lib/VMCore/Pass.cpp

   1 //===- Pass.cpp - LLVM Pass Infrastructure Implementation -----------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file was developed by the LLVM research group and is distributed under
   6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file implements the LLVM Pass infrastructure.  It is primarily
  11 // responsible with ensuring that passes are executed and batched together
  12 // optimally.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #include "llvm/PassManager.h"
  17 #include "PassManagerT.h"         // PassManagerT implementation
  18 #include "llvm/Module.h"
  19 #include "llvm/ModuleProvider.h"
  20 #include "llvm/ADT/STLExtras.h"
  21 #include "llvm/Support/TypeInfo.h"
  22 #include <iostream>
  23 #include <set>
  24 using namespace llvm;
  25
  26 //===----------------------------------------------------------------------===//
  27 //   AnalysisID Class Implementation
  28 //
  29
  30 // getCFGOnlyAnalyses - A wrapper around the CFGOnlyAnalyses which make it
  31 // initializer order independent.
  32 static std::vector<const PassInfo*> &getCFGOnlyAnalyses() {
  33   static std::vector<const PassInfo*> CFGOnlyAnalyses;
  34   return CFGOnlyAnalyses;
  35 }
  36
  37 void RegisterPassBase::setOnlyUsesCFG() {
  38   getCFGOnlyAnalyses().push_back(&PIObj);
  39 }
  40
  41 //===----------------------------------------------------------------------===//
  42 //   AnalysisResolver Class Implementation
  43 //
  44
  45 AnalysisResolver::~AnalysisResolver() {
  46 }
  47 void AnalysisResolver::setAnalysisResolver(Pass *P, AnalysisResolver *AR) {
  48   assert(P->Resolver == 0 && "Pass already in a PassManager!");
  49   P->Resolver = AR;
  50 }
  51
  52 //===----------------------------------------------------------------------===//
  53 //   AnalysisUsage Class Implementation
  54 //
  55
  56 // setPreservesCFG - This function should be called to by the pass, iff they do
  57 // not:
  58 //
  59 //  1. Add or remove basic blocks from the function
  60 //  2. Modify terminator instructions in any way.
  61 //
  62 // This function annotates the AnalysisUsage info object to say that analyses
  63 // that only depend on the CFG are preserved by this pass.
  64 //
  65 void AnalysisUsage::setPreservesCFG() {
  66   // Since this transformation doesn't modify the CFG, it preserves all analyses
  67   // that only depend on the CFG (like dominators, loop info, etc...)
  68   //
  69   Preserved.insert(Preserved.end(),
  70                    getCFGOnlyAnalyses().begin(), getCFGOnlyAnalyses().end());
  71 }
  72
  73
  74 //===----------------------------------------------------------------------===//
  75 // PassManager implementation - The PassManager class is a simple Pimpl class
  76 // that wraps the PassManagerT template.
  77 //
  78 PassManager::PassManager() : PM(new ModulePassManager()) {}
  79 PassManager::~PassManager() { delete PM; }
  80 void PassManager::add(Pass *P) {
  81   ModulePass *MP = dynamic_cast<ModulePass*>(P);
  82   assert(MP && "Not a modulepass?");
  83   PM->add(MP);
  84 }
  85 bool PassManager::run(Module &M) { return PM->runOnModule(M); }
  86
  87 //===----------------------------------------------------------------------===//
  88 // FunctionPassManager implementation - The FunctionPassManager class
  89 // is a simple Pimpl class that wraps the PassManagerT template. It
  90 // is like PassManager, but only deals in FunctionPasses.
  91 //
  92 FunctionPassManager::FunctionPassManager(ModuleProvider *P) :
  93   PM(new FunctionPassManagerT()), MP(P) {}
  94 FunctionPassManager::~FunctionPassManager() { delete PM; }
  95 void FunctionPassManager::add(FunctionPass *P) { PM->add(P); }
  96 void FunctionPassManager::add(ImmutablePass *IP) { PM->add(IP); }
  97 bool FunctionPassManager::run(Function &F) {
  98   std::string errstr;
  99   if (MP->materializeFunction(&F, &errstr)) {
 100     std::cerr << "Error reading bytecode file: " << errstr << "\n";
 101     abort();
 102   }
 103   return PM->run(F);
 104 }
 105
 106
 107 //===----------------------------------------------------------------------===//
 108 // TimingInfo Class - This class is used to calculate information about the
 109 // amount of time each pass takes to execute.  This only happens with
 110 // -time-passes is enabled on the command line.
 111 //
 112 bool llvm::TimePassesIsEnabled = false;
 113 static cl::opt<bool,true>
 114 EnableTiming("time-passes", cl::location(TimePassesIsEnabled),
 115             cl::desc("Time each pass, printing elapsed time for each on exit"));
 116
 117 // createTheTimeInfo - This method either initializes the TheTimeInfo pointer to
 118 // a non null value (if the -time-passes option is enabled) or it leaves it
 119 // null.  It may be called multiple times.
 120 void TimingInfo::createTheTimeInfo() {
 121   if (!TimePassesIsEnabled || TheTimeInfo) return;
 122
 123   // Constructed the first time this is called, iff -time-passes is enabled.
 124   // This guarantees that the object will be constructed before static globals,
 125   // thus it will be destroyed before them.
 126   static TimingInfo TTI;
 127   TheTimeInfo = &TTI;
 128 }
 129
 130 void PMDebug::PrintArgumentInformation(const Pass *P) {
 131   // Print out passes in pass manager...
 132   if (const AnalysisResolver *PM = dynamic_cast<const AnalysisResolver*>(P)) {
 133     for (unsigned i = 0, e = PM->getNumContainedPasses(); i != e; ++i)
 134       PrintArgumentInformation(PM->getContainedPass(i));
 135
 136   } else {  // Normal pass.  Print argument information...
 137     // Print out arguments for registered passes that are _optimizations_
 138     if (const PassInfo *PI = P->getPassInfo())
 139       if (PI->getPassType() & PassInfo::Optimization)
 140         std::cerr << " -" << PI->getPassArgument();
 141   }
 142 }
 143
 144 void PMDebug::PrintPassInformation(unsigned Depth, const char *Action,
 145                                    Pass *P, Module *M) {
 146   if (PassDebugging >= Executions) {
 147     std::cerr << (void*)P << std::string(Depth*2+1, ' ') << Action << " '"
 148               << P->getPassName();
 149     if (M) std::cerr << "' on Module '" << M->getModuleIdentifier() << "'\n";
 150     std::cerr << "'...\n";
 151   }
 152 }
 153
 154 void PMDebug::PrintPassInformation(unsigned Depth, const char *Action,
 155                                    Pass *P, Function *F) {
 156   if (PassDebugging >= Executions) {
 157     std::cerr << (void*)P << std::string(Depth*2+1, ' ') << Action << " '"
 158               << P->getPassName();
 159     if (F) std::cerr << "' on Function '" << F->getName();
 160     std::cerr << "'...\n";
 161   }
 162 }
 163
 164 void PMDebug::PrintPassInformation(unsigned Depth, const char *Action,
 165                                    Pass *P, BasicBlock *BB) {
 166   if (PassDebugging >= Executions) {
 167     std::cerr << (void*)P << std::string(Depth*2+1, ' ') << Action << " '"
 168               << P->getPassName();
 169     if (BB) std::cerr << "' on BasicBlock '" << BB->getName();
 170     std::cerr << "'...\n";
 171   }
 172 }
 173
 174 void PMDebug::PrintAnalysisSetInfo(unsigned Depth, const char *Msg,
 175                                    Pass *P, const std::vector<AnalysisID> &Set){
 176   if (PassDebugging >= Details && !Set.empty()) {
 177     std::cerr << (void*)P << std::string(Depth*2+3, ' ') << Msg << " Analyses:";
 178     for (unsigned i = 0; i != Set.size(); ++i) {
 179       if (i) std::cerr << ",";
 180       std::cerr << " " << Set[i]->getPassName();
 181     }
 182     std::cerr << "\n";
 183   }
 184 }
 185
 186 //===----------------------------------------------------------------------===//
 187 // Pass Implementation
 188 //
 189
 190 void ModulePass::addToPassManager(ModulePassManager *PM, AnalysisUsage &AU) {
 191   PM->addPass(this, AU);
 192 }
 193
 194 bool Pass::mustPreserveAnalysisID(const PassInfo *AnalysisID) const {
 195   return Resolver->getAnalysisToUpdate(AnalysisID) != 0;
 196 }
 197
 198 // dumpPassStructure - Implement the -debug-passes=Structure option
 199 void Pass::dumpPassStructure(unsigned Offset) {
 200   std::cerr << std::string(Offset*2, ' ') << getPassName() << "\n";
 201 }
 202
 203 // getPassName - Use C++ RTTI to get a SOMEWHAT intelligible name for the pass.
 204 //
 205 const char *Pass::getPassName() const {
 206   if (const PassInfo *PI = getPassInfo())
 207     return PI->getPassName();
 208   return typeid(*this).name();
 209 }
 210
 211 // print - Print out the internal state of the pass.  This is called by Analyze
 212 // to print out the contents of an analysis.  Otherwise it is not necessary to
 213 // implement this method.
 214 //
 215 void Pass::print(std::ostream &O,const Module*) const {
 216   O << "Pass::print not implemented for pass: '" << getPassName() << "'!\n";
 217 }
 218
 219 // dump - call print(std::cerr);
 220 void Pass::dump() const {
 221   print(std::cerr, 0);
 222 }
 223
 224 //===----------------------------------------------------------------------===//
 225 // ImmutablePass Implementation
 226 //
 227 void ImmutablePass::addToPassManager(ModulePassManager *PM,
 228                                      AnalysisUsage &AU) {
 229   PM->addPass(this, AU);
 230 }
 231
 232
 233 //===----------------------------------------------------------------------===//
 234 // FunctionPass Implementation
 235 //
 236
 237 // run - On a module, we run this pass by initializing, runOnFunction'ing once
 238 // for every function in the module, then by finalizing.
 239 //
 240 bool FunctionPass::runOnModule(Module &M) {
 241   bool Changed = doInitialization(M);
 242
 243   for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
 244     if (!I->isExternal())      // Passes are not run on external functions!
 245     Changed |= runOnFunction(*I);
 246
 247   return Changed | doFinalization(M);
 248 }
 249
 250 // run - On a function, we simply initialize, run the function, then finalize.
 251 //
 252 bool FunctionPass::run(Function &F) {
 253   if (F.isExternal()) return false;// Passes are not run on external functions!
 254
 255   bool Changed = doInitialization(*F.getParent());
 256   Changed |= runOnFunction(F);
 257   return Changed | doFinalization(*F.getParent());
 258 }
 259
 260 void FunctionPass::addToPassManager(ModulePassManager *PM,
 261                                     AnalysisUsage &AU) {
 262   PM->addPass(this, AU);
 263 }
 264
 265 void FunctionPass::addToPassManager(FunctionPassManagerT *PM,
 266                                     AnalysisUsage &AU) {
 267   PM->addPass(this, AU);
 268 }
 269
 270 //===----------------------------------------------------------------------===//
 271 // BasicBlockPass Implementation
 272 //
 273
 274 // To run this pass on a function, we simply call runOnBasicBlock once for each
 275 // function.
 276 //
 277 bool BasicBlockPass::runOnFunction(Function &F) {
 278   bool Changed = doInitialization(F);
 279   for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
 280     Changed |= runOnBasicBlock(*I);
 281   return Changed | doFinalization(F);
 282 }
 283
 284 // To run directly on the basic block, we initialize, runOnBasicBlock, then
 285 // finalize.
 286 //
 287 bool BasicBlockPass::runPass(BasicBlock &BB) {
 288   Function &F = *BB.getParent();
 289   Module &M = *F.getParent();
 290   bool Changed = doInitialization(M);
 291   Changed |= doInitialization(F);
 292   Changed |= runOnBasicBlock(BB);
 293   Changed |= doFinalization(F);
 294   Changed |= doFinalization(M);
 295   return Changed;
 296 }
 297
 298 void BasicBlockPass::addToPassManager(FunctionPassManagerT *PM,
 299                                       AnalysisUsage &AU) {
 300   PM->addPass(this, AU);
 301 }
 302
 303 void BasicBlockPass::addToPassManager(BasicBlockPassManager *PM,
 304                                       AnalysisUsage &AU) {
 305   PM->addPass(this, AU);
 306 }
 307
 308
 309 //===----------------------------------------------------------------------===//
 310 // Pass Registration mechanism
 311 //
 312 static std::map<TypeInfo, PassInfo*> *PassInfoMap = 0;
 313 static std::vector<PassRegistrationListener*> *Listeners = 0;
 314
 315 // getPassInfo - Return the PassInfo data structure that corresponds to this
 316 // pass...
 317 const PassInfo *Pass::getPassInfo() const {
 318   if (PassInfoCache) return PassInfoCache;
 319   return lookupPassInfo(typeid(*this));
 320 }
 321
 322 const PassInfo *Pass::lookupPassInfo(const std::type_info &TI) {
 323   if (PassInfoMap == 0) return 0;
 324   std::map<TypeInfo, PassInfo*>::iterator I = PassInfoMap->find(TI);
 325   return (I != PassInfoMap->end()) ? I->second : 0;
 326 }
 327
 328 void RegisterPassBase::registerPass() {
 329   if (PassInfoMap == 0)
 330     PassInfoMap = new std::map<TypeInfo, PassInfo*>();
 331
 332   assert(PassInfoMap->find(PIObj.getTypeInfo()) == PassInfoMap->end() &&
 333          "Pass already registered!");
 334   PassInfoMap->insert(std::make_pair(TypeInfo(PIObj.getTypeInfo()), &PIObj));
 335
 336   // Notify any listeners...
 337   if (Listeners)
 338     for (std::vector<PassRegistrationListener*>::iterator
 339            I = Listeners->begin(), E = Listeners->end(); I != E; ++I)
 340       (*I)->passRegistered(&PIObj);
 341 }
 342
 343 void RegisterPassBase::unregisterPass() {
 344   assert(PassInfoMap && "Pass registered but not in map!");
 345   std::map<TypeInfo, PassInfo*>::iterator I =
 346     PassInfoMap->find(PIObj.getTypeInfo());
 347   assert(I != PassInfoMap->end() && "Pass registered but not in map!");
 348
 349   // Remove pass from the map...
 350   PassInfoMap->erase(I);
 351   if (PassInfoMap->empty()) {
 352     delete PassInfoMap;
 353     PassInfoMap = 0;
 354   }
 355
 356   // Notify any listeners...
 357   if (Listeners)
 358     for (std::vector<PassRegistrationListener*>::iterator
 359            I = Listeners->begin(), E = Listeners->end(); I != E; ++I)
 360       (*I)->passUnregistered(&PIObj);
 361 }
 362
 363 //===----------------------------------------------------------------------===//
 364 //                  Analysis Group Implementation Code
 365 //===----------------------------------------------------------------------===//
 366
 367 struct AnalysisGroupInfo {
 368   const PassInfo *DefaultImpl;
 369   std::set<const PassInfo *> Implementations;
 370   AnalysisGroupInfo() : DefaultImpl(0) {}
 371 };
 372
 373 static std::map<const PassInfo *, AnalysisGroupInfo> *AnalysisGroupInfoMap = 0;
 374
 375 // RegisterAGBase implementation
 376 //
 377 RegisterAGBase::RegisterAGBase(const std::type_info &Interface,
 378                                const std::type_info *Pass, bool isDefault)
 379   : RegisterPassBase(Interface, PassInfo::AnalysisGroup),
 380     ImplementationInfo(0), isDefaultImplementation(isDefault) {
 381
 382   InterfaceInfo = const_cast<PassInfo*>(Pass::lookupPassInfo(Interface));
 383   if (InterfaceInfo == 0) {
 384     // First reference to Interface, register it now.
 385     registerPass();
 386     InterfaceInfo = &PIObj;
 387   }
 388   assert(InterfaceInfo->getPassType() == PassInfo::AnalysisGroup &&
 389          "Trying to join an analysis group that is a normal pass!");
 390
 391   if (Pass) {
 392     ImplementationInfo = Pass::lookupPassInfo(*Pass);
 393     assert(ImplementationInfo &&
 394            "Must register pass before adding to AnalysisGroup!");
 395
 396     // Make sure we keep track of the fact that the implementation implements
 397     // the interface.
 398     PassInfo *IIPI = const_cast<PassInfo*>(ImplementationInfo);
 399     IIPI->addInterfaceImplemented(InterfaceInfo);
 400
 401     // Lazily allocate to avoid nasty initialization order dependencies
 402     if (AnalysisGroupInfoMap == 0)
 403       AnalysisGroupInfoMap = new std::map<const PassInfo *,AnalysisGroupInfo>();
 404
 405     AnalysisGroupInfo &AGI = (*AnalysisGroupInfoMap)[InterfaceInfo];
 406     assert(AGI.Implementations.count(ImplementationInfo) == 0 &&
 407            "Cannot add a pass to the same analysis group more than once!");
 408     AGI.Implementations.insert(ImplementationInfo);
 409     if (isDefault) {
 410       assert(AGI.DefaultImpl == 0 && InterfaceInfo->getNormalCtor() == 0 &&
 411              "Default implementation for analysis group already specified!");
 412       assert(ImplementationInfo->getNormalCtor() &&
 413            "Cannot specify pass as default if it does not have a default ctor");
 414       AGI.DefaultImpl = ImplementationInfo;
 415       InterfaceInfo->setNormalCtor(ImplementationInfo->getNormalCtor());
 416     }
 417   }
 418 }
 419
 420 void RegisterAGBase::setGroupName(const char *Name) {
 421   assert(InterfaceInfo->getPassName()[0] == 0 && "Interface Name already set!");
 422   InterfaceInfo->setPassName(Name);
 423 }
 424
 425 RegisterAGBase::~RegisterAGBase() {
 426   if (ImplementationInfo) {
 427     assert(AnalysisGroupInfoMap && "Inserted into map, but map doesn't exist?");
 428     AnalysisGroupInfo &AGI = (*AnalysisGroupInfoMap)[InterfaceInfo];
 429
 430     assert(AGI.Implementations.count(ImplementationInfo) &&
 431            "Pass not a member of analysis group?");
 432
 433     if (AGI.DefaultImpl == ImplementationInfo)
 434       AGI.DefaultImpl = 0;
 435
 436     AGI.Implementations.erase(ImplementationInfo);
 437
 438     // Last member of this analysis group? Unregister PassInfo, delete map entry
 439     if (AGI.Implementations.empty()) {
 440       assert(AGI.DefaultImpl == 0 &&
 441              "Default implementation didn't unregister?");
 442       AnalysisGroupInfoMap->erase(InterfaceInfo);
 443       if (AnalysisGroupInfoMap->empty()) {  // Delete map if empty
 444         delete AnalysisGroupInfoMap;
 445         AnalysisGroupInfoMap = 0;
 446       }
 447     }
 448   }
 449
 450   if (InterfaceInfo == &PIObj)
 451     unregisterPass();
 452 }
 453
 454
 455 //===----------------------------------------------------------------------===//
 456 // PassRegistrationListener implementation
 457 //
 458
 459 // PassRegistrationListener ctor - Add the current object to the list of
 460 // PassRegistrationListeners...
 461 PassRegistrationListener::PassRegistrationListener() {
 462   if (!Listeners) Listeners = new std::vector<PassRegistrationListener*>();
 463   Listeners->push_back(this);
 464 }
 465
 466 // dtor - Remove object from list of listeners...
 467 PassRegistrationListener::~PassRegistrationListener() {
 468   std::vector<PassRegistrationListener*>::iterator I =
 469     std::find(Listeners->begin(), Listeners->end(), this);
 470   assert(Listeners && I != Listeners->end() &&
 471          "PassRegistrationListener not registered!");
 472   Listeners->erase(I);
 473
 474   if (Listeners->empty()) {
 475     delete Listeners;
 476     Listeners = 0;
 477   }
 478 }
 479
 480 // enumeratePasses - Iterate over the registered passes, calling the
 481 // passEnumerate callback on each PassInfo object.
 482 //
 483 void PassRegistrationListener::enumeratePasses() {
 484   if (PassInfoMap)
 485     for (std::map<TypeInfo, PassInfo*>::iterator I = PassInfoMap->begin(),
 486            E = PassInfoMap->end(); I != E; ++I)
 487       passEnumerate(I->second);
 488 }
 489