A shame operating systems like iOS/iPadOS do not allow JIT. iPad Pro's have such fast CPU's that you cant even use fully because of decisions like this.
They allow, but Apple's policy is to lock down that ability pretty much just to Safari/WKWebView. If you could transpile/compile your program to JS or WASM and run it through one of these blessed options, it should get JIT'ted.
They do, technically, allow JIT. You need a very hard-to-obtain entitlement that lets you turn writable pages into executable read-only pages, and good luck getting that entitlement if (for some reason) your name isn’t “mobilesafari”, but the capability exists.
When you say it's "hard" to obtain--is it possible to obtain if you aren't Apple? Does Apple ever provide it to third party developers, or is there even a path to requesting it?
JIT compilation can be faster for compiled languages too, as it allows data driven inlining and devirtualization, as well as "effective constant" propogation and runtime architecture feature detection
To re-optimize compiled code blocks isn't without effort. Google has publicly spoken about AutoFDO and Propeller [0], after Meta had open sourced BOLT [1] in 2021.
AutoFDO has since been ported to Android and adopted by Yandex [3].
Hard disagree. Many newer game system emulators (32-bit and up) rely on JIT or "dynarecs" to get playable speeds, and they pretty much all use high performance compiled languages already. They often double the performance over their interpreter or more.
Sure, but the relevant comparison isn't between languages: it's between a state-of-the-art JIT implementation of one language and a likewise-state-of-the-art AOT implementation of the same language. Unfortunately there aren't many examples of this; most languages have a preferred implementation strategy that receives much more effort than the other one.
I get that, but what interpreted language do you want to write iOS apps in when there's Swift and Obj-C right there, with bespoke support and tooling from Apple?
And if you care about performance, why aren't you writing that code in native to begin with?
