C++ iterator::getTerminator方法代码示例

/// HandleInlinedInvoke - If we inlined an invoke site, we need to convert calls
/// in the body of the inlined function into invokes and turn unwind
/// instructions into branches to the invoke unwind dest.
///
/// 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();
  SmallVector<Value*, 8> InvokeDestPHIValues;

  // If there are PHI nodes in the unwind destination block, we need to
  // keep track of which values came into them from this invoke, then remove
  // the entry for this block.
  BasicBlock *InvokeBlock = II->getParent();
  for (BasicBlock::iterator I = InvokeDest->begin(); isa<PHINode>(I); ++I) {
    PHINode *PN = cast<PHINode>(I);
    // Save the value to use for this edge.
    InvokeDestPHIValues.push_back(PN->getIncomingValueForBlock(InvokeBlock));
  }

  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.  If the code doesn't have calls or unwinds, we know there is
  // nothing to rewrite.
  if (!InlinedCodeInfo.ContainsCalls && !InlinedCodeInfo.ContainsUnwinds) {
    // 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());
    return;
  }
  
  for (Function::iterator BB = FirstNewBlock, E = Caller->end(); BB != E; ++BB){
    if (InlinedCodeInfo.ContainsCalls)
      HandleCallsInBlockInlinedThroughInvoke(BB, InvokeDest,
                                             InvokeDestPHIValues);

    if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) {
      // An UnwindInst requires special handling when it gets inlined into an
      // invoke site.  Once this happens, we know that the unwind would cause
      // a control transfer to the invoke exception destination, so we can
      // transform it into a direct branch to the exception destination.
      BranchInst::Create(InvokeDest, UI);

      // Delete the unwind instruction!
      UI->eraseFromParent();

      // Update any PHI nodes in the exceptional block to indicate that
      // there is now a new entry in them.
      unsigned i = 0;
      for (BasicBlock::iterator I = InvokeDest->begin();
           isa<PHINode>(I); ++I, ++i) {
        PHINode *PN = cast<PHINode>(I);
        PN->addIncoming(InvokeDestPHIValues[i], BB);
      }
    }
  }

  // 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());
}

//.........这里部分代码省略.........
    // Get the two intrinsics we care about.
    Function *StackSave = Intrinsic::getDeclaration(M, Intrinsic::stacksave);
    Function *StackRestore=Intrinsic::getDeclaration(M,Intrinsic::stackrestore);

    // If we are preserving the callgraph, add edges to the stacksave/restore
    // functions for the calls we insert.
    CallGraphNode *StackSaveCGN = 0, *StackRestoreCGN = 0, *CallerNode = 0;
    if (CallGraph *CG = IFI.CG) {
      StackSaveCGN    = CG->getOrInsertFunction(StackSave);
      StackRestoreCGN = CG->getOrInsertFunction(StackRestore);
      CallerNode = (*CG)[Caller];
    }

    // Insert the llvm.stacksave.
    CallInst *SavedPtr = CallInst::Create(StackSave, "savedstack",
                                          FirstNewBlock->begin());
    if (IFI.CG) CallerNode->addCalledFunction(SavedPtr, StackSaveCGN);

    // Insert a call to llvm.stackrestore before any return instructions in the
    // inlined function.
    for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
      CallInst *CI = CallInst::Create(StackRestore, SavedPtr, "", Returns[i]);
      if (IFI.CG) CallerNode->addCalledFunction(CI, StackRestoreCGN);
    }

    // Count the number of StackRestore calls we insert.
    unsigned NumStackRestores = Returns.size();

    // If we are inlining an invoke instruction, insert restores before each
    // unwind.  These unwinds will be rewritten into branches later.
    if (InlinedFunctionInfo.ContainsUnwinds && isa<InvokeInst>(TheCall)) {
      for (Function::iterator BB = FirstNewBlock, E = Caller->end();
           BB != E; ++BB)
        if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) {
          CallInst *CI = CallInst::Create(StackRestore, SavedPtr, "", UI);
          if (IFI.CG) CallerNode->addCalledFunction(CI, StackRestoreCGN);
          ++NumStackRestores;
        }
    }
  }

  // If we are inlining tail call instruction through a call site that isn't
  // marked 'tail', we must remove the tail marker for any calls in the inlined
  // code.  Also, calls inlined through a 'nounwind' call site should be marked
  // 'nounwind'.
  if (InlinedFunctionInfo.ContainsCalls &&
      (MustClearTailCallFlags || MarkNoUnwind)) {
    for (Function::iterator BB = FirstNewBlock, E = Caller->end();
         BB != E; ++BB)
      for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
        if (CallInst *CI = dyn_cast<CallInst>(I)) {
          if (MustClearTailCallFlags)
            CI->setTailCall(false);
          if (MarkNoUnwind)
            CI->setDoesNotThrow();
        }
  }

  // If we are inlining through a 'nounwind' call site then any inlined 'unwind'
  // instructions are unreachable.
  if (InlinedFunctionInfo.ContainsUnwinds && MarkNoUnwind)
    for (Function::iterator BB = FirstNewBlock, E = Caller->end();
         BB != E; ++BB) {
      TerminatorInst *Term = BB->getTerminator();
      if (isa<UnwindInst>(Term)) {
        new UnreachableInst(Context, Term);

bool PruneEH::runOnSCC(CallGraphSCC &SCC) {
  SmallPtrSet<CallGraphNode *, 8> SCCNodes;
  CallGraph &CG = getAnalysis<CallGraph>();
  bool MadeChange = false;

  // Fill SCCNodes with the elements of the SCC.  Used for quickly
  // looking up whether a given CallGraphNode is in this SCC.
  for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I)
    SCCNodes.insert(*I);

  // First pass, scan all of the functions in the SCC, simplifying them
  // according to what we know.
  for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I)
    if (Function *F = (*I)->getFunction())
      MadeChange |= SimplifyFunction(F);

  // Next, check to see if any callees might throw or if there are any external
  // functions in this SCC: if so, we cannot prune any functions in this SCC.
  // Definitions that are weak and not declared non-throwing might be 
  // overridden at linktime with something that throws, so assume that.
  // If this SCC includes the unwind instruction, we KNOW it throws, so
  // obviously the SCC might throw.
  //
  bool SCCMightUnwind = false, SCCMightReturn = false;
  for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); 
       (!SCCMightUnwind || !SCCMightReturn) && I != E; ++I) {
    Function *F = (*I)->getFunction();
    if (F == 0) {
      SCCMightUnwind = true;
      SCCMightReturn = true;
    } else if (F->isDeclaration() || F->mayBeOverridden()) {
      SCCMightUnwind |= !F->doesNotThrow();
      SCCMightReturn |= !F->doesNotReturn();
    } else {
      bool CheckUnwind = !SCCMightUnwind && !F->doesNotThrow();
      bool CheckReturn = !SCCMightReturn && !F->doesNotReturn();

      if (!CheckUnwind && !CheckReturn)
        continue;

      // Check to see if this function performs an unwind or calls an
      // unwinding function.
      for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
        if (CheckUnwind && isa<ResumeInst>(BB->getTerminator())) {
          // Uses unwind / resume!
          SCCMightUnwind = true;
        } else if (CheckReturn && isa<ReturnInst>(BB->getTerminator())) {
          SCCMightReturn = true;
        }

        // Invoke instructions don't allow unwinding to continue, so we are
        // only interested in call instructions.
        if (CheckUnwind && !SCCMightUnwind)
          for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
            if (CallInst *CI = dyn_cast<CallInst>(I)) {
              if (CI->doesNotThrow()) {
                // This call cannot throw.
              } else if (Function *Callee = CI->getCalledFunction()) {
                CallGraphNode *CalleeNode = CG[Callee];
                // If the callee is outside our current SCC then we may
                // throw because it might.
                if (!SCCNodes.count(CalleeNode)) {
                  SCCMightUnwind = true;
                  break;
                }
              } else {
                // Indirect call, it might throw.
                SCCMightUnwind = true;
                break;
              }
            }
        if (SCCMightUnwind && SCCMightReturn) break;
      }
    }
  }

  // If the SCC doesn't unwind or doesn't throw, note this fact.
  if (!SCCMightUnwind || !SCCMightReturn)
    for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
      AttrBuilder NewAttributes;

      if (!SCCMightUnwind)
        NewAttributes.addAttribute(Attribute::NoUnwind);
      if (!SCCMightReturn)
        NewAttributes.addAttribute(Attribute::NoReturn);

      Function *F = (*I)->getFunction();
      const AttributeSet &PAL = F->getAttributes().getFnAttributes();
      const AttributeSet &NPAL = AttributeSet::get(
          F->getContext(), AttributeSet::FunctionIndex, NewAttributes);

      if (PAL != NPAL) {
        MadeChange = true;
        F->addAttributes(AttributeSet::FunctionIndex, NPAL);
      }
    }

  for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
    // Convert any invoke instructions to non-throwing functions in this node
    // into call instructions with a branch.  This makes the exception blocks
//.........这里部分代码省略.........

bool LoaderPass::runOnModule(Module &M) {
    ProfileInfoLoader PIL("profile-loader", Filename, M);

    EdgeInformation.clear();
    std::vector<unsigned> ECs = PIL.getRawEdgeCounts();
    if (ECs.size() > 0) {
        unsigned ei = 0;
        for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
            if (F->isDeclaration()) continue;
            if (ei < ECs.size())
                EdgeInformation[F][ProfileInfo::getEdge(0, &F->getEntryBlock())] +=
                    ECs[ei++];
            for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
                // Okay, we have to add a counter of each outgoing edge.  If the
                // outgoing edge is not critical don't split it, just insert the counter
                // in the source or destination of the edge.
                TerminatorInst *TI = BB->getTerminator();
                for (unsigned s = 0, e = TI->getNumSuccessors(); s != e; ++s) {
                    if (ei < ECs.size())
                        EdgeInformation[F][ProfileInfo::getEdge(BB, TI->getSuccessor(s))] +=
                            ECs[ei++];
                }
            }
        }
        if (ei != ECs.size()) {
            cerr << "WARNING: profile information is inconsistent with "
                 << "the current program!\n";
        }
    }

    BlockInformation.clear();
    std::vector<unsigned> BCs = PIL.getRawBlockCounts();
    if (BCs.size() > 0) {
        unsigned bi = 0;
        for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
            if (F->isDeclaration()) continue;
            for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
                if (bi < BCs.size())
                    BlockInformation[F][BB] = BCs[bi++];
        }
        if (bi != BCs.size()) {
            cerr << "WARNING: profile information is inconsistent with "
                 << "the current program!\n";
        }
    }

    FunctionInformation.clear();
    std::vector<unsigned> FCs = PIL.getRawFunctionCounts();
    if (FCs.size() > 0) {
        unsigned fi = 0;
        for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
            if (F->isDeclaration()) continue;
            if (fi < FCs.size())
                FunctionInformation[F] = FCs[fi++];
        }
        if (fi != FCs.size()) {
            cerr << "WARNING: profile information is inconsistent with "
                 << "the current program!\n";
        }
    }

    return false;
}

// the verifier iterates through each path to gather the total
// number of edge frequencies
bool PathProfileVerifier::runOnModule (Module &M) {
    PathProfileInfo& pathProfileInfo = getAnalysis<PathProfileInfo>();

    // setup a data structure to map path edges which index an
    // array of edge counters
    NestedBlockToIndexMap arrayMap;
    unsigned i = 0;
    for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
        if (F->isDeclaration()) continue;

        arrayMap[0][F->begin()][0] = i++;

        for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
            TerminatorInst *TI = BB->getTerminator();

            unsigned duplicate = 0;
            BasicBlock* prev = 0;
            for (unsigned s = 0, e = TI->getNumSuccessors(); s != e;
                    prev = TI->getSuccessor(s), ++s) {
                if (prev == TI->getSuccessor(s))
                    duplicate++;
                else duplicate = 0;

                arrayMap[BB][TI->getSuccessor(s)][duplicate] = i++;
            }
        }
    }

    std::vector<unsigned> edgeArray(i);

    // iterate through each path and increment the edge counters as needed
    for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
        if (F->isDeclaration()) continue;

        pathProfileInfo.setCurrentFunction(F);

        DEBUG(dbgs() << "function '" << F->getName() << "' ran "
              << pathProfileInfo.pathsRun()
              << "/" << pathProfileInfo.getPotentialPathCount()
              << " potential paths\n");

        for( ProfilePathIterator nextPath = pathProfileInfo.pathBegin(),
                endPath = pathProfileInfo.pathEnd();
                nextPath != endPath; nextPath++ ) {
            ProfilePath* currentPath = nextPath->second;

            ProfilePathEdgeVector* pev = currentPath->getPathEdges();
            DEBUG(dbgs () << "path #" << currentPath->getNumber() << ": "
                  << currentPath->getCount() << "\n");
            // setup the entry edge (normally path profiling doesn't care about this)
            if (currentPath->getFirstBlockInPath() == &F->getEntryBlock())
                edgeArray[arrayMap[0][currentPath->getFirstBlockInPath()][0]]
                += currentPath->getCount();

            for( ProfilePathEdgeIterator nextEdge = pev->begin(),
                    endEdge = pev->end(); nextEdge != endEdge; nextEdge++ ) {
                if (nextEdge != pev->begin())
                    DEBUG(dbgs() << " :: ");

                BasicBlock* source = nextEdge->getSource();
                BasicBlock* target = nextEdge->getTarget();
                unsigned duplicateNumber = nextEdge->getDuplicateNumber();
                DEBUG(dbgs () << source->getNameStr() << " --{" << duplicateNumber
                      << "}--> " << target->getNameStr());

                // Ensure all the referenced edges exist
                // TODO: make this a separate function
                if( !arrayMap.count(source) ) {
                    errs() << "  error [" << F->getNameStr() << "()]: source '"
                           << source->getNameStr()
                           << "' does not exist in the array map.\n";
                } else if( !arrayMap[source].count(target) ) {
                    errs() << "  error [" << F->getNameStr() << "()]: target '"
                           << target->getNameStr()
                           << "' does not exist in the array map.\n";
                } else if( !arrayMap[source][target].count(duplicateNumber) ) {
                    errs() << "  error [" << F->getNameStr() << "()]: edge "
                           << source->getNameStr() << " -> " << target->getNameStr()
                           << " duplicate number " << duplicateNumber
                           << " does not exist in the array map.\n";
                } else {
                    edgeArray[arrayMap[source][target][duplicateNumber]]
                    += currentPath->getCount();
                }
            }

            DEBUG(errs() << "\n");

            delete pev;
        }
    }

    std::string errorInfo;
    std::string filename = EdgeProfileFilename;

    // Open a handle to the file
    FILE* edgeFile = fopen(filename.c_str(),"wb");

//.........这里部分代码省略.........

/// NormalizeLandingPads - Normalize and discover landing pads, noting them
/// in the LandingPads set.  A landing pad is normal if the only CFG edges
/// that end at it are unwind edges from invoke instructions. If we inlined
/// through an invoke we could have a normal branch from the previous
/// unwind block through to the landing pad for the original invoke.
/// Abnormal landing pads are fixed up by redirecting all unwind edges to
/// a new basic block which falls through to the original.
bool DwarfEHPrepare::NormalizeLandingPads() {
  bool Changed = false;

  const MCAsmInfo *MAI = TM->getMCAsmInfo();
  bool usingSjLjEH = MAI->getExceptionHandlingType() == ExceptionHandling::SjLj;

  for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {
    TerminatorInst *TI = I->getTerminator();
    if (!isa<InvokeInst>(TI))
      continue;
    BasicBlock *LPad = TI->getSuccessor(1);
    // Skip landing pads that have already been normalized.
    if (LandingPads.count(LPad))
      continue;

    // Check that only invoke unwind edges end at the landing pad.
    bool OnlyUnwoundTo = true;
    bool SwitchOK = usingSjLjEH;
    for (pred_iterator PI = pred_begin(LPad), PE = pred_end(LPad);
         PI != PE; ++PI) {
      TerminatorInst *PT = (*PI)->getTerminator();
      // The SjLj dispatch block uses a switch instruction. This is effectively
      // an unwind edge, so we can disregard it here. There will only ever
      // be one dispatch, however, so if there are multiple switches, one
      // of them truly is a normal edge, not an unwind edge.
      if (SwitchOK && isa<SwitchInst>(PT)) {
        SwitchOK = false;
        continue;
      }
      if (!isa<InvokeInst>(PT) || LPad == PT->getSuccessor(0)) {
        OnlyUnwoundTo = false;
        break;
      }
    }

    if (OnlyUnwoundTo) {
      // Only unwind edges lead to the landing pad.  Remember the landing pad.
      LandingPads.insert(LPad);
      continue;
    }

    // At least one normal edge ends at the landing pad.  Redirect the unwind
    // edges to a new basic block which falls through into this one.

    // Create the new basic block.
    BasicBlock *NewBB = BasicBlock::Create(F->getContext(),
                                           LPad->getName() + "_unwind_edge");

    // Insert it into the function right before the original landing pad.
    LPad->getParent()->getBasicBlockList().insert(LPad, NewBB);

    // Redirect unwind edges from the original landing pad to NewBB.
    for (pred_iterator PI = pred_begin(LPad), PE = pred_end(LPad); PI != PE; ) {
      TerminatorInst *PT = (*PI++)->getTerminator();
      if (isa<InvokeInst>(PT) && PT->getSuccessor(1) == LPad)
        // Unwind to the new block.
        PT->setSuccessor(1, NewBB);
    }

    // If there are any PHI nodes in LPad, we need to update them so that they
    // merge incoming values from NewBB instead.
    for (BasicBlock::iterator II = LPad->begin(); isa<PHINode>(II); ++II) {
      PHINode *PN = cast<PHINode>(II);
      pred_iterator PB = pred_begin(NewBB), PE = pred_end(NewBB);

      // Check to see if all of the values coming in via unwind edges are the
      // same.  If so, we don't need to create a new PHI node.
      Value *InVal = PN->getIncomingValueForBlock(*PB);
      for (pred_iterator PI = PB; PI != PE; ++PI) {
        if (PI != PB && InVal != PN->getIncomingValueForBlock(*PI)) {
          InVal = 0;
          break;
        }
      }

      if (InVal == 0) {
        // Different unwind edges have different values.  Create a new PHI node
        // in NewBB.
        PHINode *NewPN = PHINode::Create(PN->getType(), PN->getName()+".unwind",
                                         NewBB);
        // Add an entry for each unwind edge, using the value from the old PHI.
        for (pred_iterator PI = PB; PI != PE; ++PI)
          NewPN->addIncoming(PN->getIncomingValueForBlock(*PI), *PI);

        // Now use this new PHI as the common incoming value for NewBB in PN.
        InVal = NewPN;
      }

      // Revector exactly one entry in the PHI node to come from NewBB
      // and delete all other entries that come from unwind edges.  If
      // there are both normal and unwind edges from the same predecessor,
      // this leaves an entry for the normal edge.
      for (pred_iterator PI = PB; PI != PE; ++PI)
//.........这里部分代码省略.........

//.........这里部分代码省略.........
  // create the new entry block, allowing us to branch back to the old entry.
  if (OldEntry == 0) {
    OldEntry = &F->getEntryBlock();
    BasicBlock *NewEntry = BasicBlock::Create(F->getContext(), "", F, OldEntry);
    NewEntry->takeName(OldEntry);
    OldEntry->setName("tailrecurse");
    BranchInst::Create(OldEntry, NewEntry);

    // If this tail call is marked 'tail' and if there are any allocas in the
    // entry block, move them up to the new entry block.
    TailCallsAreMarkedTail = CI->isTailCall();
    if (TailCallsAreMarkedTail)
      // Move all fixed sized allocas from OldEntry to NewEntry.
      for (BasicBlock::iterator OEBI = OldEntry->begin(), E = OldEntry->end(),
             NEBI = NewEntry->begin(); OEBI != E; )
        if (AllocaInst *AI = dyn_cast<AllocaInst>(OEBI++))
          if (isa<ConstantInt>(AI->getArraySize()))
            AI->moveBefore(NEBI);

    // Now that we have created a new block, which jumps to the entry
    // block, insert a PHI node for each argument of the function.
    // For now, we initialize each PHI to only have the real arguments
    // which are passed in.
    Instruction *InsertPos = OldEntry->begin();
    for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end();
         I != E; ++I) {
      PHINode *PN = PHINode::Create(I->getType(),
                                    I->getName() + ".tr", InsertPos);
      I->replaceAllUsesWith(PN); // Everyone use the PHI node now!
      PN->addIncoming(I, NewEntry);
      ArgumentPHIs.push_back(PN);
    }
  }

  // If this function has self recursive calls in the tail position where some
  // are marked tail and some are not, only transform one flavor or another.  We
  // have to choose whether we move allocas in the entry block to the new entry
  // block or not, so we can't make a good choice for both.  NOTE: We could do
  // slightly better here in the case that the function has no entry block
  // allocas.
  if (TailCallsAreMarkedTail && !CI->isTailCall())
    return false;

  // Ok, now that we know we have a pseudo-entry block WITH all of the
  // required PHI nodes, add entries into the PHI node for the actual
  // parameters passed into the tail-recursive call.
  for (unsigned i = 0, e = CI->getNumOperands()-1; i != e; ++i)
    ArgumentPHIs[i]->addIncoming(CI->getOperand(i+1), BB);

  // If we are introducing an accumulator variable to eliminate the recursion,
  // do so now.  Note that we _know_ that no subsequent tail recursion
  // eliminations will happen on this function because of the way the
  // accumulator recursion predicate is set up.
  //
  if (AccumulatorRecursionEliminationInitVal) {
    Instruction *AccRecInstr = AccumulatorRecursionInstr;
    // Start by inserting a new PHI node for the accumulator.
    PHINode *AccPN = PHINode::Create(AccRecInstr->getType(), "accumulator.tr",
                                     OldEntry->begin());

    // Loop over all of the predecessors of the tail recursion block.  For the
    // real entry into the function we seed the PHI with the initial value,
    // computed earlier.  For any other existing branches to this block (due to
    // other tail recursions eliminated) the accumulator is not modified.
    // Because we haven't added the branch in the current block to OldEntry yet,
    // it will not show up as a predecessor.
    for (pred_iterator PI = pred_begin(OldEntry), PE = pred_end(OldEntry);
         PI != PE; ++PI) {
      if (*PI == &F->getEntryBlock())
        AccPN->addIncoming(AccumulatorRecursionEliminationInitVal, *PI);
      else
        AccPN->addIncoming(AccPN, *PI);
    }

    // Add an incoming argument for the current block, which is computed by our
    // associative accumulator instruction.
    AccPN->addIncoming(AccRecInstr, BB);

    // Next, rewrite the accumulator recursion instruction so that it does not
    // use the result of the call anymore, instead, use the PHI node we just
    // inserted.
    AccRecInstr->setOperand(AccRecInstr->getOperand(0) != CI, AccPN);

    // Finally, rewrite any return instructions in the program to return the PHI
    // node instead of the "initval" that they do currently.  This loop will
    // actually rewrite the return value we are destroying, but that's ok.
    for (Function::iterator BBI = F->begin(), E = F->end(); BBI != E; ++BBI)
      if (ReturnInst *RI = dyn_cast<ReturnInst>(BBI->getTerminator()))
        RI->setOperand(0, AccPN);
    ++NumAccumAdded;
  }

  // Now that all of the PHI nodes are in place, remove the call and
  // ret instructions, replacing them with an unconditional branch.
  BranchInst::Create(OldEntry, Ret);
  BB->getInstList().erase(Ret);  // Remove return.
  BB->getInstList().erase(CI);   // Remove call.
  ++NumEliminated;
  return true;
}

bool LoaderPass::runOnModule(Module &M) {
  ProfileInfoLoader PIL("profile-loader", Filename);

  EdgeInformation.clear();
  std::vector<unsigned> Counters = PIL.getRawEdgeCounts();
  if (Counters.size() > 0) {
    ReadCount = 0;
    for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
      if (F->isDeclaration()) continue;
      DEBUG(dbgs() << "Working on " << F->getName() << "\n");
      readEdge(getEdge(0,&F->getEntryBlock()), Counters);
      for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
        TerminatorInst *TI = BB->getTerminator();
        for (unsigned s = 0, e = TI->getNumSuccessors(); s != e; ++s) {
          readEdge(getEdge(BB,TI->getSuccessor(s)), Counters);
        }
      }
    }
    if (ReadCount != Counters.size()) {
      errs() << "WARNING: profile information is inconsistent with "
             << "the current program!\n";
    }
    NumEdgesRead = ReadCount;
  }

  Counters = PIL.getRawOptimalEdgeCounts();
  if (Counters.size() > 0) {
    ReadCount = 0;
    for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
      if (F->isDeclaration()) continue;
      DEBUG(dbgs() << "Working on " << F->getName() << "\n");
      readEdge(getEdge(0,&F->getEntryBlock()), Counters);
      for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
        TerminatorInst *TI = BB->getTerminator();
        if (TI->getNumSuccessors() == 0) {
          readEdge(getEdge(BB,0), Counters);
        }
        for (unsigned s = 0, e = TI->getNumSuccessors(); s != e; ++s) {
          readEdge(getEdge(BB,TI->getSuccessor(s)), Counters);
        }
      }
      while (SpanningTree.size() > 0) {

        unsigned size = SpanningTree.size();

        BBisUnvisited.clear();
        for (std::set<Edge>::iterator ei = SpanningTree.begin(),
             ee = SpanningTree.end(); ei != ee; ++ei) {
          BBisUnvisited.insert(ei->first);
          BBisUnvisited.insert(ei->second);
        }
        while (BBisUnvisited.size() > 0) {
          recurseBasicBlock(*BBisUnvisited.begin());
        }

        if (SpanningTree.size() == size) {
          DEBUG(dbgs()<<"{");
          for (std::set<Edge>::iterator ei = SpanningTree.begin(),
               ee = SpanningTree.end(); ei != ee; ++ei) {
            DEBUG(dbgs()<< *ei <<",");
          }
          assert(0 && "No edge calculated!");
        }

      }
    }
    if (ReadCount != Counters.size()) {
      errs() << "WARNING: profile information is inconsistent with "
             << "the current program!\n";
    }
    NumEdgesRead = ReadCount;
  }

  BlockInformation.clear();
  Counters = PIL.getRawBlockCounts();
  if (Counters.size() > 0) {
    ReadCount = 0;
    for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
      if (F->isDeclaration()) continue;
      for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
        if (ReadCount < Counters.size())
          // Here the data realm changes from the unsigned of the file to the
          // double of the ProfileInfo. This conversion is save because we know
          // that everything thats representable in unsinged is also
          // representable in double.
          BlockInformation[F][BB] = (double)Counters[ReadCount++];
    }
    if (ReadCount != Counters.size()) {
      errs() << "WARNING: profile information is inconsistent with "
             << "the current program!\n";
    }
  }

  FunctionInformation.clear();
  Counters = PIL.getRawFunctionCounts();
  if (Counters.size() > 0) {
    ReadCount = 0;
    for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
      if (F->isDeclaration()) continue;
      if (ReadCount < Counters.size())
//.........这里部分代码省略.........

bool TailCallElim::runOnFunction(Function &F) {
  // If this function is a varargs function, we won't be able to PHI the args
  // right, so don't even try to convert it...
  if (F.getFunctionType()->isVarArg()) return false;

  BasicBlock *OldEntry = 0;
  bool TailCallsAreMarkedTail = false;
  SmallVector<PHINode*, 8> ArgumentPHIs;
  bool MadeChange = false;

  bool FunctionContainsEscapingAllocas = false;

  // CannotTCETailMarkedCall - If true, we cannot perform TCE on tail calls
  // marked with the 'tail' attribute, because doing so would cause the stack
  // size to increase (real TCE would deallocate variable sized allocas, TCE
  // doesn't).
  bool CannotTCETailMarkedCall = false;

  // Loop over the function, looking for any returning blocks, and keeping track
  // of whether this function has any non-trivially used allocas.
  for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
    if (FunctionContainsEscapingAllocas && CannotTCETailMarkedCall)
      break;

    FunctionContainsEscapingAllocas |=
      CheckForEscapingAllocas(BB, CannotTCETailMarkedCall);
  }
  
  /// FIXME: The code generator produces really bad code when an 'escaping
  /// alloca' is changed from being a static alloca to being a dynamic alloca.
  /// Until this is resolved, disable this transformation if that would ever
  /// happen.  This bug is PR962.
  if (FunctionContainsEscapingAllocas)
    return false;

  // Second pass, change any tail calls to loops.
  for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
    if (ReturnInst *Ret = dyn_cast<ReturnInst>(BB->getTerminator()))
      MadeChange |= ProcessReturningBlock(Ret, OldEntry, TailCallsAreMarkedTail,
                                          ArgumentPHIs,CannotTCETailMarkedCall);

  // If we eliminated any tail recursions, it's possible that we inserted some
  // silly PHI nodes which just merge an initial value (the incoming operand)
  // with themselves.  Check to see if we did and clean up our mess if so.  This
  // occurs when a function passes an argument straight through to its tail
  // call.
  if (!ArgumentPHIs.empty()) {
    for (unsigned i = 0, e = ArgumentPHIs.size(); i != e; ++i) {
      PHINode *PN = ArgumentPHIs[i];

      // If the PHI Node is a dynamic constant, replace it with the value it is.
      if (Value *PNV = PN->hasConstantValue()) {
        PN->replaceAllUsesWith(PNV);
        PN->eraseFromParent();
      }
    }
  }

  // Finally, if this function contains no non-escaping allocas, mark all calls
  // in the function as eligible for tail calls (there is no stack memory for
  // them to access).
  if (!FunctionContainsEscapingAllocas)
    for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
      for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
        if (CallInst *CI = dyn_cast<CallInst>(I)) {
          CI->setTailCall();
          MadeChange = true;
        }

  return MadeChange;
}

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

  // Convert list to set for fast lookup...
  SmallPtrSet<BasicBlock*, 8> Blocks;
  for (unsigned i = 0, e = BBs.size(); i != e; ++i)
    Blocks.insert(cast<BasicBlock>(VMap[BBs[i]]));

  outs() << "Checking for crash with only these blocks:";
  unsigned NumPrint = Blocks.size();
  if (NumPrint > 10) NumPrint = 10;
  for (unsigned i = 0, e = NumPrint; i != e; ++i)
    outs() << " " << BBs[i]->getName();
  if (NumPrint < Blocks.size())
    outs() << "... <" << Blocks.size() << " total>";
  outs() << ": ";

  // Loop over and delete any hack up any blocks that are not listed...
  for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
    for (Function::iterator BB = I->begin(), E = I->end(); BB != E; ++BB)
      if (!Blocks.count(BB) && BB->getTerminator()->getNumSuccessors()) {
        // Loop over all of the successors of this block, deleting any PHI nodes
        // that might include it.
        for (succ_iterator SI = succ_begin(BB), E = succ_end(BB); SI != E; ++SI)
          (*SI)->removePredecessor(BB);

        TerminatorInst *BBTerm = BB->getTerminator();
        
        if (!BB->getTerminator()->getType()->isVoidTy())
          BBTerm->replaceAllUsesWith(Constant::getNullValue(BBTerm->getType()));

        // Replace the old terminator instruction.
        BB->getInstList().pop_back();
        new UnreachableInst(BB->getContext(), BB);
      }

  // The CFG Simplifier pass may delete one of the basic blocks we are
  // interested in.  If it does we need to take the block out of the list.  Make
  // a "persistent mapping" by turning basic blocks into <function, name> pairs.
  // This won't work well if blocks are unnamed, but that is just the risk we
  // have to take.
  std::vector<std::pair<std::string, std::string> > BlockInfo;

  for (SmallPtrSet<BasicBlock*, 8>::iterator I = Blocks.begin(),
         E = Blocks.end(); I != E; ++I)
    BlockInfo.push_back(std::make_pair((*I)->getParent()->getName(),
                                       (*I)->getName()));

  // Now run the CFG simplify pass on the function...
  std::vector<std::string> Passes;
  Passes.push_back("simplifycfg");
  Passes.push_back("verify");
  Module *New = BD.runPassesOn(M, Passes);
  delete M;
  if (!New) {
    errs() << "simplifycfg failed!\n";
    exit(1);
  }
  M = New;

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

    // Make sure to use basic block pointers that point into the now-current
    // module, and that they don't include any deleted blocks.
    BBs.clear();
    const ValueSymbolTable &GST = M->getValueSymbolTable();
    for (unsigned i = 0, e = BlockInfo.size(); i != e; ++i) {
      Function *F = cast<Function>(GST.lookup(BlockInfo[i].first));
      ValueSymbolTable &ST = F->getValueSymbolTable();
      Value* V = ST.lookup(BlockInfo[i].second);
      if (V && V->getType() == Type::getLabelTy(V->getContext()))
        BBs.push_back(cast<BasicBlock>(V));
    }
    return true;
  }
  delete M;  // It didn't crash, try something else.
  return false;
}

void StructFieldReach::InitBeforeAfterSet(Function * pF)
{
	for(Function::iterator BB = pF->begin(); BB != pF->end(); BB++)
	{
		for(BasicBlock::iterator II = BB->begin(); II != BB->end(); II ++)
		{
			vector<Instruction *> vecPredInst;
			this->InstPredInstVecMapping[II] = vecPredInst;

			vector<Instruction *> vecSuccInst;
			this->InstSuccInstVecMapping[II] = vecSuccInst;


			set<MemFootPrint *> beforeSet;
			this->InstBeforeSetMapping[II] = beforeSet;

			set<MemFootPrint *> afterSet;
			this->InstAfterSetMapping[II] = afterSet;

			set<MemFootPrint *> beforeExtendSet;
			this->InstBeforeExtendSetMapping[II] = beforeExtendSet;

			set<MemFootPrint *> afterExtendSet;
			this->InstAfterExtendSetMapping[II] = afterExtendSet;

		}
	}

	for(Function::iterator BB = pF->begin(); BB != pF->end(); BB ++)
	{
		BasicBlock::iterator itFirstInst = BB->begin();

		if(itFirstInst == BB->end() )
		{
			continue;
		}

		for(pred_iterator pred = pred_begin(BB); pred != pred_end(BB); pred++ )
		{
			this->InstPredInstVecMapping[itFirstInst].push_back((*pred)->getTerminator());
		}

		BasicBlock::iterator itLastInst = BB->getTerminator();
		for(succ_iterator succ = succ_begin(BB); succ != succ_end(BB); succ++ )
		{
			if((*succ)->begin() == (*succ)->end())
			{
				continue;
			}
			this->InstSuccInstVecMapping[itLastInst].push_back((*succ)->begin());
		}

		for(BasicBlock::iterator II = BB->begin(); II != BB->end(); II ++)
		{
			BasicBlock::iterator ITmp;
			if(II != BB->begin())
			{
				ITmp = II;
				ITmp--;
				this->InstPredInstVecMapping[II].push_back(ITmp);
			}

			ITmp = II;
			ITmp ++;

			if(ITmp != BB->end() )
			{
				this->InstSuccInstVecMapping[II].push_back(ITmp);
			}
		}
	}
}

/// Tests whether a function is "malloc-like".
///
/// A function is "malloc-like" if it returns either null or a pointer that
/// doesn't alias any other pointer visible to the caller.
static bool isFunctionMallocLike(Function *F, const SCCNodeSet &SCCNodes) {
  SmallSetVector<Value *, 8> FlowsToReturn;
  for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I)
    if (ReturnInst *Ret = dyn_cast<ReturnInst>(I->getTerminator()))
      FlowsToReturn.insert(Ret->getReturnValue());

  for (unsigned i = 0; i != FlowsToReturn.size(); ++i) {
    Value *RetVal = FlowsToReturn[i];

    if (Constant *C = dyn_cast<Constant>(RetVal)) {
      if (!C->isNullValue() && !isa<UndefValue>(C))
        return false;

      continue;
    }

    if (isa<Argument>(RetVal))
      return false;

    if (Instruction *RVI = dyn_cast<Instruction>(RetVal))
      switch (RVI->getOpcode()) {
      // Extend the analysis by looking upwards.
      case Instruction::BitCast:
      case Instruction::GetElementPtr:
      case Instruction::AddrSpaceCast:
        FlowsToReturn.insert(RVI->getOperand(0));
        continue;
      case Instruction::Select: {
        SelectInst *SI = cast<SelectInst>(RVI);
        FlowsToReturn.insert(SI->getTrueValue());
        FlowsToReturn.insert(SI->getFalseValue());
        continue;
      }
      case Instruction::PHI: {
        PHINode *PN = cast<PHINode>(RVI);
        for (Value *IncValue : PN->incoming_values())
          FlowsToReturn.insert(IncValue);
        continue;
      }

      // Check whether the pointer came from an allocation.
      case Instruction::Alloca:
        break;
      case Instruction::Call:
      case Instruction::Invoke: {
        CallSite CS(RVI);
        if (CS.paramHasAttr(0, Attribute::NoAlias))
          break;
        if (CS.getCalledFunction() && SCCNodes.count(CS.getCalledFunction()))
          break;
      } // fall-through
      default:
        return false; // Did not come from an allocation.
      }

    if (PointerMayBeCaptured(RetVal, false, /*StoreCaptures=*/false))
      return false;
  }

  return true;
}

/// setupEntryBlockAndCallSites - Setup the entry block by creating and filling
/// the function context and marking the call sites with the appropriate
/// values. These values are used by the DWARF EH emitter.
bool SjLjEHPrepare::setupEntryBlockAndCallSites(Function &F) {
  SmallVector<ReturnInst *, 16> Returns;
  SmallVector<InvokeInst *, 16> Invokes;
  SmallSetVector<LandingPadInst *, 16> LPads;

  // Look through the terminators of the basic blocks to find invokes.
  for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
    if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator())) {
      if (Function *Callee = II->getCalledFunction())
        if (Callee->isIntrinsic() &&
            Callee->getIntrinsicID() == Intrinsic::donothing) {
          // Remove the NOP invoke.
          BranchInst::Create(II->getNormalDest(), II);
          II->eraseFromParent();
          continue;
        }

      Invokes.push_back(II);
      LPads.insert(II->getUnwindDest()->getLandingPadInst());
    } else if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) {
      Returns.push_back(RI);
    }

  if (Invokes.empty())
    return false;

  NumInvokes += Invokes.size();

  lowerIncomingArguments(F);
  lowerAcrossUnwindEdges(F, Invokes);

  Value *FuncCtx =
      setupFunctionContext(F, makeArrayRef(LPads.begin(), LPads.end()));
  BasicBlock *EntryBB = F.begin();
  IRBuilder<> Builder(EntryBB->getTerminator());

  // Get a reference to the jump buffer.
  Value *JBufPtr = Builder.CreateConstGEP2_32(FuncCtx, 0, 5, "jbuf_gep");

  // Save the frame pointer.
  Value *FramePtr = Builder.CreateConstGEP2_32(JBufPtr, 0, 0, "jbuf_fp_gep");

  Value *Val = Builder.CreateCall(FrameAddrFn, Builder.getInt32(0), "fp");
  Builder.CreateStore(Val, FramePtr, /*isVolatile=*/true);

  // Save the stack pointer.
  Value *StackPtr = Builder.CreateConstGEP2_32(JBufPtr, 0, 2, "jbuf_sp_gep");

  Val = Builder.CreateCall(StackAddrFn, "sp");
  Builder.CreateStore(Val, StackPtr, /*isVolatile=*/true);

  // Call the setjmp instrinsic. It fills in the rest of the jmpbuf.
  Value *SetjmpArg = Builder.CreateBitCast(JBufPtr, Builder.getInt8PtrTy());
  Builder.CreateCall(BuiltinSetjmpFn, SetjmpArg);

  // Store a pointer to the function context so that the back-end will know
  // where to look for it.
  Value *FuncCtxArg = Builder.CreateBitCast(FuncCtx, Builder.getInt8PtrTy());
  Builder.CreateCall(FuncCtxFn, FuncCtxArg);

  // At this point, we are all set up, update the invoke instructions to mark
  // their call_site values.
  for (unsigned I = 0, E = Invokes.size(); I != E; ++I) {
    insertCallSiteStore(Invokes[I], I + 1);

    ConstantInt *CallSiteNum =
        ConstantInt::get(Type::getInt32Ty(F.getContext()), I + 1);

    // Record the call site value for the back end so it stays associated with
    // the invoke.
    CallInst::Create(CallSiteFn, CallSiteNum, "", Invokes[I]);
  }

  // Mark call instructions that aren't nounwind as no-action (call_site ==
  // -1). Skip the entry block, as prior to then, no function context has been
  // created for this function and any unexpected exceptions thrown will go
  // directly to the caller's context, which is what we want anyway, so no need
  // to do anything here.
  for (Function::iterator BB = F.begin(), E = F.end(); ++BB != E;)
    for (BasicBlock::iterator I = BB->begin(), end = BB->end(); I != end; ++I)
      if (CallInst *CI = dyn_cast<CallInst>(I)) {
        if (!CI->doesNotThrow())
          insertCallSiteStore(CI, -1);
      } else if (ResumeInst *RI = dyn_cast<ResumeInst>(I)) {
        insertCallSiteStore(RI, -1);
      }

  // Register the function context and make sure it's known to not throw
  CallInst *Register =
      CallInst::Create(RegisterFn, FuncCtx, "", EntryBB->getTerminator());
  Register->setDoesNotThrow();

  // Following any allocas not in the entry block, update the saved SP in the
  // jmpbuf to the new value.
  for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
    if (BB == F.begin())
      continue;
//.........这里部分代码省略.........