1/* Compatibility functions for floating point formatting.
2 Copyright (C) 1995-2019 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 <math.h>
20#include <stdio.h>
21#include <stdlib.h>
22#include <sys/param.h>
23#include <float.h>
24#include <libc-lock.h>
25#include <math_ldbl_opt.h>
26
27#ifndef FLOAT_TYPE
28# define FLOAT_TYPE double
29# define FUNC_PREFIX
30# define FLOAT_FMT_FLAG
31/* Actually we have to write (DBL_DIG + log10 (DBL_MAX_10_EXP)) but we
32 don't have log10 available in the preprocessor. */
33# define MAXDIG (NDIGIT_MAX + 3)
34# define FCVT_MAXDIG (DBL_MAX_10_EXP + MAXDIG)
35# if DBL_MANT_DIG == 53
36# define NDIGIT_MAX 17
37# elif DBL_MANT_DIG == 24
38# define NDIGIT_MAX 9
39# elif DBL_MANT_DIG == 56
40# define NDIGIT_MAX 18
41# else
42/* See IEEE 854 5.6, table 2 for this formula. Unfortunately we need a
43 compile time constant here, so we cannot use it. */
44# error "NDIGIT_MAX must be precomputed"
45# define NDIGIT_MAX (lrint (ceil (M_LN2 / M_LN10 * DBL_MANT_DIG + 1.0)))
46# endif
47#else
48# define LONG_DOUBLE_CVT
49#endif
50
51#define APPEND(a, b) APPEND2 (a, b)
52#define APPEND2(a, b) a##b
53#define __APPEND(a, b) __APPEND2 (a, b)
54#define __APPEND2(a, b) __##a##b
55
56
57#define FCVT_BUFFER APPEND (FUNC_PREFIX, fcvt_buffer)
58#define FCVT_BUFPTR APPEND (FUNC_PREFIX, fcvt_bufptr)
59#define ECVT_BUFFER APPEND (FUNC_PREFIX, ecvt_buffer)
60
61
62static char FCVT_BUFFER[MAXDIG];
63static char ECVT_BUFFER[MAXDIG];
64libc_freeres_ptr (static char *FCVT_BUFPTR);
65
66char *
67__APPEND (FUNC_PREFIX, fcvt) (FLOAT_TYPE value, int ndigit, int *decpt,
68 int *sign)
69{
70 if (FCVT_BUFPTR == NULL)
71 {
72 if (__APPEND (FUNC_PREFIX, fcvt_r) (value, ndigit, decpt, sign,
73 FCVT_BUFFER, MAXDIG) != -1)
74 return FCVT_BUFFER;
75
76 FCVT_BUFPTR = (char *) malloc (FCVT_MAXDIG);
77 if (FCVT_BUFPTR == NULL)
78 return FCVT_BUFFER;
79 }
80
81 (void) __APPEND (FUNC_PREFIX, fcvt_r) (value, ndigit, decpt, sign,
82 FCVT_BUFPTR, FCVT_MAXDIG);
83
84 return FCVT_BUFPTR;
85}
86
87
88char *
89__APPEND (FUNC_PREFIX, ecvt) (FLOAT_TYPE value, int ndigit, int *decpt,
90 int *sign)
91{
92 (void) __APPEND (FUNC_PREFIX, ecvt_r) (value, ndigit, decpt, sign,
93 ECVT_BUFFER, MAXDIG);
94
95 return ECVT_BUFFER;
96}
97
98char *
99__APPEND (FUNC_PREFIX, gcvt) (FLOAT_TYPE value, int ndigit, char *buf)
100{
101 sprintf (buf, "%.*" FLOAT_FMT_FLAG "g", MIN (ndigit, NDIGIT_MAX), value);
102 return buf;
103}
104
105#if LONG_DOUBLE_COMPAT (libc, GLIBC_2_0)
106# ifdef LONG_DOUBLE_CVT
107# define cvt_symbol(symbol) \
108 cvt_symbol_1 (libc, __APPEND (FUNC_PREFIX, symbol), \
109 APPEND (FUNC_PREFIX, symbol), GLIBC_2_4)
110# define cvt_symbol_1(lib, local, symbol, version) \
111 versioned_symbol (lib, local, symbol, version)
112# else
113# define cvt_symbol(symbol) \
114 cvt_symbol_1 (libc, __APPEND (FUNC_PREFIX, symbol), \
115 APPEND (q, symbol), GLIBC_2_0); \
116 strong_alias (__APPEND (FUNC_PREFIX, symbol), APPEND (FUNC_PREFIX, symbol))
117# define cvt_symbol_1(lib, local, symbol, version) \
118 compat_symbol (lib, local, symbol, version)
119# endif
120#else
121# define cvt_symbol(symbol) \
122 strong_alias (__APPEND (FUNC_PREFIX, symbol), APPEND (FUNC_PREFIX, symbol))
123#endif
124cvt_symbol(fcvt);
125cvt_symbol(ecvt);
126cvt_symbol(gcvt);
127