Hmm, it isn't necessary to restrict this optimization AFAICS. We have just two cases.
(~X & Y) -> X < Y (X & ~Y) -> Y < X (~X | Y) -> X <= Y (X | ~Y) -> Y <= X is true for unsigned 1-bit types. For signed 1-bit types we need to invert logic here as following: (~X & Y) -> X > Y (X & ~Y) -> Y > X (~X | Y) -> X >= Y (X | ~Y) -> Y >= X Btw there is one optimization in this context which might be something worth here too. -X -> X for 1-bit typed X (signed doesn't matter here). Kai
