JIT Compiling Code in 5μs
- ID
- 17129
- Status
- summarized
- Published
- 23 Aug 2026, 2:04 PM
- Fetched
- 24 Aug 2026, 3:28 AM
- Provider
- Hacker News
- Category
- dev-community
- Original URL
- https://malisper.me/jit-compiling-code-in-5-us/
- Source URL
- https://hnrss.org/best
Summary
- Score
- 7.0
- Created
- 24 Aug 2026, 3:28 AM
- Tags
- Audience
- developersdatabase-learners
What happened
The author of pgrust details how they built a JIT compiler that compiles code in ~5μs, fast enough to JIT compile every SQL query rather than a subset. They attribute the feasibility of directly targeting assembly—historically a 'black art'—to AI assistance, and walk through building a toy regex JIT engine in Rust as a demonstration.
Why it matters
If you're building database internals or any runtime that could benefit from JIT (2-5x perf gains), AI-assisted assembly generation lowers the barrier enough that rolling your own JIT is now realistic instead of defaulting to LLVM or C codegen, both of which have high compile times. This is directly relevant to anyone evaluating Rust-based database or parser projects.
Discussion angle
Does AI-assisted assembly generation change the build-vs-buy calculus for JIT in databases—should new database projects stop reaching for LLVM and write their own 5μs JIT instead?