SmallVector<ElementsAttr> inputs;
  for (auto operand : op->getOperands()) {
    auto preceding_const_op = operand.getDefiningOp<TF::ConstOp>();
    if (preceding_const_op) {
      inputs.push_back(preceding_const_op.getValue());
      continue;
    }

    Operation* preceding_op = operand.getDefiningOp();
    int preceding_result_id = -1;
    for (auto preceding_result : preceding_op->getResults()) {

// See the function doc in the header file.
def GetPadOpType : NativeCodeCall<
  "GetPadOpType((*$0.begin()).getDefiningOp<mhlo::CompositeOp>())">;

// See the function doc in the header file.
def GetAvgPoolOpPadAttr: 
  NativeCodeCall<"GetAvgPoolOpPadAttr($_builder, (*$0.begin()).getDefiningOp<mhlo::CompositeOp>())">;

// Returns true if the provided padding in the composite op can *not* be 

bool NotFromDequant(mlir::Value value) {
  auto dequant_op = value.getDefiningOp<DequantizeOp>();
  if (dequant_op) {
    return false;
  }
  auto split_op = value.getDefiningOp<SplitOp>();
  if (!split_op) {
    return true;
  }
  return !split_op.getValue().getDefiningOp<DequantizeOp>();
}

// Optimize TFLite operations in functions.
class OptimizeBatchMatmulPass

  LogicalResult matchAndRewrite(TF::LookupTableFindV2Op find_op,
                                PatternRewriter& rewriter) const override {
    auto handle_op = find_op.getTableHandle().getDefiningOp();
    if (handle_op == nullptr) return failure();
    auto hashtable_op = llvm::dyn_cast<TFL::HashtableOp>(handle_op);
    if (hashtable_op == nullptr) return failure();
    rewriter.replaceOpWithNewOp<TFL::HashtableFindOp>(

    // * the arg to the identity op is produced by a TPUExecuteOp.
    if (op_device && op_device.getValue().contains("TPU")) {
      return true;
    }

    Operation *def_op = arg.getDefiningOp();
    // If the arg to this identity op is the arg of a function, there's no
    // defining op.
    if (def_op != nullptr &&
        (isa<TF::TPUExecuteOp, TF::TPUExecuteAndUpdateVariablesOp>(def_op))) {

      ResourceConstructingOps result(global_tensor);
      return result;
    }
  } else if (auto vh = dyn_cast<TF::VarHandleOp>(value.getDefiningOp())) {
    return ResourceConstructingOps(vh);
  } else if (auto it = dyn_cast<TF::IteratorOp>(value.getDefiningOp())) {
    return ResourceConstructingOps(it);
  }
  return ResourceConstructingOps();
}

ResourceConstructingOps ResourceConstructingOps::join(

  }

  if (v.getDefiningOp()->getNumOperands() == 1) {
    // If the value is originating from an unary op, assume it's something
    // simple like "cast" and keep tracing.
    return traceUpwardsToArgument(v.getDefiningOp()->getOperand(0), seen, out);
  } else {
    // Typically a tf.VarHandle op.
    return v.getDefiningOp()->emitOpError("Non constant predecessor");
  }
}

  static std::optional<FoldAdaptor> Create(Operation* operation) {
    auto foldable_opr = [](Value val) -> bool {
      return !llvm::isa<BlockArgument>(val) &&
             llvm::isa<stablehlo::ConstantOp>(val.getDefiningOp());
    };
    if (!llvm::all_of(operation->getOperands(), foldable_opr)) {
      return std::nullopt;
    }
    return FoldAdaptor(operation);
  }

def CloneF32ElementsAttrWithOnes
  : NativeCodeCall<"DenseElementsAttr::get($0.getType().cast<ShapedType>(), (float)1.0)">;

def NotConstant : Constraint<
    CPred<"$0.isa<BlockArgument>() || !llvm::isa<stablehlo::ConstantOp>($0.getDefiningOp())">,
    "Is not a constant.">;

def : Pat<(StableHLO_DivOp $l,
            (StableHLO_ConstantOp:$divisor FloatElementsAttr<32>:$cst)),
          (StableHLO_MulOp $l,
            (StableHLO_DivOp

  Operation* xla_call_module_op =
      FindOperationOfType<TF::XlaCallModuleOp>(main_fn);
  Operation* filter_dcast_op =
      xla_call_module_op->getOperand(1).getDefiningOp();
  Operation* filter_qcast_op = filter_dcast_op->getOperand(0).getDefiningOp();
  ASSERT_NE(filter_qcast_op, nullptr);
  EXPECT_TRUE(isa<quantfork::QuantizeCastOp>(filter_qcast_op));
  EXPECT_TRUE(isa<quantfork::DequantizeCastOp>(filter_dcast_op));