On Aug 20, 2012, at 12:14 AM, Dale Miller <dalelmil...@comcast.net> wrote:
> On 8/12, John McCall wrote: 'In the so-called "fragile" ABI, which is what > you get on PPC, PPC64, and i386...". > PPC64's being included in this list surprised me, so I went to my docs (I'm > on 10.5.8 until they pry my G5 from my dead,cold hands). All the mentions I > can find of the fragile ABI explicitly describe it as inherent in a 32-bit > environment, and the non-fragile environment being supported in the 64-bit > environment, without any qualification as to PPC versus Intel. > while I'm at it, I have noticed several times mention being made of > "bugginess" in the PPC64 environment. I'm aware that converting a PPC > application to 64-bit might not improve performance because of the increased > size of pointers, etc, but this is really because the PPC (G5) does not > provide additional registers (already has 32 GPR's) and uses registers for > most parameter passing instead of having to put them in memory on the stack > even in 32-bit mode. So can anyone let me know specific problems so I can > avoid them? I have a personal use for a 64-bit application that I've been > thinking of writing and I don't want to run it on my 10.6 Macbook. > > Dale Miller Bitness has nothing to do with the modern ABI, really. The reason the modern ABI runs only on 64-bit on OS X is because 64-bit Intel was the latest and greatest architecture for OS X (and still is), and therefore was the architecture for which Apple decided to expend resources improving the ABI. It didn't hurt that there was next to no existing 64-bit OS X software at the time, so they didn't have to deal with any legacy software issues. On the iPhone, the modern ABI runs in 32-bit. Charles _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
