[llvm] [LV, VP]VP intrinsics support for the Loop Vectorizer + adding new tail-folding mode using EVL. (PR #76172)

[via llvm-commits]

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@@ -1511,7 +1513,9 @@ class LoopVectorizationCostModel {
 
   /// Selects and saves TailFoldingStyle for 2 options - if IV update may
   /// overflow or not.
-  void setTailFoldingStyles() {
+  /// \param IsScalableVF true if scalable vector factors enabled.
+  /// \param UserIC User specific interleave count.
+  void setTailFoldingStyles(bool IsScalableVF, unsigned UserIC) {
     assert(ChosenTailFoldingStyle.first == TailFoldingStyle::None &&
            ChosenTailFoldingStyle.second == TailFoldingStyle::None &&
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ayalz wrote:

nit (unrelated to this patch): `None` is a valid choice for setting a tail style; if it's important to assert that style is set only once, an `optional` could be used instead.

https://github.com/llvm/llvm-project/pull/76172