Warren Togami (wtogami(a)redhat.com) said:
This is a silly notion. Atom requires code to be built entirely
differently from all modern processors in order to get maximum
performance. Code must be optimized for in-line performance. Atom
target support hasn't even hit gcc-4.4 yet.
Interestingly, using the parts of OpenBench that can actually be
cajoled to build and run correctly (why are benchmark suites such
pain?)... the best option for atom is -march=i686 -mtune=generic.
Tuning for i586 (the previous in-order processor) doesn't actually
help.
Also, -march=i686 was a win over -march=i586, in general, in testing
across Atom, Core2Duo, and a Athlon64, although not a particularly
significant one.
Bill