Compiler Flags problem with core2 CPU
Paul B Mahol
onemda at gmail.com
Sun Feb 28 14:40:15 UTC 2010
Do not top post.
On 2/28/10, Aaron Lewis <aaron.lewis1989 at gmail.com> wrote:
> Really ? It's bad to use custom flags to compile kernel , why do you
> think so ?
> I'd like to know more about this : )
> So setting optimize compiler flags is only useful for userland stuff ?
> Paul B Mahol wrote:
>> On 2/28/10, Aaron Lewis <aaron.lewis1989 at gmail.com> wrote:
>>> I gonna recompile kernel for my core2 CPU , so i'd like to pass some
>>> flags to gcc.
>>> Kinds of "-march=core2" , i tried to modify /etc/make.conf
>>> e.g CFLAGS += -march=core2 -O20 -ffast-math -mfpmath=sse
>>> But it fails .. bad arch switch , core2 cpu is not supported ?
>> It is bad idea to compile kernel with custom flags. And gcc in FreeBSD
>> doesn't know about core2,
>> use 'native' if you must.
>>> And is that useful to let gcc select cpu specified asm code ?
>> Only for some userland stuff like openssl.
> Best Regards,
> Aaron Lewis - PGP: 0xA476D2E9
> irc: A4r0n on freenode
More information about the freebsd-questions