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 30 David M. Gay 31 dmg@acm.org 32 */ 33 34 #include "gdtoaimp.h" 35 36 #ifdef USE_LOCALE 37 #include "locale.h" 38 #endif 39 40 int 41 #ifdef KR_headers 42 gethex(sp, fpi, exp, bp, sign) 43 CONST char **sp; FPI *fpi; Long *exp; Bigint **bp; int sign; 44 #else 45 gethex( CONST char **sp, FPI *fpi, Long *exp, Bigint **bp, int sign) 46 #endif 47 { 48 Bigint *b; 49 CONST unsigned char *decpt, *s0, *s, *s1; 50 int esign, havedig, irv, k, n, nbits, up; 51 ULong L, lostbits, *x; 52 Long e, e1; 53 #ifdef USE_LOCALE 54 char decimalpoint = *localeconv()->decimal_point; 55 #else 56 #define decimalpoint '.' 57 #endif 58 59 if (!hexdig['0']) 60 hexdig_init_D2A(); 61 havedig = 0; 62 s0 = *(CONST unsigned char **)sp + 2; 63 while(s0[havedig] == '0') 64 havedig++; 65 s0 += havedig; 66 s = s0; 67 decpt = 0; 68 if (!hexdig[*s]) { 69 if (*s == decimalpoint) { 70 decpt = ++s; 71 if (!hexdig[*s]) 72 goto ret0; 73 } 74 else { 75 ret0: 76 *sp = (char*)s; 77 return havedig ? STRTOG_Zero : STRTOG_NoNumber; 78 } 79 while(*s == '0') 80 s++; 81 havedig = 1; 82 if (!hexdig[*s]) 83 goto ret0; 84 s0 = s; 85 } 86 while(hexdig[*s]) 87 s++; 88 if (*s == decimalpoint && !decpt) { 89 decpt = ++s; 90 while(hexdig[*s]) 91 s++; 92 } 93 e = 0; 94 if (decpt) 95 e = -(((Long)(s-decpt)) << 2); 96 s1 = s; 97 switch(*s) { 98 case 'p': 99 case 'P': 100 esign = 0; 101 switch(*++s) { 102 case '-': 103 esign = 1; 104 /* no break */ 105 case '+': 106 s++; 107 } 108 if ((n = hexdig[*s]) == 0 || n > 0x19) { 109 s = s1; 110 break; 111 } 112 e1 = n - 0x10; 113 while((n = hexdig[*++s]) !=0 && n <= 0x19) 114 e1 = 10*e1 + n - 0x10; 115 if (esign) 116 e1 = -e1; 117 e += e1; 118 } 119 *sp = (char*)s; 120 n = s1 - s0 - 1; 121 for(k = 0; n > 7; n >>= 1) 122 k++; 123 b = Balloc(k); 124 x = b->x; 125 n = 0; 126 L = 0; 127 while(s1 > s0) { 128 if (*--s1 == decimalpoint) 129 continue; 130 if (n == 32) { 131 *x++ = L; 132 L = 0; 133 n = 0; 134 } 135 L |= (hexdig[*s1] & 0x0f) << n; 136 n += 4; 137 } 138 *x++ = L; 139 b->wds = n = x - b->x; 140 n = 32*n - hi0bits(L); 141 nbits = fpi->nbits; 142 lostbits = 0; 143 x = b->x; 144 if (n > nbits) { 145 n -= nbits; 146 if (any_on(b,n)) { 147 lostbits = 1; 148 k = n - 1; 149 if (x[k>>kshift] & 1 << (k & kmask)) { 150 lostbits = 2; 151 if (k > 1 && any_on(b,k-1)) 152 lostbits = 3; 153 } 154 } 155 rshift(b, n); 156 e += n; 157 } 158 else if (n < nbits) { 159 n = nbits - n; 160 b = lshift(b, n); 161 e -= n; 162 x = b->x; 163 } 164 if (e > fpi->emax) { 165 ovfl: 166 Bfree(b); 167 return STRTOG_Infinite | STRTOG_Overflow | STRTOG_Inexhi; 168 } 169 irv = STRTOG_Normal; 170 if (e < fpi->emin) { 171 irv = STRTOG_Denormal; 172 n = fpi->emin - e; 173 if (n >= nbits) { 174 switch (fpi->rounding) { 175 case FPI_Round_near: 176 if (n == nbits && n < 2 || any_on(b,n-1)) 177 goto one_bit; 178 break; 179 case FPI_Round_up: 180 if (!sign) 181 goto one_bit; 182 break; 183 case FPI_Round_down: 184 if (sign) { 185 one_bit: 186 *exp = fpi->emin; 187 x[0] = b->wds = 1; 188 *bp = b; 189 return STRTOG_Denormal | STRTOG_Inexhi 190 | STRTOG_Underflow; 191 } 192 } 193 Bfree(b); 194 return STRTOG_Zero | STRTOG_Inexlo | STRTOG_Underflow; 195 } 196 k = n - 1; 197 if (lostbits) 198 lostbits = 1; 199 else if (k > 0) 200 lostbits = any_on(b,k); 201 if (x[k>>kshift] & 1 << (k & kmask)) 202 lostbits |= 2; 203 nbits -= n; 204 rshift(b,n); 205 e = fpi->emin; 206 } 207 if (lostbits) { 208 up = 0; 209 switch(fpi->rounding) { 210 case FPI_Round_zero: 211 break; 212 case FPI_Round_near: 213 if (lostbits & 2 214 && (lostbits & 1) | x[0] & 1) 215 up = 1; 216 break; 217 case FPI_Round_up: 218 up = 1 - sign; 219 break; 220 case FPI_Round_down: 221 up = sign; 222 } 223 if (up) { 224 k = b->wds; 225 b = increment(b); 226 x = b->x; 227 if (b->wds > k 228 || (n = nbits & kmask) !=0 229 && hi0bits(x[k-1]) < 32-n) { 230 rshift(b,1); 231 if (++e > fpi->emax) 232 goto ovfl; 233 } 234 else if (irv == STRTOG_Denormal) { 235 k = nbits - 1; 236 if (x[k >> kshift] & 1 << (k & kmask)) 237 irv = STRTOG_Normal; 238 } 239 irv |= STRTOG_Inexhi; 240 } 241 else 242 irv |= STRTOG_Inexlo; 243 } 244 *bp = b; 245 *exp = e; 246 return irv; 247 } 248