path: root/lib/VMCore/PassManager.cpp

//===- PassManager.cpp - LLVM Pass Infrastructure Implementation ----------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file was developed by Devang Patel and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the LLVM Pass Manager infrastructure. 
//
//===----------------------------------------------------------------------===//


#include "llvm/PassManager.h"
#include "llvm/Module.h"
#include <vector>
#include <map>

using namespace llvm;

namespace llvm {

/// CommonPassManagerImpl helps pass manager analysis required by
/// the managed passes. It provides methods to add/remove analysis
/// available and query if certain analysis is available or not.
class CommonPassManagerImpl : public Pass {

public:

  /// Return true IFF pass P's required analysis set does not required new
  /// manager.
  bool manageablePass(Pass *P);

  Pass *getAnalysisPass(AnalysisID AID) const {

    std::map<AnalysisID, Pass*>::const_iterator I = 
      AvailableAnalysis.find(AID);

    if (I != AvailableAnalysis.end())
      return NULL;
    else
      return I->second;
  }

  /// Augment RequiredAnalysis by adding analysis required by pass P.
  void noteDownRequiredAnalysis(Pass *P);

  /// Augment AvailableAnalysis by adding analysis made available by pass P.
  void noteDownAvailableAnalysis(Pass *P);

  /// Remove Analysis that is not preserved by the pass
  void removeNotPreservedAnalysis(Pass *P);
  
  /// Remove dead passes
  void removeDeadPasses(Pass *P);

  /// Add pass P into the PassVector. Update RequiredAnalysis and
  /// AvailableAnalysis appropriately if ProcessAnalysis is true.
  void addPassToManager (Pass *P, bool ProcessAnalysis = true);

  /// Clear analysis vectors RequiredAnalysis and AvailableAnalysis.
  /// This is used before running passes managed by the manager.
  void clearAnalysis() { 
    RequiredAnalysis.clear();
    AvailableAnalysis.clear();
    LastUser.clear();
  }

  // All Required analyses should be available to the pass as it runs!  Here
  // we fill in the AnalysisImpls member of the pass so that it can
  // successfully use the getAnalysis() method to retrieve the
  // implementations it needs.
  //
 void initializeAnalysisImpl(Pass *P);

  inline std::vector<Pass *>::iterator passVectorBegin() { 
    return PassVector.begin(); 
  }

  inline std::vector<Pass *>::iterator passVectorEnd() { 
    return PassVector.end();
  }

  inline void setLastUser(Pass *P, Pass *LU) { 
    LastUser[P] = LU; 
    // TODO : Check if pass P is available.

    // Prolong live range of analyses that are needed after an analysis pass
    // is destroyed, for querying by subsequent passes
    AnalysisUsage AnUsage;
    P->getAnalysisUsage(AnUsage);
    const std::vector<AnalysisID> &IDs = AnUsage.getRequiredTransitiveSet();
    for (std::vector<AnalysisID>::const_iterator I = IDs.begin(),
           E = IDs.end(); I != E; ++I) {
      Pass *AnalysisPass = getAnalysisPass(*I); // getAnalysisPassFromManager(*I);
      assert (AnalysisPass && "Analysis pass is not available");
      setLastUser(AnalysisPass, LU);
    }

  }

private:
  // Analysis required by the passes managed by this manager. This information
  // used while selecting pass manager during addPass. If a pass does not
  // preserve any analysis required by other passes managed by current
  // pass manager then new pass manager is used.
  std::vector<AnalysisID> RequiredAnalysis;

  // Set of available Analysis. This information is used while scheduling 
  // pass. If a pass requires an analysis which is not not available then 
  // equired analysis pass is scheduled to run before the pass itself is 
  // scheduled to run.
  std::map<AnalysisID, Pass*> AvailableAnalysis;

  // Map to keep track of last user of the analysis pass.
  // LastUser->second is the last user of Lastuser->first.
  std::map<Pass *, Pass *> LastUser;

  // Collection of pass that are managed by this manager
  std::vector<Pass *> PassVector;
};

/// BasicBlockPassManager_New manages BasicBlockPass. It batches all the
/// pass together and sequence them to process one basic block before
/// processing next basic block.
class BasicBlockPassManager_New : public CommonPassManagerImpl {

public:
  BasicBlockPassManager_New() { }

  /// Add a pass into a passmanager queue. 
  bool addPass(Pass *p);
  
  /// Execute all of the passes scheduled for execution.  Keep track of
  /// whether any of the passes modifies the function, and if so, return true.
  bool runOnFunction(Function &F);

  /// Return true IFF AnalysisID AID is currently available.
  Pass *getAnalysisPassFromManager(AnalysisID AID);

private:
};

/// FunctionPassManagerImpl_New manages FunctionPasses and BasicBlockPassManagers.
/// It batches all function passes and basic block pass managers together and
/// sequence them to process one function at a time before processing next
/// function.
class FunctionPassManagerImpl_New : public CommonPassManagerImpl {
public:
  FunctionPassManagerImpl_New(ModuleProvider *P) { /* TODO */ }
  FunctionPassManagerImpl_New() { 
    activeBBPassManager = NULL;
  }
  ~FunctionPassManagerImpl_New() { /* TODO */ };
 
  /// add - Add a pass to the queue of passes to run.  This passes
  /// ownership of the Pass to the PassManager.  When the
  /// PassManager_X is destroyed, the pass will be destroyed as well, so
  /// there is no need to delete the pass. (TODO delete passes.)
  /// This implies that all passes MUST be allocated with 'new'.
  void add(Pass *P) { /* TODO*/  }

  /// Add pass into the pass manager queue.
  bool addPass(Pass *P);

  /// Execute all of the passes scheduled for execution.  Keep
  /// track of whether any of the passes modifies the function, and if
  /// so, return true.
  bool runOnModule(Module &M);

  /// Return true IFF AnalysisID AID is currently available.
  Pass *getAnalysisPassFromManager(AnalysisID AID);

private:
  // Active Pass Managers
  BasicBlockPassManager_New *activeBBPassManager;
};

/// ModulePassManager_New manages ModulePasses and function pass managers.
/// It batches all Module passes  passes and function pass managers together and
/// sequence them to process one module.
class ModulePassManager_New : public CommonPassManagerImpl {
 
public:
  ModulePassManager_New() { activeFunctionPassManager = NULL; }
  
  /// Add a pass into a passmanager queue. 
  bool addPass(Pass *p);
  
  /// run - Execute all of the passes scheduled for execution.  Keep track of
  /// whether any of the passes modifies the module, and if so, return true.
  bool runOnModule(Module &M);

  /// Return true IFF AnalysisID AID is currently available.
  Pass *getAnalysisPassFromManager(AnalysisID AID);
  
private:
  // Active Pass Manager
  FunctionPassManagerImpl_New *activeFunctionPassManager;
};

/// PassManager_New manages ModulePassManagers
class PassManagerImpl_New : public CommonPassManagerImpl {

public:

  /// add - Add a pass to the queue of passes to run.  This passes ownership of
  /// the Pass to the PassManager.  When the PassManager is destroyed, the pass
  /// will be destroyed as well, so there is no need to delete the pass.  This
  /// implies that all passes MUST be allocated with 'new'.
  void add(Pass *P);
 
  /// run - Execute all of the passes scheduled for execution.  Keep track of
  /// whether any of the passes modifies the module, and if so, return true.
  bool run(Module &M);

  /// Return true IFF AnalysisID AID is currently available.
  Pass *getAnalysisPassFromManager(AnalysisID AID);

private:

  /// Add a pass into a passmanager queue. This is used by schedulePasses
  bool addPass(Pass *p);

  /// Schedule pass P for execution. Make sure that passes required by
  /// P are run before P is run. Update analysis info maintained by
  /// the manager. Remove dead passes. This is a recursive function.
  void schedulePass(Pass *P);

  /// Schedule all passes collected in pass queue using add(). Add all the
  /// schedule passes into various manager's queue using addPass().
  void schedulePasses();

  // Collection of pass managers
  std::vector<ModulePassManager_New *> PassManagers;

  // Active Pass Manager
  ModulePassManager_New *activeManager;
};

} // End of llvm namespace

// CommonPassManagerImpl implementation

/// Return true IFF pass P's required analysis set does not required new
/// manager.
bool CommonPassManagerImpl::manageablePass(Pass *P) {

  AnalysisUsage AnUsage;
  P->getAnalysisUsage(AnUsage);

  // If this pass is not preserving information that is required by the other
  // passes managed by this manager then use new manager
  if (!AnUsage.getPreservesAll()) {
    const std::vector<AnalysisID> &PreservedSet = AnUsage.getPreservedSet();
    for (std::vector<AnalysisID>::iterator</