PHP多个连续空格回车替换为一个，怎么写更简短

<br /><br />function re($content)<br />{<br />    /* return preg_replace('/(<br\s*\/?>){3,}|( ){3,}/i'),'\\1',$content); */ //错误！<br />    /* return preg_replace('/(<br\s*\/?>| ){3,}/i'),'\\1',$content); */ //错误！<br />    return preg_replace(array('/(<br\s*\/?>){3,}/i','/( ){3,}/i'),'\\1',$content);<br />}<br /><br /><br />//test<br />$content = '1111    <br><br><br><br />@@@<br/><br><br/><br>aaaaM<br><br/>';<br />echo re($content);<br />exit();<br />