[vox-tech] float vs double, int vs short

[MAPSp@dirac.org (Peter Jay Salzman)]

I've been googling for the past 15 minutes and have read that:

   * computations with doubles are always faster than floats
   * computations with doubles are often faster than floats
   * computations with floats are often faster than doubles
   * computations with floats are always faster than doubles

The arguments I've read for all four cases seem reasonable.  I trust the
collective brains of lugod more than any internet forum.  What's the real
scoop on the relative speed of basic arithmetic operations on floats and
doubles?

The platforms I'm mostly concerned with are 32 and 64 bit x86 running
Windows and Linux using Java and C++.

I'm also interested in the relative speed of shorts vs ints.  I've heard
that ints are almost always faster (with the "usual" width of an int in C,
since an int and short may have the same width on a given platform) due to
word alignment issues.

I did my own test of taking averages of a large number of numbers in C with
shorts and ints on Cygwin on WinXP.  The results were pretty inconclusive.

I know this is a pretty complicated topic; if anyone can comment on it, I'd
really appreciate it!

Thanks!
Pete
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