[llvm] [RISCV] Match strided vector bases in RISCVGatherScatterLowering (PR #93972)

[Kolya Panchenko via llvm-commits]

nikolaypanchenko wrote:

I do understand that this is more general peephole optimization, but more accurate one will be to teach vectorizer to emit strided intrinsics, like (vp.strided.load)[https://llvm.org/docs/LangRef.html#llvm-experimental-vp-strided-load-intrinsic]. Or, otherwise, provide indexes analysis that cost model can use to accurately estimate such accesses.

JFYI: we  have a plan to upstream support of strided accesses for EVL vectorization by leveraging these intrinsics.

https://github.com/llvm/llvm-project/pull/93972