lw	0	8	neg1	load reg8 with -1
	lw	0	5	four	load reg5 with 4
	sub	5	8	6	reg6 <- reg5 - reg8 (reg6 <- 5)
	addi	5	3	4	reg3 <- reg5 + 4  (reg3 <- 8)
	andi	3	5	248	reg5 <- reg3 & 0xf8  (reg5 <- 8)
	add	5	8	5	reg5 <- reg5 + reg8 (reg5 <- 7)
	sw	0	5	store
	noop
done	halt
neg1	.fill	-1
four	.fill	4
store	.fill	0