GLSL-To-TGSI For Mesa Is Still Not Merged

[phoronix]

Phoronix: GLSL-To-TGSI For Mesa Is Still Not Merged

Last month it was announced that the GLSL IR to TGSI translator for Mesa that avoids the use of the inefficient and old Mesa IR was ready to be merged. A month later, the code for this core Mesa improvement hasn't been pulled...

http://www.phoronix.com/vr.php?view=OTY2Mw

[Plombo]

For the answer to why it hasn't been merged, see my reply on the mailing list:

Last month, I was trying to get it merged before the 7.11 merge window
closed. When that didn't happen, I decided to stop being in a hurry and
instead make some more improvements before trying again to get it merged
to master. Also, Brian Paul pointed out an issue that I hadn't noticed
before where st/mesa needed the current fragment shader to be in Mesa IR
form for glBitmap, glDrawPixels, and glCopyPixels to work correctly.

All of that is done now, as I finished the glBitmap path on Sunday and
the DrawPixels/CopyPixels path on Saturday. So now I need to fix a few
minor things like commit messages and one case where the old path
generates better code than glsl_to_tgsi. The merge might also be
delayed a bit further if it's decided that it should wait until after
7.11 is released, as Ian's reply suggested.

[Plombo]

Wow, not much discussion here...

[darkbasic]

There is nothing to discuss, they will not merge it until mesa 7.11 gets released
If you have some benchmarks with and without GLSL-To-TGSI it would be much more interesting

[Michael]

If you have some benchmarks with and without GLSL-To-TGSI it would be much more interesting

I might be running some.

[Plombo]

There is nothing to discuss, they will not merge it until mesa 7.11 gets released

Not necessarily, Ian's message just said it should wait until after 7.11 if the changes would make it harder to cherry-pick changes to 7.11. I'm not convinced that's the case - there are only 2 existing files with major changes in core Mesa, and even those wouldn't make it difficult to backport fixes to 7.11.

I sent a reply to Ian's message to the list yesterday; it'll probably be discussed more if I get it ready before Mesa 7.11 is released on July 22. Which is likely, since all I really have to do is rebase against master and rewrite some of the commit messages. So we'll see.

If you have some benchmarks with and without GLSL-To-TGSI it would be much more interesting

I might be running some.

If you do, please be sure to test several different Gallium drivers (at least r300g/r600g/nvfx/nv50), since each driver compiles and optimizes the TGSI input differently (and they use different flags to make the compiler run different lowering passes and generate different TGSI).

[darkbasic]

I might be running some.

Awesome

[Michael]

If you do, please be sure to test several different Gallium drivers (at least r300g/r600g/nvfx/nv50), since each driver compiles and optimizes the TGSI input differently (and they use different flags to make the compiler run different lowering passes and generate different TGSI).

My plan for now is at least r300g, r600g, and nv50. Also to be monitoring CPU and GPU usage during so.

[darkbasic]

How do you monitor gpu usage? Does dynpm expose such information through debugfs?

[Michael]

How do you monitor gpu usage? Does dynpm expose such information through debugfs?

For the Radeon driver, the Phoronix Test Suite can monitor the fence count as a basic way to judge load (unfortunately, doesn't have a percentage-based load indicator like is exposed through Catalyst).