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, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <math.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <sys/param.h>
  24 #include <float.h>
  25 #include <bits/libc-lock.h>
  26 #include <math_ldbl_opt.h>
  27
  28 #ifndef FLOAT_TYPE
  29 # define FLOAT_TYPE double
  30 # define FUNC_PREFIX
  31 # define FLOAT_FMT_FLAG
  32 /* Actually we have to write (DBL_DIG + log10 (DBL_MAX_10_EXP)) but we
  33    don't have log10 available in the preprocessor.  */
  34 # define MAXDIG (NDIGIT_MAX + 3)
  35 # define FCVT_MAXDIG (DBL_MAX_10_EXP + MAXDIG)
  36 # if DBL_MANT_DIG == 53
  37 #  define NDIGIT_MAX 17
  38 # elif DBL_MANT_DIG == 24
  39 #  define NDIGIT_MAX 9
  40 # elif DBL_MANT_DIG == 56
  41 #  define NDIGIT_MAX 18
  42 # else
  43 /* See IEEE 854 5.6, table 2 for this formula.  Unfortunately we need a
  44    compile time constant here, so we cannot use it.  */
  45 #  error "NDIGIT_MAX must be precomputed"
  46 #  define NDIGIT_MAX (lrint (ceil (M_LN2 / M_LN10 * DBL_MANT_DIG + 1.0)))
  47 # endif
  48 #else
  49 # define LONG_DOUBLE_CVT
  50 #endif
  51
  52 #define APPEND(a, b) APPEND2 (a, b)
  53 #define APPEND2(a, b) a##b
  54 #define __APPEND(a, b) __APPEND2 (a, b)
  55 #define __APPEND2(a, b) __##a##b
  56
  57
  58 #define FCVT_BUFFER APPEND (FUNC_PREFIX, fcvt_buffer)
  59 #define FCVT_BUFPTR APPEND (FUNC_PREFIX, fcvt_bufptr)
  60 #define ECVT_BUFFER APPEND (FUNC_PREFIX, ecvt_buffer)
  61
  62
  63 static char FCVT_BUFFER[MAXDIG];
  64 static char ECVT_BUFFER[MAXDIG];
  65 libc_freeres_ptr (static char *FCVT_BUFPTR);
  66
  67 char *
  68 __APPEND (FUNC_PREFIX, fcvt) (value, ndigit, decpt, sign)
  69      FLOAT_TYPE value;
  70      int ndigit, *decpt, *sign;
  71 {
  72   if (FCVT_BUFPTR == NULL)
  73     {
  74       if (__APPEND (FUNC_PREFIX, fcvt_r) (value, ndigit, decpt, sign,
  75                                           FCVT_BUFFER, MAXDIG) != -1)
  76         return FCVT_BUFFER;
  77
  78       FCVT_BUFPTR = (char *) malloc (FCVT_MAXDIG);
  79       if (FCVT_BUFPTR == NULL)
  80         return FCVT_BUFFER;
  81     }
  82
  83   (void) __APPEND (FUNC_PREFIX, fcvt_r) (value, ndigit, decpt, sign,
  84                                          FCVT_BUFPTR, FCVT_MAXDIG);
  85
  86   return FCVT_BUFPTR;
  87 }
  88
  89
  90 char *
  91 __APPEND (FUNC_PREFIX, ecvt) (value, ndigit, decpt, sign)
  92      FLOAT_TYPE value;
  93      int ndigit, *decpt, *sign;
  94 {
  95   (void) __APPEND (FUNC_PREFIX, ecvt_r) (value, ndigit, decpt, sign,
  96                                          ECVT_BUFFER, MAXDIG);
  97
  98   return ECVT_BUFFER;
  99 }
 100
 101 char *
 102 __APPEND (FUNC_PREFIX, gcvt) (value, ndigit, buf)
 103      FLOAT_TYPE value;
 104      int ndigit;
 105      char *buf;
 106 {
 107   sprintf (buf, "%.*" FLOAT_FMT_FLAG "g", MIN (ndigit, NDIGIT_MAX), value);
 108   return buf;
 109 }
 110
 111 #if LONG_DOUBLE_COMPAT (libc, GLIBC_2_0)
 112 # ifdef LONG_DOUBLE_CVT
 113 #  define cvt_symbol(symbol) \
 114   cvt_symbol_1 (libc, __APPEND (FUNC_PREFIX, symbol), \
 115               APPEND (FUNC_PREFIX, symbol), GLIBC_2_4)
 116 #  define cvt_symbol_1(lib, local, symbol, version) \
 117     versioned_symbol (lib, local, symbol, version)
 118 # else
 119 #  define cvt_symbol(symbol) \
 120   cvt_symbol_1 (libc, __APPEND (FUNC_PREFIX, symbol), \
 121               APPEND (q, symbol), GLIBC_2_0); \
 122   strong_alias (__APPEND (FUNC_PREFIX, symbol), APPEND (FUNC_PREFIX, symbol))
 123 #  define cvt_symbol_1(lib, local, symbol, version) \
 124   compat_symbol (lib, local, symbol, version)
 125 # endif
 126 #else
 127 # define cvt_symbol(symbol) \
 128   strong_alias (__APPEND (FUNC_PREFIX, symbol), APPEND (FUNC_PREFIX, symbol))
 129 #endif
 130 cvt_symbol(fcvt);
 131 cvt_symbol(ecvt);
 132 cvt_symbol(gcvt);