[Mesa-dev] Mesa (shader-work): glsl: introduce ir_binop_all_equal and ir_binop_any_equal, allow vector cmps

[Jakob Bornecrantz]

On Thu, Sep 9, 2010 at 12:22 AM, Luca Barbieri <luca at luca-barbieri.com> wrote:
>> And never mind that you can't make a conformant OpenGL driver with
>> Gallium due to the impossibility of software fallbacks.
>
> Well, you could use the failover module to use softpipe for fallbacks,
> but no one does, for the following reasons:
> 1. Modern hardware doesn't need any software fallbacks, and at most
> you need to "emulate" things with ad-hoc shaders (possibly compute
> shaders)
> 2. Software fallbacks are mostly useless because a terribly slow
> implementation is not significantly more useful than a broken uone

That being said the draw module handles all those fun special cases of
triangles, lines and quads already so its only when the rasterizer and
fragment shader can't handle things that we just do best effort.

Cheers Jakob.