Re: [Mesa3d-dev] dynamic code generation with gcc

[Gareth H. <ga...@va...>]

Keith Whitwell wrote:
> 
> I agree with this, but I'm inclined to persue gcc-based codegen, at least as a
> prototype for a more hard-wired system to follow it.  I think we need to make
> some progress in this area, and gcc looks like it's got a real low entry
> level.

Fair enough.  I just hadn't thought it would be worth going to that
amount of trouble, but there are obvious advantages in doing so.

> It might be possible to use a tokenized generation language that can either be
> expanded by the C preprocessor, or understood explicitly by a follow-on
> bespoke codegen module.
> 
> Some of the optimizations for the tnl functions like you've got above, such as
> hardwiring addresses, using the right (ie non -fPIC) compiler options, can be
> acheived using gcc.
> 
> So in short, I don't know whether the overhead of gcc will be a problem at
> runtime, but the low overhead for us right now makes it look like a real
> attractive way to get started.  If it works out ok at runtime, we've finished
> unexpectedly early.

I'm putting the finishing touches on the driver tnl module code that
goes along with the core Mesa stuff I committed yesterday, so once
that's done I might play with this a little (at least get some basic
generation happening).

-- Gareth