title: GAS does not recognise register %ip
body: <p>In my 16bit program GAS is balking at the instruction:</p>
  
  <pre><code>movw %ip, %dx
  </code></pre>
  
  <p>I find this strange as moving a segment register works fine, for example:</p>
  
  <pre><code>movw %ss, %ax
  </code></pre>
  
  <p>The full error message is:</p>
  
  <blockquote>
    <p>Error: bad register name `%ip'</p>
  </blockquote>
  
  <p>And my version string is:</p>
  
  <blockquote>
    <p>GNU assembler (GNU Binutils) 2.22</p>
  </blockquote>