Design of an optimized reversible bidirectional barrel shifter

In this paper, we propose an optimized design of an n-bit reversible bidirectional barrel shifter, where n is an integer power of two. The proposed bidirectional barrel shifter can shift at most (n − 1) bits using logn bits select input whereas the existing reversible barrel shifters can shift at most logn bits using the same number of select inputs. The proposed reversible barrel shifter is divided into three components and a generalized approach is presented for each component to realize the whole architecture. A comparative analysis has been presented to show the significant improvement of our proposed design with respect to the existing approaches in terms of numbers of gates, garbage outputs and quantum cost.