[llvm] [SystemZ, LoopVectorizer] Enable vectorization of epilogue loops after VF16. (PR #172925)

[Florian Hahn via llvm-commits]

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@@ -1932,8 +1932,9 @@ class TargetTransformInfo {
   LLVM_ABI bool preferPredicatedReductionSelect() const;
 
   /// Return true if the loop vectorizer should consider vectorizing an
-  /// otherwise scalar epilogue loop.
-  LLVM_ABI bool preferEpilogueVectorization() const;
+  /// otherwise scalar epilogue loop if the loop already has been vectorized
+  /// with VF x IC, running \p Iters scalar iterations per vector iteration.
+  LLVM_ABI bool preferEpilogueVectorization(ElementCount Iters) const;
 
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fhahn wrote:

```suggestion
  /// otherwise scalar epilogue loop if the loop already has been vectorized
  /// processing \p Iters scalar iterations per vector iteration.
  LLVM_ABI bool preferEpilogueVectorization(ElementCount Iters) const;

```

https://github.com/llvm/llvm-project/pull/172925