https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115345
--- Comment #12 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to Djordje Baljozovic from comment #11) > (In reply to Djordje Baljozovic from comment #9) > > (In reply to Andrew Pinski from comment #7) > > > A few questions, does `-fsanitize=undefined -fsanitize=address` report > > > anything? Does it work at -O0 and not just -O3? Does adding > > > -fno-strict-aliasing to the command line "fix" the crash? Are there any > > > warnings with `-Wextra -Wall` that might be causing an issue? > > > > Have not tested -O0 and -fno-strict-aliasing; will let you know if this > > fixed the problem. > > No warnings with -Wextra -Wall to my knowledge. > > > > Sincerely, > > George > > Hi Andrew and Jakub, > The results are more than interesting: > > 1. -fno-strict-aliasing: none of the inputs processed (with O3) > 2. O0: all but one input processed > 3. O3: none of the inputs processed > 4. O1 and O2: all inputs processed without any issues -- this did it. > > Now the question is: how on Earth did O1/O2 do the trick, and not O0?! Can you check whether -O0 works with the other compilers? It feels like you might be triggering some undefined behavior in your code. If you have a short running example that breaks with -O0 it might be also interesting to run it through valgrind to spot use-after-free or uninitialized use issues. > Once again, thanks a lot for your detailed and quick responses. > George > P.S. I will keep @Jakub's bisect idea in mind if something like this happens > in the future.
