[llvm-branch-commits] [llvm] [VPlan] Scalarize to first-lane-only directly on VPlan (PR #184267)

[Ramkumar Ramachandra via llvm-branch-commits]

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@@ -485,6 +485,12 @@ struct VPlanTransforms {
                                          VPRecipeBuilder &RecipeBuilder,
                                          VPCostContext &CostCtx,
                                          LoopVectorizationLegality &Legal);
+
+  /// Make VPlan-based scalarization decision prior to delegating to the ones
+  /// made by the legacy CM. Only transforms "usesFirstLaneOnly` def-use chains
+  /// enabled by prior widening of consecutive memory operations for now.
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artagnon wrote:

Is it possible to make all scalarization decisions in VPlan, stripping the legacy CM completely? That would make the patch more compelling?

https://github.com/llvm/llvm-project/pull/184267