Poking holes into bytecode with peephole optimisations
4 months ago
- #rust
- #peephole-optimization
- #runtime-optimization
- The article discusses initial optimizations made during the redesign and semi-porting of a runtime from C to Rust, focusing on peephole optimizations.
- Peephole optimizations are local, single-pass optimizations performed on bytecode with a window size of 3 to catch missed IR optimizations.
- Two specific peephole optimizations are detailed: 'self_move' which removes redundant move operations, and 'const_binary' which simplifies constant binary operations.
- The implementation includes observability features like the 'opt_trace!' macro for debugging and insights into optimization decisions.
- Optimizations are guarded behind an '-O1' flag to prioritize startup time, with tests ensuring correctness for expected optimization cases.