[Mesa-dev] [PATCH 1/2] i965/fs: Force promotion of src0 immediates.

[Matt Turner]

On Mon, Mar 16, 2015 at 2:44 PM, Kenneth Graunke <kenneth at whitecape.org> wrote:
> On Monday, March 16, 2015 07:54:45 AM Tapani Pälli wrote:
>> My first attempt to fix the bug 89569 was to add check in combine
>> constants but for some reason I did not get it to work. One reason is
>> that inst->sources cannot be trusted
>
> I certainly hope we can trust it.  If it's wrong, we need to fix that.

We don't bother changing inst->sources when we convert a MUL dst, x,
0.0 into a MOV, but we do set its last source to reg_undef so it's
safe.

We could update inst->sources. It would at least let us skip a few
iterations. It'd also make dump_instructions() output a bit prettier.