OSX Architecture related

0
votes

I am developing an application for Mac 10.7 and above (10.7, 10.8, and 10.9 for now). Based on my search on web -

  1. OSX 10.8 and 10.9 only comes with 64bit flavour
  2. OSX 10.7 supports both 32bit and 64bit Intel.
  3. IN OSX 10.7 - If I develop for 64bit(x86_64) then application will work in 32bit as well. https://discussions.apple.com/thread/3200553. In this case, How ARC handled internally?

Can someone please validate and confirm my assumptions above?

Thanks

2
macoscocoa

2 Answers

2
votes

x86_64 is not emulated on 32 bit machines, so if you want your code to work on those, you'll have to build for it. The discussion you're linking to discusses kernel architecture, which is irrelevant for your purposes.

ARC does not work in 32 bit code, so if you want to support 32 bit machines, you cannot build with ARC (and yes, like many such tradeoffs, choosing to support the older alternative adds work and is potentially error prone).

0
votes

Your best bet is to check the release notes. But if you try to compile for 32bit with a target SDK that doesn't support it Xcode will loudly tell you.

The last sold 32bit Macs were years ago. I'm but sure the hardware is even supported now. You will benefit greatly from targeting 64bit only and the latest release possible. With the new strategy to make updates free, it keeps things simple.