llvm/lib/VMCore/Pass.cpp

//===- Pass.cpp - LLVM Pass Infrastructure Impementation ------------------===//
//
// This file implements the LLVM Pass infrastructure.  It is primarily
// responsible with ensuring that passes are executed and batched together
// optimally.
//
//===----------------------------------------------------------------------===//

#include "llvm/PassManager.h"
#include "PassManagerT.h"         // PassManagerT implementation
#include "llvm/Module.h"
#include "Support/STLExtras.h"
#include "Support/TypeInfo.h"
#include <stdio.h>
#include <sys/resource.h>
#include <sys/unistd.h>
#include <set>

// IncludeFile - Stub function used to help linking out.
IncludeFile::IncludeFile(void*) {}

//===----------------------------------------------------------------------===//
//   AnalysisID Class Implementation
//

static std::vector<const PassInfo*> CFGOnlyAnalyses;

void RegisterPassBase::setPreservesCFG() {
  CFGOnlyAnalyses.push_back(PIObj);
}

//===----------------------------------------------------------------------===//
//   AnalysisResolver Class Implementation
//

void AnalysisResolver::setAnalysisResolver(Pass *P, AnalysisResolver *AR) {
  assert(P->Resolver == 0 && "Pass already in a PassManager!");
  P->Resolver = AR;
}

//===----------------------------------------------------------------------===//
//   AnalysisUsage Class Implementation
//

// preservesCFG - This function should be called to by the pass, iff they do
// not:
//
//  1. Add or remove basic blocks from the function
//  2. Modify terminator instructions in any way.
//
// This function annotates the AnalysisUsage info object to say that analyses
// that only depend on the CFG are preserved by this pass.
//
void AnalysisUsage::preservesCFG() {
  // Since this transformation doesn't modify the CFG, it preserves all analyses
  // that only depend on the CFG (like dominators, loop info, etc...)
  //
  Preserved.insert(Preserved.end(),
                   CFGOnlyAnalyses.begin(), CFGOnlyAnalyses.end());
}


//===----------------------------------------------------------------------===//
// PassManager implementation - The PassManager class is a simple Pimpl class
// that wraps the PassManagerT template.
//
PassManager::PassManager() : PM(new PassManagerT<Module>()) {}
PassManager::~PassManager() { delete PM; }
void PassManager::add(Pass *P) { PM->add(P); }
bool PassManager::run(Module &M) { return PM->run(M); }


//===----------------------------------------------------------------------===//
// TimingInfo Class - This class is used to calculate information about the
// amount of time each pass takes to execute.  This only happens with
// -time-passes is enabled on the command line.
//
static cl::opt<bool>
EnableTiming("time-passes",
            cl::desc("Time each pass, printing elapsed time for each on exit"));

static TimeRecord getTimeRecord() {
  static unsigned long PageSize = 0;

  if (PageSize == 0) {
#ifdef _SC_PAGE_SIZE
    PageSize = sysconf(_SC_PAGE_SIZE);
#else
#ifdef _SC_PAGESIZE
    PageSize = sysconf(_SC_PAGESIZE);
#else
    PageSize = getpagesize();
#endif
#endif
  }

  struct rusage RU;
  struct timeval T;
  gettimeofday(&T, 0);
  if (getrusage(RUSAGE_SELF, &RU)) {
    perror("getrusage call failed: -time-passes info incorrect!");
  }

  TimeRecord Result;
  Result.Elapsed    =           T.tv_sec +           T.tv_usec/1000000.0;
  Result.UserTime   = RU.ru_utime.tv_sec + RU.ru_utime.tv_usec/1000000.0;
  Result.SystemTime = RU.ru_stime.tv_sec + RU.ru_stime.tv_usec/1000000.0;
  Result.MaxRSS = RU.ru_maxrss*PageSize;

  return Result;
}

bool TimeRecord::operator<(const TimeRecord &TR) const {
  // Primary sort key is User+System time
  if (UserTime+SystemTime < TR.UserTime+TR.SystemTime)
    return true;
  if (UserTime+SystemTime > TR.UserTime+TR.SystemTime)
    return false;

  // Secondary sort key is Wall Time
  return Elapsed < TR.Elapsed;
}

void TimeRecord::passStart(const TimeRecord &T) {
  Elapsed    -= T.Elapsed;
  UserTime   -= T.UserTime;
  SystemTime -= T.SystemTime;
  RSSTemp     = T.MaxRSS;
}

void TimeRecord::passEnd(const TimeRecord &T) {
  Elapsed    += T.Elapsed;
  UserTime   += T.UserTime;
  SystemTime += T.SystemTime;
  RSSTemp     = T.MaxRSS - RSSTemp;
  MaxRSS      = std::max(MaxRSS, RSSTemp);
}

static void printVal(double Val, double Total) {
  if (Total < 1e-7)   // Avoid dividing by zero...
    fprintf(stderr, "        -----     ");
  else
    fprintf(stderr, "  %7.4f (%5.1f%%)", Val, Val*100/Total);
}

void TimeRecord::print(const char *PassName, const TimeRecord &Total) const {
  printVal(UserTime, Total.UserTime);
  printVal(SystemTime, Total.SystemTime);
  printVal(UserTime+SystemTime, Total.UserTime+Total.SystemTime);
  printVal(Elapsed, Total.Elapsed);
  
  fprintf(stderr, "  ");

  if (Total.MaxRSS)
    std::cerr << MaxRSS << "\t";
  std::cerr << PassName << "\n";
}


// Create method.  If Timing is enabled, this creates and returns a new timing
// object, otherwise it returns null.
//
TimingInfo *TimingInfo::create() {
  return EnableTiming ? new TimingInfo() : 0;
}

void TimingInfo::passStarted(Pass *P) {
  TimingData[P].passStart(getTimeRecord());
}
void TimingInfo::passEnded(Pass *P) {
  TimingData[P].passEnd(getTimeRecord());
}
void TimeRecord::sum(const TimeRecord &TR) {
  Elapsed    += TR.Elapsed;
  UserTime   += TR.UserTime;
  SystemTime += TR.SystemTime;
  MaxRSS     += TR.MaxRSS;
}

// TimingDtor - Print out information about timing information
TimingInfo::~TimingInfo() {
  // Iterate over all of the data, converting it into the dual of the data map,
  // so that the data is sorted by amount of time taken, instead of pointer.
  //
  std::vector<std::pair<TimeRecord, Pass*> > Data;
  TimeRecord Total;
  for (std::map<Pass*, TimeRecord>::iterator I = TimingData.begin(),
         E = TimingData.end(); I != E; ++I)
    // Throw out results for "grouping" pass managers...
    if (!dynamic_cast<AnalysisResolver*>(I->first)) {
      Data.push_back(std::make_pair(I->second, I->first));
      Total.sum(I->second);
    }
  
  // Sort the data by time as the primary key, in reverse order...
  std::sort(Data.begin(), Data.end(),
            std::greater<std::pair<TimeRecord, Pass*> >());

  // Print out timing header...
  std::cerr << std::string(79, '=') << "\n"
            << "                      ... Pass execution timing report ...\n"
            << std::string(79, '=') << "\n  Total Execution Time: "
            << (Total.UserTime+Total.SystemTime) << " seconds ("
            << Total.Elapsed << " wall clock)\n\n   ---User Time---   "
            << "--System Time--   --User+System--   ---Wall Time---";

  if (Total.MaxRSS)
    std::cerr << " ---Mem---";
  std::cerr << "  --- Pass Name ---\n";

  // Loop through all of the timing data, printing it out...
  for (unsigned i = 0, e = Data.size(); i != e; ++i)
    Data[i].first.print(Data[i].second->getPassName(), Total);

  Total.print("TOTAL", Total);
}


void PMDebug::PrintArgumentInformation(const Pass *P) {
  // Print out passes in pass manager...
  if (const AnalysisResolver *PM = dynamic_cast<const AnalysisResolver*>(P)) {
    for (unsigned i = 0, e = PM->getNumContainedPasses(); i != e; ++i)
      PrintArgumentInformation(PM->getContainedPass(i));

  } else {  // Normal pass.  Print argument information...
    // Print out arguments for registered passes that are _optimizations_
    if (const PassInfo *PI = P->getPassInfo())
      if (PI->getPassType() & PassInfo::Optimization)
        std::cerr << " -" << PI->getPassArgument();
  }
}

void PMDebug::PrintPassInformation(unsigned Depth, const char *Action,
                                   Pass *P, Annotable *V) {
  if (PassDebugging >= Executions) {
    std::cerr << (void*)P << std::string(Depth*2+1, ' ') << Action << " '" 
              << P->getPassName();
    if (V) {
      std::cerr << "' on ";

      if (dynamic_cast<Module*>(V)) {
        std::cerr << "Module\n"; return;
      } else if (Function *F = dynamic_cast<Function*>(V))
        std::cerr << "Function '" << F->getName();
      else if (BasicBlock *BB = dynamic_cast<BasicBlock*>(V))
        std::cerr << "BasicBlock '" << BB->getName();
      else if (Value *Val = dynamic_cast<Value*>(V))
        std::cerr << typeid(*Val).name() << " '" << Val->getName();
    }
    std::cerr << "'...\n";
  }
}

void PMDebug::PrintAnalysisSetInfo(unsigned Depth, const char *Msg,
                                   Pass *P, const std::vector<AnalysisID> &Set){
  if (PassDebugging >= Details && !Set.empty()) {
    std::cerr << (void*)P << std::string(Depth*2+3, ' ') << Msg << " Analyses:";
    for (unsigned i = 0; i != Set.size(); ++i)
      std::cerr << "  " << Set[i]->getPassName();
    std::cerr << "\n";
  }
}

//===----------------------------------------------------------------------===//
// Pass Implementation
//

void Pass::addToPassManager(PassManagerT<Module> *PM, AnalysisUsage &AU) {
  PM->addPass(this, AU);
}

// dumpPassStructure - Implement the -debug-passes=Structure option
void Pass::dumpPassStructure(unsigned Offset) {
  std::cerr << std::string(Offset*2, ' ') << getPassName() << "\n";
}

// getPassName - Use C++ RTTI to get a SOMEWHAT intelligable name for the pass.
//
const char *Pass::getPassName() const {
  if (const PassInfo *PI = getPassInfo())
    return PI->getPassName();
  return typeid(*this).name();
}

// print - Print out the internal state of the pass.  This is called by Analyse
// to print out the contents of an analysis.  Otherwise it is not neccesary to
// implement this method.
//
void Pass::print(std::ostream &O) const {
  O << "Pass::print not implemented for pass: '" << getPassName() << "'!\n";
}

// dump - call print(std::cerr);
void Pass::dump() const {
  print(std::cerr, 0);
}

//===----------------------------------------------------------------------===//
// FunctionPass Implementation
//

// run - On a module, we run this pass by initializing, runOnFunction'ing once
// for every function in the module, then by finalizing.
//
bool FunctionPass::run(Module &M) {
  bool Changed = doInitialization(M);
  
  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
    if (!I->isExternal())      // Passes are not run on external functions!
    Changed |= runOnFunction(*I);
  
  return Changed | doFinalization(M);
}

// run - On a function, we simply initialize, run the function, then finalize.
//
bool FunctionPass::run(Function &F) {
  if (F.isExternal()) return false;// Passes are not run on external functions!

  return doInitialization(*F.getParent()) | runOnFunction(F)
       | doFinalization(*F.getParent());
}

void FunctionPass::addToPassManager(PassManagerT<Module> *PM,
                                    AnalysisUsage &AU) {
  PM->addPass(this, AU);
}

void FunctionPass::addToPassManager(PassManagerT<Function> *PM,
                                    AnalysisUsage &AU) {
  PM->addPass(this, AU);
}

//===----------------------------------------------------------------------===//
// BasicBlockPass Implementation
//

// To run this pass on a function, we simply call runOnBasicBlock once for each
// function.
//
bool BasicBlockPass::runOnFunction(Function &F) {
  bool Changed = false;
  for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
    Changed |= runOnBasicBlock(*I);
  return Changed;
}

// To run directly on the basic block, we initialize, runOnBasicBlock, then
// finalize.
//
bool BasicBlockPass::run(BasicBlock &BB) {
  Module &M = *BB.getParent()->getParent();
  return doInitialization(M) | runOnBasicBlock(BB) | doFinalization(M);
}

void BasicBlockPass::addToPassManager(PassManagerT<Function> *PM,
                                      AnalysisUsage &AU) {
  PM->addPass(this, AU);
}

void BasicBlockPass::addToPassManager(PassManagerT<BasicBlock> *PM,
                                      AnalysisUsage &AU) {
  PM->addPass(this, AU);
}


//===----------------------------------------------------------------------===//
// Pass Registration mechanism
//
static std::map<TypeInfo, PassInfo*> *PassInfoMap = 0;
static std::vector<PassRegistrationListener*> *Listeners = 0;

// getPassInfo - Return the PassInfo data structure that corresponds to this
// pass...
const PassInfo *Pass::getPassInfo() const {
  if (PassInfoCache) return PassInfoCache;
  return lookupPassInfo(typeid(*this));
}

const PassInfo *Pass::lookupPassInfo(const std::type_info &TI) {
  if (PassInfoMap == 0) return 0;
  std::map<TypeInfo, PassInfo*>::iterator I = PassInfoMap->find(TI);
  return (I != PassInfoMap->end()) ? I->second : 0;
}

void RegisterPassBase::registerPass(PassInfo *PI) {
  if (PassInfoMap == 0)
    PassInfoMap = new std::map<TypeInfo, PassInfo*>();

  assert(PassInfoMap->find(PI->getTypeInfo()) == PassInfoMap->end() &&
         "Pass already registered!");
  PIObj = PI;
  PassInfoMap->insert(std::make_pair(TypeInfo(PI->getTypeInfo()), PI));

  // Notify any listeners...
  if (Listeners)
    for (std::vector<PassRegistrationListener*>::iterator
           I = Listeners->begin(), E = Listeners->end(); I != E; ++I)
      (*I)->passRegistered(PI);
}

void RegisterPassBase::unregisterPass(PassInfo *PI) {
  assert(PassInfoMap && "Pass registered but not in map!");
  std::map<TypeInfo, PassInfo*>::iterator I =
    PassInfoMap->find(PI->getTypeInfo());
  assert(I != PassInfoMap->end() && "Pass registered but not in map!");

  // Remove pass from the map...
  PassInfoMap->erase(I);
  if (PassInfoMap->empty()) {
    delete PassInfoMap;
    PassInfoMap = 0;
  }

  // Notify any listeners...
  if (Listeners)
    for (std::vector<PassRegistrationListener*>::iterator
           I = Listeners->begin(), E = Listeners->end(); I != E; ++I)
      (*I)->passUnregistered(PI);

  // Delete the PassInfo object itself...
  delete PI;
}

//===----------------------------------------------------------------------===//
//                  Analysis Group Implementation Code
//===----------------------------------------------------------------------===//

struct AnalysisGroupInfo {
  const PassInfo *DefaultImpl;
  std::set<const PassInfo *> Implementations;
  AnalysisGroupInfo() : DefaultImpl(0) {}
};

static std::map<const PassInfo *, AnalysisGroupInfo> *AnalysisGroupInfoMap = 0;

// RegisterAGBase implementation
//
RegisterAGBase::RegisterAGBase(const std::type_info &Interface,
                               const std::type_info *Pass, bool isDefault)
  : ImplementationInfo(0), isDefaultImplementation(isDefault) {

  InterfaceInfo = const_cast<PassInfo*>(Pass::lookupPassInfo(Interface));
  if (InterfaceInfo == 0) {   // First reference to Interface, add it now.
    InterfaceInfo =   // Create the new PassInfo for the interface...
      new PassInfo("", "", Interface, PassInfo::AnalysisGroup, 0, 0);
    registerPass(InterfaceInfo);
    PIObj = 0;
  }
  assert(InterfaceInfo->getPassType() == PassInfo::AnalysisGroup &&
         "Trying to join an analysis group that is a normal pass!");

  if (Pass) {
    ImplementationInfo = Pass::lookupPassInfo(*Pass);
    assert(ImplementationInfo &&
           "Must register pass before adding to AnalysisGroup!");

    // Lazily allocate to avoid nasty initialization order dependencies
    if (AnalysisGroupInfoMap == 0)
      AnalysisGroupInfoMap = new std::map<const PassInfo *,AnalysisGroupInfo>();

    AnalysisGroupInfo &AGI = (*AnalysisGroupInfoMap)[InterfaceInfo];
    assert(AGI.Implementations.count(ImplementationInfo) == 0 &&
           "Cannot add a pass to the same analysis group more than once!");
    AGI.Implementations.insert(ImplementationInfo);
    if (isDefault) {
      assert(AGI.DefaultImpl == 0 && InterfaceInfo->getNormalCtor() == 0 &&
             "Default implementation for analysis group already specified!");
      assert(ImplementationInfo->getNormalCtor() &&
           "Cannot specify pass as default if it does not have a default ctor");
      AGI.DefaultImpl = ImplementationInfo;
      InterfaceInfo->setNormalCtor(ImplementationInfo->getNormalCtor());
    }
  }
}

void RegisterAGBase::setGroupName(const char *Name) {
  assert(InterfaceInfo->getPassName()[0] == 0 && "Interface Name already set!");
  InterfaceInfo->setPassName(Name);
}

RegisterAGBase::~RegisterAGBase() {
  if (ImplementationInfo) {
    assert(AnalysisGroupInfoMap && "Inserted into map, but map doesn't exist?");
    AnalysisGroupInfo &AGI = (*AnalysisGroupInfoMap)[InterfaceInfo];

    assert(AGI.Implementations.count(ImplementationInfo) &&
           "Pass not a member of analysis group?");

    if (AGI.DefaultImpl == ImplementationInfo)
      AGI.DefaultImpl = 0;
    
    AGI.Implementations.erase(ImplementationInfo);

    // Last member of this analysis group? Unregister PassInfo, delete map entry
    if (AGI.Implementations.empty()) {
      assert(AGI.DefaultImpl == 0 &&
             "Default implementation didn't unregister?");
      AnalysisGroupInfoMap->erase(InterfaceInfo);
      if (AnalysisGroupInfoMap->empty()) {  // Delete map if empty
        delete AnalysisGroupInfoMap;
        AnalysisGroupInfoMap = 0;
      }

      unregisterPass(InterfaceInfo);
    }
  }
}


// findAnalysisGroupMember - Return an iterator pointing to one of the elements
// of Map if there is a pass in Map that is a member of the analysis group for
// the specified AnalysisGroupID.
//
static std::map<const PassInfo*, Pass*>::const_iterator
findAnalysisGroupMember(const PassInfo *AnalysisGroupID,
                        const std::map<const PassInfo*, Pass*> &Map) {
  assert(AnalysisGroupID->getPassType() == PassInfo::AnalysisGroup &&
         "AnalysisGroupID is not an analysis group!");
  assert(AnalysisGroupInfoMap && AnalysisGroupInfoMap->count(AnalysisGroupID) &&
         "Analysis Group does not have any registered members!");

  // Get the set of all known implementations of this analysis group...
  std::set<const PassInfo *> &Impls = 
    (*AnalysisGroupInfoMap)[AnalysisGroupID].Implementations;

  // Scan over available passes, checking to see if any is a valid analysis
  for (std::map<const PassInfo*, Pass*>::const_iterator I = Map.begin(),
         E = Map.end(); I != E; ++I)
    if (Impls.count(I->first))  // This is a valid analysis, return it.
      return I;

  return Map.end();  // Nothing of use found.
}




//===----------------------------------------------------------------------===//
// PassRegistrationListener implementation
//

// PassRegistrationListener ctor - Add the current object to the list of
// PassRegistrationListeners...
PassRegistrationListener::PassRegistrationListener() {
  if (!Listeners) Listeners = new std::vector<PassRegistrationListener*>();
  Listeners->push_back(this);
}

// dtor - Remove object from list of listeners...
PassRegistrationListener::~PassRegistrationListener() {
  std::vector<PassRegistrationListener*>::iterator I =
    std::find(Listeners->begin(), Listeners->end(), this);
  assert(Listeners && I != Listeners->end() &&
         "PassRegistrationListener not registered!");
  Listeners->erase(I);

  if (Listeners->empty()) {
    delete Listeners;
    Listeners = 0;
  }
}

// enumeratePasses - Iterate over the registered passes, calling the
// passEnumerate callback on each PassInfo object.
//
void PassRegistrationListener::enumeratePasses() {
  if (PassInfoMap)
    for (std::map<TypeInfo, PassInfo*>::iterator I = PassInfoMap->begin(),
           E = PassInfoMap->end(); I != E; ++I)
      passEnumerate(I->second);
}