[erlang-questions] how to do faster integer operations (was: some language changes)

Matthias Lang <>
Thu Jun 7 08:58:04 CEST 2007


Paul Mineiro writes:

 > It's been a good lesson to discover that using less than the full machine
 > width for integers leads to significant speed up.  Is there a FAQ for
 > performance where this kind of knowledge is accumulated?

I've shied away from putting optimisation tricks in the FAQ. Taking
the current information as an example, I could write something like:

  Q: I have some limited-width-integer-intensive code which I want
     to speed up, what do I do?

  A: If the integer width is within a few bits of 32 bits and you're
     running on a 32 bit CPU, try moving to a 64 bit machine.

It doesn't seem like a _frequently_ asked question, it's terribly tied
to the state of hardware right now, and, last but not least, I find it
hard to get excited about a radical speedup which improves things to
"only" 10x slower than the straightforward answer, which is "do it in C".

I'm still secretly hoping that someone will find neat improvement.

Matthias



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