Data packers having corresponding methods and tangible computer-readable media comprise: a controller configured to receive output information, wherein the output information specifies an output alignment; a first multiplexer configured to pass one of data received into the data packer, and data stored in a register of the data packer; a rotate shifter configured to rotate-shift, in accordance with the output alignment, data passed by the first multiplexer; a second multiplexer configured to pass at least one of the data output by the rotate shifter, and the data stored in the register.