[llvm] [VPlan] Set branch weight metadata on middle term in VPlan (NFC) (PR #143035)

[via llvm-commits]

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@@ -882,11 +882,39 @@ template <unsigned PartOpIdx> class VPUnrollPartAccessor {
   unsigned getUnrollPart(VPUser &U) const;
 };
 
+/// Helper to manage IR metadata for recipes. It filters out metadata that
+/// cannot be propagated.
+class VPIRMetadata {
+  SmallVector<std::pair<unsigned, MDNode *>> Metadata;
+
+public:
+  VPIRMetadata() {}
+
+  /// Adds metatadata that can be preserved from the original instruction
+  /// \p I.
+  VPIRMetadata(Instruction &I) { getMetadataToPropagate(&I, Metadata); }
+
+  /// Adds metatadata that can be preserved from the original instruction
+  /// \p I and noalias metadata guaranteed by runtime checks using \p LVer.
+  VPIRMetadata(Instruction &I, LoopVersioning *LVer);
+
+  /// Copy constructor for cloning.
+  VPIRMetadata(const VPIRMetadata &Other) : Metadata(Other.Metadata) {}
+
+  /// Add all metadata to \p I.
+  void applyMetadata(Instruction &I) const;
+
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ayalz wrote:

The newly introduced `addMetadata()` method deserves documenting, albeit trivial.

https://github.com/llvm/llvm-project/pull/143035