Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
YJIT: Dive into Ruby's JIT compiler written in ...
Search
Takashi Kokubun
September 23, 2022
Programming
1
2.2k
YJIT: Dive into Ruby's JIT compiler written in Rust / Rust.Tokyo 2022
Rust.Tokyo 2022
Takashi Kokubun
September 23, 2022
Tweet
Share
More Decks by Takashi Kokubun
See All by Takashi Kokubun
Deoptimization: How YJIT Speeds Up Ruby by Slowing Down / RubyKaigi 2025
k0kubun
2
3.2k
YJIT Makes Rails 1.7x faster / RubyKaigi 2024
k0kubun
7
14k
Ruby JIT Hacking Guide / RubyKaigi 2023
k0kubun
2
10k
Towards Ruby 4 JIT / RubyKaigi 2022
k0kubun
3
11k
Optimizing Production Performance with MRI JIT / RubyConf 2021
k0kubun
1
470
Why Ruby's JIT was slow / RubyKaigi Takeout 2021
k0kubun
3
1.9k
数時間かかる週一リリースを毎日何度も爆速でできるようにするまで / CI/CD Conference 2021
k0kubun
21
14k
Ruby 3 JIT's roadmap / RubyConf China 2020
k0kubun
0
830
Ruby 3.0 JIT on Rails
k0kubun
9
9.4k
Other Decks in Programming
See All in Programming
LLMは麻雀を知らなすぎるから俺が教育してやる
po3rin
3
1.9k
AWS Summit Japan 2024と2025の比較/はじめてのKiro、今あなたは岐路に立つ
satoshi256kbyte
1
260
Android 15以上でPDFのテキスト検索を爆速開発!
tonionagauzzi
0
180
CEDEC 2025 『ゲームにおけるリアルタイム通信への QUIC導入事例の紹介』
segadevtech
2
740
PHPUnitの限界をPlaywrightで補完するテストアプローチ
yuzneri
0
370
あまり知られていない MCP 仕様たち / MCP specifications that aren’t widely known
ktr_0731
0
220
Streamlitで実現できるようになったこと、実現してくれたこと
ayumu_yamaguchi
2
270
Claude Code派?Gemini CLI派? みんなで比較LT会!_20250716
junholee
1
800
Comparing decimals in Swift Testing
417_72ki
0
160
NEWT Backend Evolution
xpromx
1
170
MySQL9でベクトルカラム登場!PHP×AWSでのAI/類似検索はこう変わる
suguruooki
1
280
AI Ramen Fight
yusukebe
0
120
Featured
See All Featured
[Rails World 2023 - Day 1 Closing Keynote] - The Magic of Rails
eileencodes
35
2.5k
Keith and Marios Guide to Fast Websites
keithpitt
411
22k
Product Roadmaps are Hard
iamctodd
PRO
54
11k
Java REST API Framework Comparison - PWX 2021
mraible
32
8.8k
How GitHub (no longer) Works
holman
314
140k
Build your cross-platform service in a week with App Engine
jlugia
231
18k
Bash Introduction
62gerente
614
210k
GitHub's CSS Performance
jonrohan
1031
460k
Intergalactic Javascript Robots from Outer Space
tanoku
272
27k
Balancing Empowerment & Direction
lara
1
530
Building Flexible Design Systems
yeseniaperezcruz
328
39k
Producing Creativity
orderedlist
PRO
346
40k
Transcript
YJIT: Dive into Ruby's JIT compiler written in Rust @k0kubun
/ Rust.Tokyo 2022
Me • @k0kubun • Shopify ◦ YJIT team • Ruby
committer ◦ MJIT maintainer
What’s YJIT?
None
None
None
None
How does YJIT work?
How YJIT works Ruby code
How YJIT works 1 + 2 Parse Ruby code Abstract
Syntax Tree
How YJIT works 1 + 2 Parse Ruby code Abstract
Syntax Tree putobject 1 putobject 2 opt_plus leave Compile Bytecode
How YJIT works 1 + 2 Parse Ruby code Abstract
Syntax Tree putobject 1 putobject 2 opt_plus leave Compile JIT Bytecode Machine code
How YJIT works putobject 1 putobject 2 opt_plus leave JIT
? Machine code Bytecode
How YJIT works: Ruby 3.1 putobject 1 putobject 2 opt_plus
leave x86_64 Codegen Machine code Bytecode
How YJIT works: Ruby 3.2 putobject 1 putobject 2 opt_plus
leave Machine code Bytecode
How YJIT works: Ruby 3.2 putobject 1 putobject 2 opt_plus
leave Machine code Bytecode
Lazy Basic Block Versioning
Lazily compile basic blocks
getlocal a getlocal b opt_plus setlocal c getlocal c putobject
1 opt_gt branchunless getlocal a leave getlocal b leave Lazily compile basic blocks
Lazily compile basic blocks
getlocal a getlocal b opt_plus setlocal c getlocal c putobject
1 opt_gt branchunless Branch stub Branch stub Lazily compile basic blocks
getlocal a getlocal b opt_plus setlocal c getlocal c putobject
1 opt_gt branchunless getlocal a leave Branch stub Lazily compile basic blocks
getlocal a getlocal b opt_plus setlocal c getlocal c putobject
1 opt_gt branchunless getlocal a leave Branch stub Lazily compile basic blocks
getlocal a getlocal b opt_plus setlocal c getlocal c putobject
1 opt_gt branchunless getlocal a leave getlocal b leave Lazily compile basic blocks
Why lazy compilation? 1. Better code locality a. Only compile
used paths b. Related code is put together
Why lazy compilation? 1. Better code locality a. Only compile
used paths b. Related code is put together 2. More type information
Type Profiling
Type Profiling getlocal a getlocal b opt_plus
Type Profiling getlocal a getlocal b opt_plus
Type Profiling getlocal a getlocal b jmp regenerate
Type Profiling getlocal a getlocal b jmp regenerate
Type Profiling getlocal a getlocal b jmp regenerate a: 1
b: 2
Type Profiling getlocal a getlocal b opt_plus (int) setlocal c
getlocal c putobject 1 opt_gt branchunless
Passes • CodeGen -> Split -> Alloc Regs
Passes • CodeGen -> Split -> Alloc Regs
IR
IR Split
IR Split Alloc Regs
Rust Challenges
Clang and Bindgen Clang dependency or Per-architecture codegen?
Mutable Borrow
Next steps • Code GC • Register allocation • Method
inlining
Conclusion • We reviewed the architecture of YJIT • Rust
has been useful for transforming IR