181e480463d8bb57776d03cebfd083762909023f1Nick Lewycky//===-- CFG.cpp - BasicBlock analysis --------------------------------------==// 281e480463d8bb57776d03cebfd083762909023f1Nick Lewycky// 381e480463d8bb57776d03cebfd083762909023f1Nick Lewycky// The LLVM Compiler Infrastructure 481e480463d8bb57776d03cebfd083762909023f1Nick Lewycky// 581e480463d8bb57776d03cebfd083762909023f1Nick Lewycky// This file is distributed under the University of Illinois Open Source 681e480463d8bb57776d03cebfd083762909023f1Nick Lewycky// License. See LICENSE.TXT for details. 781e480463d8bb57776d03cebfd083762909023f1Nick Lewycky// 881e480463d8bb57776d03cebfd083762909023f1Nick Lewycky//===----------------------------------------------------------------------===// 981e480463d8bb57776d03cebfd083762909023f1Nick Lewycky// 1081e480463d8bb57776d03cebfd083762909023f1Nick Lewycky// This family of functions performs analyses on basic blocks, and instructions 1181e480463d8bb57776d03cebfd083762909023f1Nick Lewycky// contained within basic blocks. 1281e480463d8bb57776d03cebfd083762909023f1Nick Lewycky// 1381e480463d8bb57776d03cebfd083762909023f1Nick Lewycky//===----------------------------------------------------------------------===// 1481e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 1581e480463d8bb57776d03cebfd083762909023f1Nick Lewycky#include "llvm/Analysis/CFG.h" 1681e480463d8bb57776d03cebfd083762909023f1Nick Lewycky#include "llvm/ADT/SmallSet.h" 1781e480463d8bb57776d03cebfd083762909023f1Nick Lewycky#include "llvm/Analysis/LoopInfo.h" 1836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines#include "llvm/IR/Dominators.h" 1981e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 2081e480463d8bb57776d03cebfd083762909023f1Nick Lewyckyusing namespace llvm; 2181e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 2281e480463d8bb57776d03cebfd083762909023f1Nick Lewycky/// FindFunctionBackedges - Analyze the specified function to find all of the 2381e480463d8bb57776d03cebfd083762909023f1Nick Lewycky/// loop backedges in the function and return them. This is a relatively cheap 2481e480463d8bb57776d03cebfd083762909023f1Nick Lewycky/// (compared to computing dominators and loop info) analysis. 2581e480463d8bb57776d03cebfd083762909023f1Nick Lewycky/// 2681e480463d8bb57776d03cebfd083762909023f1Nick Lewycky/// The output is added to Result, as pairs of <from,to> edge info. 2781e480463d8bb57776d03cebfd083762909023f1Nick Lewyckyvoid llvm::FindFunctionBackedges(const Function &F, 2881e480463d8bb57776d03cebfd083762909023f1Nick Lewycky SmallVectorImpl<std::pair<const BasicBlock*,const BasicBlock*> > &Result) { 2981e480463d8bb57776d03cebfd083762909023f1Nick Lewycky const BasicBlock *BB = &F.getEntryBlock(); 3081e480463d8bb57776d03cebfd083762909023f1Nick Lewycky if (succ_begin(BB) == succ_end(BB)) 3181e480463d8bb57776d03cebfd083762909023f1Nick Lewycky return; 3281e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 3381e480463d8bb57776d03cebfd083762909023f1Nick Lewycky SmallPtrSet<const BasicBlock*, 8> Visited; 3481e480463d8bb57776d03cebfd083762909023f1Nick Lewycky SmallVector<std::pair<const BasicBlock*, succ_const_iterator>, 8> VisitStack; 3581e480463d8bb57776d03cebfd083762909023f1Nick Lewycky SmallPtrSet<const BasicBlock*, 8> InStack; 3681e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 3781e480463d8bb57776d03cebfd083762909023f1Nick Lewycky Visited.insert(BB); 3881e480463d8bb57776d03cebfd083762909023f1Nick Lewycky VisitStack.push_back(std::make_pair(BB, succ_begin(BB))); 3981e480463d8bb57776d03cebfd083762909023f1Nick Lewycky InStack.insert(BB); 4081e480463d8bb57776d03cebfd083762909023f1Nick Lewycky do { 4181e480463d8bb57776d03cebfd083762909023f1Nick Lewycky std::pair<const BasicBlock*, succ_const_iterator> &Top = VisitStack.back(); 4281e480463d8bb57776d03cebfd083762909023f1Nick Lewycky const BasicBlock *ParentBB = Top.first; 4381e480463d8bb57776d03cebfd083762909023f1Nick Lewycky succ_const_iterator &I = Top.second; 4481e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 4581e480463d8bb57776d03cebfd083762909023f1Nick Lewycky bool FoundNew = false; 4681e480463d8bb57776d03cebfd083762909023f1Nick Lewycky while (I != succ_end(ParentBB)) { 4781e480463d8bb57776d03cebfd083762909023f1Nick Lewycky BB = *I++; 4881e480463d8bb57776d03cebfd083762909023f1Nick Lewycky if (Visited.insert(BB)) { 4981e480463d8bb57776d03cebfd083762909023f1Nick Lewycky FoundNew = true; 5081e480463d8bb57776d03cebfd083762909023f1Nick Lewycky break; 5181e480463d8bb57776d03cebfd083762909023f1Nick Lewycky } 5281e480463d8bb57776d03cebfd083762909023f1Nick Lewycky // Successor is in VisitStack, it's a back edge. 5381e480463d8bb57776d03cebfd083762909023f1Nick Lewycky if (InStack.count(BB)) 5481e480463d8bb57776d03cebfd083762909023f1Nick Lewycky Result.push_back(std::make_pair(ParentBB, BB)); 5581e480463d8bb57776d03cebfd083762909023f1Nick Lewycky } 5681e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 5781e480463d8bb57776d03cebfd083762909023f1Nick Lewycky if (FoundNew) { 5881e480463d8bb57776d03cebfd083762909023f1Nick Lewycky // Go down one level if there is a unvisited successor. 5981e480463d8bb57776d03cebfd083762909023f1Nick Lewycky InStack.insert(BB); 6081e480463d8bb57776d03cebfd083762909023f1Nick Lewycky VisitStack.push_back(std::make_pair(BB, succ_begin(BB))); 6181e480463d8bb57776d03cebfd083762909023f1Nick Lewycky } else { 6281e480463d8bb57776d03cebfd083762909023f1Nick Lewycky // Go up one level. 6381e480463d8bb57776d03cebfd083762909023f1Nick Lewycky InStack.erase(VisitStack.pop_back_val().first); 6481e480463d8bb57776d03cebfd083762909023f1Nick Lewycky } 6581e480463d8bb57776d03cebfd083762909023f1Nick Lewycky } while (!VisitStack.empty()); 6681e480463d8bb57776d03cebfd083762909023f1Nick Lewycky} 6781e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 6881e480463d8bb57776d03cebfd083762909023f1Nick Lewycky/// GetSuccessorNumber - Search for the specified successor of basic block BB 6981e480463d8bb57776d03cebfd083762909023f1Nick Lewycky/// and return its position in the terminator instruction's list of 7081e480463d8bb57776d03cebfd083762909023f1Nick Lewycky/// successors. It is an error to call this with a block that is not a 7181e480463d8bb57776d03cebfd083762909023f1Nick Lewycky/// successor. 7281e480463d8bb57776d03cebfd083762909023f1Nick Lewyckyunsigned llvm::GetSuccessorNumber(BasicBlock *BB, BasicBlock *Succ) { 7381e480463d8bb57776d03cebfd083762909023f1Nick Lewycky TerminatorInst *Term = BB->getTerminator(); 7481e480463d8bb57776d03cebfd083762909023f1Nick Lewycky#ifndef NDEBUG 7581e480463d8bb57776d03cebfd083762909023f1Nick Lewycky unsigned e = Term->getNumSuccessors(); 7681e480463d8bb57776d03cebfd083762909023f1Nick Lewycky#endif 7781e480463d8bb57776d03cebfd083762909023f1Nick Lewycky for (unsigned i = 0; ; ++i) { 7881e480463d8bb57776d03cebfd083762909023f1Nick Lewycky assert(i != e && "Didn't find edge?"); 7981e480463d8bb57776d03cebfd083762909023f1Nick Lewycky if (Term->getSuccessor(i) == Succ) 8081e480463d8bb57776d03cebfd083762909023f1Nick Lewycky return i; 8181e480463d8bb57776d03cebfd083762909023f1Nick Lewycky } 8281e480463d8bb57776d03cebfd083762909023f1Nick Lewycky} 8381e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 8481e480463d8bb57776d03cebfd083762909023f1Nick Lewycky/// isCriticalEdge - Return true if the specified edge is a critical edge. 8581e480463d8bb57776d03cebfd083762909023f1Nick Lewycky/// Critical edges are edges from a block with multiple successors to a block 8681e480463d8bb57776d03cebfd083762909023f1Nick Lewycky/// with multiple predecessors. 8781e480463d8bb57776d03cebfd083762909023f1Nick Lewyckybool llvm::isCriticalEdge(const TerminatorInst *TI, unsigned SuccNum, 8881e480463d8bb57776d03cebfd083762909023f1Nick Lewycky bool AllowIdenticalEdges) { 8981e480463d8bb57776d03cebfd083762909023f1Nick Lewycky assert(SuccNum < TI->getNumSuccessors() && "Illegal edge specification!"); 9081e480463d8bb57776d03cebfd083762909023f1Nick Lewycky if (TI->getNumSuccessors() == 1) return false; 9181e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 9281e480463d8bb57776d03cebfd083762909023f1Nick Lewycky const BasicBlock *Dest = TI->getSuccessor(SuccNum); 9381e480463d8bb57776d03cebfd083762909023f1Nick Lewycky const_pred_iterator I = pred_begin(Dest), E = pred_end(Dest); 9481e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 9581e480463d8bb57776d03cebfd083762909023f1Nick Lewycky // If there is more than one predecessor, this is a critical edge... 9681e480463d8bb57776d03cebfd083762909023f1Nick Lewycky assert(I != E && "No preds, but we have an edge to the block?"); 9781e480463d8bb57776d03cebfd083762909023f1Nick Lewycky const BasicBlock *FirstPred = *I; 9881e480463d8bb57776d03cebfd083762909023f1Nick Lewycky ++I; // Skip one edge due to the incoming arc from TI. 9981e480463d8bb57776d03cebfd083762909023f1Nick Lewycky if (!AllowIdenticalEdges) 10081e480463d8bb57776d03cebfd083762909023f1Nick Lewycky return I != E; 10181e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 10281e480463d8bb57776d03cebfd083762909023f1Nick Lewycky // If AllowIdenticalEdges is true, then we allow this edge to be considered 10381e480463d8bb57776d03cebfd083762909023f1Nick Lewycky // non-critical iff all preds come from TI's block. 10436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines for (; I != E; ++I) 10536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines if (*I != FirstPred) 10681e480463d8bb57776d03cebfd083762909023f1Nick Lewycky return true; 10781e480463d8bb57776d03cebfd083762909023f1Nick Lewycky return false; 10881e480463d8bb57776d03cebfd083762909023f1Nick Lewycky} 10981e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 11081e480463d8bb57776d03cebfd083762909023f1Nick Lewycky// LoopInfo contains a mapping from basic block to the innermost loop. Find 11181e480463d8bb57776d03cebfd083762909023f1Nick Lewycky// the outermost loop in the loop nest that contains BB. 112328a4fbfbb778de44d9a738c3efdfd42a58925d9Jakub Staszakstatic const Loop *getOutermostLoop(const LoopInfo *LI, const BasicBlock *BB) { 11381e480463d8bb57776d03cebfd083762909023f1Nick Lewycky const Loop *L = LI->getLoopFor(BB); 11481e480463d8bb57776d03cebfd083762909023f1Nick Lewycky if (L) { 11581e480463d8bb57776d03cebfd083762909023f1Nick Lewycky while (const Loop *Parent = L->getParentLoop()) 11681e480463d8bb57776d03cebfd083762909023f1Nick Lewycky L = Parent; 11781e480463d8bb57776d03cebfd083762909023f1Nick Lewycky } 11881e480463d8bb57776d03cebfd083762909023f1Nick Lewycky return L; 11981e480463d8bb57776d03cebfd083762909023f1Nick Lewycky} 12081e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 12181e480463d8bb57776d03cebfd083762909023f1Nick Lewycky// True if there is a loop which contains both BB1 and BB2. 122328a4fbfbb778de44d9a738c3efdfd42a58925d9Jakub Staszakstatic bool loopContainsBoth(const LoopInfo *LI, 12381e480463d8bb57776d03cebfd083762909023f1Nick Lewycky const BasicBlock *BB1, const BasicBlock *BB2) { 12481e480463d8bb57776d03cebfd083762909023f1Nick Lewycky const Loop *L1 = getOutermostLoop(LI, BB1); 12581e480463d8bb57776d03cebfd083762909023f1Nick Lewycky const Loop *L2 = getOutermostLoop(LI, BB2); 126dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines return L1 != nullptr && L1 == L2; 12781e480463d8bb57776d03cebfd083762909023f1Nick Lewycky} 12881e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 12972dba254ae65b06062106910a70d46f21e19d55aNick Lewyckystatic bool isPotentiallyReachableInner(SmallVectorImpl<BasicBlock *> &Worklist, 13072dba254ae65b06062106910a70d46f21e19d55aNick Lewycky BasicBlock *StopBB, 131328a4fbfbb778de44d9a738c3efdfd42a58925d9Jakub Staszak const DominatorTree *DT, 132328a4fbfbb778de44d9a738c3efdfd42a58925d9Jakub Staszak const LoopInfo *LI) { 13381e480463d8bb57776d03cebfd083762909023f1Nick Lewycky // When the stop block is unreachable, it's dominated from everywhere, 13481e480463d8bb57776d03cebfd083762909023f1Nick Lewycky // regardless of whether there's a path between the two blocks. 13581e480463d8bb57776d03cebfd083762909023f1Nick Lewycky if (DT && !DT->isReachableFromEntry(StopBB)) 136dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines DT = nullptr; 13781e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 13881e480463d8bb57776d03cebfd083762909023f1Nick Lewycky // Limit the number of blocks we visit. The goal is to avoid run-away compile 13981e480463d8bb57776d03cebfd083762909023f1Nick Lewycky // times on large CFGs without hampering sensible code. Arbitrarily chosen. 14081e480463d8bb57776d03cebfd083762909023f1Nick Lewycky unsigned Limit = 32; 14181e480463d8bb57776d03cebfd083762909023f1Nick Lewycky SmallSet<const BasicBlock*, 64> Visited; 14281e480463d8bb57776d03cebfd083762909023f1Nick Lewycky do { 14381e480463d8bb57776d03cebfd083762909023f1Nick Lewycky BasicBlock *BB = Worklist.pop_back_val(); 14481e480463d8bb57776d03cebfd083762909023f1Nick Lewycky if (!Visited.insert(BB)) 14581e480463d8bb57776d03cebfd083762909023f1Nick Lewycky continue; 14681e480463d8bb57776d03cebfd083762909023f1Nick Lewycky if (BB == StopBB) 14781e480463d8bb57776d03cebfd083762909023f1Nick Lewycky return true; 14881e480463d8bb57776d03cebfd083762909023f1Nick Lewycky if (DT && DT->dominates(BB, StopBB)) 14981e480463d8bb57776d03cebfd083762909023f1Nick Lewycky return true; 15081e480463d8bb57776d03cebfd083762909023f1Nick Lewycky if (LI && loopContainsBoth(LI, BB, StopBB)) 15181e480463d8bb57776d03cebfd083762909023f1Nick Lewycky return true; 15281e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 15381e480463d8bb57776d03cebfd083762909023f1Nick Lewycky if (!--Limit) { 15481e480463d8bb57776d03cebfd083762909023f1Nick Lewycky // We haven't been able to prove it one way or the other. Conservatively 15581e480463d8bb57776d03cebfd083762909023f1Nick Lewycky // answer true -- that there is potentially a path. 15681e480463d8bb57776d03cebfd083762909023f1Nick Lewycky return true; 15781e480463d8bb57776d03cebfd083762909023f1Nick Lewycky } 15881e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 159dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines if (const Loop *Outer = LI ? getOutermostLoop(LI, BB) : nullptr) { 16081e480463d8bb57776d03cebfd083762909023f1Nick Lewycky // All blocks in a single loop are reachable from all other blocks. From 16181e480463d8bb57776d03cebfd083762909023f1Nick Lewycky // any of these blocks, we can skip directly to the exits of the loop, 16281e480463d8bb57776d03cebfd083762909023f1Nick Lewycky // ignoring any other blocks inside the loop body. 16381e480463d8bb57776d03cebfd083762909023f1Nick Lewycky Outer->getExitBlocks(Worklist); 16481e480463d8bb57776d03cebfd083762909023f1Nick Lewycky } else { 16536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines Worklist.append(succ_begin(BB), succ_end(BB)); 16681e480463d8bb57776d03cebfd083762909023f1Nick Lewycky } 16781e480463d8bb57776d03cebfd083762909023f1Nick Lewycky } while (!Worklist.empty()); 16881e480463d8bb57776d03cebfd083762909023f1Nick Lewycky 16972dba254ae65b06062106910a70d46f21e19d55aNick Lewycky // We have exhausted all possible paths and are certain that 'To' can not be 17072dba254ae65b06062106910a70d46f21e19d55aNick Lewycky // reached from 'From'. 17181e480463d8bb57776d03cebfd083762909023f1Nick Lewycky return false; 17281e480463d8bb57776d03cebfd083762909023f1Nick Lewycky} 17372dba254ae65b06062106910a70d46f21e19d55aNick Lewycky 17472dba254ae65b06062106910a70d46f21e19d55aNick Lewyckybool llvm::isPotentiallyReachable(const BasicBlock *A, const BasicBlock *B, 175328a4fbfbb778de44d9a738c3efdfd42a58925d9Jakub Staszak const DominatorTree *DT, const LoopInfo *LI) { 17672dba254ae65b06062106910a70d46f21e19d55aNick Lewycky assert(A->getParent() == B->getParent() && 17772dba254ae65b06062106910a70d46f21e19d55aNick Lewycky "This analysis is function-local!"); 17872dba254ae65b06062106910a70d46f21e19d55aNick Lewycky 17972dba254ae65b06062106910a70d46f21e19d55aNick Lewycky SmallVector<BasicBlock*, 32> Worklist; 18072dba254ae65b06062106910a70d46f21e19d55aNick Lewycky Worklist.push_back(const_cast<BasicBlock*>(A)); 18172dba254ae65b06062106910a70d46f21e19d55aNick Lewycky 18272dba254ae65b06062106910a70d46f21e19d55aNick Lewycky return isPotentiallyReachableInner(Worklist, const_cast<BasicBlock*>(B), 18372dba254ae65b06062106910a70d46f21e19d55aNick Lewycky DT, LI); 18472dba254ae65b06062106910a70d46f21e19d55aNick Lewycky} 18572dba254ae65b06062106910a70d46f21e19d55aNick Lewycky 18672dba254ae65b06062106910a70d46f21e19d55aNick Lewyckybool llvm::isPotentiallyReachable(const Instruction *A, const Instruction *B, 187328a4fbfbb778de44d9a738c3efdfd42a58925d9Jakub Staszak const DominatorTree *DT, const LoopInfo *LI) { 18872dba254ae65b06062106910a70d46f21e19d55aNick Lewycky assert(A->getParent()->getParent() == B->getParent()->getParent() && 18972dba254ae65b06062106910a70d46f21e19d55aNick Lewycky "This analysis is function-local!"); 19072dba254ae65b06062106910a70d46f21e19d55aNick Lewycky 19172dba254ae65b06062106910a70d46f21e19d55aNick Lewycky SmallVector<BasicBlock*, 32> Worklist; 19272dba254ae65b06062106910a70d46f21e19d55aNick Lewycky 19372dba254ae65b06062106910a70d46f21e19d55aNick Lewycky if (A->getParent() == B->getParent()) { 19472dba254ae65b06062106910a70d46f21e19d55aNick Lewycky // The same block case is special because it's the only time we're looking 19572dba254ae65b06062106910a70d46f21e19d55aNick Lewycky // within a single block to see which instruction comes first. Once we 19672dba254ae65b06062106910a70d46f21e19d55aNick Lewycky // start looking at multiple blocks, the first instruction of the block is 19772dba254ae65b06062106910a70d46f21e19d55aNick Lewycky // reachable, so we only need to determine reachability between whole 19872dba254ae65b06062106910a70d46f21e19d55aNick Lewycky // blocks. 19972dba254ae65b06062106910a70d46f21e19d55aNick Lewycky BasicBlock *BB = const_cast<BasicBlock *>(A->getParent()); 20072dba254ae65b06062106910a70d46f21e19d55aNick Lewycky 20172dba254ae65b06062106910a70d46f21e19d55aNick Lewycky // If the block is in a loop then we can reach any instruction in the block 20272dba254ae65b06062106910a70d46f21e19d55aNick Lewycky // from any other instruction in the block by going around a backedge. 203dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines if (LI && LI->getLoopFor(BB) != nullptr) 20472dba254ae65b06062106910a70d46f21e19d55aNick Lewycky return true; 20572dba254ae65b06062106910a70d46f21e19d55aNick Lewycky 20672dba254ae65b06062106910a70d46f21e19d55aNick Lewycky // Linear scan, start at 'A', see whether we hit 'B' or the end first. 20772dba254ae65b06062106910a70d46f21e19d55aNick Lewycky for (BasicBlock::const_iterator I = A, E = BB->end(); I != E; ++I) { 20872dba254ae65b06062106910a70d46f21e19d55aNick Lewycky if (&*I == B) 20972dba254ae65b06062106910a70d46f21e19d55aNick Lewycky return true; 21072dba254ae65b06062106910a70d46f21e19d55aNick Lewycky } 21172dba254ae65b06062106910a70d46f21e19d55aNick Lewycky 21272dba254ae65b06062106910a70d46f21e19d55aNick Lewycky // Can't be in a loop if it's the entry block -- the entry block may not 21372dba254ae65b06062106910a70d46f21e19d55aNick Lewycky // have predecessors. 21472dba254ae65b06062106910a70d46f21e19d55aNick Lewycky if (BB == &BB->getParent()->getEntryBlock()) 21572dba254ae65b06062106910a70d46f21e19d55aNick Lewycky return false; 21672dba254ae65b06062106910a70d46f21e19d55aNick Lewycky 21772dba254ae65b06062106910a70d46f21e19d55aNick Lewycky // Otherwise, continue doing the normal per-BB CFG walk. 21836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines Worklist.append(succ_begin(BB), succ_end(BB)); 21972dba254ae65b06062106910a70d46f21e19d55aNick Lewycky 22072dba254ae65b06062106910a70d46f21e19d55aNick Lewycky if (Worklist.empty()) { 22172dba254ae65b06062106910a70d46f21e19d55aNick Lewycky // We've proven that there's no path! 22272dba254ae65b06062106910a70d46f21e19d55aNick Lewycky return false; 22372dba254ae65b06062106910a70d46f21e19d55aNick Lewycky } 22472dba254ae65b06062106910a70d46f21e19d55aNick Lewycky } else { 22572dba254ae65b06062106910a70d46f21e19d55aNick Lewycky Worklist.push_back(const_cast<BasicBlock*>(A->getParent())); 22672dba254ae65b06062106910a70d46f21e19d55aNick Lewycky } 22772dba254ae65b06062106910a70d46f21e19d55aNick Lewycky 22872dba254ae65b06062106910a70d46f21e19d55aNick Lewycky if (A->getParent() == &A->getParent()->getParent()->getEntryBlock()) 22972dba254ae65b06062106910a70d46f21e19d55aNick Lewycky return true; 23072dba254ae65b06062106910a70d46f21e19d55aNick Lewycky if (B->getParent() == &A->getParent()->getParent()->getEntryBlock()) 23172dba254ae65b06062106910a70d46f21e19d55aNick Lewycky return false; 23272dba254ae65b06062106910a70d46f21e19d55aNick Lewycky 23372dba254ae65b06062106910a70d46f21e19d55aNick Lewycky return isPotentiallyReachableInner(Worklist, 23472dba254ae65b06062106910a70d46f21e19d55aNick Lewycky const_cast<BasicBlock*>(B->getParent()), 23572dba254ae65b06062106910a70d46f21e19d55aNick Lewycky DT, LI); 23672dba254ae65b06062106910a70d46f21e19d55aNick Lewycky} 237