https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84816
--- Comment #6 from Dmitry Lesnikov <dlesnikov at hotmail dot com> --- (In reply to Andrew Pinski from comment #5) > (In reply to Dmitry Lesnikov from comment #4) > > (In reply to Andrew Pinski from comment #1) > > > signed overflow is undefined behavior at runtime. > > > > for(int i=0; i<10; i++) > > > > this loop is correct. > > But there is an overflow with the variable a when i is 6. Yes, but code generation incorrect. It's not runtime yet.