[llvm] [VPlan] Add VPPhiAccessors to provide interface for phi recipes (NFC) (PR #129388)

[Florian Hahn via llvm-commits]

================
@@ -1085,6 +1085,62 @@ class VPIRInstruction : public VPRecipeBase {
   void extractLastLaneOfOperand(VPBuilder &Builder);
 };
 
+/// Helper type to provide functions to access incoming values and blocks for
+/// phi-like recipes. RecipeTy must be a sub-class of VPRecipeBase.
+template <typename RecipeTy> class VPPhiAccessors {
+  /// Return a VPRecipeBase* to the current object.
+  const VPRecipeBase *getAsRecipe() const {
+    return static_cast<const RecipeTy *>(this);
+  }
+
+public:
+  /// Returns the \p I th incoming VPValue.
+  VPValue *getIncomingValue(unsigned I) const {
----------------
fhahn wrote:

Updated, thanks

https://github.com/llvm/llvm-project/pull/129388