[LLVMdev] LLVM Loop Vectorizer

Eric Christopher echristo at gmail.com
Fri Oct 5 13:14:00 PDT 2012


>> Possibly, though I think TargetData should still be able to get you
>> what you want.
> TargetData does not have enough information for vectorization. For example, we need to ask the target if it has efficient "cos4" implementation or the cost of 'mult_4xf32'. We need lots of target specific information for deciding when to vectorize and which vectorization optimizations to apply.

Sure. I was mostly going with the idea of "insert some Targetish
structure here".

>> TargetData is pretty useful during opt if it's available, probably no
>> need to merge
>> the tools though.
> TargetData is useful, but not enough for vectorization.

I think an interface should be designed on top of the current sets of
data that will encompass what we may want at the target level and we
can make our decisions based on that. Specific names or making "X
class available to Y passes at Z level" can probably wait.


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