fixup! [LV] Vectorize Epilogues for loops with small VF but high IC

Author: juliannagele

llvm/lib/Transforms/Vectorize/LoopVectorizationPlanner.h

@@ -471,6 +471,8 @@ class LoopVectorizationPlanner {
   bool isMoreProfitable(const VectorizationFactor &A,
                         const VectorizationFactor &B) const;
 
+  /// Returns true if the per-lane cost of VectorizationFactor A is lower than
+  /// that of B in the context of vectorizing a loop with known \p MaxTripCount.
   bool isMoreProfitable(const VectorizationFactor &A,
                         const VectorizationFactor &B,
                         const unsigned MaxTripCount) const;

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -1537,6 +1537,8 @@ class LoopVectorizationCostModel {
   /// Returns true if epilogue vectorization is considered profitable, and
   /// false otherwise.
   /// \p VF is the vectorization factor chosen for the original loop.
+  /// \p Multiplier is an aditional scaling factor applied to VF before
+  /// comparing to EpilogueVectorizationMinVF.
   bool isEpilogueVectorizationProfitable(const ElementCount VF,
                                          const unsigned Multiplier) const;