@cfbolz

PyPy/RPython contributor. Half time teaching at Uni Düsseldorf. Works on dynamic language implementations. Vegan. they/them Mainly on @cfbolz@mastodon.social

 Duisburg, Germany
cfbolz.de
Joined April 2008
  • Tweets14.1K
  • Following1K
  • Followers2.5K
761Media
I found the most German of five-star reviews 😅("CAN'T COMPLAIN!" – probably really a genuine compliment.)
Screenshot of five-star review with German text "KANN NICHT KLAGEN!"

ALT Screenshot of five-star review with German text "KANN NICHT KLAGEN!"

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This is a wonderful writeup of a bunch of folk knowledge that we don't want to lose! (About tracing JITs.)
The PyPy Project@pypyproject6 Jan 2025
"Musings on Tracing in PyPy" pypy.org/posts/2025/01/musin… blog post version of a Twitter discussion with @ShriramKMurthi, @cfbolz and some others, last summer.

Musings on Tracing in PyPy

Last summer, Shriram Krishnamurthi asked on Twitter: "I'm curious what the current state of tracing JITs is. They used to be all the rage for a while, then I though I heard they weren't so effective,

pypy.org
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CF Bolz-Tereick retweeted
The PyPy Project@pypyproject23 Oct 2024
"A DSL for Peephole Transformation Rules of Integer Operations in the PyPy JIT" pypy.org/posts/2024/10/jit-p… new post on the PyPy blog by @cfbolz

A DSL for Peephole Transformation Rules of Integer Operations in the P

As is probably apparent from the sequence of blog posts about the topic in the last year, I have been thinking about and working on integer optimizations in the JIT compiler a lot. This work was mainl

pypy.org
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Sophie Kaleba@SophieKaleba10 Sep 2024
Hi! I am looking for job opportunities around programming languages and their tooling, as I just submitted my PhD thesis on optimizing dynamic languages. Please get in touch if you know of a position or if you are hiring! More about me @ sophie-kaleba.github.io
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The PyPy Project@pypyproject28 Aug 2024
PyPy 7.3.17 released, with support for Python versions 2.7 and 3.10 🎉 Highlights are an improved repl (thanks CPy devs!), knownbits-optimization in the JIT, and a RISC-V JIT backend (without binary releases though): pypy.org/posts/2024/08/pypy-…

PyPy v7.3.17 release

PyPy v7.3.17: release of python 2.7 and 3.10 The PyPy team is proud to release version 7.3.17 of PyPy. This release includes a new RISC-V JIT backend, an improved REPL based on work by the CPython tea

pypy.org
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I haven't done any streaming in ages. Will do a bit of work on Pydrofoil in ~80 minutes, at 13:30 UTC, on twitch.tv/pypyproject The goal will be to look into Cheri-RISC-V, specifically CHERIoT: cheriot.org/

pypyproject - Twitch

Occasional PyPy development stream — pypyproject streams live on Twitch! Check out their videos, sign up to chat, and join their community.

twitch.tv
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The PyPy Project@pypyproject16 Aug 2024
Making the PyPy GC and JIT make sounds: youtube.com/watch?v=drwJBzDM… (by @cfbolz)

Making PyPy's GC and JIT produce a sound

the video shows the effect of a hacky script that will play a sound...

youtube.com
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The PyPy Project@pypyproject3 Aug 2024
New blog post by @cfbolz: "A Knownbits Abstract Domain for the Toy Optimizer, Correctly" pypy.org/posts/2024/08/toy-k…

A Knownbits Abstract Domain for the Toy Optimizer, Correctly

After Max' introduction to abstract interpretation for the toy optimizer in the last post, I want to present a more complicated abstract domain in this post. This abstract domain reasons about the ind

pypy.org
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Guilherme Espada@GuiEspada23 Jul 2024
SIGPLAN-AV and the PLDI24 Video Volunteers present: The PLDI24 videography. youtube.com/@acmsigplan/vide… Over 200 videos are now available. If we made an error, please contact us at the email listed in sigplan.org/AV/ Big thanks to the Video Volunteers whose (cont)

ACM SIGPLAN

Special Interest Group on Programming Languages The ACM Special Interest Group on Programming Languages (SIGPLAN) explores programming language concepts and tools, focusing on design, implementation,...

youtube.com
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The PyPy Project@pypyproject19 Jul 2024
"Mining JIT traces for missing optimizations with Z3", blog post by @cfbolz, in which they identify a large number of missing integer optimizations in PyPy's JIT using an SMT solver pypy.org/posts/2024/07/minin…

Mining JIT traces for missing optimizations with Z3

In my last post I've described how to use Z3 to find simple local peephole optimization patterns for the integer operations in PyPy's JIT. An example is int_and(x, 0) -> 0. In this post I want to scal

pypy.org
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To provide some more details for Felix's paper. A long problem frustrating interpreter and JIT compiler optimization is optimizing across native code modules. CPython, e.g., cannot "see" into NumPy. Felix showed how C extensions can register optimizations in CPython. The...
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CF Bolz-Tereick retweeted
The PyPy Project@pypyproject12 Jul 2024
Now blog post by @cfbolz: 'Finding Simple Rewrite Rules for the JIT with Z3' How to use the Z3 API to find simple rewrites of integer operations, such as x & 0 -> 0 pypy.org/posts/2024/07/findi…

Finding Simple Rewrite Rules for the JIT with Z3

In June I was at the PLDI conference in Copenhagen to present a paper I co-authored with Max Bernstein. I also finally met John Regehr, who I'd been talking on social media for ages but had never met.

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Slava Egorov@mraleph26 Jun 2024
Today I am stepping into a new role on the @dart_lang team: I will be taking care of overall technical direction of the project as an uber-TL. Very excited to work across the whole Dart platform and together with my Flutter peers tackle all the challenges ahead of us.
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The PyPy Project@pypyproject23 Jun 2024
Performance isn't the property of a language but of implementations. PyPy runs a naive Collatz for the numbers 1 to 1,000,000,000 in about 4 min. By adding a cache for the number of steps for all the numbers, the time goes down to 30s. Code (by @cfbolz): gist.github.com/cfbolz/4bfa8…

collatz in Python, naive version plus one with a bit of caching

collatz in Python, naive version plus one with a bit of caching - collatzcache.py

gist.github.com
Walker Boh
@nakedMCSE19 Jun 2024
Replying to @VictoriqueM
Had to try the Python version just to see. Its 100x times slower, and this is just for 1M entries and not the 1B the others were doing... Python was never suited to this, but I had to see.
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Djamila Aouada@AouadaDjamila20 Jun 2024
1/3 I’m currently @CVPR in Seattle, having traveled from Europe with my daughters, including a 5-month-old I am nursing. I was particularly excited to share this experience with my eldest daughter. However, I was taken aback when kids were not allowed in. #cvpr2024
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Geoff Langdale
@geofflangdale6 Jun 2024
Since my Twitter seems to be comprised of many people with longer attention spans, greater formal training in logic/math, or just plain smarter than I am, I'm going to ask this one: How do we characterize which logical functions on a bunch of bits can be emulated with an ...
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The PyPy Project@pypyproject4 Jun 2024
We just merged the "known bits" JIT optimization. It allows the JIT to reason about specific bits of integer variables that are known to be 0 or 1. This makes bit-manipulation code faster, sometimes significantly so. Work was done by Niko Rittinghaus and @cfbolz
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The PyPy Project@pypyproject31 May 2024
Great blog post by Chris Siebenmann: "PyPy has been quietly working for me for several years now" utcc.utoronto.ca/~cks/space/…
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The PyPy Project@pypyproject15 May 2024
New blog post: "Profiling PyPy using the Firefox profiler user interface". pypy.org/posts/2024/05/vmpro… Christoph Jung describes how to convert vmprof profiles from PyPy (CPython works too) to a format the Firefox profiler can then visualize.

Profiling PyPy using the Firefox profiler user interface

Introduction If you ever wanted to profile your Python code on PyPy, you probably came across VMProf — a statistical profiler for PyPy. VMProf's console output can already give some insights into wher

pypy.org
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Michael Hudson-Doyle@mwhudson5 May 2024
Replying to @cfbolz
Yeah I was looking at the PR and this looks like it will increase the "Michael's snarky comment" level of the cpython repo by quite a bit
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