Re: [gentoo-user] gcc 4.2 and Core 2 Duo

[Kenneth Prugh]

Andrew Gaydenko wrote:
> I have noticed, the official portage tree has included gcc 4.2. Now for
> Core 2 Duo CPU (amd64 Gentoo arch) I use in make.conf file:
>
> CFLAGS="-O2 -march=nocona -pipe"
>
> gcc' changelog has this note:
>
> --------------------
> ...
> IA-32/x86-64
>
>     * -mtune=generic can now be used to generate code running well on common x86 chips.
>       This includes AMD Athlon, AMD Opteron, Intel Pentium-M, Intel Pentium 4 and Intel
>       Core 2.
>     * -mtune=native and -march=native will produce code optimized for the host
>       architecture as detected using the cpuid instruction.
> ...
> --------------------
>
> The question is: must I replace '-march=nocona' with '-mtune=native and -march=native'?

I have a Core2 Duo E6600 and use these CFLAGS with GCC 4.2:

CFLAGS="-Os -march=native -mtune=native -fomit-frame-pointer -pipe -mmmx
-msse2 -msse3"

Native works fine here.
-- 
Kenneth Prugh - Ken69267
Gentoo AMD64 Arch Tester