1 /* $NetBSD: strtopdd.c,v 1.1.1.1 2006/01/25 15:18:53 kleink Exp $ */ 2 3 /**************************************************************** 4 5 The author of this software is David M. Gay. 6 7 Copyright (C) 1998, 2000 by Lucent Technologies 8 All Rights Reserved 9 10 Permission to use, copy, modify, and distribute this software and 11 its documentation for any purpose and without fee is hereby 12 granted, provided that the above copyright notice appear in all 13 copies and that both that the copyright notice and this 14 permission notice and warranty disclaimer appear in supporting 15 documentation, and that the name of Lucent or any of its entities 16 not be used in advertising or publicity pertaining to 17 distribution of the software without specific, written prior 18 permission. 19 20 LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 21 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. 22 IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY 23 SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 24 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER 25 IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, 26 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF 27 THIS SOFTWARE. 28 29 ****************************************************************/ 30 31 /* Please send bug reports to David M. Gay (dmg at acm dot org, 32 * with " at " changed at "@" and " dot " changed to "."). */ 33 34 #include "gdtoaimp.h" 35 36 int 37 #ifdef KR_headers 38 strtopdd(s, sp, dd) CONST char *s; char **sp; double *dd; 39 #else 40 strtopdd(CONST char *s, char **sp, double *dd) 41 #endif 42 { 43 #ifdef Sudden_Underflow 44 static FPI fpi = { 106, 1-1023, 2046-1023-106+1, 1, 1 }; 45 #else 46 static FPI fpi = { 106, 1-1023-53+1, 2046-1023-106+1, 1, 0 }; 47 #endif 48 ULong bits[4]; 49 Long exp; 50 int i, j, rv; 51 typedef union { 52 double d[2]; 53 ULong L[4]; 54 } U; 55 U *u; 56 57 rv = strtodg(s, sp, &fpi, &exp, bits); 58 u = (U*)dd; 59 switch(rv & STRTOG_Retmask) { 60 case STRTOG_NoNumber: 61 case STRTOG_Zero: 62 u->d[0] = u->d[1] = 0.; 63 break; 64 65 case STRTOG_Normal: 66 u->L[_1] = (bits[1] >> 21 | bits[2] << 11) & 0xffffffffL; 67 u->L[_0] = bits[2] >> 21 | bits[3] << 11 & 0xfffff 68 | exp + 0x3ff + 105 << 20; 69 exp += 0x3ff + 52; 70 if (bits[1] &= 0x1fffff) { 71 i = hi0bits(bits[1]) - 11; 72 if (i >= exp) { 73 i = exp - 1; 74 exp = 0; 75 } 76 else 77 exp -= i; 78 if (i > 0) { 79 bits[1] = bits[1] << i | bits[0] >> 32-i; 80 bits[0] = bits[0] << i & 0xffffffffL; 81 } 82 } 83 else if (bits[0]) { 84 i = hi0bits(bits[0]) + 21; 85 if (i >= exp) { 86 i = exp - 1; 87 exp = 0; 88 } 89 else 90 exp -= i; 91 if (i < 32) { 92 bits[1] = bits[0] >> 32 - i; 93 bits[0] = bits[0] << i & 0xffffffffL; 94 } 95 else { 96 bits[1] = bits[0] << i - 32; 97 bits[0] = 0; 98 } 99 } 100 else { 101 u->L[2] = u->L[3] = 0; 102 break; 103 } 104 u->L[2+_1] = bits[0]; 105 u->L[2+_0] = bits[1] & 0xfffff | exp << 20; 106 break; 107 108 case STRTOG_Denormal: 109 if (bits[3]) 110 goto nearly_normal; 111 if (bits[2]) 112 goto partly_normal; 113 if (bits[1] & 0xffe00000) 114 goto hardly_normal; 115 /* completely denormal */ 116 u->L[2] = u->L[3] = 0; 117 u->L[_1] = bits[0]; 118 u->L[_0] = bits[1]; 119 break; 120 121 nearly_normal: 122 i = hi0bits(bits[3]) - 11; /* i >= 12 */ 123 j = 32 - i; 124 u->L[_0] = (bits[3] << i | bits[2] >> j) & 0xfffff 125 | 65 - i << 20; 126 u->L[_1] = (bits[2] << i | bits[1] >> j) & 0xffffffffL; 127 u->L[2+_0] = bits[1] & (1L << j) - 1; 128 u->L[2+_1] = bits[0]; 129 break; 130 131 partly_normal: 132 i = hi0bits(bits[2]) - 11; 133 if (i < 0) { 134 j = -i; 135 i += 32; 136 u->L[_0] = bits[2] >> j & 0xfffff | (33 + j) << 20; 137 u->L[_1] = (bits[2] << i | bits[1] >> j) & 0xffffffffL; 138 u->L[2+_0] = bits[1] & (1L << j) - 1; 139 u->L[2+_1] = bits[0]; 140 break; 141 } 142 if (i == 0) { 143 u->L[_0] = bits[2] & 0xfffff | 33 << 20; 144 u->L[_1] = bits[1]; 145 u->L[2+_0] = 0; 146 u->L[2+_1] = bits[0]; 147 break; 148 } 149 j = 32 - i; 150 u->L[_0] = (bits[2] << i | bits[1] >> j) & 0xfffff 151 | j + 1 << 20; 152 u->L[_1] = (bits[1] << i | bits[0] >> j) & 0xffffffffL; 153 u->L[2+_0] = 0; 154 u->L[2+_1] = bits[0] & (1L << j) - 1; 155 break; 156 157 hardly_normal: 158 j = 11 - hi0bits(bits[1]); 159 i = 32 - j; 160 u->L[_0] = bits[1] >> j & 0xfffff | j + 1 << 20; 161 u->L[_1] = (bits[1] << i | bits[0] >> j) & 0xffffffffL; 162 u->L[2+_0] = 0; 163 u->L[2+_1] = bits[0] & (1L << j) - 1; 164 break; 165 166 case STRTOG_Infinite: 167 u->L[_0] = u->L[2+_0] = 0x7ff00000; 168 u->L[_1] = u->L[2+_1] = 0; 169 break; 170 171 case STRTOG_NaN: 172 u->L[0] = u->L[2] = d_QNAN0; 173 u->L[1] = u->L[3] = d_QNAN1; 174 } 175 if (rv & STRTOG_Neg) { 176 u->L[ _0] |= 0x80000000L; 177 u->L[2+_0] |= 0x80000000L; 178 } 179 return rv; 180 } 181