http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57199
--- Comment #4 from Paul Pluzhnikov <ppluzhnikov at google dot com> --- (In reply to Jakub Jelinek from comment #3) > it can't prove the following loop that uses _8 as upper bound is dead, ... Do we need a separate "may invoke undefined behavior" warning? In our codebase of 100+ million lines of C++, we've found ~20 instances of real "invokes undefined behavior" (so we don't want to turn the -Waggressive-loop-optimizations off). But we also have ~5 instances where the warning is bogus, and there is no easy way to turn them off, short of sprinkling -Wno-aggresive-loop-optimizations over our BUILD files.