[PATCH] D25039: [X86][AVX] Ensure broadcast loads respect dependencies

[Simon Pilgrim via llvm-commits]

RKSimon added a comment.

Thanks Michael.



> mkuper wrote in X86ISelLowering.cpp:8684
> Why do we need the TokenFactor? The load is only used in the shuffle, right? So why can't we just replace Ld with V completely?
> Or do you prefer not to trust the load being DCE'd?

Yes, I don't trust the load being dealt with correctly - the problems I had with subvector broadcast all revolved around those cases. I've been wondering whether it'd be cleaner to split the broadcast op into register and memory intrinsic ops to avoid this but for now we just have (ugly) fallback cases as tablegen patterns.

Repository:
  rL LLVM

https://reviews.llvm.org/D25039