Using C++ what happens on certain shift operations depends on if the variable is a signed or unsigned type (<< - Arduino Reference) If one is programming in AVR assembly language then you do have access to a carry and/or overflow bit that is effected by certain machine language shift and rotate instructions.
Lefty
I think this is what I am looking for. I think I need to delve into the AVR ASM stuff to get what I want. It must be possible. If its faster or not, not sure.
Thanks.