/// propagated to the callee.
          return isa<CallOpInterface>(caller) &&
                 std::equal(caller->getOperandTypes().begin(),
                            caller->getOperandTypes().end(),
                            callers.front()->getOperandTypes().begin());
        })) {
      if (llvm::any_of(callers, [](Operation* op) {
            return isa<IfOp, WhileOp, CaseOp>(op);
          }))

  // still.
  auto is_legal = [](Operation *op) {
    auto is_not_variant = [](Type ty) {
      return !ty.cast<ShapedType>().getElementType().isa<TF::VariantType>();
    };
    return llvm::all_of(op->getOperandTypes(), is_not_variant) &&
           llvm::all_of(op->getResultTypes(), is_not_variant);
  };

  auto is_set_item_legal = [](Operation *op) {
    return op->hasAttr("resize_if_index_out_of_bounds") &&

  const int kLargeElementsAttr = 16;
  std::string op_str;
  llvm::raw_string_ostream os(op_str);
  inst->getName().print(os);
  os << "(";
  if (!inst->getOperandTypes().empty()) {
    bool first = true;
    for (Type operand_type : inst->getOperandTypes()) {
      os << (!first ? ", " : "");
      first = false;
      os << operand_type;
    }
  }
  os << ") -> (";
  if (!inst->getResultTypes().empty()) {