C++ CallGraphNode::addCalledFunction方法代码示例

void CallGraph::addToCallGraph(Function *F) {
  CallGraphNode *Node = getOrInsertFunction(F);

  // If this function has external linkage or has its address taken, anything
  // could call it.
  if (!F->hasLocalLinkage() || F->hasAddressTaken())
    ExternalCallingNode->addCalledFunction(CallSite(), Node);

  // If this function is not defined in this translation unit, it could call
  // anything.
  if (F->isDeclaration() && !F->isIntrinsic())
    Node->addCalledFunction(CallSite(), CallsExternalNode.get());

  // Look for calls by this function.
  for (BasicBlock &BB : *F)
    for (Instruction &I : BB) {
      if (auto CS = CallSite(&I)) {
        const Function *Callee = CS.getCalledFunction();
        if (!Callee || !Intrinsic::isLeaf(Callee->getIntrinsicID()))
          // Indirect calls of intrinsics are not allowed so no need to check.
          // We can be more precise here by using TargetArg returned by
          // Intrinsic::isLeaf.
          Node->addCalledFunction(CS, CallsExternalNode.get());
        else if (!Callee->isIntrinsic())
          Node->addCalledFunction(CS, getOrInsertFunction(Callee));
      }
    }
}

/// UpdateCallGraphAfterInlining - Once we have cloned code over from a callee
/// into the caller, update the specified callgraph to reflect the changes we
/// made.  Note that it's possible that not all code was copied over, so only
/// some edges of the callgraph may remain.
static void UpdateCallGraphAfterInlining(CallSite CS,
                                         Function::iterator FirstNewBlock,
                                         ValueToValueMapTy &VMap,
                                         InlineFunctionInfo &IFI) {
  CallGraph &CG = *IFI.CG;
  const Function *Caller = CS.getInstruction()->getParent()->getParent();
  const Function *Callee = CS.getCalledFunction();
  CallGraphNode *CalleeNode = CG[Callee];
  CallGraphNode *CallerNode = CG[Caller];

  // Since we inlined some uninlined call sites in the callee into the caller,
  // add edges from the caller to all of the callees of the callee.
  CallGraphNode::iterator I = CalleeNode->begin(), E = CalleeNode->end();

  // Consider the case where CalleeNode == CallerNode.
  CallGraphNode::CalledFunctionsVector CallCache;
  if (CalleeNode == CallerNode) {
    CallCache.assign(I, E);
    I = CallCache.begin();
    E = CallCache.end();
  }

  for (; I != E; ++I) {
    const Value *OrigCall = I->first;

    ValueToValueMapTy::iterator VMI = VMap.find(OrigCall);
    // Only copy the edge if the call was inlined!
    if (VMI == VMap.end() || VMI->second == 0)
      continue;
    
    // If the call was inlined, but then constant folded, there is no edge to
    // add.  Check for this case.
    Instruction *NewCall = dyn_cast<Instruction>(VMI->second);
    if (NewCall == 0) continue;

    // Remember that this call site got inlined for the client of
    // InlineFunction.
    IFI.InlinedCalls.push_back(NewCall);

    // It's possible that inlining the callsite will cause it to go from an
    // indirect to a direct call by resolving a function pointer.  If this
    // happens, set the callee of the new call site to a more precise
    // destination.  This can also happen if the call graph node of the caller
    // was just unnecessarily imprecise.
    if (I->second->getFunction() == 0)
      if (Function *F = CallSite(NewCall).getCalledFunction()) {
        // Indirect call site resolved to direct call.
        CallerNode->addCalledFunction(CallSite(NewCall), CG[F]);

        continue;
      }

    CallerNode->addCalledFunction(CallSite(NewCall), I->second);
  }
  
  // Update the call graph by deleting the edge from Callee to Caller.  We must
  // do this after the loop above in case Caller and Callee are the same.
  CallerNode->removeCallEdgeFor(CS);
}

/// UpdateCallGraphAfterInlining - Once we have cloned code over from a callee
/// into the caller, update the specified callgraph to reflect the changes we
/// made.  Note that it's possible that not all code was copied over, so only
/// some edges of the callgraph will be remain.
static void UpdateCallGraphAfterInlining(const Function *Caller,
                                         const Function *Callee,
                                         Function::iterator FirstNewBlock,
                                       DenseMap<const Value*, Value*> &ValueMap,
                                         CallGraph &CG) {
  // Update the call graph by deleting the edge from Callee to Caller
  CallGraphNode *CalleeNode = CG[Callee];
  CallGraphNode *CallerNode = CG[Caller];
  CallerNode->removeCallEdgeTo(CalleeNode);
  
  // Since we inlined some uninlined call sites in the callee into the caller,
  // add edges from the caller to all of the callees of the callee.
  for (CallGraphNode::iterator I = CalleeNode->begin(),
       E = CalleeNode->end(); I != E; ++I) {
    const Instruction *OrigCall = I->first.getInstruction();
    
    DenseMap<const Value*, Value*>::iterator VMI = ValueMap.find(OrigCall);
    // Only copy the edge if the call was inlined!
    if (VMI != ValueMap.end() && VMI->second) {
      // If the call was inlined, but then constant folded, there is no edge to
      // add.  Check for this case.
      if (Instruction *NewCall = dyn_cast<Instruction>(VMI->second))
        CallerNode->addCalledFunction(CallSite::get(NewCall), I->second);
    }
  }
}

void ManualInliner::run(std::vector<Function *>::iterator fbegin, std::vector<Function *>::iterator fend) {
    std::vector<CallGraphNode*> nodes;
    //the inliner requires an up to date callgraph, so we add the functions in the SCC
    //to the callgraph. If needed, we can do this during function creation to make it faster
    for(std::vector<Function *>::iterator fp = fbegin; fp != fend; ++fp) {
        Function * F = *fp;
        CallGraphNode * n = CG->getOrInsertFunction(F);
        for (Function::iterator BB = F->begin(), BBE = F->end(); BB != BBE; ++BB)
            for (BasicBlock::iterator II = BB->begin(), IE = BB->end(); II != IE; ++II) {
                CallSite CS(cast<Value>(II));
                if (CS) {
                    const Function *Callee = CS.getCalledFunction();
                    if (Callee && !Callee->isIntrinsic()) {
                        CallGraphNode * n2 = CG->getOrInsertFunction(Callee);
                        n->addCalledFunction(CS,n2);
                    }
                }
            }
        nodes.push_back(n);
    }
    //create a fake SCC node and manually run the inliner pass on it.
    CallGraphSCC SCC(NULL);
    SCC.initialize(&nodes[0], &nodes[0]+nodes.size());
    SI->runOnSCC(SCC);
    //We optimize the function now, which will invalidate the call graph,
    //removing called functions makes sure that further inlining passes don't attempt to add invalid callsites as inlining candidates
    for(std::vector<Function *>::iterator fp = fbegin; fp != fend; ++fp) {
        CG->getOrInsertFunction(*fp)->removeAllCalledFunctions();
    }

}

  // addToCallGraph - Add a function to the call graph, and link the node to all
  // of the functions that it calls.
  //
  void addToCallGraph(Function *F) {
    CallGraphNode *Node = getOrInsertFunction(F);

    // If this function has external linkage, anything could call it.
    if (!F->hasLocalLinkage()) {
      ExternalCallingNode->addCalledFunction(CallSite(), Node);

      // Found the entry point?
      if (F->getName() == "main") {
        if (Root)    // Found multiple external mains?  Don't pick one.
          Root = ExternalCallingNode;
        else
          Root = Node;          // Found a main, keep track of it!
      }
    }

    // Loop over all of the users of the function, looking for non-call uses.
    for (Value::use_iterator I = F->use_begin(), E = F->use_end(); I != E; ++I)
      if ((!isa<CallInst>(I) && !isa<InvokeInst>(I))
          || !CallSite(cast<Instruction>(I)).isCallee(I)) {
        // Not a call, or being used as a parameter rather than as the callee.
        ExternalCallingNode->addCalledFunction(CallSite(), Node);
        break;
      }

    // If this function is not defined in this translation unit, it could call
    // anything.
    if (F->isDeclaration() && !F->isIntrinsic())
      Node->addCalledFunction(CallSite(), CallsExternalNode);

    // Look for calls by this function.
    for (Function::iterator BB = F->begin(), BBE = F->end(); BB != BBE; ++BB)
      for (BasicBlock::iterator II = BB->begin(), IE = BB->end();
           II != IE; ++II) {
        CallSite CS = CallSite::get(II);
        if (CS.getInstruction() && !isa<DbgInfoIntrinsic>(II)) {
          const Function *Callee = CS.getCalledFunction();
          if (Callee)
            Node->addCalledFunction(CS, getOrInsertFunction(Callee));
          else
            Node->addCalledFunction(CS, CallsExternalNode);
        }
      }
  }

void CallGraph::addToCallGraph(Function *F) {
  CallGraphNode *Node = getOrInsertFunction(F);

  // If this function has external linkage, anything could call it.
  if (!F->hasLocalLinkage()) {
    ExternalCallingNode->addCalledFunction(CallSite(), Node);

    // Found the entry point?
    if (F->getName() == "main") {
      if (Root) // Found multiple external mains?  Don't pick one.
        Root = ExternalCallingNode;
      else
        Root = Node; // Found a main, keep track of it!
    }
  }

  // If this function has its address taken, anything could call it.
  if (F->hasAddressTaken())
    ExternalCallingNode->addCalledFunction(CallSite(), Node);

  // If this function is not defined in this translation unit, it could call
  // anything.
  if (F->isDeclaration() && !F->isIntrinsic())
    Node->addCalledFunction(CallSite(), CallsExternalNode.get());

  // Look for calls by this function.
  for (Function::iterator BB = F->begin(), BBE = F->end(); BB != BBE; ++BB)
    for (BasicBlock::iterator II = BB->begin(), IE = BB->end(); II != IE;
         ++II) {
      CallSite CS(cast<Value>(II));
      if (CS) {
        const Function *Callee = CS.getCalledFunction();
        if (!Callee || !Intrinsic::isLeaf(Callee->getIntrinsicID()))
          // Indirect calls of intrinsics are not allowed so no need to check.
          // We can be more precise here by using TargetArg returned by
          // Intrinsic::isLeaf.
          Node->addCalledFunction(CS, CallsExternalNode.get());
        else if (!Callee->isIntrinsic())
          Node->addCalledFunction(CS, getOrInsertFunction(Callee));
      }
    }
}

Function * StructuredModuleEditor::cloneFunc(Function * Original) {
	if (Original == NULL)
		return NULL;

	ValueMap<const Value*, WeakVH> VMap;

// Creates a clone of the function we are cloning
	Function *Clone = CloneFunction(Original, VMap, false);
	Clone->setName(Original->getName() + "-cloned");

// Adds the clone to the Module
	M->getFunctionList().push_back(Clone);

// Adds the clone to the CFG
	CG->getOrInsertFunction(Clone);

// Adds each of the original function's CFG node's interprocedural out-edges
// to the clone's node. All of the original function's intraprocedural in-edges are redirected to the cloned function.
// The clone will have no interprocedural in-edges as it
// was just created.
	CallGraphNode *CloneNode = CG->getOrInsertFunction(Clone);
	for (Function::iterator BBI = Clone->begin(), BBE = Clone->end();
			BBI != BBE; ++BBI) {
		for (BasicBlock::iterator II = BBI->begin(), IE = BBI->end(); II != IE;
				++II) {
			CallSite CS(cast<Value>(II));
// If this isn't a call, or it is a call to an intrinsic...
			if (!CS || isa<IntrinsicInst>(II))
				continue;

			Function *Callee = CS.getCalledFunction();
			if (Callee == Original) {
				Callee = Clone;
				CS.setCalledFunction(Clone);
			}

			CloneNode->addCalledFunction(CS, CG->getOrInsertFunction(Callee));
		}
	}

	return Clone;
}

/// UpdateCallGraphAfterInlining - Once we have cloned code over from a callee
/// into the caller, update the specified callgraph to reflect the changes we
/// made.  Note that it's possible that not all code was copied over, so only
/// some edges of the callgraph may remain.
static void UpdateCallGraphAfterInlining(CallSite CS,
                                         Function::iterator FirstNewBlock,
                                       DenseMap<const Value*, Value*> &ValueMap,
                                         CallGraph &CG) {
  const Function *Caller = CS.getInstruction()->getParent()->getParent();
  const Function *Callee = CS.getCalledFunction();
  CallGraphNode *CalleeNode = CG[Callee];
  CallGraphNode *CallerNode = CG[Caller];

  // Since we inlined some uninlined call sites in the callee into the caller,
  // add edges from the caller to all of the callees of the callee.
  CallGraphNode::iterator I = CalleeNode->begin(), E = CalleeNode->end();

  // Consider the case where CalleeNode == CallerNode.
  CallGraphNode::CalledFunctionsVector CallCache;
  if (CalleeNode == CallerNode) {
    CallCache.assign(I, E);
    I = CallCache.begin();
    E = CallCache.end();
  }

  for (; I != E; ++I) {
    const Instruction *OrigCall = I->first.getInstruction();

    DenseMap<const Value*, Value*>::iterator VMI = ValueMap.find(OrigCall);
    // Only copy the edge if the call was inlined!
    if (VMI != ValueMap.end() && VMI->second) {
      // If the call was inlined, but then constant folded, there is no edge to
      // add.  Check for this case.
      if (Instruction *NewCall = dyn_cast<Instruction>(VMI->second))
        CallerNode->addCalledFunction(CallSite::get(NewCall), I->second);
    }
  }
  // Update the call graph by deleting the edge from Callee to Caller.  We must
  // do this after the loop above in case Caller and Callee are the same.
  CallerNode->removeCallEdgeFor(CS);
}

//.........这里部分代码省略.........

        // Create the alloca.  If we have TargetData, use nice alignment.
        unsigned Align = 1;
        if (TD) Align = TD->getPrefTypeAlignment(AggTy);
        Value *NewAlloca = new AllocaInst(AggTy, 0, Align, I->getName(),
                                          Caller->begin()->begin());
        // Emit a memcpy.
        const Type *Tys[] = { Type::Int64Ty };
        Function *MemCpyFn = Intrinsic::getDeclaration(Caller->getParent(),
                                                       Intrinsic::memcpy, 
                                                       Tys, 1);
        Value *DestCast = new BitCastInst(NewAlloca, VoidPtrTy, "tmp", TheCall);
        Value *SrcCast = new BitCastInst(*AI, VoidPtrTy, "tmp", TheCall);

        Value *Size;
        if (TD == 0)
          Size = ConstantExpr::getSizeOf(AggTy);
        else
          Size = ConstantInt::get(Type::Int64Ty, TD->getTypeStoreSize(AggTy));

        // Always generate a memcpy of alignment 1 here because we don't know
        // the alignment of the src pointer.  Other optimizations can infer
        // better alignment.
        Value *CallArgs[] = {
          DestCast, SrcCast, Size, ConstantInt::get(Type::Int32Ty, 1)
        };
        CallInst *TheMemCpy =
          CallInst::Create(MemCpyFn, CallArgs, CallArgs+4, "", TheCall);

        // If we have a call graph, update it.
        if (CG) {
          CallGraphNode *MemCpyCGN = CG->getOrInsertFunction(MemCpyFn);
          CallGraphNode *CallerNode = (*CG)[Caller];
          CallerNode->addCalledFunction(TheMemCpy, MemCpyCGN);
        }

        // Uses of the argument in the function should use our new alloca
        // instead.
        ActualArg = NewAlloca;
      }

      ValueMap[I] = ActualArg;
    }

    // We want the inliner to prune the code as it copies.  We would LOVE to
    // have no dead or constant instructions leftover after inlining occurs
    // (which can happen, e.g., because an argument was constant), but we'll be
    // happy with whatever the cloner can do.
    CloneAndPruneFunctionInto(Caller, CalledFunc, ValueMap, Returns, ".i",
                              &InlinedFunctionInfo, TD);

    // Remember the first block that is newly cloned over.
    FirstNewBlock = LastBlock; ++FirstNewBlock;

    // Update the callgraph if requested.
    if (CG)
      UpdateCallGraphAfterInlining(CS, FirstNewBlock, ValueMap, *CG);
  }

  // If there are any alloca instructions in the block that used to be the entry
  // block for the callee, move them to the entry block of the caller.  First
  // calculate which instruction they should be inserted before.  We insert the
  // instructions at the end of the current alloca list.
  //
  {
    BasicBlock::iterator InsertPoint = Caller->begin()->begin();

/// updateCallSites - Update all sites that call F to use NF.
CallGraphNode *SRETPromotion::updateCallSites(Function *F, Function *NF) {
  CallGraph &CG = getAnalysis<CallGraph>();
  SmallVector<Value*, 16> Args;

  // Attributes - Keep track of the parameter attributes for the arguments.
  SmallVector<AttributeWithIndex, 8> ArgAttrsVec;

  // Get a new callgraph node for NF.
  CallGraphNode *NF_CGN = CG.getOrInsertFunction(NF);

  while (!F->use_empty()) {
    CallSite CS(*F->use_begin());
    Instruction *Call = CS.getInstruction();

    const AttrListPtr &PAL = F->getAttributes();
    // Add any return attributes.
    if (Attributes attrs = PAL.getRetAttributes())
      ArgAttrsVec.push_back(AttributeWithIndex::get(0, attrs));

    // Copy arguments, however skip first one.
    CallSite::arg_iterator AI = CS.arg_begin(), AE = CS.arg_end();
    Value *FirstCArg = *AI;
    ++AI;
    // 0th parameter attribute is reserved for return type.
    // 1th parameter attribute is for first 1st sret argument.
    unsigned ParamIndex = 2; 
    while (AI != AE) {
      Args.push_back(*AI); 
      if (Attributes Attrs = PAL.getParamAttributes(ParamIndex))
        ArgAttrsVec.push_back(AttributeWithIndex::get(ParamIndex - 1, Attrs));
      ++ParamIndex;
      ++AI;
    }

    // Add any function attributes.
    if (Attributes attrs = PAL.getFnAttributes())
      ArgAttrsVec.push_back(AttributeWithIndex::get(~0, attrs));
    
    AttrListPtr NewPAL = AttrListPtr::get(ArgAttrsVec.begin(), ArgAttrsVec.end());
    
    // Build new call instruction.
    Instruction *New;
    if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) {
      New = InvokeInst::Create(NF, II->getNormalDest(), II->getUnwindDest(),
                               Args.begin(), Args.end(), "", Call);
      cast<InvokeInst>(New)->setCallingConv(CS.getCallingConv());
      cast<InvokeInst>(New)->setAttributes(NewPAL);
    } else {
      New = CallInst::Create(NF, Args.begin(), Args.end(), "", Call);
      cast<CallInst>(New)->setCallingConv(CS.getCallingConv());
      cast<CallInst>(New)->setAttributes(NewPAL);
      if (cast<CallInst>(Call)->isTailCall())
        cast<CallInst>(New)->setTailCall();
    }
    Args.clear();
    ArgAttrsVec.clear();
    New->takeName(Call);

    // Update the callgraph to know that the callsite has been transformed.
    CallGraphNode *CalleeNode = CG[Call->getParent()->getParent()];
    CalleeNode->removeCallEdgeFor(Call);
    CalleeNode->addCalledFunction(New, NF_CGN);
    
    // Update all users of sret parameter to extract value using extractvalue.
    for (Value::use_iterator UI = FirstCArg->use_begin(), 
           UE = FirstCArg->use_end(); UI != UE; ) {
      User *U2 = *UI++;
      CallInst *C2 = dyn_cast<CallInst>(U2);
      if (C2 && (C2 == Call))
        continue;
      
      GetElementPtrInst *UGEP = cast<GetElementPtrInst>(U2);
      ConstantInt *Idx = cast<ConstantInt>(UGEP->getOperand(2));
      Value *GR = ExtractValueInst::Create(New, Idx->getZExtValue(),
                                           "evi", UGEP);
      while(!UGEP->use_empty()) {
        // isSafeToUpdateAllCallers has checked that all GEP uses are
        // LoadInsts
        LoadInst *L = cast<LoadInst>(*UGEP->use_begin());
        L->replaceAllUsesWith(GR);
        L->eraseFromParent();
      }
      UGEP->eraseFromParent();
      continue;
    }
    Call->eraseFromParent();
  }
  
  return NF_CGN;
}