gcc: which processoroptimization to use for AMD Duron

I have a rather old (non-portable) computer with a 900MHz AMD Duron processor. I want to optimize my system as much as possible for that processor, but am a bit puzzled by what I should specify as argument for '--march'.

I'm using -- and in the process of re-installing -- Gentoo.

I've used '--march=athlon-xp' before and that seemed to work flawlessly at first... but lately I've run into problems when I'm trying to generate info-pages... as well as with some packages (like 'texinfo).

I was pointed to the following bug, which seems to cover by problems:

Yesterday I tried '--march=athlon', and had a package fail during configuration becuase the c++ pre-processor (cpp) failed some test. Now, this *may* be because of other causes (I can honestly say I didn't pay close enough attention to the process to be sure I even USE-flags -- but for now, lets buttume '--march=athlon' won't work either.

According to the 'gcc' documentation, the choices -- apart from various iX86 (i386, i486,...) and various pentium-related -- are: Quote:

Which one(s) ought to best suited for Duron?

Also, buttuming I can't get '--march' to work... should I try '--mcpu'? AFAI understand, this option also optimize for specific processor, but without breaking compability with other x86-processors...

Although I can't get "athlon-xp" and "athlon" to work with '--march', is it possible to get them to work with '--mcpu' (I buttume '--mcpu' is less "hardline") ? Should I try specifying another type than those two for '--mcpu' ?

-Koppe