core dumps in optimized case with gcc 3.0 and 3.0.1 (regressiona gainst 2.95)

[Andreas Jaeger]

"Nuesser, Wilhelm" <wilhelm.nuesser@sap.com> writes:

> Hi,
>
> when compiling our software ( binary size approx. 40 MB) with gcc 3.0 and
> 3.0.1 with -O2 on
> 	Linux ia32, 
> 	RedHat 6.2 and SuSE 7.0 (i.e. glibc 2.1.3),
> 	kernel 2.2.19 and 2.4.4
> we find core dumps which do not appear when compiling with 2.95.[2,3] 
> (with or without optimization) or with gcc 3* without optimizations.
>
> We suspect gcc bugs, since our software run on many 32 and 64 bit platforms,
> but - of course -
> we are not sure. We have no idea what is actually going on so we can not
> produce any testcase
> at the moment.

I would play around with the various compiler flags and check whether
one of the new optimizations causes the problem.

A usual suspect is that your program breaks the strict aliasing rules,
I would try -fno-strict-aliasing first.

Andreas
-- 
 Andreas Jaeger
  SuSE Labs aj@suse.de
   private aj@arthur.inka.de
    http://www.suse.de/~aj