Ejemplo n.º 1
0
// deleteValue method - This method is used to remove a pointer value from the
// AliasSetTracker entirely.  It should be used when an instruction is deleted
// from the program to update the AST.  If you don't use this, you would have
// dangling pointers to deleted instructions.
//
void AliasSetTracker::deleteValue(Value *PtrVal) {
  // Notify the alias analysis implementation that this value is gone.
  AA.deleteValue(PtrVal);

  // If this is a call instruction, remove the callsite from the appropriate
  // AliasSet (if present).
  if (Instruction *Inst = dyn_cast<Instruction>(PtrVal)) {
    if (Inst->mayReadOrWriteMemory()) {
      // Scan all the alias sets to see if this call site is contained.
      for (iterator I = begin(), E = end(); I != E; ++I) {
        if (I->Forward) continue;
        
        I->removeUnknownInst(Inst);
      }
    }
  }

  // First, look up the PointerRec for this pointer.
  PointerMapType::iterator I = PointerMap.find(PtrVal);
  if (I == PointerMap.end()) return;  // Noop

  // If we found one, remove the pointer from the alias set it is in.
  AliasSet::PointerRec *PtrValEnt = I->second;
  AliasSet *AS = PtrValEnt->getAliasSet(*this);

  // Unlink and delete from the list of values.
  PtrValEnt->eraseFromList();
  
  // Stop using the alias set.
  AS->dropRef(*this);
  
  PointerMap.erase(I);
}
Ejemplo n.º 2
0
/// remove - Remove the specified (potentially non-empty) alias set from the
/// tracker.
void AliasSetTracker::remove(AliasSet &AS) {
  // Drop all call sites.
  AS.UnknownInsts.clear();
  
  // Clear the alias set.
  unsigned NumRefs = 0;
  while (!AS.empty()) {
    AliasSet::PointerRec *P = AS.PtrList;

    Value *ValToRemove = P->getValue();
    
    // Unlink and delete entry from the list of values.
    P->eraseFromList();
    
    // Remember how many references need to be dropped.
    ++NumRefs;

    // Finally, remove the entry.
    PointerMap.erase(ValToRemove);
  }
  
  // Stop using the alias set, removing it.
  AS.RefCount -= NumRefs;
  if (AS.RefCount == 0)
    AS.removeFromTracker(*this);
}
Ejemplo n.º 3
0
// deleteValue method - This method is used to remove a pointer value from the
// AliasSetTracker entirely.  It should be used when an instruction is deleted
// from the program to update the AST.  If you don't use this, you would have
// dangling pointers to deleted instructions.
//
void AliasSetTracker::deleteValue(Value *PtrVal) {
  // Notify the alias analysis implementation that this value is gone.
  AA.deleteValue(PtrVal);

  // If this is a call instruction, remove the callsite from the appropriate
  // AliasSet.
  CallSite CS = CallSite::get(PtrVal);
  if (CS.getInstruction())
    if (!AA.doesNotAccessMemory(CS))
      if (AliasSet *AS = findAliasSetForCallSite(CS))
        AS->removeCallSite(CS);

  // First, look up the PointerRec for this pointer.
  PointerMapType::iterator I = PointerMap.find(PtrVal);
  if (I == PointerMap.end()) return;  // Noop

  // If we found one, remove the pointer from the alias set it is in.
  AliasSet::PointerRec *PtrValEnt = I->second;
  AliasSet *AS = PtrValEnt->getAliasSet(*this);

  // Unlink and delete from the list of values.
  PtrValEnt->eraseFromList();
  
  // Stop using the alias set.
  AS->dropRef(*this);
  
  PointerMap.erase(I);
}
Ejemplo n.º 4
0
// deleteValue method - This method is used to remove a pointer value from the
// AliasSetTracker entirely.  It should be used when an instruction is deleted
// from the program to update the AST.  If you don't use this, you would have
// dangling pointers to deleted instructions.
//
void AliasSetTracker::deleteValue(Value *PtrVal) {
  // First, look up the PointerRec for this pointer.
  PointerMapType::iterator I = PointerMap.find_as(PtrVal);
  if (I == PointerMap.end()) return;  // Noop

  // If we found one, remove the pointer from the alias set it is in.
  AliasSet::PointerRec *PtrValEnt = I->second;
  AliasSet *AS = PtrValEnt->getAliasSet(*this);

  // Unlink and delete from the list of values.
  PtrValEnt->eraseFromList();

  if (AS->Alias == AliasSet::SetMayAlias) {
    AS->SetSize--;
    TotalMayAliasSetSize--;
  }

  // Stop using the alias set.
  AS->dropRef(*this);

  PointerMap.erase(I);
}