1999-12-29 18:11:48 +00:00
|
|
|
/* Software floating-point emulation.
|
|
|
|
Helper routine for _Q_* routines.
|
|
|
|
Simulate exceptions using double arithmetics.
|
|
|
|
Copyright (C) 1999 Free Software Foundation, Inc.
|
|
|
|
This file is part of the GNU C Library.
|
|
|
|
Contributed by Jakub Jelinek (jj@ultra.linux.cz).
|
|
|
|
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
2001-07-06 04:58:11 +00:00
|
|
|
modify it under the terms of the GNU Lesser General Public
|
|
|
|
License as published by the Free Software Foundation; either
|
|
|
|
version 2.1 of the License, or (at your option) any later version.
|
1999-12-29 18:11:48 +00:00
|
|
|
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
2001-07-06 04:58:11 +00:00
|
|
|
Lesser General Public License for more details.
|
1999-12-29 18:11:48 +00:00
|
|
|
|
2001-07-06 04:58:11 +00:00
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
|
|
License along with the GNU C Library; if not, write to the Free
|
|
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
|
|
02111-1307 USA. */
|
1999-12-29 18:11:48 +00:00
|
|
|
|
|
|
|
#include "soft-fp.h"
|
|
|
|
|
|
|
|
unsigned long long ___Q_numbers [] = {
|
|
|
|
0x0000000000000000ULL, /* Zero */
|
|
|
|
0x0010100000000000ULL, /* Very tiny number */
|
|
|
|
0x0010000000000000ULL, /* Minimum normalized number */
|
|
|
|
0x7fef000000000000ULL, /* A huge double number */
|
|
|
|
};
|
|
|
|
|
|
|
|
double ___Q_simulate_exceptions(int exceptions)
|
|
|
|
{
|
|
|
|
double d, *p = (double *)___Q_numbers;
|
|
|
|
if (exceptions & FP_EX_INVALID)
|
|
|
|
d = p[0]/p[0];
|
|
|
|
if (exceptions & FP_EX_OVERFLOW)
|
|
|
|
{
|
|
|
|
d = p[3] + p[3];
|
|
|
|
exceptions &= ~FP_EX_INEXACT;
|
|
|
|
}
|
|
|
|
if (exceptions & FP_EX_UNDERFLOW)
|
|
|
|
{
|
|
|
|
if (exceptions & FP_EX_INEXACT)
|
|
|
|
{
|
|
|
|
d = p[2] * p[2];
|
|
|
|
exceptions &= ~FP_EX_INEXACT;
|
|
|
|
}
|
|
|
|
else
|
|
|
|
d = p[1] - p[2];
|
|
|
|
}
|
|
|
|
if (exceptions & FP_EX_DIVZERO)
|
|
|
|
d = 1.0/p[0];
|
|
|
|
if (exceptions & FP_EX_INEXACT)
|
|
|
|
d = p[3] - p[2];
|
|
|
|
return d;
|
|
|
|
}
|