Blog

• A fuzzer for the Toy Optimizer
  February 25, 2026
• Type-based alias analysis in the Toy Optimizer
  February 16, 2026
• A multi-entry CFG design conundrum
  January 22, 2026
• The GDB JIT interface
  December 30, 2025
• Load and store forwarding in the Toy Optimizer
  December 24, 2025
• ZJIT is now available in Ruby 4.0
  December 24, 2025
• How to annotate JITed code for perf/samply
  December 18, 2025
• A catalog of side effects
  November 11, 2025
• Walking around the compiler
  September 23, 2025
• Linear scan with lifetime holes
  August 24, 2025
• Liveness analysis with Datalog
  August 13, 2025
• Linear scan register allocation on SSA
  August 13, 2025
• How to use snprintf
  August 9, 2025
• ClassDistribution from S6 JIT is really neat
  July 2, 2025
• Heating water from afar
  June 24, 2025
• Travel notes: PLDI Seoul
  June 23, 2025
• What I talk about when I talk about IRs
  June 12, 2025
• Zero-overhead checks with fake stack overflows
  May 28, 2025
• A simple search engine from scratch*
  May 20, 2025
• ZJIT has been merged into Ruby
  May 14, 2025
• Writing that changed how I think about PL
  May 13, 2025
• Precedence climbing
  May 4, 2025
• Nix derivations by hand, without guessing
  April 5, 2025
• Parsing to IR and lvalues
  March 27, 2025
• Prospero challenge, now with more garbage collection
  March 24, 2025
• Optimizing Django by not being silly
  March 23, 2025
• Visualizing big data
  March 21, 2025
• Representing type lattices compactly
  March 10, 2025
• Interprocedural sparse conditional type propagation
  February 24, 2025
• A catalog of ways to generate SSA
  February 11, 2025
• A compiler IR for Scrapscript
  February 4, 2025
• Weak references and garbage collectors
  January 4, 2025
• Into CPS, never to return
  December 25, 2024
• A multi-emulator Gameboy tracer
  November 21, 2024
• You can use C-Reduce for any language
  November 15, 2024
• On the universal relation
  October 27, 2024
• Adding row polymorphism to Damas-Hindley-Milner
  October 22, 2024
• Damas-Hindley-Milner inference two ways
  October 15, 2024
• What's in an e-graph?
  September 11, 2024
• microui+fenster=small gui
  September 7, 2024
• Precedence-aware pretty printing
  August 25, 2024
• Abstract interpretation in the Toy Optimizer
  July 23, 2024
• Some tricks from the Scrapscript compiler
  July 10, 2024
• TCC does support __attribute__(section(...)), actually
  June 19, 2024
• A baseline scrapscript compiler
  June 1, 2024
• Compilers for free with weval
  May 19, 2024
• Waking my computer from afar
  March 15, 2024
• Neat parallel output in Python
  February 22, 2024
• Vectorizing ML models for fun
  February 18, 2024
• scrapscript.py
  January 23, 2024
• Type information for faster Python C extensions
  January 13, 2024
• Building a small REPL in Python
  November 27, 2023
• A quick look at destination-driven code generation
  November 9, 2023
• Ninja is enough build system
  November 4, 2023
• Compiling ML models to C for fun
  September 19, 2023
• Compiling typed Python
  June 19, 2023
• Writing a symbolizer for the Cinder JIT
  November 3, 2022
• How we use binary search to find compiler bugs
  October 18, 2022
• How the Cinder JIT's inliner works
  May 2, 2022
• Recursive Python objects
  May 2, 2019
• Understanding the 100 prisoners problem
  March 11, 2019
• Bytecode compilers and interpreters
  January 4, 2019
• JumboSmash: a technical retrospective
  July 13, 2018
• How to mess with your roommate
  May 29, 2018
• Driving student programs
  April 13, 2018
• I'm confused
  January 13, 2018
• How to shoot yourself in the foot without really trying
  October 6, 2017
• An error in ML that caused me much grief
  October 19, 2016
• The cost of applying to college: data
  January 2, 2014
• A quest for anonymity
  September 20, 2012
• DNS tunneling, or, how to get around Gogo
  August 20, 2012
• Dictionary
  August 13, 2012
• New public key!
  July 25, 2012

Runtime optimization, the series

• Inline caching
  January 14, 2021
• Inline caching: quickening
  February 3, 2021
• Small objects and pointer tagging
  February 11, 2021
• Discovering basic blocks
  March 26, 2022
• Inline caches in the Skybison Python runtime
  November 7, 2022

Compiling a Lisp, the series

• Compiling a Lisp: Overture
  August 29, 2020
• Compiling a Lisp: The smallest program
  August 30, 2020
• Compiling a Lisp: Integers
  August 31, 2020
• Compiling a Lisp: Booleans, characters, nil
  September 2, 2020
• Compiling a Lisp: Primitive unary functions
  September 5, 2020
• Compiling a Lisp: Primitive binary functions
  September 16, 2020
• Compiling a Lisp: Reader
  September 22, 2020
• Compiling a Lisp: Let
  October 1, 2020
• Compiling a Lisp: If
  October 7, 2020
• Compiling a Lisp: Heap allocation
  October 11, 2020
• Compiling a Lisp: Instruction encoding interlude
  October 19, 2020
• Compiling a Lisp: Labelled procedure calls
  October 29, 2020
• Compiling a Lisp: Closure conversion
  August 10, 2025

Writing a Lisp, the series

• Writing a Lisp, Part 0: Fundamentals
  October 27, 2016
• Writing a Lisp, Part 1: Booleans
  October 28, 2016
• Writing a Lisp, Part 2: Symbols
  November 1, 2016
• Writing a Lisp, Part 3: Lists
  December 6, 2016
• Writing a Lisp, Part 4: Environments
  December 19, 2016
• Writing a Lisp, Part 5: If-Expressions
  December 19, 2016
• Writing a Lisp, Part 6: Primitives 1
  December 27, 2016
• Writing a Lisp, Part 7: Primitives 2
  January 18, 2017
• Writing a Lisp, Part 8: ASTs
  January 31, 2017
• Writing a Lisp, Part 9: Quote
  February 1, 2017
• Writing a Lisp, Part 10: Closures
  February 7, 2017
• Writing a Lisp, Part 11: Primitives 3
  February 9, 2017
• Writing a Lisp, Part 12: Metacircular Evaluator
  March 1, 2017
• Writing a Lisp, Part 13: Let
  March 14, 2017
• Writing a Lisp, Part 14: Comments
  March 15, 2017
• Writing a Lisp, Part 15: I/O
  March 18, 2017
• Writing a Lisp, Part 16: Standard Library
  March 22, 2017
• Writing a Lisp, Part 17: Modules
  May 2, 2017
• Writing a Lisp, Part 18: No Define
  May 11, 2017