Audits Google Chrome - Control and elements must have labels

Question

I checked the Audits of Google Chrome and alarmed in accessibility that my inputs do not have labels, but esotu using placeholder, what do you think? I believe that this mistake accused is not real, what do you think?

<div class="col-md-6">
<input name="name" type="text" id="name" size="30" value="" placeholder="Nome"/>
<br />
<input name="email" type="email" id="email" size="30" value="" placeholder="Email"/>
<br />
<input name="phone" type="text" id="phone" size="30" maxlength="13" onKeyUp="javascript:somente_numero(this);" onkeypress="formatar_mascara(this,'## ####-#####')" placeholder="Telefone"/>