1. A method, implemented in logic, of converting a normalized n-bit value into a normalized m-bit value in accordance with a predetermined rounding mode, the method comprising: receiving the normalized n-bit value at the logic; determining an initial m-bit value, wherein the bits of said initial m-bit value are determined to be equal to the m most significant bits of a concatenation of one or more copies of a group of one or more bits derived from the received normalized n-bit value; based on bits of the normalized n-bit value and in accordance with the predetermined rounding mode, selecting an output state indicating how the normalized m-bit value is to be determined from the initial m-bit value; in accordance with the selected output state, determining the normalized m-bit value to be equal to one of a plurality of candidate m-bit values, the plurality of candidate m-bit values consisting of the initial m-bit value and at least one of: (i) the initial m-bit value incremented by one, and (ii) the initial m-bit value decremented by one; and outputting, from the logic, the determined normalized m-bit value.