[Bug rtl-optimization/68755] [4.9/5 Regression] wrong code at -O3 on x86_64-linux-gnu

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68755

--- Comment #11 from Richard Biener <rguenth at gcc dot gnu.org> ---
It might help if we transform such "obvious" out-of-bound accesses to
__builtin_trap (or unreachable even).  Not too early of course beacuse
then we lose -Warray-bound diagnostics.