Re: Bug#1067907: flam3-genome segfaults on ppc64el with -ffast-math enabled

On 2025-07-31 22:53, Peter Blackman wrote:
> On 30/07/2025 21:05, Trupti wrote:
>> 
>> 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.
> 
> 
> Interesting!  I was not expecting -ffast-math to be the cause of the 
> trouble.
> 
> Attaching a rules file to use clang. (Clang seems to break dwz!)
> 
> If you are happy to try this, it would show if the problem is with gcc.
> If the build works with clang with -ffast-math enabled,
> I will raise a bug against gcc for this.


Thanks for suggestion.
Yes, I tested the build using Clang with -ffast-math enabled, but 
unfortunately the genome.sh test still results in a segmentation fault 
when run in a loop.

I will once again debug the issue using the gdb tool to get more 
clarity.Any additional insights or suggestions are most welcome.

Best Regards,
Trupti