libs/libgdtoa/g_xLfmt.c

   1 /****************************************************************
   2
   3 The author of this software is David M. Gay.
   4
   5 Copyright (C) 1998 by Lucent Technologies
   6 All Rights Reserved
   7
   8 Permission to use, copy, modify, and distribute this software and
   9 its documentation for any purpose and without fee is hereby
  10 granted, provided that the above copyright notice appear in all
  11 copies and that both that the copyright notice and this
  12 permission notice and warranty disclaimer appear in supporting
  13 documentation, and that the name of Lucent or any of its entities
  14 not be used in advertising or publicity pertaining to
  15 distribution of the software without specific, written prior
  16 permission.
  17
  18 LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  19 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
  20 IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
  21 SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  22 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
  23 IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
  24 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
  25 THIS SOFTWARE.
  26
  27 ****************************************************************/
  28
  29 /* Please send bug reports to David M. Gay (dmg at acm dot org,
  30  * with " at " changed at "@" and " dot " changed to ".").      */
  31
  32 #include "gdtoaimp.h"
  33
  34 #undef _0
  35 #undef _1
  36
  37 /* one or the other of IEEE_MC68k or IEEE_8087 should be #defined */
  38
  39 #ifdef IEEE_MC68k
  40 #define _0 0
  41 #define _1 1
  42 #define _2 2
  43 #endif
  44 #ifdef IEEE_8087
  45 #define _0 2
  46 #define _1 1
  47 #define _2 0
  48 #endif
  49
  50  char*
  51 #ifdef KR_headers
  52 g_xLfmt(buf, V, ndig, bufsize) char *buf; char *V; int ndig; unsigned bufsize;
  53 #else
  54 g_xLfmt(char *buf, void *V, int ndig, unsigned bufsize)
  55 #endif
  56 {
  57         static FPI fpi = { 64, 1-16383-64+1, 32766 - 16383 - 64 + 1, 1, 0 };
  58         char *b, *s, *se;
  59         ULong bits[2], *L, sign;
  60         int decpt, ex, i, mode;
  61
  62         if (ndig < 0)
  63                 ndig = 0;
  64         if (bufsize < ndig + 10)
  65                 return 0;
  66
  67         L = (ULong*)V;
  68         sign = L[_0] & 0x80000000L;
  69         bits[1] = L[_1];
  70         bits[0] = L[_2];
  71         if ( (ex = (L[_0] >> 16) & 0x7fff) !=0) {
  72                 if (ex == 0x7fff) {
  73                         /* Infinity or NaN */
  74                         if (bits[0] | bits[1])
  75                                 b = strcp(buf, "NaN");
  76                         else {
  77                                 b = buf;
  78                                 if (sign)
  79                                         *b++ = '-';
  80                                 b = strcp(b, "Infinity");
  81                                 }
  82                         return b;
  83                         }
  84                 i = STRTOG_Normal;
  85                 }
  86         else if (bits[0] | bits[1]) {
  87                 i = STRTOG_Denormal;
  88                 }
  89         else {
  90                 b = buf;
  91 #ifndef IGNORE_ZERO_SIGN
  92                 if (sign)
  93                         *b++ = '-';
  94 #endif
  95                 *b++ = '0';
  96                 *b = 0;
  97                 return b;
  98                 }
  99         ex -= 0x3fff + 63;
 100         mode = 2;
 101         if (ndig <= 0) {
 102                 if (bufsize < 32)
 103                         return 0;
 104                 mode = 0;
 105                 }
 106         s = gdtoa(&fpi, ex, bits, &i, mode, ndig, &decpt, &se);
 107         return g__fmt(buf, s, se, decpt, sign);
 108         }