195 lines
7.7 KiB
C
195 lines
7.7 KiB
C
/* A correct <float.h>.
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Copyright (C) 2007-2022 Free Software Foundation, Inc.
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This file is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as
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published by the Free Software Foundation; either version 2.1 of the
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License, or (at your option) any later version.
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This file 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
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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#ifndef _@GUARD_PREFIX@_FLOAT_H
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#if __GNUC__ >= 3
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@PRAGMA_SYSTEM_HEADER@
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#endif
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@PRAGMA_COLUMNS@
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/* The include_next requires a split double-inclusion guard. */
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#@INCLUDE_NEXT@ @NEXT_FLOAT_H@
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#ifndef _@GUARD_PREFIX@_FLOAT_H
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#define _@GUARD_PREFIX@_FLOAT_H
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/* 'long double' properties. */
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#if defined __i386__ && (defined __BEOS__ || defined __OpenBSD__)
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/* Number of mantissa units, in base FLT_RADIX. */
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# undef LDBL_MANT_DIG
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# define LDBL_MANT_DIG 64
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/* Number of decimal digits that is sufficient for representing a number. */
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# undef LDBL_DIG
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# define LDBL_DIG 18
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/* x-1 where x is the smallest representable number > 1. */
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# undef LDBL_EPSILON
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# define LDBL_EPSILON 1.0842021724855044340E-19L
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/* Minimum e such that FLT_RADIX^(e-1) is a normalized number. */
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# undef LDBL_MIN_EXP
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# define LDBL_MIN_EXP (-16381)
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/* Maximum e such that FLT_RADIX^(e-1) is a representable finite number. */
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# undef LDBL_MAX_EXP
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# define LDBL_MAX_EXP 16384
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/* Minimum positive normalized number. */
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# undef LDBL_MIN
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# define LDBL_MIN 3.3621031431120935063E-4932L
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/* Maximum representable finite number. */
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# undef LDBL_MAX
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# define LDBL_MAX 1.1897314953572317650E+4932L
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/* Minimum e such that 10^e is in the range of normalized numbers. */
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# undef LDBL_MIN_10_EXP
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# define LDBL_MIN_10_EXP (-4931)
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/* Maximum e such that 10^e is in the range of representable finite numbers. */
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# undef LDBL_MAX_10_EXP
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# define LDBL_MAX_10_EXP 4932
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#endif
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/* On FreeBSD/x86 6.4, the 'long double' type really has only 53 bits of
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precision in the compiler but 64 bits of precision at runtime. See
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<https://lists.gnu.org/r/bug-gnulib/2008-07/msg00063.html>. */
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#if defined __i386__ && (defined __FreeBSD__ || defined __DragonFly__)
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/* Number of mantissa units, in base FLT_RADIX. */
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# undef LDBL_MANT_DIG
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# define LDBL_MANT_DIG 64
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/* Number of decimal digits that is sufficient for representing a number. */
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# undef LDBL_DIG
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# define LDBL_DIG 18
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/* x-1 where x is the smallest representable number > 1. */
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# undef LDBL_EPSILON
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# define LDBL_EPSILON 1.084202172485504434007452800869941711426e-19L /* 2^-63 */
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/* Minimum e such that FLT_RADIX^(e-1) is a normalized number. */
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# undef LDBL_MIN_EXP
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# define LDBL_MIN_EXP (-16381)
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/* Maximum e such that FLT_RADIX^(e-1) is a representable finite number. */
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# undef LDBL_MAX_EXP
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# define LDBL_MAX_EXP 16384
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/* Minimum positive normalized number. */
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# undef LDBL_MIN
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# define LDBL_MIN 3.362103143112093506262677817321752E-4932L /* = 0x1p-16382L */
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/* Maximum representable finite number. */
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# undef LDBL_MAX
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/* LDBL_MAX is represented as { 0xFFFFFFFF, 0xFFFFFFFF, 32766 }.
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But the largest literal that GCC allows us to write is
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0x0.fffffffffffff8p16384L = { 0xFFFFF800, 0xFFFFFFFF, 32766 }.
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So, define it like this through a reference to an external variable
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const unsigned int LDBL_MAX[3] = { 0xFFFFFFFF, 0xFFFFFFFF, 32766 };
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extern const long double LDBL_MAX;
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Unfortunately, this is not a constant expression. */
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# if !GNULIB_defined_long_double_union
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union gl_long_double_union
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{
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struct { unsigned int lo; unsigned int hi; unsigned int exponent; } xd;
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long double ld;
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};
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# define GNULIB_defined_long_double_union 1
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# endif
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extern const union gl_long_double_union gl_LDBL_MAX;
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# define LDBL_MAX (gl_LDBL_MAX.ld)
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/* Minimum e such that 10^e is in the range of normalized numbers. */
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# undef LDBL_MIN_10_EXP
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# define LDBL_MIN_10_EXP (-4931)
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/* Maximum e such that 10^e is in the range of representable finite numbers. */
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# undef LDBL_MAX_10_EXP
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# define LDBL_MAX_10_EXP 4932
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#endif
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/* On AIX 7.1 with gcc 4.2, the values of LDBL_MIN_EXP, LDBL_MIN, LDBL_MAX are
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wrong.
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On Linux/PowerPC with gcc 4.4, the value of LDBL_MAX is wrong. */
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#if (defined _ARCH_PPC || defined _POWER) && defined _AIX && (LDBL_MANT_DIG == 106) && defined __GNUC__
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# undef LDBL_MIN_EXP
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# define LDBL_MIN_EXP DBL_MIN_EXP
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# undef LDBL_MIN_10_EXP
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# define LDBL_MIN_10_EXP DBL_MIN_10_EXP
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# undef LDBL_MIN
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# define LDBL_MIN 2.22507385850720138309023271733240406422e-308L /* DBL_MIN = 2^-1022 */
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#endif
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#if (defined _ARCH_PPC || defined _POWER) && (defined _AIX || defined __linux__) && (LDBL_MANT_DIG == 106) && defined __GNUC__
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# undef LDBL_MAX
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/* LDBL_MAX is represented as { 0x7FEFFFFF, 0xFFFFFFFF, 0x7C8FFFFF, 0xFFFFFFFF }.
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It is not easy to define:
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#define LDBL_MAX 1.79769313486231580793728971405302307166e308L
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is too small, whereas
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#define LDBL_MAX 1.79769313486231580793728971405302307167e308L
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is too large. Apparently a bug in GCC decimal-to-binary conversion.
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Also, I can't get values larger than
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#define LDBL63 ((long double) (1ULL << 63))
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#define LDBL882 (LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63)
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#define LDBL945 (LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63)
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#define LDBL1008 (LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63)
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#define LDBL_MAX (LDBL1008 * 65535.0L + LDBL945 * (long double) 9223372036821221375ULL + LDBL882 * (long double) 4611686018427387904ULL)
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which is represented as { 0x7FEFFFFF, 0xFFFFFFFF, 0x7C8FFFFF, 0xF8000000 }.
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So, define it like this through a reference to an external variable
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const double LDBL_MAX[2] = { DBL_MAX, DBL_MAX / (double)134217728UL / (double)134217728UL };
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extern const long double LDBL_MAX;
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or through a pointer cast
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#define LDBL_MAX \
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(*(const long double *) (double[]) { DBL_MAX, DBL_MAX / (double)134217728UL / (double)134217728UL })
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Unfortunately, this is not a constant expression, and the latter expression
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does not work well when GCC is optimizing.. */
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# if !GNULIB_defined_long_double_union
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union gl_long_double_union
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{
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struct { double hi; double lo; } dd;
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long double ld;
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};
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# define GNULIB_defined_long_double_union 1
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# endif
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extern const union gl_long_double_union gl_LDBL_MAX;
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# define LDBL_MAX (gl_LDBL_MAX.ld)
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#endif
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/* On IRIX 6.5, with cc, the value of LDBL_MANT_DIG is wrong.
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On IRIX 6.5, with gcc 4.2, the values of LDBL_MIN_EXP, LDBL_MIN, LDBL_EPSILON
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are wrong. */
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#if defined __sgi && (LDBL_MANT_DIG >= 106)
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# undef LDBL_MANT_DIG
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# define LDBL_MANT_DIG 106
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# if defined __GNUC__
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# undef LDBL_MIN_EXP
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# define LDBL_MIN_EXP DBL_MIN_EXP
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# undef LDBL_MIN_10_EXP
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# define LDBL_MIN_10_EXP DBL_MIN_10_EXP
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# undef LDBL_MIN
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# define LDBL_MIN 2.22507385850720138309023271733240406422e-308L /* DBL_MIN = 2^-1022 */
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# undef LDBL_EPSILON
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# define LDBL_EPSILON 2.46519032881566189191165176650870696773e-32L /* 2^-105 */
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# endif
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#endif
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#if @REPLACE_ITOLD@
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/* Pull in a function that fixes the 'int' to 'long double' conversion
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of glibc 2.7. */
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extern
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# ifdef __cplusplus
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"C"
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# endif
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void _Qp_itoq (long double *, int);
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static void (*_gl_float_fix_itold) (long double *, int) = _Qp_itoq;
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#endif
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#endif /* _@GUARD_PREFIX@_FLOAT_H */
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#endif /* _@GUARD_PREFIX@_FLOAT_H */
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