[Mesa-dev] [PATCH v2 00/31] Nir support for Nouveau

[Jason Ekstrand]

On January 4, 2018 14:02:25 Ilia Mirkin <imirkin at alum.mit.edu> wrote:

> On Thu, Jan 4, 2018 at 2:57 PM, Karol Herbst <kherbst at redhat.com> wrote:
>> On Thu, Jan 4, 2018 at 8:56 PM, Jason Ekstrand <jason at jlekstrand.net> wrote:
>>> What is the nature of the immediate problem?  We may have a similar issue.
>>
>>  we don't do rescheduling, so all the immediates are at the top of the shader.
>
> The implication being that any values that are initialized to an
> immediate (which is not infrequent) are done so at the top of the
> shader, extending live ranges dramatically.
>
> It's not difficult to move them somewhere closer to first use, just
> needs to be done.

I think our back-end compiler's copy propagation and constant communication 
passes handle that for us fairly well.  The primary place it's likely to 
still be an issue for is loop counters and the like.