[llvm] [AArch64] Add SVE shuffle optimization pass (PR #193951)

[David Green via llvm-commits]

https://github.com/davemgreen commented:

Where is the code coming from? If is from the vectorizer then the direction of travel recently has been to do the deinterleaving in VPlan (which has the added benefit of computing costs more accurately, not relying on ld4 being profitable enough).

Otherwise - new passes do cost more than existing passes, both in terms of the amount of code to maintain and the compile time cost of scanning code again and again.

https://github.com/llvm/llvm-project/pull/193951