mirror of
git://sourceware.org/git/glibc.git
synced 2024-12-03 04:01:43 +08:00
1d446ec644
* misc/efgcvt_r.c: Likewise.
266 lines
6.1 KiB
C
266 lines
6.1 KiB
C
/* Compatibility functions for floating point formatting, reentrant versions.
|
|
Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2004, 2006
|
|
Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
#include <errno.h>
|
|
#include <float.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <ctype.h>
|
|
#include <math.h>
|
|
#include <stdlib.h>
|
|
#include <sys/param.h>
|
|
#include <math_ldbl_opt.h>
|
|
|
|
#ifndef FLOAT_TYPE
|
|
# define FLOAT_TYPE double
|
|
# define FUNC_PREFIX
|
|
# define FLOAT_FMT_FLAG
|
|
# define FLOAT_NAME_EXT
|
|
# define FLOAT_MIN_10_EXP DBL_MIN_10_EXP
|
|
# if DBL_MANT_DIG == 53
|
|
# define NDIGIT_MAX 17
|
|
# elif DBL_MANT_DIG == 24
|
|
# define NDIGIT_MAX 9
|
|
# elif DBL_MANT_DIG == 56
|
|
# define NDIGIT_MAX 18
|
|
# else
|
|
/* See IEEE 854 5.6, table 2 for this formula. Unfortunately we need a
|
|
compile time constant here, so we cannot use it. */
|
|
# error "NDIGIT_MAX must be precomputed"
|
|
# define NDIGIT_MAX (lrint (ceil (M_LN2 / M_LN10 * DBL_MANT_DIG + 1.0)))
|
|
# endif
|
|
# if DBL_MIN_10_EXP == -37
|
|
# define FLOAT_MIN_10_NORM 1.0e-37
|
|
# elif DBL_MIN_10_EXP == -307
|
|
# define FLOAT_MIN_10_NORM 1.0e-307
|
|
# elif DBL_MIN_10_EXP == -4931
|
|
# define FLOAT_MIN_10_NORM 1.0e-4931
|
|
# else
|
|
/* libc can't depend on libm. */
|
|
# error "FLOAT_MIN_10_NORM must be precomputed"
|
|
# define FLOAT_MIN_10_NORM exp10 (DBL_MIN_10_EXP)
|
|
# endif
|
|
#else
|
|
# define LONG_DOUBLE_CVT
|
|
#endif
|
|
|
|
#define APPEND(a, b) APPEND2 (a, b)
|
|
#define APPEND2(a, b) a##b
|
|
#define __APPEND(a, b) __APPEND2 (a, b)
|
|
#define __APPEND2(a, b) __##a##b
|
|
|
|
#define FLOOR APPEND(floor, FLOAT_NAME_EXT)
|
|
#define FABS APPEND(fabs, FLOAT_NAME_EXT)
|
|
#define LOG10 APPEND(log10, FLOAT_NAME_EXT)
|
|
#define EXP APPEND(exp, FLOAT_NAME_EXT)
|
|
|
|
|
|
int
|
|
__APPEND (FUNC_PREFIX, fcvt_r) (value, ndigit, decpt, sign, buf, len)
|
|
FLOAT_TYPE value;
|
|
int ndigit, *decpt, *sign;
|
|
char *buf;
|
|
size_t len;
|
|
{
|
|
ssize_t n;
|
|
ssize_t i;
|
|
int left;
|
|
|
|
if (buf == NULL)
|
|
{
|
|
__set_errno (EINVAL);
|
|
return -1;
|
|
}
|
|
|
|
left = 0;
|
|
if (isfinite (value))
|
|
{
|
|
*sign = signbit (value) != 0;
|
|
if (*sign)
|
|
value = -value;
|
|
|
|
if (ndigit < 0)
|
|
{
|
|
/* Rounding to the left of the decimal point. */
|
|
while (ndigit < 0)
|
|
{
|
|
FLOAT_TYPE new_value = value * 0.1;
|
|
|
|
if (new_value < 1.0)
|
|
{
|
|
ndigit = 0;
|
|
break;
|
|
}
|
|
|
|
value = new_value;
|
|
++left;
|
|
++ndigit;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
/* Value is Inf or NaN. */
|
|
*sign = 0;
|
|
|
|
n = __snprintf (buf, len, "%.*" FLOAT_FMT_FLAG "f", MIN (ndigit, NDIGIT_MAX),
|
|
value);
|
|
/* Check for a too small buffer. */
|
|
if (n >= (ssize_t) len)
|
|
return -1;
|
|
|
|
i = 0;
|
|
while (i < n && isdigit (buf[i]))
|
|
++i;
|
|
*decpt = i;
|
|
|
|
if (i == 0)
|
|
/* Value is Inf or NaN. */
|
|
return 0;
|
|
|
|
if (i < n)
|
|
{
|
|
do
|
|
++i;
|
|
while (i < n && !isdigit (buf[i]));
|
|
|
|
if (*decpt == 1 && buf[0] == '0' && value != 0.0)
|
|
{
|
|
/* We must not have leading zeroes. Strip them all out and
|
|
adjust *DECPT if necessary. */
|
|
--*decpt;
|
|
while (i < n && buf[i] == '0')
|
|
{
|
|
--*decpt;
|
|
++i;
|
|
}
|
|
}
|
|
|
|
memmove (&buf[MAX (*decpt, 0)], &buf[i], n - i);
|
|
buf[n - (i - MAX (*decpt, 0))] = '\0';
|
|
}
|
|
|
|
if (left)
|
|
{
|
|
*decpt += left;
|
|
if ((ssize_t) --len > n)
|
|
{
|
|
while (left-- > 0 && n < (ssize_t) len)
|
|
buf[n++] = '0';
|
|
buf[n] = '\0';
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
__APPEND (FUNC_PREFIX, ecvt_r) (value, ndigit, decpt, sign, buf, len)
|
|
FLOAT_TYPE value;
|
|
int ndigit, *decpt, *sign;
|
|
char *buf;
|
|
size_t len;
|
|
{
|
|
int exponent = 0;
|
|
|
|
if (isfinite (value) && value != 0.0)
|
|
{
|
|
/* Slow code that doesn't require -lm functions. */
|
|
FLOAT_TYPE d;
|
|
FLOAT_TYPE f = 1.0;
|
|
if (value < 0.0)
|
|
d = -value;
|
|
else
|
|
d = value;
|
|
/* For denormalized numbers the d < 1.0 case below won't work,
|
|
as f can overflow to +Inf. */
|
|
if (d < FLOAT_MIN_10_NORM)
|
|
{
|
|
value /= FLOAT_MIN_10_NORM;
|
|
if (value < 0.0)
|
|
d = -value;
|
|
else
|
|
d = value;
|
|
exponent += FLOAT_MIN_10_EXP;
|
|
}
|
|
if (d < 1.0)
|
|
{
|
|
do
|
|
{
|
|
f *= 10.0;
|
|
--exponent;
|
|
}
|
|
while (d * f < 1.0);
|
|
|
|
value *= f;
|
|
}
|
|
else if (d >= 10.0)
|
|
{
|
|
do
|
|
{
|
|
f *= 10;
|
|
++exponent;
|
|
}
|
|
while (d >= f * 10.0);
|
|
|
|
value /= f;
|
|
}
|
|
}
|
|
else if (value == 0.0)
|
|
/* SUSv2 leaves it unspecified whether *DECPT is 0 or 1 for 0.0.
|
|
This could be changed to -1 if we want to return 0. */
|
|
exponent = 0;
|
|
|
|
if (ndigit <= 0 && len > 0)
|
|
{
|
|
buf[0] = '\0';
|
|
*decpt = 1;
|
|
*sign = isfinite (value) ? signbit (value) != 0 : 0;
|
|
}
|
|
else
|
|
if (__APPEND (FUNC_PREFIX, fcvt_r) (value, MIN (ndigit, NDIGIT_MAX) - 1,
|
|
decpt, sign, buf, len))
|
|
return -1;
|
|
|
|
*decpt += exponent;
|
|
return 0;
|
|
}
|
|
|
|
#if LONG_DOUBLE_COMPAT (libc, GLIBC_2_0)
|
|
# ifdef LONG_DOUBLE_CVT
|
|
# define cvt_symbol(symbol) \
|
|
cvt_symbol_1 (libc, __APPEND (FUNC_PREFIX, symbol), \
|
|
APPEND (FUNC_PREFIX, symbol), GLIBC_2_4)
|
|
# define cvt_symbol_1(lib, local, symbol, version) \
|
|
versioned_symbol (lib, local, symbol, version)
|
|
# else
|
|
# define cvt_symbol(symbol) \
|
|
cvt_symbol_1 (libc, __APPEND (FUNC_PREFIX, symbol), \
|
|
APPEND (q, symbol), GLIBC_2_0); \
|
|
strong_alias (__APPEND (FUNC_PREFIX, symbol), APPEND (FUNC_PREFIX, symbol))
|
|
# define cvt_symbol_1(lib, local, symbol, version) \
|
|
compat_symbol (lib, local, symbol, version)
|
|
# endif
|
|
#else
|
|
# define cvt_symbol(symbol) \
|
|
strong_alias (__APPEND (FUNC_PREFIX, symbol), APPEND (FUNC_PREFIX, symbol))
|
|
#endif
|
|
cvt_symbol(fcvt_r);
|
|
cvt_symbol(ecvt_r);
|