Another thing they can do: it allows them to introduce new non-ARM-standard ops and immediately recompile the app store to take advantage of them.<p>Every now and then I see a new comparison of the Swift&#x2F;ObjC dispatch assembly.  Now imagine — that could be a single opcode.  Or the dispatch table could get pinned to a particular cache.  Or it could be other micro-optimizations that they are in a unique position to exploit with full control of the language, compiler and chip.<p>I have no idea how feasible these things might be or how much of a gain it would create, but they can look through their corpus of LLVM-IR and identify hot-spots where a new opcode would speed <i>everything</i> up by some margin.