// Reshape input image to add a new spatial dimension.
    auto image_type = mlir::cast<ShapedType>(conv_op.getLhs().getType());
    SmallVector<int64_t, 4> image_2d_shape(image_type.getShape().begin(),
                                           image_type.getShape().end());
    image_2d_shape.push_back(1);
    auto image_2d_type =
        RankedTensorType::get(image_2d_shape, image_type.getElementType());
    auto loc = conv_op.getLoc();