There is at least a third one:

"conditional indirect call". Now say "eek" :-)

Basically:

#if MORE_THAN_ONE_FUNCTION_NEEDED
extern func_t *theindirect;
#define thefunc(thepars) (*theindirect)(thepars)
#else
#define thefunc(thepars) __CONCAT(thefunc,ONLY_ONE_NEEDED)
#endif

Defining ONLY_ONE_NEEDED and MORE_THAN_ONE_FUNCTION_NEEDED in terms of the 
needed CPU's is left as exercise to the reader.

Regards,
	Ignatios Souvatzis