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>
24 int _isnan(double __x)
26 double_t * x = (double_t *)&__x;
27 return ( x->exponent == 0x7ff && ( x->mantissah != 0 || x->mantissal != 0 ));
30 int _isnanl(long double __x)
32 /* Intel's extended format has the normally implicit 1 explicit
35 long_double_t * x = (long_double_t *)&__x;
38 /* IEEE 854 NaN's have the maximum possible
39 exponent and a nonzero mantissa. */
41 return (( x->exponent == 0x7fff)
42 && ( (x->mantissah & 0x80000000) != 0)
43 && ( (x->mantissah & (unsigned int)0x7fffffff) != 0 || x->mantissal != 0 ));
46 int _isinf(double __x)
48 double_t * x = (double_t *)&__x;
49 return ( x->exponent == 0x7ff && ( x->mantissah == 0 && x->mantissal == 0 ));
52 int _finite( double x )
57 int _isinfl(long double __x)
59 /* Intel's extended format has the normally implicit 1 explicit
62 long_double_t * x = (long_double_t *)&__x;
65 /* An IEEE 854 infinity has an exponent with the
66 maximum possible value and a zero mantissa. */
69 if ( x->exponent == 0x7fff && ( (x->mantissah == 0x80000000 ) && x->mantissal == 0 ))
70 return x->sign ? -1 : 1;