misc/efgcvt.c

   1 /* Compatibility functions for floating point formatting.
   2    Copyright (C) 1995, 1996, 1997, 1999, 2002, 2006
   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 #include <math.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <sys/param.h>
  25 #include <float.h>
  26 #include <bits/libc-lock.h>
  27 #include <math_ldbl_opt.h>
  28
  29 #ifndef FLOAT_TYPE
  30 # define FLOAT_TYPE double
  31 # define FUNC_PREFIX
  32 # define FLOAT_FMT_FLAG
  33 /* Actually we have to write (DBL_DIG + log10 (DBL_MAX_10_EXP)) but we
  34    don't have log10 available in the preprocessor.  */
  35 # define MAXDIG (NDIGIT_MAX + 3)
  36 # define FCVT_MAXDIG (DBL_MAX_10_EXP + MAXDIG)
  37 # if DBL_MANT_DIG == 53
  38 #  define NDIGIT_MAX 17
  39 # elif DBL_MANT_DIG == 24
  40 #  define NDIGIT_MAX 9
  41 # elif DBL_MANT_DIG == 56
  42 #  define NDIGIT_MAX 18
  43 # else
  44 /* See IEEE 854 5.6, table 2 for this formula.  Unfortunately we need a
  45    compile time constant here, so we cannot use it.  */
  46 #  error "NDIGIT_MAX must be precomputed"
  47 #  define NDIGIT_MAX (lrint (ceil (M_LN2 / M_LN10 * DBL_MANT_DIG + 1.0)))
  48 # endif
  49 #else
  50 # define LONG_DOUBLE_CVT
  51 #endif
  52
  53 #define APPEND(a, b) APPEND2 (a, b)
  54 #define APPEND2(a, b) a##b
  55 #define __APPEND(a, b) __APPEND2 (a, b)
  56 #define __APPEND2(a, b) __##a##b
  57
  58
  59 #define FCVT_BUFFER APPEND (FUNC_PREFIX, fcvt_buffer)
  60 #define FCVT_BUFPTR APPEND (FUNC_PREFIX, fcvt_bufptr)
  61 #define ECVT_BUFFER APPEND (FUNC_PREFIX, ecvt_buffer)
  62
  63
  64 static char FCVT_BUFFER[MAXDIG];
  65 static char ECVT_BUFFER[MAXDIG];
  66 libc_freeres_ptr (static char *FCVT_BUFPTR);
  67
  68 char *
  69 __APPEND (FUNC_PREFIX, fcvt) (value, ndigit, decpt, sign)
  70      FLOAT_TYPE value;
  71      int ndigit, *decpt, *sign;
  72 {
  73   if (FCVT_BUFPTR == NULL)
  74     {
  75       if (__APPEND (FUNC_PREFIX, fcvt_r) (value, ndigit, decpt, sign,
  76                                           FCVT_BUFFER, MAXDIG) != -1)
  77         return FCVT_BUFFER;
  78
  79       FCVT_BUFPTR = (char *) malloc (FCVT_MAXDIG);
  80       if (FCVT_BUFPTR == NULL)
  81         return FCVT_BUFFER;
  82     }
  83
  84   (void) __APPEND (FUNC_PREFIX, fcvt_r) (value, ndigit, decpt, sign,
  85                                          FCVT_BUFPTR, FCVT_MAXDIG);
  86
  87   return FCVT_BUFPTR;
  88 }
  89
  90
  91 char *
  92 __APPEND (FUNC_PREFIX, ecvt) (value, ndigit, decpt, sign)
  93      FLOAT_TYPE value;
  94      int ndigit, *decpt, *sign;
  95 {
  96   (void) __APPEND (FUNC_PREFIX, ecvt_r) (value, ndigit, decpt, sign,
  97                                          ECVT_BUFFER, MAXDIG);
  98
  99   return ECVT_BUFFER;
 100 }
 101
 102 char *
 103 __APPEND (FUNC_PREFIX, gcvt) (value, ndigit, buf)
 104      FLOAT_TYPE value;
 105      int ndigit;
 106      char *buf;
 107 {
 108   sprintf (buf, "%.*" FLOAT_FMT_FLAG "g", MIN (ndigit, NDIGIT_MAX), value);
 109   return buf;
 110 }
 111
 112 #if LONG_DOUBLE_COMPAT (libc, GLIBC_2_0)
 113 # ifdef LONG_DOUBLE_CVT
 114 #  define cvt_symbol(symbol) \
 115   cvt_symbol_1 (libc, __APPEND (FUNC_PREFIX, symbol), \
 116               APPEND (FUNC_PREFIX, symbol), GLIBC_2_4)
 117 #  define cvt_symbol_1(lib, local, symbol, version) \
 118     versioned_symbol (lib, local, symbol, version)
 119 # else
 120 #  define cvt_symbol(symbol) \
 121   cvt_symbol_1 (libc, __APPEND (FUNC_PREFIX, symbol), \
 122               APPEND (q, symbol), GLIBC_2_0); \
 123   strong_alias (__APPEND (FUNC_PREFIX, symbol), APPEND (FUNC_PREFIX, symbol))
 124 #  define cvt_symbol_1(lib, local, symbol, version) \
 125   compat_symbol (lib, local, symbol, version)
 126 # endif
 127 #else
 128 # define cvt_symbol(symbol) \
 129   strong_alias (__APPEND (FUNC_PREFIX, symbol), APPEND (FUNC_PREFIX, symbol))
 130 #endif
 131 cvt_symbol(fcvt);
 132 cvt_symbol(ecvt);
 133 cvt_symbol(gcvt);