[llvm] [InstCombine] Canonicalize `abs(sub(ext(X),ext(Y)))` -> `ext(sub(max(X,Y),min(X,Y)))` (PR #162296)

[Nikita Popov via llvm-commits]

nikic wrote:

That would be a question for @fhahn. The loop vectorizer has some support for narrowing values, but I'm not sure where this kind of more complex pattern would fit in.

https://github.com/llvm/llvm-project/pull/162296