Adobe’s “Optimizing Performance for the Flash Platform” recommends that “Use reverse order for while loops” in its “Miscellaneous optimizations” section.

while (--i > -1)

But according to my test significant difference could not be found between decrement and increment. In other language they said that decrement and increment are identical.

The pre-increment/decrement is a little faster than post, which is included in my test, though.