[fpc-devel] Anyone an idea were/how to look for the missing merge in 3.0.2

[Pierre Muller]

Le 09/06/2021 à 00:31, Martin Frb via fpc-devel a écrit :
> I have the following issue.
> 
> A testcase (LazDebuggerFp/test) works fine. Except for 3.2.0 and 3.2.2 (win 64) with -O3 or -O2
> 
> In detail:
> - It works in 32 bit   3.2.2     --  O3
> - It works in 64 bit  3.0.4 / 3.3.1  -- O1 O2 and O3   (My 3.3.1 is 2 weeks old.)
> - It works in 64 bit  LINUX  3.2.2     --  O3
> - It works in 64 bit   3.2.0 / 3.2.2  -- O1
> - It works in 64 bit   3.2.2  -- O3  with {$implicitexceptions off} in several units
> 
> * It does not work in 64bit  3.2.0 / 3.2.2  -O2 or O3  with default {$implicitexceptions ON}
> 
> Yes, it could be a bug in my code, but at this point, my primary suspicion points to a different origin for the trouble.
> 
> I could not find the faulty code yet. I suspect that it is a random memory write (dangling pointer) that causes an error long after.
> And  given that I can't use valgrind....
> 
> So anyone can thing of any bug fixed (as it works with 3.3.1), that may not have been merged?
> I have not checked 3.2.1 yet. / Will be a while, I am away a couple of days.

   Martin,

could you check if this relates to bug #38973?

https://bugs.freepascal.org/view.php?id=38973

  This bug also does not show in current trunk.

  If you get the same pattern of failures, it is most probably related to this wrong optimization.


Pierre