[fpc-pascal] Dynamic arrays performance test.

Florian Klaempfl florian at freepascal.org
Wed Mar 2 07:29:21 CET 2005

Agustin Barto wrote:

> I ran some test of serveral Extended matrix internal representations
> to implement on an adaptation of Jedi_Math's matrix code (already
> contributed some of this modifications). In the attached file you'll
> see one of these tests. I have some questions about the results:
> * The performance of the three internal structures is virtually the
> same. Which one do you think is the best?
> * The program compiled with fpc 1.9.8 (on Linux) is two times slower
> than the one compiled with Delphi 7 (on Windows). Do you know what can
> I do to improve the performance with fpc?

- use double instead of extended
- compile with -Cfsse2 on P4 CPUs
- FPC's random is probably more complex
- Test on _real_ world programs rather than on synthetic tests which allows 
compilers to cheat. We don't spend our time in useless optimizations as your 
inner loop requires because it don't help in properly written programs.

More information about the fpc-pascal mailing list