[llvm] [SLP] Vectorize zero-tested OR/UMax reductions (PR #205473)

[Alexey Bataev via llvm-commits]

alexey-bataev wrote:

> I’ll update the implementation following your guidance. I’m sorry for taking up your time with multiple review rounds due to my lack of experience with the SLPVectorizer pass.

Not a problem; do not worry

https://github.com/llvm/llvm-project/pull/205473