1/* Macros for the implementation of *cvt functions, long double version.
2 Copyright (C) 1996-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
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.
9
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
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <float.h>
20
21#define FLOAT_TYPE long double
22#define FUNC_PREFIX q
23#define FLOAT_FMT_FLAG "L"
24#define FLOAT_NAME_EXT l
25#define FLOAT_MIN_10_EXP LDBL_MIN_10_EXP
26/* Actually we have to write (LDBL_DIG + log10 (LDBL_MAX_10_EXP)) but
27 we don't have log10 available in the preprocessor. Since we cannot
28 assume anything on the used `long double' format be generous. */
29#define MAXDIG (NDIGIT_MAX + 12)
30#define FCVT_MAXDIG (LDBL_MAX_10_EXP + MAXDIG)
31#if LDBL_MANT_DIG == 64
32# define NDIGIT_MAX 21
33#elif LDBL_MANT_DIG == 53
34# define NDIGIT_MAX 17
35#elif LDBL_MANT_DIG == 113
36# define NDIGIT_MAX 36
37#elif LDBL_MANT_DIG == 106
38# define NDIGIT_MAX 34
39#elif LDBL_MANT_DIG == 56
40# define NDIGIT_MAX 18
41#else
42/* See IEEE 854 5.6, table 2 for this formula. Unfortunately we need a
43 compile time constant here, so we cannot use it. */
44# error "NDIGIT_MAX must be precomputed"
45# define NDIGIT_MAX (lrint (ceil (M_LN2 / M_LN10 * LDBL_MANT_DIG + 1.0)))
46#endif
47#if LDBL_MIN_10_EXP == -37
48# define FLOAT_MIN_10_NORM 1.0e-37L
49#elif LDBL_MIN_10_EXP == -291
50# define FLOAT_MIN_10_NORM 1.0e-291L
51#elif LDBL_MIN_10_EXP == -307
52# define FLOAT_MIN_10_NORM 1.0e-307L
53#elif LDBL_MIN_10_EXP == -4931
54# define FLOAT_MIN_10_NORM 1.0e-4931L
55#else
56/* libc can't depend on libm. */
57# error "FLOAT_MIN_10_NORM must be precomputed"
58# define FLOAT_MIN_10_NORM exp10l (LDBL_MIN_10_EXP)
59#endif
60