[Bug tree-optimization/100115] Bogus -Wmaybe-uninitialized warning with -O3

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100115

--- Comment #3 from Martin Sebor <msebor at gcc dot gnu.org> ---
The reason why the warning tends to disappear in a simpler test case is because
of the limit (I just had it happen with my reduction).  Don't spend more time
on it than you already have, I'll work with the attached translation unit.  The
warning is exquisitely sensitive to optimizations so when GCC doesn't optimize
something in a way that lets it prove the uninitialized read is impossible, it
triggers.  I'm hoping to improve this for GCC 12.