83 lines
2.4 KiB
C
Executable File
83 lines
2.4 KiB
C
Executable File
/****************************************************************
|
|
|
|
The author of this software is David M. Gay.
|
|
|
|
Copyright (C) 2004 by David M. Gay.
|
|
All Rights Reserved
|
|
Based on material in the rest of /netlib/fp/gdota.tar.gz,
|
|
which is copyright (C) 1998, 2000 by Lucent Technologies.
|
|
|
|
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.
|
|
|
|
****************************************************************/
|
|
|
|
/* This is a variant of strtod that works on Intel ia32 systems */
|
|
/* with the default extended-precision arithmetic -- it does not */
|
|
/* require setting the precision control to 53 bits. */
|
|
|
|
/* Please send bug reports to David M. Gay (dmg at acm dot org,
|
|
* with " at " changed at "@" and " dot " changed to "."). */
|
|
|
|
#include "gdtoaimp.h"
|
|
|
|
double __strtod (const char *s, char **sp)
|
|
{
|
|
static FPI fpi = { 53, 1-1023-53+1, 2046-1023-53+1, 1, SI };
|
|
ULong bits[2];
|
|
Long exp;
|
|
int k;
|
|
union { ULong L[2]; double d; } u;
|
|
|
|
k = __strtodg(s, sp, &fpi, &exp, bits);
|
|
switch(k & STRTOG_Retmask) {
|
|
case STRTOG_NoNumber:
|
|
case STRTOG_Zero:
|
|
u.L[0] = u.L[1] = 0;
|
|
break;
|
|
|
|
case STRTOG_Normal:
|
|
u.L[_1] = bits[0];
|
|
u.L[_0] = (bits[1] & ~0x100000) | ((exp + 0x3ff + 52) << 20);
|
|
break;
|
|
|
|
case STRTOG_Denormal:
|
|
u.L[_1] = bits[0];
|
|
u.L[_0] = bits[1];
|
|
break;
|
|
|
|
case STRTOG_Infinite:
|
|
u.L[_0] = 0x7ff00000;
|
|
u.L[_1] = 0;
|
|
break;
|
|
|
|
case STRTOG_NaN:
|
|
u.L[0] = d_QNAN0;
|
|
u.L[1] = d_QNAN1;
|
|
break;
|
|
|
|
case STRTOG_NaNbits:
|
|
u.L[_0] = 0x7ff00000 | bits[1];
|
|
u.L[_1] = bits[0];
|
|
}
|
|
if (k & STRTOG_Neg)
|
|
u.L[_0] |= 0x80000000L;
|
|
return u.d;
|
|
}
|