Re: [Intel-gfx] [PATCH v1 1/1] drm/i915/selftests: Replace too verbose for-loop with simpler while

[Jani Nikula <jani.nikula@linux.intel.com>]

On Tue, 15 Feb 2022, Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:
> On Tue, Feb 15, 2022 at 07:14:49PM +0200, Jani Nikula wrote:
>> On Tue, 15 Feb 2022, Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:
>> > It's hard to parse for-loop which has some magic calculations inside.
>> > Much cleaner to use while-loop directly.
>> 
>> I assume you're trying to prove a point following our recent
>> for-vs-while loop discussion. I really can't think of any other reason
>> you'd end up looking at this file or this loop.
>> 
>> With the change, the loop indeed becomes simpler, but it also runs one
>> iteration further than the original. Whoops.
>
> Yeah, sorry for that, the initial condition should be d = depth - 1,
> of course.

Well, no, the condition should be while (--i) instead to also match the
values the original loop takes. ;D

Cheers,
Jani.


>
>> It's a selftest. The loop's been there for five years. What are we
>> trying to achieve here? So we disagree on loops, fine. Perhaps this is
>> not the best use of either of our time? Please just let the for loops in
>> i915 be.
>
> Yes, I'm pretty much was sure that no-one will go and apply this anyway
> (so I haven't paid too much attention), but to prove my point in the
> certain discussion.
>
> And yes, the point is for the new code, I'm not going to change existing
> suboptimal and too hard to read for-loops, it will consume my time later
> when I will try to understand the code.

-- 
Jani Nikula, Intel Open Source Graphics Center