Re: Numerical Computation and Ada95

[Ted Dennison<dennison@telepath.com>]

In article <9dd9tb$1o56$1@ulysses.noc.ntua.gr>, N&J says...
>From what you said I undestand that nobody has ever compared Ada's timing
>performance with Fortran77/90/95, C and C++ in programs that require lots of
>arithmetic and logical operations (perhaps FFT). I think I will try to do it
>when I learn Ada95 better

Again, you *can't* make such a comparison. The best you can do is compare
*implementations*, which have way more variables than just the source language.

Suppose I took my super-optimizing RTOS Ada compiler, compared it to the
(mythical) $50 HappySoft Win95 Fortran compiler for students, and discovered
that Fortran was %50 *slower*. What exactly would I have proved? Only that
HappySoft doesn't care about optimization as much as the authors of my Ada
compiler. 

If you are wondering about *theory*, theoreticly Ada (with the checks turned
off) ought to be exactly the same speed for arithmetic and logical operations as
C, C++, and Fortran before optimization, and the same speed or *faster* than any
of them after optimization, due to the extra info that can be fed to the
optimizer. But theory won't get you far in the Real World.

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