[Mesa-dev] Adjust MIMG writemask to only the used components

Christian König deathsimple at vodafone.de
Wed Apr 10 01:26:29 PDT 2013


Am 03.04.2013 15:43, schrieb Michel Dänzer:
> On Mit, 2013-04-03 at 15:38 +0200, Christian König wrote:
>> Am 03.04.2013 15:19, schrieb Michel Dänzer:
>>> On Mit, 2013-03-27 at 17:57 +0100, Christian König wrote:
>>>> the attached patches dynamically adjust the writemask of MIMG
>>>> instructions depending on the used components. Additional to that it
>>>> also adjust the register class of MIMG instruction so that we also
>>>> reduce register pressure.
>>> There's mainly one thing that isn't clear to me: My understanding from
>>> the ISA is that even if the instruction writemask operand has 'gaps',
>>> e.g. 0x9, the enabled components will always be written to consecutive
>>> VGPRs. So in this example, the instruction would write to two
>>> consecutive VGPRs, one for component 0/'x' and one for component 3/'w'
>>> of a four component vector. Is this handled correctly?
>>>
>> Yes your understanding is correct, and it is indeed handled correctly.
>>
>> I just analyze the used register components to figure out the needed
>> writemask and while doing so remember which instruction uses which
>> component. So after updating the writemask I just change the index of
>> the used component as well.
> Excellent. Sounds and looks good to me then.
>

Sorry for the delay, I was busy with UVD for the last few days.

Does that count as a reviewed by from your side?

Cheers,
Christian.



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