1 /* Compatibility functions for floating point formatting, long double version.
2 Copyright (C) 1996, 1997, 1999, 2000 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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.
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.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
22 #define FLOAT_TYPE long double
24 #define FLOAT_FMT_FLAG "L"
25 /* Actually we have to write (LDBL_DIG + log10 (LDBL_MAX_10_EXP)) but
26 we don't have log10 available in the preprocessor. Since we cannot
27 assume anything on the used `long double' format be generous. */
28 #define MAXDIG (NDIGIT_MAX + 12)
29 #define FCVT_MAXDIG (LDBL_MAX_10_EXP + MAXDIG)
30 #if LDBL_MANT_DIG == 64
31 # define NDIGIT_MAX 21
32 #elif LDBL_MANT_DIG == 53
33 # define NDIGIT_MAX 17
34 #elif LDBL_MANT_DIG == 113
35 # define NDIGIT_MAX 36
36 #elif LDBL_MANT_DIG == 106
37 # define NDIGIT_MAX 34
38 #elif LDBL_MANT_DIG == 56
39 # define NDIGIT_MAX 18
41 /* See IEEE 854 5.6, table 2 for this formula. Unfortunately we need a
42 compile time constant here, so we cannot use it. */
43 # error "NDIGIT_MAX must be precomputed"
44 # define NDIGIT_MAX (lrint (ceil (M_LN2 / M_LN10 * LDBL_MANT_DIG + 1.0)))