about summary refs log tree commit diff
path: root/sysdeps/ieee754/nan.h
blob: bea98d96d4fb492efa0352708f302d056713752c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
/* `NAN' constant for IEEE 754 machines.
   Copyright (C) 1992, 1996 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., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#ifndef	_NAN_H

#define	_NAN_H	1

/* IEEE Not A Number.  */

#include <endian.h>

#if __BYTE_ORDER == __BIG_ENDIAN
#define	__nan_bytes		{ 0x7f, 0xf8, 0, 0, 0, 0, 0, 0 }
#endif
#if __BYTE_ORDER == __LITTLE_ENDIAN
#define	__nan_bytes		{ 0, 0, 0, 0, 0, 0, 0xf8, 0x7f }
#endif

#ifdef	__GNUC__
#define	NAN \
  (__extension__ ((union { unsigned char __c[8];			      \
			   double __d; })				      \
		  { __nan_bytes }).__d)
#else	/* Not GCC.  */
static CONST char __nan[8] = __nan_bytes;
#define	NAN	(*(CONST double *) __nan)
#endif	/* GCC.  */

#endif	/* nan.h */