Abstract
Bit-counting refers to the operation of counting the number of "1"s in a given computer word or binary vector. Currently there are several algorithms to solve this problem. The simplest one is serial shifting. Many recent algorithms have evolved in the last few years to overcome the slowness of serial shifting. However, their performance behaviour was not studied deeply. In this paper, the performance behaviour of existing algorithms will be investigated with clarifying comments. Moreover, an enhanced lookup table algorithm that is faster than the existing algorithms is presented and evaluated.