Stata The Stata listserver
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

Re: st: Macs and 64-bit Memory Addressing

From   Michael Ingre <[email protected]>
To   <[email protected]>
Subject   Re: st: Macs and 64-bit Memory Addressing
Date   Sat, 01 Nov 2003 00:31:02 +0100

Den 03-10-31 18.19, skrev "[email protected]" <[email protected]>:

> Power Mac G5
> ------------
> "Use XCode to develop next-generation 64-bit applications. Use a Power Mac G5
> to compile 64-bit applications faster. XCode features gcc 3.3, and distributed
> builds over Rendezvous."
> So what do they mean by "64-bit application"?  The documentation I've seen for
> gcc 3.3 adds G5 optimization and some wide data type (forgot what kind) but no
> mention of 64-bit addressing.  If this is what they mean by a 64-bit
> application, then it's very misleading.  I know OS X is a 32-bit OS so
> Apple's definition of a 64-bit application seems to be different from my
> definition of a 64-bit application.  If their definition is the same, then
> there is some minimal support in OS X and that's what I was trying to find
> documentation on.

I guess that a 64 bit application could run under a partially 32-bit OS
(wasn't that the fact with Windows in the early days - 32 bit apps under a
mainly 16 bit OS?).

According to apple it is possible right now to gain a lot of speed in
calculations with 64 bit integers and floats (like Stata does a lot) quite
easy - if you use gcc 3.3.

This is what I found at apple.

About increased performance:

"64-bit-wide registers, data paths, and internal logic units make it
possible for the PowerPC G5 processor to do 64-bit-wide integer and
floating-point operations in one clock cycle.

"Among its 64-bit wide internal logic units are two 64-bit floating-point
units, two 64-bit integer units, and two 64-bit load/store units."

And this is how to:

" By writing the appropriate code, you can maximize your software's use of
the G5 processor's dual 64-bit floating-point units (FPUs), dual 64-bit
integer units, and dual load/store units. "

With this compiler flags:

In combination with the above flags, this flag tells the compiler to enable
the G5's native 64-bit long long support for greatly enhanced performance
when working with long longs."

Plus others like this:

In combination with the above flags, this flag tells the compiler to enable
the G5's hardware floating point square root support for greatly enhanced

*   For searches and help try:

© Copyright 1996–2024 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index