Comment # 12 on bug 1133245 from Dr. Werner Fink

(In reply to Martin Li��ka from comment #10)
> (In reply to Dr. Werner Fink from comment #8)
> > Hmm ... the transformation might be correcti(?), but how should libsigsegv
> > catch the first segmentation fault (and only this), if the check is moved in
> > the resulting assembler instructions out of the way?  Would the volatile
> > attribute for handler_called help here?
> 
> I would recommend to use a memory barrier:
> asm volatile("" ::: "memory");
> 
> More informations:
> https://stackoverflow.com/questions/14950614/working-of-asm-volatile-memory
> 
> > 
> > Btw: IMHO we need an HOWTO for debugging link time optimized programs within
> > gdb. This because with LTO the core dumps from users/customers become rather
> > useless (IMHO).

Ouch .. this is somehow a d��j�� vu for me as I had in past (15 years back) used
memory barriers very often but had been told that this not need anymore with
the modern gcc.

IMHO it is a bug of the compiler if code is moved in such a way that the logic
becomes broken.