mlir::OpBuilder op_builder(&module.getBodyRegion());
    module.walk([&](mlir::arith::ConstantOp const_op) {
      MaybeUnfoldLargeSplatConstant(&op_builder, const_op);
    });
  }

 private:
  void MaybeUnfoldLargeSplatConstant(mlir::OpBuilder* op_builder,
                                     mlir::arith::ConstantOp const_op) const {
    auto splat_elements_attr =

// This pattern checks if an i8 arith::ConstantOp tensor has all values within
// the INT4 range, i.e. [-8,7] and converts it into i4 if so. This assumes that
// the input is sign-extended two's complement.
class CheckRangeAndConvertI8ToI4 : public OpRewritePattern<arith::ConstantOp> {
 public:
  using OpRewritePattern<arith::ConstantOp>::OpRewritePattern;

  LogicalResult matchAndRewrite(arith::ConstantOp op,

    // Cannot use the pattern rewriter because the driver applies folders by
    // default.
    module.walk([&](mhlo::ConstantOp const_op) {
      UnfoldSplatConstant(&op_builder, const_op);
    });
  }

 private:
  void UnfoldSplatConstant(mlir::OpBuilder* op_builder,
                           mhlo::ConstantOp const_op) const {
    auto splat_elements_attr =
        mlir::dyn_cast<SplatElementsAttr>(const_op.getValue());

  auto attr = CreateTypedAttr(dense_type, value);

  return rewriter->create<arith::ConstantOp>(loc, dense_type,
                                             cast<TypedAttr>(*attr));
}

absl::StatusOr<arith::ConstantOp> CreateConstOpWithSingleValue(
    PatternRewriter* rewriter, Location loc, ShapedType shaped_type,
    int value) {
  ShapedType scalar_type =

      .replaceAllUsesWith(cloned_const_op->getResult(0));
}

bool IsConstOrQConstInt(Operation* op) {
  if (!llvm::isa<TFL::ConstOp, TFL::QConstOp, arith::ConstantOp>(op))
    return false;

  if (auto arith_const_op = dyn_cast_or_null<arith::ConstantOp>(op)) {
    // arith ConstOp path.
    auto type =
        mlir::cast<ShapedType>(arith_const_op.getType()).getElementType();

  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);
  }

        req_op.getLoc(), func_op.getResultTypes()[0], req_op.getOperand());
    if (func_name.contains("_relu6_")) {
      auto min = rewriter.create<mlir::stablehlo::ConstantOp>(
          req_op.getLoc(), rewriter.getF32FloatAttr(0));
      auto max = rewriter.create<mlir::stablehlo::ConstantOp>(
          req_op.getLoc(), rewriter.getF32FloatAttr(6));
      new_result = rewriter.create<mlir::stablehlo::ClampOp>(

  auto one_cst =
      rewriter.create<stablehlo::ConstantOp>(rewriter.getUnknownLoc(), one_val);

  auto half_val = DenseElementsAttr::get(type, kHalf);
  auto half_cst =
      rewriter.create<stablehlo::ConstantOp>(one_cst.getLoc(), half_val);

  auto one_over_root2_val = DenseElementsAttr::get(type, kOneOverRoot2);
  auto one_over_root2_cst = rewriter.create<stablehlo::ConstantOp>(
      half_cst.getLoc(), one_over_root2_val);

  LogicalResult match(mlir::stablehlo::TransposeOp op) const override {
    Value operand = op.getOperand();
    auto const_op =
        dyn_cast_or_null<mlir::stablehlo::ConstantOp>(operand.getDefiningOp());
    if (!const_op) return failure();

    // Only support float tensors.
    auto tensor_type = mlir::dyn_cast_or_null<TensorType>(const_op.getType());

namespace TFL {
namespace tac {

// Returns true if 'op' is non const op. Returns false otherwise or if
// 'op' is null.
inline bool IsNonConstOp(Operation* op) {
  if (!op) return false;
  if (llvm::isa<arith::ConstantOp, mlir::func::ConstantOp>(op)) return false;
  if (op->hasTrait<OpTrait::ConstantLike>()) return false;
  if (llvm::isa<TFL::ConstOp, TFL::QConstOp>(op)) return false;
  return true;
}