[llvm] SLPVectorizer: vectorize lrint, llrint (PR #69945)

[David Green via llvm-commits]

https://github.com/davemgreen commented:

My understanding is that the changes in isTriviallyVectorizable will alter the LoopVectorizer and Scalarization too. 

Can you add some tests to make sure they work, similar to https://reviews.llvm.org/D124358.

https://github.com/llvm/llvm-project/pull/69945