Efficient Hamming Weight Comparators for Binary Vectors Based on Accumulative and Up/Down Parallel Counters

New counting-based methods for comparing the Hamming weight of a binary vector with a constant, as well as comparing the Hamming weights of two input vectors, are proposed. It is shown that the proposed comparators are faster and simpler, both in asymptotic sense and for moderate vector lengths, compared with the best available fully digital designs. These speed and cost advantages result from a more efficient population counting, as well as the merger of counting and comparison operations, via accumulative and up/down parallel counters.