processor type and architecture optimizations

[Daniel Borgmann <danny@liebesgedichte.net>]

hello!

i want to compile optimized binarys.
so i was told to use "-O3 -mcpu=xxx -march=yyy"
where i have to replace xxx and yyy of course.
my question is, what values i have to use.
i got an athlon processor.
i *guess* it should be -mcpu=i686 -march=i368 but it's really just a wild 
guess i don't want to base my compilations on wild guesses ;)
i tried to find a general table on serveral linux document pages but couldn't 
find anything. i even couldn't find anything appropriate to my athlon (or 
pentium II compatible) cpu in the gcc man page (maybe i'm just blind).
can somebody tell me the exact values?
or does someone know a website where all possible architectures and cpu types 
are listed with their appropriate values?

- Daniel