[Mesa-dev] radeonsi: NIR - Polaris triangle sprinkling running UH SOLVED - finally

[Dieter Nützel]

Am 16.02.2019 03:56, schrieb Timothy Arceri:
> On 13/2/19 8:28 am, Dieter Nützel wrote:
>> Hello Marek, Timo, Nicolai,
>> 
>> Timo SOLVED this long-standing NIR corruption on Polaris with his 
>> 'nir: rewrite varying component packing' commit.
>> 
>> It was triggered with
>> 
>> commit 86b52d42368ac496fe24bc6674e754c323381635
>> Author: Marek Olšák <marek.olsak at amd.com>
>> Date:   Fri Jul 13 00:23:36 2018 -0400
>> 
>>      radeonsi: reduce LDS stalls by 40% for tessellation
>> 
>>      40% is the decrease in the LGKM counter (which includes SMEM too)
>>      for the GFX9 LSHS stage.
>> 
>>      This will make the LDS size slightly larger, but I wasn't able to 
>> increase
>>      the patch stride without corruption, so I'm increasing the vertex 
>> stride.
>> 
>> and now finally SOLVED with
>> 
>> commit 26aa460940f6222565ad5eb40a21c2377c59c3a6
>> Author: Timothy Arceri <tarceri at itsqueeze.com>
>> Date:   Mon Dec 10 10:23:51 2018 +1100
>> 
>>      nir: rewrite varying component packing
>> 
>>      There are a number of reasons for the rewrite.
>> 
>>      1. Adding support for packing tess patch varyings in a sane way.
>> 
>>      2. Making use of qsort allowing the code to be much easier to
>>         follow.
>> 
>>      3. Fixes a bug where different interp types caused component
>>         packing to be skipped for all varyings in some scenarios.
>> 
>>      4. Allows us to add a crude live range analysis for deciding
>>         which components should be packed together. This support can
>>         optionally be added in a future patch.
>> 
>>      Reviewed-by: Jason Ekstrand <jason at jlekstrand.net>
>> 
>> Maybe it should backported (Cc: <mesa-stable at 
>> lists.freedesktop.org>) ) for 19.0?
> 
> I'd rather it didn't since NIR isn't default for radeonsi and this is
> use for other drivers like RADV. I'd rather have more testing in the
> dev branch.

Of course, your're right. - Running NIR to long...;-)

Dieter

BTW
'New' stuttering (shader compiler) with Rocket League went in.
Our son is unhappy. Have to dig (bisect).

> This change really shouldn't fix anything, it could just be that the
> change avoids the bug. I'm really not sure.
> 
> One thing this change did fix was a bug with doubles, but I wasn't
> aware of anything actually using doubles so I doubt this is it.
> 
>> 
>> I hope my bisect help to bring some more understanding for this 
>> Polaris NIR bug.
>> 
>> Now, hunting for the (last) 19.0+ EQAA regression (DiRT Rally, black 
>> squares like  radv/DXVK corruption, NOT NIR related) and 'meson' 
>> OpenCL (Clover) build error.
>> 
>> Greetings,
>> Dieter