[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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@@ -202,7 +202,58 @@ static bool verifyVPBasicBlock(const VPBasicBlock *VPBB,
   for (const VPRecipeBase &R : *VPBB)
     RecipeNumbering[&R] = Cnt++;
 
+  // Check if EVL recipes exist only in Entry block and only once.
+  DenseSet<unsigned> EVLFound;
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ayalz wrote:

Worth explaining that this is a set of Recipe **types** along with VPInstruction **Opcodes**, of all EVL-related recipes that must appear at-most once, in Entry or Exiting blocks.

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