On Sun December 4 2005 4:11 am, Kristian Poul Herkild wrote:
> Dale wrote:
> > Hi,
> >
> > I have been up and running a while and am running stable but this is
> > Gentoo. ;) I found a script that tells you what your CFLAGS are
> > suposed to be and it is different from what I am using. This is what I
> >
> > am using now, from make.conf of course:
> >>CFLAGS="-march=athlon-xp -O3 -pipe -fomit-frame-pointer"
> >
> > This is what the script said:
> >>-march=athlon-xp -mfpmath=sse -msse -mmmx -m3dnow
> >
> > I assume I would have to add the-O3 to that though.
> >
> > I have a AMD XP 2500+ and 1GB of ram. I like it to run fast even if it
> > takes longer to compile. I think that is where the -O3 comes in but be
> > gentle if I am wrong. For those who may read this and not tell the
> > difference, that is a minus sign, the letter O and the number three.
> >
> > What do you folks think? Is the one I am using better or the one it
> > says? I do have long uptimes so I do want to stay stable. I have went
> > as long as 9 months with no reboot.
> >
> > Thanks.
> >
> > Dale
> >
> > :-)
>
> Well, it looks pretty much like my CLAFGS:
>
> CFLAGS="-O2 -march=athlon-xp -mfpmath=sse -fomit-frame-pointer -msse
> -mmmx -m3dnow -pipe" (the same I used with LFS).
>
> The difference being -O2 instead of -O3.
>
> I don't think you'll gain much with the new CFLAGS, but they won't hurt
> stability.
>
> -Kristian Poul Herkild
-mfpmath=sse is not a good idea, the consensus is it actually lowers
performance. -msse -mmmx -m3dnow are redundant (implied by
-march=athlon-xp), and should be removed from your cflags line, but SHOULD be
placed in your USE= line, wthout the - sign, like this:
USE="mmx 3dnow sse"
If you use gcc-3.4.4, these flags should work fine (I've used them for a long
time- no problems).
CFLAGS="-march=athlon-xp -O3 -pipe -fomit-frame-pointer -fweb -ftracer
-fprefetch-loop-arrays -ffast-math -falign-functions=64 -fno-ident"
CXXFLAGS="${CFLAGS} -fvisibility-inlines-hidden"
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