[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 09:26:38 EDT 2010

At Fri, 18 Jun 2010 08:18:14 -0400,
Sam Tobin-Hochstadt wrote:
> I submitted a request to the computer language shootout to rename PLT
> to Racket.  The following message shows the difference in performance
> between 4.2.5 and 5.0 - it's probably worth taking a look at the
> discrepancies.

The discepancies are on the mandelbrot benchmark. The same
discrepancies can be observed between different runs of the benchmark
on 5.0, even using the same compiled bytecode of the benchmark; about
10-20% of the time, for no apparent reason, that benchmark would take
twice as long as usual. I observed this random behavior on 5.0, but I
don't know if it appeared on 4.2.5 as well.

That random behavior seems to be linked to the use of safe flonum
operations (fl+ and co.) since changing the benchmark to use either
generic arithmetic operations or unsafe float operations makes the
running times of the benchmark consistent. I told Matthew about that.

I've been working on typed versions of these benchmarks, and some are
faster than the untyped versions (including the mandelbrot benchmark,
whose typed version is ~30% faster and does not show the random
behavior discussed above). I'll push them later today, and some could
be worth using on the shootout.


Posted on the dev mailing list.