On Wed, 28 Jul 2004 04:22:39 EDT, "acasta" <acastagnini AT yahoo DOT com>
wrote:
> I've tried to compile PovWin with MinGW 3.3 (gcc 3.2.3).
> I had to comment out a couple of functions from pvupdate.cpp (reg_printf and
> GetInstallTime) because of error messages complaining about redefinition.
> (I didn't try to investigate this more deeply).
> After this, I obtained a working pvengine.exe.
>
> Rendering a sample scene with this compiled-by-me version takes about 90'',
> while with the official executable rendering time is about 30''!

What's comparison between rendering times under MinGW GUI and MinGW console
builds ?

> Now, I know from reading some posts in this group that the POV team uses the
> Intel compiler, that produces very fast executables, but a difference of
> three times seems a bit strange to me.

BTW, I did not tried it myself but there is free console version of VisualC
somewhere at Microsoft site. You could optionally try it.

> Can you tell me whether this is just what you expect from these compilers or
> I should adjust optimisation options differently?

The difference in speed is "a little" large but OTOH note POV-Ray is threading
software with exception handling. I do not know how GCC of MinGW handles
threads and exceptions in details but there can be source of difference.

> Can you give me suggestions about what optimisations I should use?

I never focused the optimisations under MinGW but I imagine you could find
some help within povray.unix group since they are more experienced in
optimisations of GCC.

ABX

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