3 ms·
> One cannot have writeable executable memory on iOS (apple can, we cannot). > Thus one cannot make a JIT compiler for js and thus pages are slow. Lack of JIT
by zzzcpan 7y ago
> One cannot have writeable executable memory on iOS (apple can, we cannot).
> Thus one cannot make a JIT compiler for js and thus pages are slow.
Lack of JIT doesn't slow down pages much. I believe the difference is so small that it might even be possible to be faster without JIT for most pages, especially on low power devices, it's only computation heavy pages that are going to suffer and even then it's not like you can't optimize common patterns statically ahead of time.
It doesn't mean that it's a good idea to invest into it, you are still under Apple's mercy and they clearly don't want competing browser engines.
- sharpneli 7y agoIf I have understood correctly (I’m a C++ graphics programmer. So don’t know too much about what’s flashy in the web world) V8 only jits. As in it can only produce machine code and there is not even an option to run it as an interpreter.
- saagarjha 7y agoV8 has a high performance, JIT-less interpreter that disables TurboFan and relies exclusively on Ignition: https://v8.dev/blog/jitless https://v8.dev/blog/jitless
- chrisseaton 7y ago> Lack of JIT doesn't slow down pages much. So why do you think so many major companies invest such a huge amount of money in JS JITs? Google, Apple, Microsoft, Oracle, Mozilla all maintain JS JITs and spend what I guess is hundreds of millions of dollars a year on it.
- notacoward 7y agoA budget of $100M, with 50% devoted to salary and a median salary of $250K, would be 200 developers. I seriously doubt any of the companies you name are devoting even a quarter of that to JS JIT development. Yes, they each make significant investments, but let's not weaken the argument by indulging a penchant for hyperbole.
- chrisseaton 7y agoAbout 200 seems about right to me across all these companies. Have you worked on one of these teams? > let's not weaken the argument by indulging a penchant for hyperbole Please don’t be so dismissive and snide - there’s no need for that.
- notacoward 7y ago> About 200 seems about right to me across all these companies. Then your initial estimate was way off, because you were suggesting multiple hundreds of millions and the average salary probably isn't that high. > there’s no need for that Honest argument wouldn't require such forceful correction.
- chrisseaton 7y agoI didn't say a hundred million per company. > Honest argument wouldn't require such forceful correction. Please try to tone it down.