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Diffstat (limited to 'lib/ieee754.in.h')
| -rw-r--r-- | lib/ieee754.in.h | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/lib/ieee754.in.h b/lib/ieee754.in.h new file mode 100644 index 00000000000..a079e59d791 --- /dev/null +++ b/lib/ieee754.in.h @@ -0,0 +1,222 @@ +/* Copyright (C) 1992-2019 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 General Public + License as published by the Free Software Foundation; either + version 3 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 + General Public License for more details. + + You should have received a copy of the GNU General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#ifndef _IEEE754_H + +#define _IEEE754_H 1 + +#ifndef _GL_GNULIB_HEADER +/* Ordinary glibc usage. */ +# include <features.h> +# include <endian.h> +#else +/* Gnulib usage. */ +# ifndef __BEGIN_DECLS +# ifdef __cplusplus +# define __BEGIN_DECLS extern "C" { +# define __END_DECLS } +# else +# define __BEGIN_DECLS +# define __END_DECLS +# endif +# endif +# ifndef __FLOAT_WORD_ORDER +# define __LITTLE_ENDIAN 1234 +# define __BIG_ENDIAN 4321 +# ifdef WORDS_BIGENDIAN +# define __BYTE_ORDER __BIG_ENDIAN +# else +# define __BYTE_ORDER __LITTLE_ENDIAN +# endif +# define __FLOAT_WORD_ORDER __BYTE_ORDER +# endif +#endif + +__BEGIN_DECLS + +union ieee754_float + { + float f; + + /* This is the IEEE 754 single-precision format. */ + struct + { +#if __BYTE_ORDER == __BIG_ENDIAN + unsigned int negative:1; + unsigned int exponent:8; + unsigned int mantissa:23; +#endif /* Big endian. */ +#if __BYTE_ORDER == __LITTLE_ENDIAN + unsigned int mantissa:23; + unsigned int exponent:8; + unsigned int negative:1; +#endif /* Little endian. */ + } ieee; + + /* This format makes it easier to see if a NaN is a signalling NaN. */ + struct + { +#if __BYTE_ORDER == __BIG_ENDIAN + unsigned int negative:1; + unsigned int exponent:8; + unsigned int quiet_nan:1; + unsigned int mantissa:22; +#endif /* Big endian. */ +#if __BYTE_ORDER == __LITTLE_ENDIAN + unsigned int mantissa:22; + unsigned int quiet_nan:1; + unsigned int exponent:8; + unsigned int negative:1; +#endif /* Little endian. */ + } ieee_nan; + }; + +#define IEEE754_FLOAT_BIAS 0x7f /* Added to exponent. */ + + +union ieee754_double + { + double d; + + /* This is the IEEE 754 double-precision format. */ + struct + { +#if __BYTE_ORDER == __BIG_ENDIAN + unsigned int negative:1; + unsigned int exponent:11; + /* Together these comprise the mantissa. */ + unsigned int mantissa0:20; + unsigned int mantissa1:32; +#endif /* Big endian. */ +#if __BYTE_ORDER == __LITTLE_ENDIAN +# if __FLOAT_WORD_ORDER == __BIG_ENDIAN + unsigned int mantissa0:20; + unsigned int exponent:11; + unsigned int negative:1; + unsigned int mantissa1:32; +# else + /* Together these comprise the mantissa. */ + unsigned int mantissa1:32; + unsigned int mantissa0:20; + unsigned int exponent:11; + unsigned int negative:1; +# endif +#endif /* Little endian. */ + } ieee; + + /* This format makes it easier to see if a NaN is a signalling NaN. */ + struct + { +#if __BYTE_ORDER == __BIG_ENDIAN + unsigned int negative:1; + unsigned int exponent:11; + unsigned int quiet_nan:1; + /* Together these comprise the mantissa. */ + unsigned int mantissa0:19; + unsigned int mantissa1:32; +#else +# if __FLOAT_WORD_ORDER == __BIG_ENDIAN + unsigned int mantissa0:19; + unsigned int quiet_nan:1; + unsigned int exponent:11; + unsigned int negative:1; + unsigned int mantissa1:32; +# else + /* Together these comprise the mantissa. */ + unsigned int mantissa1:32; + unsigned int mantissa0:19; + unsigned int quiet_nan:1; + unsigned int exponent:11; + unsigned int negative:1; +# endif +#endif + } ieee_nan; + }; + +#define IEEE754_DOUBLE_BIAS 0x3ff /* Added to exponent. */ + + +union ieee854_long_double + { + long double d; + + /* This is the IEEE 854 double-extended-precision format. */ + struct + { +#if __BYTE_ORDER == __BIG_ENDIAN + unsigned int negative:1; + unsigned int exponent:15; + unsigned int empty:16; + unsigned int mantissa0:32; + unsigned int mantissa1:32; +#endif +#if __BYTE_ORDER == __LITTLE_ENDIAN +# if __FLOAT_WORD_ORDER == __BIG_ENDIAN + unsigned int exponent:15; + unsigned int negative:1; + unsigned int empty:16; + unsigned int mantissa0:32; + unsigned int mantissa1:32; +# else + unsigned int mantissa1:32; + unsigned int mantissa0:32; + unsigned int exponent:15; + unsigned int negative:1; + unsigned int empty:16; +# endif +#endif + } ieee; + + /* This is for NaNs in the IEEE 854 double-extended-precision format. */ + struct + { +#if __BYTE_ORDER == __BIG_ENDIAN + unsigned int negative:1; + unsigned int exponent:15; + unsigned int empty:16; + unsigned int one:1; + unsigned int quiet_nan:1; + unsigned int mantissa0:30; + unsigned int mantissa1:32; +#endif +#if __BYTE_ORDER == __LITTLE_ENDIAN +# if __FLOAT_WORD_ORDER == __BIG_ENDIAN + unsigned int exponent:15; + unsigned int negative:1; + unsigned int empty:16; + unsigned int mantissa0:30; + unsigned int quiet_nan:1; + unsigned int one:1; + unsigned int mantissa1:32; +# else + unsigned int mantissa1:32; + unsigned int mantissa0:30; + unsigned int quiet_nan:1; + unsigned int one:1; + unsigned int exponent:15; + unsigned int negative:1; + unsigned int empty:16; +# endif +#endif + } ieee_nan; + }; + +#define IEEE854_LONG_DOUBLE_BIAS 0x3fff + +__END_DECLS + +#endif /* ieee754.h */ |