lib/VMCore/PassManager.cpp

   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/DebugInfoProbe.h"
  18 #include "llvm/Assembly/PrintModulePass.h"
  19 #include "llvm/Assembly/Writer.h"
  20 #include "llvm/Support/CommandLine.h"
  21 #include "llvm/Support/Debug.h"
  22 #include "llvm/Support/Timer.h"
  23 #include "llvm/Module.h"
  24 #include "llvm/Support/ErrorHandling.h"
  25 #include "llvm/Support/ManagedStatic.h"
  26 #include "llvm/Support/PassNameParser.h"
  27 #include "llvm/Support/raw_ostream.h"
  28 #include "llvm/Support/Mutex.h"
  29 #include "llvm/ADT/StringMap.h"
  30 #include <algorithm>
  31 #include <cstdio>
  32 #include <map>
  33 using namespace llvm;
  34
  35 // See PassManagers.h for Pass Manager infrastructure overview.
  36
  37 namespace llvm {
  38
  39 //===----------------------------------------------------------------------===//
  40 // Pass debugging information.  Often it is useful to find out what pass is
  41 // running when a crash occurs in a utility.  When this library is compiled with
  42 // debugging on, a command line option (--debug-pass) is enabled that causes the
  43 // pass name to be printed before it executes.
  44 //
  45
  46 // Different debug levels that can be enabled...
  47 enum PassDebugLevel {
  48   None, Arguments, Structure, Executions, Details
  49 };
  50
  51 static cl::opt<enum PassDebugLevel>
  52 PassDebugging("debug-pass", cl::Hidden,
  53                   cl::desc("Print PassManager debugging information"),
  54                   cl::values(
  55   clEnumVal(None      , "disable debug output"),
  56   clEnumVal(Arguments , "print pass arguments to pass to 'opt'"),
  57   clEnumVal(Structure , "print pass structure before run()"),
  58   clEnumVal(Executions, "print pass name before it is executed"),
  59   clEnumVal(Details   , "print pass details when it is executed"),
  60                              clEnumValEnd));
  61
  62 typedef llvm::cl::list<const llvm::PassInfo *, bool, PassNameParser>
  63 PassOptionList;
  64
  65 // Print IR out before/after specified passes.
  66 static PassOptionList
  67 PrintBefore("print-before",
  68             llvm::cl::desc("Print IR before specified passes"),
  69             cl::Hidden);
  70
  71 static PassOptionList
  72 PrintAfter("print-after",
  73            llvm::cl::desc("Print IR after specified passes"),
  74            cl::Hidden);
  75
  76 static cl::opt<bool>
  77 PrintBeforeAll("print-before-all",
  78                llvm::cl::desc("Print IR before each pass"),
  79                cl::init(false));
  80 static cl::opt<bool>
  81 PrintAfterAll("print-after-all",
  82               llvm::cl::desc("Print IR after each pass"),
  83               cl::init(false));
  84
  85 /// This is a helper to determine whether to print IR before or
  86 /// after a pass.
  87
  88 static bool ShouldPrintBeforeOrAfterPass(const void *PassID,
  89                                          PassOptionList &PassesToPrint) {
  90   if (const llvm::PassInfo *PI =
  91       PassRegistry::getPassRegistry()->getPassInfo(PassID)) {
  92     for (unsigned i = 0, ie = PassesToPrint.size(); i < ie; ++i) {
  93       const llvm::PassInfo *PassInf = PassesToPrint[i];
  94       if (PassInf)
  95         if (PassInf->getPassArgument() == PI->getPassArgument()) {
  96           return true;
  97         }
  98     }
  99   }
 100   return false;
 101 }
 102
 103
 104 /// This is a utility to check whether a pass should have IR dumped
 105 /// before it.
 106 static bool ShouldPrintBeforePass(const void *PassID) {
 107   return PrintBeforeAll || ShouldPrintBeforeOrAfterPass(PassID, PrintBefore);
 108 }
 109
 110 /// This is a utility to check whether a pass should have IR dumped
 111 /// after it.
 112 static bool ShouldPrintAfterPass(const void *PassID) {
 113   return PrintAfterAll || ShouldPrintBeforeOrAfterPass(PassID, PrintAfter);
 114 }
 115
 116 } // End of llvm namespace
 117
 118 /// isPassDebuggingExecutionsOrMore - Return true if -debug-pass=Executions
 119 /// or higher is specified.
 120 bool PMDataManager::isPassDebuggingExecutionsOrMore() const {
 121   return PassDebugging >= Executions;
 122 }
 123
 124
 125
 126
 127 void PassManagerPrettyStackEntry::print(raw_ostream &OS) const {
 128   if (V == 0 && M == 0)
 129     OS << "Releasing pass '";
 130   else
 131     OS << "Running pass '";
 132
 133   OS << P->getPassName() << "'";
 134
 135   if (M) {
 136     OS << " on module '" << M->getModuleIdentifier() << "'.\n";
 137     return;
 138   }
 139   if (V == 0) {
 140     OS << '\n';
 141     return;
 142   }
 143
 144   OS << " on ";
 145   if (isa<Function>(V))
 146     OS << "function";
 147   else if (isa<BasicBlock>(V))
 148     OS << "basic block";
 149   else
 150     OS << "value";
 151
 152   OS << " '";
 153   WriteAsOperand(OS, V, /*PrintTy=*/false, M);
 154   OS << "'\n";
 155 }
 156
 157
 158 namespace {
 159
 160 //===----------------------------------------------------------------------===//
 161 // BBPassManager
 162 //
 163 /// BBPassManager manages BasicBlockPass. It batches all the
 164 /// pass together and sequence them to process one basic block before
 165 /// processing next basic block.
 166 class BBPassManager : public PMDataManager, public FunctionPass {
 167
 168 public:
 169   static char ID;
 170   explicit BBPassManager(int Depth)
 171     : PMDataManager(Depth), FunctionPass(ID) {}
 172
 173   /// Execute all of the passes scheduled for execution.  Keep track of
 174   /// whether any of the passes modifies the function, and if so, return true.
 175   bool runOnFunction(Function &F);
 176
 177   /// Pass Manager itself does not invalidate any analysis info.
 178   void getAnalysisUsage(AnalysisUsage &Info) const {
 179     Info.setPreservesAll();
 180   }
 181
 182   bool doInitialization(Module &M);
 183   bool doInitialization(Function &F);
 184   bool doFinalization(Module &M);
 185   bool doFinalization(Function &F);
 186
 187   virtual PMDataManager *getAsPMDataManager() { return this; }
 188   virtual Pass *getAsPass() { return this; }
 189
 190   virtual const char *getPassName() const {
 191     return "BasicBlock Pass Manager";
 192   }
 193
 194   // Print passes managed by this manager
 195   void dumpPassStructure(unsigned Offset) {
 196     llvm::dbgs() << std::string(Offset*2, ' ') << "BasicBlockPass Manager\n";
 197     for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
 198       BasicBlockPass *BP = getContainedPass(Index);
 199       BP->dumpPassStructure(Offset + 1);
 200       dumpLastUses(BP, Offset+1);
 201     }
 202   }
 203
 204   BasicBlockPass *getContainedPass(unsigned N) {
 205     assert(N < PassVector.size() && "Pass number out of range!");
 206     BasicBlockPass *BP = static_cast<BasicBlockPass *>(PassVector[N]);
 207     return BP;
 208   }
 209
 210   virtual PassManagerType getPassManagerType() const {
 211     return PMT_BasicBlockPassManager;
 212   }
 213 };
 214
 215 char BBPassManager::ID = 0;
 216 }
 217
 218 namespace llvm {
 219
 220 //===----------------------------------------------------------------------===//
 221 // FunctionPassManagerImpl
 222 //
 223 /// FunctionPassManagerImpl manages FPPassManagers
 224 class FunctionPassManagerImpl : public Pass,
 225                                 public PMDataManager,
 226                                 public PMTopLevelManager {
 227 private:
 228   bool wasRun;
 229 public:
 230   static char ID;
 231   explicit FunctionPassManagerImpl(int Depth) :
 232     Pass(PT_PassManager, ID), PMDataManager(Depth),
 233     PMTopLevelManager(new FPPassManager(1)), wasRun(false) {}
 234
 235   /// add - Add a pass to the queue of passes to run.  This passes ownership of
 236   /// the Pass to the PassManager.  When the PassManager is destroyed, the pass
 237   /// will be destroyed as well, so there is no need to delete the pass.  This
 238   /// implies that all passes MUST be allocated with 'new'.
 239   void add(Pass *P) {
 240     schedulePass(P);
 241   }
 242
 243   /// createPrinterPass - Get a function printer pass.
 244   Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const {
 245     return createPrintFunctionPass(Banner, &O);
 246   }
 247
 248   // Prepare for running an on the fly pass, freeing memory if needed
 249   // from a previous run.
 250   void releaseMemoryOnTheFly();
 251
 252   /// run - Execute all of the passes scheduled for execution.  Keep track of
 253   /// whether any of the passes modifies the module, and if so, return true.
 254   bool run(Function &F);
 255
 256   /// doInitialization - Run all of the initializers for the function passes.
 257   ///
 258   bool doInitialization(Module &M);
 259
 260   /// doFinalization - Run all of the finalizers for the function passes.
 261   ///
 262   bool doFinalization(Module &M);
 263
 264
 265   virtual PMDataManager *getAsPMDataManager() { return this; }
 266   virtual Pass *getAsPass() { return this; }
 267
 268   /// Pass Manager itself does not invalidate any analysis info.
 269   void getAnalysisUsage(AnalysisUsage &Info) const {
 270     Info.setPreservesAll();
 271   }
 272
 273   void addTopLevelPass(Pass *P) {
 274     if (ImmutablePass *IP = P->getAsImmutablePass()) {
 275       // P is a immutable pass and it will be managed by this
 276       // top level manager. Set up analysis resolver to connect them.
 277       AnalysisResolver *AR = new AnalysisResolver(*this);
 278       P->setResolver(AR);
 279       initializeAnalysisImpl(P);
 280       addImmutablePass(IP);
 281       recordAvailableAnalysis(IP);
 282     } else {
 283       P->assignPassManager(activeStack, PMT_FunctionPassManager);
 284     }
 285
 286   }
 287
 288   FPPassManager *getContainedManager(unsigned N) {
 289     assert(N < PassManagers.size() && "Pass number out of range!");
 290     FPPassManager *FP = static_cast<FPPassManager *>(PassManagers[N]);
 291     return FP;
 292   }
 293 };
 294
 295 char FunctionPassManagerImpl::ID = 0;
 296
 297 //===----------------------------------------------------------------------===//
 298 // MPPassManager
 299 //
 300 /// MPPassManager manages ModulePasses and function pass managers.
 301 /// It batches all Module passes and function pass managers together and
 302 /// sequences them to process one module.
 303 class MPPassManager : public Pass, public PMDataManager {
 304 public:
 305   static char ID;
 306   explicit MPPassManager(int Depth) :
 307     Pass(PT_PassManager, ID), PMDataManager(Depth) { }
 308
 309   // Delete on the fly managers.
 310   virtual ~MPPassManager() {
 311     for (std::map<Pass *, FunctionPassManagerImpl *>::iterator
 312            I = OnTheFlyManagers.begin(), E = OnTheFlyManagers.end();
 313          I != E; ++I) {
 314       FunctionPassManagerImpl *FPP = I->second;
 315       delete FPP;
 316     }
 317   }
 318
 319   /// createPrinterPass - Get a module printer pass.
 320   Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const {
 321     return createPrintModulePass(&O, false, Banner);
 322   }
 323
 324   /// run - Execute all of the passes scheduled for execution.  Keep track of
 325   /// whether any of the passes modifies the module, and if so, return true.
 326   bool runOnModule(Module &M);
 327
 328   /// Pass Manager itself does not invalidate any analysis info.
 329   void getAnalysisUsage(AnalysisUsage &Info) const {
 330     Info.setPreservesAll();
 331   }
 332
 333   /// Add RequiredPass into list of lower level passes required by pass P.
 334   /// RequiredPass is run on the fly by Pass Manager when P requests it
 335   /// through getAnalysis interface.
 336   virtual void addLowerLevelRequiredPass(Pass *P, Pass *RequiredPass);
 337
 338   /// Return function pass corresponding to PassInfo PI, that is
 339   /// required by module pass MP. Instantiate analysis pass, by using
 340   /// its runOnFunction() for function F.
 341   virtual Pass* getOnTheFlyPass(Pass *MP, AnalysisID PI, Function &F);
 342
 343   virtual const char *getPassName() const {
 344     return "Module Pass Manager";
 345   }
 346
 347   virtual PMDataManager *getAsPMDataManager() { return this; }
 348   virtual Pass *getAsPass() { return this; }
 349
 350   // Print passes managed by this manager
 351   void dumpPassStructure(unsigned Offset) {
 352     llvm::dbgs() << std::string(Offset*2, ' ') << "ModulePass Manager\n";
 353     for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
 354       ModulePass *MP = getContainedPass(Index);
 355       MP->dumpPassStructure(Offset + 1);
 356       std::map<Pass *, FunctionPassManagerImpl *>::const_iterator I =
 357         OnTheFlyManagers.find(MP);
 358       if (I != OnTheFlyManagers.end())
 359         I->second->dumpPassStructure(Offset + 2);
 360       dumpLastUses(MP, Offset+1);
 361     }
 362   }
 363
 364   ModulePass *getContainedPass(unsigned N) {
 365     assert(N < PassVector.size() && "Pass number out of range!");
 366     return static_cast<ModulePass *>(PassVector[N]);
 367   }
 368
 369   virtual PassManagerType getPassManagerType() const {
 370     return PMT_ModulePassManager;
 371   }
 372
 373  private:
 374   /// Collection of on the fly FPPassManagers. These managers manage
 375   /// function passes that are required by module passes.
 376   std::map<Pass *, FunctionPassManagerImpl *> OnTheFlyManagers;
 377 };
 378
 379 char MPPassManager::ID = 0;
 380 //===----------------------------------------------------------------------===//
 381 // PassManagerImpl
 382 //
 383
 384 /// PassManagerImpl manages MPPassManagers
 385 class PassManagerImpl : public Pass,
 386                         public PMDataManager,
 387                         public PMTopLevelManager {
 388
 389 public:
 390   static char ID;
 391   explicit PassManagerImpl(int Depth) :
 392     Pass(PT_PassManager, ID), PMDataManager(Depth),
 393                               PMTopLevelManager(new MPPassManager(1)) {}
 394
 395   /// add - Add a pass to the queue of passes to run.  This passes ownership of
 396   /// the Pass to the PassManager.  When the PassManager is destroyed, the pass
 397   /// will be destroyed as well, so there is no need to delete the pass.  This
 398   /// implies that all passes MUST be allocated with 'new'.
 399   void add(Pass *P) {
 400     schedulePass(P);
 401   }
 402
 403   /// createPrinterPass - Get a module printer pass.
 404   Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const {
 405     return createPrintModulePass(&O, false, Banner);
 406   }
 407
 408   /// run - Execute all of the passes scheduled for execution.  Keep track of
 409   /// whether any of the passes modifies the module, and if so, return true.
 410   bool run(Module &M);
 411
 412   /// Pass Manager itself does not invalidate any analysis info.
 413   void getAnalysisUsage(AnalysisUsage &Info) const {
 414     Info.setPreservesAll();
 415   }
 416
 417   void addTopLevelPass(Pass *P) {
 418     if (ImmutablePass *IP = P->getAsImmutablePass()) {
 419       // P is a immutable pass and it will be managed by this
 420       // top level manager. Set up analysis resolver to connect them.
 421       AnalysisResolver *AR = new AnalysisResolver(*this);
 422       P->setResolver(AR);
 423       initializeAnalysisImpl(P);
 424       addImmutablePass(IP);
 425       recordAvailableAnalysis(IP);
 426     } else {
 427       P->assignPassManager(activeStack, PMT_ModulePassManager);
 428     }
 429   }
 430
 431   virtual PMDataManager *getAsPMDataManager() { return this; }
 432   virtual Pass *getAsPass() { return this; }
 433
 434   MPPassManager *getContainedManager(unsigned N) {
 435     assert(N < PassManagers.size() && "Pass number out of range!");
 436     MPPassManager *MP = static_cast<MPPassManager *>(PassManagers[N]);
 437     return MP;
 438   }
 439 };
 440
 441 char PassManagerImpl::ID = 0;
 442 } // End of llvm namespace
 443
 444 namespace {
 445
 446 //===----------------------------------------------------------------------===//
 447 // DebugInfoProbe
 448
 449 static DebugInfoProbeInfo *TheDebugProbe;
 450 static void createDebugInfoProbe() {
 451   if (TheDebugProbe) return;
 452
 453   // Constructed the first time this is called. This guarantees that the
 454   // object will be constructed, if -enable-debug-info-probe is set,
 455   // before static globals, thus it will be destroyed before them.
 456   static ManagedStatic<DebugInfoProbeInfo> DIP;
 457   TheDebugProbe = &*DIP;
 458 }
 459
 460 //===----------------------------------------------------------------------===//
 461 /// TimingInfo Class - This class is used to calculate information about the
 462 /// amount of time each pass takes to execute.  This only happens when
 463 /// -time-passes is enabled on the command line.
 464 ///
 465
 466 static ManagedStatic<sys::SmartMutex<true> > TimingInfoMutex;
 467
 468 class TimingInfo {
 469   DenseMap<Pass*, Timer*> TimingData;
 470   TimerGroup TG;
 471 public:
 472   // Use 'create' member to get this.
 473   TimingInfo() : TG("... Pass execution timing report ...") {}
 474
 475   // TimingDtor - Print out information about timing information
 476   ~TimingInfo() {
 477     // Delete all of the timers, which accumulate their info into the
 478     // TimerGroup.
 479     for (DenseMap<Pass*, Timer*>::iterator I = TimingData.begin(),
 480          E = TimingData.end(); I != E; ++I)
 481       delete I->second;
 482     // TimerGroup is deleted next, printing the report.
 483   }
 484
 485   // createTheTimeInfo - This method either initializes the TheTimeInfo pointer
 486   // to a non null value (if the -time-passes option is enabled) or it leaves it
 487   // null.  It may be called multiple times.
 488   static void createTheTimeInfo();
 489
 490   /// getPassTimer - Return the timer for the specified pass if it exists.
 491   Timer *getPassTimer(Pass *P) {
 492     if (P->getAsPMDataManager())
 493       return 0;
 494
 495     sys::SmartScopedLock<true> Lock(*TimingInfoMutex);
 496     Timer *&T = TimingData[P];
 497     if (T == 0)
 498       T = new Timer(P->getPassName(), TG);
 499     return T;
 500   }
 501 };
 502
 503 } // End of anon namespace
 504
 505 static TimingInfo *TheTimeInfo;
 506
 507 //===----------------------------------------------------------------------===//
 508 // PMTopLevelManager implementation
 509
 510 /// Initialize top level manager. Create first pass manager.
 511 PMTopLevelManager::PMTopLevelManager(PMDataManager *PMDM) {
 512   PMDM->setTopLevelManager(this);
 513   addPassManager(PMDM);
 514   activeStack.push(PMDM);
 515 }
 516
 517 /// Set pass P as the last user of the given analysis passes.
 518 void
 519 PMTopLevelManager::setLastUser(const SmallVectorImpl<Pass *> &AnalysisPasses,
 520                                Pass *P) {
 521   unsigned PDepth = 0;
 522   if (P->getResolver())
 523     PDepth = P->getResolver()->getPMDataManager().getDepth();
 524
 525   for (SmallVectorImpl<Pass *>::const_iterator I = AnalysisPasses.begin(),
 526          E = AnalysisPasses.end(); I != E; ++I) {
 527     Pass *AP = *I;
 528     LastUser[AP] = P;
 529
 530     if (P == AP)
 531       continue;
 532
 533     // Update the last users of passes that are required transitive by AP.
 534     AnalysisUsage *AnUsage = findAnalysisUsage(AP);
 535     const AnalysisUsage::VectorType &IDs = AnUsage->getRequiredTransitiveSet();
 536     SmallVector<Pass *, 12> LastUses;
 537     SmallVector<Pass *, 12> LastPMUses;
 538     for (AnalysisUsage::VectorType::const_iterator I = IDs.begin(),
 539          E = IDs.end(); I != E; ++I) {
 540       Pass *AnalysisPass = findAnalysisPass(*I);
 541       assert(AnalysisPass && "Expected analysis pass to exist.");
 542       AnalysisResolver *AR = AnalysisPass->getResolver();
 543       assert(AR && "Expected analysis resolver to exist.");
 544       unsigned APDepth = AR->getPMDataManager().getDepth();
 545
 546       if (PDepth == APDepth)
 547         LastUses.push_back(AnalysisPass);
 548       else if (PDepth > APDepth)
 549         LastPMUses.push_back(AnalysisPass);
 550     }
 551
 552     setLastUser(LastUses, P);
 553
 554     // If this pass has a corresponding pass manager, push higher level
 555     // analysis to this pass manager.
 556     if (P->getResolver())
 557       setLastUser(LastPMUses, P->getResolver()->getPMDataManager().getAsPass());
 558
 559
 560     // If AP is the last user of other passes then make P last user of
 561     // such passes.
 562     for (DenseMap<Pass *, Pass *>::iterator LUI = LastUser.begin(),
 563            LUE = LastUser.end(); LUI != LUE; ++LUI) {
 564       if (LUI->second == AP)
 565         // DenseMap iterator is not invalidated here because
 566         // this is just updating existing entries.
 567         LastUser[LUI->first] = P;
 568     }
 569   }
 570 }
 571
 572 /// Collect passes whose last user is P
 573 void PMTopLevelManager::collectLastUses(SmallVectorImpl<Pass *> &LastUses,
 574                                         Pass *P) {
 575   DenseMap<Pass *, SmallPtrSet<Pass *, 8> >::iterator DMI =
 576     InversedLastUser.find(P);
 577   if (DMI == InversedLastUser.end())
 578     return;
 579
 580   SmallPtrSet<Pass *, 8> &LU = DMI->second;
 581   for (SmallPtrSet<Pass *, 8>::iterator I = LU.begin(),
 582          E = LU.end(); I != E; ++I) {
 583     LastUses.push_back(*I);
 584   }
 585
 586 }
 587
 588 AnalysisUsage *PMTopLevelManager::findAnalysisUsage(Pass *P) {
 589   AnalysisUsage *AnUsage = NULL;
 590   DenseMap<Pass *, AnalysisUsage *>::iterator DMI = AnUsageMap.find(P);
 591   if (DMI != AnUsageMap.end())
 592     AnUsage = DMI->second;
 593   else {
 594     AnUsage = new AnalysisUsage();
 595     P->getAnalysisUsage(*AnUsage);
 596     AnUsageMap[P] = AnUsage;
 597   }
 598   return AnUsage;
 599 }
 600
 601 /// Schedule pass P for execution. Make sure that passes required by
 602 /// P are run before P is run. Update analysis info maintained by
 603 /// the manager. Remove dead passes. This is a recursive function.
 604 void PMTopLevelManager::schedulePass(Pass *P) {
 605
 606   // TODO : Allocate function manager for this pass, other wise required set
 607   // may be inserted into previous function manager
 608
 609   // Give pass a chance to prepare the stage.
 610   P->preparePassManager(activeStack);
 611
 612   // If P is an analysis pass and it is available then do not
 613   // generate the analysis again. Stale analysis info should not be
 614   // available at this point.
 615   const PassInfo *PI =
 616     PassRegistry::getPassRegistry()->getPassInfo(P->getPassID());
 617   if (PI && PI->isAnalysis() && findAnalysisPass(P->getPassID())) {
 618     delete P;
 619     return;
 620   }
 621
 622   AnalysisUsage *AnUsage = findAnalysisUsage(P);
 623
 624   bool checkAnalysis = true;
 625   while (checkAnalysis) {
 626     checkAnalysis = false;
 627
 628     const AnalysisUsage::VectorType &RequiredSet = AnUsage->getRequiredSet();
 629     for (AnalysisUsage::VectorType::const_iterator I = RequiredSet.begin(),
 630            E = RequiredSet.end(); I != E; ++I) {
 631
 632       Pass *AnalysisPass = findAnalysisPass(*I);
 633       if (!AnalysisPass) {
 634         const PassInfo *PI = PassRegistry::getPassRegistry()->getPassInfo(*I);
 635         AnalysisPass = PI->createPass();
 636         if (P->getPotentialPassManagerType () ==
 637             AnalysisPass->getPotentialPassManagerType())
 638           // Schedule analysis pass that is managed by the same pass manager.
 639           schedulePass(AnalysisPass);
 640         else if (P->getPotentialPassManagerType () >
 641                  AnalysisPass->getPotentialPassManagerType()) {
 642           // Schedule analysis pass that is managed by a new manager.
 643           schedulePass(AnalysisPass);
 644           // Recheck analysis passes to ensure that required analyses that
 645           // are already checked are still available.
 646           checkAnalysis = true;
 647         }
 648         else
 649           // Do not schedule this analysis. Lower level analsyis
 650           // passes are run on the fly.
 651           delete AnalysisPass;
 652       }
 653     }
 654   }
 655
 656   // Now all required passes are available.
 657   addTopLevelPass(P);
 658 }
 659
 660 /// Find the pass that implements Analysis AID. Search immutable
 661 /// passes and all pass managers. If desired pass is not found
 662 /// then return NULL.
 663 Pass *PMTopLevelManager::findAnalysisPass(AnalysisID AID) {
 664
 665   // Check pass managers
 666   for (SmallVectorImpl<PMDataManager *>::iterator I = PassManagers.begin(),
 667          E = PassManagers.end(); I != E; ++I)
 668     if (Pass *P = (*I)->findAnalysisPass(AID, false))
 669       return P;
 670
 671   // Check other pass managers
 672   for (SmallVectorImpl<PMDataManager *>::iterator
 673          I = IndirectPassManagers.begin(),
 674          E = IndirectPassManagers.end(); I != E; ++I)
 675     if (Pass *P = (*I)->findAnalysisPass(AID, false))
 676       return P;
 677
 678   // Check the immutable passes. Iterate in reverse order so that we find
 679   // the most recently registered passes first.
 680   for (SmallVector<ImmutablePass *, 8>::reverse_iterator I =
 681        ImmutablePasses.rbegin(), E = ImmutablePasses.rend(); I != E; ++I) {
 682     AnalysisID PI = (*I)->getPassID();
 683     if (PI == AID)
 684       return *I;
 685
 686     // If Pass not found then check the interfaces implemented by Immutable Pass
 687     const PassInfo *PassInf =
 688       PassRegistry::getPassRegistry()->getPassInfo(PI);
 689     const std::vector<const PassInfo*> &ImmPI =
 690       PassInf->getInterfacesImplemented();
 691     for (std::vector<const PassInfo*>::const_iterator II = ImmPI.begin(),
 692          EE = ImmPI.end(); II != EE; ++II) {
 693       if ((*II)->getTypeInfo() == AID)
 694         return *I;
 695     }
 696   }
 697
 698   return 0;
 699 }
 700
 701 // Print passes managed by this top level manager.
 702 void PMTopLevelManager::dumpPasses() const {
 703
 704   if (PassDebugging < Structure)
 705     return;
 706
 707   // Print out the immutable passes
 708   for (unsigned i = 0, e = ImmutablePasses.size(); i != e; ++i) {
 709     ImmutablePasses[i]->dumpPassStructure(0);
 710   }
 711
 712   // Every class that derives from PMDataManager also derives from Pass
 713   // (sometimes indirectly), but there's no inheritance relationship
 714   // between PMDataManager and Pass, so we have to getAsPass to get
 715   // from a PMDataManager* to a Pass*.
 716   for (SmallVector<PMDataManager *, 8>::const_iterator I = PassManagers.begin(),
 717          E = PassManagers.end(); I != E; ++I)
 718     (*I)->getAsPass()->dumpPassStructure(1);
 719 }
 720
 721 void PMTopLevelManager::dumpArguments() const {
 722
 723   if (PassDebugging < Arguments)
 724     return;
 725
 726   dbgs() << "Pass Arguments: ";
 727   for (SmallVector<ImmutablePass *, 8>::const_iterator I =
 728        ImmutablePasses.begin(), E = ImmutablePasses.end(); I != E; ++I)
 729     if (const PassInfo *PI =
 730           PassRegistry::getPassRegistry()->getPassInfo((*I)->getPassID()))
 731       if (!PI->isAnalysisGroup())
 732         dbgs() << " -" << PI->getPassArgument();
 733   for (SmallVector<PMDataManager *, 8>::const_iterator I = PassManagers.begin(),
 734          E = PassManagers.end(); I != E; ++I)
 735     (*I)->dumpPassArguments();
 736   dbgs() << "\n";
 737 }
 738
 739 void PMTopLevelManager::initializeAllAnalysisInfo() {
 740   for (SmallVectorImpl<PMDataManager *>::iterator I = PassManagers.begin(),
 741          E = PassManagers.end(); I != E; ++I)
 742     (*I)->initializeAnalysisInfo();
 743
 744   // Initailize other pass managers
 745   for (SmallVectorImpl<PMDataManager *>::iterator
 746        I = IndirectPassManagers.begin(), E = IndirectPassManagers.end();
 747        I != E; ++I)
 748     (*I)->initializeAnalysisInfo();
 749
 750   for (DenseMap<Pass *, Pass *>::iterator DMI = LastUser.begin(),
 751         DME = LastUser.end(); DMI != DME; ++DMI) {
 752     DenseMap<Pass *, SmallPtrSet<Pass *, 8> >::iterator InvDMI =
 753       InversedLastUser.find(DMI->second);
 754     if (InvDMI != InversedLastUser.end()) {
 755       SmallPtrSet<Pass *, 8> &L = InvDMI->second;
 756       L.insert(DMI->first);
 757     } else {
 758       SmallPtrSet<Pass *, 8> L; L.insert(DMI->first);
 759       InversedLastUser[DMI->second] = L;
 760     }
 761   }
 762 }
 763
 764 /// Destructor
 765 PMTopLevelManager::~PMTopLevelManager() {
 766   for (SmallVectorImpl<PMDataManager *>::iterator I = PassManagers.begin(),
 767          E = PassManagers.end(); I != E; ++I)
 768     delete *I;
 769
 770   for (SmallVectorImpl<ImmutablePass *>::iterator
 771          I = ImmutablePasses.begin(), E = ImmutablePasses.end(); I != E; ++I)
 772     delete *I;
 773
 774   for (DenseMap<Pass *, AnalysisUsage *>::iterator DMI = AnUsageMap.begin(),
 775          DME = AnUsageMap.end(); DMI != DME; ++DMI)
 776     delete DMI->second;
 777 }
 778
 779 //===----------------------------------------------------------------------===//
 780 // PMDataManager implementation
 781
 782 /// Augement AvailableAnalysis by adding analysis made available by pass P.
 783 void PMDataManager::recordAvailableAnalysis(Pass *P) {
 784   AnalysisID PI = P->getPassID();
 785
 786   AvailableAnalysis[PI] = P;
 787
 788   assert(!AvailableAnalysis.empty());
 789
 790   // This pass is the current implementation of all of the interfaces it
 791   // implements as well.
 792   const PassInfo *PInf = PassRegistry::getPassRegistry()->getPassInfo(PI);
 793   if (PInf == 0) return;
 794   const std::vector<const PassInfo*> &II = PInf->getInterfacesImplemented();
 795   for (unsigned i = 0, e = II.size(); i != e; ++i)
 796     AvailableAnalysis[II[i]->getTypeInfo()] = P;
 797 }
 798
 799 // Return true if P preserves high level analysis used by other
 800 // passes managed by this manager
 801 bool PMDataManager::preserveHigherLevelAnalysis(Pass *P) {
 802   AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
 803   if (AnUsage->getPreservesAll())
 804     return true;
 805
 806   const AnalysisUsage::VectorType &PreservedSet = AnUsage->getPreservedSet();
 807   for (SmallVectorImpl<Pass *>::iterator I = HigherLevelAnalysis.begin(),
 808          E = HigherLevelAnalysis.end(); I  != E; ++I) {
 809     Pass *P1 = *I;
 810     if (P1->getAsImmutablePass() == 0 &&
 811         std::find(PreservedSet.begin(), PreservedSet.end(),
 812                   P1->getPassID()) ==
 813            PreservedSet.end())
 814       return false;
 815   }
 816
 817   return true;
 818 }
 819
 820 /// verifyPreservedAnalysis -- Verify analysis preserved by pass P.
 821 void PMDataManager::verifyPreservedAnalysis(Pass *P) {
 822   // Don't do this unless assertions are enabled.
 823 #ifdef NDEBUG
 824   return;
 825 #endif
 826   AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
 827   const AnalysisUsage::VectorType &PreservedSet = AnUsage->getPreservedSet();
 828
 829   // Verify preserved analysis
 830   for (AnalysisUsage::VectorType::const_iterator I = PreservedSet.begin(),
 831          E = PreservedSet.end(); I != E; ++I) {
 832     AnalysisID AID = *I;
 833     if (Pass *AP = findAnalysisPass(AID, true)) {
 834       TimeRegion PassTimer(getPassTimer(AP));
 835       AP->verifyAnalysis();
 836     }
 837   }
 838 }
 839
 840 /// Remove Analysis not preserved by Pass P
 841 void PMDataManager::removeNotPreservedAnalysis(Pass *P) {
 842   AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
 843   if (AnUsage->getPreservesAll())
 844     return;
 845
 846   const AnalysisUsage::VectorType &PreservedSet = AnUsage->getPreservedSet();
 847   for (std::map<AnalysisID, Pass*>::iterator I = AvailableAnalysis.begin(),
 848          E = AvailableAnalysis.end(); I != E; ) {
 849     std::map<AnalysisID, Pass*>::iterator Info = I++;
 850     if (Info->second->getAsImmutablePass() == 0 &&
 851         std::find(PreservedSet.begin(), PreservedSet.end(), Info->first) ==
 852         PreservedSet.end()) {
 853       // Remove this analysis
 854       if (PassDebugging >= Details) {
 855         Pass *S = Info->second;
 856         dbgs() << " -- '" <<  P->getPassName() << "' is not preserving '";
 857         dbgs() << S->getPassName() << "'\n";
 858       }
 859       AvailableAnalysis.erase(Info);
 860     }
 861   }
 862
 863   // Check inherited analysis also. If P is not preserving analysis
 864   // provided by parent manager then remove it here.
 865   for (unsigned Index = 0; Index < PMT_Last; ++Index) {
 866
 867     if (!InheritedAnalysis[Index])
 868       continue;
 869
 870     for (std::map<AnalysisID, Pass*>::iterator
 871            I = InheritedAnalysis[Index]->begin(),
 872            E = InheritedAnalysis[Index]->end(); I != E; ) {
 873       std::map<AnalysisID, Pass *>::iterator Info = I++;
 874       if (Info->second->getAsImmutablePass() == 0 &&
 875           std::find(PreservedSet.begin(), PreservedSet.end(), Info->first) ==
 876              PreservedSet.end()) {
 877         // Remove this analysis
 878         if (PassDebugging >= Details) {
 879           Pass *S = Info->second;
 880           dbgs() << " -- '" <<  P->getPassName() << "' is not preserving '";
 881           dbgs() << S->getPassName() << "'\n";
 882         }
 883         InheritedAnalysis[Index]->erase(Info);
 884       }
 885     }
 886   }
 887 }
 888
 889 /// Remove analysis passes that are not used any longer
 890 void PMDataManager::removeDeadPasses(Pass *P, StringRef Msg,
 891                                      enum PassDebuggingString DBG_STR) {
 892
 893   SmallVector<Pass *, 12> DeadPasses;
 894
 895   // If this is a on the fly manager then it does not have TPM.
 896   if (!TPM)
 897     return;
 898
 899   TPM->collectLastUses(DeadPasses, P);
 900
 901   if (PassDebugging >= Details && !DeadPasses.empty()) {
 902     dbgs() << " -*- '" <<  P->getPassName();
 903     dbgs() << "' is the last user of following pass instances.";
 904     dbgs() << " Free these instances\n";
 905   }
 906
 907   for (SmallVectorImpl<Pass *>::iterator I = DeadPasses.begin(),
 908          E = DeadPasses.end(); I != E; ++I)
 909     freePass(*I, Msg, DBG_STR);
 910 }
 911
 912 void PMDataManager::freePass(Pass *P, StringRef Msg,
 913                              enum PassDebuggingString DBG_STR) {
 914   dumpPassInfo(P, FREEING_MSG, DBG_STR, Msg);
 915
 916   {
 917     // If the pass crashes releasing memory, remember this.
 918     PassManagerPrettyStackEntry X(P);
 919     TimeRegion PassTimer(getPassTimer(P));
 920
 921     P->releaseMemory();
 922   }
 923
 924   AnalysisID PI = P->getPassID();
 925   if (const PassInfo *PInf = PassRegistry::getPassRegistry()->getPassInfo(PI)) {
 926     // Remove the pass itself (if it is not already removed).
 927     AvailableAnalysis.erase(PI);
 928
 929     // Remove all interfaces this pass implements, for which it is also
 930     // listed as the available implementation.
 931     const std::vector<const PassInfo*> &II = PInf->getInterfacesImplemented();
 932     for (unsigned i = 0, e = II.size(); i != e; ++i) {
 933       std::map<AnalysisID, Pass*>::iterator Pos =
 934         AvailableAnalysis.find(II[i]->getTypeInfo());
 935       if (Pos != AvailableAnalysis.end() && Pos->second == P)
 936         AvailableAnalysis.erase(Pos);
 937     }
 938   }
 939 }
 940
 941 /// Add pass P into the PassVector. Update
 942 /// AvailableAnalysis appropriately if ProcessAnalysis is true.
 943 void PMDataManager::add(Pass *P, bool ProcessAnalysis) {
 944   // This manager is going to manage pass P. Set up analysis resolver
 945   // to connect them.
 946   AnalysisResolver *AR = new AnalysisResolver(*this);
 947   P->setResolver(AR);
 948
 949   // If a FunctionPass F is the last user of ModulePass info M
 950   // then the F's manager, not F, records itself as a last user of M.
 951   SmallVector<Pass *, 12> TransferLastUses;
 952
 953   if (!ProcessAnalysis) {
 954     // Add pass
 955     PassVector.push_back(P);
 956     return;
 957   }
 958
 959   // At the moment, this pass is the last user of all required passes.
 960   SmallVector<Pass *, 12> LastUses;
 961   SmallVector<Pass *, 8> RequiredPasses;
 962   SmallVector<AnalysisID, 8> ReqAnalysisNotAvailable;
 963
 964   unsigned PDepth = this->getDepth();
 965
 966   collectRequiredAnalysis(RequiredPasses,
 967                           ReqAnalysisNotAvailable, P);
 968   for (SmallVectorImpl<Pass *>::iterator I = RequiredPasses.begin(),
 969          E = RequiredPasses.end(); I != E; ++I) {
 970     Pass *PRequired = *I;
 971     unsigned RDepth = 0;
 972
 973     assert(PRequired->getResolver() && "Analysis Resolver is not set");
 974     PMDataManager &DM = PRequired->getResolver()->getPMDataManager();
 975     RDepth = DM.getDepth();
 976
 977     if (PDepth == RDepth)
 978       LastUses.push_back(PRequired);
 979     else if (PDepth > RDepth) {
 980       // Let the parent claim responsibility of last use
 981       TransferLastUses.push_back(PRequired);
 982       // Keep track of higher level analysis used by this manager.
 983       HigherLevelAnalysis.push_back(PRequired);
 984     } else
 985       llvm_unreachable("Unable to accomodate Required Pass");
 986   }
 987
 988   // Set P as P's last user until someone starts using P.
 989   // However, if P is a Pass Manager then it does not need
 990   // to record its last user.
 991   if (P->getAsPMDataManager() == 0)
 992     LastUses.push_back(P);
 993   TPM->setLastUser(LastUses, P);
 994
 995   if (!TransferLastUses.empty()) {
 996     Pass *My_PM = getAsPass();
 997     TPM->setLastUser(TransferLastUses, My_PM);
 998     TransferLastUses.clear();
 999   }
1000
1001   // Now, take care of required analyses that are not available.
1002   for (SmallVectorImpl<AnalysisID>::iterator
1003          I = ReqAnalysisNotAvailable.begin(),
1004          E = ReqAnalysisNotAvailable.end() ;I != E; ++I) {
1005     const PassInfo *PI = PassRegistry::getPassRegistry()->getPassInfo(*I);
1006     Pass *AnalysisPass = PI->createPass();
1007     this->addLowerLevelRequiredPass(P, AnalysisPass);
1008   }
1009
1010   // Take a note of analysis required and made available by this pass.
1011   // Remove the analysis not preserved by this pass
1012   removeNotPreservedAnalysis(P);
1013   recordAvailableAnalysis(P);
1014
1015   // Add pass
1016   PassVector.push_back(P);
1017 }
1018
1019
1020 /// Populate RP with analysis pass that are required by
1021 /// pass P and are available. Populate RP_NotAvail with analysis
1022 /// pass that are required by pass P but are not available.
1023 void PMDataManager::collectRequiredAnalysis(SmallVectorImpl<Pass *> &RP,
1024                                        SmallVectorImpl<AnalysisID> &RP_NotAvail,
1025                                             Pass *P) {
1026   AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
1027   const AnalysisUsage::VectorType &RequiredSet = AnUsage->getRequiredSet();
1028   for (AnalysisUsage::VectorType::const_iterator
1029          I = RequiredSet.begin(), E = RequiredSet.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   const AnalysisUsage::VectorType &IDs = AnUsage->getRequiredTransitiveSet();
1037   for (AnalysisUsage::VectorType::const_iterator I = IDs.begin(),
1038          E = IDs.end(); I != E; ++I) {
1039     if (Pass *AnalysisPass = findAnalysisPass(*I, true))
1040       RP.push_back(AnalysisPass);
1041     else
1042       RP_NotAvail.push_back(*I);
1043   }
1044 }
1045
1046 // All Required analyses should be available to the pass as it runs!  Here
1047 // we fill in the AnalysisImpls member of the pass so that it can
1048 // successfully use the getAnalysis() method to retrieve the
1049 // implementations it needs.
1050 //
1051 void PMDataManager::initializeAnalysisImpl(Pass *P) {
1052   AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
1053
1054   for (AnalysisUsage::VectorType::const_iterator
1055          I = AnUsage->getRequiredSet().begin(),
1056          E = AnUsage->getRequiredSet().end(); I != E; ++I) {
1057     Pass *Impl = findAnalysisPass(*I, true);
1058     if (Impl == 0)
1059       // This may be analysis pass that is initialized on the fly.
1060       // If that is not the case then it will raise an assert when it is used.
1061       continue;
1062     AnalysisResolver *AR = P->getResolver();
1063     assert(AR && "Analysis Resolver is not set");
1064     AR->addAnalysisImplsPair(*I, Impl);
1065   }
1066 }
1067
1068 /// Find the pass that implements Analysis AID. If desired pass is not found
1069 /// then return NULL.
1070 Pass *PMDataManager::findAnalysisPass(AnalysisID AID, bool SearchParent) {
1071
1072   // Check if AvailableAnalysis map has one entry.
1073   std::map<AnalysisID, Pass*>::const_iterator I =  AvailableAnalysis.find(AID);
1074
1075   if (I != AvailableAnalysis.end())
1076     return I->second;
1077
1078   // Search Parents through TopLevelManager
1079   if (SearchParent)
1080     return TPM->findAnalysisPass(AID);
1081
1082   return NULL;
1083 }
1084
1085 // Print list of passes that are last used by P.
1086 void PMDataManager::dumpLastUses(Pass *P, unsigned Offset) const{
1087
1088   SmallVector<Pass *, 12> LUses;
1089
1090   // If this is a on the fly manager then it does not have TPM.
1091   if (!TPM)
1092     return;
1093
1094   TPM->collectLastUses(LUses, P);
1095
1096   for (SmallVectorImpl<Pass *>::iterator I = LUses.begin(),
1097          E = LUses.end(); I != E; ++I) {
1098     llvm::dbgs() << "--" << std::string(Offset*2, ' ');
1099     (*I)->dumpPassStructure(0);
1100   }
1101 }
1102
1103 void PMDataManager::dumpPassArguments() const {
1104   for (SmallVectorImpl<Pass *>::const_iterator I = PassVector.begin(),
1105         E = PassVector.end(); I != E; ++I) {
1106     if (PMDataManager *PMD = (*I)->getAsPMDataManager())
1107       PMD->dumpPassArguments();
1108     else
1109       if (const PassInfo *PI =
1110             PassRegistry::getPassRegistry()->getPassInfo((*I)->getPassID()))
1111         if (!PI->isAnalysisGroup())
1112           dbgs() << " -" << PI->getPassArgument();
1113   }
1114 }
1115
1116 void PMDataManager::dumpPassInfo(Pass *P, enum PassDebuggingString S1,
1117                                  enum PassDebuggingString S2,
1118                                  StringRef Msg) {
1119   if (PassDebugging < Executions)
1120     return;
1121   dbgs() << (void*)this << std::string(getDepth()*2+1, ' ');
1122   switch (S1) {
1123   case EXECUTION_MSG:
1124     dbgs() << "Executing Pass '" << P->getPassName();
1125     break;
1126   case MODIFICATION_MSG:
1127     dbgs() << "Made Modification '" << P->getPassName();
1128     break;
1129   case FREEING_MSG:
1130     dbgs() << " Freeing Pass '" << P->getPassName();
1131     break;
1132   default:
1133     break;
1134   }
1135   switch (S2) {
1136   case ON_BASICBLOCK_MSG:
1137     dbgs() << "' on BasicBlock '" << Msg << "'...\n";
1138     break;
1139   case ON_FUNCTION_MSG:
1140     dbgs() << "' on Function '" << Msg << "'...\n";
1141     break;
1142   case ON_MODULE_MSG:
1143     dbgs() << "' on Module '"  << Msg << "'...\n";
1144     break;
1145   case ON_REGION_MSG:
1146     dbgs() << "' on Region '"  << Msg << "'...\n";
1147     break;
1148   case ON_LOOP_MSG:
1149     dbgs() << "' on Loop '" << Msg << "'...\n";
1150     break;
1151   case ON_CG_MSG:
1152     dbgs() << "' on Call Graph Nodes '" << Msg << "'...\n";
1153     break;
1154   default:
1155     break;
1156   }
1157 }
1158
1159 void PMDataManager::dumpRequiredSet(const Pass *P) const {
1160   if (PassDebugging < Details)
1161     return;
1162
1163   AnalysisUsage analysisUsage;
1164   P->getAnalysisUsage(analysisUsage);
1165   dumpAnalysisUsage("Required", P, analysisUsage.getRequiredSet());
1166 }
1167
1168 void PMDataManager::dumpPreservedSet(const Pass *P) const {
1169   if (PassDebugging < Details)
1170     return;
1171
1172   AnalysisUsage analysisUsage;
1173   P->getAnalysisUsage(analysisUsage);
1174   dumpAnalysisUsage("Preserved", P, analysisUsage.getPreservedSet());
1175 }
1176
1177 void PMDataManager::dumpAnalysisUsage(StringRef Msg, const Pass *P,
1178                                    const AnalysisUsage::VectorType &Set) const {
1179   assert(PassDebugging >= Details);
1180   if (Set.empty())
1181     return;
1182   dbgs() << (void*)P << std::string(getDepth()*2+3, ' ') << Msg << " Analyses:";
1183   for (unsigned i = 0; i != Set.size(); ++i) {
1184     if (i) dbgs() << ',';
1185     const PassInfo *PInf = PassRegistry::getPassRegistry()->getPassInfo(Set[i]);
1186     dbgs() << ' ' << PInf->getPassName();
1187   }
1188   dbgs() << '\n';
1189 }
1190
1191 /// Add RequiredPass into list of lower level passes required by pass P.
1192 /// RequiredPass is run on the fly by Pass Manager when P requests it
1193 /// through getAnalysis interface.
1194 /// This should be handled by specific pass manager.
1195 void PMDataManager::addLowerLevelRequiredPass(Pass *P, Pass *RequiredPass) {
1196   if (TPM) {
1197     TPM->dumpArguments();
1198     TPM->dumpPasses();
1199   }
1200
1201   // Module Level pass may required Function Level analysis info
1202   // (e.g. dominator info). Pass manager uses on the fly function pass manager
1203   // to provide this on demand. In that case, in Pass manager terminology,
1204   // module level pass is requiring lower level analysis info managed by
1205   // lower level pass manager.
1206
1207   // When Pass manager is not able to order required analysis info, Pass manager
1208   // checks whether any lower level manager will be able to provide this
1209   // analysis info on demand or not.
1210 #ifndef NDEBUG
1211   dbgs() << "Unable to schedule '" << RequiredPass->getPassName();
1212   dbgs() << "' required by '" << P->getPassName() << "'\n";
1213 #endif
1214   llvm_unreachable("Unable to schedule pass");
1215 }
1216
1217 Pass *PMDataManager::getOnTheFlyPass(Pass *P, AnalysisID PI, Function &F) {
1218   assert(0 && "Unable to find on the fly pass");
1219   return NULL;
1220 }
1221
1222 // Destructor
1223 PMDataManager::~PMDataManager() {
1224   for (SmallVectorImpl<Pass *>::iterator I = PassVector.begin(),
1225          E = PassVector.end(); I != E; ++I)
1226     delete *I;
1227 }
1228
1229 //===----------------------------------------------------------------------===//
1230 // NOTE: Is this the right place to define this method ?
1231 // getAnalysisIfAvailable - Return analysis result or null if it doesn't exist.
1232 Pass *AnalysisResolver::getAnalysisIfAvailable(AnalysisID ID, bool dir) const {
1233   return PM.findAnalysisPass(ID, dir);
1234 }
1235
1236 Pass *AnalysisResolver::findImplPass(Pass *P, AnalysisID AnalysisPI,
1237                                      Function &F) {
1238   return PM.getOnTheFlyPass(P, AnalysisPI, F);
1239 }
1240
1241 //===----------------------------------------------------------------------===//
1242 // BBPassManager implementation
1243
1244 /// Execute all of the passes scheduled for execution by invoking
1245 /// runOnBasicBlock method.  Keep track of whether any of the passes modifies
1246 /// the function, and if so, return true.
1247 bool BBPassManager::runOnFunction(Function &F) {
1248   if (F.isDeclaration())
1249     return false;
1250
1251   bool Changed = doInitialization(F);
1252
1253   for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
1254     for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1255       BasicBlockPass *BP = getContainedPass(Index);
1256       bool LocalChanged = false;
1257
1258       dumpPassInfo(BP, EXECUTION_MSG, ON_BASICBLOCK_MSG, I->getName());
1259       dumpRequiredSet(BP);
1260
1261       initializeAnalysisImpl(BP);
1262
1263       {
1264         // If the pass crashes, remember this.
1265         PassManagerPrettyStackEntry X(BP, *I);
1266         TimeRegion PassTimer(getPassTimer(BP));
1267
1268         LocalChanged |= BP->runOnBasicBlock(*I);
1269       }
1270
1271       Changed |= LocalChanged;
1272       if (LocalChanged)
1273         dumpPassInfo(BP, MODIFICATION_MSG, ON_BASICBLOCK_MSG,
1274                      I->getName());
1275       dumpPreservedSet(BP);
1276
1277       verifyPreservedAnalysis(BP);
1278       removeNotPreservedAnalysis(BP);
1279       recordAvailableAnalysis(BP);
1280       removeDeadPasses(BP, I->getName(), ON_BASICBLOCK_MSG);
1281     }
1282
1283   return doFinalization(F) || Changed;
1284 }
1285
1286 // Implement doInitialization and doFinalization
1287 bool BBPassManager::doInitialization(Module &M) {
1288   bool Changed = false;
1289
1290   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index)
1291     Changed |= getContainedPass(Index)->doInitialization(M);
1292
1293   return Changed;
1294 }
1295
1296 bool BBPassManager::doFinalization(Module &M) {
1297   bool Changed = false;
1298
1299   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index)
1300     Changed |= getContainedPass(Index)->doFinalization(M);
1301
1302   return Changed;
1303 }
1304
1305 bool BBPassManager::doInitialization(Function &F) {
1306   bool Changed = false;
1307
1308   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1309     BasicBlockPass *BP = getContainedPass(Index);
1310     Changed |= BP->doInitialization(F);
1311   }
1312
1313   return Changed;
1314 }
1315
1316 bool BBPassManager::doFinalization(Function &F) {
1317   bool Changed = false;
1318
1319   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1320     BasicBlockPass *BP = getContainedPass(Index);
1321     Changed |= BP->doFinalization(F);
1322   }
1323
1324   return Changed;
1325 }
1326
1327
1328 //===----------------------------------------------------------------------===//
1329 // FunctionPassManager implementation
1330
1331 /// Create new Function pass manager
1332 FunctionPassManager::FunctionPassManager(Module *m) : M(m) {
1333   FPM = new FunctionPassManagerImpl(0);
1334   // FPM is the top level manager.
1335   FPM->setTopLevelManager(FPM);
1336
1337   AnalysisResolver *AR = new AnalysisResolver(*FPM);
1338   FPM->setResolver(AR);
1339 }
1340
1341 FunctionPassManager::~FunctionPassManager() {
1342   delete FPM;
1343 }
1344
1345 /// addImpl - Add a pass to the queue of passes to run, without
1346 /// checking whether to add a printer pass.
1347 void FunctionPassManager::addImpl(Pass *P) {
1348   FPM->add(P);
1349 }
1350
1351 /// add - Add a pass to the queue of passes to run.  This passes
1352 /// ownership of the Pass to the PassManager.  When the
1353 /// PassManager_X is destroyed, the pass will be destroyed as well, so
1354 /// there is no need to delete the pass. (TODO delete passes.)
1355 /// This implies that all passes MUST be allocated with 'new'.
1356 void FunctionPassManager::add(Pass *P) {
1357   // If this is a not a function pass, don't add a printer for it.
1358   const void *PassID = P->getPassID();
1359   if (P->getPassKind() == PT_Function)
1360     if (ShouldPrintBeforePass(PassID))
1361       addImpl(P->createPrinterPass(dbgs(), std::string("*** IR Dump Before ")
1362                                    + P->getPassName() + " ***"));
1363
1364   addImpl(P);
1365
1366   if (P->getPassKind() == PT_Function)
1367     if (ShouldPrintAfterPass(PassID))
1368       addImpl(P->createPrinterPass(dbgs(), std::string("*** IR Dump After ")
1369                                    + P->getPassName() + " ***"));
1370 }
1371
1372 /// run - Execute all of the passes scheduled for execution.  Keep
1373 /// track of whether any of the passes modifies the function, and if
1374 /// so, return true.
1375 ///
1376 bool FunctionPassManager::run(Function &F) {
1377   if (F.isMaterializable()) {
1378     std::string errstr;
1379     if (F.Materialize(&errstr))
1380       report_fatal_error("Error reading bitcode file: " + Twine(errstr));
1381   }
1382   return FPM->run(F);
1383 }
1384
1385
1386 /// doInitialization - Run all of the initializers for the function passes.
1387 ///
1388 bool FunctionPassManager::doInitialization() {
1389   return FPM->doInitialization(*M);
1390 }
1391
1392 /// doFinalization - Run all of the finalizers for the function passes.
1393 ///
1394 bool FunctionPassManager::doFinalization() {
1395   return FPM->doFinalization(*M);
1396 }
1397
1398 //===----------------------------------------------------------------------===//
1399 // FunctionPassManagerImpl implementation
1400 //
1401 bool FunctionPassManagerImpl::doInitialization(Module &M) {
1402   bool Changed = false;
1403
1404   dumpArguments();
1405   dumpPasses();
1406
1407   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
1408     Changed |= getContainedManager(Index)->doInitialization(M);
1409
1410   return Changed;
1411 }
1412
1413 bool FunctionPassManagerImpl::doFinalization(Module &M) {
1414   bool Changed = false;
1415
1416   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
1417     Changed |= getContainedManager(Index)->doFinalization(M);
1418
1419   return Changed;
1420 }
1421
1422 /// cleanup - After running all passes, clean up pass manager cache.
1423 void FPPassManager::cleanup() {
1424  for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1425     FunctionPass *FP = getContainedPass(Index);
1426     AnalysisResolver *AR = FP->getResolver();
1427     assert(AR && "Analysis Resolver is not set");
1428     AR->clearAnalysisImpls();
1429  }
1430 }
1431
1432 void FunctionPassManagerImpl::releaseMemoryOnTheFly() {
1433   if (!wasRun)
1434     return;
1435   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index) {
1436     FPPassManager *FPPM = getContainedManager(Index);
1437     for (unsigned Index = 0; Index < FPPM->getNumContainedPasses(); ++Index) {
1438       FPPM->getContainedPass(Index)->releaseMemory();
1439     }
1440   }
1441   wasRun = false;
1442 }
1443
1444 // Execute all the passes managed by this top level manager.
1445 // Return true if any function is modified by a pass.
1446 bool FunctionPassManagerImpl::run(Function &F) {
1447   bool Changed = false;
1448   TimingInfo::createTheTimeInfo();
1449   createDebugInfoProbe();
1450
1451   initializeAllAnalysisInfo();
1452   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
1453     Changed |= getContainedManager(Index)->runOnFunction(F);
1454
1455   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
1456     getContainedManager(Index)->cleanup();
1457
1458   wasRun = true;
1459   return Changed;
1460 }
1461
1462 //===----------------------------------------------------------------------===//
1463 // FPPassManager implementation
1464
1465 char FPPassManager::ID = 0;
1466 /// Print passes managed by this manager
1467 void FPPassManager::dumpPassStructure(unsigned Offset) {
1468   llvm::dbgs() << std::string(Offset*2, ' ') << "FunctionPass Manager\n";
1469   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1470     FunctionPass *FP = getContainedPass(Index);
1471     FP->dumpPassStructure(Offset + 1);
1472     dumpLastUses(FP, Offset+1);
1473   }
1474 }
1475
1476
1477 /// Execute all of the passes scheduled for execution by invoking
1478 /// runOnFunction method.  Keep track of whether any of the passes modifies
1479 /// the function, and if so, return true.
1480 bool FPPassManager::runOnFunction(Function &F) {
1481   if (F.isDeclaration())
1482     return false;
1483
1484   bool Changed = false;
1485
1486   // Collect inherited analysis from Module level pass manager.
1487   populateInheritedAnalysis(TPM->activeStack);
1488
1489   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1490     FunctionPass *FP = getContainedPass(Index);
1491     bool LocalChanged = false;
1492
1493     dumpPassInfo(FP, EXECUTION_MSG, ON_FUNCTION_MSG, F.getName());
1494     dumpRequiredSet(FP);
1495
1496     initializeAnalysisImpl(FP);
1497     if (TheDebugProbe)
1498       TheDebugProbe->initialize(FP, F);
1499     {
1500       PassManagerPrettyStackEntry X(FP, F);
1501       TimeRegion PassTimer(getPassTimer(FP));
1502
1503       LocalChanged |= FP->runOnFunction(F);
1504     }
1505     if (TheDebugProbe)
1506       TheDebugProbe->finalize(FP, F);
1507
1508     Changed |= LocalChanged;
1509     if (LocalChanged)
1510       dumpPassInfo(FP, MODIFICATION_MSG, ON_FUNCTION_MSG, F.getName());
1511     dumpPreservedSet(FP);
1512
1513     verifyPreservedAnalysis(FP);
1514     removeNotPreservedAnalysis(FP);
1515     recordAvailableAnalysis(FP);
1516     removeDeadPasses(FP, F.getName(), ON_FUNCTION_MSG);
1517   }
1518   return Changed;
1519 }
1520
1521 bool FPPassManager::runOnModule(Module &M) {
1522   bool Changed = doInitialization(M);
1523
1524   for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
1525     runOnFunction(*I);
1526
1527   return doFinalization(M) || Changed;
1528 }
1529
1530 bool FPPassManager::doInitialization(Module &M) {
1531   bool Changed = false;
1532
1533   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index)
1534     Changed |= getContainedPass(Index)->doInitialization(M);
1535
1536   return Changed;
1537 }
1538
1539 bool FPPassManager::doFinalization(Module &M) {
1540   bool Changed = false;
1541
1542   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index)
1543     Changed |= getContainedPass(Index)->doFinalization(M);
1544
1545   return Changed;
1546 }
1547
1548 //===----------------------------------------------------------------------===//
1549 // MPPassManager implementation
1550
1551 /// Execute all of the passes scheduled for execution by invoking
1552 /// runOnModule method.  Keep track of whether any of the passes modifies
1553 /// the module, and if so, return true.
1554 bool
1555 MPPassManager::runOnModule(Module &M) {
1556   bool Changed = false;
1557
1558   // Initialize on-the-fly passes
1559   for (std::map<Pass *, FunctionPassManagerImpl *>::iterator
1560        I = OnTheFlyManagers.begin(), E = OnTheFlyManagers.end();
1561        I != E; ++I) {
1562     FunctionPassManagerImpl *FPP = I->second;
1563     Changed |= FPP->doInitialization(M);
1564   }
1565
1566   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1567     ModulePass *MP = getContainedPass(Index);
1568     bool LocalChanged = false;
1569
1570     dumpPassInfo(MP, EXECUTION_MSG, ON_MODULE_MSG, M.getModuleIdentifier());
1571     dumpRequiredSet(MP);
1572
1573     initializeAnalysisImpl(MP);
1574
1575     {
1576       PassManagerPrettyStackEntry X(MP, M);
1577       TimeRegion PassTimer(getPassTimer(MP));
1578
1579       LocalChanged |= MP->runOnModule(M);
1580     }
1581
1582     Changed |= LocalChanged;
1583     if (LocalChanged)
1584       dumpPassInfo(MP, MODIFICATION_MSG, ON_MODULE_MSG,
1585                    M.getModuleIdentifier());
1586     dumpPreservedSet(MP);
1587
1588     verifyPreservedAnalysis(MP);
1589     removeNotPreservedAnalysis(MP);
1590     recordAvailableAnalysis(MP);
1591     removeDeadPasses(MP, M.getModuleIdentifier(), ON_MODULE_MSG);
1592   }
1593
1594   // Finalize on-the-fly passes
1595   for (std::map<Pass *, FunctionPassManagerImpl *>::iterator
1596        I = OnTheFlyManagers.begin(), E = OnTheFlyManagers.end();
1597        I != E; ++I) {
1598     FunctionPassManagerImpl *FPP = I->second;
1599     // We don't know when is the last time an on-the-fly pass is run,
1600     // so we need to releaseMemory / finalize here
1601     FPP->releaseMemoryOnTheFly();
1602     Changed |= FPP->doFinalization(M);
1603   }
1604   return Changed;
1605 }
1606
1607 /// Add RequiredPass into list of lower level passes required by pass P.
1608 /// RequiredPass is run on the fly by Pass Manager when P requests it
1609 /// through getAnalysis interface.
1610 void MPPassManager::addLowerLevelRequiredPass(Pass *P, Pass *RequiredPass) {
1611   assert(P->getPotentialPassManagerType() == PMT_ModulePassManager &&
1612          "Unable to handle Pass that requires lower level Analysis pass");
1613   assert((P->getPotentialPassManagerType() <
1614           RequiredPass->getPotentialPassManagerType()) &&
1615          "Unable to handle Pass that requires lower level Analysis pass");
1616
1617   FunctionPassManagerImpl *FPP = OnTheFlyManagers[P];
1618   if (!FPP) {
1619     FPP = new FunctionPassManagerImpl(0);
1620     // FPP is the top level manager.
1621     FPP->setTopLevelManager(FPP);
1622
1623     OnTheFlyManagers[P] = FPP;
1624   }
1625   FPP->add(RequiredPass);
1626
1627   // Register P as the last user of RequiredPass.
1628   SmallVector<Pass *, 1> LU;
1629   LU.push_back(RequiredPass);
1630   FPP->setLastUser(LU,  P);
1631 }
1632
1633 /// Return function pass corresponding to PassInfo PI, that is
1634 /// required by module pass MP. Instantiate analysis pass, by using
1635 /// its runOnFunction() for function F.
1636 Pass* MPPassManager::getOnTheFlyPass(Pass *MP, AnalysisID PI, Function &F){
1637   FunctionPassManagerImpl *FPP = OnTheFlyManagers[MP];
1638   assert(FPP && "Unable to find on the fly pass");
1639
1640   FPP->releaseMemoryOnTheFly();
1641   FPP->run(F);
1642   return ((PMTopLevelManager*)FPP)->findAnalysisPass(PI);
1643 }
1644
1645
1646 //===----------------------------------------------------------------------===//
1647 // PassManagerImpl implementation
1648 //
1649 /// run - Execute all of the passes scheduled for execution.  Keep track of
1650 /// whether any of the passes modifies the module, and if so, return true.
1651 bool PassManagerImpl::run(Module &M) {
1652   bool Changed = false;
1653   TimingInfo::createTheTimeInfo();
1654   createDebugInfoProbe();
1655
1656   dumpArguments();
1657   dumpPasses();
1658
1659   initializeAllAnalysisInfo();
1660   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
1661     Changed |= getContainedManager(Index)->runOnModule(M);
1662   return Changed;
1663 }
1664
1665 //===----------------------------------------------------------------------===//
1666 // PassManager implementation
1667
1668 /// Create new pass manager
1669 PassManager::PassManager() {
1670   PM = new PassManagerImpl(0);
1671   // PM is the top level manager
1672   PM->setTopLevelManager(PM);
1673 }
1674
1675 PassManager::~PassManager() {
1676   delete PM;
1677 }
1678
1679 /// addImpl - Add a pass to the queue of passes to run, without
1680 /// checking whether to add a printer pass.
1681 void PassManager::addImpl(Pass *P) {
1682   PM->add(P);
1683 }
1684
1685 /// add - Add a pass to the queue of passes to run.  This passes ownership of
1686 /// the Pass to the PassManager.  When the PassManager is destroyed, the pass
1687 /// will be destroyed as well, so there is no need to delete the pass.  This
1688 /// implies that all passes MUST be allocated with 'new'.
1689 void PassManager::add(Pass *P) {
1690   const void* PassID = P->getPassID();
1691   if (ShouldPrintBeforePass(PassID))
1692     addImpl(P->createPrinterPass(dbgs(), std::string("*** IR Dump Before ")
1693                                  + P->getPassName() + " ***"));
1694
1695   addImpl(P);
1696
1697   if (ShouldPrintAfterPass(PassID))
1698     addImpl(P->createPrinterPass(dbgs(), std::string("*** IR Dump After ")
1699                                  + P->getPassName() + " ***"));
1700 }
1701
1702 /// run - Execute all of the passes scheduled for execution.  Keep track of
1703 /// whether any of the passes modifies the module, and if so, return true.
1704 bool PassManager::run(Module &M) {
1705   return PM->run(M);
1706 }
1707
1708 //===----------------------------------------------------------------------===//
1709 // TimingInfo Class - This class is used to calculate information about the
1710 // amount of time each pass takes to execute.  This only happens with
1711 // -time-passes is enabled on the command line.
1712 //
1713 bool llvm::TimePassesIsEnabled = false;
1714 static cl::opt<bool,true>
1715 EnableTiming("time-passes", cl::location(TimePassesIsEnabled),
1716             cl::desc("Time each pass, printing elapsed time for each on exit"));
1717
1718 // createTheTimeInfo - This method either initializes the TheTimeInfo pointer to
1719 // a non null value (if the -time-passes option is enabled) or it leaves it
1720 // null.  It may be called multiple times.
1721 void TimingInfo::createTheTimeInfo() {
1722   if (!TimePassesIsEnabled || TheTimeInfo) return;
1723
1724   // Constructed the first time this is called, iff -time-passes is enabled.
1725   // This guarantees that the object will be constructed before static globals,
1726   // thus it will be destroyed before them.
1727   static ManagedStatic<TimingInfo> TTI;
1728   TheTimeInfo = &*TTI;
1729 }
1730
1731 /// If TimingInfo is enabled then start pass timer.
1732 Timer *llvm::getPassTimer(Pass *P) {
1733   if (TheTimeInfo)
1734     return TheTimeInfo->getPassTimer(P);
1735   return 0;
1736 }
1737
1738 //===----------------------------------------------------------------------===//
1739 // PMStack implementation
1740 //
1741
1742 // Pop Pass Manager from the stack and clear its analysis info.
1743 void PMStack::pop() {
1744
1745   PMDataManager *Top = this->top();
1746   Top->initializeAnalysisInfo();
1747
1748   S.pop_back();
1749 }
1750
1751 // Push PM on the stack and set its top level manager.
1752 void PMStack::push(PMDataManager *PM) {
1753   assert(PM && "Unable to push. Pass Manager expected");
1754
1755   if (!this->empty()) {
1756     PMTopLevelManager *TPM = this->top()->getTopLevelManager();
1757
1758     assert(TPM && "Unable to find top level manager");
1759     TPM->addIndirectPassManager(PM);
1760     PM->setTopLevelManager(TPM);
1761   }
1762
1763   S.push_back(PM);
1764 }
1765
1766 // Dump content of the pass manager stack.
1767 void PMStack::dump() const {
1768   for (std::vector<PMDataManager *>::const_iterator I = S.begin(),
1769          E = S.end(); I != E; ++I)
1770     printf("%s ", (*I)->getAsPass()->getPassName());
1771
1772   if (!S.empty())
1773     printf("\n");
1774 }
1775
1776 /// Find appropriate Module Pass Manager in the PM Stack and
1777 /// add self into that manager.
1778 void ModulePass::assignPassManager(PMStack &PMS,
1779                                    PassManagerType PreferredType) {
1780   // Find Module Pass Manager
1781   while (!PMS.empty()) {
1782     PassManagerType TopPMType = PMS.top()->getPassManagerType();
1783     if (TopPMType == PreferredType)
1784       break; // We found desired pass manager
1785     else if (TopPMType > PMT_ModulePassManager)
1786       PMS.pop();    // Pop children pass managers
1787     else
1788       break;
1789   }
1790   assert(!PMS.empty() && "Unable to find appropriate Pass Manager");
1791   PMS.top()->add(this);
1792 }
1793
1794 /// Find appropriate Function Pass Manager or Call Graph Pass Manager
1795 /// in the PM Stack and add self into that manager.
1796 void FunctionPass::assignPassManager(PMStack &PMS,
1797                                      PassManagerType PreferredType) {
1798
1799   // Find Module Pass Manager
1800   while (!PMS.empty()) {
1801     if (PMS.top()->getPassManagerType() > PMT_FunctionPassManager)
1802       PMS.pop();
1803     else
1804       break;
1805   }
1806
1807   // Create new Function Pass Manager if needed.
1808   FPPassManager *FPP;
1809   if (PMS.top()->getPassManagerType() == PMT_FunctionPassManager) {
1810     FPP = (FPPassManager *)PMS.top();
1811   } else {
1812     assert(!PMS.empty() && "Unable to create Function Pass Manager");
1813     PMDataManager *PMD = PMS.top();
1814
1815     // [1] Create new Function Pass Manager
1816     FPP = new FPPassManager(PMD->getDepth() + 1);
1817     FPP->populateInheritedAnalysis(PMS);
1818
1819     // [2] Set up new manager's top level manager
1820     PMTopLevelManager *TPM = PMD->getTopLevelManager();
1821     TPM->addIndirectPassManager(FPP);
1822
1823     // [3] Assign manager to manage this new manager. This may create
1824     // and push new managers into PMS
1825     FPP->assignPassManager(PMS, PMD->getPassManagerType());
1826
1827     // [4] Push new manager into PMS
1828     PMS.push(FPP);
1829   }
1830
1831   // Assign FPP as the manager of this pass.
1832   FPP->add(this);
1833 }
1834
1835 /// Find appropriate Basic Pass Manager or Call Graph Pass Manager
1836 /// in the PM Stack and add self into that manager.
1837 void BasicBlockPass::assignPassManager(PMStack &PMS,
1838                                        PassManagerType PreferredType) {
1839   BBPassManager *BBP;
1840
1841   // Basic Pass Manager is a leaf pass manager. It does not handle
1842   // any other pass manager.
1843   if (!PMS.empty() &&
1844       PMS.top()->getPassManagerType() == PMT_BasicBlockPassManager) {
1845     BBP = (BBPassManager *)PMS.top();
1846   } else {
1847     // If leaf manager is not Basic Block Pass manager then create new
1848     // basic Block Pass manager.
1849     assert(!PMS.empty() && "Unable to create BasicBlock Pass Manager");
1850     PMDataManager *PMD = PMS.top();
1851
1852     // [1] Create new Basic Block Manager
1853     BBP = new BBPassManager(PMD->getDepth() + 1);
1854
1855     // [2] Set up new manager's top level manager
1856     // Basic Block Pass Manager does not live by itself
1857     PMTopLevelManager *TPM = PMD->getTopLevelManager();
1858     TPM->addIndirectPassManager(BBP);
1859
1860     // [3] Assign manager to manage this new manager. This may create
1861     // and push new managers into PMS
1862     BBP->assignPassManager(PMS, PreferredType);
1863
1864     // [4] Push new manager into PMS
1865     PMS.push(BBP);
1866   }
1867
1868   // Assign BBP as the manager of this pass.
1869   BBP->add(this);
1870 }
1871
1872 PassManagerBase::~PassManagerBase() {}