static bool isTrivialLoopExitBlockHelper(Loop *L, BasicBlock *BB,
BasicBlock *&ExitBB,
std::set<BasicBlock*> &Visited) {
- BasicBlock *Header = L->getHeader();
+ if (!Visited.insert(BB).second) {
+ // Already visited and Ok, end of recursion.
+ return true;
+ } else if (!L->contains(BB)) {
+ // Otherwise, this is a loop exit, this is fine so long as this is the
+ // first exit.
+ if (ExitBB != 0) return false;
+ ExitBB = BB;
+ return true;
+ }
+
+ // Otherwise, this is an unvisited intra-loop node. Check all successors.
for (succ_iterator SI = succ_begin(BB), E = succ_end(BB); SI != E; ++SI) {
- if (!Visited.insert(*SI).second) {
- // Already visited and Ok, end of recursion.
- } else if (L->contains(*SI)) {
- // Check to see if the successor is a trivial loop exit.
- if (!isTrivialLoopExitBlockHelper(L, *SI, ExitBB, Visited))
- return false;
- } else {
- // Otherwise, this is a loop exit, this is fine so long as this is the
- // first exit.
- if (ExitBB != 0) return false;
- ExitBB = *SI;
- }
+ // Check to see if the successor is a trivial loop exit.
+ if (!isTrivialLoopExitBlockHelper(L, *SI, ExitBB, Visited))
+ return false;
}
// Okay, everything after this looks good, check to make sure that this block