1/* Macros for the implementation of *cvt functions, double version.
2 Copyright (C) 1995-2020 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 double
22#define FUNC_PREFIX
23#define FLOAT_FMT_FLAG
24#define FLOAT_NAME_EXT
25#define FLOAT_MIN_10_EXP DBL_MIN_10_EXP
26/* Actually we have to write (DBL_DIG + log10 (DBL_MAX_10_EXP)) but we
27 don't have log10 available in the preprocessor. */
28#define MAXDIG (NDIGIT_MAX + 3)
29#define FCVT_MAXDIG (DBL_MAX_10_EXP + MAXDIG)
30#if DBL_MANT_DIG == 53
31# define NDIGIT_MAX 17
32#elif DBL_MANT_DIG == 24
33# define NDIGIT_MAX 9
34#elif DBL_MANT_DIG == 56
35# define NDIGIT_MAX 18
36#else
37/* See IEEE 854 5.6, table 2 for this formula. Unfortunately we need a
38 compile time constant here, so we cannot use it. */
39# error "NDIGIT_MAX must be precomputed"
40# define NDIGIT_MAX (lrint (ceil (M_LN2 / M_LN10 * DBL_MANT_DIG + 1.0)))
41#endif
42#if DBL_MIN_10_EXP == -37
43# define FLOAT_MIN_10_NORM 1.0e-37
44#elif DBL_MIN_10_EXP == -307
45# define FLOAT_MIN_10_NORM 1.0e-307
46#elif DBL_MIN_10_EXP == -4931
47# define FLOAT_MIN_10_NORM 1.0e-4931
48#else
49/* libc can't depend on libm. */
50# error "FLOAT_MIN_10_NORM must be precomputed"
51# define FLOAT_MIN_10_NORM exp10 (DBL_MIN_10_EXP)
52#endif
53