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+/* 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;
+
+ /* An IEEE 854 infinity has an exponent with the
+ maximum possible value and a zero mantissa.
+ In Motorola's interpretation the integer bit is ignored. */
+ if ((u.ieee.exponent & 0x7fff) == 0x7fff &&
+ (u.ieee.mantissa0 & 0x7fffffff) == 0 && u.ieee.mantissa1 == 0)
+ return u.ieee.negative ? -1 : 1;
+
+ return 0;
+}
+
+weak_alias (__isinfl, isinfl);