[LLVMdev] LLVM Loop Vectorizer

Nadav Rotem nrotem at apple.com
Fri Oct 5 13:22:40 PDT 2012

On Oct 5, 2012, at 1:14 PM, Eric Christopher <echristo at gmail.com> wrote:

> Nadav,
>>> 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.

Yes. I plan to start working on this new interface (TargetVectorData ?) as soon as we merge the tools. 

> Specific names or making "X
> class available to Y passes at Z level" can probably wait.


> -eric

Thanks :)

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