On 17/11/2015 17:54, Laszlo Ersek wrote: > I'm not worried. I hate it for the mental load it represents. > > For me, the fact that the negative sign is encoded (with *any* kind of > representation) within the bit pattern subject to shifting, makes the > negative sign *inherently* incompatible with shifting. > > In real life, *you don't shift a sign*. It just makes no sense. The sign > is not a digit. You can append or cut off zeroes from the right, but the > sign is not subject to that. The sign doesn't care.
I agree. That's why I said elsewhere that it's *okay* for me if e.g. 0xC0000000u << 2 is undefined behavior. In fact, it's mostly okay for me if shift _into_ the sign bit were undefined behavior. Basically, I avoid the "mental load" with a rule that left shift is just multiplication by 2^N. Paolo
