// Note: we do not use NodeBuilder or NodeDefBuilder as that would require
  // mapping back from the inputs to the input arguments.

  llvm::SmallString<64> op_name;
  if (IsLegacyCallInstruction(inst)) {
    // The op_name is the name of the function.
    op_name.append(inst->getAttrOfType<mlir::SymbolRefAttr>("f")
                       .getLeafReference()
                       .getValue());

        // TODO(prakalps): If two functions have cyclic dependence, this will
        // introduce an infinite loop.
        TF_RETURN_IF_ERROR(convert_called_function(op_name.value().str()));
      }

      if (IsLegacyCallInstruction(&inner_op)) {
        TF_RETURN_IF_ERROR(convert_called_function(
            inner_op.getAttrOfType<mlir::SymbolRefAttr>("f")
                .getLeafReference()
                .getValue()));
      }

        // TODO(prakalps): If two functions have cyclic dependence, this will
        // introduce an infinite loop.
        TF_RETURN_IF_ERROR(convert_called_function(op_name.value().str()));
      }

      if (IsLegacyCallInstruction(&inner_op)) {
        TF_RETURN_IF_ERROR(convert_called_function(
            inner_op.getAttrOfType<mlir::SymbolRefAttr>("f")
                .getLeafReference()
                .getValue()));
      }