A data processing apparatus and method are provided for performing a shift function on a binary number. The apparatus comprises count determination circuitry for determining a number of contiguous bit positions in the binary number that have a predetermined bit value, the count determination circuitry outputting a count value indicative of the number of contiguous bit positions determined. In parallel with the operation of the count determination circuitry, coarse shifting circuitry is used to determine, for at least one predetermined number of contiguous bit positions, whether that predetermined number of contiguous bit positions within the binary number has said predetermined bit value. An initial shift operation is then performed on the binary number based on that determination in order to produce an intermediate binary number. Once the count value is available from the count determination circuitry, fine shifting circuitry then performs a further shift operation on the intermediate binary number, based on the count value output by the count determination circuitry, in order to produce the result binary number. This provides an efficient mechanism for performing a shift function on a binary number, while still capturing the count value from the count determination circuitry.