[llvm] [VPlan] Introduce VPScalarPHIRecipe, use for can & EVL IV codegen (NFC). (PR #114305)

[via llvm-commits]

================
@@ -3478,20 +3471,30 @@ void VPActiveLaneMaskPHIRecipe::print(raw_ostream &O, const Twine &Indent,
 }
 #endif
 
-void VPEVLBasedIVPHIRecipe::execute(VPTransformState &State) {
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+void VPEVLBasedIVPHIRecipe::print(raw_ostream &O, const Twine &Indent,
+                                  VPSlotTracker &SlotTracker) const {
+  O << Indent << "EXPLICIT-VECTOR-LENGTH-BASED-IV-PHI ";
+
+  printAsOperand(O, SlotTracker);
+  O << " = phi ";
+  printOperands(O, SlotTracker);
+}
+#endif
+
+void VPScalarPHIRecipe::execute(VPTransformState &State) {
   BasicBlock *VectorPH = State.CFG.getPreheaderBBFor(this);
   Value *Start = State.get(getOperand(0), VPLane(0));
----------------
ayalz wrote:

Better use getStartValue() than getOperand(0).

https://github.com/llvm/llvm-project/pull/114305