cfbolztereick

4 ms·

1.
by cfbolztereick 7mo ago
Exactly correct. PyPy is a replacement for CPython 3.11, which aims to be fully compatible with pure Python code (C extensions are a more complicated story).
2.
by cfbolztereick 7mo ago
Timely management of external resources is what the `with` statement has been for since 2006, added in python 2.5 or so. To debug these problems Python has Resource Warnings. Additionally, CPython's gc is also only eager in a best effo
3.
by cfbolztereick 7mo ago
PyPy isn't unmaintained. We are certainly fixing bugs and are occasionally improving the jit. However, the remaining core devs (me among them) don't have the capacity to keep up with cpython. So for supporting new cpython versions
4.
by cfbolztereick 1y ago
The English term for 'Bildungsroman' is actually... 'bildungsroman' https://en.wikipedia.org/wiki/Bildungsroman
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by cfbolztereick 2y ago
Complaining about a rest (however long) in a piece by the composer of 4'33'' is certainly A Take.
6.
by cfbolztereick 2y ago
This is really fun, I'm getting badly nerd sniped by this.
7.
by cfbolztereick 2y ago
It should get pretty good performance yes. Not sure how native like we get with the jit. Gut feeling would be a bit slower than gcc -O0? I would be very interested in your experience if you do try it.
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by cfbolztereick 2y ago
The equivalent of this (and strongly inspired by luajit's ffi) in the python world is cffi, btw: https://cffi.readthedocs.io/en/stable/
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by cfbolztereick 2y ago
And a significant chunk of these important extension libraries are supported in pypy using the emulated C-extension api (cpyext)
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by cfbolztereick 2y ago
Yeah, that's exactly right. It's operating on an SSA-based intermediate representation. So if an operation gets removed, the arguments are still being computed. The earlier operations that produce those arguments can also be remov
11.
by cfbolztereick 2y ago
I only support integer operations in the DSL so far. (but yes, turning the python expression x*y+z into an fma call would not be a legal optimization for the jit anyway. And Z3 would rightfully complain. The results must be bitwise identica
12.
by cfbolztereick 2y ago
Yeah, that's a good point! The 'empty' parts of the beginning of the program are actually a 'configure' phase, where the program runs a bunch of subprocesses (C compiler with small query programs) and the vm is most
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by cfbolztereick 2y ago
Good idea! There are various other extensions possible. Unfortunately there's a bit of an observer effect, the sounds are made with python code running in the same process, and the more complicated I made the sound generation logic, th
14.
by cfbolztereick 2y ago
Oh wow, that's just amazing, thanks for the link! From the article: ''' Interestingly, there was a technical bump or glitch in the Unity Engine. A feature that no user would normally have any control over, that caused a
15.
by cfbolztereick 2y ago
Yep, typo, thanks for pointing it out! I'm fixing it.
16.
by cfbolztereick 2y ago
PyPy has formally verified the integer abstract domain using Z3, a quite important part of our jit optimizer (will write about that in the coming weeks). We also run a fuzzer regularly to find optimization bugs, using Z3 as a correctness ch
17.
by cfbolztereick 2y ago
All the minimized inefficiencies that are found by my script are already optimizations. They just happen to be rather specific patterns, so they need to be suitably generalized. There's another Regehr etal paper about how to do that au
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by cfbolztereick 3y ago
PyPy was started early in 2003 too, the first release took a while. PyPI was branded as 'The Cheeseshop' in the early years.
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by cfbolztereick 4y ago
Yeah, that's my current project, already found a bunch of missing small features in the optimizers.
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by cfbolztereick 4y ago
There would be an actual miscalculation, yes. which is a really annoying kind of bug, also because these jit bugs tend to go away if you turn the debugger on, making them even more frustrating to track down. The ones we found so far are all
21.
by cfbolztereick 4y ago
Yeah, the generated traces are 'sensible' by construction (they don't compute anything sensible, but they are well-formed).