micro-optimizing loops (was Help with casts)

[Dan Bernstein]

What Chris doesn't point out is that

  i = blah;
  do
   {
    ...
   }
  while (--i);

will compile to the optimal code on most machines under most compilers,
whether they have condition codes or not, whether they have exposed jump
delays or not, and whether the optimizer is on or off. I don't know any
machines where this will produce worse code than any other expression of
the loop.

---Dan