332 lines
9.8 KiB
C
332 lines
9.8 KiB
C
/****************************************************************************
|
|
* libc/unistd/lib_libdtoa.c
|
|
*
|
|
* This file was ported to NuttX by Yolande Cates.
|
|
*
|
|
* Copyright (c) 1990, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to Berkeley by
|
|
* Chris Torek.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <math.h>
|
|
|
|
#include "lib_internal.h"
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
#define MAX_PREC 16
|
|
|
|
#ifndef MIN
|
|
# define MIN(a,b) (a < b ? a : b)
|
|
#endif
|
|
|
|
#ifndef MAX
|
|
# define MAX(a,b) (a > b ? a : b)
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Private Type Declarations
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Function Prototypes
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Global Constant Data
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Global Variables
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Constant Data
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Variables
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: zeroes
|
|
*
|
|
* Description:
|
|
* Print the specified number of zeres
|
|
*
|
|
****************************************************************************/
|
|
|
|
static void zeroes(FAR struct lib_outstream_s *obj, int nzeroes)
|
|
{
|
|
int i;
|
|
|
|
for (i = nzeroes; i > 0; i--)
|
|
{
|
|
obj->put(obj, '0');
|
|
}
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: lib_dtoa_string
|
|
*
|
|
* Description:
|
|
* Print the specified string
|
|
*
|
|
****************************************************************************/
|
|
|
|
static void lib_dtoa_string(FAR struct lib_outstream_s *obj, const char *str)
|
|
{
|
|
while (*str)
|
|
{
|
|
obj->put(obj, *str++);
|
|
}
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: lib_dtoa
|
|
*
|
|
* Description:
|
|
* This is part of lib_vsprintf(). It handles the floating point formats.
|
|
* This version supports only the %f (with precision). If no precision
|
|
* was provided in the format, this will use precision == 0 which is
|
|
* probably not what you want.
|
|
*
|
|
* Input Parameters:
|
|
* obj - The output stream object
|
|
* fmt - The format character. Not used 'f' is always assumed
|
|
* prec - The number of digits to the right of the decimal point. If no
|
|
* precision is provided in the format, this will be zero. And,
|
|
* unfortunately in this case, it will be treated literally as
|
|
* a precision of zero.
|
|
* flags - Only ALTFORM and SHOWPLUS flags are supported. ALTFORM only
|
|
* applies if prec == 0 which is not supported anyway.
|
|
* value - The floating point value to convert.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static void lib_dtoa(FAR struct lib_outstream_s *obj, int fmt, int prec,
|
|
uint8_t flags, double value)
|
|
{
|
|
FAR char *digits; /* String returned by __dtoa */
|
|
FAR char *rve; /* Points to the end of the return value */
|
|
int expt; /* Integer value of exponent */
|
|
int numlen; /* Actual number of digits returned by cvt */
|
|
int nchars; /* Number of characters to print */
|
|
int dsgn; /* Unused sign indicator */
|
|
int i;
|
|
|
|
/* Special handling for NaN and Infinity */
|
|
|
|
if (isnan(value))
|
|
{
|
|
lib_dtoa_string(obj, "NaN");
|
|
return;
|
|
}
|
|
|
|
if (isinf(value))
|
|
{
|
|
if (value < 0.0)
|
|
{
|
|
obj->put(obj, '-');
|
|
}
|
|
|
|
lib_dtoa_string(obj, "Infinity");
|
|
return;
|
|
}
|
|
|
|
/* Non-zero... positive or negative */
|
|
|
|
if (value < 0)
|
|
{
|
|
value = -value;
|
|
SET_NEGATE(flags);
|
|
}
|
|
|
|
/* Perform the conversion */
|
|
|
|
digits = __dtoa(value, 3, prec, &expt, &dsgn, &rve);
|
|
numlen = rve - digits;
|
|
|
|
if (IS_NEGATE(flags))
|
|
{
|
|
obj->put(obj, '-');
|
|
}
|
|
else if (IS_SHOWPLUS(flags))
|
|
{
|
|
obj->put(obj, '+');
|
|
}
|
|
|
|
/* Special case exact zero or the case where the number is smaller than
|
|
* the print precision.
|
|
*/
|
|
|
|
if (value == 0 || expt < -prec)
|
|
{
|
|
/* kludge for __dtoa irregularity */
|
|
|
|
obj->put(obj, '0');
|
|
|
|
/* A decimal point is printed only in the alternate form or if a
|
|
* particular precision is requested.
|
|
*/
|
|
|
|
if (prec > 0 || IS_ALTFORM(flags))
|
|
{
|
|
obj->put(obj, '.');
|
|
|
|
/* Always print at least one digit to the right of the decimal point. */
|
|
|
|
prec = MAX(1, prec);
|
|
}
|
|
}
|
|
|
|
/* A non-zero value will be printed */
|
|
|
|
else
|
|
{
|
|
|
|
/* Handle the case where the value is less than 1.0 (in magnitude) and
|
|
* will need a leading zero.
|
|
*/
|
|
|
|
if (expt <= 0)
|
|
{
|
|
/* Print a single zero to the left of the decimal point */
|
|
|
|
obj->put(obj, '0');
|
|
|
|
/* Print the decimal point */
|
|
|
|
obj->put(obj, '.');
|
|
|
|
/* Print any leading zeros to the right of the decimal point */
|
|
|
|
if (expt < 0)
|
|
{
|
|
nchars = MIN(-expt, prec);
|
|
zeroes(obj, nchars);
|
|
prec -= nchars;
|
|
}
|
|
}
|
|
|
|
/* Handle the general case where the value is greater than 1.0 (in
|
|
* magnitude).
|
|
*/
|
|
|
|
else
|
|
{
|
|
/* Print the integer part to the left of the decimal point */
|
|
|
|
for (i = expt; i > 0; i--)
|
|
{
|
|
if (*digits != '\0')
|
|
{
|
|
obj->put(obj, *digits);
|
|
digits++;
|
|
}
|
|
else
|
|
{
|
|
obj->put(obj, '0');
|
|
}
|
|
}
|
|
|
|
/* Get the length of the fractional part */
|
|
|
|
numlen -= expt;
|
|
|
|
/* If there is no fractional part, then a decimal point is printed
|
|
* only in the alternate form or if a particular precision is
|
|
* requested.
|
|
*/
|
|
|
|
if (numlen > 0 || prec > 0 || IS_ALTFORM(flags))
|
|
{
|
|
/* Print the decimal point */
|
|
|
|
obj->put(obj, '.');
|
|
|
|
/* Always print at least one digit to the right of the decimal
|
|
* point.
|
|
*/
|
|
|
|
prec = MAX(1, prec);
|
|
}
|
|
}
|
|
|
|
/* If a precision was specified, then limit the number digits to the
|
|
* right of the decimal point.
|
|
*/
|
|
|
|
if (prec > 0)
|
|
{
|
|
nchars = MIN(numlen, prec);
|
|
}
|
|
else
|
|
{
|
|
nchars = numlen;
|
|
}
|
|
|
|
/* Print the fractional part to the right of the decimal point */
|
|
|
|
for (i = nchars; i > 0; i--)
|
|
{
|
|
obj->put(obj, *digits);
|
|
digits++;
|
|
}
|
|
|
|
/* Decrement to get the number of trailing zeroes to print */
|
|
|
|
prec -= nchars;
|
|
}
|
|
|
|
/* Finally, print any trailing zeroes */
|
|
|
|
zeroes(obj, prec);
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|