Design of a reversible bidirectional barrel shifter

Abstract

Reversible logic has promising applications in the field of quantum computing, optical computing, low power computing, and other emerging computing technologies. A barrel shifter that can shift and rotate multiple bits in a single cycle is an important component of many computing units. This paper presents the reversible design of bidirectional arithmetic and logical barrel shifter. The proposed design consists of the reversible Fredkin and Feynman gates. The Fredkin gate used in the design of reversible bidirectional arithmetic and logical barrel shifter can implement the 2∶1 MUX with minimum quantum cost, minimum number of ancilla bits and minimum number of garbage outputs while the Feynman gate is used to avoid the fanout as fanout is not allowed in the reversible logic. The design is evaluated in terms of number of garbage outputs, quantum cost and number of ancilla bits.