C++ SmallPtrSet::end方法代码示例

// Calculate Edge Weights using "Loop Branch Heuristics". Predict backedges
// as taken, exiting edges as not-taken.
bool BranchProbabilityInfo::calcLoopBranchHeuristics(BasicBlock *BB) {
  Loop *L = LI->getLoopFor(BB);
  if (!L)
    return false;

  SmallPtrSet<BasicBlock *, 8> BackEdges;
  SmallPtrSet<BasicBlock *, 8> ExitingEdges;
  SmallPtrSet<BasicBlock *, 8> InEdges; // Edges from header to the loop.

  for (succ_iterator I = succ_begin(BB), E = succ_end(BB); I != E; ++I) {
    if (!L->contains(*I))
      ExitingEdges.insert(*I);
    else if (L->getHeader() == *I)
      BackEdges.insert(*I);
    else
      InEdges.insert(*I);
  }

  if (uint32_t numBackEdges = BackEdges.size()) {
    uint32_t backWeight = LBH_TAKEN_WEIGHT / numBackEdges;
    if (backWeight < NORMAL_WEIGHT)
      backWeight = NORMAL_WEIGHT;

    for (SmallPtrSet<BasicBlock *, 8>::iterator EI = BackEdges.begin(),
         EE = BackEdges.end(); EI != EE; ++EI) {
      BasicBlock *Back = *EI;
      setEdgeWeight(BB, Back, backWeight);
    }
  }

  if (uint32_t numInEdges = InEdges.size()) {
    uint32_t inWeight = LBH_TAKEN_WEIGHT / numInEdges;
    if (inWeight < NORMAL_WEIGHT)
      inWeight = NORMAL_WEIGHT;

    for (SmallPtrSet<BasicBlock *, 8>::iterator EI = InEdges.begin(),
         EE = InEdges.end(); EI != EE; ++EI) {
      BasicBlock *Back = *EI;
      setEdgeWeight(BB, Back, inWeight);
    }
  }

  if (uint32_t numExitingEdges = ExitingEdges.size()) {
    uint32_t exitWeight = LBH_NONTAKEN_WEIGHT / numExitingEdges;
    if (exitWeight < MIN_WEIGHT)
      exitWeight = MIN_WEIGHT;

    for (SmallPtrSet<BasicBlock *, 8>::iterator EI = ExitingEdges.begin(),
         EE = ExitingEdges.end(); EI != EE; ++EI) {
      BasicBlock *Exiting = *EI;
      setEdgeWeight(BB, Exiting, exitWeight);
    }
  }

  return true;
}

TEST(SmallPtrSetTest, GrowthTest) {
  int i;
  int buf[8];
  for(i=0; i<8; ++i) buf[i]=0;


  SmallPtrSet<int *, 4> s;
  typedef SmallPtrSet<int *, 4>::iterator iter;
  
  s.insert(&buf[0]);
  s.insert(&buf[1]);
  s.insert(&buf[2]);
  s.insert(&buf[3]);
  EXPECT_EQ(4U, s.size());

  i = 0;
  for(iter I=s.begin(), E=s.end(); I!=E; ++I, ++i)
      (**I)++;
  EXPECT_EQ(4, i);
  for(i=0; i<8; ++i)
      EXPECT_EQ(i<4?1:0,buf[i]);

  s.insert(&buf[4]);
  s.insert(&buf[5]);
  s.insert(&buf[6]);
  s.insert(&buf[7]);

  i = 0;
  for(iter I=s.begin(), E=s.end(); I!=E; ++I, ++i)
      (**I)++;
  EXPECT_EQ(8, i);
  s.erase(&buf[4]);
  s.erase(&buf[5]);
  s.erase(&buf[6]);
  s.erase(&buf[7]);
  EXPECT_EQ(4U, s.size());

  i = 0;
  for(iter I=s.begin(), E=s.end(); I!=E; ++I, ++i)
      (**I)++;
  EXPECT_EQ(4, i);
  for(i=0; i<8; ++i)
      EXPECT_EQ(i<4?3:1,buf[i]);

  s.clear();
  for(i=0; i<8; ++i) buf[i]=0;
  for(i=0; i<128; ++i) s.insert(&buf[i%8]); // test repeated entires
  EXPECT_EQ(8U, s.size());
  for(iter I=s.begin(), E=s.end(); I!=E; ++I, ++i)
      (**I)++;
  for(i=0; i<8; ++i)
      EXPECT_EQ(1,buf[i]);
}

void LTOCodeGenerator::applyScopeRestrictions() {
  if (ScopeRestrictionsDone)
    return;
  Module *mergedModule = Linker.getModule();

  // Start off with a verification pass.
  PassManager passes;
  passes.add(createVerifierPass());

  // mark which symbols can not be internalized
  Mangler Mangler(TargetMach);
  std::vector<const char*> MustPreserveList;
  SmallPtrSet<GlobalValue*, 8> AsmUsed;
  std::vector<StringRef> Libcalls;
  TargetLibraryInfo TLI(Triple(TargetMach->getTargetTriple()));
  accumulateAndSortLibcalls(Libcalls, TLI, TargetMach->getTargetLowering());

  for (Module::iterator f = mergedModule->begin(),
         e = mergedModule->end(); f != e; ++f)
    applyRestriction(*f, Libcalls, MustPreserveList, AsmUsed, Mangler);
  for (Module::global_iterator v = mergedModule->global_begin(),
         e = mergedModule->global_end(); v !=  e; ++v)
    applyRestriction(*v, Libcalls, MustPreserveList, AsmUsed, Mangler);
  for (Module::alias_iterator a = mergedModule->alias_begin(),
         e = mergedModule->alias_end(); a != e; ++a)
    applyRestriction(*a, Libcalls, MustPreserveList, AsmUsed, Mangler);

  GlobalVariable *LLVMCompilerUsed =
    mergedModule->getGlobalVariable("llvm.compiler.used");
  findUsedValues(LLVMCompilerUsed, AsmUsed);
  if (LLVMCompilerUsed)
    LLVMCompilerUsed->eraseFromParent();

  if (!AsmUsed.empty()) {
    llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(Context);
    std::vector<Constant*> asmUsed2;
    for (SmallPtrSet<GlobalValue*, 16>::const_iterator i = AsmUsed.begin(),
           e = AsmUsed.end(); i !=e; ++i) {
      GlobalValue *GV = *i;
      Constant *c = ConstantExpr::getBitCast(GV, i8PTy);
      asmUsed2.push_back(c);
    }

    llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, asmUsed2.size());
    LLVMCompilerUsed =
      new llvm::GlobalVariable(*mergedModule, ATy, false,
                               llvm::GlobalValue::AppendingLinkage,
                               llvm::ConstantArray::get(ATy, asmUsed2),
                               "llvm.compiler.used");

    LLVMCompilerUsed->setSection("llvm.metadata");
  }

  passes.add(createInternalizePass(MustPreserveList));

  // apply scope restrictions
  passes.run(*mergedModule);

  ScopeRestrictionsDone = true;
}

/// forwardResume - Forward the 'resume' instruction to the caller's landing pad
/// block. When the landing pad block has only one predecessor, this is a simple
/// branch. When there is more than one predecessor, we need to split the
/// landing pad block after the landingpad instruction and jump to there.
void InvokeInliningInfo::forwardResume(ResumeInst *RI,
                               SmallPtrSet<LandingPadInst*, 16> &InlinedLPads) {
  BasicBlock *Dest = getInnerResumeDest();
  LandingPadInst *OuterLPad = getLandingPadInst();
  BasicBlock *Src = RI->getParent();

  BranchInst::Create(Dest, Src);

  // Update the PHIs in the destination. They were inserted in an order which
  // makes this work.
  addIncomingPHIValuesForInto(Src, Dest);

  InnerEHValuesPHI->addIncoming(RI->getOperand(0), Src);
  RI->eraseFromParent();

  // Append the clauses from the outer landing pad instruction into the inlined
  // landing pad instructions.
  for (SmallPtrSet<LandingPadInst*, 16>::iterator I = InlinedLPads.begin(),
         E = InlinedLPads.end(); I != E; ++I) {
    LandingPadInst *InlinedLPad = *I;
    for (unsigned OuterIdx = 0, OuterNum = OuterLPad->getNumClauses();
         OuterIdx != OuterNum; ++OuterIdx)
      InlinedLPad->addClause(OuterLPad->getClause(OuterIdx));
  }
}

/// ProcessLoop - Walk the loop structure in depth first order, ensuring that
/// all loops have preheaders.
///
bool LoopSimplify::ProcessLoop(Loop *L, LPPassManager &LPM) {
  bool Changed = false;
ReprocessLoop:

  // Check to see that no blocks (other than the header) in this loop have
  // predecessors that are not in the loop.  This is not valid for natural
  // loops, but can occur if the blocks are unreachable.  Since they are
  // unreachable we can just shamelessly delete those CFG edges!
  for (Loop::block_iterator BB = L->block_begin(), E = L->block_end();
       BB != E; ++BB) {
    if (*BB == L->getHeader()) continue;

    SmallPtrSet<BasicBlock*, 4> BadPreds;
    for (pred_iterator PI = pred_begin(*BB),
         PE = pred_end(*BB); PI != PE; ++PI) {
      BasicBlock *P = *PI;
      if (!L->contains(P))
        BadPreds.insert(P);
    }

    // Delete each unique out-of-loop (and thus dead) predecessor.
    for (SmallPtrSet<BasicBlock*, 4>::iterator I = BadPreds.begin(),
         E = BadPreds.end(); I != E; ++I) {

      DEBUG(dbgs() << "LoopSimplify: Deleting edge from dead predecessor ";
            WriteAsOperand(dbgs(), *I, false);
            dbgs() << "\n");

      // Inform each successor of each dead pred.
      for (succ_iterator SI = succ_begin(*I), SE = succ_end(*I); SI != SE; ++SI)
        (*SI)->removePredecessor(*I);
      // Zap the dead pred's terminator and replace it with unreachable.
      TerminatorInst *TI = (*I)->getTerminator();
       TI->replaceAllUsesWith(UndefValue::get(TI->getType()));
      (*I)->getTerminator()->eraseFromParent();
      new UnreachableInst((*I)->getContext(), *I);
      Changed = true;
    }
  }

  // If there are exiting blocks with branches on undef, resolve the undef in
  // the direction which will exit the loop. This will help simplify loop
  // trip count computations.
  SmallVector<BasicBlock*, 8> ExitingBlocks;
  L->getExitingBlocks(ExitingBlocks);
  for (SmallVectorImpl<BasicBlock *>::iterator I = ExitingBlocks.begin(),
       E = ExitingBlocks.end(); I != E; ++I)
    if (BranchInst *BI = dyn_cast<BranchInst>((*I)->getTerminator()))
      if (BI->isConditional()) {
        if (UndefValue *Cond = dyn_cast<UndefValue>(BI->getCondition())) {

          DEBUG(dbgs() << "LoopSimplify: Resolving \"br i1 undef\" to exit in ";
                WriteAsOperand(dbgs(), *I, false);
                dbgs() << "\n");

          BI->setCondition(ConstantInt::get(Cond->getType(),
                                            !L->contains(BI->getSuccessor(0))));
          Changed = true;
        }
      }

/// RemoveAccessedObjects - Check to see if the specified location may alias any
/// of the stack objects in the DeadStackObjects set.  If so, they become live
/// because the location is being loaded.
void DSE::RemoveAccessedObjects(const AliasAnalysis::Location &LoadedLoc,
                                SmallPtrSet<Value*, 16> &DeadStackObjects) {
  const Value *UnderlyingPointer = LoadedLoc.Ptr->getUnderlyingObject();

  // A constant can't be in the dead pointer set.
  if (isa<Constant>(UnderlyingPointer))
    return;
  
  // If the kill pointer can be easily reduced to an alloca, don't bother doing
  // extraneous AA queries.
  if (isa<AllocaInst>(UnderlyingPointer) || isa<Argument>(UnderlyingPointer)) {
    DeadStackObjects.erase(const_cast<Value*>(UnderlyingPointer));
    return;
  }
  
  SmallVector<Value*, 16> NowLive;
  for (SmallPtrSet<Value*, 16>::iterator I = DeadStackObjects.begin(),
       E = DeadStackObjects.end(); I != E; ++I) {
    // See if the loaded location could alias the stack location.
    AliasAnalysis::Location StackLoc(*I, getPointerSize(*I, *AA));
    if (!AA->isNoAlias(StackLoc, LoadedLoc))
      NowLive.push_back(*I);
  }

  for (SmallVector<Value*, 16>::iterator I = NowLive.begin(), E = NowLive.end();
       I != E; ++I)
    DeadStackObjects.erase(*I);
}

void LTOCodeGenerator::applyScopeRestrictions() {
  if (_scopeRestrictionsDone) return;
  Module *mergedModule = _linker.getModule();

  // Start off with a verification pass.
  PassManager passes;
  passes.add(createVerifierPass());

  // mark which symbols can not be internalized
  MCContext Context(*_target->getMCAsmInfo(), *_target->getRegisterInfo(),NULL);
  Mangler mangler(Context, *_target->getTargetData());
  std::vector<const char*> mustPreserveList;
  SmallPtrSet<GlobalValue*, 8> asmUsed;

  for (Module::iterator f = mergedModule->begin(),
         e = mergedModule->end(); f != e; ++f)
    applyRestriction(*f, mustPreserveList, asmUsed, mangler);
  for (Module::global_iterator v = mergedModule->global_begin(),
         e = mergedModule->global_end(); v !=  e; ++v)
    applyRestriction(*v, mustPreserveList, asmUsed, mangler);
  for (Module::alias_iterator a = mergedModule->alias_begin(),
         e = mergedModule->alias_end(); a != e; ++a)
    applyRestriction(*a, mustPreserveList, asmUsed, mangler);

  GlobalVariable *LLVMCompilerUsed =
    mergedModule->getGlobalVariable("llvm.compiler.used");
  findUsedValues(LLVMCompilerUsed, asmUsed);
  if (LLVMCompilerUsed)
    LLVMCompilerUsed->eraseFromParent();

  llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(_context);
  std::vector<Constant*> asmUsed2;
  for (SmallPtrSet<GlobalValue*, 16>::const_iterator i = asmUsed.begin(),
         e = asmUsed.end(); i !=e; ++i) {
    GlobalValue *GV = *i;
    Constant *c = ConstantExpr::getBitCast(GV, i8PTy);
    asmUsed2.push_back(c);
  }

  llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, asmUsed2.size());
  LLVMCompilerUsed =
    new llvm::GlobalVariable(*mergedModule, ATy, false,
                             llvm::GlobalValue::AppendingLinkage,
                             llvm::ConstantArray::get(ATy, asmUsed2),
                             "llvm.compiler.used");

  LLVMCompilerUsed->setSection("llvm.metadata");

  // Add prerequisite passes needed by SAFECode
  PassManagerBuilder().populateLTOPassManager(passes, /*Internalize=*/ false,
                                              !DisableInline);

  passes.add(createInternalizePass(mustPreserveList));

  // apply scope restrictions
  passes.run(*mergedModule);

  _scopeRestrictionsDone = true;
}

/// \brief Calculate edge weights for successors lead to unreachable.
///
/// Predict that a successor which leads necessarily to an
/// unreachable-terminated block as extremely unlikely.
bool BranchProbabilityInfo::calcUnreachableHeuristics(BasicBlock *BB) {
  TerminatorInst *TI = BB->getTerminator();
  if (TI->getNumSuccessors() == 0) {
    if (isa<UnreachableInst>(TI))
      PostDominatedByUnreachable.insert(BB);
    return false;
  }

  SmallPtrSet<BasicBlock *, 4> UnreachableEdges;
  SmallPtrSet<BasicBlock *, 4> ReachableEdges;

  for (succ_iterator I = succ_begin(BB), E = succ_end(BB); I != E; ++I) {
    if (PostDominatedByUnreachable.count(*I))
      UnreachableEdges.insert(*I);
    else
      ReachableEdges.insert(*I);
  }

  // If all successors are in the set of blocks post-dominated by unreachable,
  // this block is too.
  if (UnreachableEdges.size() == TI->getNumSuccessors())
    PostDominatedByUnreachable.insert(BB);

  // Skip probabilities if this block has a single successor or if all were
  // reachable.
  if (TI->getNumSuccessors() == 1 || UnreachableEdges.empty())
    return false;

  uint32_t UnreachableWeight =
    std::max(UR_TAKEN_WEIGHT / UnreachableEdges.size(), MIN_WEIGHT);
  for (SmallPtrSet<BasicBlock *, 4>::iterator I = UnreachableEdges.begin(),
                                              E = UnreachableEdges.end();
       I != E; ++I)
    setEdgeWeight(BB, *I, UnreachableWeight);

  if (ReachableEdges.empty())
    return true;
  uint32_t ReachableWeight =
    std::max(UR_NONTAKEN_WEIGHT / ReachableEdges.size(), NORMAL_WEIGHT);
  for (SmallPtrSet<BasicBlock *, 4>::iterator I = ReachableEdges.begin(),
                                              E = ReachableEdges.end();
       I != E; ++I)
    setEdgeWeight(BB, *I, ReachableWeight);

  return true;
}

/// removeDeadFunctions - Remove dead functions that are not included in
/// DNR (Do Not Remove) list.
bool Inliner::removeDeadFunctions(CallGraph &CG, 
                                  SmallPtrSet<const Function *, 16> *DNR) {
  SmallPtrSet<CallGraphNode*, 16> FunctionsToRemove;

  // Scan for all of the functions, looking for ones that should now be removed
  // from the program.  Insert the dead ones in the FunctionsToRemove set.
  for (CallGraph::iterator I = CG.begin(), E = CG.end(); I != E; ++I) {
    CallGraphNode *CGN = I->second;
    if (CGN->getFunction() == 0)
      continue;
    
    Function *F = CGN->getFunction();
    
    // If the only remaining users of the function are dead constants, remove
    // them.
    F->removeDeadConstantUsers();

    if (DNR && DNR->count(F))
      continue;
    if (!F->hasLinkOnceLinkage() && !F->hasLocalLinkage() &&
        !F->hasAvailableExternallyLinkage())
      continue;
    if (!F->use_empty())
      continue;
    
    // Remove any call graph edges from the function to its callees.
    CGN->removeAllCalledFunctions();

    // Remove any edges from the external node to the function's call graph
    // node.  These edges might have been made irrelegant due to
    // optimization of the program.
    CG.getExternalCallingNode()->removeAnyCallEdgeTo(CGN);

    // Removing the node for callee from the call graph and delete it.
    FunctionsToRemove.insert(CGN);
  }

  // Now that we know which functions to delete, do so.  We didn't want to do
  // this inline, because that would invalidate our CallGraph::iterator
  // objects. :(
  //
  // Note that it doesn't matter that we are iterating over a non-stable set
  // here to do this, it doesn't matter which order the functions are deleted
  // in.
  bool Changed = false;
  for (SmallPtrSet<CallGraphNode*, 16>::iterator I = FunctionsToRemove.begin(),
       E = FunctionsToRemove.end(); I != E; ++I) {
    resetCachedCostInfo((*I)->getFunction());
    delete CG.removeFunctionFromModule(*I);
    ++NumDeleted;
    Changed = true;
  }

  return Changed;
}

/// Test if there is any edge from V in the upper direction
bool ABCD::InequalityGraph::hasEdge(Value *V, bool upper) const {
  SmallPtrSet<Edge *, 16> it = graph.lookup(V);

  SmallPtrSet<Edge *, 16>::iterator begin = it.begin();
  SmallPtrSet<Edge *, 16>::iterator end = it.end();
  for (; begin != end; ++begin) {
    if ((*begin)->isUpperBound() == upper) {
      return true;
    }
  }
  return false;
}

void LowerEmAsyncify::FindContextVariables(AsyncCallEntry & Entry) {
  BasicBlock *AfterCallBlock = Entry.AfterCallBlock;

  Function & F = *AfterCallBlock->getParent();

  // Create a new entry block as if in the callback function
  // theck check variables that no longer properly dominate their uses
  BasicBlock *EntryBlock = BasicBlock::Create(TheModule->getContext(), "", &F, &F.getEntryBlock());
  BranchInst::Create(AfterCallBlock, EntryBlock);

  DominatorTreeWrapperPass DTW;
  DTW.runOnFunction(F);
  DominatorTree& DT = DTW.getDomTree();

  // These blocks may be using some values defined at or before AsyncCallBlock
  BasicBlockSet Ramifications = FindReachableBlocksFrom(AfterCallBlock); 

  SmallPtrSet<Value*, 256> ContextVariables;
  Values Pending;

  // Examine the instructions, find all variables that we need to store in the context
  for (BasicBlockSet::iterator RI = Ramifications.begin(), RE = Ramifications.end(); RI != RE; ++RI) {
    for (BasicBlock::iterator I = (*RI)->begin(), E = (*RI)->end(); I != E; ++I) {
      for (unsigned i = 0, NumOperands = I->getNumOperands(); i < NumOperands; ++i) {
        Value *O = I->getOperand(i);
        if (Instruction *Inst = dyn_cast<Instruction>(O)) {
          if (Inst == Entry.AsyncCallInst) continue; // for the original async call, we will load directly from async return value
          if (ContextVariables.count(Inst) != 0)  continue; // already examined 

          if (!DT.dominates(Inst, I->getOperandUse(i))) {
            // `I` is using `Inst`, yet `Inst` does not dominate `I` if we arrive directly at AfterCallBlock
            // so we need to save `Inst` in the context
            ContextVariables.insert(Inst);
            Pending.push_back(Inst);
          }
        } else if (Argument *Arg = dyn_cast<Argument>(O)) {
          // count() should be as fast/slow as insert, so just insert here 
          ContextVariables.insert(Arg);
        }
      }
    }
  }

  // restore F
  EntryBlock->eraseFromParent();  

  Entry.ContextVariables.clear();
  Entry.ContextVariables.reserve(ContextVariables.size());
  for (SmallPtrSet<Value*, 256>::iterator I = ContextVariables.begin(), E = ContextVariables.end(); I != E; ++I) {
    Entry.ContextVariables.push_back(*I);
  }
}

bool ReduceCrashingInstructions::TestInsts(std::vector<const Instruction*>
                                           &Insts) {
  // Clone the program to try hacking it apart...
  ValueToValueMapTy VMap;
  Module *M = CloneModule(BD.getProgram(), VMap);

  // Convert list to set for fast lookup...
  SmallPtrSet<Instruction*, 64> Instructions;
  for (unsigned i = 0, e = Insts.size(); i != e; ++i) {
    assert(!isa<TerminatorInst>(Insts[i]));
    Instructions.insert(cast<Instruction>(VMap[Insts[i]]));
  }

  outs() << "Checking for crash with only " << Instructions.size();
  if (Instructions.size() == 1)
    outs() << " instruction: ";
  else
    outs() << " instructions: ";

  for (Module::iterator MI = M->begin(), ME = M->end(); MI != ME; ++MI)
    for (Function::iterator FI = MI->begin(), FE = MI->end(); FI != FE; ++FI)
      for (BasicBlock::iterator I = FI->begin(), E = FI->end(); I != E;) {
        Instruction *Inst = I++;
        if (!Instructions.count(Inst) && !isa<TerminatorInst>(Inst) &&
            !isa<LandingPadInst>(Inst)) {
          if (!Inst->getType()->isVoidTy())
            Inst->replaceAllUsesWith(UndefValue::get(Inst->getType()));
          Inst->eraseFromParent();
        }
      }

  // Verify that this is still valid.
  PassManager Passes;
  Passes.add(createVerifierPass());
  Passes.add(createDebugInfoVerifierPass());
  Passes.run(*M);

  // Try running on the hacked up program...
  if (TestFn(BD, M)) {
    BD.setNewProgram(M);      // It crashed, keep the trimmed version...

    // Make sure to use instruction pointers that point into the now-current
    // module, and that they don't include any deleted blocks.
    Insts.clear();
    for (SmallPtrSet<Instruction*, 64>::const_iterator I = Instructions.begin(),
             E = Instructions.end(); I != E; ++I)
      Insts.push_back(*I);
    return true;
  }
  delete M;  // It didn't crash, try something else.
  return false;
}

// Calculate Edge Weights using "Return Heuristics". Predict a successor which
// leads directly to Return Instruction will not be taken.
bool BranchProbabilityAnalysis::calcReturnHeuristics(BasicBlock *BB){
  if (BB->getTerminator()->getNumSuccessors() == 1)
    return false;

  SmallPtrSet<BasicBlock *, 4> ReturningEdges;
  SmallPtrSet<BasicBlock *, 4> StayEdges;

  for (succ_iterator I = succ_begin(BB), E = succ_end(BB); I != E; ++I) {
    BasicBlock *Succ = *I;
    if (isReturningBlock(Succ))
      ReturningEdges.insert(Succ);
    else
      StayEdges.insert(Succ);
  }

  if (uint32_t numStayEdges = StayEdges.size()) {
    uint32_t stayWeight = RH_TAKEN_WEIGHT / numStayEdges;
    if (stayWeight < NORMAL_WEIGHT)
      stayWeight = NORMAL_WEIGHT;

    for (SmallPtrSet<BasicBlock *, 4>::iterator I = StayEdges.begin(),
         E = StayEdges.end(); I != E; ++I)
      BP->setEdgeWeight(BB, *I, stayWeight);
  }

  if (uint32_t numRetEdges = ReturningEdges.size()) {
    uint32_t retWeight = RH_NONTAKEN_WEIGHT / numRetEdges;
    if (retWeight < MIN_WEIGHT)
      retWeight = MIN_WEIGHT;
    for (SmallPtrSet<BasicBlock *, 4>::iterator I = ReturningEdges.begin(),
         E = ReturningEdges.end(); I != E; ++I) {
      BP->setEdgeWeight(BB, *I, retWeight);
    }
  }

  return ReturningEdges.size() > 0;
}

/// HandleInlinedInvoke - If we inlined an invoke site, we need to convert calls
/// in the body of the inlined function into invokes.
///
/// II is the invoke instruction being inlined.  FirstNewBlock is the first
/// block of the inlined code (the last block is the end of the function),
/// and InlineCodeInfo is information about the code that got inlined.
static void HandleInlinedInvoke(InvokeInst *II, BasicBlock *FirstNewBlock,
                                ClonedCodeInfo &InlinedCodeInfo) {
    BasicBlock *InvokeDest = II->getUnwindDest();

    Function *Caller = FirstNewBlock->getParent();

    // The inlined code is currently at the end of the function, scan from the
    // start of the inlined code to its end, checking for stuff we need to
    // rewrite.
    InvokeInliningInfo Invoke(II);

    // Get all of the inlined landing pad instructions.
    SmallPtrSet<LandingPadInst*, 16> InlinedLPads;
    for (Function::iterator I = FirstNewBlock, E = Caller->end(); I != E; ++I)
        if (InvokeInst *II = dyn_cast<InvokeInst>(I->getTerminator()))
            InlinedLPads.insert(II->getLandingPadInst());

    // Append the clauses from the outer landing pad instruction into the inlined
    // landing pad instructions.
    LandingPadInst *OuterLPad = Invoke.getLandingPadInst();
    for (SmallPtrSet<LandingPadInst*, 16>::iterator I = InlinedLPads.begin(),
            E = InlinedLPads.end(); I != E; ++I) {
        LandingPadInst *InlinedLPad = *I;
        unsigned OuterNum = OuterLPad->getNumClauses();
        InlinedLPad->reserveClauses(OuterNum);
        for (unsigned OuterIdx = 0; OuterIdx != OuterNum; ++OuterIdx)
            InlinedLPad->addClause(OuterLPad->getClause(OuterIdx));
        if (OuterLPad->isCleanup())
            InlinedLPad->setCleanup(true);
    }

    for (Function::iterator BB = FirstNewBlock, E = Caller->end(); BB != E; ++BB) {
        if (InlinedCodeInfo.ContainsCalls)
            HandleCallsInBlockInlinedThroughInvoke(BB, Invoke);

        // Forward any resumes that are remaining here.
        if (ResumeInst *RI = dyn_cast<ResumeInst>(BB->getTerminator()))
            Invoke.forwardResume(RI, InlinedLPads);
    }

    // Now that everything is happy, we have one final detail.  The PHI nodes in
    // the exception destination block still have entries due to the original
    // invoke instruction. Eliminate these entries (which might even delete the
    // PHI node) now.
    InvokeDest->removePredecessor(II->getParent());
}

/// Insert phi functions when necessary
///
void SSI::insertPhiFunctions(SmallPtrSet<Instruction*, 4> &value) {
  DominanceFrontier *DF = &getAnalysis<DominanceFrontier>();
  for (SmallPtrSet<Instruction*, 4>::iterator I = value.begin(),
       E = value.end(); I != E; ++I) {
    // Test if there were any sigmas for this variable
    SmallPtrSet<BasicBlock *, 16> BB_visited;

    // Insert phi functions if there is any sigma function
    while (!defsites[*I].empty()) {

      BasicBlock *BB = defsites[*I].back();

      defsites[*I].pop_back();
      DominanceFrontier::iterator DF_BB = DF->find(BB);

      // The BB is unreachable. Skip it.
      if (DF_BB == DF->end())
        continue; 

      // Iterates through all the dominance frontier of BB
      for (std::set<BasicBlock *>::iterator DF_BB_begin =
           DF_BB->second.begin(), DF_BB_end = DF_BB->second.end();
           DF_BB_begin != DF_BB_end; ++DF_BB_begin) {
        BasicBlock *BB_dominated = *DF_BB_begin;

        // Test if has not yet visited this node and if the
        // original definition dominates this node
        if (BB_visited.insert(BB_dominated) &&
            DT_->properlyDominates(value_original[*I], BB_dominated) &&
            dominateAny(BB_dominated, *I)) {
          PHINode *PN = PHINode::Create(
              (*I)->getType(), SSI_PHI, BB_dominated->begin());
          phis.insert(std::make_pair(PN, *I));
          created.insert(PN);

          defsites[*I].push_back(BB_dominated);
          ++NumPhiInserted;
        }
      }
    }
    BB_visited.clear();
  }
}