Population count

The popcnt instructions, short for population count, are used to count the amount of 1s in a numbers binary representation.

Try it

wasm

;; load a number onto the stack
i32.const 130 ;; 10000010

;; count the 1s
i32.popcnt

;; the top item on the stack will now be 2

Instruction	Binary opcode
`i32.popcnt`	`0x69`
`i64.popcnt`	`0x7b`