Despite 30 months work, core developer says Python's JIT compiler is often slower than the interpreter
Despite 30 months work, core developer says Python's JIT compiler is often slower than the interpreter • DEVCLASS
python is a language explicitly designed to resist any form of proper optimization. It just can't be made fast
it doubled in speed from 3.9 to now, so it's getting there.
This is a common misconception! It is true that, of the Smalltalk descendants, Python was not designed for speed like Self or Java; but it was not designed to be slow or difficult to compile. The main technique required to implement a Python JIT is virtualizable objects, which allows the JIT to temporarily desynchronize the contents of registers from the contents of the heap; it's not obvious and wasn't in the first few iterations of PyPy. Additionally, it turns out that tracing the meta-level (see docs or the paper) is a key trick: instead of JIT'ing the Python program, the JIT operates on the interpreter, on the Python VM itself!
Python typing system is the reason of its huge flexibility, but as many other scripting language, it’s also what makes it so hard to optimize.
I have no idea how you can change that without bringing some “JIT-oriented” features inside the Python language itself.
I still hope for the best, but I’m unsure we will be able to see an efficient JIT system inside CPython soon.
PyPy had to rewrite the whole Python implementation in a JIT focused way, and even with that, they are (not uncommon) cases when PyPy is slower.
I gather that you don't actually use PyPy much. On average, I expect PyPy to deliver over a 3x speedup. The main issue is that people have built upon slow libraries like Numpy that only seem fast because CPython is even slower.
The reason that CPython cannot have a JIT added on is architectural and political. The CPython core team refuses to learn lessons from PyPy.
I'm a fan of type infrence languages
i'm a fan of ladies with complete test coverage
but i'm ok with those who are a fan of type inference.
More ladies for me
Microsoft cancelled its support for the Faster CPython project in May this year, as part of a round of layoffs
wtf did they actually axe Guido? I thought he was heavily involved in that.
His website still says he works for Microsoft, though it's possible he hasn't updated it yet.
Please don't show a close-up image of a snake, or at least add a spoiler! It's irrelevant to the topic, and it just sets some of us on edge for no good reason. If it's small, it's fine, but this... holy shit, now I have a headache. It's one of the reasons I stopped coding in Python altogether.
Snake, a snake
Oh, it's a snake
Severus Snake. Dumbledore!
Ah sorry, wrong sketch.
But looms at his little puppy dog face. :3
lol I get it, but it's involuntary. I really wish I could like snakes but I don't think it's happening anytime soon.
This is not entirely fair because the comparison point has changed. CPython is getting much faster, too, thanks to the optimizations stages before the JIT runs.