COMPUTTER HARDWARE INSTRUCTION AND METHOD FOR COMPURING POPULATION COUNTS

摘要

The present invention relates to a method and apparatus for computing a large bit string population count and uses a carry-save adder to reduce the time it takes to calculate the population count of operands in registers. The carry-save adder is essentially faster than the full adder used in the prior art because it does not propagate the carry. The novel operand method for calculating the partial population counting is performed by dividing the operand bit string into smaller blocks. This small fractional population counting takes much less time to compute than the complete population counting on the entire operand bitstream.