pub mul_low:
	mov r3, 0 ; result
	mov r4, 31 ; loop counter
	
	mull_loop:
		asr r5, r2, 31
		and r5, r5, r1
		lsl r5, r5, r4
		add r3, r3, r5
		lsl r2, r2, 1
		sub r4, r4, 1
		cmp r4, 0
		jge mull_loop
	mov r1, r3
	
	jmp r13