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/* Check `long double' for Infinity. i386 FPU version.
Copyright (C) 1991, 1992, 1995 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <math.h>
#include "ieee754.h"
#undef __isinfl
#undef isinfl
/* Return 0 if VALUE is finite or NaN, +1 if it
is +Infinity, -1 if it is -Infinity. */
int
__isinfl (long double value)
{
union ieee854_long_double u;
u.d = value;
/* Intel's interpretation of the IEEE 854 standard defines Inf to
have the maximum possible exponent and the MSB of the mantissa
set. No further bit of the mantissa must be set. */
if ((u.ieee.exponent & 0x7fff) == 0x7fff &&
u.ieee.mantissa0 == 0x80000000 && u.ieee.mantissa1 == 0)
return u.ieee.negative ? -1 : 1;
return 0;
}
weak_alias (__isinfl, isinfl);
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