On Mon, Oct 27, 2003 at 04:37:30PM +0200, Ingo Oeser wrote:

On Saturday 25 October 2003 21:17, Jeff Garzik wrote:

quoted

Graphics processors are growing more general, too -- moving towards
generic vector/data processing engines.  I bet you'll see an optimal
model emerge where you have some sort of "JIT" for GPU microcode in
userspace.  Multiple apps pipeline X/GL/hardware commands into the JIT,
which in turn pipelines data and microcode commands to the GPU kernel
driver.

These "JIT" is needed also for another reason: 

	There are contraints for GPU commands and the pipelines need to
	be modelled, like CPU piplines are modelled in a compiler. But
	more like the pipelines of some early long instruction word
	processors, where issuing to a used pipeline will cause random
	behavior and crashes. So the JIT doesn't should also emit
	synchronization points. 

With this JIT in place, there need to be just some hardware description
files (backends) and some API (GL, DirectX, X) description files
(frontends).

I agree 60%  ;-)   This JIT emits GPU-specific microcode, so it should
lean towards being hardware-dependent.  Speed and efficiency IMO demand
that.

Looking at existing, open-source CPU JITs, there are certainly general
pieces and CPU-specific pieces.  But for GPUs, I think the best method
is to start at the more-GPU-specific end of the spectrum, and _evolve_
towards a more general solution, as hardware needs dictate.

In other terms, let the hardware drive the JIT design and evolution, and
don't over-design for a future that may never come.  That was part of
GGI's problem, IMO.

Now we just need some funding for that and the datasheets. Then it's
doable.

Yep ;-)

I see just one showstopper: Cheating in benchmarks isn't possible anymore.

PS: That's basically the GGI approach taken further.

I followed GGI for a while.  Trying to be all things to all people was
their principle mistake.  As Pat Morita said in Karate Kid,
"Focus, Daniel-san!"  Be specific before general.

	Jeff





-------------------------------------------------------
This SF.net email is sponsored by: The SF.net Donation Program.
Do you like what SourceForge.net is doing for the Open
Source Community?  Make a contribution, and help us add new
features and functionality. Click here: http://sourceforge.net/donate/