| /**************************************************************** |
| |
| The author of this software is David M. Gay. |
| |
| Copyright (C) 1998, 2000 by Lucent Technologies |
| All Rights Reserved |
| |
| Permission to use, copy, modify, and distribute this software and |
| its documentation for any purpose and without fee is hereby |
| granted, provided that the above copyright notice appear in all |
| copies and that both that the copyright notice and this |
| permission notice and warranty disclaimer appear in supporting |
| documentation, and that the name of Lucent or any of its entities |
| not be used in advertising or publicity pertaining to |
| distribution of the software without specific, written prior |
| permission. |
| |
| LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, |
| INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. |
| IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY |
| SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER |
| IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, |
| ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF |
| THIS SOFTWARE. |
| |
| ****************************************************************/ |
| |
| /* Please send bug reports to |
| David M. Gay |
| Bell Laboratories, Room 2C-463 |
| 600 Mountain Avenue |
| Murray Hill, NJ 07974-0636 |
| U.S.A. |
| dmg@bell-labs.com |
| */ |
| |
| #include "gdtoaimp.h" |
| |
| static double |
| #ifdef KR_headers |
| ulpdown(d) double *d; |
| #else |
| ulpdown(double *d) |
| #endif |
| { |
| double u; |
| ULong *L = (ULong*)d; |
| |
| u = ulp(*d); |
| if (!(L[_1] | L[_0] & 0xfffff) |
| && (L[_0] & 0x7ff00000) > 0x00100000) |
| u *= 0.5; |
| return u; |
| } |
| |
| int |
| #ifdef KR_headers |
| strtodI(s, sp, dd) CONST char *s; char **sp; double *dd; |
| #else |
| strtodI(CONST char *s, char **sp, double *dd) |
| #endif |
| { |
| #ifdef Sudden_Underflow |
| static FPI fpi = { 53, 1-1023-53+1, 2046-1023-53+1, 1, 1 }; |
| #else |
| static FPI fpi = { 53, 1-1023-53+1, 2046-1023-53+1, 1, 0 }; |
| #endif |
| ULong bits[2], sign; |
| Long exp; |
| int j, k; |
| typedef union { |
| double d[2]; |
| ULong L[4]; |
| } U; |
| U *u; |
| |
| k = strtodg(s, sp, &fpi, &exp, bits); |
| u = (U*)dd; |
| sign = k & STRTOG_Neg ? 0x80000000L : 0; |
| switch(k & STRTOG_Retmask) { |
| case STRTOG_NoNumber: |
| u->d[0] = u->d[1] = 0.; |
| break; |
| |
| case STRTOG_Zero: |
| u->d[0] = u->d[1] = 0.; |
| #ifdef Sudden_Underflow |
| if (k & STRTOG_Inexact) { |
| if (sign) |
| u->L[_0] = 0x80100000L; |
| else |
| u->L[2+_0] = 0x100000L; |
| } |
| break; |
| #else |
| goto contain; |
| #endif |
| |
| case STRTOG_Denormal: |
| u->L[_1] = bits[0]; |
| u->L[_0] = bits[1]; |
| goto contain; |
| |
| case STRTOG_Normal: |
| u->L[_1] = bits[0]; |
| u->L[_0] = (bits[1] & ~0x100000) | ((exp + 0x3ff + 52) << 20); |
| contain: |
| j = k & STRTOG_Inexact; |
| if (sign) { |
| u->L[_0] |= sign; |
| j = STRTOG_Inexact - j; |
| } |
| switch(j) { |
| case STRTOG_Inexlo: |
| #ifdef Sudden_Underflow |
| if ((u->L[_0] & 0x7ff00000) < 0x3500000) { |
| u->L[2+_0] = u->L[_0] + 0x3500000; |
| u->L[2+_1] = u->L[_1]; |
| u->d[1] += ulp(u->d[1]); |
| u->L[2+_0] -= 0x3500000; |
| if (!(u->L[2+_0] & 0x7ff00000)) { |
| u->L[2+_0] = sign; |
| u->L[2+_1] = 0; |
| } |
| } |
| else |
| #endif |
| u->d[1] = u->d[0] + ulp(u->d[0]); |
| break; |
| case STRTOG_Inexhi: |
| u->d[1] = u->d[0]; |
| #ifdef Sudden_Underflow |
| if ((u->L[_0] & 0x7ff00000) < 0x3500000) { |
| u->L[_0] += 0x3500000; |
| u->d[0] -= ulpdown(u->d); |
| u->L[_0] -= 0x3500000; |
| if (!(u->L[_0] & 0x7ff00000)) { |
| u->L[_0] = sign; |
| u->L[_1] = 0; |
| } |
| } |
| else |
| #endif |
| u->d[0] -= ulpdown(u->d); |
| break; |
| default: |
| u->d[1] = u->d[0]; |
| } |
| break; |
| |
| case STRTOG_Infinite: |
| u->L[_0] = u->L[2+_0] = sign | 0x7ff00000; |
| u->L[_1] = u->L[2+_1] = 0; |
| if (k & STRTOG_Inexact) { |
| if (sign) { |
| u->L[2+_0] = 0xffefffffL; |
| u->L[2+_1] = 0xffffffffL; |
| } |
| else { |
| u->L[_0] = 0x7fefffffL; |
| u->L[_1] = 0xffffffffL; |
| } |
| } |
| break; |
| |
| case STRTOG_NaN: |
| u->L[_0] = u->L[2+_0] = 0x7fffffff | sign; |
| u->L[_1] = u->L[2+_1] = (ULong)-1; |
| break; |
| |
| case STRTOG_NaNbits: |
| u->L[_0] = u->L[2+_0] = 0x7ff00000 | sign | bits[1]; |
| u->L[_1] = u->L[2+_1] = bits[0]; |
| } |
| return k; |
| } |