PassManager.cpp

//===- PassManager.cpp - LLVM Pass Infrastructure Implementation ----------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the LLVM Pass Manager infrastructure.
//
//===----------------------------------------------------------------------===//


#include "llvm/PassManagers.h"
#include "llvm/Assembly/PrintModulePass.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/IR/Module.h"
#include "llvm/PassManager.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/Mutex.h"
#include "llvm/Support/PassNameParser.h"
#include "llvm/Support/Timer.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <map>
using namespace llvm;

// See PassManagers.h for Pass Manager infrastructure overview.

namespace llvm {

//===----------------------------------------------------------------------===//
// Pass debugging information.  Often it is useful to find out what pass is
// running when a crash occurs in a utility.  When this library is compiled with
// debugging on, a command line option (--debug-pass) is enabled that causes the
// pass name to be printed before it executes.
//

// Different debug levels that can be enabled...
enum PassDebugLevel {
  None, Arguments, Structure, Executions, Details
};

static cl::opt<enum PassDebugLevel>
PassDebugging("debug-pass", cl::Hidden,
                  cl::desc("Print PassManager debugging information"),
                  cl::values(
  clEnumVal(None      , "disable debug output"),
  clEnumVal(Arguments , "print pass arguments to pass to 'opt'"),
  clEnumVal(Structure , "print pass structure before run()"),
  clEnumVal(Executions, "print pass name before it is executed"),
  clEnumVal(Details   , "print pass details when it is executed"),
                             clEnumValEnd));

typedef llvm::cl::list<const llvm::PassInfo *, bool, PassNameParser>
PassOptionList;

// Print IR out before/after specified passes.
static PassOptionList
PrintBefore("print-before",
            llvm::cl::desc("Print IR before specified passes"),
            cl::Hidden);

static PassOptionList
PrintAfter("print-after",
           llvm::cl::desc("Print IR after specified passes"),
           cl::Hidden);

static cl::opt<bool>
PrintBeforeAll("print-before-all",
               llvm::cl::desc("Print IR before each pass"),
               cl::init(false));
static cl::opt<bool>
PrintAfterAll("print-after-all",
              llvm::cl::desc("Print IR after each pass"),
              cl::init(false));

/// This is a helper to determine whether to print IR before or
/// after a pass.

static bool ShouldPrintBeforeOrAfterPass(const PassInfo *PI,
                                         PassOptionList &PassesToPrint) {
  for (unsigned i = 0, ie = PassesToPrint.size(); i < ie; ++i) {
    const llvm::PassInfo *PassInf = PassesToPrint[i];
    if (PassInf)
      if (PassInf->getPassArgument() == PI->getPassArgument()) {
        return true;
      }
  }
  return false;
}

/// This is a utility to check whether a pass should have IR dumped
/// before it.
static bool ShouldPrintBeforePass(const PassInfo *PI) {
  return PrintBeforeAll || ShouldPrintBeforeOrAfterPass(PI, PrintBefore);
}

/// This is a utility to check whether a pass should have IR dumped
/// after it.
static bool ShouldPrintAfterPass(const PassInfo *PI) {
  return PrintAfterAll || ShouldPrintBeforeOrAfterPass(PI, PrintAfter);
}

} // End of llvm namespace

/// isPassDebuggingExecutionsOrMore - Return true if -debug-pass=Executions
/// or higher is specified.
bool PMDataManager::isPassDebuggingExecutionsOrMore() const {
  return PassDebugging >= Executions;
}




void PassManagerPrettyStackEntry::print(raw_ostream &OS) const {
  if (V == 0 && M == 0)
    OS << "Releasing pass '";
  else
    OS << "Running pass '";

  OS << P->getPassName() << "'";

  if (M) {
    OS << " on module '" << M->getModuleIdentifier() << "'.\n";
    return;
  }
  if (V == 0) {
    OS << '\n';
    return;
  }

  OS << " on ";
  if (isa<Function>(V))
    OS << "function";
  else if (isa<BasicBlock>(V))
    OS << "basic block";
  else
    OS << "value";

  OS << " '";
  WriteAsOperand(OS, V, /*PrintTy=*/false, M);
  OS << "'\n";
}


namespace {

//===----------------------------------------------------------------------===//
// BBPassManager
//
/// BBPassManager manages BasicBlockPass. It batches all the
/// pass together and sequence them to process one basic block before
/// processing next basic block.
class BBPassManager : public PMDataManager, public FunctionPass {

public:
  static char ID;
  explicit BBPassManager()
    : PMDataManager(), FunctionPass(ID) {}

  /// Execute all of the passes scheduled for execution.  Keep track of
  /// whether any of the passes modifies the function, and if so, return true.
  bool runOnFunction(Function &F);

  /// Pass Manager itself does not invalidate any analysis info.
  void getAnalysisUsage(AnalysisUsage &Info) const {
    Info.setPreservesAll();
  }

  bool doInitialization(Module &M);
  bool doInitialization(Function &F);
  bool doFinalization(Module &M);
  bool doFinalization(Function &F);

  virtual PMDataManager *getAsPMDataManager() { return this; }
  virtual Pass *getAsPass() { return this; }

  virtual const char *getPassName() const {
    return "BasicBlock Pass Manager";
  }

  // Print passes managed by this manager
  void dumpPassStructure(unsigned Offset) {
    llvm::dbgs().indent(Offset*2) << "BasicBlockPass Manager\n";
    for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
      BasicBlockPass *BP = getContainedPass(Index);
      BP->dumpPassStructure(Offset + 1);
      dumpLastUses(BP, Offset+1);
    }
  }

  BasicBlockPass *getContainedPass(unsigned N) {
    assert(N < PassVector.size() && "Pass number out of range!");
    BasicBlockPass *BP = static_cast<BasicBlockPass *>(PassVector[N]);
    return BP;
  }

  virtual PassManagerType getPassManagerType() const {
    return PMT_BasicBlockPassManager;
  }
};

char BBPassManager::ID = 0;
}

namespace llvm {

//===----------------------------------------------------------------------===//
// FunctionPassManagerImpl
//
/// FunctionPassManagerImpl manages FPPassManagers
class FunctionPassManagerImpl : public Pass,
                                public PMDataManager,
                                public PMTopLevelManager {
  virtual void anchor();
private:
  bool wasRun;
public:
  static char ID;
  explicit FunctionPassManagerImpl() :
    Pass(PT_PassManager, ID), PMDataManager(),
    PMTopLevelManager(new FPPassManager()), wasRun(false) {}

  /// add - Add a pass to the queue of passes to run.  This passes ownership of
  /// the Pass to the PassManager.  When the PassManager is destroyed, the pass
  /// will be destroyed as well, so there is no need to delete the pass.  This
  /// implies that all passes MUST be allocated with 'new'.
  void add(Pass *P) {
    schedulePass(P);
  }

  /// createPrinterPass - Get a function printer pass.
  Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const {
    return createPrintFunctionPass(Banner, &O);
  }

  // Prepare for running an on the fly pass, freeing memory if needed
  // from a previous run.
  void releaseMemoryOnTheFly();

  /// run - Execute all of the passes scheduled for execution.  Keep track of
  /// whether any of the passes modifies the module, and if so, return true.
  bool run(Function &F);

  /// doInitialization - Run all of the initializers for the function passes.
  ///
  bool doInitialization(Module &M);

  /// doFinalization - Run all of the finalizers for the function passes.
  ///
  bool doFinalization(Module &M);


  virtual PMDataManager *getAsPMDataManager() { return this; }
  virtual Pass *getAsPass() { return this; }
  virtual PassManagerType getTopLevelPassManagerType() {
    return PMT_FunctionPassManager;
  }

  /// Pass Manager itself does not invalidate any analysis info.
  void getAnalysisUsage(AnalysisUsage &Info) const {
    Info.setPreservesAll();
  }

  FPPassManager *getContainedManager(unsigned N) {
    assert(N < PassManagers.size() && "Pass number out of range!");
    FPPassManager *FP = static_cast<FPPassManager *>(PassManagers[N]);
    return FP;
  }
};

void FunctionPassManagerImpl::anchor() {}

char FunctionPassManagerImpl::ID = 0;

//===----------------------------------------------------------------------===//
// MPPassManager
//
/// MPPassManager manages ModulePasses and function pass managers.
/// It batches all Module passes and function pass managers together and
/// sequences them to process one module.
class MPPassManager : public Pass, public PMDataManager {
public:
  static char ID;
  explicit MPPassManager() :
    Pass(PT_PassManager, ID), PMDataManager() { }

  // Delete on the fly managers.
  virtual ~MPPassManager() {
    for (std::map<Pass *, FunctionPassManagerImpl *>::iterator
           I = OnTheFlyManagers.begin(), E = OnTheFlyManagers.end();
         I != E; ++I) {
      FunctionPassManagerImpl *FPP = I->second;
      delete FPP;
    }
  }

  /// createPrinterPass - Get a module printer pass.
  Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const {
    return createPrintModulePass(&O, false, Banner);
  }

  /// run - Execute all of the passes scheduled for execution.  Keep track of
  /// whether any of the passes modifies the module, and if so, return true.
  bool runOnModule(Module &M);

  using llvm::Pass::doInitialization;
  using llvm::Pass::doFinalization;

  /// doInitialization - Run all of the initializers for the module passes.
  ///
  bool doInitialization();

  /// doFinalization - Run all of the finalizers for the module passes.
  ///
  bool doFinalization();

  /// Pass Manager itself does not invalidate any analysis info.
  void getAnalysisUsage(AnalysisUsage &Info) const {
    Info.setPreservesAll();
  }

  /// Add RequiredPass into list of lower level passes required by pass P.
  /// RequiredPass is run on the fly by Pass Manager when P requests it
  /// through getAnalysis interface.
  virtual void addLowerLevelRequiredPass(Pass *P, Pass *RequiredPass);

  /// Return function pass corresponding to PassInfo PI, that is
  /// required by module pass MP. Instantiate analysis pass, by using
  /// its runOnFunction() for function F.
  virtual Pass* getOnTheFlyPass(Pass *MP, AnalysisID PI, Function &F);

  virtual const char *getPassName() const {
    return "Module Pass Manager";
  }

  virtual PMDataManager *getAsPMDataManager() { return this; }
  virtual Pass *getAsPass() { return this; }

  // Print passes managed by this manager
  void dumpPassStructure(unsigned Offset) {
    llvm::dbgs().indent(Offset*2) << "ModulePass Manager\n";
    for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
      ModulePass *MP = getContainedPass(Index);
      MP->dumpPassStructure(Offset + 1);
      std::map<Pass *, FunctionPassManagerImpl *>::const_iterator I =
        OnTheFlyManagers.find(MP);
      if (I != OnTheFlyManagers.end())
        I->second->dumpPassStructure(Offset + 2);
      dumpLastUses(MP, Offset+1);
    }
  }

  ModulePass *getContainedPass(unsigned N) {
    assert(N < PassVector.size() && "Pass number out of range!");
    return static_cast<ModulePass *>(PassVector[N]);
  }

  virtual PassManagerType getPassManagerType() const {
    return PMT_ModulePassManager;
  }

 private:
  /// Collection of on the fly FPPassManagers. These managers manage
  /// function passes that are required by module passes.
  std::map<Pass *, FunctionPassManagerImpl *> OnTheFlyManagers;
};

char MPPassManager::ID = 0;
//===----------------------------------------------------------------------===//
// PassManagerImpl
//

/// PassManagerImpl manages MPPassManagers
class PassManagerImpl : public Pass,
                        public PMDataManager,
                        public PMTopLevelManager {
  virtual void anchor();

public:
  static char ID;
  explicit PassManagerImpl() :
    Pass(PT_PassManager, ID), PMDataManager(),
                              PMTopLevelManager(new MPPassManager()) {}

  /// add - Add a pass to the queue of passes to run.  This passes ownership of
  /// the Pass to the PassManager.  When the PassManager is destroyed, the pass
  /// will be destroyed as well, so there is no need to delete the pass.  This
  /// implies that all passes MUST be allocated with 'new'.
  void add(Pass *P) {
    schedulePass(P);
  }

  /// createPrinterPass - Get a module printer pass.
  Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const {
    return createPrintModulePass(&O, false, Banner);
  }

  /// run - Execute all of the passes scheduled for execution.  Keep track of
  /// whether any of the passes modifies the module, and if so, return true.
  bool run(Module &M);

  using llvm::Pass::doInitialization;
  using llvm::Pass::doFinalization;

  /// doInitialization - Run all of the initializers for the module passes.
  ///
  bool doInitialization();

  /// doFinalization - Run all of the finalizers for the module passes.
  ///
  bool doFinalization();

  /// Pass Manager itself does not invalidate any analysis info.
  void getAnalysisUsage(AnalysisUsage &Info) const {
    Info.setPreservesAll();
  }

  virtual PMDataManager *getAsPMDataManager() { return this; }
  virtual Pass *getAsPass() { return this; }
  virtual PassManagerType getTopLevelPassManagerType() {
    return PMT_ModulePassManager;
  }

  MPPassManager *getContainedManager(unsigned N) {
    assert(N < PassManagers.size() && "Pass number out of range!");
    MPPassManager *MP = static_cast<MPPassManager *>(PassManagers[N]);
    return MP;
  }
};

void PassManagerImpl::anchor() {}

char PassManagerImpl::ID = 0;
} // End of llvm namespace

namespace {

//===----------------------------------------------------------------------===//
/// TimingInfo Class - This class is used to calculate information about the
/// amount of time each pass takes to execute.  This only happens when
/// -time-passes is enabled on the command line.
///

static ManagedStatic<sys::SmartMutex<true> > TimingInfoMutex;

class TimingInfo {
  DenseMap<Pass*, Timer*> TimingData;
  TimerGroup TG;
public:
  // Use 'create' member to get this.
  TimingInfo() : TG("... Pass execution timing report ...") {}

  // TimingDtor - Print out information about timing information
  ~TimingInfo() {
    // Delete all of the timers, which accumulate their info into the
    // TimerGroup.
    for (DenseMap<Pass*, Timer*>::iterator I = TimingData.begin(),
         E = TimingData.end(); I != E; ++I)
      delete I->second;
    // TimerGroup is deleted next, printing the report.
  }

  // createTheTimeInfo - This method either initializes the TheTimeInfo pointer
  // to a non null value (if the -time-passes option is enabled) or it leaves it
  // null.  It may be called multiple times.
  static void createTheTimeInfo();

  /// getPassTimer - Return the timer for the specified pass if it exists.
  Timer *getPassTimer(Pass *P) {
    if (P->getAsPMDataManager())
      return 0;

    sys::SmartScopedLock<true> Lock(*TimingInfoMutex);
    Timer *&T = TimingData[P];
    if (T == 0)
      T = new Timer(P->getPassName(), TG);
    return T;
  }
};

} // End of anon namespace

static TimingInfo *TheTimeInfo;

//===----------------------------------------------------------------------===//
// PMTopLevelManager implementation

/// Initialize top level manager. Create first pass manager.
PMTopLevelManager::PMTopLevelManager(PMDataManager *PMDM) {
  PMDM->setTopLevelManager(this);
  addPassManager(PMDM);
  activeStack.push(PMDM);
}

/// Set pass P as the last user of the given analysis passes.
void
PMTopLevelManager::setLastUser(ArrayRef<Pass*> AnalysisPasses, Pass *P) {
  unsigned PDepth = 0;
  if (P->getResolver())
    PDepth = P->getResolver()->getPMDataManager().getDepth();

  for (SmallVectorImpl<Pass *>::const_iterator I = AnalysisPasses.begin(),
         E = AnalysisPasses.end(); I != E; ++I) {
    Pass *AP = *I;
    LastUser[AP] = P;

    if (P == AP)
      continue;

    // Update the last users of passes that are required transitive by AP.
    AnalysisUsage *AnUsage = findAnalysisUsage(AP);
    const AnalysisUsage::VectorType &IDs = AnUsage->getRequiredTransitiveSet();
    SmallVector<Pass *, 12> LastUses;
    SmallVector<Pass *, 12> LastPMUses;
    for (AnalysisUsage::VectorType::const_iterator I = IDs.begin(),
         E = IDs.end(); I != E; ++I) {
      Pass *AnalysisPass = findAnalysisPass(*I);
      assert(AnalysisPass && "Expected analysis pass to exist.");
      AnalysisResolver *AR = AnalysisPass->getResolver();
      assert(AR && "Expected analysis resolver to exist.");
      unsigned APDepth = AR->getPMDataManager().getDepth();

      if (PDepth == APDepth)
        LastUses.push_back(AnalysisPass);
      else if (PDepth > APDepth)
        LastPMUses.push_back(AnalysisPass);
    }

    setLastUser(LastUses, P);

    // If this pass has a corresponding pass manager, push higher level
    // analysis to this pass manager.
    if (P->getResolver())
      setLastUser(LastPMUses, P->getResolver()->getPMDataManager().getAsPass());


    // If AP is the last user of other passes then make P last user of
    // such passes.
    for (DenseMap<Pass *, Pass *>::iterator LUI = LastUser.begin(),
           LUE = LastUser.end(); LUI != LUE; ++LUI) {
      if (LUI->second == AP)
        // DenseMap iterator is not invalidated here because
        // this is just updating existing entries.
        LastUser[LUI->first] = P;
    }
  }
}

/// Collect passes whose last user is P
void PMTopLevelManager::collectLastUses(SmallVectorImpl<Pass *> &LastUses,
                                        Pass *P) {
  DenseMap<Pass *, SmallPtrSet<Pass *, 8> >::iterator DMI =
    InversedLastUser.find(P);
  if (DMI == InversedLastUser.end())
    return;

  SmallPtrSet<Pass *, 8> &LU = DMI->second;
  for (SmallPtrSet<Pass *, 8>::iterator I = LU.begin(),
         E = LU.end(); I != E; ++I) {
    LastUses.push_back(*I);
  }

}

AnalysisUsage *PMTopLevelManager::findAnalysisUsage(Pass *P) {
  AnalysisUsage *AnUsage = NULL;
  DenseMap<Pass *, AnalysisUsage *>::iterator DMI = AnUsageMap.find(P);
  if (DMI != AnUsageMap.end())
    AnUsage = DMI->second;
  else {
    AnUsage = new AnalysisUsage();
    P->getAnalysisUsage(*AnUsage);
    AnUsageMap[P] = AnUsage;
  }
  return AnUsage;
}

/// Schedule pass P for execution. Make sure that passes required by
/// P are run before P is run. Update analysis info maintained by
/// the manager. Remove dead passes. This is a recursive function.
void PMTopLevelManager::schedulePass(Pass *P) {

  // TODO : Allocate function manager for this pass, other wise required set
  // may be inserted into previous function manager

  // Give pass a chance to prepare the stage.
  P->preparePassManager(activeStack);

  // If P is an analysis pass and it is available then do not
  // generate the analysis again. Stale analysis info should not be
  // available at this point.
  const PassInfo *PI =
    PassRegistry::getPassRegistry()->getPassInfo(P->getPassID());
  if (PI && PI->isAnalysis() && findAnalysisPass(P->getPassID())) {
    delete P;
    return;
  }

  AnalysisUsage *AnUsage = findAnalysisUsage(P);

  bool checkAnalysis = true;
  while (checkAnalysis) {
    checkAnalysis = false;

    const AnalysisUsage::VectorType &RequiredSet = AnUsage->getRequiredSet();
    for (AnalysisUsage::VectorType::const_iterator I = RequiredSet.begin(),
           E = RequiredSet.end(); I != E; ++I) {

      Pass *AnalysisPass = findAnalysisPass(*I);
      if (!AnalysisPass) {
        const PassInfo *PI = PassRegistry::getPassRegistry()->getPassInfo(*I);

        if (PI == NULL) {
          // Pass P is not in the global PassRegistry
          dbgs() << "Pass '"  << P->getPassName() << "' is not initialized." << "\n";
          dbgs() << "Verify if there is a pass dependency cycle." << "\n";
          dbgs() << "Required Passes:" << "\n";
          for (AnalysisUsage::VectorType::const_iterator I2 = RequiredSet.begin(),
                 E = RequiredSet.end(); I2 != E && I2 != I; ++I2) {
            Pass *AnalysisPass2 = findAnalysisPass(*I2);
            if (AnalysisPass2) {
              dbgs() << "\t" << AnalysisPass2->getPassName() << "\n";
            } else {
              dbgs() << "\t"   << "Error: Required pass not found! Possible causes:"  << "\n";
              dbgs() << "\t\t" << "- Pass misconfiguration (e.g.: missing macros)"    << "\n";
              dbgs() << "\t\t" << "- Corruption of the global PassRegistry"           << "\n";
            }
          }
        }

        assert(PI && "Expected required passes to be initialized");
        AnalysisPass = PI->createPass();
        if (P->getPotentialPassManagerType () ==
            AnalysisPass->getPotentialPassManagerType())
          // Schedule analysis pass that is managed by the same pass manager.
          schedulePass(AnalysisPass);
        else if (P->getPotentialPassManagerType () >
                 AnalysisPass->getPotentialPassManagerType()) {
          // Schedule analysis pass that is managed by a new manager.
          schedulePass(AnalysisPass);
          // Recheck analysis passes to ensure that required analyses that
          // are already checked are still available.
          checkAnalysis = true;
        } else
          // Do not schedule this analysis. Lower level analsyis
          // passes are run on the fly.
          delete AnalysisPass;
      }
    }
  }

  // Now all required passes are available.
  if (ImmutablePass *IP = P->getAsImmutablePass()) {
    // P is a immutable pass and it will be managed by this
    // top level manager. Set up analysis resolver to connect them.
    PMDataManager *DM = getAsPMDataManager();
    AnalysisResolver *AR = new AnalysisResolver(*DM);
    P->setResolver(AR);
    DM->initializeAnalysisImpl(P);
    addImmutablePass(IP);
    DM->recordAvailableAnalysis(IP);
    return;
  }

  if (PI && !PI->isAnalysis() && ShouldPrintBeforePass(PI)) {
    Pass *PP = P->createPrinterPass(
      dbgs(), std::string("*** IR Dump Before ") + P->getPassName() + " ***");
    PP->assignPassManager(activeStack, getTopLevelPassManagerType());
  }

  // Add the requested pass to the best available pass manager.
  P->assignPassManager(activeStack, getTopLevelPassManagerType());

  if (PI && !PI->isAnalysis() && ShouldPrintAfterPass(PI)) {
    Pass *PP = P->createPrinterPass(
      dbgs(), std::string("*** IR Dump After ") + P->getPassName() + " ***");
    PP->assignPassManager(activeStack, getTopLevelPassManagerType());
  }
}

/// Find the pass that implements Analysis AID. Search immutable
/// passes and all pass managers. If desired pass is not found
/// then return NULL.
Pass *PMTopLevelManager::findAnalysisPass(AnalysisID AID) {

  // Check pass managers
  for (SmallVectorImpl<PMDataManager *>::iterator I = PassManagers.begin(),
         E = PassManagers.end(); I != E; ++I)
    if (Pass *P = (*I)->findAnalysisPass(AID, false))
      return P;

  // Check other pass managers
  for (SmallVectorImpl<PMDataManager *>::iterator
         I = IndirectPassManagers.begin(),
         E = IndirectPassManagers.end(); I != E; ++I)
    if (Pass *P = (*I)->findAnalysisPass(AID, false))
      return P;

  // Check the immutable passes. Iterate in reverse order so that we find
  // the most recently registered passes first.
  for (SmallVector<ImmutablePass *, 8>::reverse_iterator I =
       ImmutablePasses.rbegin(), E = ImmutablePasses.rend(); I != E; ++I) {
    AnalysisID PI = (*I)->getPassID();
    if (PI == AID)
      return *I;

    // If Pass not found then check the interfaces implemented by Immutable Pass
    const PassInfo *PassInf =
      PassRegistry::getPassRegistry()->getPassInfo(PI);
    assert(PassInf && "Expected all immutable passes to be initialized");
    const std::vector<const PassInfo*> &ImmPI =
      PassInf->getInterfacesImplemented();
    for (std::vector<const PassInfo*>::const_iterator II = ImmPI.begin(),
         EE = ImmPI.end(); II != EE; ++II) {
      if ((*II)->getTypeInfo() == AID)
        return *I;
    }
  }

  return 0;
}

// Print passes managed by this top level manager.
void PMTopLevelManager::dumpPasses() const {

  if (PassDebugging < Structure)
    return;

  // Print out the immutable passes
  for (unsigned i = 0, e = ImmutablePasses.size(); i != e; ++i) {
    ImmutablePasses[i]->dumpPassStructure(0);
  }

  // Every class that derives from PMDataManager also derives from Pass
  // (sometimes indirectly), but there's no inheritance relationship
  // between PMDataManager and Pass, so we have to getAsPass to get
  // from a PMDataManager* to a Pass*.
  for (SmallVector<PMDataManager *, 8>::const_iterator I = PassManagers.begin(),
         E = PassManagers.end(); I != E; ++I)
    (*I)->getAsPass()->dumpPassStructure(1);
}

void PMTopLevelManager::dumpArguments() const {

  if (PassDebugging < Arguments)
    return;

  dbgs() << "Pass Arguments: ";
  for (SmallVector<ImmutablePass *, 8>::const_iterator I =
       ImmutablePasses.begin(), E = ImmutablePasses.end(); I != E; ++I)
    if (const PassInfo *PI =
        PassRegistry::getPassRegistry()->getPassInfo((*I)->getPassID())) {
      assert(PI && "Expected all immutable passes to be initialized");
      if (!PI->isAnalysisGroup())
        dbgs() << " -" << PI->getPassArgument();
    }
  for (SmallVector<PMDataManager *, 8>::const_iterator I = PassManagers.begin(),
         E = PassManagers.end(); I != E; ++I)
    (*I)->dumpPassArguments();
  dbgs() << "\n";
}

void PMTopLevelManager::initializeAllAnalysisInfo() {
  for (SmallVectorImpl<PMDataManager *>::iterator I = PassManagers.begin(),
         E = PassManagers.end(); I != E; ++I)
    (*I)->initializeAnalysisInfo();

  // Initailize other pass managers
  for (SmallVectorImpl<PMDataManager *>::iterator
       I = IndirectPassManagers.begin(), E = IndirectPassManagers.end();
       I != E; ++I)
    (*I)->initializeAnalysisInfo();

  for (DenseMap<Pass *, Pass *>::iterator DMI = LastUser.begin(),
        DME = LastUser.end(); DMI != DME; ++DMI) {
    DenseMap<Pass *, SmallPtrSet<Pass *, 8> >::iterator InvDMI =
      InversedLastUser.find(DMI->second);
    if (InvDMI != InversedLastUser.end()) {
      SmallPtrSet<Pass *, 8> &L = InvDMI->second;
      L.insert(DMI->first);
    } else {
      SmallPtrSet<Pass *, 8> L; L.insert(DMI->first);
      InversedLastUser[DMI->second] = L;
    }
  }
}

/// Destructor
PMTopLevelManager::~PMTopLevelManager() {
  for (SmallVectorImpl<PMDataManager *>::iterator I = PassManagers.begin(),
         E = PassManagers.end(); I != E; ++I)
    delete *I;

  for (SmallVectorImpl<ImmutablePass *>::iterator
         I = ImmutablePasses.begin(), E = ImmutablePasses.end(); I != E; ++I)
    delete *I;

  for (DenseMap<Pass *, AnalysisUsage *>::iterator DMI = AnUsageMap.begin(),
         DME = AnUsageMap.end(); DMI != DME; ++DMI)
    delete DMI->second;
}

//===----------------------------------------------------------------------===//
// PMDataManager implementation

/// Augement AvailableAnalysis by adding analysis made available by pass P.
void PMDataManager::recordAvailableAnalysis(Pass *P) {
  AnalysisID PI = P->getPassID();

  AvailableAnalysis[PI] = P;

  assert(!AvailableAnalysis.empty());

  // This pass is the current implementation of all of the interfaces it
  // implements as well.
  const PassInfo *PInf = PassRegistry::getPassRegistry()->getPassInfo(PI);
  if (PInf == 0) return;
  const std::vector<const PassInfo*> &II = PInf->getInterfacesImplemented();
  for (unsigned i = 0, e = II.size(); i != e; ++i)
    AvailableAnalysis[II[i]->getTypeInfo()] = P;
}

// Return true if P preserves high level analysis used by other
// passes managed by this manager
bool PMDataManager::preserveHigherLevelAnalysis(Pass *P) {
  AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
  if (AnUsage->getPreservesAll())
    return true;

  const AnalysisUsage::VectorType &PreservedSet = AnUsage->getPreservedSet();
  for (SmallVectorImpl<Pass *>::iterator I = HigherLevelAnalysis.begin(),
         E = HigherLevelAnalysis.end(); I  != E; ++I) {
    Pass *P1 = *I;
    if (P1->getAsImmutablePass() == 0 &&
        std::find(PreservedSet.begin(), PreservedSet.end(),
                  P1->getPassID()) ==
           PreservedSet.end())
      return false;
  }

  return true;
}

/// verifyPreservedAnalysis -- Verify analysis preserved by pass P.
void PMDataManager::verifyPreservedAnalysis(Pass *P) {
  // Don't do this unless assertions are enabled.
#ifdef NDEBUG
  return;
#endif
  AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
  const AnalysisUsage::VectorType &PreservedSet = AnUsage->getPreservedSet();

  // Verify preserved analysis
  for (AnalysisUsage::VectorType::const_iterator I = PreservedSet.begin(),
         E = PreservedSet.end(); I != E; ++I) {
    AnalysisID AID = *I;
    if (Pass *AP = findAnalysisPass(AID, true)) {
      TimeRegion PassTimer(getPassTimer(AP));
      AP->verifyAnalysis();
    }
  }
}

/// Remove Analysis not preserved by Pass P
void PMDataManager::removeNotPreservedAnalysis(Pass *P) {
  AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
  if (AnUsage->getPreservesAll())
    return;

  const AnalysisUsage::VectorType &PreservedSet = AnUsage->getPreservedSet();
  for (std::map<AnalysisID, Pass*>::iterator I = AvailableAnalysis.begin(),
         E = AvailableAnalysis.end(); I != E; ) {
    std::map<AnalysisID, Pass*>::iterator Info = I++;
    if (Info->second->getAsImmutablePass() == 0 &&
        std::find(PreservedSet.begin(), PreservedSet.end(), Info->first) ==
        PreservedSet.end()) {
      // Remove this analysis
      if (PassDebugging >= Details) {
        Pass *S = Info->second;
        dbgs() << " -- '" <<  P->getPassName() << "' is not preserving '";
        dbgs() << S->getPassName() << "'\n";
      }
      AvailableAnalysis.erase(Info);
    }
  }

  // Check inherited analysis also. If P is not preserving analysis
  // provided by parent manager then remove it here.
  for (unsigned Index = 0; Index < PMT_Last; ++Index) {

    if (!InheritedAnalysis[Index])
      continue;

    for (std::map<AnalysisID, Pass*>::iterator
           I = InheritedAnalysis[Index]->begin(),
           E = InheritedAnalysis[Index]->end(); I != E; ) {
      std::map<AnalysisID, Pass *>::iterator Info = I++;
      if (Info->second->getAsImmutablePass() == 0 &&
          std::find(PreservedSet.begin(), PreservedSet.end(), Info->first) ==
             PreservedSet.end()) {
        // Remove this analysis
        if (PassDebugging >= Details) {
          Pass *S = Info->second;
          dbgs() << " -- '" <<  P->getPassName() << "' is not preserving '";
          dbgs() << S->getPassName() << "'\n";
        }
        InheritedAnalysis[Index]->erase(Info);
      }
    }
  }
}

/// Remove analysis passes that are not used any longer
void PMDataManager::removeDeadPasses(Pass *P, StringRef Msg,
                                     enum PassDebuggingString DBG_STR) {

  SmallVector<Pass *, 12> DeadPasses;

  // If this is a on the fly manager then it does not have TPM.
  if (!TPM)
    return;

  TPM->collectLastUses(DeadPasses, P);

  if (PassDebugging >= Details && !DeadPasses.empty()) {
    dbgs() << " -*- '" <<  P->getPassName();
    dbgs() << "' is the last user of following pass instances.";
    dbgs() << " Free these instances\n";
  }

  for (SmallVectorImpl<Pass *>::iterator I = DeadPasses.begin(),
         E = DeadPasses.end(); I != E; ++I)
    freePass(*I, Msg, DBG_STR);
}

void PMDataManager::freePass(Pass *P, StringRef Msg,
                             enum PassDebuggingString DBG_STR) {
  dumpPassInfo(P, FREEING_MSG, DBG_STR, Msg);

  {
    // If the pass crashes releasing memory, remember this.
    PassManagerPrettyStackEntry X(P);
    TimeRegion PassTimer(getPassTimer(P));

    P->releaseMemory();
  }

  AnalysisID PI = P->getPassID();
  if (const PassInfo *PInf = PassRegistry::getPassRegistry()->getPassInfo(PI)) {
    // Remove the pass itself (if it is not already removed).
    AvailableAnalysis.erase(PI);

    // Remove all interfaces this pass implements, for which it is also
    // listed as the available implementation.
    const std::vector<const PassInfo*> &II = PInf->getInterfacesImplemented();
    for (unsigned i = 0, e = II.size(); i != e; ++i) {
      std::map<AnalysisID, Pass*>::iterator Pos =
        AvailableAnalysis.find(II[i]->getTypeInfo());
      if (Pos != AvailableAnalysis.end() && Pos->second == P)
        AvailableAnalysis.erase(Pos);
    }
  }
}

/// Add pass P into the PassVector. Update
/// AvailableAnalysis appropriately if ProcessAnalysis is true.
void PMDataManager::add(Pass *P, bool ProcessAnalysis) {
  // This manager is going to manage pass P. Set up analysis resolver
  // to connect them.
  AnalysisResolver *AR = new AnalysisResolver(*this);
  P->setResolver(AR);

  // If a FunctionPass F is the last user of ModulePass info M
  // then the F's manager, not F, records itself as a last user of M.
  SmallVector<Pass *, 12> TransferLastUses;

  if (!ProcessAnalysis) {
    // Add pass
    PassVector.push_back(P);
    return;
  }

  // At the moment, this pass is the last user of all required passes.
  SmallVector<Pass *, 12> LastUses;
  SmallVector<Pass *, 8> RequiredPasses;
  SmallVector<AnalysisID, 8> ReqAnalysisNotAvailable;

  unsigned PDepth = this->getDepth();

  collectRequiredAnalysis(RequiredPasses,
                          ReqAnalysisNotAvailable, P);
  for (SmallVectorImpl<Pass *>::iterator I = RequiredPasses.begin(),
         E = RequiredPasses.end(); I != E; ++I) {
    Pass *PRequired = *I;