Re: [PATCH v3 1/4] iio: prepare iio_format_value to handle higher-precision IIO_VAL_DECIMAL64_* formats

[Andy Shevchenko]

On Mon, Oct 26, 2026 at 11:51:11AM -0500, Victor Chernyakin wrote:
> Prepare iio_format_value for an upcoming patch that adds formats up
> to IIO_VAL_DECIMAL64_YOCTO (a scale of 24 digits) by avoiding
> computing 10^scale when doing so would overflow, and by avoiding
> undefined behavior due to abs(LLONG_MIN) (which couldn't happen
> previously).

...

> +#define GREATEST_POWER_OF_10_THAT_FITS_IN_S64 18

It's an interesting name for log10(2^63).

This, along with log10(2^64 - 1) should be added as definitions at least
IIO-wide. There is a series that wanted similar for u64.

-- 
With Best Regards,
Andy Shevchenko