[RISCV] Simplify calling use_empty()

[benshi001]

Summary

The check of the possible dead node can be performed via SDValue::use_empty() instead of SDNode::use_empty().

[benshi001]

Sorry, it is my mistake. Please close this review request.

[MaskRay]

The API is actually different: SDNode::use_empty checks uses while SDValue::use_empty only checks uses of the return value. The former is more efficient. I think it is possible that SDValue::use_empty can be used instead but I am not sure this entails a change.

You can click "Add Action..." and then abandon the differential revision.

llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp

while (Position != CurDAG->allnodes_begin()) {
     if (BaseOpIdx == 0) // Load
       CurDAG->UpdateNodeOperands(N, Base.getOperand(0), ImmOperand,
                                  N->getOperand(2));
     else // Store
       CurDAG->UpdateNodeOperands(N, N->getOperand(0), Base.getOperand(0),
                                  ImmOperand, N->getOperand(3));
 
     // The add-immediate may now be dead, in which case remove it.
-    if (Base.getNode()->use_empty())
+    if (Base.use_empty())
       CurDAG->RemoveDeadNode(Base.getNode());
   }
 }
 
 // This pass converts a legalized DAG into a RISCV-specific DAG, ready
 // for instruction scheduling.
 FunctionPass *llvm::createRISCVISelDag(RISCVTargetMachine &TM) {
   return new RISCVDAGToDAGISel(TM);
 }