How Single App Binary Supports 64-bit and 32-bit Apps

Question

We can see apple announcement here.. According to this doc, we can submit same binary with supporting 32-bit and also 64-bit. I found one stack overflow answer here. But Accordi

Answer 1

As for first part of question - Base SDK should be "Latest iOS SDK" which is iOS 7.0. Minimum deployment target should be iOS 6.0 or you won't be able to select "Standard architectues including 64-bit(armv7, armv7s, armv8)" for architectures. After you select these settings your app will be built for either 32 bit and 64 bit.

As for update - after switching to 32/64bit archs, analyze your project and fix new warnings that can appear. Then test your app on real 64 bit device(iPhone 5s/iPad Air/iPad mini retina). If your app uses iCloud, test synchronization between 32 and 64 bit devices. Helpful info is in Apple's guide (summary from there is in @iDev answer).

EDIT

Actually yes, minimum is 5.1.1, but you should either set it manually or set deployment target lower than 6.0 and when you select architectures to incl. 64bit Xcode will ask you to set it as 5.1.1. Anyway I'm not sure why you'd want to support 5.1.1 specifically if you want to use 64bit archs.