----- Original Message -----
From: "Adriaan van Os" <[EMAIL PROTECTED]>
To: "FPC developers' list" <fpc-devel@lists.freepascal.org>
Sent: Thursday, November 03, 2005 10:48 AM
Subject: Re: [fpc-devel] OpenGL and glut bugs in Freepascal 2.1.1runningwith
Mac Os X Tiger ?
Nexus wrote:
<snip>
An unhandled exception occurred at $903E68B8 :
EInvalidOp : Invalid floating point operation
<snip>
So it first seems to be some error in the fpu code generation of the
compiler. But the strange things is, after running a C-Program which uses
glut and open gl everything just works fine. So maybe there is something
wrong in the open gl / glut initialization part or some incompatibilities
with Mac OS X 10.4
<snip>
Just a guess - could this be the same problem as discussed in the
"[fpc-devel] MacOSX: EXC_ARITHMETIC in PerformHIConversion" thread, where
Jonas Maebe wrote:
Are these exceptions by default disabled by gcc ?
The FPC runtime explicitly turns them on by default (since they are
required for detecting errors), while libc doesn't. It is independent
of the compiler used.
So, if I understand it correct, you wont get a aritmic exeption in FPC
anymore when this is turned on ?
The "invalid fpu operation" exceptions are turned on in the FPC system
unit initialisation code. If you add the code I posted, they are turned
off again and so you won't get them (not due to buggy code in the Carbon
framework and not anywhere else either).
Regards,
Adriaan van Os
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Thank you very much for your help (all of you).
You were absolutely right. It seems to be the same problem as discussed in
the "[fpc-devel] MacOSX: EXC_ARITHMETIC in PerformHIConversion" thread.
I ran the programs with Mac OS X 10.3 and they were running just fine. They
just crash with Mac OS X 10.4.x.
It seems to be the same bug in the Carbon framework under Mac OS X 10.4.x
mentioned in this thread, which causes to generate invalid floating point
operation exceptions in some cases. By disabling these exceptions as
mentioned in the EXEC_ARITHMETIC thread with
asm
mtfsfi 6,1
end;
everything works now with Mac OS X 10.4 as it should.
But two questions remain:
1.) Why are the fpc applications running fine after running some open gl
applications written in c ? (maybe i didn't get it yet, sorry)
2.) It does not sound very safe to turn of the floating point exceptions
forever (or at least until Mac OS X 10.5). Is there any possibility to
create some clean workaround without needing the divine intervention of the
apple fixing the carbon libs in 10.4 ?
Thanks again
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