surprising result with hipe compilation
Ulf Wiger (AL/EAB)
Wed Nov 5 17:51:15 CET 2003
From: Kostis Sagonas [mailto:kostis@REDACTED]
>Ulf, I have looked at your program and have trouble obtaining
> the behaviour that you are observing. When compiled to native
> code, the code is consistently 20-40 % faster than BEAM (and
> arguably more than that).
This is interesting.
> Some more comments:
> - The benchmark reads data from a file which is handled as a stream
> Performing I/O can be give a big flactuation in times. Ideally,
> the benchmark should be re-written so that the data is read once
> from the file (converted to a list or binary), and the time to
> process the data is reported.
True. I decided not to do that, since the measured differences
were large enough that they couldn't be blamed on file.erl.
Interestingly, your figures are equally consistent, but in the
> - timer:tc is NOT the best possible way to measure time;
> ideally, some more accurate time measurements should be used.
I think timer:tc is Ok, as long as the job is significantly large,
or one runs enough iterations. In this case, I wasn't really
interested in any differences smaller than, say, 20%.
I will pretend that this didn't happen for now, unless you want
to come visiting and perform your own measurements on my particular
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