[llvm] [LoopVectorizer] Add support for partial reductions (PR #92418)

[Florian Hahn via llvm-commits]

================
@@ -293,6 +293,19 @@ struct FixedScalableVFPair {
   bool hasVector() const { return FixedVF.isVector() || ScalableVF.isVector(); }
 };
 
+struct PartialReductionChain {
----------------
fhahn wrote:

Document?

https://github.com/llvm/llvm-project/pull/92418