C++ SCCNodeSet::insert方法代码示例

PreservedAnalyses PostOrderFunctionAttrsPass::run(LazyCallGraph::SCC &C,
                                                  CGSCCAnalysisManager &AM,
                                                  LazyCallGraph &CG,
                                                  CGSCCUpdateResult &) {
  FunctionAnalysisManager &FAM =
      AM.getResult<FunctionAnalysisManagerCGSCCProxy>(C, CG).getManager();

  // We pass a lambda into functions to wire them up to the analysis manager
  // for getting function analyses.
  auto AARGetter = [&](Function &F) -> AAResults & {
    return FAM.getResult<AAManager>(F);
  };

  // Fill SCCNodes with the elements of the SCC. Also track whether there are
  // any external or opt-none nodes that will prevent us from optimizing any
  // part of the SCC.
  SCCNodeSet SCCNodes;
  bool HasUnknownCall = false;
  for (LazyCallGraph::Node &N : C) {
    Function &F = N.getFunction();
    if (F.hasFnAttribute(Attribute::OptimizeNone)) {
      // Treat any function we're trying not to optimize as if it were an
      // indirect call and omit it from the node set used below.
      HasUnknownCall = true;
      continue;
    }
    // Track whether any functions in this SCC have an unknown call edge.
    // Note: if this is ever a performance hit, we can common it with
    // subsequent routines which also do scans over the instructions of the
    // function.
    if (!HasUnknownCall)
      for (Instruction &I : instructions(F))
        if (auto CS = CallSite(&I))
          if (!CS.getCalledFunction()) {
            HasUnknownCall = true;
            break;
          }

    SCCNodes.insert(&F);
  }

  bool Changed = false;
  Changed |= addArgumentReturnedAttrs(SCCNodes);
  Changed |= addReadAttrs(SCCNodes, AARGetter);
  Changed |= addArgumentAttrs(SCCNodes);

  // If we have no external nodes participating in the SCC, we can deduce some
  // more precise attributes as well.
  if (!HasUnknownCall) {
    Changed |= addNoAliasAttrs(SCCNodes);
    Changed |= addNonNullAttrs(SCCNodes);
    Changed |= removeConvergentAttrs(SCCNodes);
    Changed |= addNoRecurseAttrs(SCCNodes);
  }

  return Changed ? PreservedAnalyses::none() : PreservedAnalyses::all();
}

bool PostOrderFunctionAttrsLegacyPass::runOnSCC(CallGraphSCC &SCC) {
  TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
  bool Changed = false;

  // We compute dedicated AA results for each function in the SCC as needed. We
  // use a lambda referencing external objects so that they live long enough to
  // be queried, but we re-use them each time.
  Optional<BasicAAResult> BAR;
  Optional<AAResults> AAR;
  auto AARGetter = [&](Function &F) -> AAResults & {
    BAR.emplace(createLegacyPMBasicAAResult(*this, F));
    AAR.emplace(createLegacyPMAAResults(*this, F, *BAR));
    return *AAR;
  };

  // Fill SCCNodes with the elements of the SCC. Used for quickly looking up
  // whether a given CallGraphNode is in this SCC. Also track whether there are
  // any external or opt-none nodes that will prevent us from optimizing any
  // part of the SCC.
  SCCNodeSet SCCNodes;
  bool ExternalNode = false;
  for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
    Function *F = (*I)->getFunction();
    if (!F || F->hasFnAttribute(Attribute::OptimizeNone)) {
      // External node or function we're trying not to optimize - we both avoid
      // transform them and avoid leveraging information they provide.
      ExternalNode = true;
      continue;
    }

    SCCNodes.insert(F);
  }

  Changed |= addReadAttrs(SCCNodes, AARGetter);
  Changed |= addArgumentAttrs(SCCNodes);

  // If we have no external nodes participating in the SCC, we can deduce some
  // more precise attributes as well.
  if (!ExternalNode) {
    Changed |= addNoAliasAttrs(SCCNodes);
    Changed |= addNonNullAttrs(SCCNodes, *TLI);
    Changed |= removeConvergentAttrs(SCCNodes);
    Changed |= addNoRecurseAttrs(SCCNodes);
  }

  return Changed;
}

static bool runImpl(CallGraphSCC &SCC, AARGetterT AARGetter) {
  bool Changed = false;

  // Fill SCCNodes with the elements of the SCC. Used for quickly looking up
  // whether a given CallGraphNode is in this SCC. Also track whether there are
  // any external or opt-none nodes that will prevent us from optimizing any
  // part of the SCC.
  SCCNodeSet SCCNodes;
  bool ExternalNode = false;
  for (CallGraphNode *I : SCC) {
    Function *F = I->getFunction();
    if (!F || F->hasFnAttribute(Attribute::OptimizeNone)) {
      // External node or function we're trying not to optimize - we both avoid
      // transform them and avoid leveraging information they provide.
      ExternalNode = true;
      continue;
    }

    SCCNodes.insert(F);
  }

  Changed |= addArgumentReturnedAttrs(SCCNodes);
  Changed |= addReadAttrs(SCCNodes, AARGetter);
  Changed |= addArgumentAttrs(SCCNodes);

  // If we have no external nodes participating in the SCC, we can deduce some
  // more precise attributes as well.
  if (!ExternalNode) {
    Changed |= addNoAliasAttrs(SCCNodes);
    Changed |= addNonNullAttrs(SCCNodes);
    Changed |= removeConvergentAttrs(SCCNodes);
    Changed |= addNoRecurseAttrs(SCCNodes);
  }

  return Changed;
}