// Current supported ops between convolution input and the block arguments are
// PadOp and CastOp.
std::optional<BlockArgumentInfo> GetInputBlockArgNum(Value input) {
  auto block_arg_num = GetBlockArgNum(input);
  if (block_arg_num.has_value()) return block_arg_num;

  Value next_input = input;
  auto pad_op = dyn_cast_or_null<TF::PadOp>(next_input.getDefiningOp());

    return rewriter.notifyMatchFailure(
        stb_op, "result for current op has more than 1 use");
  }

  // Pad op.
  TF::PadOp pad_op;
  ElementsAttr pad_attr;
  if (llvm::isa<TF::PadOp>(consumer_op)) {
    pad_op = llvm::cast<TF::PadOp>(consumer_op);
    if (!pad_op.getResult().hasOneUse()) {
      return rewriter.notifyMatchFailure(
          pad_op, "result for current op has more than 1 use");

//  %y1 = pad(%x, pad_val, (p1_1,p1_2,p1_3, ...))
//  %y2 = pad(%y1, pad_val, (p2_1,p2_2,p2_3, ...))
// To:
//  %z = pad(%x, pad_val, (p1_1 + p2_1, p1_2 + p2_2, p1_3 + p2_3, ...))
LogicalResult MergeConsecutivePad(mhlo::PadOp pad_op,
                                  PatternRewriter &rewriter) {
  // Fail for non-static shapes
  if (!pad_op.getOperand().getType().hasStaticShape() ||
      !pad_op.getResult().getType().hasStaticShape() ||

          TF::MaximumOp::getOperationName().str(),
          TF::MeanOp::getOperationName().str(),
          TF::MinimumOp::getOperationName().str(),
          TF::MulOp::getOperationName().str(),
          TF::PadOp::getOperationName().str(),
          TF::PadV2Op::getOperationName().str(),
          TF::Relu6Op::getOperationName().str(),
          TF::ReluOp::getOperationName().str(),
          TF::ReshapeOp::getOperationName().str(),

      // $max_output_size
      CompileTimeConstantOperand<TF::NonMaxSuppressionV4Op, 2>,
      CompileTimeConstantOperand<TF::OneHotOp, 1>,  // $depth
      CompileTimeConstantOperand<TF::PadOp, 1>,     // $paddings
      CompileTimeConstantOperand<TF::PadV2Op, 1>,   // $paddings
      // $shape
      CompileTimeConstantOperand<TF::ParameterizedTruncatedNormalOp, 0>,

        TypeID::get<TF::NegOp>(),
        TypeID::get<TF::NextAfterOp>(),
        TypeID::get<TF::NonMaxSuppressionV4Op>(),
        TypeID::get<TF::NotEqualOp>(),
        TypeID::get<TF::PadOp>(),
        TypeID::get<TF::ParameterizedTruncatedNormalOp>(),
        TypeID::get<TF::PlaceholderWithDefaultOp>(),
        TypeID::get<TF::PolygammaOp>(),
        TypeID::get<TF::PopulationCountOp>(),