Re: [PATCH v7 2/3] cmdline: add floating point support

["Burakov, Anatoly" <anatoly.burakov@intel.com>]

On 5/8/2025 12:01 PM, Anatoly Burakov wrote:
> Add support for parsing floating point numbers in cmdline library, as well
> as unit tests for the new functionality. Use C library for parsing.
> 
> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
> ---
> 
> Notes:

v6 -> v7:
- Fixed a bug in float compare in unit tests where a bigger epsilon
   value than necessary was "needed" because we were comparing float
   result to a double result

>      v5 -> v6:
>      - Small refactor to reduce amount of noise
>      - Use strtof for parsing single precision floats
>      - More unit tests
>      
>      v4 -> v5:
>      - Reworked to use standard C library functions as much as possible,
>        keeping near-100% compatibility with earlier versions (the only
>        difference is that strings like "+4" are now considered valid)
>      
>      v3 -> v4:
>      - Removed unnecessary check for integer overflow when parsing negative
>        floats (as we convert to double before changing sign)
>      - Make naming of float exponent states more consistent
>      
>      v2 -> v3:
>      - Fixed a bug where a free-standing negative exponent ("1e-") would attempt to be
>        parsed, and added unit tests for this case
>      - Added support for floats in dpdk-cmdline-gen script
>      - Added documentation updates to call out float support
> 
>   app/test/test_cmdline_num.c            | 284 ++++++++++++++++++++++++-
>   buildtools/dpdk-cmdline-gen.py         |  24 ++-
>   doc/guides/prog_guide/cmdline.rst      |   3 +
>   doc/guides/rel_notes/release_25_07.rst |   5 +
>   lib/cmdline/cmdline_parse_num.c        |  67 +++++-
>   lib/cmdline/cmdline_parse_num.h        |   4 +-
>   6 files changed, 368 insertions(+), 19 deletions(-)
> 

...but forgot to remove the comment:

> +static int
> +float_cmp(double expected, void *actual_p, enum cmdline_numtype type)
> +{
> +	double eps;
> +	double actual_d;
> +
> +	if (type == RTE_FLOAT_SINGLE) {
> +		/* read as float, convert to double */
> +		actual_d = (double)*(float *)actual_p;
> +		/* downcast expected to float as well */
> +		expected = (double)(float)expected;
> +		/* FLT_EPSILON is too small for some tests */

Please fix this on apply if there is no v8, thanks :)

> +		eps = FLT_EPSILON;
> +	} else {
> +		/* read as double */
> +		actual_d = *(double *)actual_p;
> +		eps = DBL_EPSILON;
> +	}
> +	/* compare using epsilon value */
> +	if (fabs(expected - actual_d) < eps)
> +		return 0;
> +	/* not equal */
> +	return expected < actual_d ? -1 : 1;
> +}
> +

-- 
Thanks,
Anatoly