public int compareTo(Instruction instr) {
		if (addr != instr.addr)
			return addr - instr.addr;
		if (this == instr)
			return 0;
		do {
			instr = instr.nextByAddr;
			if (instr.addr > addr)
				return -1;
		} while (instr != this);
		return 1;
	}