public Object[] ic_trans(IcFun f,IcStmt_label break_to){
		LinkedList<IcStmt> codes = new LinkedList<IcStmt>();
		
		/* 1.expr */
		Object[] result = expr.ic_trans(f, break_to);
		codes.addAll((LinkedList<IcStmt>)result[0]);
		IcOper r = (IcOper)result[1];
		/* 2.neg */
		IcVar_tmp t = IcVar_tmp.new_one(f);
		codes.add(new IcStmt_op(f,0,t,new IcConst_int(0),r,IcStmt_op.MINUS));
		
		return new Object[]{codes,t};
	}