On Wed, Dec 22, 2021 at 02:29:04PM +0200, Andy Shevchenko wrote:

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

quoted

From: Liam Beguin <redacted>

Reduce the risk of integer overflow by doing the scale calculation on
a 64-bit integer. Since the rescaling is only performed on *val, reuse
the IIO_VAL_FRACTIONAL_LOG2 case.

...

quoted

-               tmp = 1 << *val2;

At some point this should be BIT()

I'm not against changing this, but (to me at least) 1 << *val2 seems
more explicit as we're not working with bitfields. No?

Rule of thumb (in accordance with C standard), always use unsigned
value as left operand of the _left_ shift.

Right, that makes sense! In practice though, since we'll most likely
never use higher bits of *val2 with IIO_VAL_FRACTIONAL_LOG2, would it be
enough to simply typecast?

	tmp = 1 << (unsigned int)*val2;

Cheers,
Liam

quoted

+               if (scale_type == IIO_VAL_FRACTIONAL)
+                       tmp = *val2;
+               else
+                       tmp = 1 << *val2;

-- 
With Best Regards,
Andy Shevchenko