misc/qefgcvt.c

   1 /* Compatibility functions for floating point formatting, long double version.
   2    Copyright (C) 1996-2013 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    <http://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 /* Actually we have to write (LDBL_DIG + log10 (LDBL_MAX_10_EXP)) but
  25    we don't have log10 available in the preprocessor.  Since we cannot
  26    assume anything on the used `long double' format be generous.  */
  27 #define MAXDIG (NDIGIT_MAX + 12)
  28 #define FCVT_MAXDIG (LDBL_MAX_10_EXP + MAXDIG)
  29 #if LDBL_MANT_DIG == 64
  30 # define NDIGIT_MAX 21
  31 #elif LDBL_MANT_DIG == 53
  32 # define NDIGIT_MAX 17
  33 #elif LDBL_MANT_DIG == 113
  34 # define NDIGIT_MAX 36
  35 #elif LDBL_MANT_DIG == 106
  36 # define NDIGIT_MAX 34
  37 #elif LDBL_MANT_DIG == 56
  38 # define NDIGIT_MAX 18
  39 #else
  40 /* See IEEE 854 5.6, table 2 for this formula.  Unfortunately we need a
  41    compile time constant here, so we cannot use it.  */
  42 # error "NDIGIT_MAX must be precomputed"
  43 # define NDIGIT_MAX (lrint (ceil (M_LN2 / M_LN10 * LDBL_MANT_DIG + 1.0)))
  44 #endif
  45
  46 #include "efgcvt.c"