A little gem* from Apple’s WWDC “Platform State of the Union” session, introduced by Andreas Wendker:
We’re also working on a new technology that is very [much] forward-looking. We’re introducing Bitcode into the app submission process.
Bitcode […] allows the store to re-optimize your apps for each kind of device before they get delivered to the user. […] The store will be in a position to constantly re apply the latest compiler optimizations that we’ve been working on. It also future proofs your apps, because it will allow the store to take advantage of new processor capabilities we might be adding in the future, and all that without you having to resubmit your apps to the store.
This is a strong hint that a future iPad may run on a different processor (e.g., an Intel CPU on the rumored iPad Pro). Or that a future Mac might use an ARM CPU. See this interesting view by “Inertial Lemon“, on Medium.
Curiously, using Bitcode is mandatory on Apple Watch’s watchOS. So then, why might Apple Watch apps ever need to target a new CPU? The most likely reason is that Apple might want to adjust the CPU architecture. “Inertial Lemon” speculates that possibility:
In all likelihood, the S1’s CPU is pretty crappy. [In the sense that it’s a first-version of this CPU.] […]
Imagine that the chip designers know they can make the [Apple Watch’s CPU] S2 leaps and bounds better, but doing so would require making some design changes radical enough that they broke existing software. Should Apple go the iPhone 1.0 route and hold back the SDK for another hardware generation, leaving third party developers in the cold? Could Apple get away with breaking the entire first generation of apps and forcing developers to resubmit to be compatible with the next generation of the Watch? What if there were some magical third option that didn’t have any real downsides?
That third option, Inertial Lemon surmises, is Bitcode.
*Thanks to Dan Moren for citing it and for Leo Laporte for emphasizing its importance, on Leo’s MacBreak Weekly. Highly recommended.
Update 3 (July 17): I removed reference to John Siracusa’s Tweet and perspective on ARM, specifically because I think Inertial Lemon’s view is more detailed and offers a broader framing. I also extended the excerpt from Inertial Lemon. Don’t read into this: John is one of my favorite thinkers and podcasters. Details on updates 1 and 2, along with the original post, are here: OLD-Apple’s Bitcode Technology Hints at the Future [updated 2X].