[racket-dev] Fwd: [shootout-Feature Requests][312552] Scheme PLT should be renamed to Racket

From: Vincent St-Amour (stamourv at ccs.neu.edu)
Date: Fri Jun 18 11:41:57 EDT 2010

At Fri, 18 Jun 2010 10:05:57 -0500,
Robby Findler wrote:
> Perhaps it suggests a bug in the interaction between that fancy
> require operator and the optimizer?

Actually, the benchmark on the shootout webpage is named
mandelbrot-unsafe.rkt in the repository. The version I had in mind is
mandelbrot.rkt, which does use fl+ without renaming it.

After running mandelbrot-unsafe.rkt 50 times, it does show some
variance in the running times (it runs for between 7 and 10 seconds,
with times following what looks like a normal distribution), but much
less than mandelbrot.rkt (between 19 and 40 seconds, with times
following a bimodal distribution, with peaks around 20 and 40). The
small variation for mandelbrot-unsafe.rkt (combined with the fact that
times are distributed normally) indicates that it's probably noise. On
the other hand, the bimodal distribution observed on mandelbrot.rkt is
probably a sign that something weird is going on.

The slowdown observed on the shootout webpage, since it's based on
mandelbrot-unsafe.rkt, could thus be caused by the upgrade to 5.0. The
running time inconsistencies due to fl+ and co is likely a separate


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