[llvm] [VPlan] Create epilogue minimum iteration check in VPlan. (PR #157545)

[via llvm-commits]

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@@ -7405,124 +7391,27 @@ BasicBlock *EpilogueVectorizerMainLoop::emitIterationCountCheck(
 // EpilogueVectorizerEpilogueLoop
 //===--------------------------------------------------------------------===//
 
-/// This function is partially responsible for generating the control flow
-/// depicted in https://llvm.org/docs/Vectorizers.html#epilogue-vectorization.
+/// This function creates a new scalar preheader, using the previous one as
+/// entry block to the epilogue VPlan. The minimum iteration check is already
+/// created in VPlan.
 BasicBlock *EpilogueVectorizerEpilogueLoop::createVectorizedLoopSkeleton() {
+  BasicBlock *OriginalScalarPH = OrigLoop->getLoopPreheader();
   BasicBlock *ScalarPH = createScalarPreheader("vec.epilog.");
----------------
ayalz wrote:

```suggestion
  BasicBlock *NewScalarPH = createScalarPreheader("vec.epilog.");
  BasicBlock *OriginalScalarPH = NewScalarPH->getSinglePredecessor();
```
?

https://github.com/llvm/llvm-project/pull/157545