Parameter vs macros to control which function is called
Something like:

`ifndef AES_256 // expanding a 128- or 192-bit key
`define theExpandBlock expandBlock_long
`else // Expanding a 256-bit key
`define theExpandBlock expandBlock_short
`endif // `ifndef AES_256

...
expandedKey.expBlocks[i] = `theExpandBlock(...
...


perhaps?