Mesa 20.0 Lands A Load/Store Vectorizer As Latest "ACO" Backend Improvement

[phoronix]

Phoronix: Mesa 20.0 Lands A Load/Store Vectorizer As Latest "ACO" Backend Improvement

While the Radeon "ACO" compiler back-end performance is already looking very good in the speed department over the AMDGPU LLVM back-end for the Vulkan driver as shown in recent benchmarks, it's getting even better...

http://www.phoronix.com/scan.php?page=news_item&px=Mesa-20.0-ACO-Load-Store-Vec

[M@GOid]

Last week I updated mesa with Oibaf's PPA and noticed a big jump in performance on some older games, like American Truck Simulator and Assault Android Cactus, something about 20/30% more FPS. Yesterday some of those gains disappeared, it must have been some regression on other games.

[R41N3R]

Hope ACO will be enabled by default soon for RADV. It works absolutely fantastic so far!

[ntropy]

Aco is indeed amazing. I kept compiling mesa myself until aco merged, now I am using oibaf too with latest mesa 20. I have no games on a Vega 64 that dont run with a good 60 fps in 1080p, even Anthem does or Star Wars:Fallen Order. And that all with only microstutters on the first shader compile (barely noticeable, if you dont know).

Totally amazed to see how much more is possible to be squeezed out of the Vega to catch up a bit with nvidia. So much already happened and it shows how important it is to have a good code for your driver to get that fps up.

[tildearrow]

Typo:

In the patch enabling the vectorizer, it yielded a code decrease of around 13% less for NeiR:Automata and about 15% less generated code for GTA V.

[dcbaker]

Do users need to clear shader disk caches for the vectorizer to take effect?

if you ever have a collision in the shader cache that's a bug.

[You-]

his is response can be translated as:
"No*


*unless there is a bug"

[dcbaker]

his is response can be translated as:
"No*


*unless there is a bug"

Exactly. There are only two reasons to clear the shader cache:
1) It's gotten too big
2) there's a bug

In the case of "do I need to clear the cache to get a new features to work?" that bug would be that the shader compiled without said feature is colliding with the shader compiled with said feature.

[smitty3268]

I don't understand how is your response relevant in the context of my query.

If you update your version of Mesa, all old cache entries are automatically invalidated (barring a bug). Otherwise various changes could cause problems, so it has to work that way.