Re: [gentoo-user] CFlags for CPU

[Mark Knecht <markknecht@gmail.com>]

On Tue, Jul 26, 2011 at 1:36 PM, Alokat <mailing@alokat.org> wrote:
> Hi folks,
>
> I'm wondering what kind of cpu-type I should use?
>
> cat /proc/cpuinfo
> ..............
>
> processor       : 1
> vendor_id       : GenuineIntel
> cpu family      : 6
> model           : 15
> model name      : Intel(R) Core(TM)2 Duo CPU     L7100  @ 1.20GHz
> stepping        : 11
> cpu MHz         : 1197.065
> cache size      : 4096 KB
> physical id     : 0
> siblings        : 2
> core id         : 1
> cpu cores       : 2
> apicid          : 1
> initial apicid  : 1
> fpu             : yes
> fpu_exception   : yes
> cpuid level     : 10
> wp              : yes
> flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca
> cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm
> constant_tsc arch_perfmon pebs bts rep_good nopl aperfmperf pni dtes64
> monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm ida dts tpr_shadow
> vnmi flexpriority
> bogomips        : 2394.01
> clflush size    : 64
> cache_alignment : 64
> address sizes   : 36 bits physical, 48 bits virtual
> power management:
>
> ..............
>
> After a short research on this website:
> http://gcc.gnu.org/onlinedocs/gcc-4.6.1/gcc/i386-and-x86_002d64-Options.html#i386-and-x86_002d64-Options
>
> I guess core2 is the right one?
> Is that true?
>
> Regards,
> alokat
>

Or let gcc figure it out using

-march=native

which is what I eventually did:

# Please consult /usr/share/portage/config/make.conf.example for a more
# detailed example.
CFLAGS="-O2 -march=native -pipe"
#Safe CFlags for the Core-i7 (web info) saved for reference
#CFLAGS="-march=core2 -msse4 -mcx16 -msahf -O2 -pipe"
CXXFLAGS="${CFLAGS}"
# WARNING: Changing your CHOST is not something that should be done lightly.
# Please consult http://www.gentoo.org/doc/en/change-chost.xml before changing.
CHOST="x86_64-pc-linux-gnu"


HTH,
Mark