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+/* `NAN' constant for IEEE 754 machines.
+
+Copyright (C) 1992 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., 675 Mass Ave,
+Cambridge, MA 02139, 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 */