count

Count bits set.

Similar: count, parity.

count(x)
// x: an int32

const xbit = require('extra-bit');

xbit.count(7);
// → 3 (111 ⇒ 3)

xbit.count(12);
// → 2 (1100 ⇒ 2)

xbit.count(63);
// → 6 (111111 ⇒ 6)

References

• Parallel method: Bit Twiddling Hacks
• bit-twiddle: @mikolalysenko
• count-bits: @DenQ
• popcnt32: @emilbayes