https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81110
--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Ada Liu from comment #5) > But (65536*d[1]+d[0]) is convered to (unsigned long), should not be treated > as unsigned？ NO. Both C and C++ language is clear here about the expression "65536*d[1]" is done in signed int. > On gcc4.7.2 I can get expected result. Yes but newer gcc optimizes more and uses the fact that signed integer overflow is undefined behavior more.
