[Mesa-dev] [PATCH 7/7] radeon/llvm: enable LICM and DCE pass

[Michel Dänzer]

On Mit, 2013-03-06 at 11:56 +0100, Christian König wrote: 
> Am 05.03.2013 18:32, schrieb Vincent Lejeune:
> > LICM stands for Loop Invariant Code Motion.
> > Instructions that does not depend of loop index are moved outside of loop body.
> > (This solves one of llvm generated code Vadim pointed in another thread)
> >
> > DCE is DeadCodeElimination...I don't know the difference between "classic" DCE and aggressive DCE though.
> 
> If I understand it correctly the DCE pass just removes the trivial dead 
> instructions, e.g. not used and doesn't have a side effect. While the 
> aggressive DCE pass goes a bit more into the depth. For example imagine 
> a loop with an unused variable incremented, the increment depends on 
> itself, but it's completely useless...

Thanks for the explanations guys, but the point is really that the
change needs to be self-explanatory. :)


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