[llvm] [LV] Add -fold-epilogue-tail option for tail-folded epilogue (PR #190697)

[David Sherwood via llvm-commits]

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@@ -804,6 +812,12 @@ enum EpilogueLowering {
   // Loop hint indicating an epilogue is undesired, apply tail folding.
   CM_EpilogueNotNeededFoldTail,
 
+  // Tail-folded vector epilogue requested; the scalar tail will be folded into
+  // the vectorized epilogue loop if possible, otherwise fall back to an
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david-arm wrote:

nit: Perhaps clearer to say "otherwise fall back to a normal epilogue"?

https://github.com/llvm/llvm-project/pull/190697