title: Is there a quick way to "git diff" from the point or branch origin?
body: <p>I have looked at various SO answers on using <code>git diff</code> and git revisions (HEAD, ORIG_HEAD, FETCH_HEAD, etc.) and I still haven't found an easy way to list the changes have been made since the beginning of the local branch, or since last rebase.</p>
  
  <p>By <em>easy</em> I mean without having to look up and paste commit SHA or having to count how many commits I want to look back.</p>
  
  <p><code>git diff origin/master</code> is close, but it refers to remote which may have diverged since I checked out new branch from it. </p>
  
  <p>I would expect something like <code>git diff BASE_HEAD</code> to be available.</p>
  
  <p>...unless there's already a way to do that. Does anyone have the answer?</p>