CFLAGS doco

[danielv]

Clarification: doco = documentation

 

http://www.funtoo.org/News:The_Many_Builds_of_Funtoo_Linux

takes us to ...

http://www.funtoo.org/Subarches

Let's say you have a core2_64 chip, so from the Subarches page you'd go to http://www.funtoo.org/Core2_64

 

See http://www.funtoo.org/Installation_%28Tutorial%29

 

edit /etc/make.conf

CHOST="x86_64-pc-linux-gnu"

 

CFLAGS="-march=core2 -O2 -pipe" <-- as per http://www.funtoo.org/Core2_64

CFLAGS="-march=native -O2 -pipe"  <-- as per http://www.funtoo.org/Installation_%28Tutorial%29

 

Which is the best CFLAG option to use?

Can we please edit the appropriate web page to be consistent?

 

Thanks! danielv

[Oleg Vinichenko]

a tutorial (a big messy page) never was a consistent page and wasn't actively checked (if at all) by stuff. -march=native is GCC optimization that used for a target cpu, i.e what gcc finds best. Many believe that gives more optimizied code and it is stable, it is widely used. My personal opinion: if it does any improvements, they are ngligible on recent hardware. other than that, how gcc calculates it? Likely there is internal test suite for a cpu instruction and cache parameters, which tell what to enable. However, it might be not perfect. It is up to user to decide.

[danielv]

Thanks, and how do you prefer to be addressed in the forums?

 

See

https://wiki.gentoo.org/wiki/CFLAGS

and

https://wiki.gentoo.org/wiki/Safe_CFLAGS

for more information.

 

danielv