stdlib/fpioconst.h

   1 /* Header file for constants used in floating point <-> decimal conversions.
   2    Copyright (C) 1995, 1996, 1997, 1998, 1999, 2002, 2003
   3    Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef _FPIOCONST_H
  21 #define _FPIOCONST_H
  22
  23 #include <float.h>
  24 #include <math.h>
  25 #include <gmp.h>
  26
  27
  28 /* These values are used by __printf_fp, where they are noncritical (if the
  29    value is not large enough, it will just be slower); and by
  30    strtof/strtod/strtold, where it is critical (it's used for overflow
  31    detection).
  32
  33    XXX These should be defined in <float.h>.  For the time being, we have the
  34    IEEE754 values here.  */
  35
  36 #if !defined __NO_LONG_DOUBLE_MATH && __LDBL_MAX_EXP__ > 1024
  37 # define LDBL_MAX_10_EXP_LOG    12 /* = floor(log_2(LDBL_MAX_10_EXP)) */
  38 #else
  39 # define LDBL_MAX_10_EXP_LOG    8 /* = floor(log_2(LDBL_MAX_10_EXP)) */
  40 #endif
  41 #define DBL_MAX_10_EXP_LOG      8 /* = floor(log_2(DBL_MAX_10_EXP)) */
  42 #define FLT_MAX_10_EXP_LOG      5 /* = floor(log_2(FLT_MAX_10_EXP)) */
  43
  44
  45 /* The array with the number representation. */
  46 extern const mp_limb_t __tens[] attribute_hidden;
  47
  48 /* Table of powers of ten.  This is used by __printf_fp and by
  49    strtof/strtod/strtold.  */
  50 struct mp_power
  51   {
  52     size_t arrayoff;            /* Offset in `__tens'.  */
  53     mp_size_t arraysize;        /* Size of the array.  */
  54     int p_expo;                 /* Exponent of the number 10^(2^i).  */
  55     int m_expo;                 /* Exponent of the number 10^-(2^i-1).  */
  56   };
  57 extern const struct mp_power _fpioconst_pow10[LDBL_MAX_10_EXP_LOG + 1]
  58      attribute_hidden;
  59
  60 /* The constants in the array `_fpioconst_pow10' have an offset.  */
  61 #if BITS_PER_MP_LIMB == 32
  62 # define _FPIO_CONST_OFFSET     2
  63 #else
  64 # define _FPIO_CONST_OFFSET     1
  65 #endif
  66
  67
  68 #endif  /* fpioconst.h */