2 popcnt - number of bit that match a given value
8 x number (real or integer)
14 Count the number of bits in abs(x) that match bitval. The default
15 bitval is 1 which counts the number of 1 bits.
17 The popcnt function is equivalent to #x when x is an integer.
20 > print popcnt(32767), popcnt(3/2), popcnt(pi(),0), popcnt(pi(),1)
23 > print popcnt(randombit(128), 0), popcnt(randombit(128), 1)
30 long zpopcnt(ZVALUE z, int bitval)