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 <msvcrt/math.h>
20 #include <msvcrt/float.h>
21 #include <msvcrt/internal/ieee.h>
27 int _isnan(double __x)
29 double_t* x = (double_t*)&__x;
30 return (x->exponent == 0x7ff && (x->mantissah != 0 || x->mantissal != 0));
33 int _isnanl(long double __x)
35 /* Intel's extended format has the normally implicit 1 explicit
38 long_double_t* x = (long_double_t*)&__x;
41 /* IEEE 854 NaN's have the maximum possible
42 exponent and a nonzero mantissa. */
44 return (( x->exponent == 0x7fff)
45 && ((x->mantissah & 0x80000000) != 0)
46 && ((x->mantissah & (unsigned int)0x7fffffff) != 0 || x->mantissal != 0));
49 int _isinf(double __x)
51 double_t* x = (double_t*)&__x;
52 return (x->exponent == 0x7ff && (x->mantissah == 0 && x->mantissal == 0));
63 int _isinfl(long double __x)
65 /* Intel's extended format has the normally implicit 1 explicit
68 long_double_t* x = (long_double_t*)&__x;
71 /* An IEEE 854 infinity has an exponent with the
72 maximum possible value and a zero mantissa. */
75 if (x->exponent == 0x7fff && ((x->mantissah == 0x80000000) && x->mantissal == 0))
76 return x->sign ? -1 : 1;