Re: [Mesa3d-dev] RFC: GSOC Proposal: R300/Gallium GLSL Compiler

[Marek O. <ma...@gm...>]

On Sun, Apr 4, 2010 at 12:10 AM, Zack Rusin <za...@vm...> wrote:

> I thought the initial proposal was likely a lot more feasible for a GSOC
> (of
> course there one has to point out that Mesa's GLSL compiler already does
> unroll loops and in general simplifies control-flow so the points #1 and #2
> are
> largely no-ops, but surely there's enough work on Gallium Radeon's drivers
> left to keep Tom busy). Otherwise having a well-defined and reduced scope
> with
> clear deliverables would be rather necessary for LLVM->TGSI code because
> that
> is not something that you could get rock solid over a summer.
>

It doesn't seem to simplify branches or unroll loops that much, if at all.
It fails even for the simplest cases like this one:

    if (gl_Vertex.x < 30.0)
        gl_FrontColor = vec4(1.0, 0.0, 0.0, 0.0);
    else
        gl_FrontColor = vec4(0.0, 1.0, 0.0, 0.0);

This gets translated to TGSI "as is", which is fairly... you know what.

-Marek