diff options
Diffstat (limited to 'libc/sysdeps/linux/common/bits/nan.h')
-rw-r--r-- | libc/sysdeps/linux/common/bits/nan.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/common/bits/nan.h b/libc/sysdeps/linux/common/bits/nan.h new file mode 100644 index 000000000..6d88b551b --- /dev/null +++ b/libc/sysdeps/linux/common/bits/nan.h @@ -0,0 +1,48 @@ +/* `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. */ |