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 static double 35 #ifdef KR_headers 36 ulpdown(d) U *d; 37 #else 38 ulpdown(U *d) 39 #endif 40 { 41 double u; 42 ULong *L = d->L; 43 44 u = ulp(d); 45 if (!(L[_1] | (L[_0] & 0xfffff)) 46 && (L[_0] & 0x7ff00000) > 0x00100000) 47 u *= 0.5; 48 return u; 49 } 50 51 int 52 #ifdef KR_headers 53 strtodI(s, sp, dd) CONST char *s; char **sp; double *dd; 54 #else 55 strtodI(CONST char *s, char **sp, double *dd) 56 #endif 57 { 58 static FPI fpi = { 53, 1-1023-53+1, 2046-1023-53+1, 1, SI }; 59 ULong bits[2], sign; 60 Long exp; 61 int j, k; 62 U *u; 63 64 k = strtodg(s, sp, &fpi, &exp, bits); 65 u = (U*)dd; 66 sign = k & STRTOG_Neg ? 0x80000000L : 0; 67 switch(k & STRTOG_Retmask) { 68 case STRTOG_NoNumber: 69 dval(&u[0]) = dval(&u[1]) = 0.; 70 break; 71 72 case STRTOG_Zero: 73 dval(&u[0]) = dval(&u[1]) = 0.; 74 #ifdef Sudden_Underflow 75 if (k & STRTOG_Inexact) { 76 if (sign) 77 word0(&u[0]) = 0x80100000L; 78 else 79 word0(&u[1]) = 0x100000L; 80 } 81 break; 82 #else 83 goto contain; 84 #endif 85 86 case STRTOG_Denormal: 87 word1(&u[0]) = bits[0]; 88 word0(&u[0]) = bits[1]; 89 goto contain; 90 91 case STRTOG_Normal: 92 word1(&u[0]) = bits[0]; 93 word0(&u[0]) = (bits[1] & ~0x100000) | ((exp + 0x3ff + 52) << 20); 94 contain: 95 j = k & STRTOG_Inexact; 96 if (sign) { 97 word0(&u[0]) |= sign; 98 j = STRTOG_Inexact - j; 99 } 100 switch(j) { 101 case STRTOG_Inexlo: 102 #ifdef Sudden_Underflow 103 if ((u->L[_0] & 0x7ff00000) < 0x3500000) { 104 word0(&u[1]) = word0(&u[0]) + 0x3500000; 105 word1(&u[1]) = word1(&u[0]); 106 dval(&u[1]) += ulp(&u[1]); 107 word0(&u[1]) -= 0x3500000; 108 if (!(word0(&u[1]) & 0x7ff00000)) { 109 word0(&u[1]) = sign; 110 word1(&u[1]) = 0; 111 } 112 } 113 else 114 #endif 115 dval(&u[1]) = dval(&u[0]) + ulp(&u[0]); 116 break; 117 case STRTOG_Inexhi: 118 dval(&u[1]) = dval(&u[0]); 119 #ifdef Sudden_Underflow 120 if ((word0(&u[0]) & 0x7ff00000) < 0x3500000) { 121 word0(&u[0]) += 0x3500000; 122 dval(&u[0]) -= ulpdown(u); 123 word0(&u[0]) -= 0x3500000; 124 if (!(word0(&u[0]) & 0x7ff00000)) { 125 word0(&u[0]) = sign; 126 word1(&u[0]) = 0; 127 } 128 } 129 else 130 #endif 131 dval(&u[0]) -= ulpdown(u); 132 break; 133 default: 134 dval(&u[1]) = dval(&u[0]); 135 } 136 break; 137 138 case STRTOG_Infinite: 139 word0(&u[0]) = word0(&u[1]) = sign | 0x7ff00000; 140 word1(&u[0]) = word1(&u[1]) = 0; 141 if (k & STRTOG_Inexact) { 142 if (sign) { 143 word0(&u[1]) = 0xffefffffL; 144 word1(&u[1]) = 0xffffffffL; 145 } 146 else { 147 word0(&u[0]) = 0x7fefffffL; 148 word1(&u[0]) = 0xffffffffL; 149 } 150 } 151 break; 152 153 case STRTOG_NaN: 154 u->L[0] = (u+1)->L[0] = d_QNAN0; 155 u->L[1] = (u+1)->L[1] = d_QNAN1; 156 break; 157 158 case STRTOG_NaNbits: 159 word0(&u[0]) = word0(&u[1]) = 0x7ff00000 | sign | bits[1]; 160 word1(&u[0]) = word1(&u[1]) = bits[0]; 161 } 162 return k; 163 } 164