ENH: Expose bit_count ufunc equivalent to the scalar methods #16325
Description
Modern CPUs have a builtin popcount instruction that counts the number of 1 bit in an unsigned integer. It would be great if numpy has a routine that exposes this operation.
Both GCC and MSVC have builtin functions for this instruction.
Possible usage:
>>> np.popcount(4)
1
>>> np.popcount(np.arange(5, dtype=np.uint))
array([0, 1, 1, 2, 1])