Thorsten wrote:
> You need to know the background to understand the answer.  That is given on
> the Apple developer page.  You certainly won't find Apple holding your hand
> and saying: Do not use -mpowerpc64 when compiling POV-Ray because [...]. ;-)

Thorsten, do you have a link to the developer page you mentioned?
I would like to know more about this.
Till now, I mostly get answers like "you are unexperienced...,it shows that
you are...,better do not compile...,"

I make a suggestion:
Could you please communicate in a more constructive way and tell me
references to qualified technical documentation proofing what you are
saying?

Most of the documentation I've consulted so far, recommends/suggests the use
of -fast or -mpowerpc64 for optimization.

And here is the reference from Apple:
http://developer.apple.com/technotes/tn/tn2086.html
http://developer.apple.com/technotes/tn/tn2087.html

What I can say for now is:
-fast does not work! It turns on a combination of optimization flags which
results in simply non working code. I wonder because -fast was intended to
boost performance on the G5. I think it is a gcc bug. Everything which is
not working as described in the documentation I consider as a bug.

-mpowerpc64 can be used (for POVray as well) with most of the optimization
flags. I've worked out a combination of optimization flags (including
mpowerpc64) on the G5 which results in a 10% performance gain compared to
the standard build which is optimized for the G4. That's not a big deal,
but I think it is worth to do it.

Others have made similar experiences according -fast/mpowerpc64
see http://www.math.colostate.edu/~hulpke/osx/

Post a reply to this message