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

[Florian Hahn via llvm-commits]

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@@ -92,7 +92,47 @@ static bool verifyVPBasicBlock(const VPBasicBlock *VPBB,
   for (const VPRecipeBase &R : *VPBB)
     RecipeNumbering[&R] = Cnt++;
 
+  // Set of recipe types along with VPInstruction Opcodes of all EVL-related
+  // recipes that must appear at most once in Entry or Exiting blocks.
+  DenseSet<unsigned> EVLFound;
+  const VPlan *Plan = VPBB->getPlan();
+  bool IsHeader = Plan && Plan->getEntry()->getNumSuccessors() == 1 &&
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fhahn wrote:

Plan must always be set here I think? Why do we need to check the number of successors here?

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