Max B

@tekknolagi
585 Followers
288 Following
1.4K Posts
Let's chat about compilers
websitehttps://bernsteinbear.com
githubhttps://github.com/tekknolagi/
bskyhttps://bsky.app/profile/bernsteinbear.com
Max B6d ago

New post by Jacob about recent heap modeling optimizations in ZJIT :D

https://railsatscale.com/2026-03-18-how-zjit-removes-redundant-object-loads-and-stores/

How ZJIT removes redundant object loads and stores

ZJIT’s optimizer now removes redundant object loads and stores, improving JIT performance of CRuby’s shape system. This post explains how the optimization works.

Rails at Scale
Show threadMax BMar 18
@pervognsen @joe tbf I used difflib a lot until very recently when I joined a ruby team
Max BMar 10
Adrian SampsonMar 10
Because I have poor self control, I made a thing to avoid looking at those increasingly terrible ACM Digital Library pages. Introducing Analog Library: https://al.radbox.org
Analog Library Premium Edition™

Max BMar 10
Timo the timoMar 10

I finally wrote out the last sections of the blog post I've been working on for what feels like months now!

https://wakelift.de/2026/03/09/making-your-jitted-code-known-let-me-count-the-ways/

This is a post only tangentially about #rakulang, more about #pldev, in particular a brief look at Stack Unwinding in general, followed by descriptions of the RtlAddFunctionTable function in the WinAPI, #libunwind's pendant, the "perf map" and "JITDUMP" formats that came from linux's perf utility, and the jit reader functionality in #gdb. There's a short mention of #valgrind at the end as well for good measure.

Thanks also to @tekknolagi who has a blog with related topics (and who already covered the perf map among other things that are also in my post)

Making your JITted Code known: Let me count the ways

AOT Compilers It has been normal and expected for a long long time that any machine code they spit out would come with a bunch of metadata that is meant to be used by different pieces of the target system. There is of course symbol names for functions, which allow

my Timotimo \this
Max BMar 8
Sharon Korean Kitchen in Boston is great. Stumbled across it and thoroughly enjoyed. Vegetarian friendly, too
Show threadMax BFeb 26
@jamey interesting, haven't heard of either of those!
Show threadMax BFeb 26
@avi unfortunately not working in firefox :( blank space where video should be
Show threadMax BFeb 26

Anyway in the process of thinking about this I sketched the tiniest interpreter generator and superinstruction generator (but not finder)

https://gist.github.com/tekknolagi/8071878faa59514e3a2155bc8798638b

interp.c

GitHub Gist: instantly share code, notes, and snippets.

Gist
Show threadMax BFeb 26
maybe cc @sbrunthaler ? I will have to see what you say about superinstructions in your papers
Max BFeb 26
So my friend Chris taught me what byte pair encoding is and then I was idly thinking about it and I wonder if people can/do use this for generating bytecode interpreter superinstructions.