Re: Bug#1067907: flam3-utils: flam3-genome randomly segfaults on ppc64el

Hello Peter,

> Thanks for looking at this.
> Does it run consistently at -O1?
> (At -O3, sometimes it works, sometimes it doesn't)

  You are right, I tested using your script, and the program crashes 
randomly.

> I should have mentioned earlier,
> I have a little test script, that I attached to #1001667
> 
> A run of a minute or two would suffice to show any issues.
> 
> Would be interesting to know what happens with -O2,
> as I like to use the highest optimisation that is stable.
> 
> Wondering whether this really is a bug in gcc...

I tried multiple approaches and found that reducing the optimization 
level from -O3 to -O2,-O1 does not resolve the segmentation faults.

However, when I removed only the -ffast-math flag (while keeping other 
optimizations) from Makefile.am, the program ran consistently without 
any segmentation faults.

This seems to indicate that the instability is likely related to the 
-ffast-math flag, rather than the optimization level itself.


Thanks Trupti