Re: CPU optimization

[Zach Loafman <zml@zml.net>]

Jeronimo Pellegrini <pellegrini@mpcnet.com.br> writes:

> >> I also don't know if -O6 does the same thing as -O9.
> >> 
> >> []s, Roger...
> 
> > I've read something on a archive of a gcc mailing list but apparently it
> > doesn't relate to the gcc we use-don't remember the link ,I
> > researched this for a few hours.I got stuck at the debian/rules when
> > I decided to ask for help.
> 
> Yes... I saw a few Makefiles using -O9 and -O10.

You should never blindly use high optimization levels. For one, there
is nothing wired above -O3, so -O9 and -O10 both fall back to -O3,
IIRC. For another, -O2 is considered for many applications the
maximum safe optimization level, so recompiling all of your packages
with -O3 might not be the best idea. (I know I've had programs I've
written die on -O3 that work on -O2). -O2 is considered to be the
"production code where you don't care about length of compile time"
option.

-- 
Zachary M. Loafman