[Bug tree-optimization/106922] [12 Regression] Bogus uninitialized warning on boost::optional<<std::vector<std::string>>>, missed FRE

["jan.zizka at nokia dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106922

--- Comment #18 from Jan Žižka <jan.zizka at nokia dot com> ---
Created attachment 53617
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53617&action=edit
Third reproducer failing with 9baee6181b4e427e0b5ba417e51424c15858dce7

I did cherry-pick 9baee6181b4e427e0b5ba417e51424c15858dce7 on top of
5edf02ed2b6de024f83a023d046a6a18f645bc83 and gcc 12 and I confirm that the
second reproducer works with this. But unfortunately our production code still
fails.

Sorry that I cannot provide better more reliable reproducer, but our production
code is complex and I try to bump it to smallest snippet which still fails. I
can try to refactor our production code somehow to remove all proprietary stuff
but that might take some time.

I have created new reproducer, this time it fails both with boost::optional and
with std::optional. In the reproducer I have commented lines which will cause
the warning to disappear when removed. There is additional int in the structure
which needs to be there and also the assignment needs to be repeated in the
loop.