if (bits[0] | bits[1]) {
  89                 i = STRTOG_Denormal;
  90                 }
  91         else {
  92                 b = buf;
  93 #ifndef IGNORE_ZERO_SIGN
  94                 if (sign)
  95                         *b++ = '-';
  96 #endif
  97                 *b++ = '0';
  98                 *b = 0;
  99                 return b;
 100                 }
 101         ex -= 0x3fff + 63;
 102         mode = 2;
 103         if (ndig <= 0) {
 104                 if (bufsize < 32)
 105                         return 0;
 106                 mode = 0;
 107                 }
 108         s = gdtoa(&fpi, ex, bits, &i, mode, ndig, &decpt, &se);
 109         if (s == NULL)
 110                 return NULL;
 111         return g__fmt(buf, s, se, decpt, sign);
 112         }