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d216d7d248
* .gitignore: Add lib/ieee754.h. * admin/merge-gnulib (GNULIB_MODULES): Add ieee754-h. * configure.ac: Remove ieee754.h check, as Gnulib now does that. * etc/NEWS: Mention this. * lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate. * lib/ieee754.in.h, m4/ieee754-h.m4: New files, from Gnulib. * src/lisp.h (IEEE_FLOATING_POINT): Now a macro so that it can be used in #if. * src/lread.c, src/print.c: Include <ieee754.h> if IEEE_FLOATING_POINT, not if HAVE_IEEE754_H. * src/lread.c (string_to_number): * src/print.c (float_to_string): Process NaNs only on IEEE hosts, and assume <ieee754.h> in that case.
223 lines
5.3 KiB
C
223 lines
5.3 KiB
C
/* Copyright (C) 1992-2018 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public
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License as published by the Free Software Foundation; either
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version 3 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef _IEEE754_H
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#define _IEEE754_H 1
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#ifndef _GL_GNULIB_HEADER
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/* Ordinary glibc usage. */
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# include <features.h>
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# include <endian.h>
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#else
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/* Gnulib usage. */
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# ifndef __BEGIN_DECLS
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# ifdef __cplusplus
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# define __BEGIN_DECLS extern "C" {
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# define __END_DECLS }
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# else
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# define __BEGIN_DECLS
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# define __END_DECLS
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# endif
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# endif
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# ifndef __FLOAT_WORD_ORDER
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# define __LITTLE_ENDIAN 1234
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# define __BIG_ENDIAN 4321
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# ifdef WORDS_BIGENDIAN
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# define __BYTE_ORDER __BIG_ENDIAN
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# else
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# define __BYTE_ORDER __LITTLE_ENDIAN
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# endif
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# define __FLOAT_WORD_ORDER __BYTE_ORDER
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# endif
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#endif
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__BEGIN_DECLS
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union ieee754_float
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{
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float f;
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/* This is the IEEE 754 single-precision format. */
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struct
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{
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#if __BYTE_ORDER == __BIG_ENDIAN
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unsigned int negative:1;
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unsigned int exponent:8;
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unsigned int mantissa:23;
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#endif /* Big endian. */
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#if __BYTE_ORDER == __LITTLE_ENDIAN
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unsigned int mantissa:23;
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unsigned int exponent:8;
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unsigned int negative:1;
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#endif /* Little endian. */
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} ieee;
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/* This format makes it easier to see if a NaN is a signalling NaN. */
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struct
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{
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#if __BYTE_ORDER == __BIG_ENDIAN
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unsigned int negative:1;
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unsigned int exponent:8;
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unsigned int quiet_nan:1;
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unsigned int mantissa:22;
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#endif /* Big endian. */
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#if __BYTE_ORDER == __LITTLE_ENDIAN
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unsigned int mantissa:22;
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unsigned int quiet_nan:1;
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unsigned int exponent:8;
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unsigned int negative:1;
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#endif /* Little endian. */
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} ieee_nan;
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};
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#define IEEE754_FLOAT_BIAS 0x7f /* Added to exponent. */
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union ieee754_double
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{
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double d;
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/* This is the IEEE 754 double-precision format. */
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struct
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{
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#if __BYTE_ORDER == __BIG_ENDIAN
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unsigned int negative:1;
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unsigned int exponent:11;
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/* Together these comprise the mantissa. */
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unsigned int mantissa0:20;
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unsigned int mantissa1:32;
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#endif /* Big endian. */
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#if __BYTE_ORDER == __LITTLE_ENDIAN
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# if __FLOAT_WORD_ORDER == __BIG_ENDIAN
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unsigned int mantissa0:20;
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unsigned int exponent:11;
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unsigned int negative:1;
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unsigned int mantissa1:32;
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# else
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/* Together these comprise the mantissa. */
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unsigned int mantissa1:32;
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unsigned int mantissa0:20;
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unsigned int exponent:11;
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unsigned int negative:1;
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# endif
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#endif /* Little endian. */
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} ieee;
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/* This format makes it easier to see if a NaN is a signalling NaN. */
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struct
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{
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#if __BYTE_ORDER == __BIG_ENDIAN
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unsigned int negative:1;
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unsigned int exponent:11;
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unsigned int quiet_nan:1;
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/* Together these comprise the mantissa. */
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unsigned int mantissa0:19;
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unsigned int mantissa1:32;
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#else
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# if __FLOAT_WORD_ORDER == __BIG_ENDIAN
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unsigned int mantissa0:19;
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unsigned int quiet_nan:1;
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unsigned int exponent:11;
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unsigned int negative:1;
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unsigned int mantissa1:32;
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# else
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/* Together these comprise the mantissa. */
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unsigned int mantissa1:32;
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unsigned int mantissa0:19;
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unsigned int quiet_nan:1;
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unsigned int exponent:11;
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unsigned int negative:1;
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# endif
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#endif
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} ieee_nan;
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};
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#define IEEE754_DOUBLE_BIAS 0x3ff /* Added to exponent. */
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union ieee854_long_double
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{
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long double d;
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/* This is the IEEE 854 double-extended-precision format. */
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struct
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{
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#if __BYTE_ORDER == __BIG_ENDIAN
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unsigned int negative:1;
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unsigned int exponent:15;
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unsigned int empty:16;
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unsigned int mantissa0:32;
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unsigned int mantissa1:32;
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#endif
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#if __BYTE_ORDER == __LITTLE_ENDIAN
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# if __FLOAT_WORD_ORDER == __BIG_ENDIAN
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unsigned int exponent:15;
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unsigned int negative:1;
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unsigned int empty:16;
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unsigned int mantissa0:32;
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unsigned int mantissa1:32;
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# else
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unsigned int mantissa1:32;
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unsigned int mantissa0:32;
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unsigned int exponent:15;
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unsigned int negative:1;
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unsigned int empty:16;
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# endif
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#endif
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} ieee;
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/* This is for NaNs in the IEEE 854 double-extended-precision format. */
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struct
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{
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#if __BYTE_ORDER == __BIG_ENDIAN
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unsigned int negative:1;
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unsigned int exponent:15;
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unsigned int empty:16;
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unsigned int one:1;
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unsigned int quiet_nan:1;
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unsigned int mantissa0:30;
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unsigned int mantissa1:32;
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#endif
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#if __BYTE_ORDER == __LITTLE_ENDIAN
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# if __FLOAT_WORD_ORDER == __BIG_ENDIAN
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unsigned int exponent:15;
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unsigned int negative:1;
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unsigned int empty:16;
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unsigned int mantissa0:30;
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unsigned int quiet_nan:1;
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unsigned int one:1;
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unsigned int mantissa1:32;
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# else
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unsigned int mantissa1:32;
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unsigned int mantissa0:30;
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unsigned int quiet_nan:1;
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unsigned int one:1;
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unsigned int exponent:15;
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unsigned int negative:1;
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unsigned int empty:16;
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# endif
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#endif
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} ieee_nan;
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};
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#define IEEE854_LONG_DOUBLE_BIAS 0x3fff
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__END_DECLS
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#endif /* ieee754.h */
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