Very cool. While obviously not ideal, the results are probably accurate within a small factor. Unfortunately there's no assembly version for 65C02 but Z80 does surprisingly well in this test.

I muse what could be done with modern cross-compiler (SAT solving for optional code sequences?) A llvm backend for Z80 has recently kicked back into gear: https://github.com/jacobly0/llvm-project

I ran the C version of this benchmark using llvm-mos's Clang for the 6502. The results:

21.4 seconds 5793 bytes

Which is middle of thepack for the Z80 benchmarks, but well below the 6502 ones. We're also using a slightly tweaked embedded printf written in C, so this could probably be improved somewhat there, sans any compiler changes.

Wow, I didn't realise there was a project to add a 6502 target to LLVM. Now to get Rust working...