Re: [Mesa3d-dev] GSOC: Gallium R300 driver

[Tom S. <tst...@gm...>]

On Wed, Mar 31, 2010 at 04:34:48AM +0200, Marek Olšák wrote:
> On Tue, Mar 30, 2010 at 10:26 AM, Nicolai Haehnle <nha...@gm...>wrote:
> >
> > Note that my Git repository already contains an implementation of
> > branch emulation and some additional optimizations, see here:
> > http://cgit.freedesktop.org/~nh/mesa/log/?h=r300g-glsl<http://cgit.freedesktop.org/%7Enh/mesa/log/?h=r300g-glsl>
> >
> > Shame on me for abandoning it - I should really get around to make
> > sure it fits in with recent changes and merge it to master. The main
> > problem is that it produces "somewhat" inefficient code. Adding and
> > improving peephole and similar optimizations should help tremendously.
> >
> 
> Well it's either this or nothing so I guess I am not the only one to prefer
> to get it merged. ;) However that kinda slightly changes Tom's plan for the
> GSoC project.
> 
> On a different note, considering that the r300 compiler has basically 2
> frontends (Mesa IR and TGSI) and 3 backends (r300 VS & FS, r500 FS), would
> it be feasible to add yet another backend - TGSI? That would turn the
> compiler into a generic Gallium shader optimizer with the lowering tools it
> already has (or will have) and more people would be interested in adding new
> features and improvements in it.
> 

Implementing branch emulation with TGSI was something I have been
thinking about doing, so maybe it would make sense to try and focus
on doing more of the optimizations with TGSI and creating a generic
Gallium shader optimizer, like you said.  Even though Nicolai's branch
only involves the r300 compiler, it will still be a good guide for me
if I am implementing something similar with TGSI.

-Tom