gnulib/lib/float.in.h

/* A correct <float.h>.

   Copyright (C) 2007-2025 Free Software Foundation, Inc.

   This file 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.

   This file 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 this program.  If not, see <https://www.gnu.org/licenses/>.  */

#ifndef _@GUARD_PREFIX@_FLOAT_H

#if __GNUC__ >= 3
@PRAGMA_SYSTEM_HEADER@
#endif
@PRAGMA_COLUMNS@

/* The include_next requires a split double-inclusion guard.  */
#@INCLUDE_NEXT@ @NEXT_FLOAT_H@

#ifndef _@GUARD_PREFIX@_FLOAT_H
#define _@GUARD_PREFIX@_FLOAT_H

/* ============================ ISO C99 support ============================ */

/* 'long double' properties.  */

#if defined __i386__ && (defined __BEOS__ || defined __OpenBSD__)
/* Number of mantissa units, in base FLT_RADIX.  */
# undef LDBL_MANT_DIG
# define LDBL_MANT_DIG   64
/* Number of decimal digits that is sufficient for representing a number.  */
# undef LDBL_DIG
# define LDBL_DIG        18
/* x-1 where x is the smallest representable number > 1.  */
# undef LDBL_EPSILON
# define LDBL_EPSILON    1.0842021724855044340E-19L
/* Minimum e such that FLT_RADIX^(e-1) is a normalized number.  */
# undef LDBL_MIN_EXP
# define LDBL_MIN_EXP    (-16381)
/* Maximum e such that FLT_RADIX^(e-1) is a representable finite number.  */
# undef LDBL_MAX_EXP
# define LDBL_MAX_EXP    16384
/* Minimum positive normalized number.  */
# undef LDBL_MIN
# define LDBL_MIN        3.3621031431120935063E-4932L
/* Maximum representable finite number.  */
# undef LDBL_MAX
# define LDBL_MAX        1.1897314953572317650E+4932L
/* Minimum e such that 10^e is in the range of normalized numbers.  */
# undef LDBL_MIN_10_EXP
# define LDBL_MIN_10_EXP (-4931)
/* Maximum e such that 10^e is in the range of representable finite numbers.  */
# undef LDBL_MAX_10_EXP
# define LDBL_MAX_10_EXP 4932
#endif

/* On FreeBSD/x86 6.4, the 'long double' type really has only 53 bits of
   precision in the compiler but 64 bits of precision at runtime.  See
   <https://lists.gnu.org/r/bug-gnulib/2008-07/msg00063.html>.  */
#if defined __i386__ && (defined __FreeBSD__ || defined __DragonFly__)
/* Number of mantissa units, in base FLT_RADIX.  */
# undef LDBL_MANT_DIG
# define LDBL_MANT_DIG   64
/* Number of decimal digits that is sufficient for representing a number.  */
# undef LDBL_DIG
# define LDBL_DIG        18
/* x-1 where x is the smallest representable number > 1.  */
# undef LDBL_EPSILON
# define LDBL_EPSILON 1.084202172485504434007452800869941711426e-19L /* 2^-63 */
/* Minimum e such that FLT_RADIX^(e-1) is a normalized number.  */
# undef LDBL_MIN_EXP
# define LDBL_MIN_EXP    (-16381)
/* Maximum e such that FLT_RADIX^(e-1) is a representable finite number.  */
# undef LDBL_MAX_EXP
# define LDBL_MAX_EXP    16384
/* Minimum positive normalized number.  */
# undef LDBL_MIN
# define LDBL_MIN        3.362103143112093506262677817321752E-4932L /* = 0x1p-16382L */
/* Maximum representable finite number.  */
# undef LDBL_MAX
/* LDBL_MAX is represented as { 0xFFFFFFFF, 0xFFFFFFFF, 32766 }.
   But the largest literal that GCC allows us to write is
   0x0.fffffffffffff8p16384L = { 0xFFFFF800, 0xFFFFFFFF, 32766 }.
   So, define it like this through a reference to an external variable

     const unsigned int LDBL_MAX[3] = { 0xFFFFFFFF, 0xFFFFFFFF, 32766 };
     extern const long double LDBL_MAX;

   Unfortunately, this is not a constant expression.  */
# if !GNULIB_defined_long_double_union
union gl_long_double_union
  {
    struct { unsigned int lo; unsigned int hi; unsigned int exponent; } xd;
    long double ld;
  };
#  define GNULIB_defined_long_double_union 1
# endif
extern const union gl_long_double_union gl_LDBL_MAX;
# define LDBL_MAX (gl_LDBL_MAX.ld)
/* Minimum e such that 10^e is in the range of normalized numbers.  */
# undef LDBL_MIN_10_EXP
# define LDBL_MIN_10_EXP (-4931)
/* Maximum e such that 10^e is in the range of representable finite numbers.  */
# undef LDBL_MAX_10_EXP
# define LDBL_MAX_10_EXP 4932
#endif

/* On AIX 7.1 with gcc 4.2, the values of LDBL_MIN_EXP, LDBL_MIN, LDBL_MAX are
   wrong.
   On Linux/PowerPC with gcc 8.3, the values of LDBL_MAX and LDBL_EPSILON are
   wrong.
   Assume these bugs are fixed in any GCC new enough
   to define __LDBL_NORM_MAX__.  */
#if (defined _ARCH_PPC && LDBL_MANT_DIG == 106 \
     && defined __GNUC__ && !defined __LDBL_NORM_MAX__)
# undef LDBL_MIN_EXP
# define LDBL_MIN_EXP (-968)
# undef LDBL_MIN_10_EXP
# define LDBL_MIN_10_EXP (-291)
# undef LDBL_MIN
# define LDBL_MIN 0x1p-969L

/* IBM long double is tricky: it is represented as the sum of two doubles,
   and the high double must equal the sum of the two parts rounded to nearest.
   The maximum finite value for which this is true is
   { 0x1.fffffffffffffp+1023, 0x1.ffffffffffffep+969 },
   which represents 0x1.fffffffffffff7ffffffffffff8p+1023L.
   Although computations can yield representations of numbers larger than this,
   these computations are considered to have overflowed and behavior is undefined.
   See <https://gcc.gnu.org/PR120993>.  */
# undef LDBL_MAX
# define LDBL_MAX 0x1.fffffffffffff7ffffffffffff8p+1023L

/* On PowerPC platforms, 'long double' has a double-double representation.
   Up to ISO C 17, this was outside the scope of ISO C because it can represent
   numbers with mantissas of the form 1.<52 bits><many zeroes><52 bits>, such as
   1.0L + 4.94065645841246544176568792868221e-324L = 1 + 2^-1074; see
   ISO C 17 § 5.2.4.2.2.(3).
   In ISO C 23, wording has been included that makes this 'long double'
   representation compliant; see ISO C 23 § 5.2.5.3.3.(8)-(9).  In this setting,
   numbers with mantissas of the form 1.<52 bits><many zeroes><52 bits> are
   called "unnormalized".  And since LDBL_EPSILON must be normalized (per
   ISO C 23 § 5.2.5.3.3.(33)), it must be 2^-105.  */
# undef LDBL_EPSILON
# define LDBL_EPSILON 0x1p-105L
#endif

/* ============================ ISO C11 support ============================ */

/* 'float' properties */

#ifndef FLT_HAS_SUBNORM
# define FLT_HAS_SUBNORM 1
#endif
#ifndef FLT_DECIMAL_DIG
/* FLT_MANT_DIG = 24 => FLT_DECIMAL_DIG = 9 */
# define FLT_DECIMAL_DIG ((int)(FLT_MANT_DIG * 0.3010299956639812 + 2))
#endif
#if defined _AIX && !defined __GNUC__
/* On AIX, the value of FLT_TRUE_MIN in /usr/include/float.h is a 'double',
   not a 'float'.  */
# undef FLT_TRUE_MIN
#endif
#ifndef FLT_TRUE_MIN
/* FLT_MIN / 2^(FLT_MANT_DIG-1) */
# define FLT_TRUE_MIN (FLT_MIN / 8388608.0f)
#endif

/* 'double' properties */

#ifndef DBL_HAS_SUBNORM
# define DBL_HAS_SUBNORM 1
#endif
#ifndef DBL_DECIMAL_DIG
/* DBL_MANT_DIG = 53 => DBL_DECIMAL_DIG = 17 */
# define DBL_DECIMAL_DIG ((int)(DBL_MANT_DIG * 0.3010299956639812 + 2))
#endif
#ifndef DBL_TRUE_MIN
/* DBL_MIN / 2^(DBL_MANT_DIG-1) */
# define DBL_TRUE_MIN (DBL_MIN / 4503599627370496.0)
#endif

/* 'long double' properties */

#ifndef LDBL_HAS_SUBNORM
# define LDBL_HAS_SUBNORM 1
#endif
#ifndef LDBL_DECIMAL_DIG
/* LDBL_MANT_DIG = 53 => LDBL_DECIMAL_DIG = 17 */
/* LDBL_MANT_DIG = 64 => LDBL_DECIMAL_DIG = 21 */
/* LDBL_MANT_DIG = 106 => LDBL_DECIMAL_DIG = 33 */
/* LDBL_MANT_DIG = 113 => LDBL_DECIMAL_DIG = 36 */
# define LDBL_DECIMAL_DIG ((int)(LDBL_MANT_DIG * 0.3010299956639812 + 2))
#endif
#ifndef LDBL_TRUE_MIN
/* LDBL_MIN / 2^(LDBL_MANT_DIG-1) */
# if LDBL_MANT_DIG == 53
#  define LDBL_TRUE_MIN (LDBL_MIN / 4503599627370496.0L)
# elif LDBL_MANT_DIG == 64
#  if defined __i386__ && (defined __FreeBSD__ || defined __DragonFly__)
/* Work around FreeBSD/x86 problem mentioned above.  */
extern const union gl_long_double_union gl_LDBL_TRUE_MIN;
#   define LDBL_TRUE_MIN (gl_LDBL_TRUE_MIN.ld)
#  else
#   define LDBL_TRUE_MIN (LDBL_MIN / 9223372036854775808.0L)
#  endif
# elif LDBL_MANT_DIG == 106
#  define LDBL_TRUE_MIN (LDBL_MIN / 40564819207303340847894502572032.0L)
# elif LDBL_MANT_DIG == 113
#  define LDBL_TRUE_MIN (LDBL_MIN / 5192296858534827628530496329220096.0L)
# endif
#endif

/* ============================ ISO C23 support ============================ */

/* 'float' properties */

#ifndef FLT_IS_IEC_60559
# if defined __m68k__
#  define FLT_IS_IEC_60559 0
# else
#  define FLT_IS_IEC_60559 1
# endif
#endif
#ifndef FLT_NORM_MAX
# define FLT_NORM_MAX FLT_MAX
#endif
#ifndef FLT_SNAN
/* For sh, beware of <https://gcc.gnu.org/PR111814>.  */
# if ((__GNUC__ + (__GNUC_MINOR__ >= 3) > 3) || defined __clang__) && !defined __sh__
#  define FLT_SNAN __builtin_nansf ("")
# else
typedef union { unsigned int word[1]; float value; } gl_FLT_SNAN_t;
extern gl_FLT_SNAN_t gl_FLT_SNAN;
#  define FLT_SNAN (gl_FLT_SNAN.value)
#  define GNULIB_defined_FLT_SNAN 1
# endif
#endif

/* 'double' properties */

#ifndef DBL_IS_IEC_60559
# if defined __m68k__
#  define DBL_IS_IEC_60559 0
# else
#  define DBL_IS_IEC_60559 1
# endif
#endif
#ifndef DBL_NORM_MAX
# define DBL_NORM_MAX DBL_MAX
#endif
#ifndef DBL_SNAN
/* For sh, beware of <https://gcc.gnu.org/PR111814>.  */
# if ((__GNUC__ + (__GNUC_MINOR__ >= 3) > 3) || defined __clang__) && !defined __sh__
#  define DBL_SNAN __builtin_nans ("")
# else
typedef union { unsigned long long word[1]; double value; } gl_DBL_SNAN_t;
extern gl_DBL_SNAN_t gl_DBL_SNAN;
#  define DBL_SNAN (gl_DBL_SNAN.value)
#  define GNULIB_defined_DBL_SNAN 1
# endif
#endif

/* 'long double' properties */

#ifndef LDBL_IS_IEC_60559
# if defined __m68k__
#  define LDBL_IS_IEC_60559 0
# elif LDBL_MANT_DIG == 53 || LDBL_MANT_DIG == 113
#  define LDBL_IS_IEC_60559 1
# else
#  define LDBL_IS_IEC_60559 0
# endif
#endif
#ifndef LDBL_NORM_MAX
# ifdef __LDBL_NORM_MAX__
#  define LDBL_NORM_MAX __LDBL_NORM_MAX__
# elif FLT_RADIX == 2 && LDBL_MAX_EXP == 1024 && LDBL_MANT_DIG == 106
#  define LDBL_NORM_MAX 0x1.ffffffffffffffffffffffffff8p+1022L
# else
#  define LDBL_NORM_MAX LDBL_MAX
# endif
#endif
#ifndef LDBL_SNAN
/* For sh, beware of <https://gcc.gnu.org/PR111814>.  */
# if ((__GNUC__ + (__GNUC_MINOR__ >= 3) > 3) || defined __clang__) && !defined __sh__
#  define LDBL_SNAN __builtin_nansl ("")
# else
#  if LDBL_MANT_DIG == 53
typedef union { unsigned long long word[1]; long double value; } gl_LDBL_SNAN_t;
#  elif defined __m68k__
typedef union { unsigned int word[3]; long double value; } gl_LDBL_SNAN_t;
#  else
typedef union { unsigned long long word[2]; long double value; } gl_LDBL_SNAN_t;
#  endif
extern gl_LDBL_SNAN_t gl_LDBL_SNAN;
#  define LDBL_SNAN (gl_LDBL_SNAN.value)
#  define GNULIB_defined_LDBL_SNAN 1
# endif
#endif

/* ================================= Other ================================= */

#if @REPLACE_ITOLD@
/* Pull in a function that fixes the 'int' to 'long double' conversion
   of glibc 2.7.  */
extern
# ifdef __cplusplus
"C"
# endif
void _Qp_itoq (long double *, int);
static void (*_gl_float_fix_itold) (long double *, int) = _Qp_itoq;
#endif

#endif /* _@GUARD_PREFIX@_FLOAT_H */
#endif /* _@GUARD_PREFIX@_FLOAT_H */