Control dependency between prior load in while condition and later store?

[Daniel Jordan]

A question for memory-barriers.txt aficionados.

Is there a control dependency between the prior load of 'a' and the 
later store of 'c'?:

  while (READ_ONCE(a));
  WRITE_ONCE(c, 1);

I have my doubts because memory-barriers.txt doesn't talk much about 
loops and because of what that document says here:

  In addition, control dependencies apply only to the then-clause and
  else-clause of the if-statement in question.  In particular, it does
  not necessarily apply to code following the if-statement:

        q = READ_ONCE(a);
        if (q) {
                WRITE_ONCE(b, 1);
        } else {
                WRITE_ONCE(b, 2);
        }
        WRITE_ONCE(c, 1);  /* BUG: No ordering against the read from 'a'. */

It's not obvious to me how the then-clause/else-clause idea maps onto 
loops, but if we think of the example at the top like this...

  while (1) {
      if (!READ_ONCE(a)) {
          WRITE_ONCE(c, 1);
          break;
      }
  }

...then the dependent store is within the then-clause.  Viewed this way, 
it seems there would be a control dependency between a and c.

Is that right?

Thanks,
Daniel