http://gentoo-wiki.com/Safe_Cflags
> Intel Core 2 Duo/Quad / Xeon 51xx/53xx
>
> vendor_id : GenuineIntel
> cpu family : 6
> model : 15
> model name : Intel(R) Core(TM)2 CPU XXXX @ XXXGHz
>
> *32 bit profile (x86)*
>
> CHOST="i686-pc-linux-gnu"
> CFLAGS="-march=prescott -O2 -pipe -fomit-frame-pointer"
> CXXFLAGS="${CFLAGS}"
>
> *64 bit profile (amd64)*
>
> CHOST="x86_64-pc-linux-gnu"
> CFLAGS="-march=nocona -O2 -pipe"
> CXXFLAGS="${CFLAGS}"
>
> *Note:*
>
> - GCC 4.3 has
> -march=core2[1]<http://www.gnu.org/software/gcc/gcc-4.3/changes.html>,
> but Gentoo has nothing above 4.2 in portage.
>
>
