/* Header file for constants used in floating point <-> decimal conversions.

   Copyright (C) 1995-2018 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, see

   <http://www.gnu.org/licenses/>.  */

#ifndef _FPIOCONST_H

#define	_FPIOCONST_H

#include <float.h>

#include <math.h>

#include <gmp.h>

/* These values are used by __printf_fp, where they are noncritical (if the

   value is not large enough, it will just be slower); and by

   strtof/strtod/strtold, where it is critical (it's used for overflow

   detection).

   XXX These should be defined in <float.h>.  For the time being, we have the

   IEEE754 values here.  */

#if !defined __NO_LONG_DOUBLE_MATH && __LDBL_MAX_EXP__ > 1024

# define LDBL_MAX_10_EXP_LOG	12 /* = floor(log_2(LDBL_MAX_10_EXP)) */

#else

# define LDBL_MAX_10_EXP_LOG	8 /* = floor(log_2(LDBL_MAX_10_EXP)) */

#endif

#define DBL_MAX_10_EXP_LOG	8 /* = floor(log_2(DBL_MAX_10_EXP)) */

#define FLT_MAX_10_EXP_LOG	5 /* = floor(log_2(FLT_MAX_10_EXP)) */

/* On some machines, _Float128 may be ABI-distinct from long double (e.g

   IBM extended precision).  */

#include <bits/floatn.h>

#if __HAVE_DISTINCT_FLOAT128

# define FLT128_MAX_10_EXP_LOG	12 /* = floor(log_2(FLT128_MAX_10_EXP)) */

#endif

/* For strtold, we need powers of 10 up to floor (log_2 (LDBL_MANT_DIG

   - LDBL_MIN_EXP + 2)).  When _Float128 is enabled in libm and it is

   ABI-distinct from long double (e.g. on powerpc64le), we also need powers

   of 10 up to floor (log_2 (FLT128_MANT_DIG - FLT128_MIN_EXP + 2)).  */

#define FPIOCONST_HAVE_EXTENDED_RANGE \

  ((!defined __NO_LONG_DOUBLE_MATH && __LDBL_MAX_EXP__ > 1024) \

   || __HAVE_DISTINCT_FLOAT128)

#if FPIOCONST_HAVE_EXTENDED_RANGE

# define FPIOCONST_POW10_ARRAY_SIZE	15

#else

# define FPIOCONST_POW10_ARRAY_SIZE	11

#endif

/* The array with the number representation. */

extern const mp_limb_t __tens[] attribute_hidden;

/* Table of powers of ten.  This is used by __printf_fp and by

   strtof/strtod/strtold.  */

struct mp_power

  {

    size_t arrayoff;		/* Offset in `__tens'.  */

    mp_size_t arraysize;	/* Size of the array.  */

    int p_expo;			/* Exponent of the number 10^(2^i).  */

    int m_expo;			/* Exponent of the number 10^-(2^i-1).  */

  };

extern const struct mp_power _fpioconst_pow10[FPIOCONST_POW10_ARRAY_SIZE]

     attribute_hidden;

/* The constants in the array `_fpioconst_pow10' have an offset.  */

#if BITS_PER_MP_LIMB == 32

# define _FPIO_CONST_OFFSET	2

#else

# define _FPIO_CONST_OFFSET	1

#endif

#endif	/* fpioconst.h */