3 ms·

I think optimizations passes is what takes the most time in a compiler. Older compilers did a lot less.

• andi999 6y ago
  Well then at leastbwith -O0 should be similiar times achievable?
  • TazeTSchnitzel 6y ago
    Modern compilers are still pass-based with an optimisation-friendly IR even if you skip the actual optimisation passes. A single-pass compiler will be faster because it does not have the overhead of doing things in multiple passes.
  • Touche 6y ago
    Turbo pascal was single pass, parse and compile.
  • pkaye 6y ago
    -O0 still does some optimization from what I can find online. Maybe someone knows more specifics since the manual is pretty brief.
    • guenthert 6y ago
      I can only confirm that -O0 performs some optimization, which can be annoying when single-stepping through the code (cough, cough) using a debugger. Hence gcc offers -Og to suppress those optimizations (not sure, whether that in itself causes some debugging info to be added though).