Update.
[glibc.git] / sysdeps / m68k / s_isinfl.c
blob1b06d47d52cce749aed5909527e118c62ee73faa
1 /* Copyright (C) 1991, 1992, 1995 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Library General Public License as
6 published by the Free Software Foundation; either version 2 of the
7 License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Library General Public License for more details.
14 You should have received a copy of the GNU Library General Public
15 License along with the GNU C Library; see the file COPYING.LIB. If
16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
17 Cambridge, MA 02139, USA. */
19 #include <math.h>
20 #include "ieee754.h"
22 #undef __isinfl
23 #undef isinfl
26 /* Return 0 if VALUE is finite or NaN, +1 if it
27 is +Infinity, -1 if it is -Infinity. */
28 int
29 __isinfl (long double value)
31 union ieee854_long_double u;
33 u.d = value;
35 /* An IEEE 854 infinity has an exponent with the
36 maximum possible value and a zero mantissa.
37 In Motorola's interpretation the integer bit is ignored. */
38 if ((u.ieee.exponent & 0x7fff) == 0x7fff &&
39 (u.ieee.mantissa0 & 0x7fffffff) == 0 && u.ieee.mantissa1 == 0)
40 return u.ieee.negative ? -1 : 1;
42 return 0;
45 weak_alias (__isinfl, isinfl);