GCC check capabilities of platform and compare side-by-side:

gcc-compare.sh

# source: http://forums.gentoo.org/viewtopic-p-6242890.html

# diff --side-by-side <(gcc -Q --help=target -march=atom) <(gcc -Q --help=target -march=native)

# core2 and atom seem to be quite similar in capabilities, through probably
# not in tuning

-O2 \
-march=core2 \
-funswitch-loops \
-ftree-vectorize \
-fomit-frame-pointer \
-mfpmath=sse