On 1/30/07, Christopher Barker <[EMAIL PROTECTED]> wrote: > Hi all, > > I had a question/comment from a numpy/Scipy developer that I was asked > to forward on: > > > > To get the "definition" of "universal" I went to > > > http://en.wikipedia.org/wiki/Universal_Binaries > > > > > > the last paragraph says: > > > Apple's Xcode 2.4 takes the concept of universal binaries even > > > further, by allowing four-architecture binaries to be created (32 and > > > 64 bit for both Intel and PowerPC), therefore allowing a single > > > executable to take full advantage of the CPU capabilities of any Mac > > > OS X machine > > What are folk's thoughts on building "quad binary" universal builds in > the future? Is there much point? Are there any 64bit Intel Macs? What > difference might a 64bit build make on a G5?
A 64-bit build would use more RAM, and it would let you address more RAM. That's pretty much it. It would also be only usable on leopard. I tried to build ppc64 on my G5 with tiger and it just crashed (and I didn't have enough reason to figure out exactly why). For intel it's probably a bit different because there's more registers and whatnot in 64-bit mode... so it may actually be an overall performance win for machines that can do it. I think all Core 2 Duo machines are x86-64 capable. > For the app in mind, this is the issue: > > I am interested in 64-bit because it is supposed to be able to > open >4GB data files in memmap mode (that is, you could treat any > large data set like a normal numpy array and *instantaneously* access > sub-data without ever loading the entire file. Note that this works > even with small amounts of physical memory, only the (theoretical) > memory address space has to be 64bit.) That is a good use case for having a 64-bit address space. The problem with a quad binary build is that there's a lot more difference between 32-bit and 64-bit than there is from PPC and Intel. It would be a lot of work to make that happen. It would also end up in pain because I believe that a 64-bit machine would default to using the 64-bit version of the executable which wouldn't be compatible with any existing extensions. It would make a lot of sense to have a 64-bit python distribution that was built for x86-64 and ppc64... but I don't think it would be a good idea to try and make python build quad. -bob _______________________________________________ Pythonmac-SIG maillist - Pythonmac-SIG@python.org http://mail.python.org/mailman/listinfo/pythonmac-sig
