[Bug tree-optimization/66868] [5/6 Regression] wrong code generated with -O3 (dead code removal?)

[doko at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66868

--- Comment #2 from Matthias Klose <doko at gcc dot gnu.org> ---
the testsuite passes with -fsanitize=undefined (no additional output) and both
-fsanitize=undefined -fsanitize-undefined-trap-on-error doesn't abort either.