Count trailing zeros

The ctz instructions, short for count trailing zeros, are used to count the amount of zeros at the end of the numbers binary representation.

Try it

Syntax

wasm

;; load a number onto the stack
i32.const 8388608 ;; 00000000_10000000_00000000_00000000

;; count trailing zeros
i32.ctz

;; the top item on the stack will now be 23
Instruction Binary opcode
i32.ctz 0x68
i64.ctz 0x7a