[llvm] LV]: consider scalable VF during deciding dead epilogue. (PR #156724)

[Hassnaa Hamdi via llvm-commits]

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@@ -4407,6 +4407,13 @@ VectorizationFactor LoopVectorizationPlanner::selectEpilogueVectorizationFactor(
     LLVM_DEBUG(dbgs() << "LEV: Maximum Trip Count for Epilogue: "
                       << MaxTripCount << "\n");
   }
+  // Check if the RemainingIterations is scalable.
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hassnaaHamdi wrote:

About this suggestion:
`2. We add code in the loop to explicitly avoid comparing the next VF with remaining iterations if we don't expect a sensible answer.`
Do you mean that we skip the epilogue loop at that case ?

https://github.com/llvm/llvm-project/pull/156724