Etnaviv Gallium3D Switches Over To NIR By Default

[phoronix]

Phoronix: Etnaviv Gallium3D Switches Over To NIR By Default

It's been a while since last having any major progress to report on Etnaviv, the open-source Mesa Gallium3D driver supporting Vivante graphics IP. But a rather fundamental change was made this past week in that Etnaviv is now (finally) using NIR by default...

https://www.phoronix.com/scan.php?page=news_item&px=Etnaviv-NIR-Default

[Aryma]

so the new 4-7 gen driver will benefit from this too ?

[boxie]

so the new 4-7 gen driver will benefit from this too ?

If you are asking about Intel gen 4-7 - No, this driver is for Vivante hardware.

[microcode]

I wonder how long until all the maintained drivers are TGSI-free; congratulations to whoever gets to delete that code. :+ )

[dcbaker]

so the new 4-7 gen driver will benefit from this too ?

i965 has been using NIR longer than any other driver (Intel started NIR, after all), crocus and iris have both used NIR only since day 1.

I wonder how long until all the maintained drivers are TGSI-free; congratulations to whoever gets to delete that code. :+ )

Unfortunately the answer is "never", both virgl and the vmware driver use tgsi as an interchange format between the host and client, which it's actually pretty good for. That means that we'll never get to delete TGSI completely, but it probably will move to an optional helper library at some point for just vmwgfx and virgl to consume.

[W.Irrkopf]

Unfortunately the answer is "never", both virgl and the vmware driver use tgsi as an interchange format between the host and client, which it's actually pretty good for. That means that we'll never get to delete TGSI completely, but it probably will move to an optional helper library at some point for just vmwgfx and virgl to consume.

Maybe you can elaborate on that a bit more (my current understanding is too superficial):
- The patch that got merged is basically a part of a larger project to replace glsl-to-tgsi by glsl-to-nir + nir-to-tgsi
- How can tgsi go away at all?
- Does this mean that for those drivers that are using the new way don't need to be aware of tgsi any more as the remaining part is part of "generic" mesa?
- To which extent is that approach applicable to the paravirtualization drivers? Does it matter whether the tgsi is generated the "old" way or the "new" way?

[dcbaker]

The goal would be that TGSI would be *just* part of virgl and vmwgfx. Ideally that would mean that they would consume NIR, and run the ntt (NIR to TGSI) internally before sending out TGSI as a serialized format) then the other end would do whatever with it. But core gallium helpers would directly output NIR instead of TGSI, and all drivers would consume NIR directly.