8 way joysticks and mame

VERY odd question for the MAME knowing duders

Do 8 way joysticks register 8 separate inputs? Or is it combinations of the four?

Example: does it register down-right as being a separate input from down, right, and down-right? Or does it register it as Down + Right?

AFAIK the controls map to up/down/left/right by default, and diagonals are triggered via combinations of those four; at least, whenever I use MAME, this is how I configure my 8-way joystick. I think some MAME builds have mappings available for diagonal directions, but I'm not sure how those work or if they work with all games, as I've never actually tried them.

@cloudymusic: So generally just setting for d/r/l/u would be better than setups with 8 separate directions. That makes life MUCH easier. Thank you!