+ // Populate the loop queue in reverse program order. There is no clear need to
+ // process sibling loops in either forward or reverse order. There may be some
+ // advantage in deleting uses in a later loop before optimizing the
+ // definitions in an earlier loop. If we find a clear reason to process in
+ // forward order, then a forward variant of LoopPassManager should be created.
+ //
+ // Note that LoopInfo::iterator visits loops in reverse program
+ // order. Here, reverse_iterator gives us a forward order, and the LoopQueue
+ // reverses the order a third time by popping from the back.
+ for (LoopInfo::reverse_iterator I = LI->rbegin(), E = LI->rend(); I != E; ++I)