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, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #ifndef _FPIOCONST_H
  22 #define _FPIOCONST_H
  23
  24 #include <float.h>
  25 #include <math.h>
  26 #include <gmp.h>
  27
  28
  29 /* These values are used by __printf_fp, where they are noncritical (if the
  30    value is not large enough, it will just be slower); and by
  31    strtof/strtod/strtold, where it is critical (it's used for overflow
  32    detection).
  33
  34    XXX These should be defined in <float.h>.  For the time being, we have the
  35    IEEE754 values here.  */
  36
  37 #if !defined __NO_LONG_DOUBLE_MATH && __LDBL_MAX_EXP__ > 1024
  38 # define LDBL_MAX_10_EXP_LOG    12 /* = floor(log_2(LDBL_MAX_10_EXP)) */
  39 #else
  40 # define LDBL_MAX_10_EXP_LOG    8 /* = floor(log_2(LDBL_MAX_10_EXP)) */
  41 #endif
  42 #define DBL_MAX_10_EXP_LOG      8 /* = floor(log_2(DBL_MAX_10_EXP)) */
  43 #define FLT_MAX_10_EXP_LOG      5 /* = floor(log_2(FLT_MAX_10_EXP)) */
  44
  45
  46 /* The array with the number representation. */
  47 extern const mp_limb_t __tens[] attribute_hidden;
  48
  49 /* Table of powers of ten.  This is used by __printf_fp and by
  50    strtof/strtod/strtold.  */
  51 struct mp_power
  52   {
  53     size_t arrayoff;            /* Offset in `__tens'.  */
  54     mp_size_t arraysize;        /* Size of the array.  */
  55     int p_expo;                 /* Exponent of the number 10^(2^i).  */
  56     int m_expo;                 /* Exponent of the number 10^-(2^i-1).  */
  57   };
  58 extern const struct mp_power _fpioconst_pow10[LDBL_MAX_10_EXP_LOG + 1]
  59      attribute_hidden;
  60
  61 /* The constants in the array `_fpioconst_pow10' have an offset.  */
  62 #if BITS_PER_MP_LIMB == 32
  63 # define _FPIO_CONST_OFFSET     2
  64 #else
  65 # define _FPIO_CONST_OFFSET     1
  66 #endif
  67
  68
  69 #endif  /* fpioconst.h */