/* `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. */