9 // An irreducible SCC is one which has multiple "header" blocks, i.e., blocks
22 // INPUT CFG: The blocks A and B form an irreducible loop with two headers.
55 // takes a set of incoming blocks (the predecessors) and outgoing blocks (the
57 // hub. Since the hub dominates all the outgoing blocks, each such PHINode
116                                 SetVector<BasicBlock *> &Blocks,  in INITIALIZE_PASS_DEPENDENCY()
125         return L == NewLoop || !Blocks.contains(L->getHeader());  in INITIALIZE_PASS_DEPENDENCY()
137       for (auto *BB : Child->blocks()) {  in INITIALIZE_PASS_DEPENDENCY()
161 // Given a set of blocks and headers in an irreducible SCC, convert it into a
166                                       SetVector<BasicBlock *> &Blocks,  in createNaturalLoopInternal()  argument
171     assert(Blocks.count(H));  in createNaturalLoopInternal()
190   // of guard blocks that manage the flow of control from the  in createNaturalLoopInternal()
209   // Add the guard blocks to the new loop. The first guard block is  in createNaturalLoopInternal()
212   // header. Since the new loop is already in LoopInfo, the new blocks  in createNaturalLoopInternal()
219   // Add the SCC blocks to the new loop.  in createNaturalLoopInternal()
220   for (auto *BB : Blocks) {  in createNaturalLoopInternal()
233   reconnectChildLoops(LI, ParentLoop, NewLoop, Blocks, Headers);  in createNaturalLoopInternal()
254                               SetVector<BasicBlock *> &Blocks,  in createNaturalLoop()  argument
256   createNaturalLoopInternal(LI, DT, nullptr, Blocks, Headers);  in createNaturalLoop()
260                               SetVector<BasicBlock *> &Blocks,  in createNaturalLoop()  argument
262   createNaturalLoopInternal(LI, DT, &L, Blocks, Headers);  in createNaturalLoop()
272     SetVector<BasicBlock *> Blocks;  in makeReducible()  local
277       Blocks.insert(BB);  in makeReducible()
281     // Minor optimization: The SCC blocks are usually discovered in an order  in makeReducible()
282     // that is the opposite of the order in which these blocks appear as branch  in makeReducible()
288     for (auto *BB : reverse(Blocks)) {  in makeReducible()
293         if (!Blocks.count(P)) {  in makeReducible()
307     createNaturalLoop(LI, DT, G, Blocks, Headers);  in makeReducible()