[Mesa-dev] [PATCH 3/3] glsl: relax loop unrolling restrictions

[Marek Olšák]

On Thu, Jun 22, 2017 at 12:25 PM, Timothy Arceri <tarceri at itsqueeze.com> wrote:
> On 22/06/17 18:46, Samuel Pitoiset wrote:
>>
>> Here's a shader-db report:
>>
>> https://pastebin.com/raw/QBMnF2pv
>>
>> This doesn't sound like a total win actually...
>
>
> I'm surprised to see this. I thought we pretty much unrolled everything
> already, although maybe that was what happened after NIR unrolling.
>
> I've done a full shader-db run and I'm getting very different results from
> you:
>
> https://pastebin.com/XRH7Vbvv
>
> There are still a little mixed but they look much more positive.

The problem with our shader-db stats is that they have very little to do
with performance changes. The code size increase is expected. Ignore
register usage, instead, look at max waves. SGPR spilling is cheap -
measurements can be done to see whether it's measurable.

Marek