# counting_bits.asm
	
.data
.text
.global main
main:
    mov $0xA3, %ebx # value to count bits in
    mov $0, %ecx    # bit counter
check_zero:
    cmp $0, %ebx    # done? (that is, no more bits)
    je done
    mov %ebx, %edx  # lsb of %ebx set?
    and $0x01, %edx
    jz lsb_is_zero
    add $1, %ecx    # if so, count it
lsb_is_zero:
    shr $1, %ebx    # shift off the bit just counted
    jmp check_zero  # try next bit
done:
    mov %ecx, %eax
    ret