Beating the Compiler
5 days ago
- The author wrote a fast interpreter for the Uxn CPU in assembly, achieving about 30% speedup over a Rust baseline.
- Compilers are inefficient for interpreters due to difficulties with indirect threading and keeping state in registers.
- The assembly implementation uses threaded code where each opcode jumps directly to the next, and stores all critical state in registers.
- Performance benchmarks on Fibonacci and Mandelbrot programs show the assembly version is fastest, while centralized dispatch is nearly as slow as the baseline.
- Strategies like computed goto or Massey Meta Machine are not feasible in Rust, but assembly provides precise control for optimization.
- Porting the assembly code to x86-64 is left as a future challenge.