[Python-Dev] Python 3 optimizations continued...

[stefan brunthaler]

> Does it speed up Python? :-) Could you provide numbers (benchmarks)?
>
Yes, it does ;)

The maximum overall speedup I achieved was by a factor of 2.42 on my
i7-920 for the spectralnorm benchmark of the computer language
benchmark game.

Others from the same set are:
  binarytrees: 1.9257 (1.9891)
  fannkuch: 1.6509 (1.7264)
  fasta: 1.5446 (1.7161)
  mandelbrot: 2.0040 (2.1847)
  nbody: 1.6165 (1.7602)
  spectralnorm: 2.2538 (2.4176)
  ---
  overall: 1.8213 (1.9382)

(The first number is the combination of all optimizations, the one in
parentheses is with my last optimization [Interpreter Instruction
Scheduling] enabled, too.)

For a comparative real world benchmark I tested Martin von Loewis'
django port (there are not that many meaningful Python 3 real world
benchmarks) and got a speedup of 1.3 (without IIS). This is reasonably
well, US got a speedup of 1.35 on this benchmark. I just checked that
pypy-c-latest on 64 bit reports 1.5 (the pypy-c-jit-latest figures
seem to be not working currently or *really* fast...), but I cannot
tell directly how that relates to speedups (it just says "less is
better" and I did not quickly find an explanation).
Since I did this benchmark last year, I have spent more time
investigating this benchmark and found that I could do better, but I
would have to guess as to how much (An interesting aside though: on
this benchmark, the executable never grew on more than 5 megs of
memory usage, exactly like the vanilla Python 3 interpreter.)

hth,
--stefan