gdtoa/FreeBSD/gdtoa-strtof.c

   1 /****************************************************************
   2
   3 The author of this software is David M. Gay.
   4
   5 Copyright (C) 1998, 2000 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  float
  35 #ifdef KR_headers
  36 strtof(s, sp) CONST char *s; char **sp;
  37 #else
  38 strtof(CONST char *s, char **sp)
  39 #endif
  40 {
  41         static FPI fpi0 = { 24, 1-127-24+1,  254-127-24+1, 1, SI };
  42         ULong bits[1];
  43         Long exp;
  44         int k;
  45         union { ULong L[1]; float f; } u;
  46 #ifdef Honor_FLT_ROUNDS
  47 #include "gdtoa_fltrnds.h"
  48 #else
  49 #define fpi &fpi0
  50 #endif
  51
  52         k = strtodg(s, sp, fpi, &exp, bits);
  53         switch(k & STRTOG_Retmask) {
  54           case STRTOG_NoNumber:
  55           case STRTOG_Zero:
  56                 u.L[0] = 0;
  57                 break;
  58
  59           case STRTOG_Normal:
  60           case STRTOG_NaNbits:
  61                 u.L[0] = (bits[0] & 0x7fffff) | ((exp + 0x7f + 23) << 23);
  62                 break;
  63
  64           case STRTOG_Denormal:
  65                 u.L[0] = bits[0];
  66                 break;
  67
  68           case STRTOG_Infinite:
  69                 u.L[0] = 0x7f800000;
  70                 break;
  71
  72           case STRTOG_NaN:
  73                 u.L[0] = f_QNAN;
  74           }
  75         if (k & STRTOG_Neg)
  76                 u.L[0] |= 0x80000000L;
  77         return u.f;
  78         }