Compiler Flags problem with core2 CPU
aaron.lewis1989 at gmail.com
Sun Feb 28 14:37:40 UTC 2010
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.
Aaron Lewis - PGP: 0xA476D2E9
irc: A4r0n on freenode
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