Right. That's what I figured. But a lot of people seem to go on about how -O6
should be used for best performace... I've found that somewhat confusing...
> > of -O2 (I compiled X without it and it's working fine. Hasn't crashed) or
> > is it something the kernel needs? And, what exactly does this do? I've read
> > the manpage but what that has doesn't mean much to me. I wish there was
> > info on not just what an optimisation flag does but also how it might effect
> > performance and what sideeffects it might have. (this is probably real hard
> > to do but it would be way useful. I don't mind long compile times as long
> > as runtime performance is imporved)
> >From the gcc manual:
>
> `-fomit-frame-pointer'
> Don't keep the frame pointer in a register for functions that
> don't need one. This avoids the instructions to save, set up and
> restore frame pointers; it also makes an extra register available
> in many functions. *It also makes debugging impossible on some
> machines.*
>
> This option is never turned on by default (on i386), so the kernel Makefile
> turns it on.
Uhuh. Does this prevent the use of gdb on the executable and can it be
used safely on libraries?
> Obviously, it should improve run-time performance, unless the gcc code
> optimizer is so buggy that it generates faster code with less registers
> available ;)
Hehe :)
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