CF Bolz-Tereick

@cfbolz
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PyPy/RPython contributor. Half time teaching at Uni Düsseldorf. Works on dynamic language implementations. Vegan. Love street art and art in public spaces, hiking, reading.
they/them
websitehttps://www.cfbolz.de
CF Bolz-Tereick1d ago
Andy Wingo1d ago
the nice thing about javascript is that there are so many kinds of scope. truly an embarrassent of riches
CF Bolz-Tereick1d ago
Max B1d ago

Also forgot to mention some small fun with Z3

https://bernsteinbear.com/blog/asm-z3/

Checking assembly with Z3

Short post today. New ZJIT contributor dak2 submitted a PR to fix an overflow bug in fixnum division in ZJIT. We did the division fine, but lied about the type of the result in the case of dividing FIXNUM_MIN by -1. You can see how this is special-cased in CRuby:

Max Bernstein
CF Bolz-Tereick4d ago
Show threadCF Bolz-Tereick4d ago
@regehr @pkhuong here's the variants that I know are used in at least one project. It's all equivalent of course, but mentally switching between them is always annoying
CF Bolz-Tereick5d ago
Just blogged: "KnownBits in Lean" https://cfbolz.de/posts/2026-knownbits-in-lean/
KnownBits in Lean

In January I was at the excellent E-Graphs Dagstuhl where I met some really amazing people. One of the things I did during that week was to talk to Marcus Rossel and Andrés Goens about proving the sou

CF Bolz-Tereick's Web Page
CF Bolz-TereickMay 29
Chung-chieh Shan 單中杰May 29
Academic peer review is a print-read-eval loop
CF Bolz-TereickMay 20
mattpdMay 20
Verifying EDA and compiler optimizations once and for all
https://samuelcoward.co.uk/blog/2026/parabit/
A Multi-Width Parametric Bitvector Equivalence Solver
https://samuelcoward.co.uk/assets/pdf/Parabit.pdf
CAV 2026
Luigi Rinaldi, John Wickerson, Samuel Coward
CF Bolz-TereickMay 1
aramyaMay 1
there is a backdoor in the futex syscall that secretly calls the 202th futamura projection
Show threadCF Bolz-TereickMay 1
I found a super similar one! Another nonbinary giant using a house as a backpack after the apocalypse!
CF Bolz-TereickApr 30
John RegehrApr 29
exhibits A and B
CF Bolz-TereickApr 30
Thalia ArchibaldApr 29

Look what I found today! It's Martin Newell's 1975 dissertation on procedural modeling, with the first appearance of the Utah teapot! 🧵

Scan: https://collections.lib.utah.edu/ark:/87278/s651906h

#retrocomputing #vintagecomputing #graphics #utah