title: What is this x86 inline assembly doing?
body: <p>I came across this code and need to understand what it is doing. It just seems to be declaring two bytes and then doing nothing...</p>
  
  <pre><code>uint64_t x;
  __asm__ __volatile__ (".byte 0x0f, 0x31" : "=A" (x));
  </code></pre>
  
  <p>Thanks!</p>