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From: jeff@aiai.ed.ac.uk (Jeff Dalton)
Subject: Re: Fannkuch revisited or Benchmarking is hard
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Date: Wed, 28 Sep 1994 15:59:32 GMT
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In article <Cwqt17.KA8@aplcenmp.apl.jhu.edu> hall@aplcenmp.apl.jhu.edu (Marty Hall) writes:
>
>Instead of continual reruns of Lisp-vs-C wars, a thread on optimizing
>would be great. Ken's example is relevant for the expert hacker, but I
>think that it would also be helpful to give some simpler examples of
>code that beginning/intermediate programmer's had trouble with, and
>what benefits resulted from certain changes.

This is an excellent idea.  A while back, I tried to generate some
interest in colleting optimization advice for the comp.lang.lisp FAQ,
but it never went anywhere.  A common view seemed to be that it would
all be too implementation-specific.  I disagree, but it's worth doing
even if I'm wrong.  The collective experience of comp.lang.lisp is
substantial, and I'm sure we can do something for both beginners/
intermediates and experts (who, after all, know some implementations
less well than others).

>If I get a chance in the next couple of days, I'll post a couple of
>examples from students and from projects at work.

I will try to find some things as well.

BTW, some of the papers Henry Baker recently made available
(ftp.netcom.com:/pub/hbaker) show how to greatly speed up 
several of the Gabriel benchmarks:

"The Boyer Benchmark at Warp Speed".  ACM Lisp Pointers V,3
(Jul-Sep 1992), 13-14. [BoyerB.ps.Z]

"The Gabriel 'Triangle' Benchmark at Warp Speed".  Lisp Pointers V,3
(Jul-Sep 1992), 15-17. [TriangB.ps.Z]

"Speeding up the 'Puzzle' Benchmark a 'Bit'".  ACM Lisp Pointers V,3
(Jul-Sep 1992), 18-21. [PuzzleB.ps.Z]

"A Tachy 'TAK'".  ACM Lisp Pointers V,3 (Jul-Sep 1992), 22-23. [TakB.ps.Z]

These papers are well worth reading and also show Common Lisp in
a good light (useful representations for bit vectors, easy to memoize).

-- jeff
