title: Proper way to subtract two 64 bit numbers in x86 assembly
body: <p>I'm using a 32 bit system and have a 64 bit number saved in EDX:EAX. I'm trying to subtract a number saved in ESI:EDI is this correct? I'm pretty sure its not because after 3 iterations the results are incorrect.</p>
  
  <pre><code>sub %esi, %edx          #Subtract two 64 bit numbers
  sub %edi, %eax
  </code></pre>