Home | History | Annotate | Download | only in VMCore
      1 //===- PassManager.cpp - LLVM Pass Infrastructure Implementation ----------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file implements the LLVM Pass Manager infrastructure.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 
     15 #include "llvm/PassManagers.h"
     16 #include "llvm/PassManager.h"
     17 #include "llvm/Assembly/PrintModulePass.h"
     18 #include "llvm/Assembly/Writer.h"
     19 #include "llvm/Support/CommandLine.h"
     20 #include "llvm/Support/Debug.h"
     21 #include "llvm/Support/Timer.h"
     22 #include "llvm/Module.h"
     23 #include "llvm/Support/ErrorHandling.h"
     24 #include "llvm/Support/ManagedStatic.h"
     25 #include "llvm/Support/PassNameParser.h"
     26 #include "llvm/Support/raw_ostream.h"
     27 #include "llvm/Support/Mutex.h"
     28 #include <algorithm>
     29 #include <map>
     30 using namespace llvm;
     31 
     32 // See PassManagers.h for Pass Manager infrastructure overview.
     33 
     34 namespace llvm {
     35 
     36 //===----------------------------------------------------------------------===//
     37 // Pass debugging information.  Often it is useful to find out what pass is
     38 // running when a crash occurs in a utility.  When this library is compiled with
     39 // debugging on, a command line option (--debug-pass) is enabled that causes the
     40 // pass name to be printed before it executes.
     41 //
     42 
     43 // Different debug levels that can be enabled...
     44 enum PassDebugLevel {
     45   None, Arguments, Structure, Executions, Details
     46 };
     47 
     48 static cl::opt<enum PassDebugLevel>
     49 PassDebugging("debug-pass", cl::Hidden,
     50                   cl::desc("Print PassManager debugging information"),
     51                   cl::values(
     52   clEnumVal(None      , "disable debug output"),
     53   clEnumVal(Arguments , "print pass arguments to pass to 'opt'"),
     54   clEnumVal(Structure , "print pass structure before run()"),
     55   clEnumVal(Executions, "print pass name before it is executed"),
     56   clEnumVal(Details   , "print pass details when it is executed"),
     57                              clEnumValEnd));
     58 
     59 typedef llvm::cl::list<const llvm::PassInfo *, bool, PassNameParser>
     60 PassOptionList;
     61 
     62 // Print IR out before/after specified passes.
     63 static PassOptionList
     64 PrintBefore("print-before",
     65             llvm::cl::desc("Print IR before specified passes"),
     66             cl::Hidden);
     67 
     68 static PassOptionList
     69 PrintAfter("print-after",
     70            llvm::cl::desc("Print IR after specified passes"),
     71            cl::Hidden);
     72 
     73 static cl::opt<bool>
     74 PrintBeforeAll("print-before-all",
     75                llvm::cl::desc("Print IR before each pass"),
     76                cl::init(false));
     77 static cl::opt<bool>
     78 PrintAfterAll("print-after-all",
     79               llvm::cl::desc("Print IR after each pass"),
     80               cl::init(false));
     81 
     82 /// This is a helper to determine whether to print IR before or
     83 /// after a pass.
     84 
     85 static bool ShouldPrintBeforeOrAfterPass(const PassInfo *PI,
     86                                          PassOptionList &PassesToPrint) {
     87   for (unsigned i = 0, ie = PassesToPrint.size(); i < ie; ++i) {
     88     const llvm::PassInfo *PassInf = PassesToPrint[i];
     89     if (PassInf)
     90       if (PassInf->getPassArgument() == PI->getPassArgument()) {
     91         return true;
     92       }
     93   }
     94   return false;
     95 }
     96 
     97 /// This is a utility to check whether a pass should have IR dumped
     98 /// before it.
     99 static bool ShouldPrintBeforePass(const PassInfo *PI) {
    100   return PrintBeforeAll || ShouldPrintBeforeOrAfterPass(PI, PrintBefore);
    101 }
    102 
    103 /// This is a utility to check whether a pass should have IR dumped
    104 /// after it.
    105 static bool ShouldPrintAfterPass(const PassInfo *PI) {
    106   return PrintAfterAll || ShouldPrintBeforeOrAfterPass(PI, PrintAfter);
    107 }
    108 
    109 } // End of llvm namespace
    110 
    111 /// isPassDebuggingExecutionsOrMore - Return true if -debug-pass=Executions
    112 /// or higher is specified.
    113 bool PMDataManager::isPassDebuggingExecutionsOrMore() const {
    114   return PassDebugging >= Executions;
    115 }
    116 
    117 
    118 
    119 
    120 void PassManagerPrettyStackEntry::print(raw_ostream &OS) const {
    121   if (V == 0 && M == 0)
    122     OS << "Releasing pass '";
    123   else
    124     OS << "Running pass '";
    125 
    126   OS << P->getPassName() << "'";
    127 
    128   if (M) {
    129     OS << " on module '" << M->getModuleIdentifier() << "'.\n";
    130     return;
    131   }
    132   if (V == 0) {
    133     OS << '\n';
    134     return;
    135   }
    136 
    137   OS << " on ";
    138   if (isa<Function>(V))
    139     OS << "function";
    140   else if (isa<BasicBlock>(V))
    141     OS << "basic block";
    142   else
    143     OS << "value";
    144 
    145   OS << " '";
    146   WriteAsOperand(OS, V, /*PrintTy=*/false, M);
    147   OS << "'\n";
    148 }
    149 
    150 
    151 namespace {
    152 
    153 //===----------------------------------------------------------------------===//
    154 // BBPassManager
    155 //
    156 /// BBPassManager manages BasicBlockPass. It batches all the
    157 /// pass together and sequence them to process one basic block before
    158 /// processing next basic block.
    159 class BBPassManager : public PMDataManager, public FunctionPass {
    160 
    161 public:
    162   static char ID;
    163   explicit BBPassManager()
    164     : PMDataManager(), FunctionPass(ID) {}
    165 
    166   /// Execute all of the passes scheduled for execution.  Keep track of
    167   /// whether any of the passes modifies the function, and if so, return true.
    168   bool runOnFunction(Function &F);
    169 
    170   /// Pass Manager itself does not invalidate any analysis info.
    171   void getAnalysisUsage(AnalysisUsage &Info) const {
    172     Info.setPreservesAll();
    173   }
    174 
    175   bool doInitialization(Module &M);
    176   bool doInitialization(Function &F);
    177   bool doFinalization(Module &M);
    178   bool doFinalization(Function &F);
    179 
    180   virtual PMDataManager *getAsPMDataManager() { return this; }
    181   virtual Pass *getAsPass() { return this; }
    182 
    183   virtual const char *getPassName() const {
    184     return "BasicBlock Pass Manager";
    185   }
    186 
    187   // Print passes managed by this manager
    188   void dumpPassStructure(unsigned Offset) {
    189     llvm::dbgs().indent(Offset*2) << "BasicBlockPass Manager\n";
    190     for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
    191       BasicBlockPass *BP = getContainedPass(Index);
    192       BP->dumpPassStructure(Offset + 1);
    193       dumpLastUses(BP, Offset+1);
    194     }
    195   }
    196 
    197   BasicBlockPass *getContainedPass(unsigned N) {
    198     assert(N < PassVector.size() && "Pass number out of range!");
    199     BasicBlockPass *BP = static_cast<BasicBlockPass *>(PassVector[N]);
    200     return BP;
    201   }
    202 
    203   virtual PassManagerType getPassManagerType() const {
    204     return PMT_BasicBlockPassManager;
    205   }
    206 };
    207 
    208 char BBPassManager::ID = 0;
    209 }
    210 
    211 namespace llvm {
    212 
    213 //===----------------------------------------------------------------------===//
    214 // FunctionPassManagerImpl
    215 //
    216 /// FunctionPassManagerImpl manages FPPassManagers
    217 class FunctionPassManagerImpl : public Pass,
    218                                 public PMDataManager,
    219                                 public PMTopLevelManager {
    220   virtual void anchor();
    221 private:
    222   bool wasRun;
    223 public:
    224   static char ID;
    225   explicit FunctionPassManagerImpl() :
    226     Pass(PT_PassManager, ID), PMDataManager(),
    227     PMTopLevelManager(new FPPassManager()), wasRun(false) {}
    228 
    229   /// add - Add a pass to the queue of passes to run.  This passes ownership of
    230   /// the Pass to the PassManager.  When the PassManager is destroyed, the pass
    231   /// will be destroyed as well, so there is no need to delete the pass.  This
    232   /// implies that all passes MUST be allocated with 'new'.
    233   void add(Pass *P) {
    234     schedulePass(P);
    235   }
    236 
    237   /// createPrinterPass - Get a function printer pass.
    238   Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const {
    239     return createPrintFunctionPass(Banner, &O);
    240   }
    241 
    242   // Prepare for running an on the fly pass, freeing memory if needed
    243   // from a previous run.
    244   void releaseMemoryOnTheFly();
    245 
    246   /// run - Execute all of the passes scheduled for execution.  Keep track of
    247   /// whether any of the passes modifies the module, and if so, return true.
    248   bool run(Function &F);
    249 
    250   /// doInitialization - Run all of the initializers for the function passes.
    251   ///
    252   bool doInitialization(Module &M);
    253 
    254   /// doFinalization - Run all of the finalizers for the function passes.
    255   ///
    256   bool doFinalization(Module &M);
    257 
    258 
    259   virtual PMDataManager *getAsPMDataManager() { return this; }
    260   virtual Pass *getAsPass() { return this; }
    261   virtual PassManagerType getTopLevelPassManagerType() {
    262     return PMT_FunctionPassManager;
    263   }
    264 
    265   /// Pass Manager itself does not invalidate any analysis info.
    266   void getAnalysisUsage(AnalysisUsage &Info) const {
    267     Info.setPreservesAll();
    268   }
    269 
    270   FPPassManager *getContainedManager(unsigned N) {
    271     assert(N < PassManagers.size() && "Pass number out of range!");
    272     FPPassManager *FP = static_cast<FPPassManager *>(PassManagers[N]);
    273     return FP;
    274   }
    275 };
    276 
    277 void FunctionPassManagerImpl::anchor() {}
    278 
    279 char FunctionPassManagerImpl::ID = 0;
    280 
    281 //===----------------------------------------------------------------------===//
    282 // MPPassManager
    283 //
    284 /// MPPassManager manages ModulePasses and function pass managers.
    285 /// It batches all Module passes and function pass managers together and
    286 /// sequences them to process one module.
    287 class MPPassManager : public Pass, public PMDataManager {
    288 public:
    289   static char ID;
    290   explicit MPPassManager() :
    291     Pass(PT_PassManager, ID), PMDataManager() { }
    292 
    293   // Delete on the fly managers.
    294   virtual ~MPPassManager() {
    295     for (std::map<Pass *, FunctionPassManagerImpl *>::iterator
    296            I = OnTheFlyManagers.begin(), E = OnTheFlyManagers.end();
    297          I != E; ++I) {
    298       FunctionPassManagerImpl *FPP = I->second;
    299       delete FPP;
    300     }
    301   }
    302 
    303   /// createPrinterPass - Get a module printer pass.
    304   Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const {
    305     return createPrintModulePass(&O, false, Banner);
    306   }
    307 
    308   /// run - Execute all of the passes scheduled for execution.  Keep track of
    309   /// whether any of the passes modifies the module, and if so, return true.
    310   bool runOnModule(Module &M);
    311 
    312   /// Pass Manager itself does not invalidate any analysis info.
    313   void getAnalysisUsage(AnalysisUsage &Info) const {
    314     Info.setPreservesAll();
    315   }
    316 
    317   /// Add RequiredPass into list of lower level passes required by pass P.
    318   /// RequiredPass is run on the fly by Pass Manager when P requests it
    319   /// through getAnalysis interface.
    320   virtual void addLowerLevelRequiredPass(Pass *P, Pass *RequiredPass);
    321 
    322   /// Return function pass corresponding to PassInfo PI, that is
    323   /// required by module pass MP. Instantiate analysis pass, by using
    324   /// its runOnFunction() for function F.
    325   virtual Pass* getOnTheFlyPass(Pass *MP, AnalysisID PI, Function &F);
    326 
    327   virtual const char *getPassName() const {
    328     return "Module Pass Manager";
    329   }
    330 
    331   virtual PMDataManager *getAsPMDataManager() { return this; }
    332   virtual Pass *getAsPass() { return this; }
    333 
    334   // Print passes managed by this manager
    335   void dumpPassStructure(unsigned Offset) {
    336     llvm::dbgs().indent(Offset*2) << "ModulePass Manager\n";
    337     for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
    338       ModulePass *MP = getContainedPass(Index);
    339       MP->dumpPassStructure(Offset + 1);
    340       std::map<Pass *, FunctionPassManagerImpl *>::const_iterator I =
    341         OnTheFlyManagers.find(MP);
    342       if (I != OnTheFlyManagers.end())
    343         I->second->dumpPassStructure(Offset + 2);
    344       dumpLastUses(MP, Offset+1);
    345     }
    346   }
    347 
    348   ModulePass *getContainedPass(unsigned N) {
    349     assert(N < PassVector.size() && "Pass number out of range!");
    350     return static_cast<ModulePass *>(PassVector[N]);
    351   }
    352 
    353   virtual PassManagerType getPassManagerType() const {
    354     return PMT_ModulePassManager;
    355   }
    356 
    357  private:
    358   /// Collection of on the fly FPPassManagers. These managers manage
    359   /// function passes that are required by module passes.
    360   std::map<Pass *, FunctionPassManagerImpl *> OnTheFlyManagers;
    361 };
    362 
    363 char MPPassManager::ID = 0;
    364 //===----------------------------------------------------------------------===//
    365 // PassManagerImpl
    366 //
    367 
    368 /// PassManagerImpl manages MPPassManagers
    369 class PassManagerImpl : public Pass,
    370                         public PMDataManager,
    371                         public PMTopLevelManager {
    372   virtual void anchor();
    373 
    374 public:
    375   static char ID;
    376   explicit PassManagerImpl() :
    377     Pass(PT_PassManager, ID), PMDataManager(),
    378                               PMTopLevelManager(new MPPassManager()) {}
    379 
    380   /// add - Add a pass to the queue of passes to run.  This passes ownership of
    381   /// the Pass to the PassManager.  When the PassManager is destroyed, the pass
    382   /// will be destroyed as well, so there is no need to delete the pass.  This
    383   /// implies that all passes MUST be allocated with 'new'.
    384   void add(Pass *P) {
    385     schedulePass(P);
    386   }
    387 
    388   /// createPrinterPass - Get a module printer pass.
    389   Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const {
    390     return createPrintModulePass(&O, false, Banner);
    391   }
    392 
    393   /// run - Execute all of the passes scheduled for execution.  Keep track of
    394   /// whether any of the passes modifies the module, and if so, return true.
    395   bool run(Module &M);
    396 
    397   /// Pass Manager itself does not invalidate any analysis info.
    398   void getAnalysisUsage(AnalysisUsage &Info) const {
    399     Info.setPreservesAll();
    400   }
    401 
    402   virtual PMDataManager *getAsPMDataManager() { return this; }
    403   virtual Pass *getAsPass() { return this; }
    404   virtual PassManagerType getTopLevelPassManagerType() {
    405     return PMT_ModulePassManager;
    406   }
    407 
    408   MPPassManager *getContainedManager(unsigned N) {
    409     assert(N < PassManagers.size() && "Pass number out of range!");
    410     MPPassManager *MP = static_cast<MPPassManager *>(PassManagers[N]);
    411     return MP;
    412   }
    413 };
    414 
    415 void PassManagerImpl::anchor() {}
    416 
    417 char PassManagerImpl::ID = 0;
    418 } // End of llvm namespace
    419 
    420 namespace {
    421 
    422 //===----------------------------------------------------------------------===//
    423 /// TimingInfo Class - This class is used to calculate information about the
    424 /// amount of time each pass takes to execute.  This only happens when
    425 /// -time-passes is enabled on the command line.
    426 ///
    427 
    428 static ManagedStatic<sys::SmartMutex<true> > TimingInfoMutex;
    429 
    430 class TimingInfo {
    431   DenseMap<Pass*, Timer*> TimingData;
    432   TimerGroup TG;
    433 public:
    434   // Use 'create' member to get this.
    435   TimingInfo() : TG("... Pass execution timing report ...") {}
    436 
    437   // TimingDtor - Print out information about timing information
    438   ~TimingInfo() {
    439     // Delete all of the timers, which accumulate their info into the
    440     // TimerGroup.
    441     for (DenseMap<Pass*, Timer*>::iterator I = TimingData.begin(),
    442          E = TimingData.end(); I != E; ++I)
    443       delete I->second;
    444     // TimerGroup is deleted next, printing the report.
    445   }
    446 
    447   // createTheTimeInfo - This method either initializes the TheTimeInfo pointer
    448   // to a non null value (if the -time-passes option is enabled) or it leaves it
    449   // null.  It may be called multiple times.
    450   static void createTheTimeInfo();
    451 
    452   /// getPassTimer - Return the timer for the specified pass if it exists.
    453   Timer *getPassTimer(Pass *P) {
    454     if (P->getAsPMDataManager())
    455       return 0;
    456 
    457     sys::SmartScopedLock<true> Lock(*TimingInfoMutex);
    458     Timer *&T = TimingData[P];
    459     if (T == 0)
    460       T = new Timer(P->getPassName(), TG);
    461     return T;
    462   }
    463 };
    464 
    465 } // End of anon namespace
    466 
    467 static TimingInfo *TheTimeInfo;
    468 
    469 //===----------------------------------------------------------------------===//
    470 // PMTopLevelManager implementation
    471 
    472 /// Initialize top level manager. Create first pass manager.
    473 PMTopLevelManager::PMTopLevelManager(PMDataManager *PMDM) {
    474   PMDM->setTopLevelManager(this);
    475   addPassManager(PMDM);
    476   activeStack.push(PMDM);
    477 }
    478 
    479 /// Set pass P as the last user of the given analysis passes.
    480 void
    481 PMTopLevelManager::setLastUser(const SmallVectorImpl<Pass *> &AnalysisPasses,
    482                                Pass *P) {
    483   unsigned PDepth = 0;
    484   if (P->getResolver())
    485     PDepth = P->getResolver()->getPMDataManager().getDepth();
    486 
    487   for (SmallVectorImpl<Pass *>::const_iterator I = AnalysisPasses.begin(),
    488          E = AnalysisPasses.end(); I != E; ++I) {
    489     Pass *AP = *I;
    490     LastUser[AP] = P;
    491 
    492     if (P == AP)
    493       continue;
    494 
    495     // Update the last users of passes that are required transitive by AP.
    496     AnalysisUsage *AnUsage = findAnalysisUsage(AP);
    497     const AnalysisUsage::VectorType &IDs = AnUsage->getRequiredTransitiveSet();
    498     SmallVector<Pass *, 12> LastUses;
    499     SmallVector<Pass *, 12> LastPMUses;
    500     for (AnalysisUsage::VectorType::const_iterator I = IDs.begin(),
    501          E = IDs.end(); I != E; ++I) {
    502       Pass *AnalysisPass = findAnalysisPass(*I);
    503       assert(AnalysisPass && "Expected analysis pass to exist.");
    504       AnalysisResolver *AR = AnalysisPass->getResolver();
    505       assert(AR && "Expected analysis resolver to exist.");
    506       unsigned APDepth = AR->getPMDataManager().getDepth();
    507 
    508       if (PDepth == APDepth)
    509         LastUses.push_back(AnalysisPass);
    510       else if (PDepth > APDepth)
    511         LastPMUses.push_back(AnalysisPass);
    512     }
    513 
    514     setLastUser(LastUses, P);
    515 
    516     // If this pass has a corresponding pass manager, push higher level
    517     // analysis to this pass manager.
    518     if (P->getResolver())
    519       setLastUser(LastPMUses, P->getResolver()->getPMDataManager().getAsPass());
    520 
    521 
    522     // If AP is the last user of other passes then make P last user of
    523     // such passes.
    524     for (DenseMap<Pass *, Pass *>::iterator LUI = LastUser.begin(),
    525            LUE = LastUser.end(); LUI != LUE; ++LUI) {
    526       if (LUI->second == AP)
    527         // DenseMap iterator is not invalidated here because
    528         // this is just updating existing entries.
    529         LastUser[LUI->first] = P;
    530     }
    531   }
    532 }
    533 
    534 /// Collect passes whose last user is P
    535 void PMTopLevelManager::collectLastUses(SmallVectorImpl<Pass *> &LastUses,
    536                                         Pass *P) {
    537   DenseMap<Pass *, SmallPtrSet<Pass *, 8> >::iterator DMI =
    538     InversedLastUser.find(P);
    539   if (DMI == InversedLastUser.end())
    540     return;
    541 
    542   SmallPtrSet<Pass *, 8> &LU = DMI->second;
    543   for (SmallPtrSet<Pass *, 8>::iterator I = LU.begin(),
    544          E = LU.end(); I != E; ++I) {
    545     LastUses.push_back(*I);
    546   }
    547 
    548 }
    549 
    550 AnalysisUsage *PMTopLevelManager::findAnalysisUsage(Pass *P) {
    551   AnalysisUsage *AnUsage = NULL;
    552   DenseMap<Pass *, AnalysisUsage *>::iterator DMI = AnUsageMap.find(P);
    553   if (DMI != AnUsageMap.end())
    554     AnUsage = DMI->second;
    555   else {
    556     AnUsage = new AnalysisUsage();
    557     P->getAnalysisUsage(*AnUsage);
    558     AnUsageMap[P] = AnUsage;
    559   }
    560   return AnUsage;
    561 }
    562 
    563 /// Schedule pass P for execution. Make sure that passes required by
    564 /// P are run before P is run. Update analysis info maintained by
    565 /// the manager. Remove dead passes. This is a recursive function.
    566 void PMTopLevelManager::schedulePass(Pass *P) {
    567 
    568   // TODO : Allocate function manager for this pass, other wise required set
    569   // may be inserted into previous function manager
    570 
    571   // Give pass a chance to prepare the stage.
    572   P->preparePassManager(activeStack);
    573 
    574   // If P is an analysis pass and it is available then do not
    575   // generate the analysis again. Stale analysis info should not be
    576   // available at this point.
    577   const PassInfo *PI =
    578     PassRegistry::getPassRegistry()->getPassInfo(P->getPassID());
    579   if (PI && PI->isAnalysis() && findAnalysisPass(P->getPassID())) {
    580     delete P;
    581     return;
    582   }
    583 
    584   AnalysisUsage *AnUsage = findAnalysisUsage(P);
    585 
    586   bool checkAnalysis = true;
    587   while (checkAnalysis) {
    588     checkAnalysis = false;
    589 
    590     const AnalysisUsage::VectorType &RequiredSet = AnUsage->getRequiredSet();
    591     for (AnalysisUsage::VectorType::const_iterator I = RequiredSet.begin(),
    592            E = RequiredSet.end(); I != E; ++I) {
    593 
    594       Pass *AnalysisPass = findAnalysisPass(*I);
    595       if (!AnalysisPass) {
    596         const PassInfo *PI = PassRegistry::getPassRegistry()->getPassInfo(*I);
    597         assert(PI && "Expected required passes to be initialized");
    598         AnalysisPass = PI->createPass();
    599         if (P->getPotentialPassManagerType () ==
    600             AnalysisPass->getPotentialPassManagerType())
    601           // Schedule analysis pass that is managed by the same pass manager.
    602           schedulePass(AnalysisPass);
    603         else if (P->getPotentialPassManagerType () >
    604                  AnalysisPass->getPotentialPassManagerType()) {
    605           // Schedule analysis pass that is managed by a new manager.
    606           schedulePass(AnalysisPass);
    607           // Recheck analysis passes to ensure that required analyses that
    608           // are already checked are still available.
    609           checkAnalysis = true;
    610         }
    611         else
    612           // Do not schedule this analysis. Lower level analsyis
    613           // passes are run on the fly.
    614           delete AnalysisPass;
    615       }
    616     }
    617   }
    618 
    619   // Now all required passes are available.
    620   if (ImmutablePass *IP = P->getAsImmutablePass()) {
    621     // P is a immutable pass and it will be managed by this
    622     // top level manager. Set up analysis resolver to connect them.
    623     PMDataManager *DM = getAsPMDataManager();
    624     AnalysisResolver *AR = new AnalysisResolver(*DM);
    625     P->setResolver(AR);
    626     DM->initializeAnalysisImpl(P);
    627     addImmutablePass(IP);
    628     DM->recordAvailableAnalysis(IP);
    629     return;
    630   }
    631 
    632   if (PI && !PI->isAnalysis() && ShouldPrintBeforePass(PI)) {
    633     Pass *PP = P->createPrinterPass(
    634       dbgs(), std::string("*** IR Dump Before ") + P->getPassName() + " ***");
    635     PP->assignPassManager(activeStack, getTopLevelPassManagerType());
    636   }
    637 
    638   // Add the requested pass to the best available pass manager.
    639   P->assignPassManager(activeStack, getTopLevelPassManagerType());
    640 
    641   if (PI && !PI->isAnalysis() && ShouldPrintAfterPass(PI)) {
    642     Pass *PP = P->createPrinterPass(
    643       dbgs(), std::string("*** IR Dump After ") + P->getPassName() + " ***");
    644     PP->assignPassManager(activeStack, getTopLevelPassManagerType());
    645   }
    646 }
    647 
    648 /// Find the pass that implements Analysis AID. Search immutable
    649 /// passes and all pass managers. If desired pass is not found
    650 /// then return NULL.
    651 Pass *PMTopLevelManager::findAnalysisPass(AnalysisID AID) {
    652 
    653   // Check pass managers
    654   for (SmallVectorImpl<PMDataManager *>::iterator I = PassManagers.begin(),
    655          E = PassManagers.end(); I != E; ++I)
    656     if (Pass *P = (*I)->findAnalysisPass(AID, false))
    657       return P;
    658 
    659   // Check other pass managers
    660   for (SmallVectorImpl<PMDataManager *>::iterator
    661          I = IndirectPassManagers.begin(),
    662          E = IndirectPassManagers.end(); I != E; ++I)
    663     if (Pass *P = (*I)->findAnalysisPass(AID, false))
    664       return P;
    665 
    666   // Check the immutable passes. Iterate in reverse order so that we find
    667   // the most recently registered passes first.
    668   for (SmallVector<ImmutablePass *, 8>::reverse_iterator I =
    669        ImmutablePasses.rbegin(), E = ImmutablePasses.rend(); I != E; ++I) {
    670     AnalysisID PI = (*I)->getPassID();
    671     if (PI == AID)
    672       return *I;
    673 
    674     // If Pass not found then check the interfaces implemented by Immutable Pass
    675     const PassInfo *PassInf =
    676       PassRegistry::getPassRegistry()->getPassInfo(PI);
    677     assert(PassInf && "Expected all immutable passes to be initialized");
    678     const std::vector<const PassInfo*> &ImmPI =
    679       PassInf->getInterfacesImplemented();
    680     for (std::vector<const PassInfo*>::const_iterator II = ImmPI.begin(),
    681          EE = ImmPI.end(); II != EE; ++II) {
    682       if ((*II)->getTypeInfo() == AID)
    683         return *I;
    684     }
    685   }
    686 
    687   return 0;
    688 }
    689 
    690 // Print passes managed by this top level manager.
    691 void PMTopLevelManager::dumpPasses() const {
    692 
    693   if (PassDebugging < Structure)
    694     return;
    695 
    696   // Print out the immutable passes
    697   for (unsigned i = 0, e = ImmutablePasses.size(); i != e; ++i) {
    698     ImmutablePasses[i]->dumpPassStructure(0);
    699   }
    700 
    701   // Every class that derives from PMDataManager also derives from Pass
    702   // (sometimes indirectly), but there's no inheritance relationship
    703   // between PMDataManager and Pass, so we have to getAsPass to get
    704   // from a PMDataManager* to a Pass*.
    705   for (SmallVector<PMDataManager *, 8>::const_iterator I = PassManagers.begin(),
    706          E = PassManagers.end(); I != E; ++I)
    707     (*I)->getAsPass()->dumpPassStructure(1);
    708 }
    709 
    710 void PMTopLevelManager::dumpArguments() const {
    711 
    712   if (PassDebugging < Arguments)
    713     return;
    714 
    715   dbgs() << "Pass Arguments: ";
    716   for (SmallVector<ImmutablePass *, 8>::const_iterator I =
    717        ImmutablePasses.begin(), E = ImmutablePasses.end(); I != E; ++I)
    718     if (const PassInfo *PI =
    719         PassRegistry::getPassRegistry()->getPassInfo((*I)->getPassID())) {
    720       assert(PI && "Expected all immutable passes to be initialized");
    721       if (!PI->isAnalysisGroup())
    722         dbgs() << " -" << PI->getPassArgument();
    723     }
    724   for (SmallVector<PMDataManager *, 8>::const_iterator I = PassManagers.begin(),
    725          E = PassManagers.end(); I != E; ++I)
    726     (*I)->dumpPassArguments();
    727   dbgs() << "\n";
    728 }
    729 
    730 void PMTopLevelManager::initializeAllAnalysisInfo() {
    731   for (SmallVectorImpl<PMDataManager *>::iterator I = PassManagers.begin(),
    732          E = PassManagers.end(); I != E; ++I)
    733     (*I)->initializeAnalysisInfo();
    734 
    735   // Initailize other pass managers
    736   for (SmallVectorImpl<PMDataManager *>::iterator
    737        I = IndirectPassManagers.begin(), E = IndirectPassManagers.end();
    738        I != E; ++I)
    739     (*I)->initializeAnalysisInfo();
    740 
    741   for (DenseMap<Pass *, Pass *>::iterator DMI = LastUser.begin(),
    742         DME = LastUser.end(); DMI != DME; ++DMI) {
    743     DenseMap<Pass *, SmallPtrSet<Pass *, 8> >::iterator InvDMI =
    744       InversedLastUser.find(DMI->second);
    745     if (InvDMI != InversedLastUser.end()) {
    746       SmallPtrSet<Pass *, 8> &L = InvDMI->second;
    747       L.insert(DMI->first);
    748     } else {
    749       SmallPtrSet<Pass *, 8> L; L.insert(DMI->first);
    750       InversedLastUser[DMI->second] = L;
    751     }
    752   }
    753 }
    754 
    755 /// Destructor
    756 PMTopLevelManager::~PMTopLevelManager() {
    757   for (SmallVectorImpl<PMDataManager *>::iterator I = PassManagers.begin(),
    758          E = PassManagers.end(); I != E; ++I)
    759     delete *I;
    760 
    761   for (SmallVectorImpl<ImmutablePass *>::iterator
    762          I = ImmutablePasses.begin(), E = ImmutablePasses.end(); I != E; ++I)
    763     delete *I;
    764 
    765   for (DenseMap<Pass *, AnalysisUsage *>::iterator DMI = AnUsageMap.begin(),
    766          DME = AnUsageMap.end(); DMI != DME; ++DMI)
    767     delete DMI->second;
    768 }
    769 
    770 //===----------------------------------------------------------------------===//
    771 // PMDataManager implementation
    772 
    773 /// Augement AvailableAnalysis by adding analysis made available by pass P.
    774 void PMDataManager::recordAvailableAnalysis(Pass *P) {
    775   AnalysisID PI = P->getPassID();
    776 
    777   AvailableAnalysis[PI] = P;
    778 
    779   assert(!AvailableAnalysis.empty());
    780 
    781   // This pass is the current implementation of all of the interfaces it
    782   // implements as well.
    783   const PassInfo *PInf = PassRegistry::getPassRegistry()->getPassInfo(PI);
    784   if (PInf == 0) return;
    785   const std::vector<const PassInfo*> &II = PInf->getInterfacesImplemented();
    786   for (unsigned i = 0, e = II.size(); i != e; ++i)
    787     AvailableAnalysis[II[i]->getTypeInfo()] = P;
    788 }
    789 
    790 // Return true if P preserves high level analysis used by other
    791 // passes managed by this manager
    792 bool PMDataManager::preserveHigherLevelAnalysis(Pass *P) {
    793   AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
    794   if (AnUsage->getPreservesAll())
    795     return true;
    796 
    797   const AnalysisUsage::VectorType &PreservedSet = AnUsage->getPreservedSet();
    798   for (SmallVectorImpl<Pass *>::iterator I = HigherLevelAnalysis.begin(),
    799          E = HigherLevelAnalysis.end(); I  != E; ++I) {
    800     Pass *P1 = *I;
    801     if (P1->getAsImmutablePass() == 0 &&
    802         std::find(PreservedSet.begin(), PreservedSet.end(),
    803                   P1->getPassID()) ==
    804            PreservedSet.end())
    805       return false;
    806   }
    807 
    808   return true;
    809 }
    810 
    811 /// verifyPreservedAnalysis -- Verify analysis preserved by pass P.
    812 void PMDataManager::verifyPreservedAnalysis(Pass *P) {
    813   // Don't do this unless assertions are enabled.
    814 #ifdef NDEBUG
    815   return;
    816 #endif
    817   AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
    818   const AnalysisUsage::VectorType &PreservedSet = AnUsage->getPreservedSet();
    819 
    820   // Verify preserved analysis
    821   for (AnalysisUsage::VectorType::const_iterator I = PreservedSet.begin(),
    822          E = PreservedSet.end(); I != E; ++I) {
    823     AnalysisID AID = *I;
    824     if (Pass *AP = findAnalysisPass(AID, true)) {
    825       TimeRegion PassTimer(getPassTimer(AP));
    826       AP->verifyAnalysis();
    827     }
    828   }
    829 }
    830 
    831 /// Remove Analysis not preserved by Pass P
    832 void PMDataManager::removeNotPreservedAnalysis(Pass *P) {
    833   AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
    834   if (AnUsage->getPreservesAll())
    835     return;
    836 
    837   const AnalysisUsage::VectorType &PreservedSet = AnUsage->getPreservedSet();
    838   for (std::map<AnalysisID, Pass*>::iterator I = AvailableAnalysis.begin(),
    839          E = AvailableAnalysis.end(); I != E; ) {
    840     std::map<AnalysisID, Pass*>::iterator Info = I++;
    841     if (Info->second->getAsImmutablePass() == 0 &&
    842         std::find(PreservedSet.begin(), PreservedSet.end(), Info->first) ==
    843         PreservedSet.end()) {
    844       // Remove this analysis
    845       if (PassDebugging >= Details) {
    846         Pass *S = Info->second;
    847         dbgs() << " -- '" <<  P->getPassName() << "' is not preserving '";
    848         dbgs() << S->getPassName() << "'\n";
    849       }
    850       AvailableAnalysis.erase(Info);
    851     }
    852   }
    853 
    854   // Check inherited analysis also. If P is not preserving analysis
    855   // provided by parent manager then remove it here.
    856   for (unsigned Index = 0; Index < PMT_Last; ++Index) {
    857 
    858     if (!InheritedAnalysis[Index])
    859       continue;
    860 
    861     for (std::map<AnalysisID, Pass*>::iterator
    862            I = InheritedAnalysis[Index]->begin(),
    863            E = InheritedAnalysis[Index]->end(); I != E; ) {
    864       std::map<AnalysisID, Pass *>::iterator Info = I++;
    865       if (Info->second->getAsImmutablePass() == 0 &&
    866           std::find(PreservedSet.begin(), PreservedSet.end(), Info->first) ==
    867              PreservedSet.end()) {
    868         // Remove this analysis
    869         if (PassDebugging >= Details) {
    870           Pass *S = Info->second;
    871           dbgs() << " -- '" <<  P->getPassName() << "' is not preserving '";
    872           dbgs() << S->getPassName() << "'\n";
    873         }
    874         InheritedAnalysis[Index]->erase(Info);
    875       }
    876     }
    877   }
    878 }
    879 
    880 /// Remove analysis passes that are not used any longer
    881 void PMDataManager::removeDeadPasses(Pass *P, StringRef Msg,
    882                                      enum PassDebuggingString DBG_STR) {
    883 
    884   SmallVector<Pass *, 12> DeadPasses;
    885 
    886   // If this is a on the fly manager then it does not have TPM.
    887   if (!TPM)
    888     return;
    889 
    890   TPM->collectLastUses(DeadPasses, P);
    891 
    892   if (PassDebugging >= Details && !DeadPasses.empty()) {
    893     dbgs() << " -*- '" <<  P->getPassName();
    894     dbgs() << "' is the last user of following pass instances.";
    895     dbgs() << " Free these instances\n";
    896   }
    897 
    898   for (SmallVectorImpl<Pass *>::iterator I = DeadPasses.begin(),
    899          E = DeadPasses.end(); I != E; ++I)
    900     freePass(*I, Msg, DBG_STR);
    901 }
    902 
    903 void PMDataManager::freePass(Pass *P, StringRef Msg,
    904                              enum PassDebuggingString DBG_STR) {
    905   dumpPassInfo(P, FREEING_MSG, DBG_STR, Msg);
    906 
    907   {
    908     // If the pass crashes releasing memory, remember this.
    909     PassManagerPrettyStackEntry X(P);
    910     TimeRegion PassTimer(getPassTimer(P));
    911 
    912     P->releaseMemory();
    913   }
    914 
    915   AnalysisID PI = P->getPassID();
    916   if (const PassInfo *PInf = PassRegistry::getPassRegistry()->getPassInfo(PI)) {
    917     // Remove the pass itself (if it is not already removed).
    918     AvailableAnalysis.erase(PI);
    919 
    920     // Remove all interfaces this pass implements, for which it is also
    921     // listed as the available implementation.
    922     const std::vector<const PassInfo*> &II = PInf->getInterfacesImplemented();
    923     for (unsigned i = 0, e = II.size(); i != e; ++i) {
    924       std::map<AnalysisID, Pass*>::iterator Pos =
    925         AvailableAnalysis.find(II[i]->getTypeInfo());
    926       if (Pos != AvailableAnalysis.end() && Pos->second == P)
    927         AvailableAnalysis.erase(Pos);
    928     }
    929   }
    930 }
    931 
    932 /// Add pass P into the PassVector. Update
    933 /// AvailableAnalysis appropriately if ProcessAnalysis is true.
    934 void PMDataManager::add(Pass *P, bool ProcessAnalysis) {
    935   // This manager is going to manage pass P. Set up analysis resolver
    936   // to connect them.
    937   AnalysisResolver *AR = new AnalysisResolver(*this);
    938   P->setResolver(AR);
    939 
    940   // If a FunctionPass F is the last user of ModulePass info M
    941   // then the F's manager, not F, records itself as a last user of M.
    942   SmallVector<Pass *, 12> TransferLastUses;
    943 
    944   if (!ProcessAnalysis) {
    945     // Add pass
    946     PassVector.push_back(P);
    947     return;
    948   }
    949 
    950   // At the moment, this pass is the last user of all required passes.
    951   SmallVector<Pass *, 12> LastUses;
    952   SmallVector<Pass *, 8> RequiredPasses;
    953   SmallVector<AnalysisID, 8> ReqAnalysisNotAvailable;
    954 
    955   unsigned PDepth = this->getDepth();
    956 
    957   collectRequiredAnalysis(RequiredPasses,
    958                           ReqAnalysisNotAvailable, P);
    959   for (SmallVectorImpl<Pass *>::iterator I = RequiredPasses.begin(),
    960          E = RequiredPasses.end(); I != E; ++I) {
    961     Pass *PRequired = *I;
    962     unsigned RDepth = 0;
    963 
    964     assert(PRequired->getResolver() && "Analysis Resolver is not set");
    965     PMDataManager &DM = PRequired->getResolver()->getPMDataManager();
    966     RDepth = DM.getDepth();
    967 
    968     if (PDepth == RDepth)
    969       LastUses.push_back(PRequired);
    970     else if (PDepth > RDepth) {
    971       // Let the parent claim responsibility of last use
    972       TransferLastUses.push_back(PRequired);
    973       // Keep track of higher level analysis used by this manager.
    974       HigherLevelAnalysis.push_back(PRequired);
    975     } else
    976       llvm_unreachable("Unable to accommodate Required Pass");
    977   }
    978 
    979   // Set P as P's last user until someone starts using P.
    980   // However, if P is a Pass Manager then it does not need
    981   // to record its last user.
    982   if (P->getAsPMDataManager() == 0)
    983     LastUses.push_back(P);
    984   TPM->setLastUser(LastUses, P);
    985 
    986   if (!TransferLastUses.empty()) {
    987     Pass *My_PM = getAsPass();
    988     TPM->setLastUser(TransferLastUses, My_PM);
    989     TransferLastUses.clear();
    990   }
    991 
    992   // Now, take care of required analyses that are not available.
    993   for (SmallVectorImpl<AnalysisID>::iterator
    994          I = ReqAnalysisNotAvailable.begin(),
    995          E = ReqAnalysisNotAvailable.end() ;I != E; ++I) {
    996     const PassInfo *PI = PassRegistry::getPassRegistry()->getPassInfo(*I);
    997     Pass *AnalysisPass = PI->createPass();
    998     this->addLowerLevelRequiredPass(P, AnalysisPass);
    999   }
   1000 
   1001   // Take a note of analysis required and made available by this pass.
   1002   // Remove the analysis not preserved by this pass
   1003   removeNotPreservedAnalysis(P);
   1004   recordAvailableAnalysis(P);
   1005 
   1006   // Add pass
   1007   PassVector.push_back(P);
   1008 }
   1009 
   1010 
   1011 /// Populate RP with analysis pass that are required by
   1012 /// pass P and are available. Populate RP_NotAvail with analysis
   1013 /// pass that are required by pass P but are not available.
   1014 void PMDataManager::collectRequiredAnalysis(SmallVectorImpl<Pass *> &RP,
   1015                                        SmallVectorImpl<AnalysisID> &RP_NotAvail,
   1016                                             Pass *P) {
   1017   AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
   1018   const AnalysisUsage::VectorType &RequiredSet = AnUsage->getRequiredSet();
   1019   for (AnalysisUsage::VectorType::const_iterator
   1020          I = RequiredSet.begin(), E = RequiredSet.end(); I != E; ++I) {
   1021     if (Pass *AnalysisPass = findAnalysisPass(*I, true))
   1022       RP.push_back(AnalysisPass);
   1023     else
   1024       RP_NotAvail.push_back(*I);
   1025   }
   1026 
   1027   const AnalysisUsage::VectorType &IDs = AnUsage->getRequiredTransitiveSet();
   1028   for (AnalysisUsage::VectorType::const_iterator I = IDs.begin(),
   1029          E = IDs.end(); I != E; ++I) {
   1030     if (Pass *AnalysisPass = findAnalysisPass(*I, true))
   1031       RP.push_back(AnalysisPass);
   1032     else
   1033       RP_NotAvail.push_back(*I);
   1034   }
   1035 }
   1036 
   1037 // All Required analyses should be available to the pass as it runs!  Here
   1038 // we fill in the AnalysisImpls member of the pass so that it can
   1039 // successfully use the getAnalysis() method to retrieve the
   1040 // implementations it needs.
   1041 //
   1042 void PMDataManager::initializeAnalysisImpl(Pass *P) {
   1043   AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
   1044 
   1045   for (AnalysisUsage::VectorType::const_iterator
   1046          I = AnUsage->getRequiredSet().begin(),
   1047          E = AnUsage->getRequiredSet().end(); I != E; ++I) {
   1048     Pass *Impl = findAnalysisPass(*I, true);
   1049     if (Impl == 0)
   1050       // This may be analysis pass that is initialized on the fly.
   1051       // If that is not the case then it will raise an assert when it is used.
   1052       continue;
   1053     AnalysisResolver *AR = P->getResolver();
   1054     assert(AR && "Analysis Resolver is not set");
   1055     AR->addAnalysisImplsPair(*I, Impl);
   1056   }
   1057 }
   1058 
   1059 /// Find the pass that implements Analysis AID. If desired pass is not found
   1060 /// then return NULL.
   1061 Pass *PMDataManager::findAnalysisPass(AnalysisID AID, bool SearchParent) {
   1062 
   1063   // Check if AvailableAnalysis map has one entry.
   1064   std::map<AnalysisID, Pass*>::const_iterator I =  AvailableAnalysis.find(AID);
   1065 
   1066   if (I != AvailableAnalysis.end())
   1067     return I->second;
   1068 
   1069   // Search Parents through TopLevelManager
   1070   if (SearchParent)
   1071     return TPM->findAnalysisPass(AID);
   1072 
   1073   return NULL;
   1074 }
   1075 
   1076 // Print list of passes that are last used by P.
   1077 void PMDataManager::dumpLastUses(Pass *P, unsigned Offset) const{
   1078 
   1079   SmallVector<Pass *, 12> LUses;
   1080 
   1081   // If this is a on the fly manager then it does not have TPM.
   1082   if (!TPM)
   1083     return;
   1084 
   1085   TPM->collectLastUses(LUses, P);
   1086 
   1087   for (SmallVectorImpl<Pass *>::iterator I = LUses.begin(),
   1088          E = LUses.end(); I != E; ++I) {
   1089     llvm::dbgs() << "--" << std::string(Offset*2, ' ');
   1090     (*I)->dumpPassStructure(0);
   1091   }
   1092 }
   1093 
   1094 void PMDataManager::dumpPassArguments() const {
   1095   for (SmallVectorImpl<Pass *>::const_iterator I = PassVector.begin(),
   1096         E = PassVector.end(); I != E; ++I) {
   1097     if (PMDataManager *PMD = (*I)->getAsPMDataManager())
   1098       PMD->dumpPassArguments();
   1099     else
   1100       if (const PassInfo *PI =
   1101             PassRegistry::getPassRegistry()->getPassInfo((*I)->getPassID()))
   1102         if (!PI->isAnalysisGroup())
   1103           dbgs() << " -" << PI->getPassArgument();
   1104   }
   1105 }
   1106 
   1107 void PMDataManager::dumpPassInfo(Pass *P, enum PassDebuggingString S1,
   1108                                  enum PassDebuggingString S2,
   1109                                  StringRef Msg) {
   1110   if (PassDebugging < Executions)
   1111     return;
   1112   dbgs() << (void*)this << std::string(getDepth()*2+1, ' ');
   1113   switch (S1) {
   1114   case EXECUTION_MSG:
   1115     dbgs() << "Executing Pass '" << P->getPassName();
   1116     break;
   1117   case MODIFICATION_MSG:
   1118     dbgs() << "Made Modification '" << P->getPassName();
   1119     break;
   1120   case FREEING_MSG:
   1121     dbgs() << " Freeing Pass '" << P->getPassName();
   1122     break;
   1123   default:
   1124     break;
   1125   }
   1126   switch (S2) {
   1127   case ON_BASICBLOCK_MSG:
   1128     dbgs() << "' on BasicBlock '" << Msg << "'...\n";
   1129     break;
   1130   case ON_FUNCTION_MSG:
   1131     dbgs() << "' on Function '" << Msg << "'...\n";
   1132     break;
   1133   case ON_MODULE_MSG:
   1134     dbgs() << "' on Module '"  << Msg << "'...\n";
   1135     break;
   1136   case ON_REGION_MSG:
   1137     dbgs() << "' on Region '"  << Msg << "'...\n";
   1138     break;
   1139   case ON_LOOP_MSG:
   1140     dbgs() << "' on Loop '" << Msg << "'...\n";
   1141     break;
   1142   case ON_CG_MSG:
   1143     dbgs() << "' on Call Graph Nodes '" << Msg << "'...\n";
   1144     break;
   1145   default:
   1146     break;
   1147   }
   1148 }
   1149 
   1150 void PMDataManager::dumpRequiredSet(const Pass *P) const {
   1151   if (PassDebugging < Details)
   1152     return;
   1153 
   1154   AnalysisUsage analysisUsage;
   1155   P->getAnalysisUsage(analysisUsage);
   1156   dumpAnalysisUsage("Required", P, analysisUsage.getRequiredSet());
   1157 }
   1158 
   1159 void PMDataManager::dumpPreservedSet(const Pass *P) const {
   1160   if (PassDebugging < Details)
   1161     return;
   1162 
   1163   AnalysisUsage analysisUsage;
   1164   P->getAnalysisUsage(analysisUsage);
   1165   dumpAnalysisUsage("Preserved", P, analysisUsage.getPreservedSet());
   1166 }
   1167 
   1168 void PMDataManager::dumpAnalysisUsage(StringRef Msg, const Pass *P,
   1169                                    const AnalysisUsage::VectorType &Set) const {
   1170   assert(PassDebugging >= Details);
   1171   if (Set.empty())
   1172     return;
   1173   dbgs() << (void*)P << std::string(getDepth()*2+3, ' ') << Msg << " Analyses:";
   1174   for (unsigned i = 0; i != Set.size(); ++i) {
   1175     if (i) dbgs() << ',';
   1176     const PassInfo *PInf = PassRegistry::getPassRegistry()->getPassInfo(Set[i]);
   1177     if (!PInf) {
   1178       // Some preserved passes, such as AliasAnalysis, may not be initialized by
   1179       // all drivers.
   1180       dbgs() << " Uninitialized Pass";
   1181       continue;
   1182     }
   1183     dbgs() << ' ' << PInf->getPassName();
   1184   }
   1185   dbgs() << '\n';
   1186 }
   1187 
   1188 /// Add RequiredPass into list of lower level passes required by pass P.
   1189 /// RequiredPass is run on the fly by Pass Manager when P requests it
   1190 /// through getAnalysis interface.
   1191 /// This should be handled by specific pass manager.
   1192 void PMDataManager::addLowerLevelRequiredPass(Pass *P, Pass *RequiredPass) {
   1193   if (TPM) {
   1194     TPM->dumpArguments();
   1195     TPM->dumpPasses();
   1196   }
   1197 
   1198   // Module Level pass may required Function Level analysis info
   1199   // (e.g. dominator info). Pass manager uses on the fly function pass manager
   1200   // to provide this on demand. In that case, in Pass manager terminology,
   1201   // module level pass is requiring lower level analysis info managed by
   1202   // lower level pass manager.
   1203 
   1204   // When Pass manager is not able to order required analysis info, Pass manager
   1205   // checks whether any lower level manager will be able to provide this
   1206   // analysis info on demand or not.
   1207 #ifndef NDEBUG
   1208   dbgs() << "Unable to schedule '" << RequiredPass->getPassName();
   1209   dbgs() << "' required by '" << P->getPassName() << "'\n";
   1210 #endif
   1211   llvm_unreachable("Unable to schedule pass");
   1212 }
   1213 
   1214 Pass *PMDataManager::getOnTheFlyPass(Pass *P, AnalysisID PI, Function &F) {
   1215   llvm_unreachable("Unable to find on the fly pass");
   1216 }
   1217 
   1218 // Destructor
   1219 PMDataManager::~PMDataManager() {
   1220   for (SmallVectorImpl<Pass *>::iterator I = PassVector.begin(),
   1221          E = PassVector.end(); I != E; ++I)
   1222     delete *I;
   1223 }
   1224 
   1225 //===----------------------------------------------------------------------===//
   1226 // NOTE: Is this the right place to define this method ?
   1227 // getAnalysisIfAvailable - Return analysis result or null if it doesn't exist.
   1228 Pass *AnalysisResolver::getAnalysisIfAvailable(AnalysisID ID, bool dir) const {
   1229   return PM.findAnalysisPass(ID, dir);
   1230 }
   1231 
   1232 Pass *AnalysisResolver::findImplPass(Pass *P, AnalysisID AnalysisPI,
   1233                                      Function &F) {
   1234   return PM.getOnTheFlyPass(P, AnalysisPI, F);
   1235 }
   1236 
   1237 //===----------------------------------------------------------------------===//
   1238 // BBPassManager implementation
   1239 
   1240 /// Execute all of the passes scheduled for execution by invoking
   1241 /// runOnBasicBlock method.  Keep track of whether any of the passes modifies
   1242 /// the function, and if so, return true.
   1243 bool BBPassManager::runOnFunction(Function &F) {
   1244   if (F.isDeclaration())
   1245     return false;
   1246 
   1247   bool Changed = doInitialization(F);
   1248 
   1249   for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
   1250     for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
   1251       BasicBlockPass *BP = getContainedPass(Index);
   1252       bool LocalChanged = false;
   1253 
   1254       dumpPassInfo(BP, EXECUTION_MSG, ON_BASICBLOCK_MSG, I->getName());
   1255       dumpRequiredSet(BP);
   1256 
   1257       initializeAnalysisImpl(BP);
   1258 
   1259       {
   1260         // If the pass crashes, remember this.
   1261         PassManagerPrettyStackEntry X(BP, *I);
   1262         TimeRegion PassTimer(getPassTimer(BP));
   1263 
   1264         LocalChanged |= BP->runOnBasicBlock(*I);
   1265       }
   1266 
   1267       Changed |= LocalChanged;
   1268       if (LocalChanged)
   1269         dumpPassInfo(BP, MODIFICATION_MSG, ON_BASICBLOCK_MSG,
   1270                      I->getName());
   1271       dumpPreservedSet(BP);
   1272 
   1273       verifyPreservedAnalysis(BP);
   1274       removeNotPreservedAnalysis(BP);
   1275       recordAvailableAnalysis(BP);
   1276       removeDeadPasses(BP, I->getName(), ON_BASICBLOCK_MSG);
   1277     }
   1278 
   1279   return doFinalization(F) || Changed;
   1280 }
   1281 
   1282 // Implement doInitialization and doFinalization
   1283 bool BBPassManager::doInitialization(Module &M) {
   1284   bool Changed = false;
   1285 
   1286   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index)
   1287     Changed |= getContainedPass(Index)->doInitialization(M);
   1288 
   1289   return Changed;
   1290 }
   1291 
   1292 bool BBPassManager::doFinalization(Module &M) {
   1293   bool Changed = false;
   1294 
   1295   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index)
   1296     Changed |= getContainedPass(Index)->doFinalization(M);
   1297 
   1298   return Changed;
   1299 }
   1300 
   1301 bool BBPassManager::doInitialization(Function &F) {
   1302   bool Changed = false;
   1303 
   1304   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
   1305     BasicBlockPass *BP = getContainedPass(Index);
   1306     Changed |= BP->doInitialization(F);
   1307   }
   1308 
   1309   return Changed;
   1310 }
   1311 
   1312 bool BBPassManager::doFinalization(Function &F) {
   1313   bool Changed = false;
   1314 
   1315   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
   1316     BasicBlockPass *BP = getContainedPass(Index);
   1317     Changed |= BP->doFinalization(F);
   1318   }
   1319 
   1320   return Changed;
   1321 }
   1322 
   1323 
   1324 //===----------------------------------------------------------------------===//
   1325 // FunctionPassManager implementation
   1326 
   1327 /// Create new Function pass manager
   1328 FunctionPassManager::FunctionPassManager(Module *m) : M(m) {
   1329   FPM = new FunctionPassManagerImpl();
   1330   // FPM is the top level manager.
   1331   FPM->setTopLevelManager(FPM);
   1332 
   1333   AnalysisResolver *AR = new AnalysisResolver(*FPM);
   1334   FPM->setResolver(AR);
   1335 }
   1336 
   1337 FunctionPassManager::~FunctionPassManager() {
   1338   delete FPM;
   1339 }
   1340 
   1341 /// add - Add a pass to the queue of passes to run.  This passes
   1342 /// ownership of the Pass to the PassManager.  When the
   1343 /// PassManager_X is destroyed, the pass will be destroyed as well, so
   1344 /// there is no need to delete the pass. (TODO delete passes.)
   1345 /// This implies that all passes MUST be allocated with 'new'.
   1346 void FunctionPassManager::add(Pass *P) {
   1347   FPM->add(P);
   1348 }
   1349 
   1350 /// run - Execute all of the passes scheduled for execution.  Keep
   1351 /// track of whether any of the passes modifies the function, and if
   1352 /// so, return true.
   1353 ///
   1354 bool FunctionPassManager::run(Function &F) {
   1355   if (F.isMaterializable()) {
   1356     std::string errstr;
   1357     if (F.Materialize(&errstr))
   1358       report_fatal_error("Error reading bitcode file: " + Twine(errstr));
   1359   }
   1360   return FPM->run(F);
   1361 }
   1362 
   1363 
   1364 /// doInitialization - Run all of the initializers for the function passes.
   1365 ///
   1366 bool FunctionPassManager::doInitialization() {
   1367   return FPM->doInitialization(*M);
   1368 }
   1369 
   1370 /// doFinalization - Run all of the finalizers for the function passes.
   1371 ///
   1372 bool FunctionPassManager::doFinalization() {
   1373   return FPM->doFinalization(*M);
   1374 }
   1375 
   1376 //===----------------------------------------------------------------------===//
   1377 // FunctionPassManagerImpl implementation
   1378 //
   1379 bool FunctionPassManagerImpl::doInitialization(Module &M) {
   1380   bool Changed = false;
   1381 
   1382   dumpArguments();
   1383   dumpPasses();
   1384 
   1385   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
   1386     Changed |= getContainedManager(Index)->doInitialization(M);
   1387 
   1388   return Changed;
   1389 }
   1390 
   1391 bool FunctionPassManagerImpl::doFinalization(Module &M) {
   1392   bool Changed = false;
   1393 
   1394   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
   1395     Changed |= getContainedManager(Index)->doFinalization(M);
   1396 
   1397   return Changed;
   1398 }
   1399 
   1400 /// cleanup - After running all passes, clean up pass manager cache.
   1401 void FPPassManager::cleanup() {
   1402  for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
   1403     FunctionPass *FP = getContainedPass(Index);
   1404     AnalysisResolver *AR = FP->getResolver();
   1405     assert(AR && "Analysis Resolver is not set");
   1406     AR->clearAnalysisImpls();
   1407  }
   1408 }
   1409 
   1410 void FunctionPassManagerImpl::releaseMemoryOnTheFly() {
   1411   if (!wasRun)
   1412     return;
   1413   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index) {
   1414     FPPassManager *FPPM = getContainedManager(Index);
   1415     for (unsigned Index = 0; Index < FPPM->getNumContainedPasses(); ++Index) {
   1416       FPPM->getContainedPass(Index)->releaseMemory();
   1417     }
   1418   }
   1419   wasRun = false;
   1420 }
   1421 
   1422 // Execute all the passes managed by this top level manager.
   1423 // Return true if any function is modified by a pass.
   1424 bool FunctionPassManagerImpl::run(Function &F) {
   1425   bool Changed = false;
   1426   TimingInfo::createTheTimeInfo();
   1427 
   1428   initializeAllAnalysisInfo();
   1429   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
   1430     Changed |= getContainedManager(Index)->runOnFunction(F);
   1431 
   1432   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
   1433     getContainedManager(Index)->cleanup();
   1434 
   1435   wasRun = true;
   1436   return Changed;
   1437 }
   1438 
   1439 //===----------------------------------------------------------------------===//
   1440 // FPPassManager implementation
   1441 
   1442 char FPPassManager::ID = 0;
   1443 /// Print passes managed by this manager
   1444 void FPPassManager::dumpPassStructure(unsigned Offset) {
   1445   dbgs().indent(Offset*2) << "FunctionPass Manager\n";
   1446   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
   1447     FunctionPass *FP = getContainedPass(Index);
   1448     FP->dumpPassStructure(Offset + 1);
   1449     dumpLastUses(FP, Offset+1);
   1450   }
   1451 }
   1452 
   1453 
   1454 /// Execute all of the passes scheduled for execution by invoking
   1455 /// runOnFunction method.  Keep track of whether any of the passes modifies
   1456 /// the function, and if so, return true.
   1457 bool FPPassManager::runOnFunction(Function &F) {
   1458   if (F.isDeclaration())
   1459     return false;
   1460 
   1461   bool Changed = false;
   1462 
   1463   // Collect inherited analysis from Module level pass manager.
   1464   populateInheritedAnalysis(TPM->activeStack);
   1465 
   1466   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
   1467     FunctionPass *FP = getContainedPass(Index);
   1468     bool LocalChanged = false;
   1469 
   1470     dumpPassInfo(FP, EXECUTION_MSG, ON_FUNCTION_MSG, F.getName());
   1471     dumpRequiredSet(FP);
   1472 
   1473     initializeAnalysisImpl(FP);
   1474 
   1475     {
   1476       PassManagerPrettyStackEntry X(FP, F);
   1477       TimeRegion PassTimer(getPassTimer(FP));
   1478 
   1479       LocalChanged |= FP->runOnFunction(F);
   1480     }
   1481 
   1482     Changed |= LocalChanged;
   1483     if (LocalChanged)
   1484       dumpPassInfo(FP, MODIFICATION_MSG, ON_FUNCTION_MSG, F.getName());
   1485     dumpPreservedSet(FP);
   1486 
   1487     verifyPreservedAnalysis(FP);
   1488     removeNotPreservedAnalysis(FP);
   1489     recordAvailableAnalysis(FP);
   1490     removeDeadPasses(FP, F.getName(), ON_FUNCTION_MSG);
   1491   }
   1492   return Changed;
   1493 }
   1494 
   1495 bool FPPassManager::runOnModule(Module &M) {
   1496   bool Changed = doInitialization(M);
   1497 
   1498   for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
   1499     Changed |= runOnFunction(*I);
   1500 
   1501   return doFinalization(M) || Changed;
   1502 }
   1503 
   1504 bool FPPassManager::doInitialization(Module &M) {
   1505   bool Changed = false;
   1506 
   1507   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index)
   1508     Changed |= getContainedPass(Index)->doInitialization(M);
   1509 
   1510   return Changed;
   1511 }
   1512 
   1513 bool FPPassManager::doFinalization(Module &M) {
   1514   bool Changed = false;
   1515 
   1516   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index)
   1517     Changed |= getContainedPass(Index)->doFinalization(M);
   1518 
   1519   return Changed;
   1520 }
   1521 
   1522 //===----------------------------------------------------------------------===//
   1523 // MPPassManager implementation
   1524 
   1525 /// Execute all of the passes scheduled for execution by invoking
   1526 /// runOnModule method.  Keep track of whether any of the passes modifies
   1527 /// the module, and if so, return true.
   1528 bool
   1529 MPPassManager::runOnModule(Module &M) {
   1530   bool Changed = false;
   1531 
   1532   // Initialize on-the-fly passes
   1533   for (std::map<Pass *, FunctionPassManagerImpl *>::iterator
   1534        I = OnTheFlyManagers.begin(), E = OnTheFlyManagers.end();
   1535        I != E; ++I) {
   1536     FunctionPassManagerImpl *FPP = I->second;
   1537     Changed |= FPP->doInitialization(M);
   1538   }
   1539 
   1540   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
   1541     ModulePass *MP = getContainedPass(Index);
   1542     bool LocalChanged = false;
   1543 
   1544     dumpPassInfo(MP, EXECUTION_MSG, ON_MODULE_MSG, M.getModuleIdentifier());
   1545     dumpRequiredSet(MP);
   1546 
   1547     initializeAnalysisImpl(MP);
   1548 
   1549     {
   1550       PassManagerPrettyStackEntry X(MP, M);
   1551       TimeRegion PassTimer(getPassTimer(MP));
   1552 
   1553       LocalChanged |= MP->runOnModule(M);
   1554     }
   1555 
   1556     Changed |= LocalChanged;
   1557     if (LocalChanged)
   1558       dumpPassInfo(MP, MODIFICATION_MSG, ON_MODULE_MSG,
   1559                    M.getModuleIdentifier());
   1560     dumpPreservedSet(MP);
   1561 
   1562     verifyPreservedAnalysis(MP);
   1563     removeNotPreservedAnalysis(MP);
   1564     recordAvailableAnalysis(MP);
   1565     removeDeadPasses(MP, M.getModuleIdentifier(), ON_MODULE_MSG);
   1566   }
   1567 
   1568   // Finalize on-the-fly passes
   1569   for (std::map<Pass *, FunctionPassManagerImpl *>::iterator
   1570        I = OnTheFlyManagers.begin(), E = OnTheFlyManagers.end();
   1571        I != E; ++I) {
   1572     FunctionPassManagerImpl *FPP = I->second;
   1573     // We don't know when is the last time an on-the-fly pass is run,
   1574     // so we need to releaseMemory / finalize here
   1575     FPP->releaseMemoryOnTheFly();
   1576     Changed |= FPP->doFinalization(M);
   1577   }
   1578   return Changed;
   1579 }
   1580 
   1581 /// Add RequiredPass into list of lower level passes required by pass P.
   1582 /// RequiredPass is run on the fly by Pass Manager when P requests it
   1583 /// through getAnalysis interface.
   1584 void MPPassManager::addLowerLevelRequiredPass(Pass *P, Pass *RequiredPass) {
   1585   assert(P->getPotentialPassManagerType() == PMT_ModulePassManager &&
   1586          "Unable to handle Pass that requires lower level Analysis pass");
   1587   assert((P->getPotentialPassManagerType() <
   1588           RequiredPass->getPotentialPassManagerType()) &&
   1589          "Unable to handle Pass that requires lower level Analysis pass");
   1590 
   1591   FunctionPassManagerImpl *FPP = OnTheFlyManagers[P];
   1592   if (!FPP) {
   1593     FPP = new FunctionPassManagerImpl();
   1594     // FPP is the top level manager.
   1595     FPP->setTopLevelManager(FPP);
   1596 
   1597     OnTheFlyManagers[P] = FPP;
   1598   }
   1599   FPP->add(RequiredPass);
   1600 
   1601   // Register P as the last user of RequiredPass.
   1602   if (RequiredPass) {
   1603     SmallVector<Pass *, 1> LU;
   1604     LU.push_back(RequiredPass);
   1605     FPP->setLastUser(LU,  P);
   1606   }
   1607 }
   1608 
   1609 /// Return function pass corresponding to PassInfo PI, that is
   1610 /// required by module pass MP. Instantiate analysis pass, by using
   1611 /// its runOnFunction() for function F.
   1612 Pass* MPPassManager::getOnTheFlyPass(Pass *MP, AnalysisID PI, Function &F){
   1613   FunctionPassManagerImpl *FPP = OnTheFlyManagers[MP];
   1614   assert(FPP && "Unable to find on the fly pass");
   1615 
   1616   FPP->releaseMemoryOnTheFly();
   1617   FPP->run(F);
   1618   return ((PMTopLevelManager*)FPP)->findAnalysisPass(PI);
   1619 }
   1620 
   1621 
   1622 //===----------------------------------------------------------------------===//
   1623 // PassManagerImpl implementation
   1624 //
   1625 /// run - Execute all of the passes scheduled for execution.  Keep track of
   1626 /// whether any of the passes modifies the module, and if so, return true.
   1627 bool PassManagerImpl::run(Module &M) {
   1628   bool Changed = false;
   1629   TimingInfo::createTheTimeInfo();
   1630 
   1631   dumpArguments();
   1632   dumpPasses();
   1633 
   1634   initializeAllAnalysisInfo();
   1635   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
   1636     Changed |= getContainedManager(Index)->runOnModule(M);
   1637   return Changed;
   1638 }
   1639 
   1640 //===----------------------------------------------------------------------===//
   1641 // PassManager implementation
   1642 
   1643 /// Create new pass manager
   1644 PassManager::PassManager() {
   1645   PM = new PassManagerImpl();
   1646   // PM is the top level manager
   1647   PM->setTopLevelManager(PM);
   1648 }
   1649 
   1650 PassManager::~PassManager() {
   1651   delete PM;
   1652 }
   1653 
   1654 /// add - Add a pass to the queue of passes to run.  This passes ownership of
   1655 /// the Pass to the PassManager.  When the PassManager is destroyed, the pass
   1656 /// will be destroyed as well, so there is no need to delete the pass.  This
   1657 /// implies that all passes MUST be allocated with 'new'.
   1658 void PassManager::add(Pass *P) {
   1659   PM->add(P);
   1660 }
   1661 
   1662 /// run - Execute all of the passes scheduled for execution.  Keep track of
   1663 /// whether any of the passes modifies the module, and if so, return true.
   1664 bool PassManager::run(Module &M) {
   1665   return PM->run(M);
   1666 }
   1667 
   1668 //===----------------------------------------------------------------------===//
   1669 // TimingInfo Class - This class is used to calculate information about the
   1670 // amount of time each pass takes to execute.  This only happens with
   1671 // -time-passes is enabled on the command line.
   1672 //
   1673 bool llvm::TimePassesIsEnabled = false;
   1674 static cl::opt<bool,true>
   1675 EnableTiming("time-passes", cl::location(TimePassesIsEnabled),
   1676             cl::desc("Time each pass, printing elapsed time for each on exit"));
   1677 
   1678 // createTheTimeInfo - This method either initializes the TheTimeInfo pointer to
   1679 // a non null value (if the -time-passes option is enabled) or it leaves it
   1680 // null.  It may be called multiple times.
   1681 void TimingInfo::createTheTimeInfo() {
   1682   if (!TimePassesIsEnabled || TheTimeInfo) return;
   1683 
   1684   // Constructed the first time this is called, iff -time-passes is enabled.
   1685   // This guarantees that the object will be constructed before static globals,
   1686   // thus it will be destroyed before them.
   1687   static ManagedStatic<TimingInfo> TTI;
   1688   TheTimeInfo = &*TTI;
   1689 }
   1690 
   1691 /// If TimingInfo is enabled then start pass timer.
   1692 Timer *llvm::getPassTimer(Pass *P) {
   1693   if (TheTimeInfo)
   1694     return TheTimeInfo->getPassTimer(P);
   1695   return 0;
   1696 }
   1697 
   1698 //===----------------------------------------------------------------------===//
   1699 // PMStack implementation
   1700 //
   1701 
   1702 // Pop Pass Manager from the stack and clear its analysis info.
   1703 void PMStack::pop() {
   1704 
   1705   PMDataManager *Top = this->top();
   1706   Top->initializeAnalysisInfo();
   1707 
   1708   S.pop_back();
   1709 }
   1710 
   1711 // Push PM on the stack and set its top level manager.
   1712 void PMStack::push(PMDataManager *PM) {
   1713   assert(PM && "Unable to push. Pass Manager expected");
   1714   assert(PM->getDepth()==0 && "Pass Manager depth set too early");
   1715 
   1716   if (!this->empty()) {
   1717     assert(PM->getPassManagerType() > this->top()->getPassManagerType()
   1718            && "pushing bad pass manager to PMStack");
   1719     PMTopLevelManager *TPM = this->top()->getTopLevelManager();
   1720 
   1721     assert(TPM && "Unable to find top level manager");
   1722     TPM->addIndirectPassManager(PM);
   1723     PM->setTopLevelManager(TPM);
   1724     PM->setDepth(this->top()->getDepth()+1);
   1725   }
   1726   else {
   1727     assert((PM->getPassManagerType() == PMT_ModulePassManager
   1728            || PM->getPassManagerType() == PMT_FunctionPassManager)
   1729            && "pushing bad pass manager to PMStack");
   1730     PM->setDepth(1);
   1731   }
   1732 
   1733   S.push_back(PM);
   1734 }
   1735 
   1736 // Dump content of the pass manager stack.
   1737 void PMStack::dump() const {
   1738   for (std::vector<PMDataManager *>::const_iterator I = S.begin(),
   1739          E = S.end(); I != E; ++I)
   1740     dbgs() << (*I)->getAsPass()->getPassName() << ' ';
   1741 
   1742   if (!S.empty())
   1743     dbgs() << '\n';
   1744 }
   1745 
   1746 /// Find appropriate Module Pass Manager in the PM Stack and
   1747 /// add self into that manager.
   1748 void ModulePass::assignPassManager(PMStack &PMS,
   1749                                    PassManagerType PreferredType) {
   1750   // Find Module Pass Manager
   1751   while (!PMS.empty()) {
   1752     PassManagerType TopPMType = PMS.top()->getPassManagerType();
   1753     if (TopPMType == PreferredType)
   1754       break; // We found desired pass manager
   1755     else if (TopPMType > PMT_ModulePassManager)
   1756       PMS.pop();    // Pop children pass managers
   1757     else
   1758       break;
   1759   }
   1760   assert(!PMS.empty() && "Unable to find appropriate Pass Manager");
   1761   PMS.top()->add(this);
   1762 }
   1763 
   1764 /// Find appropriate Function Pass Manager or Call Graph Pass Manager
   1765 /// in the PM Stack and add self into that manager.
   1766 void FunctionPass::assignPassManager(PMStack &PMS,
   1767                                      PassManagerType PreferredType) {
   1768 
   1769   // Find Function Pass Manager
   1770   while (!PMS.empty()) {
   1771     if (PMS.top()->getPassManagerType() > PMT_FunctionPassManager)
   1772       PMS.pop();
   1773     else
   1774       break;
   1775   }
   1776 
   1777   // Create new Function Pass Manager if needed.
   1778   FPPassManager *FPP;
   1779   if (PMS.top()->getPassManagerType() == PMT_FunctionPassManager) {
   1780     FPP = (FPPassManager *)PMS.top();
   1781   } else {
   1782     assert(!PMS.empty() && "Unable to create Function Pass Manager");
   1783     PMDataManager *PMD = PMS.top();
   1784 
   1785     // [1] Create new Function Pass Manager
   1786     FPP = new FPPassManager();
   1787     FPP->populateInheritedAnalysis(PMS);
   1788 
   1789     // [2] Set up new manager's top level manager
   1790     PMTopLevelManager *TPM = PMD->getTopLevelManager();
   1791     TPM->addIndirectPassManager(FPP);
   1792 
   1793     // [3] Assign manager to manage this new manager. This may create
   1794     // and push new managers into PMS
   1795     FPP->assignPassManager(PMS, PMD->getPassManagerType());
   1796 
   1797     // [4] Push new manager into PMS
   1798     PMS.push(FPP);
   1799   }
   1800 
   1801   // Assign FPP as the manager of this pass.
   1802   FPP->add(this);
   1803 }
   1804 
   1805 /// Find appropriate Basic Pass Manager or Call Graph Pass Manager
   1806 /// in the PM Stack and add self into that manager.
   1807 void BasicBlockPass::assignPassManager(PMStack &PMS,
   1808                                        PassManagerType PreferredType) {
   1809   BBPassManager *BBP;
   1810 
   1811   // Basic Pass Manager is a leaf pass manager. It does not handle
   1812   // any other pass manager.
   1813   if (!PMS.empty() &&
   1814       PMS.top()->getPassManagerType() == PMT_BasicBlockPassManager) {
   1815     BBP = (BBPassManager *)PMS.top();
   1816   } else {
   1817     // If leaf manager is not Basic Block Pass manager then create new
   1818     // basic Block Pass manager.
   1819     assert(!PMS.empty() && "Unable to create BasicBlock Pass Manager");
   1820     PMDataManager *PMD = PMS.top();
   1821 
   1822     // [1] Create new Basic Block Manager
   1823     BBP = new BBPassManager();
   1824 
   1825     // [2] Set up new manager's top level manager
   1826     // Basic Block Pass Manager does not live by itself
   1827     PMTopLevelManager *TPM = PMD->getTopLevelManager();
   1828     TPM->addIndirectPassManager(BBP);
   1829 
   1830     // [3] Assign manager to manage this new manager. This may create
   1831     // and push new managers into PMS
   1832     BBP->assignPassManager(PMS, PreferredType);
   1833 
   1834     // [4] Push new manager into PMS
   1835     PMS.push(BBP);
   1836   }
   1837 
   1838   // Assign BBP as the manager of this pass.
   1839   BBP->add(this);
   1840 }
   1841 
   1842 PassManagerBase::~PassManagerBase() {}
   1843