[Mesa-dev] [PATCH 00/16] gallium: add support for NIR as alternate IR

[Rob Clark]

On Wed, Apr 6, 2016 at 8:34 AM, Emil Velikov <emil.l.velikov at gmail.com> wrote:
> Hi Rob,
>
> If I'm reading the series correctly, NIR will only be used with vertex
> and fragment shaders. Is there much left to make freedreno (vc4?)
> "tgsi-free" ? Both driver side and state-tracer/nir ? Or you plan is
> to keep the TGSI code paths around just in case ?

fwiw, I didn't wire up other stages since I don't really have a way to
test them yet, but they should be simpler than FS/VS since there
aren't shader variants to lower.  I guess probably the next stage to
wire up would be compute.

As far as tgsi-free, I'm not sure that is possible, since (a) other
state trackers, and (b) internally generated blit shaders and ARB
program shaders.  (I guess we could use prog_to_nir, but those shaders
tend to be less complex and it didn't seem as important to bypass
tgsi.)  So I think for NIR consuming drivers, tgsi_to_nir will stick
around, but at least it should be only needed for simpler stuff... we
should at least be able to avoid having to teach ttn about features
more advanced than what it has now (ie. compute (functions/images/??),
mediump, etc)

BR,
-R