title: Moving register content to memory address in another register in x86_64
body: <p>Doing some inline assembly in clang (basically guessing my way through by using various references) and I'm trying to move the contents of <code>%rdi</code> to the address pointed to by <code>%rdx</code>. However none of my syntax works, this:</p>
  
  <pre><code>mov %rdi, ptr %rdx
  </code></pre>
  
  <p>gives:</p>
  
  <pre><code>error: expected relocatable expression
  </code></pre>
  
  <p>What's wrong? What is the syntax in inline assembly in clang to do this? Thanks.</p>