[Python-Dev] Optimization targets

Jeremy Hylton jeremy at alum.mit.edu
Thu Apr 15 23:25:56 EDT 2004


On Thu, 2004-04-15 at 15:07, "Martin v. Löwis" wrote:
> Jeremy Hylton wrote:
> > Another question that I'd love to hear the answer to: What's the
> > difference between Pysco and something like this Self implementation or
> > the HotSpot Java implementation?  
> 
> Psyco is specializing, and that is the main difference compared
> to Java Hotspot. If you have a program

That's a helpful clarification, thanks.

> In Hotspot, the type of f would already be defined in the Java
> source code, and Hotspot generates native machine instructions
> for it.
> 
> The changes over standard JIT appear to be inlining; it also
> appears to do inlining of virtual functions, combined with
> a type check to detect cases where the a different functions
> should have been called compared to the last time the virtual
> call was made.

I'm not sure what you mean by the changes over standard JIT.  Do you
mean the difference between Hotspot and "standard JIT"?  Your
descriptions sounds a bit like the Deutsch and Schiffman inline method
cache, which doesn't inline the method body but does inline the method
lookup.  Or does Hotspot actually inline methods?

Jeremy





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