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Fix more floating point formatting bugs

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git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5013 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2012-08-06 14:38:47 +00:00
parent 495c45d4f6
commit 4346670013
3 changed files with 105 additions and 40 deletions
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2
ChangeLog
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@ -3129,4 +3129,6 @@
point numbers (conversions are fine, but presentation was bad). This
is a critical bug fix if you use printf or sprintf to deal with floating
point numbers.
* lib/stdio/lib_libdtoa.c and lib_libvsprintf.c: Correct some floating
point options.

139
lib/stdio/lib_libdtoa.c
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@ -48,6 +48,8 @@
* Pre-processor Definitions
****************************************************************************/
#define MAX_PREC 16
#ifndef MIN
# define MIN(a,b) (a < b ? a : b)
#endif
@ -107,7 +109,20 @@ static void zeroes(FAR struct lib_outstream_s *obj, int nzeroes)
*
* Description:
* This is part of lib_vsprintf(). It handles the floating point formats.
* This version supports only the &f (with precision).
* 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.
*
****************************************************************************/
@ -146,10 +161,10 @@ static void lib_dtoa(FAR struct lib_outstream_s *obj, int fmt, int prec,
{
obj->put(obj, '-');
}
/* Always print at least one digit to the right of the decimal point. */
prec = MAX(1, prec);
else if (IS_SHOWPLUS(flags))
{
obj->put(obj, '+');
}
/* Special case exact zero or the case where the number is smaller than
* the print precision.
@ -160,53 +175,101 @@ static void lib_dtoa(FAR struct lib_outstream_s *obj, int fmt, int prec,
/* kludge for __dtoa irregularity */
obj->put(obj, '0');
obj->put(obj, '.');
}
else if (expt <= 0)
{
obj->put(obj, '0');
obj->put(obj, '.');
/* Print leading zeros */
/* A decimal point is printed only in the alternate form or if a
* particular precision is requested.
*/
if (expt < 0)
if (prec > 0 || IS_ALTFORM(flags))
{
nchars = MIN(-expt, prec);
zeroes(obj, nchars);
prec -= nchars;
obj->put(obj, '.');
/* Always print at least one digit to the right of the decimal point. */
prec = MAX(1, prec);
}
/* Print the significant digits */
nchars = MIN(numlen, prec);
for (i = nchars; i > 0; i--)
{
obj->put(obj, *digits);
digits++;
}
/* Decremnt to get the number of trailing zeroes to print */
prec -= nchars;
}
/* A non-zero value will be printed */
else
{
/* Print the integer part */
for (i = expt; i > 0; i--)
/* Handle the case where the value is less than 1.0 (in magnitude) and
* will need a leading zero.
*/
if (expt <= 0)
{
obj->put(obj, *digits);
digits++;
/* 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;
}
}
/* Print the decimal place */
/* Handle the general case where the value is greater than 1.0 (in
* magnitude).
*/
obj->put(obj, '.');
else
{
/* Print the integer part to the left of the decimal point */
/* Print the decimal */
for (i = expt; i > 0; i--)
{
obj->put(obj, *digits);
digits++;
}
numlen -= expt;
nchars = MIN(numlen, prec);
/* 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--)
{

4
lib/stdio/lib_libvsprintf.c
View File

@ -1587,7 +1587,7 @@ int lib_vsprintf(FAR struct lib_outstream_s *obj, FAR const char *src, va_list a
/* Perform left field justification actions */
prejustify(obj, fmt, flags, width, dblsize);
prejustify(obj, fmt, 0, width, dblsize);
/* Output the number */
@ -1595,7 +1595,7 @@ int lib_vsprintf(FAR struct lib_outstream_s *obj, FAR const char *src, va_list a
/* Perform right field justification actions */
postjustify(obj, fmt, flags, width, dblsize);
postjustify(obj, fmt, 0, width, dblsize);
#else
/* Output the number with a fixed precision */