[thirdparty/glibc.git] / stdlib / fpioconst.h

/* Header file for constants used in floating point <-> decimal conversions.
   Copyright (C) 1995-2023 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
   <https://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)).  */
#if (!defined __NO_LONG_DOUBLE_MATH && __LDBL_MAX_EXP__ > 1024) \
    || __HAVE_DISTINCT_FLOAT128
# define FPIOCONST_HAVE_EXTENDED_RANGE 1
#else
# define FPIOCONST_HAVE_EXTENDED_RANGE 0
#endif

#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 */
Commit	Line	Data
28f540f4	1	/* Header file for constants used in floating point <-> decimal conversions.
6d7e8eda	2	Copyright (C) 1995-2023 Free Software Foundation, Inc.
7cc27f44	3	This file is part of the GNU C Library.
28f540f4	4
7cc27f44	5	The GNU C Library is free software; you can redistribute it and/or
41bdb6e2 AJ	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
28f540f4	9
7cc27f44 UD	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
41bdb6e2	13	Lesser General Public License for more details.
28f540f4	14
41bdb6e2	15	You should have received a copy of the GNU Lesser General Public
59ba27a6	16	License along with the GNU C Library; if not, see
5a82c748	17	<https://www.gnu.org/licenses/>. */
28f540f4 RM	18
	19	#ifndef _FPIOCONST_H
	20	#define _FPIOCONST_H
	21
	22	#include <float.h>
76235ed4	23	#include <math.h>
264befa8	24	#include <gmp.h>
28f540f4 RM	25
	26
	27	/* These values are used by __printf_fp, where they are noncritical (if the
	28	value is not large enough, it will just be slower); and by
	29	strtof/strtod/strtold, where it is critical (it's used for overflow
	30	detection).
	31
	32	XXX These should be defined in <float.h>. For the time being, we have the
	33	IEEE754 values here. */
	34
5ce98c3f	35	#if !defined __NO_LONG_DOUBLE_MATH && __LDBL_MAX_EXP__ > 1024
390955cb UD	36	# define LDBL_MAX_10_EXP_LOG 12 /* = floor(log_2(LDBL_MAX_10_EXP)) */
	37	#else
	38	# define LDBL_MAX_10_EXP_LOG 8 /* = floor(log_2(LDBL_MAX_10_EXP)) */
	39	#endif
28f540f4 RM	40	#define DBL_MAX_10_EXP_LOG 8 /* = floor(log_2(DBL_MAX_10_EXP)) */
	41	#define FLT_MAX_10_EXP_LOG 5 /* = floor(log_2(FLT_MAX_10_EXP)) */
	42
82c19bdf PM	43	/* On some machines, _Float128 may be ABI-distinct from long double (e.g
	44	IBM extended precision). */
	45	#include <bits/floatn.h>
	46
cf2046ec GG	47	#if __HAVE_DISTINCT_FLOAT128
	48	# define FLT128_MAX_10_EXP_LOG 12 /* = floor(log_2(FLT128_MAX_10_EXP)) */
	49	#endif
	50
af92131a	51	/* For strtold, we need powers of 10 up to floor (log_2 (LDBL_MANT_DIG
82c19bdf PM	52	- LDBL_MIN_EXP + 2)). When _Float128 is enabled in libm and it is
	53	ABI-distinct from long double (e.g. on powerpc64le), we also need powers
	54	of 10 up to floor (log_2 (FLT128_MANT_DIG - FLT128_MIN_EXP + 2)). */
6c4ee1ab AZ	55	#if (!defined __NO_LONG_DOUBLE_MATH && __LDBL_MAX_EXP__ > 1024) \
	56	\|\| __HAVE_DISTINCT_FLOAT128
	57	# define FPIOCONST_HAVE_EXTENDED_RANGE 1
	58	#else
	59	# define FPIOCONST_HAVE_EXTENDED_RANGE 0
	60	#endif
82c19bdf PM	61
82c19bdf PM	62	#if FPIOCONST_HAVE_EXTENDED_RANGE
af92131a JM	63	# define FPIOCONST_POW10_ARRAY_SIZE 15
	64	#else
	65	# define FPIOCONST_POW10_ARRAY_SIZE 11
	66	#endif
28f540f4	67
c4563d2d	68	/* The array with the number representation. */
418f1701	69	extern const mp_limb_t __tens[] attribute_hidden;
c4563d2d	70
28f540f4 RM	71	/* Table of powers of ten. This is used by __printf_fp and by
	72	strtof/strtod/strtold. */
	73	struct mp_power
	74	{
c4563d2d	75	size_t arrayoff; /* Offset in `__tens'. */
28f540f4 RM	76	mp_size_t arraysize; /* Size of the array. */
	77	int p_expo; /* Exponent of the number 10^(2^i). */
	78	int m_expo; /* Exponent of the number 10^-(2^i-1). */
	79	};
af92131a	80	extern const struct mp_power _fpioconst_pow10[FPIOCONST_POW10_ARRAY_SIZE]
418f1701	81	attribute_hidden;
28f540f4	82
bfc04a9f RM	83	/* The constants in the array `_fpioconst_pow10' have an offset. */
	84	#if BITS_PER_MP_LIMB == 32
	85	# define _FPIO_CONST_OFFSET 2
	86	#else
	87	# define _FPIO_CONST_OFFSET 1
	88	#endif
	89
28f540f4 RM	90
28f540f4 RM	91	#endif /* fpioconst.h */