[fpc-devel] FPC 2.0.0 vs FPC 2.0.2 (div by zero)

Michalis Kamburelis mkambi at poczta.onet.pl
Thu Mar 9 04:12:10 CET 2006


(Second send, it seems that mails from my old email address do not reach 
fpc lists)

Den Jean wrote:
> Hi,
> 
> I have a strange problem. My Qt4 demo program worked 
> fine with FPC 2.0.0, but crashes (div by zero) with FPC 2.0.2.
> Debugging shows that indeed a div by zero is done within
> the Qt4 lib. However with FPC 2.0.0 or using C++ code the library
> isn't bothered with the div by zero. When I use FPC 2.0.2 however
> it is.
> 

Maybe it was FPC 2.0.0 bug (that was fixed in the meantime) that caused
this SIGFPE inside qt to be ignored ? AFAIK it was always the intention
of FPC that if used library causes a signal like SIGFPE, this signal
*will not be ignored* and will cause our program to fail with some
exception.

Maybe you can workaround this with Set8087CW, just like it has to be
workarounded for OpenGL under Windows (see
[http://www.freepascal.org/bugs/showrec.php3?ID=3955]). Just add
"Set8087CW($133F);" at the beginning of your program (or even right
inside qt unit initialization) and see if it helps.

(Note that I'm writing this without any knowledge of qt or your testcase
--- I just thought that it may be helpful, sorry if it's not relevant :) ).

Michalis



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