About

Hi! My name is Kohei Asano, I use khei4 on the Internet.

I’m a Software Engineer at Sony Interactive Entertainment, working on PS5 WebKit.

I studied Mathematics at the University of Hokkaido and Computer Science at the University of Tokyo.

Feel free to contact me via GitHub, LinkedIn, X.

Experiences

Projects

• Selected Fellow, IPA Mitou 2023 – “RiP: High-Efficiency Reservoir-in-Processor Computing Utilizing Internal State of RISC-V Processors” (Ja)
  • Designed a reservoir-computing architecture that re-uses RISC-V micro-architectural state as the nonlinear reservoir.
  • I created RISC-V emulator, that has branch predictions and stats calculator for that.

Open sources contributions

• LLVM – Middle-end passes like, MemCpyOpt, InstCombine.
  • Google Summer of Code Final Report
    • Japanese Blog about that

• WebKit – Windows Rendering, and Refactorings.

• Polynomial Invariant calculator – Rust implementation of C-subset Parser and Algebraic Invariant Computation using Groebner basis for my Undergraduate Poster session.

• Symbolic Differentiator – Rust implementation of Mathematical Expression Parser and Differentiation algorithm on the paper.
  • Japanese blog

Presentations

• Presentation about Stack-Move Optimization I implemented on GSoC at Kernel/VM探検隊 No16 (English slides, Japanese video)

• Presentation about Undergraduate Poster: Inference of polynomial invariants for imperative programs (English slides)

• Introduction of Clippy await warning about Lock/RefCellRef (Japanese slides, Japanese Blog)

• Survey about Syntax-Guided Synthesis (English slides)

• Eulerian cycle, Rust, Bit tricks at Hokkaido University HUIT-Club Seminar.(Japanese slides)

Theses and Posters

• Rust Implementation of Polynomial Invariant Computation using Groebner Basis[Undergraduate Mathematics]
  (pdf) (slides)
• Master Thesis: Finding Missing Automatic Vectorization Opportunity by Differential Testing [Graduate CS]
  (pdf)
• Could LLM be LLVM superoptimizer? [xSig 2023]
  (Japanese poster)
  • I implemented LLVM middle-end path, that asks ChatGPT to optimize the peephole optimization tests, and evaluate them by llvm-mca.
  • Got Poster Award.

Miscellaneous

• TechBookFest Japanese Leaflet writing
  Explaining about LLVM overview and steps tweaking LLVM Frontend to parse Python-subset language.

• LifeGame by pure JS
  A JS-practice implementation of Conway’s Game of Life, configurable in detail.