3 ms·

JIT compilation can be faster for compiled languages too, as it allows data driven inlining and devirtualization, as well as "effective constant" propogation an

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

varjag 1y ago
It can be but it never is.
- __s 1y ago
  Especially after PGO (profiling guided optimization) gets most of the way there
- ignoramous 1y ago
  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]. [0] https://lwn.net/Articles/995397/ https://lwn.net/Articles/995397/ [1] https://news.ycombinator.com/item?id=40868224 https://news.ycombinator.com/item?id=40868224 [2] https://news.ycombinator.com/item?id=42896716 https://news.ycombinator.com/item?id=42896716
- Rohansi 1y ago
  But is that because of JIT compilation or other decisions for how the language should work (dynamic typing, GC, etc.)?
- ranger_danger 1y ago
  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.
duped 1y ago
Is there a production JIT for a compiled language that is actually faster? I understand the theory, I don't think the practice backs it up.
- fragmede 1y ago
  Depends, what do you consider Java?
  - varjag 1y ago
    Java is certainly not the fastest language out there.
    - pcwalton 1y ago
      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.
- pcwalton 1y ago
  I believe HotSpot is usually faster than GCJ.

varjag 1y ago

It can be but it never is.

__s 1y ago
Especially after PGO (profiling guided optimization) gets most of the way there
ignoramous 1y ago
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]. [0] https://lwn.net/Articles/995397/ https://lwn.net/Articles/995397/ [1] https://news.ycombinator.com/item?id=40868224 https://news.ycombinator.com/item?id=40868224 [2] https://news.ycombinator.com/item?id=42896716 https://news.ycombinator.com/item?id=42896716
Rohansi 1y ago
But is that because of JIT compilation or other decisions for how the language should work (dynamic typing, GC, etc.)?
ranger_danger 1y ago
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.

duped 1y ago

Is there a production JIT for a compiled language that is actually faster? I understand the theory, I don't think the practice backs it up.

fragmede 1y ago
Depends, what do you consider Java?
- varjag 1y ago
  Java is certainly not the fastest language out there.
  - pcwalton 1y ago
    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.
pcwalton 1y ago
I believe HotSpot is usually faster than GCJ.