On Wed, Dec 22, 2021 at 02:38:13PM +0200, Andy Shevchenko wrote:

On Wed, Dec 22, 2021 at 5:47 AM Liam Beguin [off-list ref] wrote:

quoted

From: Liam Beguin <redacted>

The iio-rescale driver supports various combinations of scale types and
offsets. These can often result in large integer multiplications. Make
sure these calculations are done right by adding a set of kunit test
cases that build on top of iio-test-format.

...

quoted

+       int fract_mult = 100000000LL;

Perhaps also change to use the prefix?

Argh.. I missed this file. Sorry, will update.

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quoted

+       *nano = (s64)tmp * 10 * fract_mult + tmp2;

I'm also puzzled what the meaning of the 10 is here?

That comes from iio_str_to_fixpoint().
I sould've added a comment to make it more explicit as details escape me
right now...  Will fix.

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quoted

+       err = 1000000 * abs(exp - real);

Prefix?

Ok

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quoted

+       err = div64_u64(err, abs(exp));
+       return (int)err;

return div64_u64();

will do.

Cheers,
Liam

-- 
With Best Regards,
Andy Shevchenko