From: Charles Oliver Nutter <charles.nutter@...>
Date: 2009-04-11T05:28:42+09:00
Subject: Re: Python on LLVM

Tony Arcieri wrote:
> Actually I believe they're doing both: trying to build the interpreter
> itself with LLVM, and then adding an LLVM-based JIT, or at least that's what
> I gathered from their roadmap.
> 
> They're basically trying everything they can to make CPython faster.

It's probably also worth pointing out that the majority of Ruby 
application performance problems are due to the core classes, object 
churn, and GC overhead, none of which are easy to improve with a better 
compiler or execution engine. JRuby's had much better execution 
performance than CRuby for well over a year, but only recently are we 
comfortably faster at running applications like Rails. That's largely 
because it takes a lot longer to optimize all the core classes, 
certainly longer than optimizing execution.

It's also unclear whether Psyco or Unladen Swallow actually help 
application performance; in both cases they usually post perf numbers on 
execution-bound microbenchmarks. When the bulk of your application's 
time is spent manipulating Strings or Arrays, faster code execution can 
only help so much.

- Charlie