void MergeIfPerSegment(
    llvm::SmallVector<TF::IfRegionOp, 8>& if_op_segment,
    llvm::SmallVector<Operation*, 8>& moved_ops_list,
    llvm::SmallSetVector<TF::IfRegionOp, 8>& regions_to_remove,
    llvm::SmallDenseMap<Operation*, TF::IfRegionOp>& old_to_new_IfRegion_map) {
  TF::IfRegionOp first_if = if_op_segment[0];
  llvm::SmallVector<Type, 4> merged_return_types;
  llvm::SmallVector<TF::IfRegionOp, 8> sources_if_ops(

  builder.create<YieldOp>(loc, cond_block->getArgument(0));
}

// Create an IfRegionOp with a predicate from `optional_has_value`.  If true, it
// uses `get_next` to get the next value and calls `reduce_func`.  `body_args`
// is used as pass through of state values for else branch.  `dataset_types` is
// used for constructing the CallOp for `reduce_func`.
IfRegionOp CreateOptionalDatasetIf(

                       destination_block->getArguments());
}

/// Convert the `tf.IfRegion` op to the `scf.if` op.
class ConvertIfRegionOp : public OpRewritePattern<IfRegionOp> {
 public:
  using OpRewritePattern<IfRegionOp>::OpRewritePattern;

  LogicalResult matchAndRewrite(IfRegionOp op,
                                PatternRewriter& rewriter) const override {
    // Creates the `then` or `else` region of the `scf.if` op. Note that

  pm.addNestedPass<mlir::func::FuncOp>(
      mlir::TFDevice::CreateDecomposeResourceOpsPass());
  pm.addPass(mlir::TF::CreateNameAnonymousIteratorsPass());

  // This will add regions to IfOp/WhileOp (turning them into IfRegionOp
  // and WhileRegionOp), but be aware that those regions will still contain
  // calls.
  pm.addPass(mlir::TF::CreateTFFunctionalControlFlowToRegions());

  return to_bool;
}

// Transform a functional IfOp to a region based IfRegionOp.
LogicalResult ConvertIfOp(IfOp if_op) {
  Value cond = ConvertConditionToBoolean(if_op, if_op.getCond());
  OpBuilder builder(if_op);
  auto if_region = builder.create<TF::IfRegionOp>(
      if_op.getLoc(), if_op.getResultTypes(), cond, if_op.getIsStateless(),

class FoldConstantIfRegionOp : public OpRewritePattern<TF::IfRegionOp> {
 public:
  explicit FoldConstantIfRegionOp(MLIRContext* context)
      : OpRewritePattern<TF::IfRegionOp>(context) {}
  LogicalResult matchAndRewrite(TF::IfRegionOp op,
                                PatternRewriter& rewriter) const override;
};

LogicalResult FoldConstantIfRegionOp::matchAndRewrite(
    TF::IfRegionOp op, PatternRewriter& rewriter) const {

    callee_names = {first_call.value().getCallee(),
                    second_call.value().getCallee()};
  }
};

// Transform IfRegionOp to IfOp.
LogicalResult RegionControlFlowToFunctional::ConvertIfOp(
    SymbolTableCollection& symbol_table, IfRegionOp if_region) {
  llvm::SmallVector<Value, 4> extern_values;

  // For IfOp, arguments of calls in the then and else regions match if they

          /*device_ordinal=*/builder.getI64IntegerAttr(0), device_type_attr),
      builder);
}

// Clones an IfRegionOp 'if_region' and attributes and creates then/else regions
// with yield op and an empty block.
mlir::TF::IfRegionOp CloneEmptyIfWithPredicate(mlir::TF::IfRegionOp if_region,
                                               OpBuilder& builder) {

  return success();
}

// Returns true if the op contains a `CalibrationStatisticsSaverOp`.
bool ContainCalibrationStatisticsSaverOp(Operation* op) {
  // Check the region for CaseRegionOp, IfRegionOp and WhileRegionOp.
  for (Region& region : op->getRegions()) {
    if (!region.getOps<TF::CalibrationStatisticsSaverOp>().empty()) {
      return true;
    }
  }

        PropagatePotentiallyWrittenUpFromCallee(callee.getRegion(),
                                                if_op.getInput());
      }
      return;
    }
    if (auto if_op = dyn_cast<TF::IfRegionOp>(op)) {
      PropagatePotentiallyWrittenUpFromCallee(if_op.getThenBranch(),
                                              if_op.getODSOperands(1));
      PropagatePotentiallyWrittenUpFromCallee(if_op.getElseBranch(),