[PATCH] Add support to vectorize ctlz, cttz and powi intrinsics in SLPVectorizer

[Nadav Rotem]

Hi Karthik, 

Thanks for working on it. It would be great to vectorize powi, ctlz and cttz. Why did you decide to use SCEV and not simply check the last argument for equality?

Thanks,
Nadav

http://reviews.llvm.org/D3851