| /* `NAN' constant for IEEE 754 machines. |
| Copyright (C) 1992,1996,1997,1999,2004,2006 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. */ |
| |
| #if __GNUC_PREREQ(3,3) |
| |
| # define NAN (__builtin_nanf ("")) |
| |
| #elif defined __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 |
| __attribute_used__ = { __nan_bytes }; |
| # define NAN (__nan_union.__d) |
| |
| #endif /* GCC. */ |
