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/* 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
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.
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
Lesser General Public License for more details.
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. */
#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;
}
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