Digit-set conversions: generalizations and applications

The problem of digit set conversion for fixed radix is investigated for the case of converting into a non redundant, as well as into a redundant, digit set. Conversion may be from very general digit sets, and covers as special cases multiplier recodings, additions, and certain multiplications. We generalize known algorithms for conversions into non redundant digit sets, as well as apply conversion to generalize the O(log n) time algorithm for conditional sum addition using parallel prefix computation, and a comparison is made with standard carry-lookahead techniques. Examples on multi-operand addition are used to illustrate the generality of this approach. O(1) time algorithms for converting into redundant digit sets are generalized based on a very simple lemma, which provides a framework for all conversions into redundant digit sets. Applications in multiplier recoding and partial product accumulation are used as exemplifications