optimize integer_divide because the tests spent a lot of time in it
optimize integer_divide because the tests spent a lot of time in it

mamazu/Lpg,mamazu/Lpg,TyRoXx/Lpg,TyRoXx/Lpg,mamazu/Lpg,TyRoXx/Lpg,TyRoXx/Lpg,mamazu/Lpg,TyRoXx/Lpg