Monday, January 28, 2008

RPython GCLB Benchmark - Recursive

Must admit that I am a big fan of python (the programming language), and when I saw the benchmark that RPython can be faster than C (on the binary tree benchmark from the Great Computer Language Shootout - GCLS), I just had to try RPython on another problem from GCLS, so I chose the one with worst performance compared to C/gcc (266 times slower) - recursive (with various recursive methods, e.g. Ackerman, Fibonacci and Tak). Results were roughly that rpython was 50-100 and gcc/c was 100-300 times faster than python (note: I only did one run, so numbers can be somewhat bogus, but not too bad I think).

Unfortunately for the run with n=11 Ackerman had consumed all the stack, but that can be solved with Stackless RPython.


cfbolz said...

Interesting. It seems unlikely that RPython's garbage collector is to blame for the error for n=11, because all the actual computations don't really use any dynamically allocated memory (only the printing does). Which version of PyPy did you use? 1.0? Or the latest SVN?

Amund Tveit said...

I used the one from svn. Which version should I try with?

cfbolz said...

The one from SVN is perfect. I am amazed that RPython does so badly, the generated C should be very close to the manually written C code.

Isaac Gouy said...

"Great Computer Language Shootout - GCLS"

It's called - The Computer Language
Benchmarks Game
(benchmarks game).

Amund Tveit said...

Isaac, you are right, thanks :)