[llvm] [LV]: Improve accuracy of calculating remaining iterations of MainLoopVF (PR #156723)

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git-clang-format --diff origin/main HEAD --extensions cpp -- llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
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``````````diff
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 68d28a5e6..287808df3 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -4381,7 +4381,8 @@ VectorizationFactor LoopVectorizationPlanner::selectEpilogueVectorizationFactor(
   // 'vscale'.
   // If TC is multiple of vscale, try to get estimated value:
   if (match(TC, m_scev_Mul(m_SCEV(), m_SCEVVScale()))) {
-    if (std::optional<ElementCount> BestKnownTC = getSmallBestKnownTC(PSE, OrigLoop)) {
+    if (std::optional<ElementCount> BestKnownTC =
+            getSmallBestKnownTC(PSE, OrigLoop)) {
       unsigned EstimatedRuntimeTC =
           estimateElementCount(*BestKnownTC, CM.getVScaleForTuning());
       TC = SE.getConstant(TCType, EstimatedRuntimeTC);

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https://github.com/llvm/llvm-project/pull/156723