On Wed, Dec 22, 2021 at 08:56:12PM +0200, Andy Shevchenko wrote:

On Wed, Dec 22, 2021 at 8:38 PM Liam Beguin [off-list ref] wrote:

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

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

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-               tmp = 1 << *val2;

At some point this should be BIT()

Forgot to add, If it's 64-bit, then BIT_ULL().

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

You may add a comment. You may use int_pow(), but it will be suboptimal.

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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;

No, it's about the _left_ operand.
I haven't checked if tmp is 64-bit, then even that would be still wrong.

Okay so your recommendation is to not use a left shift?

I can look into that but given how unlikely it is to fall into those bad
cases, I'd rather keep things as they are. Would that be okay?

Also, I don't think using BIT() or BIT_ULL() would address this as they
both do the same shift, with no extra checks.

Cheers,
Liam

-- 
With Best Regards,
Andy Shevchenko