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         assert(PI && "Expected required passes to be initialized");
 636         AnalysisPass = PI->createPass();
 637         if (P->getPotentialPassManagerType () ==
 638             AnalysisPass->getPotentialPassManagerType())
 639           // Schedule analysis pass that is managed by the same pass manager.
 640           schedulePass(AnalysisPass);
 641         else if (P->getPotentialPassManagerType () >
 642                  AnalysisPass->getPotentialPassManagerType()) {
 643           // Schedule analysis pass that is managed by a new manager.
 644           schedulePass(AnalysisPass);
 645           // Recheck analysis passes to ensure that required analyses that
 646           // are already checked are still available.
 647           checkAnalysis = true;
 648         }
 649         else
 650           // Do not schedule this analysis. Lower level analsyis
 651           // passes are run on the fly.
 652           delete AnalysisPass;
 653       }
 654     }
 655   }
 656
 657   // Now all required passes are available.
 658   addTopLevelPass(P);
 659 }
 660
 661 /// Find the pass that implements Analysis AID. Search immutable
 662 /// passes and all pass managers. If desired pass is not found
 663 /// then return NULL.
 664 Pass *PMTopLevelManager::findAnalysisPass(AnalysisID AID) {
 665
 666   // Check pass managers
 667   for (SmallVectorImpl<PMDataManager *>::iterator I = PassManagers.begin(),
 668          E = PassManagers.end(); I != E; ++I)
 669     if (Pass *P = (*I)->findAnalysisPass(AID, false))
 670       return P;
 671
 672   // Check other pass managers
 673   for (SmallVectorImpl<PMDataManager *>::iterator
 674          I = IndirectPassManagers.begin(),
 675          E = IndirectPassManagers.end(); I != E; ++I)
 676     if (Pass *P = (*I)->findAnalysisPass(AID, false))
 677       return P;
 678
 679   // Check the immutable passes. Iterate in reverse order so that we find
 680   // the most recently registered passes first.
 681   for (SmallVector<ImmutablePass *, 8>::reverse_iterator I =
 682        ImmutablePasses.rbegin(), E = ImmutablePasses.rend(); I != E; ++I) {
 683     AnalysisID PI = (*I)->getPassID();
 684     if (PI == AID)
 685       return *I;
 686
 687     // If Pass not found then check the interfaces implemented by Immutable Pass
 688     const PassInfo *PassInf =
 689       PassRegistry::getPassRegistry()->getPassInfo(PI);
 690     assert(PassInf && "Expected all immutable passes to be initialized");
 691     const std::vector<const PassInfo*> &ImmPI =
 692       PassInf->getInterfacesImplemented();
 693     for (std::vector<const PassInfo*>::const_iterator II = ImmPI.begin(),
 694          EE = ImmPI.end(); II != EE; ++II) {
 695       if ((*II)->getTypeInfo() == AID)
 696         return *I;
 697     }
 698   }
 699
 700   return 0;
 701 }
 702
 703 // Print passes managed by this top level manager.
 704 void PMTopLevelManager::dumpPasses() const {
 705
 706   if (PassDebugging < Structure)
 707     return;
 708
 709   // Print out the immutable passes
 710   for (unsigned i = 0, e = ImmutablePasses.size(); i != e; ++i) {
 711     ImmutablePasses[i]->dumpPassStructure(0);
 712   }
 713
 714   // Every class that derives from PMDataManager also derives from Pass
 715   // (sometimes indirectly), but there's no inheritance relationship
 716   // between PMDataManager and Pass, so we have to getAsPass to get
 717   // from a PMDataManager* to a Pass*.
 718   for (SmallVector<PMDataManager *, 8>::const_iterator I = PassManagers.begin(),
 719          E = PassManagers.end(); I != E; ++I)
 720     (*I)->getAsPass()->dumpPassStructure(1);
 721 }
 722
 723 void PMTopLevelManager::dumpArguments() const {
 724
 725   if (PassDebugging < Arguments)
 726     return;
 727
 728   dbgs() << "Pass Arguments: ";
 729   for (SmallVector<ImmutablePass *, 8>::const_iterator I =
 730        ImmutablePasses.begin(), E = ImmutablePasses.end(); I != E; ++I)
 731     if (const PassInfo *PI =
 732         PassRegistry::getPassRegistry()->getPassInfo((*I)->getPassID())) {
 733       assert(PI && "Expected all immutable passes to be initialized");
 734       if (!PI->isAnalysisGroup())
 735         dbgs() << " -" << PI->getPassArgument();
 736     }
 737   for (SmallVector<PMDataManager *, 8>::const_iterator I = PassManagers.begin(),
 738          E = PassManagers.end(); I != E; ++I)
 739     (*I)->dumpPassArguments();
 740   dbgs() << "\n";
 741 }
 742
 743 void PMTopLevelManager::initializeAllAnalysisInfo() {
 744   for (SmallVectorImpl<PMDataManager *>::iterator I = PassManagers.begin(),
 745          E = PassManagers.end(); I != E; ++I)
 746     (*I)->initializeAnalysisInfo();
 747
 748   // Initailize other pass managers
 749   for (SmallVectorImpl<PMDataManager *>::iterator
 750        I = IndirectPassManagers.begin(), E = IndirectPassManagers.end();
 751        I != E; ++I)
 752     (*I)->initializeAnalysisInfo();
 753
 754   for (DenseMap<Pass *, Pass *>::iterator DMI = LastUser.begin(),
 755         DME = LastUser.end(); DMI != DME; ++DMI) {
 756     DenseMap<Pass *, SmallPtrSet<Pass *, 8> >::iterator InvDMI =
 757       InversedLastUser.find(DMI->second);
 758     if (InvDMI != InversedLastUser.end()) {
 759       SmallPtrSet<Pass *, 8> &L = InvDMI->second;
 760       L.insert(DMI->first);
 761     } else {
 762       SmallPtrSet<Pass *, 8> L; L.insert(DMI->first);
 763       InversedLastUser[DMI->second] = L;
 764     }
 765   }
 766 }
 767
 768 /// Destructor
 769 PMTopLevelManager::~PMTopLevelManager() {
 770   for (SmallVectorImpl<PMDataManager *>::iterator I = PassManagers.begin(),
 771          E = PassManagers.end(); I != E; ++I)
 772     delete *I;
 773
 774   for (SmallVectorImpl<ImmutablePass *>::iterator
 775          I = ImmutablePasses.begin(), E = ImmutablePasses.end(); I != E; ++I)
 776     delete *I;
 777
 778   for (DenseMap<Pass *, AnalysisUsage *>::iterator DMI = AnUsageMap.begin(),
 779          DME = AnUsageMap.end(); DMI != DME; ++DMI)
 780     delete DMI->second;
 781 }
 782
 783 //===----------------------------------------------------------------------===//
 784 // PMDataManager implementation
 785
 786 /// Augement AvailableAnalysis by adding analysis made available by pass P.
 787 void PMDataManager::recordAvailableAnalysis(Pass *P) {
 788   AnalysisID PI = P->getPassID();
 789
 790   AvailableAnalysis[PI] = P;
 791
 792   assert(!AvailableAnalysis.empty());
 793
 794   // This pass is the current implementation of all of the interfaces it
 795   // implements as well.
 796   const PassInfo *PInf = PassRegistry::getPassRegistry()->getPassInfo(PI);
 797   if (PInf == 0) return;
 798   const std::vector<const PassInfo*> &II = PInf->getInterfacesImplemented();
 799   for (unsigned i = 0, e = II.size(); i != e; ++i)
 800     AvailableAnalysis[II[i]->getTypeInfo()] = P;
 801 }
 802
 803 // Return true if P preserves high level analysis used by other
 804 // passes managed by this manager
 805 bool PMDataManager::preserveHigherLevelAnalysis(Pass *P) {
 806   AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
 807   if (AnUsage->getPreservesAll())
 808     return true;
 809
 810   const AnalysisUsage::VectorType &PreservedSet = AnUsage->getPreservedSet();
 811   for (SmallVectorImpl<Pass *>::iterator I = HigherLevelAnalysis.begin(),
 812          E = HigherLevelAnalysis.end(); I  != E; ++I) {
 813     Pass *P1 = *I;
 814     if (P1->getAsImmutablePass() == 0 &&
 815         std::find(PreservedSet.begin(), PreservedSet.end(),
 816                   P1->getPassID()) ==
 817            PreservedSet.end())
 818       return false;
 819   }
 820
 821   return true;
 822 }
 823
 824 /// verifyPreservedAnalysis -- Verify analysis preserved by pass P.
 825 void PMDataManager::verifyPreservedAnalysis(Pass *P) {
 826   // Don't do this unless assertions are enabled.
 827 #ifdef NDEBUG
 828   return;
 829 #endif
 830   AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
 831   const AnalysisUsage::VectorType &PreservedSet = AnUsage->getPreservedSet();
 832
 833   // Verify preserved analysis
 834   for (AnalysisUsage::VectorType::const_iterator I = PreservedSet.begin(),
 835          E = PreservedSet.end(); I != E; ++I) {
 836     AnalysisID AID = *I;
 837     if (Pass *AP = findAnalysisPass(AID, true)) {
 838       TimeRegion PassTimer(getPassTimer(AP));
 839       AP->verifyAnalysis();
 840     }
 841   }
 842 }
 843
 844 /// Remove Analysis not preserved by Pass P
 845 void PMDataManager::removeNotPreservedAnalysis(Pass *P) {
 846   AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
 847   if (AnUsage->getPreservesAll())
 848     return;
 849
 850   const AnalysisUsage::VectorType &PreservedSet = AnUsage->getPreservedSet();
 851   for (std::map<AnalysisID, Pass*>::iterator I = AvailableAnalysis.begin(),
 852          E = AvailableAnalysis.end(); I != E; ) {
 853     std::map<AnalysisID, Pass*>::iterator Info = I++;
 854     if (Info->second->getAsImmutablePass() == 0 &&
 855         std::find(PreservedSet.begin(), PreservedSet.end(), Info->first) ==
 856         PreservedSet.end()) {
 857       // Remove this analysis
 858       if (PassDebugging >= Details) {
 859         Pass *S = Info->second;
 860         dbgs() << " -- '" <<  P->getPassName() << "' is not preserving '";
 861         dbgs() << S->getPassName() << "'\n";
 862       }
 863       AvailableAnalysis.erase(Info);
 864     }
 865   }
 866
 867   // Check inherited analysis also. If P is not preserving analysis
 868   // provided by parent manager then remove it here.
 869   for (unsigned Index = 0; Index < PMT_Last; ++Index) {
 870
 871     if (!InheritedAnalysis[Index])
 872       continue;
 873
 874     for (std::map<AnalysisID, Pass*>::iterator
 875            I = InheritedAnalysis[Index]->begin(),
 876            E = InheritedAnalysis[Index]->end(); I != E; ) {
 877       std::map<AnalysisID, Pass *>::iterator Info = I++;
 878       if (Info->second->getAsImmutablePass() == 0 &&
 879           std::find(PreservedSet.begin(), PreservedSet.end(), Info->first) ==
 880              PreservedSet.end()) {
 881         // Remove this analysis
 882         if (PassDebugging >= Details) {
 883           Pass *S = Info->second;
 884           dbgs() << " -- '" <<  P->getPassName() << "' is not preserving '";
 885           dbgs() << S->getPassName() << "'\n";
 886         }
 887         InheritedAnalysis[Index]->erase(Info);
 888       }
 889     }
 890   }
 891 }
 892
 893 /// Remove analysis passes that are not used any longer
 894 void PMDataManager::removeDeadPasses(Pass *P, StringRef Msg,
 895                                      enum PassDebuggingString DBG_STR) {
 896
 897   SmallVector<Pass *, 12> DeadPasses;
 898
 899   // If this is a on the fly manager then it does not have TPM.
 900   if (!TPM)
 901     return;
 902
 903   TPM->collectLastUses(DeadPasses, P);
 904
 905   if (PassDebugging >= Details && !DeadPasses.empty()) {
 906     dbgs() << " -*- '" <<  P->getPassName();
 907     dbgs() << "' is the last user of following pass instances.";
 908     dbgs() << " Free these instances\n";
 909   }
 910
 911   for (SmallVectorImpl<Pass *>::iterator I = DeadPasses.begin(),
 912          E = DeadPasses.end(); I != E; ++I)
 913     freePass(*I, Msg, DBG_STR);
 914 }
 915
 916 void PMDataManager::freePass(Pass *P, StringRef Msg,
 917                              enum PassDebuggingString DBG_STR) {
 918   dumpPassInfo(P, FREEING_MSG, DBG_STR, Msg);
 919
 920   {
 921     // If the pass crashes releasing memory, remember this.
 922     PassManagerPrettyStackEntry X(P);
 923     TimeRegion PassTimer(getPassTimer(P));
 924
 925     P->releaseMemory();
 926   }
 927
 928   AnalysisID PI = P->getPassID();
 929   if (const PassInfo *PInf = PassRegistry::getPassRegistry()->getPassInfo(PI)) {
 930     // Remove the pass itself (if it is not already removed).
 931     AvailableAnalysis.erase(PI);
 932
 933     // Remove all interfaces this pass implements, for which it is also
 934     // listed as the available implementation.
 935     const std::vector<const PassInfo*> &II = PInf->getInterfacesImplemented();
 936     for (unsigned i = 0, e = II.size(); i != e; ++i) {
 937       std::map<AnalysisID, Pass*>::iterator Pos =
 938         AvailableAnalysis.find(II[i]->getTypeInfo());
 939       if (Pos != AvailableAnalysis.end() && Pos->second == P)
 940         AvailableAnalysis.erase(Pos);
 941     }
 942   }
 943 }
 944
 945 /// Add pass P into the PassVector. Update
 946 /// AvailableAnalysis appropriately if ProcessAnalysis is true.
 947 void PMDataManager::add(Pass *P, bool ProcessAnalysis) {
 948   // This manager is going to manage pass P. Set up analysis resolver
 949   // to connect them.
 950   AnalysisResolver *AR = new AnalysisResolver(*this);
 951   P->setResolver(AR);
 952
 953   // If a FunctionPass F is the last user of ModulePass info M
 954   // then the F's manager, not F, records itself as a last user of M.
 955   SmallVector<Pass *, 12> TransferLastUses;
 956
 957   if (!ProcessAnalysis) {
 958     // Add pass
 959     PassVector.push_back(P);
 960     return;
 961   }
 962
 963   // At the moment, this pass is the last user of all required passes.
 964   SmallVector<Pass *, 12> LastUses;
 965   SmallVector<Pass *, 8> RequiredPasses;
 966   SmallVector<AnalysisID, 8> ReqAnalysisNotAvailable;
 967
 968   unsigned PDepth = this->getDepth();
 969
 970   collectRequiredAnalysis(RequiredPasses,
 971                           ReqAnalysisNotAvailable, P);
 972   for (SmallVectorImpl<Pass *>::iterator I = RequiredPasses.begin(),
 973          E = RequiredPasses.end(); I != E; ++I) {
 974     Pass *PRequired = *I;
 975     unsigned RDepth = 0;
 976
 977     assert(PRequired->getResolver() && "Analysis Resolver is not set");
 978     PMDataManager &DM = PRequired->getResolver()->getPMDataManager();
 979     RDepth = DM.getDepth();
 980
 981     if (PDepth == RDepth)
 982       LastUses.push_back(PRequired);
 983     else if (PDepth > RDepth) {
 984       // Let the parent claim responsibility of last use
 985       TransferLastUses.push_back(PRequired);
 986       // Keep track of higher level analysis used by this manager.
 987       HigherLevelAnalysis.push_back(PRequired);
 988     } else
 989       llvm_unreachable("Unable to accommodate Required Pass");
 990   }
 991
 992   // Set P as P's last user until someone starts using P.
 993   // However, if P is a Pass Manager then it does not need
 994   // to record its last user.
 995   if (P->getAsPMDataManager() == 0)
 996     LastUses.push_back(P);
 997   TPM->setLastUser(LastUses, P);
 998
 999   if (!TransferLastUses.empty()) {
1000     Pass *My_PM = getAsPass();
1001     TPM->setLastUser(TransferLastUses, My_PM);
1002     TransferLastUses.clear();
1003   }
1004
1005   // Now, take care of required analyses that are not available.
1006   for (SmallVectorImpl<AnalysisID>::iterator
1007          I = ReqAnalysisNotAvailable.begin(),
1008          E = ReqAnalysisNotAvailable.end() ;I != E; ++I) {
1009     const PassInfo *PI = PassRegistry::getPassRegistry()->getPassInfo(*I);
1010     Pass *AnalysisPass = PI->createPass();
1011     this->addLowerLevelRequiredPass(P, AnalysisPass);
1012   }
1013
1014   // Take a note of analysis required and made available by this pass.
1015   // Remove the analysis not preserved by this pass
1016   removeNotPreservedAnalysis(P);
1017   recordAvailableAnalysis(P);
1018
1019   // Add pass
1020   PassVector.push_back(P);
1021 }
1022
1023
1024 /// Populate RP with analysis pass that are required by
1025 /// pass P and are available. Populate RP_NotAvail with analysis
1026 /// pass that are required by pass P but are not available.
1027 void PMDataManager::collectRequiredAnalysis(SmallVectorImpl<Pass *> &RP,
1028                                        SmallVectorImpl<AnalysisID> &RP_NotAvail,
1029                                             Pass *P) {
1030   AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
1031   const AnalysisUsage::VectorType &RequiredSet = AnUsage->getRequiredSet();
1032   for (AnalysisUsage::VectorType::const_iterator
1033          I = RequiredSet.begin(), E = RequiredSet.end(); I != E; ++I) {
1034     if (Pass *AnalysisPass = findAnalysisPass(*I, true))
1035       RP.push_back(AnalysisPass);
1036     else
1037       RP_NotAvail.push_back(*I);
1038   }
1039
1040   const AnalysisUsage::VectorType &IDs = AnUsage->getRequiredTransitiveSet();
1041   for (AnalysisUsage::VectorType::const_iterator I = IDs.begin(),
1042          E = IDs.end(); I != E; ++I) {
1043     if (Pass *AnalysisPass = findAnalysisPass(*I, true))
1044       RP.push_back(AnalysisPass);
1045     else
1046       RP_NotAvail.push_back(*I);
1047   }
1048 }
1049
1050 // All Required analyses should be available to the pass as it runs!  Here
1051 // we fill in the AnalysisImpls member of the pass so that it can
1052 // successfully use the getAnalysis() method to retrieve the
1053 // implementations it needs.
1054 //
1055 void PMDataManager::initializeAnalysisImpl(Pass *P) {
1056   AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
1057
1058   for (AnalysisUsage::VectorType::const_iterator
1059          I = AnUsage->getRequiredSet().begin(),
1060          E = AnUsage->getRequiredSet().end(); I != E; ++I) {
1061     Pass *Impl = findAnalysisPass(*I, true);
1062     if (Impl == 0)
1063       // This may be analysis pass that is initialized on the fly.
1064       // If that is not the case then it will raise an assert when it is used.
1065       continue;
1066     AnalysisResolver *AR = P->getResolver();
1067     assert(AR && "Analysis Resolver is not set");
1068     AR->addAnalysisImplsPair(*I, Impl);
1069   }
1070 }
1071
1072 /// Find the pass that implements Analysis AID. If desired pass is not found
1073 /// then return NULL.
1074 Pass *PMDataManager::findAnalysisPass(AnalysisID AID, bool SearchParent) {
1075
1076   // Check if AvailableAnalysis map has one entry.
1077   std::map<AnalysisID, Pass*>::const_iterator I =  AvailableAnalysis.find(AID);
1078
1079   if (I != AvailableAnalysis.end())
1080     return I->second;
1081
1082   // Search Parents through TopLevelManager
1083   if (SearchParent)
1084     return TPM->findAnalysisPass(AID);
1085
1086   return NULL;
1087 }
1088
1089 // Print list of passes that are last used by P.
1090 void PMDataManager::dumpLastUses(Pass *P, unsigned Offset) const{
1091
1092   SmallVector<Pass *, 12> LUses;
1093
1094   // If this is a on the fly manager then it does not have TPM.
1095   if (!TPM)
1096     return;
1097
1098   TPM->collectLastUses(LUses, P);
1099
1100   for (SmallVectorImpl<Pass *>::iterator I = LUses.begin(),
1101          E = LUses.end(); I != E; ++I) {
1102     llvm::dbgs() << "--" << std::string(Offset*2, ' ');
1103     (*I)->dumpPassStructure(0);
1104   }
1105 }
1106
1107 void PMDataManager::dumpPassArguments() const {
1108   for (SmallVectorImpl<Pass *>::const_iterator I = PassVector.begin(),
1109         E = PassVector.end(); I != E; ++I) {
1110     if (PMDataManager *PMD = (*I)->getAsPMDataManager())
1111       PMD->dumpPassArguments();
1112     else
1113       if (const PassInfo *PI =
1114             PassRegistry::getPassRegistry()->getPassInfo((*I)->getPassID()))
1115         if (!PI->isAnalysisGroup())
1116           dbgs() << " -" << PI->getPassArgument();
1117   }
1118 }
1119
1120 void PMDataManager::dumpPassInfo(Pass *P, enum PassDebuggingString S1,
1121                                  enum PassDebuggingString S2,
1122                                  StringRef Msg) {
1123   if (PassDebugging < Executions)
1124     return;
1125   dbgs() << (void*)this << std::string(getDepth()*2+1, ' ');
1126   switch (S1) {
1127   case EXECUTION_MSG:
1128     dbgs() << "Executing Pass '" << P->getPassName();
1129     break;
1130   case MODIFICATION_MSG:
1131     dbgs() << "Made Modification '" << P->getPassName();
1132     break;
1133   case FREEING_MSG:
1134     dbgs() << " Freeing Pass '" << P->getPassName();
1135     break;
1136   default:
1137     break;
1138   }
1139   switch (S2) {
1140   case ON_BASICBLOCK_MSG:
1141     dbgs() << "' on BasicBlock '" << Msg << "'...\n";
1142     break;
1143   case ON_FUNCTION_MSG:
1144     dbgs() << "' on Function '" << Msg << "'...\n";
1145     break;
1146   case ON_MODULE_MSG:
1147     dbgs() << "' on Module '"  << Msg << "'...\n";
1148     break;
1149   case ON_REGION_MSG:
1150     dbgs() << "' on Region '"  << Msg << "'...\n";
1151     break;
1152   case ON_LOOP_MSG:
1153     dbgs() << "' on Loop '" << Msg << "'...\n";
1154     break;
1155   case ON_CG_MSG:
1156     dbgs() << "' on Call Graph Nodes '" << Msg << "'...\n";
1157     break;
1158   default:
1159     break;
1160   }
1161 }
1162
1163 void PMDataManager::dumpRequiredSet(const Pass *P) const {
1164   if (PassDebugging < Details)
1165     return;
1166
1167   AnalysisUsage analysisUsage;
1168   P->getAnalysisUsage(analysisUsage);
1169   dumpAnalysisUsage("Required", P, analysisUsage.getRequiredSet());
1170 }
1171
1172 void PMDataManager::dumpPreservedSet(const Pass *P) const {
1173   if (PassDebugging < Details)
1174     return;
1175
1176   AnalysisUsage analysisUsage;
1177   P->getAnalysisUsage(analysisUsage);
1178   dumpAnalysisUsage("Preserved", P, analysisUsage.getPreservedSet());
1179 }
1180
1181 void PMDataManager::dumpAnalysisUsage(StringRef Msg, const Pass *P,
1182                                    const AnalysisUsage::VectorType &Set) const {
1183   assert(PassDebugging >= Details);
1184   if (Set.empty())
1185     return;
1186   dbgs() << (void*)P << std::string(getDepth()*2+3, ' ') << Msg << " Analyses:";
1187   for (unsigned i = 0; i != Set.size(); ++i) {
1188     if (i) dbgs() << ',';
1189     const PassInfo *PInf = PassRegistry::getPassRegistry()->getPassInfo(Set[i]);
1190     if (!PInf) {
1191       // Some preserved passes, such as AliasAnalysis, may not be initialized by
1192       // all drivers.
1193       dbgs() << " Uninitialized Pass";
1194       continue;
1195     }
1196     dbgs() << ' ' << PInf->getPassName();
1197   }
1198   dbgs() << '\n';
1199 }
1200
1201 /// Add RequiredPass into list of lower level passes required by pass P.
1202 /// RequiredPass is run on the fly by Pass Manager when P requests it
1203 /// through getAnalysis interface.
1204 /// This should be handled by specific pass manager.
1205 void PMDataManager::addLowerLevelRequiredPass(Pass *P, Pass *RequiredPass) {
1206   if (TPM) {
1207     TPM->dumpArguments();
1208     TPM->dumpPasses();
1209   }
1210
1211   // Module Level pass may required Function Level analysis info
1212   // (e.g. dominator info). Pass manager uses on the fly function pass manager
1213   // to provide this on demand. In that case, in Pass manager terminology,
1214   // module level pass is requiring lower level analysis info managed by
1215   // lower level pass manager.
1216
1217   // When Pass manager is not able to order required analysis info, Pass manager
1218   // checks whether any lower level manager will be able to provide this
1219   // analysis info on demand or not.
1220 #ifndef NDEBUG
1221   dbgs() << "Unable to schedule '" << RequiredPass->getPassName();
1222   dbgs() << "' required by '" << P->getPassName() << "'\n";
1223 #endif
1224   llvm_unreachable("Unable to schedule pass");
1225 }
1226
1227 Pass *PMDataManager::getOnTheFlyPass(Pass *P, AnalysisID PI, Function &F) {
1228   assert(0 && "Unable to find on the fly pass");
1229   return NULL;
1230 }
1231
1232 // Destructor
1233 PMDataManager::~PMDataManager() {
1234   for (SmallVectorImpl<Pass *>::iterator I = PassVector.begin(),
1235          E = PassVector.end(); I != E; ++I)
1236     delete *I;
1237 }
1238
1239 //===----------------------------------------------------------------------===//
1240 // NOTE: Is this the right place to define this method ?
1241 // getAnalysisIfAvailable - Return analysis result or null if it doesn't exist.
1242 Pass *AnalysisResolver::getAnalysisIfAvailable(AnalysisID ID, bool dir) const {
1243   return PM.findAnalysisPass(ID, dir);
1244 }
1245
1246 Pass *AnalysisResolver::findImplPass(Pass *P, AnalysisID AnalysisPI,
1247                                      Function &F) {
1248   return PM.getOnTheFlyPass(P, AnalysisPI, F);
1249 }
1250
1251 //===----------------------------------------------------------------------===//
1252 // BBPassManager implementation
1253
1254 /// Execute all of the passes scheduled for execution by invoking
1255 /// runOnBasicBlock method.  Keep track of whether any of the passes modifies
1256 /// the function, and if so, return true.
1257 bool BBPassManager::runOnFunction(Function &F) {
1258   if (F.isDeclaration())
1259     return false;
1260
1261   bool Changed = doInitialization(F);
1262
1263   for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
1264     for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1265       BasicBlockPass *BP = getContainedPass(Index);
1266       bool LocalChanged = false;
1267
1268       dumpPassInfo(BP, EXECUTION_MSG, ON_BASICBLOCK_MSG, I->getName());
1269       dumpRequiredSet(BP);
1270
1271       initializeAnalysisImpl(BP);
1272
1273       {
1274         // If the pass crashes, remember this.
1275         PassManagerPrettyStackEntry X(BP, *I);
1276         TimeRegion PassTimer(getPassTimer(BP));
1277
1278         LocalChanged |= BP->runOnBasicBlock(*I);
1279       }
1280
1281       Changed |= LocalChanged;
1282       if (LocalChanged)
1283         dumpPassInfo(BP, MODIFICATION_MSG, ON_BASICBLOCK_MSG,
1284                      I->getName());
1285       dumpPreservedSet(BP);
1286
1287       verifyPreservedAnalysis(BP);
1288       removeNotPreservedAnalysis(BP);
1289       recordAvailableAnalysis(BP);
1290       removeDeadPasses(BP, I->getName(), ON_BASICBLOCK_MSG);
1291     }
1292
1293   return doFinalization(F) || Changed;
1294 }
1295
1296 // Implement doInitialization and doFinalization
1297 bool BBPassManager::doInitialization(Module &M) {
1298   bool Changed = false;
1299
1300   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index)
1301     Changed |= getContainedPass(Index)->doInitialization(M);
1302
1303   return Changed;
1304 }
1305
1306 bool BBPassManager::doFinalization(Module &M) {
1307   bool Changed = false;
1308
1309   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index)
1310     Changed |= getContainedPass(Index)->doFinalization(M);
1311
1312   return Changed;
1313 }
1314
1315 bool BBPassManager::doInitialization(Function &F) {
1316   bool Changed = false;
1317
1318   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1319     BasicBlockPass *BP = getContainedPass(Index);
1320     Changed |= BP->doInitialization(F);
1321   }
1322
1323   return Changed;
1324 }
1325
1326 bool BBPassManager::doFinalization(Function &F) {
1327   bool Changed = false;
1328
1329   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1330     BasicBlockPass *BP = getContainedPass(Index);
1331     Changed |= BP->doFinalization(F);
1332   }
1333
1334   return Changed;
1335 }
1336
1337
1338 //===----------------------------------------------------------------------===//
1339 // FunctionPassManager implementation
1340
1341 /// Create new Function pass manager
1342 FunctionPassManager::FunctionPassManager(Module *m) : M(m) {
1343   FPM = new FunctionPassManagerImpl(0);
1344   // FPM is the top level manager.
1345   FPM->setTopLevelManager(FPM);
1346
1347   AnalysisResolver *AR = new AnalysisResolver(*FPM);
1348   FPM->setResolver(AR);
1349 }
1350
1351 FunctionPassManager::~FunctionPassManager() {
1352   delete FPM;
1353 }
1354
1355 /// addImpl - Add a pass to the queue of passes to run, without
1356 /// checking whether to add a printer pass.
1357 void FunctionPassManager::addImpl(Pass *P) {
1358   FPM->add(P);
1359 }
1360
1361 /// add - Add a pass to the queue of passes to run.  This passes
1362 /// ownership of the Pass to the PassManager.  When the
1363 /// PassManager_X is destroyed, the pass will be destroyed as well, so
1364 /// there is no need to delete the pass. (TODO delete passes.)
1365 /// This implies that all passes MUST be allocated with 'new'.
1366 void FunctionPassManager::add(Pass *P) {
1367   // If this is a not a function pass, don't add a printer for it.
1368   const void *PassID = P->getPassID();
1369   if (P->getPassKind() == PT_Function)
1370     if (ShouldPrintBeforePass(PassID))
1371       addImpl(P->createPrinterPass(dbgs(), std::string("*** IR Dump Before ")
1372                                    + P->getPassName() + " ***"));
1373
1374   addImpl(P);
1375
1376   if (P->getPassKind() == PT_Function)
1377     if (ShouldPrintAfterPass(PassID))
1378       addImpl(P->createPrinterPass(dbgs(), std::string("*** IR Dump After ")
1379                                    + P->getPassName() + " ***"));
1380 }
1381
1382 /// run - Execute all of the passes scheduled for execution.  Keep
1383 /// track of whether any of the passes modifies the function, and if
1384 /// so, return true.
1385 ///
1386 bool FunctionPassManager::run(Function &F) {
1387   if (F.isMaterializable()) {
1388     std::string errstr;
1389     if (F.Materialize(&errstr))
1390       report_fatal_error("Error reading bitcode file: " + Twine(errstr));
1391   }
1392   return FPM->run(F);
1393 }
1394
1395
1396 /// doInitialization - Run all of the initializers for the function passes.
1397 ///
1398 bool FunctionPassManager::doInitialization() {
1399   return FPM->doInitialization(*M);
1400 }
1401
1402 /// doFinalization - Run all of the finalizers for the function passes.
1403 ///
1404 bool FunctionPassManager::doFinalization() {
1405   return FPM->doFinalization(*M);
1406 }
1407
1408 //===----------------------------------------------------------------------===//
1409 // FunctionPassManagerImpl implementation
1410 //
1411 bool FunctionPassManagerImpl::doInitialization(Module &M) {
1412   bool Changed = false;
1413
1414   dumpArguments();
1415   dumpPasses();
1416
1417   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
1418     Changed |= getContainedManager(Index)->doInitialization(M);
1419
1420   return Changed;
1421 }
1422
1423 bool FunctionPassManagerImpl::doFinalization(Module &M) {
1424   bool Changed = false;
1425
1426   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
1427     Changed |= getContainedManager(Index)->doFinalization(M);
1428
1429   return Changed;
1430 }
1431
1432 /// cleanup - After running all passes, clean up pass manager cache.
1433 void FPPassManager::cleanup() {
1434  for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1435     FunctionPass *FP = getContainedPass(Index);
1436     AnalysisResolver *AR = FP->getResolver();
1437     assert(AR && "Analysis Resolver is not set");
1438     AR->clearAnalysisImpls();
1439  }
1440 }
1441
1442 void FunctionPassManagerImpl::releaseMemoryOnTheFly() {
1443   if (!wasRun)
1444     return;
1445   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index) {
1446     FPPassManager *FPPM = getContainedManager(Index);
1447     for (unsigned Index = 0; Index < FPPM->getNumContainedPasses(); ++Index) {
1448       FPPM->getContainedPass(Index)->releaseMemory();
1449     }
1450   }
1451   wasRun = false;
1452 }
1453
1454 // Execute all the passes managed by this top level manager.
1455 // Return true if any function is modified by a pass.
1456 bool FunctionPassManagerImpl::run(Function &F) {
1457   bool Changed = false;
1458   TimingInfo::createTheTimeInfo();
1459   createDebugInfoProbe();
1460
1461   initializeAllAnalysisInfo();
1462   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
1463     Changed |= getContainedManager(Index)->runOnFunction(F);
1464
1465   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
1466     getContainedManager(Index)->cleanup();
1467
1468   wasRun = true;
1469   return Changed;
1470 }
1471
1472 //===----------------------------------------------------------------------===//
1473 // FPPassManager implementation
1474
1475 char FPPassManager::ID = 0;
1476 /// Print passes managed by this manager
1477 void FPPassManager::dumpPassStructure(unsigned Offset) {
1478   llvm::dbgs() << std::string(Offset*2, ' ') << "FunctionPass Manager\n";
1479   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1480     FunctionPass *FP = getContainedPass(Index);
1481     FP->dumpPassStructure(Offset + 1);
1482     dumpLastUses(FP, Offset+1);
1483   }
1484 }
1485
1486
1487 /// Execute all of the passes scheduled for execution by invoking
1488 /// runOnFunction method.  Keep track of whether any of the passes modifies
1489 /// the function, and if so, return true.
1490 bool FPPassManager::runOnFunction(Function &F) {
1491   if (F.isDeclaration())
1492     return false;
1493
1494   bool Changed = false;
1495
1496   // Collect inherited analysis from Module level pass manager.
1497   populateInheritedAnalysis(TPM->activeStack);
1498
1499   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1500     FunctionPass *FP = getContainedPass(Index);
1501     bool LocalChanged = false;
1502
1503     dumpPassInfo(FP, EXECUTION_MSG, ON_FUNCTION_MSG, F.getName());
1504     dumpRequiredSet(FP);
1505
1506     initializeAnalysisImpl(FP);
1507     if (TheDebugProbe)
1508       TheDebugProbe->initialize(FP, F);
1509     {
1510       PassManagerPrettyStackEntry X(FP, F);
1511       TimeRegion PassTimer(getPassTimer(FP));
1512
1513       LocalChanged |= FP->runOnFunction(F);
1514     }
1515     if (TheDebugProbe)
1516       TheDebugProbe->finalize(FP, F);
1517
1518     Changed |= LocalChanged;
1519     if (LocalChanged)
1520       dumpPassInfo(FP, MODIFICATION_MSG, ON_FUNCTION_MSG, F.getName());
1521     dumpPreservedSet(FP);
1522
1523     verifyPreservedAnalysis(FP);
1524     removeNotPreservedAnalysis(FP);
1525     recordAvailableAnalysis(FP);
1526     removeDeadPasses(FP, F.getName(), ON_FUNCTION_MSG);
1527   }
1528   return Changed;
1529 }
1530
1531 bool FPPassManager::runOnModule(Module &M) {
1532   bool Changed = doInitialization(M);
1533
1534   for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
1535     runOnFunction(*I);
1536
1537   return doFinalization(M) || Changed;
1538 }
1539
1540 bool FPPassManager::doInitialization(Module &M) {
1541   bool Changed = false;
1542
1543   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index)
1544     Changed |= getContainedPass(Index)->doInitialization(M);
1545
1546   return Changed;
1547 }
1548
1549 bool FPPassManager::doFinalization(Module &M) {
1550   bool Changed = false;
1551
1552   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index)
1553     Changed |= getContainedPass(Index)->doFinalization(M);
1554
1555   return Changed;
1556 }
1557
1558 //===----------------------------------------------------------------------===//
1559 // MPPassManager implementation
1560
1561 /// Execute all of the passes scheduled for execution by invoking
1562 /// runOnModule method.  Keep track of whether any of the passes modifies
1563 /// the module, and if so, return true.
1564 bool
1565 MPPassManager::runOnModule(Module &M) {
1566   bool Changed = false;
1567
1568   // Initialize 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     Changed |= FPP->doInitialization(M);
1574   }
1575
1576   for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1577     ModulePass *MP = getContainedPass(Index);
1578     bool LocalChanged = false;
1579
1580     dumpPassInfo(MP, EXECUTION_MSG, ON_MODULE_MSG, M.getModuleIdentifier());
1581     dumpRequiredSet(MP);
1582
1583     initializeAnalysisImpl(MP);
1584
1585     {
1586       PassManagerPrettyStackEntry X(MP, M);
1587       TimeRegion PassTimer(getPassTimer(MP));
1588
1589       LocalChanged |= MP->runOnModule(M);
1590     }
1591
1592     Changed |= LocalChanged;
1593     if (LocalChanged)
1594       dumpPassInfo(MP, MODIFICATION_MSG, ON_MODULE_MSG,
1595                    M.getModuleIdentifier());
1596     dumpPreservedSet(MP);
1597
1598     verifyPreservedAnalysis(MP);
1599     removeNotPreservedAnalysis(MP);
1600     recordAvailableAnalysis(MP);
1601     removeDeadPasses(MP, M.getModuleIdentifier(), ON_MODULE_MSG);
1602   }
1603
1604   // Finalize on-the-fly passes
1605   for (std::map<Pass *, FunctionPassManagerImpl *>::iterator
1606        I = OnTheFlyManagers.begin(), E = OnTheFlyManagers.end();
1607        I != E; ++I) {
1608     FunctionPassManagerImpl *FPP = I->second;
1609     // We don't know when is the last time an on-the-fly pass is run,
1610     // so we need to releaseMemory / finalize here
1611     FPP->releaseMemoryOnTheFly();
1612     Changed |= FPP->doFinalization(M);
1613   }
1614   return Changed;
1615 }
1616
1617 /// Add RequiredPass into list of lower level passes required by pass P.
1618 /// RequiredPass is run on the fly by Pass Manager when P requests it
1619 /// through getAnalysis interface.
1620 void MPPassManager::addLowerLevelRequiredPass(Pass *P, Pass *RequiredPass) {
1621   assert(P->getPotentialPassManagerType() == PMT_ModulePassManager &&
1622          "Unable to handle Pass that requires lower level Analysis pass");
1623   assert((P->getPotentialPassManagerType() <
1624           RequiredPass->getPotentialPassManagerType()) &&
1625          "Unable to handle Pass that requires lower level Analysis pass");
1626
1627   FunctionPassManagerImpl *FPP = OnTheFlyManagers[P];
1628   if (!FPP) {
1629     FPP = new FunctionPassManagerImpl(0);
1630     // FPP is the top level manager.
1631     FPP->setTopLevelManager(FPP);
1632
1633     OnTheFlyManagers[P] = FPP;
1634   }
1635   FPP->add(RequiredPass);
1636
1637   // Register P as the last user of RequiredPass.
1638   SmallVector<Pass *, 1> LU;
1639   LU.push_back(RequiredPass);
1640   FPP->setLastUser(LU,  P);
1641 }
1642
1643 /// Return function pass corresponding to PassInfo PI, that is
1644 /// required by module pass MP. Instantiate analysis pass, by using
1645 /// its runOnFunction() for function F.
1646 Pass* MPPassManager::getOnTheFlyPass(Pass *MP, AnalysisID PI, Function &F){
1647   FunctionPassManagerImpl *FPP = OnTheFlyManagers[MP];
1648   assert(FPP && "Unable to find on the fly pass");
1649
1650   FPP->releaseMemoryOnTheFly();
1651   FPP->run(F);
1652   return ((PMTopLevelManager*)FPP)->findAnalysisPass(PI);
1653 }
1654
1655
1656 //===----------------------------------------------------------------------===//
1657 // PassManagerImpl implementation
1658 //
1659 /// run - Execute all of the passes scheduled for execution.  Keep track of
1660 /// whether any of the passes modifies the module, and if so, return true.
1661 bool PassManagerImpl::run(Module &M) {
1662   bool Changed = false;
1663   TimingInfo::createTheTimeInfo();
1664   createDebugInfoProbe();
1665
1666   dumpArguments();
1667   dumpPasses();
1668
1669   initializeAllAnalysisInfo();
1670   for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
1671     Changed |= getContainedManager(Index)->runOnModule(M);
1672   return Changed;
1673 }
1674
1675 //===----------------------------------------------------------------------===//
1676 // PassManager implementation
1677
1678 /// Create new pass manager
1679 PassManager::PassManager() {
1680   PM = new PassManagerImpl(0);
1681   // PM is the top level manager
1682   PM->setTopLevelManager(PM);
1683 }
1684
1685 PassManager::~PassManager() {
1686   delete PM;
1687 }
1688
1689 /// addImpl - Add a pass to the queue of passes to run, without
1690 /// checking whether to add a printer pass.
1691 void PassManager::addImpl(Pass *P) {
1692   PM->add(P);
1693 }
1694
1695 /// add - Add a pass to the queue of passes to run.  This passes ownership of
1696 /// the Pass to the PassManager.  When the PassManager is destroyed, the pass
1697 /// will be destroyed as well, so there is no need to delete the pass.  This
1698 /// implies that all passes MUST be allocated with 'new'.
1699 void PassManager::add(Pass *P) {
1700   const void* PassID = P->getPassID();
1701   if (ShouldPrintBeforePass(PassID))
1702     addImpl(P->createPrinterPass(dbgs(), std::string("*** IR Dump Before ")
1703                                  + P->getPassName() + " ***"));
1704
1705   addImpl(P);
1706
1707   if (ShouldPrintAfterPass(PassID))
1708     addImpl(P->createPrinterPass(dbgs(), std::string("*** IR Dump After ")
1709                                  + P->getPassName() + " ***"));
1710 }
1711
1712 /// run - Execute all of the passes scheduled for execution.  Keep track of
1713 /// whether any of the passes modifies the module, and if so, return true.
1714 bool PassManager::run(Module &M) {
1715   return PM->run(M);
1716 }
1717
1718 //===----------------------------------------------------------------------===//
1719 // TimingInfo Class - This class is used to calculate information about the
1720 // amount of time each pass takes to execute.  This only happens with
1721 // -time-passes is enabled on the command line.
1722 //
1723 bool llvm::TimePassesIsEnabled = false;
1724 static cl::opt<bool,true>
1725 EnableTiming("time-passes", cl::location(TimePassesIsEnabled),
1726             cl::desc("Time each pass, printing elapsed time for each on exit"));
1727
1728 // createTheTimeInfo - This method either initializes the TheTimeInfo pointer to
1729 // a non null value (if the -time-passes option is enabled) or it leaves it
1730 // null.  It may be called multiple times.
1731 void TimingInfo::createTheTimeInfo() {
1732   if (!TimePassesIsEnabled || TheTimeInfo) return;
1733
1734   // Constructed the first time this is called, iff -time-passes is enabled.
1735   // This guarantees that the object will be constructed before static globals,
1736   // thus it will be destroyed before them.
1737   static ManagedStatic<TimingInfo> TTI;
1738   TheTimeInfo = &*TTI;
1739 }
1740
1741 /// If TimingInfo is enabled then start pass timer.
1742 Timer *llvm::getPassTimer(Pass *P) {
1743   if (TheTimeInfo)
1744     return TheTimeInfo->getPassTimer(P);
1745   return 0;
1746 }
1747
1748 //===----------------------------------------------------------------------===//
1749 // PMStack implementation
1750 //
1751
1752 // Pop Pass Manager from the stack and clear its analysis info.
1753 void PMStack::pop() {
1754
1755   PMDataManager *Top = this->top();
1756   Top->initializeAnalysisInfo();
1757
1758   S.pop_back();
1759 }
1760
1761 // Push PM on the stack and set its top level manager.
1762 void PMStack::push(PMDataManager *PM) {
1763   assert(PM && "Unable to push. Pass Manager expected");
1764
1765   if (!this->empty()) {
1766     PMTopLevelManager *TPM = this->top()->getTopLevelManager();
1767
1768     assert(TPM && "Unable to find top level manager");
1769     TPM->addIndirectPassManager(PM);
1770     PM->setTopLevelManager(TPM);
1771   }
1772
1773   S.push_back(PM);
1774 }
1775
1776 // Dump content of the pass manager stack.
1777 void PMStack::dump() const {
1778   for (std::vector<PMDataManager *>::const_iterator I = S.begin(),
1779          E = S.end(); I != E; ++I)
1780     printf("%s ", (*I)->getAsPass()->getPassName());
1781
1782   if (!S.empty())
1783     printf("\n");
1784 }
1785
1786 /// Find appropriate Module Pass Manager in the PM Stack and
1787 /// add self into that manager.
1788 void ModulePass::assignPassManager(PMStack &PMS,
1789                                    PassManagerType PreferredType) {
1790   // Find Module Pass Manager
1791   while (!PMS.empty()) {
1792     PassManagerType TopPMType = PMS.top()->getPassManagerType();
1793     if (TopPMType == PreferredType)
1794       break; // We found desired pass manager
1795     else if (TopPMType > PMT_ModulePassManager)
1796       PMS.pop();    // Pop children pass managers
1797     else
1798       break;
1799   }
1800   assert(!PMS.empty() && "Unable to find appropriate Pass Manager");
1801   PMS.top()->add(this);
1802 }
1803
1804 /// Find appropriate Function Pass Manager or Call Graph Pass Manager
1805 /// in the PM Stack and add self into that manager.
1806 void FunctionPass::assignPassManager(PMStack &PMS,
1807                                      PassManagerType PreferredType) {
1808
1809   // Find Module Pass Manager
1810   while (!PMS.empty()) {
1811     if (PMS.top()->getPassManagerType() > PMT_FunctionPassManager)
1812       PMS.pop();
1813     else
1814       break;
1815   }
1816
1817   // Create new Function Pass Manager if needed.
1818   FPPassManager *FPP;
1819   if (PMS.top()->getPassManagerType() == PMT_FunctionPassManager) {
1820     FPP = (FPPassManager *)PMS.top();
1821   } else {
1822     assert(!PMS.empty() && "Unable to create Function Pass Manager");
1823     PMDataManager *PMD = PMS.top();
1824
1825     // [1] Create new Function Pass Manager
1826     FPP = new FPPassManager(PMD->getDepth() + 1);
1827     FPP->populateInheritedAnalysis(PMS);
1828
1829     // [2] Set up new manager's top level manager
1830     PMTopLevelManager *TPM = PMD->getTopLevelManager();
1831     TPM->addIndirectPassManager(FPP);
1832
1833     // [3] Assign manager to manage this new manager. This may create
1834     // and push new managers into PMS
1835     FPP->assignPassManager(PMS, PMD->getPassManagerType());
1836
1837     // [4] Push new manager into PMS
1838     PMS.push(FPP);
1839   }
1840
1841   // Assign FPP as the manager of this pass.
1842   FPP->add(this);
1843 }
1844
1845 /// Find appropriate Basic Pass Manager or Call Graph Pass Manager
1846 /// in the PM Stack and add self into that manager.
1847 void BasicBlockPass::assignPassManager(PMStack &PMS,
1848                                        PassManagerType PreferredType) {
1849   BBPassManager *BBP;
1850
1851   // Basic Pass Manager is a leaf pass manager. It does not handle
1852   // any other pass manager.
1853   if (!PMS.empty() &&
1854       PMS.top()->getPassManagerType() == PMT_BasicBlockPassManager) {
1855     BBP = (BBPassManager *)PMS.top();
1856   } else {
1857     // If leaf manager is not Basic Block Pass manager then create new
1858     // basic Block Pass manager.
1859     assert(!PMS.empty() && "Unable to create BasicBlock Pass Manager");
1860     PMDataManager *PMD = PMS.top();
1861
1862     // [1] Create new Basic Block Manager
1863     BBP = new BBPassManager(PMD->getDepth() + 1);
1864
1865     // [2] Set up new manager's top level manager
1866     // Basic Block Pass Manager does not live by itself
1867     PMTopLevelManager *TPM = PMD->getTopLevelManager();
1868     TPM->addIndirectPassManager(BBP);
1869
1870     // [3] Assign manager to manage this new manager. This may create
1871     // and push new managers into PMS
1872     BBP->assignPassManager(PMS, PreferredType);
1873
1874     // [4] Push new manager into PMS
1875     PMS.push(BBP);
1876   }
1877
1878   // Assign BBP as the manager of this pass.
1879   BBP->add(this);
1880 }
1881
1882 PassManagerBase::~PassManagerBase() {}