plans for 64bit support (Joshua Root)

[Joshua Root]

Emil Lundberg wrote:
>>> Is there documentation backing up the  
>>> claim
>>> that 64-bit ppc code is slower on 64-bit ppc machines than 32-bit  
>>> ppc code?
>> I've seen benchmark numbers that show this. I'll see if I can dig  
>> them up.

OK, I found some of the comparisons I was thinking of: a Linux-based one
with several benchmarks[1], and two Darwin-based ones using Geekbench,
on Tiger[2] and Leopard[3].

[1] <http://lixom.net/~olof/64bit-perf.pdf>
[2] <http://www.geekpatrol.ca/2006/09/32-bit-vs-64-bit-performance/>
[3]
<http://www.primatelabs.ca/blog/2007/10/leopard-performance-october-2007/>

I'll have access to a G5 in a few days' time, so if no one beats me to
it, I'll run some other comparisons.

> Thought I'd chip in. We use a wide array of hardware at our site; ppc  
> & x86, 32 and 64-bit. Some applications DO need the 64-bit binaries  
> (need to address 6+ Gb arrays), and the major hurdle in using 64-bit  
> is not in the apps themselves but in all the libraries that they use.
> 
>  From our perspective, it is more important to support building fat  
> 32/64-bit binaries than ppc/x86, as we do not generally share or sync  
> the macports file tree between machines (way too risky and servers  
> tend to be out of sync library- and OS-wise anyway). Thus a particular  
> machine does not require dual architetures but may require 32/64-bit  
> binaries/libraries, depending on the apps that use them. 

Your situation is fairly rare though, isn't it? It seems like a perfect
use case for variants.conf.

> Also, the  
> rest of the OS nowadays is quad-fat, so so should MacPorts, right... :-)

Well, no. The libraries are (mostly) 4-arch, but AFAICT none of the
actual programs (including command-line ones) that ship with Leopard
have 64-bit code, with the exception of XCode and Chess.

Cheers,
Josh