Evergreen documentation drop?

[DuSTman]

Hi..

I was wondering if/when there is going to be any more documentation drops for the evergreen. It's cool that we have the shader language docs, but without also having the register docs, there's not much one can do other than maybe work on adapting a shader compiler backend.

Is this information available under NDA, or something?

[bridgman]

First draft of a 3D register spec has been written and is being reviewed and tweaked now. I expect the first working-ish code will come out first, followed shortly after by the docs. No ETA yet because it depends on how many other projects the reviewers are juggling at the same time.

We kinda need to get at least basic driver functionality working before we know what to put in the documentation. The shader ISA doc comes out of the hardware development flow for new GPUs, but the rest of the programming guides are written specifically for open source driver development.

[DuSTman]

Oh. I kindof figured you'd just "sanitise" your internal documentation. Good news on the progress, anyway.

[bridgman]

Nope. The internal documentation is how the hardware is designed, not how to program it.

There are snippets which Alex can extract for the documentation, but most of it is written from scratch. If we wanted to teach a potential competitor how to design their own GPU to compete with ours, on the other hand, our internal documentation would be perfect

The register spec info can be extracted more directly, but until we have at least a semi-working driver we don't really know what portions of it are required... and trying to release the whole register spec would take literally years of review and discussion/investigation.

[DuSTman]

Fair enough.

That sounds like it'd be highly inconvenient for the Catalyst dev team as well, though. Might be prudent for both internal and external devs for the hardware team to produce a programming interface spec document?

[bridgman]

It doesn't work as well as you might think. The hardware and software devs for each hardware block are generally co-located and work together on the design of new hardware, so there wouldn't be that much benefit... so we would end up with a big stack of documentation that was expensive to produce and was only used once (or, more likely, a few times). It's hard to make the costs and benefits work out.

As the open source documentation and development activities catch up with internal developoment (remember we've had to essentially catch up on 8 years of HW development over the last 3 years) this will all get easier anyways.