contrib/gdtoa/hexnan.c

   1 /****************************************************************
   2
   3 The author of this software is David M. Gay.
   4
   5 Copyright (C) 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 /* $FreeBSD$ */
  33
  34 #include "gdtoaimp.h"
  35
  36  static void
  37 #ifdef KR_headers
  38 L_shift(x, x1, i) ULong *x; ULong *x1; int i;
  39 #else
  40 L_shift(ULong *x, ULong *x1, int i)
  41 #endif
  42 {
  43         int j;
  44
  45         i = 8 - i;
  46         i <<= 2;
  47         j = ULbits - i;
  48         do {
  49                 *x |= x[1] << j;
  50                 x[1] >>= i;
  51                 } while(++x < x1);
  52         }
  53
  54  int
  55 #ifdef KR_headers
  56 hexnan(sp, fpi, x0)
  57         CONST char **sp; FPI *fpi; ULong *x0;
  58 #else
  59 hexnan( CONST char **sp, FPI *fpi, ULong *x0)
  60 #endif
  61 {
  62         ULong c, h, *x, *x1, *xe;
  63         CONST char *s;
  64         int havedig, hd0, i, nbits;
  65
  66         if (!hexdig['0'])
  67                 hexdig_init_D2A();
  68         nbits = fpi->nbits;
  69         x = x0 + (nbits >> kshift);
  70         if (nbits & kmask)
  71                 x++;
  72         *--x = 0;
  73         x1 = xe = x;
  74         havedig = hd0 = i = 0;
  75         s = *sp;
  76
  77         /* FreeBSD local: Accept (but ignore) the '0x' prefix. */
  78         if (s[1] == '0' && (s[2] == 'x' || s[2] == 'X'))
  79                 s += 2;
  80
  81         while(c = *(CONST unsigned char*)++s) {
  82                 if (!(h = hexdig[c])) {
  83 #if 0
  84                         if (c <= ' ') {
  85                                 if (hd0 < havedig) {
  86                                         if (x < x1 && i < 8)
  87                                                 L_shift(x, x1, i);
  88                                         if (x <= x0) {
  89                                                 i = 8;
  90                                                 continue;
  91                                                 }
  92                                         hd0 = havedig;
  93                                         *--x = 0;
  94                                         x1 = x;
  95                                         i = 0;
  96                                         }
  97                                 continue;
  98                                 }
  99                         if (/*(*/ c == ')' && havedig) {
 100                                 *sp = s + 1;
 101                                 break;
 102                                 }
 103 #endif
 104                         break;
 105                         }
 106                 havedig++;
 107                 if (++i > 8) {
 108                         if (x <= x0)
 109                                 continue;
 110                         i = 1;
 111                         *--x = 0;
 112                         }
 113                 *x = (*x << 4) | h & 0xf;
 114                 }
 115         if (havedig && x < x1 && i < 8)
 116                 L_shift(x, x1, i);
 117         if (x > x0) {
 118                 x1 = x0;
 119                 do *x1++ = *x++;
 120                         while(x <= xe);
 121                 do *x1++ = 0;
 122                         while(x1 <= xe);
 123                 }
 124         else {
 125                 /* truncate high-order word if necessary */
 126                 if ( (i = nbits & (ULbits-1)) !=0)
 127                         *xe &= ((ULong)0xffffffff) >> (ULbits - i);
 128                 }
 129         if (havedig) {
 130         for(x1 = xe;; --x1) {
 131                 if (*x1 != 0)
 132                         break;
 133                 if (x1 == x0) {
 134                         *x1 = 1;
 135                         break;
 136                         }
 137                 }
 138         }
 139
 140         /*
 141          * FreeBSD local: Accept all the sequences allowed by C99 and update
 142          * the tail pointer correctly. Don't accept any invalid sequences.
 143          */
 144         if (c == '\0')  /* nan() calls this, too; tolerate a missing ')' */
 145                 return STRTOG_NaNbits;
 146         if (c != ')') {
 147                 while(c = *(CONST unsigned char*)++s) {
 148                         if (c == ')')
 149                                 break;
 150                         if (!isalnum(c) && c != '_')
 151                                 return STRTOG_NaNbits;
 152                 }
 153         }
 154         *sp = s + 1;
 155         return STRTOG_NaNbits;
 156         }