Shifts the bits of the destination operand to the {direction}. Two forms: (1) as<d> Dx/Im, Dn shifts Dn by the count in Dx or immediate (1–8), any size. New bits are filled with the sign bit. Defaults to word. Note: ASL sets the overflow flag if the MSB changes during the shift, while ASR always clears it. (2) as<d> (An) shifts a memory word by 1, no size suffix allowed.