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

[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? 

-- 
Earthling Michel Dänzer           |                   http://www.amd.com
Libre software enthusiast         |          Debian, X and DRI developer