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Diffstat (limited to 'sysdeps/mips/bits/nan.h')
-rw-r--r-- | sysdeps/mips/bits/nan.h | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/sysdeps/mips/bits/nan.h b/sysdeps/mips/bits/nan.h new file mode 100644 index 0000000..baaaa55 --- /dev/null +++ b/sysdeps/mips/bits/nan.h @@ -0,0 +1,56 @@ +/* `NAN' constant for IEEE 754 machines. + Copyright (C) 1992, 1996, 1997, 1999, 2002, 2004 + 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 (QNaN). Note that MIPS has the QNaN and SNaN patterns + reversed compared to most other architectures. The IEEE spec left + the definition of this open to implementations, and for MIPS the top + bit of the mantissa must be SET to indicate a SNaN. */ + +#if __GNUC_PREREQ(3,3) + +# define NAN (__builtin_nanf("")) + +#elif defined __GNUC__ + +# define NAN \ + (__extension__ \ + ((union { unsigned __l __attribute__((__mode__(__SI__))); float __d; }) \ + { __l: 0x7fbfffffUL }).__d) + +#else + +# include <endian.h> + +# if __BYTE_ORDER == __BIG_ENDIAN +# define __nan_bytes { 0x7f, 0xbf, 0xff, 0xff } +# endif +# if __BYTE_ORDER == __LITTLE_ENDIAN +# define __nan_bytes { 0xff, 0xff, 0xbf, 0x7f } +# endif + +static union { unsigned char __c[4]; float __d; } __nan_union = { __nan_bytes }; +# define NAN (__nan_union.__d) + +#endif /* GCC. */ |