[plt-scheme] this code runs slower with modules?

From: Matthew Flatt (mflatt at cs.utah.edu)
Date: Tue Dec 19 18:48:14 EST 2006

At Tue, 12 Dec 2006 14:50:09 -0800, John Clements wrote:
> 
> On Dec 12, 2006, at 12:08 PM, Eli Barzilay wrote:
> > I get faster performance with the unit version:
> >
> >   winooski:/ssh/ccs/tmp eli> mzscheme -tmv x.ss
> >   placements per second: 3454.231433506045
> >   placements per second: 3840.2457757296465
> >   placements per second: 3477.0514603616134
> >
> >   winooski:/ssh/ccs/tmp eli> mzscheme -fmv x.ss
> >   placements per second: 2336.9946249123627
> >   placements per second: 2497.5024975024976
> >   placements per second: 2169.6680407897593
> 
> Interesting.  Well, I tried this on my intel mac laptop and observed  
> the same thing you did.  I guess that the PPC (the first machine was  
> a G5) version of mzscheme is a funny animal.  Perhaps we don't do  
> good code generation (there's some JIT stuff now, right?) for PPC.

FWIW, the improvement from `module' is slightly more than above on my
PPC machine (PowerBook, 1.5 GHz), so whatever caused the difference,
it's probably not PPC code generation.

Matthew



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