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- /* `NAN' constant for IEEE 754 machines.
- Copyright (C) 1992, 1996, 1997, 1999 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 Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 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
- Lesser General Public License for more details.
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, write to the Free
- Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- 02111-1307 USA. */
- #ifndef _MATH_H
- # error "Never use <bits/nan.h> directly; include <math.h> instead."
- #endif
- /* IEEE Not A Number. */
- #ifdef __GNUC__
- # define NAN \
- (__extension__ \
- ((union { unsigned __l __attribute__((__mode__(__SI__))); float __d; }) \
- { __l: 0x7fc00000UL }).__d)
- #else
- # include <endian.h>
- # if __BYTE_ORDER == __BIG_ENDIAN
- # define __nan_bytes { 0x7f, 0xc0, 0, 0 }
- # endif
- # if __BYTE_ORDER == __LITTLE_ENDIAN
- # define __nan_bytes { 0, 0, 0xc0, 0x7f }
- # endif
- static union { unsigned char __c[4]; float __d; } __nan_union = { __nan_bytes };
- # define NAN (__nan_union.__d)
- #endif /* GCC. */
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