Open-Source ATI R300 Compiler Optimizations

[phoronix]

Phoronix: Open-Source ATI R300 Compiler Optimizations

Being worked on this past summer were improvements to the open-source ATI R300 driver when it comes to GLSL compiler optimizations. This work was done by Tom Stellar as part of Google's Summer of Code for student developers. While we reported on some of the R300 compiler improvements back in June, there hasn't been too much more information to pass along, especially as the summer is now over. However, there is now a new branch by Stellar containing some additional optimizations...

http://www.phoronix.com/vr.php?view=ODc2NA

[xeros]

GLSL compiler in r300g is already working great but further optimizations are always welcome :-)
What should user experience from these optimizations? Better performance or better compatibility with games?

[JeanPaul145]

GLSL compiler in r300g is already working great but further optimizations are always welcome :-)
What should user experience from these optimizations? Better performance or better compatibility with games?

If it truly is an optimization, then it will increase performance, while retaining the same amount of GL-enabled compatibility.

So the article truly is talking about the r300g driver then? I already thought it was with the article referencing GLSL and R300c being all but dead and all, but you never know if some independent coder optimizes R300c just for the hell of it

Also, is there any word on how easily these optimizations can be ported/applied on r600g?

[xeros]

So the article truly is talking about the r300g driver then? I already thought it was with the article referencing GLSL and R300c being all but dead and all, but you never know if some independent coder optimizes R300c just for the hell of it

The article says about r300 but I think it's refering to r300g instead of r300 (r300c) as r300c has no GLSL (or maybe it does not do GLSL only for r300 hardware?). Does anyone know if r300c have GLSL on R400/R500 hardware?

[marek]

Tom is talking about the r300 compiler, which is shared between classic and gallium, but those optimizations are more important for GLSL which is only supported by the r300g driver. This work may improve shader sizes in classic as well, yeah.

These are r300(up to r500)-specific optimizations. They cannot be ported for r600, the hardware is vastly different.

[curaga]

Michael, please don't copy-paste typos verbatim

subtact -> subtract

[smitty3268]

It's possible this could result in bug fixes as well, if the shaders were previously running into hardware limitations and are now small enough to be run on older hardware. I'm not sure if that's happening much or not.