[PATCH] D22859: [X86][SSE] Enable target shuffle combining to combine multiple shuffle inputs.

[Andrea Di Biagio via llvm-commits]

andreadb added a comment.

Hi Simon,

Overall the patch lgtm.
My major concern was related to the complexity of your new algorithm. 'combineX86ShufflesRecursively' is now called for every "used" shuffle operand. Have you noticed any particular cases where this function is now expensive?
However, given that we already limit the maximum recursion depth to 8, I don't expect this to be much of an issue.

-Andrea


Repository:
  rL LLVM

https://reviews.llvm.org/D22859