Re: PPC cflags

On Sun February 20 2005 07:41 pm, Cameron Blackwood wrote:
> It's at this stage that Id like to re-suggest that we consider
> collecting a table of cflags and put in in the install or ppc docs.
> Something like table with a sample line from /proc/cpuinfo and then
> the stable and risky CFLAGS settings.
>

You might check out:
http://gentoo-wiki.com/Safe_Cflags

You could start your own page, and start collecting the data.

>
> For my G5 (no bogomips entry?):
>   CFLAGS="-O2 -mcpu=G5 -pipe -maltivec -mabi=altivec -fno-strict-aliasing
> -mpowerpc-gfxopt -mmultiple -mstring"
>
>
> For my 800Mhz G3 laptop (1589.24 bogomips by the way:):
>   CFLAGS="-O2 -pipe -mcpu=750 -mpowerpc-gfxopt -mmultiple -mstring"
>
>
>
> A while ago I was md5sum'ing some iso images and I noticed my G5
> was _WAY_ slower than my G3 laptop and it was because Id dropped
> the mcpu=G5 setting from my G5 CFLAGS. I realise that md5sum'ing is a
> special case, but small changes can make a massive change.
>
> Even if the idea is too hard for gentoo as a whole, would it be
> possible for gentoo-ppc?
>
>
> Ive suggested it a few times in posts like:
>
>   http://forums.gentoo.org/viewtopic-t-166999-highlight-.html
>
> but everyone seems to say that its too hard :-/ or that there are too
> many combos to track (which I dont quite get, I mean gentoo runs on
> what, a couple of hundred cpu variations? Wouldnt the pain that this
> solves be worth it? :)
>
> I mean developers and iso releasers must work this stuff out.... :)
> But I guess it would be harder in that one would need to collect the info
> for cpu model and gcc version or maybe 'gentoo/portage version' too.
>
> Id comment that once we had the data, creating a script on the install
> disk wouldnt be hard, but Im sure that would take away a little more
> of the 'hacker' spirit of the whole install process :-)
>
>
> cheers,
> cam
>
> --
>  / `Rev Dr'   cam  at darkqueen.org            Roleplaying, virtual goth \
> <   http://darkqueen.org        Poly, *nix, Python, C/C++, genetics, ATM  >
>  \  [+61 3] 9809 1523[h]         skeptic, Evil GM(tm). Sysadmin for hire /
>                       ---------- Random Quote ----------
> Don't kiss an elephant on the lips today.
>
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-- 
*******************************************
Dr. Erik Zeek
Postdoctoral Research Associate
Department of Physics and Astronomy
The University of Georgia
Athens, GA 30602-2451

Tel: 706-542-7293
Email: mailto:[email protected]
Html:  http://www.physast.uga.edu/~zeekec
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Against stupidity the very gods
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