int reg = item1.getRegisterNumber(); if (reg < 0) return false; return stack.getLastUpdate(reg) < branchTarget;
return false;
	private boolean constantSince(Item item1, int branchTarget) {		if (item1.getConstant() != null)			return true;		int reg = item1.getRegisterNumber();		if (reg < 0)			return false;		return stack.getLastUpdate(reg) < branchTarget;	}