contrib/gdtoa/strtorx.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 #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 #define _3 3
  44 #define _4 4
  45 #endif
  46 #ifdef IEEE_8087
  47 #define _0 4
  48 #define _1 3
  49 #define _2 2
  50 #define _3 1
  51 #define _4 0
  52 #endif
  53
  54  void
  55 #ifdef KR_headers
  56 ULtox(L, bits, exp, k) UShort *L; ULong *bits; Long exp; int k;
  57 #else
  58 ULtox(UShort *L, ULong *bits, Long exp, int k)
  59 #endif
  60 {
  61         switch(k & STRTOG_Retmask) {
  62           case STRTOG_NoNumber:
  63           case STRTOG_Zero:
  64                 L[0] = L[1] = L[2] = L[3] = L[4] = 0;
  65                 break;
  66
  67           case STRTOG_Denormal:
  68                 L[_0] = 0;
  69                 goto normal_bits;
  70
  71           case STRTOG_Normal:
  72           case STRTOG_NaNbits:
  73                 L[_0] = exp + 0x3fff + 63;
  74  normal_bits:
  75                 L[_4] = (UShort)bits[0];
  76                 L[_3] = (UShort)(bits[0] >> 16);
  77                 L[_2] = (UShort)bits[1];
  78                 L[_1] = (UShort)(bits[1] >> 16);
  79                 break;
  80
  81           case STRTOG_Infinite:
  82                 L[_0] = 0x7fff;
  83                 L[_1] = L[_2] = L[_3] = L[_4] = 0;
  84                 break;
  85
  86           case STRTOG_NaN:
  87                 L[0] = ldus_QNAN0;
  88                 L[1] = ldus_QNAN1;
  89                 L[2] = ldus_QNAN2;
  90                 L[3] = ldus_QNAN3;
  91                 L[4] = ldus_QNAN4;
  92           }
  93         if (k & STRTOG_Neg)
  94                 L[_0] |= 0x8000;
  95         }
  96
  97  int
  98 #ifdef KR_headers
  99 strtorx(s, sp, rounding, L) CONST char *s; char **sp; int rounding; void *L;
 100 #else
 101 strtorx(CONST char *s, char **sp, int rounding, void *L)
 102 #endif
 103 {
 104         static FPI fpi0 = { 64, 1-16383-64+1, 32766 - 16383 - 64 + 1, 1, SI };
 105         FPI *fpi, fpi1;
 106         ULong bits[2];
 107         Long exp;
 108         int k;
 109
 110         fpi = &fpi0;
 111         if (rounding != FPI_Round_near) {
 112                 fpi1 = fpi0;
 113                 fpi1.rounding = rounding;
 114                 fpi = &fpi1;
 115                 }
 116         k = strtodg(s, sp, fpi, &exp, bits);
 117         ULtox((UShort*)L, bits, exp, k);
 118         return k;
 119         }