[PM/AA] Remove the last relics of the separate IPA library from LLVM, folding the code into the main Analysis library.

[chandlerc]

Summary

There already wasn't much of a distinction between Analysis and IPA.
A number of the passes in Analysis are actually IPA passes, and there
doesn't seem to be any advantage to separating them.

Moreover, it makes it hard to have interactions between analyses that
are both local and interprocedural. In trying to make the Alias Analysis
infrastructure work with the new pass manager, it becomes particularly
awkward to navigate this split.

I've tried to find all the places where we referenced this, but I may
have missed some. I have also adjusted the C API to continue to be
equivalently functional after this change.

[chandlerc]

Dammit, sorry folks.

I had gotten two LGTMs on IRC but neither of them made it here for this patch. I've submitted it now in r245318. Really sorry about that, please shout if this causes you any trouble.

llvm/trunk/bindings/python/llvm/core.py

def register_library(library):
     library.LLVMInitializeIPO.restype = None
 
     library.LLVMInitializeInstrumentation.argtypes = [PassRegistry]
     library.LLVMInitializeInstrumentation.restype = None
 
     library.LLVMInitializeAnalysis.argtypes = [PassRegistry]
     library.LLVMInitializeAnalysis.restype = None
 
-    library.LLVMInitializeIPA.argtypes = [PassRegistry]
-    library.LLVMInitializeIPA.restype = None
-
     library.LLVMInitializeCodeGen.argtypes = [PassRegistry]
     library.LLVMInitializeCodeGen.restype = None
 
     library.LLVMInitializeTarget.argtypes = [PassRegistry]
     library.LLVMInitializeTarget.restype = None
 
     library.LLVMShutdown.argtypes = []
     library.LLVMShutdown.restype = None
def initialize_llvm():
     lib.LLVMInitializeTransformUtils(p)
     lib.LLVMInitializeScalarOpts(p)
     lib.LLVMInitializeObjCARCOpts(p)
     lib.LLVMInitializeVectorization(p)
     lib.LLVMInitializeInstCombine(p)
     lib.LLVMInitializeIPO(p)
     lib.LLVMInitializeInstrumentation(p)
     lib.LLVMInitializeAnalysis(p)
-    lib.LLVMInitializeIPA(p)
     lib.LLVMInitializeCodeGen(p)
     lib.LLVMInitializeTarget(p)
 
 register_library(lib)
 Enums = register_enumerations()
 initialize_llvm()

llvm/trunk/include/llvm/InitializePasses.h

 
 /// initializeInstrumentation - Initialize all passes linked into the
 /// Instrumentation library.
 void initializeInstrumentation(PassRegistry&);
 
 /// initializeAnalysis - Initialize all passes linked into the Analysis library.
 void initializeAnalysis(PassRegistry&);
 
-/// initializeIPA - Initialize all passes linked into the IPA library.
-void initializeIPA(PassRegistry&);
-
 /// initializeCodeGen - Initialize all passes linked into the CodeGen library.
 void initializeCodeGen(PassRegistry&);
 
 /// initializeCodeGen - Initialize all passes linked into the CodeGen library.
 void initializeTarget(PassRegistry&);
 
 void initializeAAEvalPass(PassRegistry&);
 void initializeAddDiscriminatorsPass(PassRegistry&);

llvm/trunk/lib/Analysis/Analysis.cpp

void llvm::initializeAnalysis(PassRegistry &Registry) {
   initializeAliasAnalysisAnalysisGroup(Registry);
   initializeAliasAnalysisCounterPass(Registry);
   initializeAAEvalPass(Registry);
   initializeAliasSetPrinterPass(Registry);
   initializeNoAAPass(Registry);
   initializeBasicAliasAnalysisPass(Registry);
   initializeBlockFrequencyInfoWrapperPassPass(Registry);
   initializeBranchProbabilityInfoWrapperPassPass(Registry);
+  initializeCallGraphWrapperPassPass(Registry);
+  initializeCallGraphPrinterPass(Registry);
+  initializeCallGraphViewerPass(Registry);
   initializeCostModelAnalysisPass(Registry);
   initializeCFGViewerPass(Registry);
   initializeCFGPrinterPass(Registry);
   initializeCFGOnlyViewerPass(Registry);
   initializeCFGOnlyPrinterPass(Registry);
   initializeCFLAliasAnalysisPass(Registry);
   initializeDependenceAnalysisPass(Registry);
   initializeDelinearizationPass(Registry);
   initializeDemandedBitsPass(Registry);
   initializeDivergenceAnalysisPass(Registry);
   initializeDominanceFrontierPass(Registry);
   initializeDomViewerPass(Registry);
   initializeDomPrinterPass(Registry);
   initializeDomOnlyViewerPass(Registry);
   initializePostDomViewerPass(Registry);
   initializeDomOnlyPrinterPass(Registry);
   initializePostDomPrinterPass(Registry);
   initializePostDomOnlyViewerPass(Registry);
   initializePostDomOnlyPrinterPass(Registry);
+  initializeGlobalsModRefPass(Registry);
   initializeIVUsersPass(Registry);
   initializeInstCountPass(Registry);
   initializeIntervalPartitionPass(Registry);
   initializeLazyValueInfoPass(Registry);
   initializeLintPass(Registry);
   initializeLoopInfoWrapperPassPass(Registry);
   initializeMemDepPrinterPass(Registry);
   initializeMemDerefPrinterPass(Registry);
void llvm::initializeAnalysis(PassRegistry &Registry) {
   initializeTypeBasedAliasAnalysisPass(Registry);
   initializeScopedNoAliasAAPass(Registry);
 }
 
 void LLVMInitializeAnalysis(LLVMPassRegistryRef R) {
   initializeAnalysis(*unwrap(R));
 }
 
+void LLVMInitializeIPA(LLVMPassRegistryRef R) {
+  initializeAnalysis(*unwrap(R));
+}
+
 LLVMBool LLVMVerifyModule(LLVMModuleRef M, LLVMVerifierFailureAction Action,
                           char **OutMessages) {
   raw_ostream *DebugOS = Action != LLVMReturnStatusAction ? &errs() : nullptr;
   std::string Messages;
   raw_string_ostream MsgsOS(Messages);
 
   LLVMBool Result = verifyModule(*unwrap(M), OutMessages ? &MsgsOS : DebugOS);
 

llvm/trunk/lib/Analysis/CMakeLists.txt

 add_llvm_library(LLVMAnalysis
   AliasAnalysis.cpp
   AliasAnalysisCounter.cpp
   AliasAnalysisEvaluator.cpp
   AliasSetTracker.cpp
   Analysis.cpp
   AssumptionCache.cpp
   BasicAliasAnalysis.cpp
   BlockFrequencyInfo.cpp
   BlockFrequencyInfoImpl.cpp
   BranchProbabilityInfo.cpp
   CFG.cpp
   CFGPrinter.cpp
   CFLAliasAnalysis.cpp
   CGSCCPassManager.cpp
+  CallGraph.cpp
+  CallGraphSCCPass.cpp
+  CallPrinter.cpp
   CaptureTracking.cpp
   CostModel.cpp
   CodeMetrics.cpp
   ConstantFolding.cpp
   Delinearization.cpp
   DemandedBits.cpp
   DependenceAnalysis.cpp
   DivergenceAnalysis.cpp
   DomPrinter.cpp
   DominanceFrontier.cpp
+  GlobalsModRef.cpp
   IVUsers.cpp
+  InlineCost.cpp
   InstCount.cpp
   InstructionSimplify.cpp
   Interval.cpp
   IntervalPartition.cpp
   IteratedDominanceFrontier.cpp
   LazyCallGraph.cpp
   LazyValueInfo.cpp
   LibCallSemantics.cpp
add_llvm_library(LLVMAnalysis
   ValueTracking.cpp
   VectorUtils.cpp
 
   ADDITIONAL_HEADER_DIRS
   ${LLVM_MAIN_INCLUDE_DIR}/llvm/Analysis
   )
 
 add_dependencies(LLVMAnalysis intrinsics_gen)
-
-add_subdirectory(IPA)

llvm/trunk/lib/Analysis/CallGraph.cpp

+//===- CallGraph.cpp - Build a Module's call graph ------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/CallGraph.h"
+#include "llvm/IR/CallSite.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// Implementations of the CallGraph class methods.
+//
+
+CallGraph::CallGraph(Module &M)
+    : M(M), Root(nullptr), ExternalCallingNode(getOrInsertFunction(nullptr)),
+      CallsExternalNode(llvm::make_unique<CallGraphNode>(nullptr)) {
+  // Add every function to the call graph.
+  for (Function &F : M)
+    addToCallGraph(&F);
+
+  // If we didn't find a main function, use the external call graph node
+  if (!Root)
+    Root = ExternalCallingNode;
+}
+
+CallGraph::CallGraph(CallGraph &&Arg)
+    : M(Arg.M), FunctionMap(std::move(Arg.FunctionMap)), Root(Arg.Root),
+      ExternalCallingNode(Arg.ExternalCallingNode),
+      CallsExternalNode(std::move(Arg.CallsExternalNode)) {
+  Arg.FunctionMap.clear();
+  Arg.Root = nullptr;
+  Arg.ExternalCallingNode = nullptr;
+}
+
+CallGraph::~CallGraph() {
+  // CallsExternalNode is not in the function map, delete it explicitly.
+  if (CallsExternalNode)
+    CallsExternalNode->allReferencesDropped();
+
+// Reset all node's use counts to zero before deleting them to prevent an
+// assertion from firing.
+#ifndef NDEBUG
+  for (auto &I : FunctionMap)
+    I.second->allReferencesDropped();
+#endif
+}
+
+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));
+      }
+    }
+}
+
+void CallGraph::print(raw_ostream &OS) const {
+  OS << "CallGraph Root is: ";
+  if (Function *F = Root->getFunction())
+    OS << F->getName() << "\n";
+  else {
+    OS << "<<null function: 0x" << Root << ">>\n";
+  }
+
+  // Print in a deterministic order by sorting CallGraphNodes by name.  We do
+  // this here to avoid slowing down the non-printing fast path.
+
+  SmallVector<CallGraphNode *, 16> Nodes;
+  Nodes.reserve(FunctionMap.size());
+
+  for (auto I = begin(), E = end(); I != E; ++I)
+    Nodes.push_back(I->second.get());
+
+  std::sort(Nodes.begin(), Nodes.end(),
+            [](CallGraphNode *LHS, CallGraphNode *RHS) {
+    if (Function *LF = LHS->getFunction())
+      if (Function *RF = RHS->getFunction())
+        return LF->getName() < RF->getName();
+
+    return RHS->getFunction() != nullptr;
+  });
+
+  for (CallGraphNode *CN : Nodes)
+    CN->print(OS);
+}
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+void CallGraph::dump() const { print(dbgs()); }
+#endif
+
+// removeFunctionFromModule - Unlink the function from this module, returning
+// it.  Because this removes the function from the module, the call graph node
+// is destroyed.  This is only valid if the function does not call any other
+// functions (ie, there are no edges in it's CGN).  The easiest way to do this
+// is to dropAllReferences before calling this.
+//
+Function *CallGraph::removeFunctionFromModule(CallGraphNode *CGN) {
+  assert(CGN->empty() && "Cannot remove function from call "
+         "graph if it references other functions!");
+  Function *F = CGN->getFunction(); // Get the function for the call graph node
+  FunctionMap.erase(F);             // Remove the call graph node from the map
+
+  M.getFunctionList().remove(F);
+  return F;
+}
+
+/// spliceFunction - Replace the function represented by this node by another.
+/// This does not rescan the body of the function, so it is suitable when
+/// splicing the body of the old function to the new while also updating all
+/// callers from old to new.
+///
+void CallGraph::spliceFunction(const Function *From, const Function *To) {
+  assert(FunctionMap.count(From) && "No CallGraphNode for function!");
+  assert(!FunctionMap.count(To) &&
+         "Pointing CallGraphNode at a function that already exists");
+  FunctionMapTy::iterator I = FunctionMap.find(From);
+  I->second->F = const_cast<Function*>(To);
+  FunctionMap[To] = std::move(I->second);
+  FunctionMap.erase(I);
+}
+
+// getOrInsertFunction - This method is identical to calling operator[], but
+// it will insert a new CallGraphNode for the specified function if one does
+// not already exist.
+CallGraphNode *CallGraph::getOrInsertFunction(const Function *F) {
+  auto &CGN = FunctionMap[F];
+  if (CGN)
+    return CGN.get();
+
+  assert((!F || F->getParent() == &M) && "Function not in current module!");
+  CGN = llvm::make_unique<CallGraphNode>(const_cast<Function *>(F));
+  return CGN.get();
+}
+
+//===----------------------------------------------------------------------===//
+// Implementations of the CallGraphNode class methods.
+//
+
+void CallGraphNode::print(raw_ostream &OS) const {
+  if (Function *F = getFunction())
+    OS << "Call graph node for function: '" << F->getName() << "'";
+  else
+    OS << "Call graph node <<null function>>";
+  
+  OS << "<<" << this << ">>  #uses=" << getNumReferences() << '\n';
+
+  for (const_iterator I = begin(), E = end(); I != E; ++I) {
+    OS << "  CS<" << I->first << "> calls ";
+    if (Function *FI = I->second->getFunction())
+      OS << "function '" << FI->getName() <<"'\n";
+    else
+      OS << "external node\n";
+  }
+  OS << '\n';
+}
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+void CallGraphNode::dump() const { print(dbgs()); }
+#endif
+
+/// removeCallEdgeFor - This method removes the edge in the node for the
+/// specified call site.  Note that this method takes linear time, so it
+/// should be used sparingly.
+void CallGraphNode::removeCallEdgeFor(CallSite CS) {
+  for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
+    assert(I != CalledFunctions.end() && "Cannot find callsite to remove!");
+    if (I->first == CS.getInstruction()) {
+      I->second->DropRef();
+      *I = CalledFunctions.back();
+      CalledFunctions.pop_back();
+      return;
+    }
+  }
+}
+
+// removeAnyCallEdgeTo - This method removes any call edges from this node to
+// the specified callee function.  This takes more time to execute than
+// removeCallEdgeTo, so it should not be used unless necessary.
+void CallGraphNode::removeAnyCallEdgeTo(CallGraphNode *Callee) {
+  for (unsigned i = 0, e = CalledFunctions.size(); i != e; ++i)
+    if (CalledFunctions[i].second == Callee) {
+      Callee->DropRef();
+      CalledFunctions[i] = CalledFunctions.back();
+      CalledFunctions.pop_back();
+      --i; --e;
+    }
+}
+
+/// removeOneAbstractEdgeTo - Remove one edge associated with a null callsite
+/// from this node to the specified callee function.
+void CallGraphNode::removeOneAbstractEdgeTo(CallGraphNode *Callee) {
+  for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
+    assert(I != CalledFunctions.end() && "Cannot find callee to remove!");
+    CallRecord &CR = *I;
+    if (CR.second == Callee && CR.first == nullptr) {
+      Callee->DropRef();
+      *I = CalledFunctions.back();
+      CalledFunctions.pop_back();
+      return;
+    }
+  }
+}
+
+/// replaceCallEdge - This method replaces the edge in the node for the
+/// specified call site with a new one.  Note that this method takes linear
+/// time, so it should be used sparingly.
+void CallGraphNode::replaceCallEdge(CallSite CS,
+                                    CallSite NewCS, CallGraphNode *NewNode){
+  for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
+    assert(I != CalledFunctions.end() && "Cannot find callsite to remove!");
+    if (I->first == CS.getInstruction()) {
+      I->second->DropRef();
+      I->first = NewCS.getInstruction();
+      I->second = NewNode;
+      NewNode->AddRef();
+      return;
+    }
+  }
+}
+
+//===----------------------------------------------------------------------===//
+// Out-of-line definitions of CallGraphAnalysis class members.
+//
+
+char CallGraphAnalysis::PassID;
+
+//===----------------------------------------------------------------------===//
+// Implementations of the CallGraphWrapperPass class methods.
+//
+
+CallGraphWrapperPass::CallGraphWrapperPass() : ModulePass(ID) {
+  initializeCallGraphWrapperPassPass(*PassRegistry::getPassRegistry());
+}
+
+CallGraphWrapperPass::~CallGraphWrapperPass() {}
+
+void CallGraphWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.setPreservesAll();
+}
+
+bool CallGraphWrapperPass::runOnModule(Module &M) {
+  // All the real work is done in the constructor for the CallGraph.
+  G.reset(new CallGraph(M));
+  return false;
+}
+
+INITIALIZE_PASS(CallGraphWrapperPass, "basiccg", "CallGraph Construction",
+                false, true)
+
+char CallGraphWrapperPass::ID = 0;
+
+void CallGraphWrapperPass::releaseMemory() { G.reset(); }
+
+void CallGraphWrapperPass::print(raw_ostream &OS, const Module *) const {
+  if (!G) {
+    OS << "No call graph has been built!\n";
+    return;
+  }
+
+  // Just delegate.
+  G->print(OS);
+}
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+void CallGraphWrapperPass::dump() const { print(dbgs(), nullptr); }
+#endif

llvm/trunk/lib/Analysis/CallGraphSCCPass.cpp

+//===- CallGraphSCCPass.cpp - Pass that operates BU on call graph ---------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the CallGraphSCCPass class, which is used for passes
+// which are implemented as bottom-up traversals on the call graph.  Because
+// there may be cycles in the call graph, passes of this type operate on the
+// call-graph in SCC order: that is, they process function bottom-up, except for
+// recursive functions, which they process all at once.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/CallGraphSCCPass.h"
+#include "llvm/ADT/SCCIterator.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/CallGraph.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/LegacyPassManagers.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/Timer.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+#define DEBUG_TYPE "cgscc-passmgr"
+
+static cl::opt<unsigned> 
+MaxIterations("max-cg-scc-iterations", cl::ReallyHidden, cl::init(4));
+
+STATISTIC(MaxSCCIterations, "Maximum CGSCCPassMgr iterations on one SCC");
+
+//===----------------------------------------------------------------------===//
+// CGPassManager
+//
+/// CGPassManager manages FPPassManagers and CallGraphSCCPasses.
+
+namespace {
+
+class CGPassManager : public ModulePass, public PMDataManager {
+public:
+  static char ID;
+  explicit CGPassManager() 
+    : ModulePass(ID), PMDataManager() { }
+
+  /// 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) override;
+
+  using ModulePass::doInitialization;
+  using ModulePass::doFinalization;
+
+  bool doInitialization(CallGraph &CG);
+  bool doFinalization(CallGraph &CG);
+
+  /// Pass Manager itself does not invalidate any analysis info.
+  void getAnalysisUsage(AnalysisUsage &Info) const override {
+    // CGPassManager walks SCC and it needs CallGraph.
+    Info.addRequired<CallGraphWrapperPass>();
+    Info.setPreservesAll();
+  }
+
+  const char *getPassName() const override {
+    return "CallGraph Pass Manager";
+  }
+
+  PMDataManager *getAsPMDataManager() override { return this; }
+  Pass *getAsPass() override { return this; }
+
+  // Print passes managed by this manager
+  void dumpPassStructure(unsigned Offset) override {
+    errs().indent(Offset*2) << "Call Graph SCC Pass Manager\n";
+    for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
+      Pass *P = getContainedPass(Index);
+      P->dumpPassStructure(Offset + 1);
+      dumpLastUses(P, Offset+1);
+    }
+  }
+
+  Pass *getContainedPass(unsigned N) {
+    assert(N < PassVector.size() && "Pass number out of range!");
+    return static_cast<Pass *>(PassVector[N]);
+  }
+
+  PassManagerType getPassManagerType() const override {
+    return PMT_CallGraphPassManager; 
+  }
+  
+private:
+  bool RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG,
+                         bool &DevirtualizedCall);
+  
+  bool RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC,
+                    CallGraph &CG, bool &CallGraphUpToDate,
+                    bool &DevirtualizedCall);
+  bool RefreshCallGraph(CallGraphSCC &CurSCC, CallGraph &CG,
+                        bool IsCheckingMode);
+};
+
+} // end anonymous namespace.
+
+char CGPassManager::ID = 0;
+
+
+bool CGPassManager::RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC,
+                                 CallGraph &CG, bool &CallGraphUpToDate,
+                                 bool &DevirtualizedCall) {
+  bool Changed = false;
+  PMDataManager *PM = P->getAsPMDataManager();
+
+  if (!PM) {
+    CallGraphSCCPass *CGSP = (CallGraphSCCPass*)P;
+    if (!CallGraphUpToDate) {
+      DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false);
+      CallGraphUpToDate = true;
+    }
+
+    {
+      TimeRegion PassTimer(getPassTimer(CGSP));
+      Changed = CGSP->runOnSCC(CurSCC);
+    }
+    
+    // After the CGSCCPass is done, when assertions are enabled, use
+    // RefreshCallGraph to verify that the callgraph was correctly updated.
+#ifndef NDEBUG
+    if (Changed)
+      RefreshCallGraph(CurSCC, CG, true);
+#endif
+    
+    return Changed;
+  }
+  
+  
+  assert(PM->getPassManagerType() == PMT_FunctionPassManager &&
+         "Invalid CGPassManager member");
+  FPPassManager *FPP = (FPPassManager*)P;
+  
+  // Run pass P on all functions in the current SCC.
+  for (CallGraphNode *CGN : CurSCC) {
+    if (Function *F = CGN->getFunction()) {
+      dumpPassInfo(P, EXECUTION_MSG, ON_FUNCTION_MSG, F->getName());
+      {
+        TimeRegion PassTimer(getPassTimer(FPP));
+        Changed |= FPP->runOnFunction(*F);
+      }
+      F->getContext().yield();
+    }
+  }
+  
+  // The function pass(es) modified the IR, they may have clobbered the
+  // callgraph.
+  if (Changed && CallGraphUpToDate) {
+    DEBUG(dbgs() << "CGSCCPASSMGR: Pass Dirtied SCC: "
+                 << P->getPassName() << '\n');
+    CallGraphUpToDate = false;
+  }
+  return Changed;
+}
+
+
+/// Scan the functions in the specified CFG and resync the
+/// callgraph with the call sites found in it.  This is used after
+/// FunctionPasses have potentially munged the callgraph, and can be used after
+/// CallGraphSCC passes to verify that they correctly updated the callgraph.
+///
+/// This function returns true if it devirtualized an existing function call,
+/// meaning it turned an indirect call into a direct call.  This happens when
+/// a function pass like GVN optimizes away stuff feeding the indirect call.
+/// This never happens in checking mode.
+///
+bool CGPassManager::RefreshCallGraph(CallGraphSCC &CurSCC,
+                                     CallGraph &CG, bool CheckingMode) {
+  DenseMap<Value*, CallGraphNode*> CallSites;
+  
+  DEBUG(dbgs() << "CGSCCPASSMGR: Refreshing SCC with " << CurSCC.size()
+               << " nodes:\n";
+        for (CallGraphNode *CGN : CurSCC)
+          CGN->dump();
+        );
+
+  bool MadeChange = false;
+  bool DevirtualizedCall = false;
+  
+  // Scan all functions in the SCC.
+  unsigned FunctionNo = 0;
+  for (CallGraphSCC::iterator SCCIdx = CurSCC.begin(), E = CurSCC.end();
+       SCCIdx != E; ++SCCIdx, ++FunctionNo) {
+    CallGraphNode *CGN = *SCCIdx;
+    Function *F = CGN->getFunction();
+    if (!F || F->isDeclaration()) continue;
+    
+    // Walk the function body looking for call sites.  Sync up the call sites in
+    // CGN with those actually in the function.
+
+    // Keep track of the number of direct and indirect calls that were
+    // invalidated and removed.
+    unsigned NumDirectRemoved = 0, NumIndirectRemoved = 0;
+    
+    // Get the set of call sites currently in the function.
+    for (CallGraphNode::iterator I = CGN->begin(), E = CGN->end(); I != E; ) {
+      // If this call site is null, then the function pass deleted the call
+      // entirely and the WeakVH nulled it out.  
+      if (!I->first ||
+          // If we've already seen this call site, then the FunctionPass RAUW'd
+          // one call with another, which resulted in two "uses" in the edge
+          // list of the same call.
+          CallSites.count(I->first) ||
+
+          // If the call edge is not from a call or invoke, or it is a
+          // instrinsic call, then the function pass RAUW'd a call with 
+          // another value. This can happen when constant folding happens
+          // of well known functions etc.
+          !CallSite(I->first) ||
+          (CallSite(I->first).getCalledFunction() &&
+           CallSite(I->first).getCalledFunction()->isIntrinsic() &&
+           Intrinsic::isLeaf(
+               CallSite(I->first).getCalledFunction()->getIntrinsicID()))) {
+        assert(!CheckingMode &&
+               "CallGraphSCCPass did not update the CallGraph correctly!");
+        
+        // If this was an indirect call site, count it.
+        if (!I->second->getFunction())
+          ++NumIndirectRemoved;
+        else 
+          ++NumDirectRemoved;
+        
+        // Just remove the edge from the set of callees, keep track of whether
+        // I points to the last element of the vector.
+        bool WasLast = I + 1 == E;
+        CGN->removeCallEdge(I);
+        
+        // If I pointed to the last element of the vector, we have to bail out:
+        // iterator checking rejects comparisons of the resultant pointer with
+        // end.
+        if (WasLast)
+          break;
+        E = CGN->end();
+        continue;
+      }
+      
+      assert(!CallSites.count(I->first) &&
+             "Call site occurs in node multiple times");
+      
+      CallSite CS(I->first);
+      if (CS) {
+        Function *Callee = CS.getCalledFunction();
+        // Ignore intrinsics because they're not really function calls.
+        if (!Callee || !(Callee->isIntrinsic()))
+          CallSites.insert(std::make_pair(I->first, I->second));
+      }
+      ++I;
+    }
+    
+    // Loop over all of the instructions in the function, getting the callsites.
+    // Keep track of the number of direct/indirect calls added.
+    unsigned NumDirectAdded = 0, NumIndirectAdded = 0;
+    
+    for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
+      for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
+        CallSite CS(cast<Value>(I));
+        if (!CS) continue;
+        Function *Callee = CS.getCalledFunction();
+        if (Callee && Callee->isIntrinsic()) continue;
+        
+        // If this call site already existed in the callgraph, just verify it
+        // matches up to expectations and remove it from CallSites.
+        DenseMap<Value*, CallGraphNode*>::iterator ExistingIt =
+          CallSites.find(CS.getInstruction());
+        if (ExistingIt != CallSites.end()) {
+          CallGraphNode *ExistingNode = ExistingIt->second;
+
+          // Remove from CallSites since we have now seen it.
+          CallSites.erase(ExistingIt);
+          
+          // Verify that the callee is right.
+          if (ExistingNode->getFunction() == CS.getCalledFunction())
+            continue;
+          
+          // If we are in checking mode, we are not allowed to actually mutate
+          // the callgraph.  If this is a case where we can infer that the
+          // callgraph is less precise than it could be (e.g. an indirect call
+          // site could be turned direct), don't reject it in checking mode, and
+          // don't tweak it to be more precise.
+          if (CheckingMode && CS.getCalledFunction() &&
+              ExistingNode->getFunction() == nullptr)
+            continue;
+          
+          assert(!CheckingMode &&
+                 "CallGraphSCCPass did not update the CallGraph correctly!");
+          
+          // If not, we either went from a direct call to indirect, indirect to
+          // direct, or direct to different direct.
+          CallGraphNode *CalleeNode;
+          if (Function *Callee = CS.getCalledFunction()) {
+            CalleeNode = CG.getOrInsertFunction(Callee);
+            // Keep track of whether we turned an indirect call into a direct
+            // one.
+            if (!ExistingNode->getFunction()) {
+              DevirtualizedCall = true;
+              DEBUG(dbgs() << "  CGSCCPASSMGR: Devirtualized call to '"
+                           << Callee->getName() << "'\n");
+            }
+          } else {
+            CalleeNode = CG.getCallsExternalNode();
+          }
+
+          // Update the edge target in CGN.
+          CGN->replaceCallEdge(CS, CS, CalleeNode);
+          MadeChange = true;
+          continue;
+        }
+        
+        assert(!CheckingMode &&
+               "CallGraphSCCPass did not update the CallGraph correctly!");
+
+        // If the call site didn't exist in the CGN yet, add it.
+        CallGraphNode *CalleeNode;
+        if (Function *Callee = CS.getCalledFunction()) {
+          CalleeNode = CG.getOrInsertFunction(Callee);
+          ++NumDirectAdded;
+        } else {
+          CalleeNode = CG.getCallsExternalNode();
+          ++NumIndirectAdded;
+        }
+        
+        CGN->addCalledFunction(CS, CalleeNode);
+        MadeChange = true;
+      }
+    
+    // We scanned the old callgraph node, removing invalidated call sites and
+    // then added back newly found call sites.  One thing that can happen is
+    // that an old indirect call site was deleted and replaced with a new direct
+    // call.  In this case, we have devirtualized a call, and CGSCCPM would like
+    // to iteratively optimize the new code.  Unfortunately, we don't really
+    // have a great way to detect when this happens.  As an approximation, we
+    // just look at whether the number of indirect calls is reduced and the
+    // number of direct calls is increased.  There are tons of ways to fool this
+    // (e.g. DCE'ing an indirect call and duplicating an unrelated block with a
+    // direct call) but this is close enough.
+    if (NumIndirectRemoved > NumIndirectAdded &&
+        NumDirectRemoved < NumDirectAdded)
+      DevirtualizedCall = true;
+    
+    // After scanning this function, if we still have entries in callsites, then
+    // they are dangling pointers.  WeakVH should save us for this, so abort if
+    // this happens.
+    assert(CallSites.empty() && "Dangling pointers found in call sites map");
+    
+    // Periodically do an explicit clear to remove tombstones when processing
+    // large scc's.
+    if ((FunctionNo & 15) == 15)
+      CallSites.clear();
+  }
+
+  DEBUG(if (MadeChange) {
+          dbgs() << "CGSCCPASSMGR: Refreshed SCC is now:\n";
+          for (CallGraphNode *CGN : CurSCC)
+            CGN->dump();
+          if (DevirtualizedCall)
+            dbgs() << "CGSCCPASSMGR: Refresh devirtualized a call!\n";
+
+         } else {
+           dbgs() << "CGSCCPASSMGR: SCC Refresh didn't change call graph.\n";
+         }
+        );
+  (void)MadeChange;
+
+  return DevirtualizedCall;
+}
+
+/// Execute the body of the entire pass manager on the specified SCC.
+/// This keeps track of whether a function pass devirtualizes
+/// any calls and returns it in DevirtualizedCall.
+bool CGPassManager::RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG,
+                                      bool &DevirtualizedCall) {
+  bool Changed = false;
+  
+  // Keep track of whether the callgraph is known to be up-to-date or not.
+  // The CGSSC pass manager runs two types of passes:
+  // CallGraphSCC Passes and other random function passes.  Because other
+  // random function passes are not CallGraph aware, they may clobber the
+  // call graph by introducing new calls or deleting other ones.  This flag
+  // is set to false when we run a function pass so that we know to clean up
+  // the callgraph when we need to run a CGSCCPass again.
+  bool CallGraphUpToDate = true;
+
+  // Run all passes on current SCC.
+  for (unsigned PassNo = 0, e = getNumContainedPasses();
+       PassNo != e; ++PassNo) {
+    Pass *P = getContainedPass(PassNo);
+    
+    // If we're in -debug-pass=Executions mode, construct the SCC node list,
+    // otherwise avoid constructing this string as it is expensive.
+    if (isPassDebuggingExecutionsOrMore()) {
+      std::string Functions;
+  #ifndef NDEBUG
+      raw_string_ostream OS(Functions);
+      for (CallGraphSCC::iterator I = CurSCC.begin(), E = CurSCC.end();
+           I != E; ++I) {
+        if (I != CurSCC.begin()) OS << ", ";
+        (*I)->print(OS);
+      }
+      OS.flush();
+  #endif
+      dumpPassInfo(P, EXECUTION_MSG, ON_CG_MSG, Functions);
+    }
+    dumpRequiredSet(P);
+    
+    initializeAnalysisImpl(P);
+    
+    // Actually run this pass on the current SCC.
+    Changed |= RunPassOnSCC(P, CurSCC, CG,
+                            CallGraphUpToDate, DevirtualizedCall);
+    
+    if (Changed)
+      dumpPassInfo(P, MODIFICATION_MSG, ON_CG_MSG, "");
+    dumpPreservedSet(P);
+    
+    verifyPreservedAnalysis(P);      
+    removeNotPreservedAnalysis(P);
+    recordAvailableAnalysis(P);
+    removeDeadPasses(P, "", ON_CG_MSG);
+  }
+  
+  // If the callgraph was left out of date (because the last pass run was a
+  // functionpass), refresh it before we move on to the next SCC.
+  if (!CallGraphUpToDate)
+    DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false);
+  return Changed;
+}
+
+/// 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 CGPassManager::runOnModule(Module &M) {
+  CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
+  bool Changed = doInitialization(CG);
+  
+  // Walk the callgraph in bottom-up SCC order.
+  scc_iterator<CallGraph*> CGI = scc_begin(&CG);
+
+  CallGraphSCC CurSCC(&CGI);
+  while (!CGI.isAtEnd()) {
+    // Copy the current SCC and increment past it so that the pass can hack
+    // on the SCC if it wants to without invalidating our iterator.
+    const std::vector<CallGraphNode *> &NodeVec = *CGI;
+    CurSCC.initialize(NodeVec.data(), NodeVec.data() + NodeVec.size());
+    ++CGI;
+
+    // At the top level, we run all the passes in this pass manager on the
+    // functions in this SCC.  However, we support iterative compilation in the
+    // case where a function pass devirtualizes a call to a function.  For
+    // example, it is very common for a function pass (often GVN or instcombine)
+    // to eliminate the addressing that feeds into a call.  With that improved
+    // information, we would like the call to be an inline candidate, infer
+    // mod-ref information etc.
+    //
+    // Because of this, we allow iteration up to a specified iteration count.
+    // This only happens in the case of a devirtualized call, so we only burn
+    // compile time in the case that we're making progress.  We also have a hard
+    // iteration count limit in case there is crazy code.
+    unsigned Iteration = 0;
+    bool DevirtualizedCall = false;
+    do {
+      DEBUG(if (Iteration)
+              dbgs() << "  SCCPASSMGR: Re-visiting SCC, iteration #"
+                     << Iteration << '\n');
+      DevirtualizedCall = false;
+      Changed |= RunAllPassesOnSCC(CurSCC, CG, DevirtualizedCall);
+    } while (Iteration++ < MaxIterations && DevirtualizedCall);
+    
+    if (DevirtualizedCall)
+      DEBUG(dbgs() << "  CGSCCPASSMGR: Stopped iteration after " << Iteration
+                   << " times, due to -max-cg-scc-iterations\n");
+    
+    if (Iteration > MaxSCCIterations)
+      MaxSCCIterations = Iteration;
+    
+  }
+  Changed |= doFinalization(CG);
+  return Changed;
+}
+
+
+/// Initialize CG
+bool CGPassManager::doInitialization(CallGraph &CG) {
+  bool Changed = false;
+  for (unsigned i = 0, e = getNumContainedPasses(); i != e; ++i) {  
+    if (PMDataManager *PM = getContainedPass(i)->getAsPMDataManager()) {
+      assert(PM->getPassManagerType() == PMT_FunctionPassManager &&
+             "Invalid CGPassManager member");
+      Changed |= ((FPPassManager*)PM)->doInitialization(CG.getModule());
+    } else {
+      Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doInitialization(CG);
+    }
+  }
+  return Changed;
+}
+
+/// Finalize CG
+bool CGPassManager::doFinalization(CallGraph &CG) {
+  bool Changed = false;
+  for (unsigned i = 0, e = getNumContainedPasses(); i != e; ++i) {  
+    if (PMDataManager *PM = getContainedPass(i)->getAsPMDataManager()) {
+      assert(PM->getPassManagerType() == PMT_FunctionPassManager &&
+             "Invalid CGPassManager member");
+      Changed |= ((FPPassManager*)PM)->doFinalization(CG.getModule());
+    } else {
+      Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doFinalization(CG);
+    }
+  }
+  return Changed;
+}
+
+//===----------------------------------------------------------------------===//
+// CallGraphSCC Implementation
+//===----------------------------------------------------------------------===//
+
+/// This informs the SCC and the pass manager that the specified
+/// Old node has been deleted, and New is to be used in its place.
+void CallGraphSCC::ReplaceNode(CallGraphNode *Old, CallGraphNode *New) {
+  assert(Old != New && "Should not replace node with self");
+  for (unsigned i = 0; ; ++i) {
+    assert(i != Nodes.size() && "Node not in SCC");
+    if (Nodes[i] != Old) continue;
+    Nodes[i] = New;
+    break;
+  }
+  
+  // Update the active scc_iterator so that it doesn't contain dangling
+  // pointers to the old CallGraphNode.
+  scc_iterator<CallGraph*> *CGI = (scc_iterator<CallGraph*>*)Context;
+  CGI->ReplaceNode(Old, New);
+}
+
+
+//===----------------------------------------------------------------------===//
+// CallGraphSCCPass Implementation
+//===----------------------------------------------------------------------===//
+
+/// Assign pass manager to manage this pass.
+void CallGraphSCCPass::assignPassManager(PMStack &PMS,
+                                         PassManagerType PreferredType) {
+  // Find CGPassManager 
+  while (!PMS.empty() &&
+         PMS.top()->getPassManagerType() > PMT_CallGraphPassManager)
+    PMS.pop();
+
+  assert(!PMS.empty() && "Unable to handle Call Graph Pass");
+  CGPassManager *CGP;
+  
+  if (PMS.top()->getPassManagerType() == PMT_CallGraphPassManager)
+    CGP = (CGPassManager*)PMS.top();
+  else {
+    // Create new Call Graph SCC Pass Manager if it does not exist. 
+    assert(!PMS.empty() && "Unable to create Call Graph Pass Manager");
+    PMDataManager *PMD = PMS.top();
+
+    // [1] Create new Call Graph Pass Manager
+    CGP = new CGPassManager();
+
+    // [2] Set up new manager's top level manager
+    PMTopLevelManager *TPM = PMD->getTopLevelManager();
+    TPM->addIndirectPassManager(CGP);
+
+    // [3] Assign manager to manage this new manager. This may create
+    // and push new managers into PMS
+    Pass *P = CGP;
+    TPM->schedulePass(P);
+
+    // [4] Push new manager into PMS
+    PMS.push(CGP);
+  }
+
+  CGP->add(this);
+}
+
+/// For this class, we declare that we require and preserve the call graph.
+/// If the derived class implements this method, it should
+/// always explicitly call the implementation here.
+void CallGraphSCCPass::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.addRequired<CallGraphWrapperPass>();
+  AU.addPreserved<CallGraphWrapperPass>();
+}
+
+
+//===----------------------------------------------------------------------===//
+// PrintCallGraphPass Implementation
+//===----------------------------------------------------------------------===//
+
+namespace {
+  /// PrintCallGraphPass - Print a Module corresponding to a call graph.
+  ///
+  class PrintCallGraphPass : public CallGraphSCCPass {
+    std::string Banner;
+    raw_ostream &Out;       // raw_ostream to print on.
+    
+  public:
+    static char ID;
+    PrintCallGraphPass(const std::string &B, raw_ostream &o)
+      : CallGraphSCCPass(ID), Banner(B), Out(o) {}
+
+    void getAnalysisUsage(AnalysisUsage &AU) const override {
+      AU.setPreservesAll();
+    }
+
+    bool runOnSCC(CallGraphSCC &SCC) override {
+      Out << Banner;
+      for (CallGraphNode *CGN : SCC) {
+        if (CGN->getFunction())
+          CGN->getFunction()->print(Out);
+        else
+          Out << "\nPrinting <null> Function\n";
+      }
+      return false;
+    }
+  };
+  
+} // end anonymous namespace.
+
+char PrintCallGraphPass::ID = 0;
+
+Pass *CallGraphSCCPass::createPrinterPass(raw_ostream &O,
+                                          const std::string &Banner) const {
+  return new PrintCallGraphPass(Banner, O);
+}
+

llvm/trunk/lib/Analysis/CallPrinter.cpp

+//===- CallPrinter.cpp - DOT printer for call graph -----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines '-dot-callgraph', which emit a callgraph.<fnname>.dot
+// containing the call graph of a module.
+//
+// There is also a pass available to directly call dotty ('-view-callgraph').
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/CallGraph.h"
+#include "llvm/Analysis/CallPrinter.h"
+#include "llvm/Analysis/DOTGraphTraitsPass.h"
+
+using namespace llvm;
+
+namespace llvm {
+
+template <> struct DOTGraphTraits<CallGraph *> : public DefaultDOTGraphTraits {
+  DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}
+
+  static std::string getGraphName(CallGraph *Graph) { return "Call graph"; }
+
+  std::string getNodeLabel(CallGraphNode *Node, CallGraph *Graph) {
+    if (Function *Func = Node->getFunction())
+      return Func->getName();
+
+    return "external node";
+  }
+};
+
+struct AnalysisCallGraphWrapperPassTraits {
+  static CallGraph *getGraph(CallGraphWrapperPass *P) {
+    return &P->getCallGraph();
+  }
+};
+
+} // end llvm namespace
+
+namespace {
+
+struct CallGraphViewer
+    : public DOTGraphTraitsModuleViewer<CallGraphWrapperPass, true, CallGraph *,
+                                        AnalysisCallGraphWrapperPassTraits> {
+  static char ID;
+
+  CallGraphViewer()
+      : DOTGraphTraitsModuleViewer<CallGraphWrapperPass, true, CallGraph *,
+                                   AnalysisCallGraphWrapperPassTraits>(
+            "callgraph", ID) {
+    initializeCallGraphViewerPass(*PassRegistry::getPassRegistry());
+  }
+};
+
+struct CallGraphPrinter : public DOTGraphTraitsModulePrinter<
+                              CallGraphWrapperPass, true, CallGraph *,
+                              AnalysisCallGraphWrapperPassTraits> {
+  static char ID;
+
+  CallGraphPrinter()
+      : DOTGraphTraitsModulePrinter<CallGraphWrapperPass, true, CallGraph *,
+                                    AnalysisCallGraphWrapperPassTraits>(
+            "callgraph", ID) {
+    initializeCallGraphPrinterPass(*PassRegistry::getPassRegistry());
+  }
+};
+
+} // end anonymous namespace
+
+char CallGraphViewer::ID = 0;
+INITIALIZE_PASS(CallGraphViewer, "view-callgraph", "View call graph", false,
+                false)
+
+char CallGraphPrinter::ID = 0;
+INITIALIZE_PASS(CallGraphPrinter, "dot-callgraph",
+                "Print call graph to 'dot' file", false, false)
+
+// Create methods available outside of this file, to use them
+// "include/llvm/LinkAllPasses.h". Otherwise the pass would be deleted by
+// the link time optimization.
+
+ModulePass *llvm::createCallGraphViewerPass() { return new CallGraphViewer(); }
+
+ModulePass *llvm::createCallGraphPrinterPass() {
+  return new CallGraphPrinter();
+}

llvm/trunk/lib/Analysis/GlobalsModRef.cpp

+//===- GlobalsModRef.cpp - Simple Mod/Ref Analysis for Globals ------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This simple pass provides alias and mod/ref information for global values
+// that do not have their address taken, and keeps track of whether functions
+// read or write memory (are "pure").  For this simple (but very common) case,
+// we can provide pretty accurate and useful information.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/GlobalsModRef.h"
+#include "llvm/ADT/SCCIterator.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/MemoryBuiltins.h"
+#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/InstIterator.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Pass.h"
+#include "llvm/Support/CommandLine.h"
+using namespace llvm;
+
+#define DEBUG_TYPE "globalsmodref-aa"
+
+STATISTIC(NumNonAddrTakenGlobalVars,
+          "Number of global vars without address taken");
+STATISTIC(NumNonAddrTakenFunctions,"Number of functions without address taken");
+STATISTIC(NumNoMemFunctions, "Number of functions that do not access memory");
+STATISTIC(NumReadMemFunctions, "Number of functions that only read memory");
+STATISTIC(NumIndirectGlobalVars, "Number of indirect global objects");
+
+// An option to enable unsafe alias results from the GlobalsModRef analysis.
+// When enabled, GlobalsModRef will provide no-alias results which in extremely
+// rare cases may not be conservatively correct. In particular, in the face of
+// transforms which cause assymetry between how effective GetUnderlyingObject
+// is for two pointers, it may produce incorrect results.
+//
+// These unsafe results have been returned by GMR for many years without
+// causing significant issues in the wild and so we provide a mechanism to
+// re-enable them for users of LLVM that have a particular performance
+// sensitivity and no known issues. The option also makes it easy to evaluate
+// the performance impact of these results.
+static cl::opt<bool> EnableUnsafeGlobalsModRefAliasResults(
+    "enable-unsafe-globalsmodref-alias-results", cl::init(false), cl::Hidden);
+
+/// The mod/ref information collected for a particular function.
+///
+/// We collect information about mod/ref behavior of a function here, both in
+/// general and as pertains to specific globals. We only have this detailed
+/// information when we know *something* useful about the behavior. If we
+/// saturate to fully general mod/ref, we remove the info for the function.
+class GlobalsModRef::FunctionInfo {
+  typedef SmallDenseMap<const GlobalValue *, ModRefInfo, 16> GlobalInfoMapType;
+
+  /// Build a wrapper struct that has 8-byte alignment. All heap allocations
+  /// should provide this much alignment at least, but this makes it clear we
+  /// specifically rely on this amount of alignment.
+  struct LLVM_ALIGNAS(8) AlignedMap {
+    AlignedMap() {}
+    AlignedMap(const AlignedMap &Arg) : Map(Arg.Map) {}
+    GlobalInfoMapType Map;
+  };
+
+  /// Pointer traits for our aligned map.
+  struct AlignedMapPointerTraits {
+    static inline void *getAsVoidPointer(AlignedMap *P) { return P; }
+    static inline AlignedMap *getFromVoidPointer(void *P) {
+      return (AlignedMap *)P;
+    }
+    enum { NumLowBitsAvailable = 3 };
+    static_assert(AlignOf<AlignedMap>::Alignment >= (1 << NumLowBitsAvailable),
+                  "AlignedMap insufficiently aligned to have enough low bits.");
+  };
+
+  /// The bit that flags that this function may read any global. This is
+  /// chosen to mix together with ModRefInfo bits.
+  enum { MayReadAnyGlobal = 4 };
+
+  /// Checks to document the invariants of the bit packing here.
+  static_assert((MayReadAnyGlobal & MRI_ModRef) == 0,
+                "ModRef and the MayReadAnyGlobal flag bits overlap.");
+  static_assert(((MayReadAnyGlobal | MRI_ModRef) >>
+                 AlignedMapPointerTraits::NumLowBitsAvailable) == 0,
+                "Insufficient low bits to store our flag and ModRef info.");
+
+public:
+  FunctionInfo() : Info() {}
+  ~FunctionInfo() {
+    delete Info.getPointer();
+  }
+  // Spell out the copy ond move constructors and assignment operators to get
+  // deep copy semantics and correct move semantics in the face of the
+  // pointer-int pair.
+  FunctionInfo(const FunctionInfo &Arg)
+      : Info(nullptr, Arg.Info.getInt()) {
+    if (const auto *ArgPtr = Arg.Info.getPointer())
+      Info.setPointer(new AlignedMap(*ArgPtr));
+  }
+  FunctionInfo(FunctionInfo &&Arg)
+      : Info(Arg.Info.getPointer(), Arg.Info.getInt()) {
+    Arg.Info.setPointerAndInt(nullptr, 0);
+  }
+  FunctionInfo &operator=(const FunctionInfo &RHS) {
+    delete Info.getPointer();
+    Info.setPointerAndInt(nullptr, RHS.Info.getInt());
+    if (const auto *RHSPtr = RHS.Info.getPointer())
+      Info.setPointer(new AlignedMap(*RHSPtr));
+    return *this;
+  }
+  FunctionInfo &operator=(FunctionInfo &&RHS) {
+    delete Info.getPointer();
+    Info.setPointerAndInt(RHS.Info.getPointer(), RHS.Info.getInt());
+    RHS.Info.setPointerAndInt(nullptr, 0);
+    return *this;
+  }
+
+  /// Returns the \c ModRefInfo info for this function.
+  ModRefInfo getModRefInfo() const {
+    return ModRefInfo(Info.getInt() & MRI_ModRef);
+  }
+
+  /// Adds new \c ModRefInfo for this function to its state.
+  void addModRefInfo(ModRefInfo NewMRI) {
+    Info.setInt(Info.getInt() | NewMRI);
+  }
+
+  /// Returns whether this function may read any global variable, and we don't
+  /// know which global.
+  bool mayReadAnyGlobal() const { return Info.getInt() & MayReadAnyGlobal; }
+
+  /// Sets this function as potentially reading from any global.
+  void setMayReadAnyGlobal() { Info.setInt(Info.getInt() | MayReadAnyGlobal); }
+
+  /// Returns the \c ModRefInfo info for this function w.r.t. a particular
+  /// global, which may be more precise than the general information above.
+  ModRefInfo getModRefInfoForGlobal(const GlobalValue &GV) const {
+    ModRefInfo GlobalMRI = mayReadAnyGlobal() ? MRI_Ref : MRI_NoModRef;
+    if (AlignedMap *P = Info.getPointer()) {
+      auto I = P->Map.find(&GV);
+      if (I != P->Map.end())
+        GlobalMRI = ModRefInfo(GlobalMRI | I->second);
+    }
+    return GlobalMRI;
+  }
+
+  /// Add mod/ref info from another function into ours, saturating towards
+  /// MRI_ModRef.
+  void addFunctionInfo(const FunctionInfo &FI) {
+    addModRefInfo(FI.getModRefInfo());
+
+    if (FI.mayReadAnyGlobal())
+      setMayReadAnyGlobal();
+
+    if (AlignedMap *P = FI.Info.getPointer())
+      for (const auto &G : P->Map)
+        addModRefInfoForGlobal(*G.first, G.second);
+  }
+
+  void addModRefInfoForGlobal(const GlobalValue &GV, ModRefInfo NewMRI) {
+    AlignedMap *P = Info.getPointer();
+    if (!P) {
+      P = new AlignedMap();
+      Info.setPointer(P);
+    }
+    auto &GlobalMRI = P->Map[&GV];
+    GlobalMRI = ModRefInfo(GlobalMRI | NewMRI);
+  }
+
+  /// Clear a global's ModRef info. Should be used when a global is being
+  /// deleted.
+  void eraseModRefInfoForGlobal(const GlobalValue &GV) {
+    if (AlignedMap *P = Info.getPointer())
+      P->Map.erase(&GV);
+  }
+
+private:
+  /// All of the information is encoded into a single pointer, with a three bit
+  /// integer in the low three bits. The high bit provides a flag for when this
+  /// function may read any global. The low two bits are the ModRefInfo. And
+  /// the pointer, when non-null, points to a map from GlobalValue to
+  /// ModRefInfo specific to that GlobalValue.
+  PointerIntPair<AlignedMap *, 3, unsigned, AlignedMapPointerTraits> Info;
+};
+
+void GlobalsModRef::DeletionCallbackHandle::deleted() {
+  Value *V = getValPtr();
+  if (auto *F = dyn_cast<Function>(V))
+    GMR.FunctionInfos.erase(F);
+
+  if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
+    if (GMR.NonAddressTakenGlobals.erase(GV)) {
+      // This global might be an indirect global.  If so, remove it and
+      // remove any AllocRelatedValues for it.
+      if (GMR.IndirectGlobals.erase(GV)) {
+        // Remove any entries in AllocsForIndirectGlobals for this global.
+        for (auto I = GMR.AllocsForIndirectGlobals.begin(),
+                  E = GMR.AllocsForIndirectGlobals.end();
+             I != E; ++I)
+          if (I->second == GV)
+            GMR.AllocsForIndirectGlobals.erase(I);
+      }
+
+      // Scan the function info we have collected and remove this global
+      // from all of them.
+      for (auto &FIPair : GMR.FunctionInfos)
+        FIPair.second.eraseModRefInfoForGlobal(*GV);
+    }
+  }
+
+  // If this is an allocation related to an indirect global, remove it.
+  GMR.AllocsForIndirectGlobals.erase(V);
+
+  // And clear out the handle.
+  setValPtr(nullptr);
+  GMR.Handles.erase(I);
+  // This object is now destroyed!
+}
+
+char GlobalsModRef::ID = 0;
+INITIALIZE_AG_PASS_BEGIN(GlobalsModRef, AliasAnalysis, "globalsmodref-aa",
+                         "Simple mod/ref analysis for globals", false, true,
+                         false)
+INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
+INITIALIZE_AG_PASS_END(GlobalsModRef, AliasAnalysis, "globalsmodref-aa",
+                       "Simple mod/ref analysis for globals", false, true,
+                       false)
+
+Pass *llvm::createGlobalsModRefPass() { return new GlobalsModRef(); }
+
+GlobalsModRef::GlobalsModRef() : ModulePass(ID) {
+  initializeGlobalsModRefPass(*PassRegistry::getPassRegistry());
+}
+
+FunctionModRefBehavior GlobalsModRef::getModRefBehavior(const Function *F) {
+  FunctionModRefBehavior Min = FMRB_UnknownModRefBehavior;
+
+  if (FunctionInfo *FI = getFunctionInfo(F)) {
+    if (FI->getModRefInfo() == MRI_NoModRef)
+      Min = FMRB_DoesNotAccessMemory;
+    else if ((FI->getModRefInfo() & MRI_Mod) == 0)
+      Min = FMRB_OnlyReadsMemory;
+  }
+
+  return FunctionModRefBehavior(AliasAnalysis::getModRefBehavior(F) & Min);
+}
+
+FunctionModRefBehavior GlobalsModRef::getModRefBehavior(ImmutableCallSite CS) {
+  FunctionModRefBehavior Min = FMRB_UnknownModRefBehavior;
+
+  if (const Function *F = CS.getCalledFunction())
+    if (FunctionInfo *FI = getFunctionInfo(F)) {
+      if (FI->getModRefInfo() == MRI_NoModRef)
+        Min = FMRB_DoesNotAccessMemory;
+      else if ((FI->getModRefInfo() & MRI_Mod) == 0)
+        Min = FMRB_OnlyReadsMemory;
+    }
+
+  return FunctionModRefBehavior(AliasAnalysis::getModRefBehavior(CS) & Min);
+}
+
+/// Returns the function info for the function, or null if we don't have
+/// anything useful to say about it.
+GlobalsModRef::FunctionInfo *GlobalsModRef::getFunctionInfo(const Function *F) {
+  auto I = FunctionInfos.find(F);
+  if (I != FunctionInfos.end())
+    return &I->second;
+  return nullptr;
+}
+
+/// AnalyzeGlobals - Scan through the users of all of the internal
+/// GlobalValue's in the program.  If none of them have their "address taken"
+/// (really, their address passed to something nontrivial), record this fact,
+/// and record the functions that they are used directly in.
+void GlobalsModRef::AnalyzeGlobals(Module &M) {
+  SmallPtrSet<Function *, 64> TrackedFunctions;
+  for (Function &F : M)
+    if (F.hasLocalLinkage())
+      if (!AnalyzeUsesOfPointer(&F)) {
+        // Remember that we are tracking this global.
+        NonAddressTakenGlobals.insert(&F);
+        TrackedFunctions.insert(&F);
+        Handles.emplace_front(*this, &F);
+        Handles.front().I = Handles.begin();
+        ++NumNonAddrTakenFunctions;
+      }
+
+  SmallPtrSet<Function *, 64> Readers, Writers;
+  for (GlobalVariable &GV : M.globals())
+    if (GV.hasLocalLinkage()) {
+      if (!AnalyzeUsesOfPointer(&GV, &Readers,
+                                GV.isConstant() ? nullptr : &Writers)) {
+        // Remember that we are tracking this global, and the mod/ref fns
+        NonAddressTakenGlobals.insert(&GV);
+        Handles.emplace_front(*this, &GV);
+        Handles.front().I = Handles.begin();
+
+        for (Function *Reader : Readers) {
+          if (TrackedFunctions.insert(Reader).second) {
+            Handles.emplace_front(*this, Reader);
+            Handles.front().I = Handles.begin();
+          }
+          FunctionInfos[Reader].addModRefInfoForGlobal(GV, MRI_Ref);
+        }
+
+        if (!GV.isConstant()) // No need to keep track of writers to constants
+          for (Function *Writer : Writers) {
+            if (TrackedFunctions.insert(Writer).second) {
+              Handles.emplace_front(*this, Writer);
+              Handles.front().I = Handles.begin();
+            }
+            FunctionInfos[Writer].addModRefInfoForGlobal(GV, MRI_Mod);
+          }
+        ++NumNonAddrTakenGlobalVars;
+
+        // If this global holds a pointer type, see if it is an indirect global.
+        if (GV.getType()->getElementType()->isPointerTy() &&
+            AnalyzeIndirectGlobalMemory(&GV))
+          ++NumIndirectGlobalVars;
+      }
+      Readers.clear();
+      Writers.clear();
+    }
+}
+
+/// AnalyzeUsesOfPointer - Look at all of the users of the specified pointer.
+/// If this is used by anything complex (i.e., the address escapes), return
+/// true.  Also, while we are at it, keep track of those functions that read and
+/// write to the value.
+///
+/// If OkayStoreDest is non-null, stores into this global are allowed.
+bool GlobalsModRef::AnalyzeUsesOfPointer(Value *V,
+                                         SmallPtrSetImpl<Function *> *Readers,
+                                         SmallPtrSetImpl<Function *> *Writers,
+                                         GlobalValue *OkayStoreDest) {
+  if (!V->getType()->isPointerTy())
+    return true;
+
+  for (Use &U : V->uses()) {
+    User *I = U.getUser();
+    if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
+      if (Readers)
+        Readers->insert(LI->getParent()->getParent());
+    } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
+      if (V == SI->getOperand(1)) {
+        if (Writers)
+          Writers->insert(SI->getParent()->getParent());
+      } else if (SI->getOperand(1) != OkayStoreDest) {
+        return true; // Storing the pointer
+      }
+    } else if (Operator::getOpcode(I) == Instruction::GetElementPtr) {
+      if (AnalyzeUsesOfPointer(I, Readers, Writers))
+        return true;
+    } else if (Operator::getOpcode(I) == Instruction::BitCast) {
+      if (AnalyzeUsesOfPointer(I, Readers, Writers, OkayStoreDest))
+        return true;
+    } else if (auto CS = CallSite(I)) {
+      // Make sure that this is just the function being called, not that it is
+      // passing into the function.
+      if (!CS.isCallee(&U)) {
+        // Detect calls to free.
+        if (isFreeCall(I, TLI)) {
+          if (Writers)
+            Writers->insert(CS->getParent()->getParent());
+        } else {
+          return true; // Argument of an unknown call.
+        }
+      }
+    } else if (ICmpInst *ICI = dyn_cast<ICmpInst>(I)) {
+      if (!isa<ConstantPointerNull>(ICI->getOperand(1)))
+        return true; // Allow comparison against null.
+    } else {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+/// AnalyzeIndirectGlobalMemory - We found an non-address-taken global variable
+/// which holds a pointer type.  See if the global always points to non-aliased
+/// heap memory: that is, all initializers of the globals are allocations, and
+/// those allocations have no use other than initialization of the global.
+/// Further, all loads out of GV must directly use the memory, not store the
+/// pointer somewhere.  If this is true, we consider the memory pointed to by
+/// GV to be owned by GV and can disambiguate other pointers from it.
+bool GlobalsModRef::AnalyzeIndirectGlobalMemory(GlobalValue *GV) {
+  // Keep track of values related to the allocation of the memory, f.e. the
+  // value produced by the malloc call and any casts.
+  std::vector<Value *> AllocRelatedValues;
+
+  // Walk the user list of the global.  If we find anything other than a direct
+  // load or store, bail out.
+  for (User *U : GV->users()) {
+    if (LoadInst *LI = dyn_cast<LoadInst>(U)) {
+      // The pointer loaded from the global can only be used in simple ways:
+      // we allow addressing of it and loading storing to it.  We do *not* allow
+      // storing the loaded pointer somewhere else or passing to a function.
+      if (AnalyzeUsesOfPointer(LI))
+        return false; // Loaded pointer escapes.
+      // TODO: Could try some IP mod/ref of the loaded pointer.
+    } else if (StoreInst *SI = dyn_cast<StoreInst>(U)) {
+      // Storing the global itself.
+      if (SI->getOperand(0) == GV)
+        return false;
+
+      // If storing the null pointer, ignore it.
+      if (isa<ConstantPointerNull>(SI->getOperand(0)))
+        continue;
+
+      // Check the value being stored.
+      Value *Ptr = GetUnderlyingObject(SI->getOperand(0),
+                                       GV->getParent()->getDataLayout());
+
+      if (!isAllocLikeFn(Ptr, TLI))
+        return false; // Too hard to analyze.
+
+      // Analyze all uses of the allocation.  If any of them are used in a
+      // non-simple way (e.g. stored to another global) bail out.
+      if (AnalyzeUsesOfPointer(Ptr, /*Readers*/ nullptr, /*Writers*/ nullptr,
+                               GV))
+        return false; // Loaded pointer escapes.
+
+      // Remember that this allocation is related to the indirect global.
+      AllocRelatedValues.push_back(Ptr);
+    } else {
+      // Something complex, bail out.
+      return false;
+    }
+  }
+
+  // Okay, this is an indirect global.  Remember all of the allocations for
+  // this global in AllocsForIndirectGlobals.
+  while (!AllocRelatedValues.empty()) {
+    AllocsForIndirectGlobals[AllocRelatedValues.back()] = GV;
+    Handles.emplace_front(*this, AllocRelatedValues.back());
+    Handles.front().I = Handles.begin();
+    AllocRelatedValues.pop_back();
+  }
+  IndirectGlobals.insert(GV);
+  Handles.emplace_front(*this, GV);
+  Handles.front().I = Handles.begin();
+  return true;
+}
+
+/// AnalyzeCallGraph - At this point, we know the functions where globals are
+/// immediately stored to and read from.  Propagate this information up the call
+/// graph to all callers and compute the mod/ref info for all memory for each
+/// function.
+void GlobalsModRef::AnalyzeCallGraph(CallGraph &CG, Module &M) {
+  // We do a bottom-up SCC traversal of the call graph.  In other words, we
+  // visit all callees before callers (leaf-first).
+  for (scc_iterator<CallGraph *> I = scc_begin(&CG); !I.isAtEnd(); ++I) {
+    const std::vector<CallGraphNode *> &SCC = *I;
+    assert(!SCC.empty() && "SCC with no functions?");
+
+    if (!SCC[0]->getFunction()) {
+      // Calls externally - can't say anything useful.  Remove any existing
+      // function records (may have been created when scanning globals).
+      for (auto *Node : SCC)
+        FunctionInfos.erase(Node->getFunction());
+      continue;
+    }
+
+    FunctionInfo &FI = FunctionInfos[SCC[0]->getFunction()];
+    bool KnowNothing = false;
+
+    // Collect the mod/ref properties due to called functions.  We only compute
+    // one mod-ref set.
+    for (unsigned i = 0, e = SCC.size(); i != e && !KnowNothing; ++i) {
+      Function *F = SCC[i]->getFunction();
+      if (!F) {
+        KnowNothing = true;
+        break;
+      }
+
+      if (F->isDeclaration()) {
+        // Try to get mod/ref behaviour from function attributes.
+        if (F->doesNotAccessMemory()) {
+          // Can't do better than that!
+        } else if (F->onlyReadsMemory()) {
+          FI.addModRefInfo(MRI_Ref);
+          if (!F->isIntrinsic())
+            // This function might call back into the module and read a global -
+            // consider every global as possibly being read by this function.
+            FI.setMayReadAnyGlobal();
+        } else {
+          FI.addModRefInfo(MRI_ModRef);
+          // Can't say anything useful unless it's an intrinsic - they don't
+          // read or write global variables of the kind considered here.
+          KnowNothing = !F->isIntrinsic();
+        }
+        continue;
+      }
+
+      for (CallGraphNode::iterator CI = SCC[i]->begin(), E = SCC[i]->end();
+           CI != E && !KnowNothing; ++CI)
+        if (Function *Callee = CI->second->getFunction()) {
+          if (FunctionInfo *CalleeFI = getFunctionInfo(Callee)) {
+            // Propagate function effect up.
+            FI.addFunctionInfo(*CalleeFI);
+          } else {
+            // Can't say anything about it.  However, if it is inside our SCC,
+            // then nothing needs to be done.
+            CallGraphNode *CalleeNode = CG[Callee];
+            if (std::find(SCC.begin(), SCC.end(), CalleeNode) == SCC.end())
+              KnowNothing = true;
+          }
+        } else {
+          KnowNothing = true;
+        }
+    }
+
+    // If we can't say anything useful about this SCC, remove all SCC functions
+    // from the FunctionInfos map.
+    if (KnowNothing) {
+      for (auto *Node : SCC)
+        FunctionInfos.erase(Node->getFunction());
+      continue;
+    }
+
+    // Scan the function bodies for explicit loads or stores.
+    for (auto *Node : SCC) {
+      if (FI.getModRefInfo() == MRI_ModRef)
+        break; // The mod/ref lattice saturates here.
+      for (Instruction &I : instructions(Node->getFunction())) {
+        if (FI.getModRefInfo() == MRI_ModRef)
+          break; // The mod/ref lattice saturates here.
+
+        // We handle calls specially because the graph-relevant aspects are
+        // handled above.
+        if (auto CS = CallSite(&I)) {
+          if (isAllocationFn(&I, TLI) || isFreeCall(&I, TLI)) {
+            // FIXME: It is completely unclear why this is necessary and not
+            // handled by the above graph code.
+            FI.addModRefInfo(MRI_ModRef);
+          } else if (Function *Callee = CS.getCalledFunction()) {
+            // The callgraph doesn't include intrinsic calls.
+            if (Callee->isIntrinsic()) {
+              FunctionModRefBehavior Behaviour =
+                  AliasAnalysis::getModRefBehavior(Callee);
+              FI.addModRefInfo(ModRefInfo(Behaviour & MRI_ModRef));
+            }
+          }
+          continue;
+        }
+
+        // All non-call instructions we use the primary predicates for whether
+        // thay read or write memory.
+        if (I.mayReadFromMemory())
+          FI.addModRefInfo(MRI_Ref);
+        if (I.mayWriteToMemory())
+          FI.addModRefInfo(MRI_Mod);
+      }
+    }
+
+    if ((FI.getModRefInfo() & MRI_Mod) == 0)
+      ++NumReadMemFunctions;
+    if (FI.getModRefInfo() == MRI_NoModRef)
+      ++NumNoMemFunctions;
+
+    // Finally, now that we know the full effect on this SCC, clone the
+    // information to each function in the SCC.
+    for (unsigned i = 1, e = SCC.size(); i != e; ++i)
+      FunctionInfos[SCC[i]->getFunction()] = FI;
+  }
+}
+
+// There are particular cases where we can conclude no-alias between
+// a non-addr-taken global and some other underlying object. Specifically,
+// a non-addr-taken global is known to not be escaped from any function. It is
+// also incorrect for a transformation to introduce an escape of a global in
+// a way that is observable when it was not there previously. One function
+// being transformed to introduce an escape which could possibly be observed
+// (via loading from a global or the return value for example) within another
+// function is never safe. If the observation is made through non-atomic
+// operations on different threads, it is a data-race and UB. If the
+// observation is well defined, by being observed the transformation would have
+// changed program behavior by introducing the observed escape, making it an
+// invalid transform.
+//
+// This property does require that transformations which *temporarily* escape
+// a global that was not previously escaped, prior to restoring it, cannot rely
+// on the results of GMR::alias. This seems a reasonable restriction, although
+// currently there is no way to enforce it. There is also no realistic
+// optimization pass that would make this mistake. The closest example is
+// a transformation pass which does reg2mem of SSA values but stores them into
+// global variables temporarily before restoring the global variable's value.
+// This could be useful to expose "benign" races for example. However, it seems
+// reasonable to require that a pass which introduces escapes of global
+// variables in this way to either not trust AA results while the escape is
+// active, or to be forced to operate as a module pass that cannot co-exist
+// with an alias analysis such as GMR.
+bool GlobalsModRef::isNonEscapingGlobalNoAlias(const GlobalValue *GV,
+                                               const Value *V) {
+  // In order to know that the underlying object cannot alias the
+  // non-addr-taken global, we must know that it would have to be an escape.
+  // Thus if the underlying object is a function argument, a load from
+  // a global, or the return of a function, it cannot alias. We can also
+  // recurse through PHI nodes and select nodes provided all of their inputs
+  // resolve to one of these known-escaping roots.
+  SmallPtrSet<const Value *, 8> Visited;
+  SmallVector<const Value *, 8> Inputs;
+  Visited.insert(V);
+  Inputs.push_back(V);
+  int Depth = 0;
+  do {
+    const Value *Input = Inputs.pop_back_val();
+
+    if (auto *InputGV = dyn_cast<GlobalValue>(Input)) {
+      // If one input is the very global we're querying against, then we can't
+      // conclude no-alias.
+      if (InputGV == GV)
+        return false;
+
+      // Distinct GlobalVariables never alias, unless overriden or zero-sized.
+      // FIXME: The condition can be refined, but be conservative for now.
+      auto *GVar = dyn_cast<GlobalVariable>(GV);
+      auto *InputGVar = dyn_cast<GlobalVariable>(InputGV);
+      if (GVar && InputGVar &&
+          !GVar->isDeclaration() && !InputGVar->isDeclaration() &&
+          !GVar->mayBeOverridden() && !InputGVar->mayBeOverridden()) {
+        Type *GVType = GVar->getInitializer()->getType();
+        Type *InputGVType = InputGVar->getInitializer()->getType();
+        if (GVType->isSized() && InputGVType->isSized() &&
+            (DL->getTypeAllocSize(GVType) > 0) &&
+            (DL->getTypeAllocSize(InputGVType) > 0))
+          continue;
+      }
+
+      // Conservatively return false, even though we could be smarter
+      // (e.g. look through GlobalAliases).
+      return false;
+    }
+
+    if (isa<Argument>(Input) || isa<CallInst>(Input) ||
+        isa<InvokeInst>(Input)) {
+      // Arguments to functions or returns from functions are inherently
+      // escaping, so we can immediately classify those as not aliasing any
+      // non-addr-taken globals.
+      continue;
+    }
+    if (auto *LI = dyn_cast<LoadInst>(Input)) {
+      // A pointer loaded from a global would have been captured, and we know
+      // that the global is non-escaping, so no alias.
+      if (isa<GlobalValue>(GetUnderlyingObject(LI->getPointerOperand(), *DL)))
+        continue;
+
+      // Otherwise, a load could come from anywhere, so bail.
+      return false;
+    }
+
+    // Recurse through a limited number of selects and PHIs. This is an
+    // arbitrary depth of 4, lower numbers could be used to fix compile time
+    // issues if needed, but this is generally expected to be only be important
+    // for small depths.
+    if (++Depth > 4)
+      return false;
+    if (auto *SI = dyn_cast<SelectInst>(Input)) {
+      const Value *LHS = GetUnderlyingObject(SI->getTrueValue(), *DL);
+      const Value *RHS = GetUnderlyingObject(SI->getFalseValue(), *DL);
+      if (Visited.insert(LHS).second)
+        Inputs.push_back(LHS);
+      if (Visited.insert(RHS).second)
+        Inputs.push_back(RHS);
+      continue;
+    }
+    if (auto *PN = dyn_cast<PHINode>(Input)) {
+      for (const Value *Op : PN->incoming_values()) {
+        Op = GetUnderlyingObject(Op, *DL);
+        if (Visited.insert(Op).second)
+          Inputs.push_back(Op);
+      }
+      continue;
+    }
+
+    // FIXME: It would be good to handle other obvious no-alias cases here, but
+    // it isn't clear how to do so reasonbly without building a small version
+    // of BasicAA into this code. We could recurse into AliasAnalysis::alias
+    // here but that seems likely to go poorly as we're inside the
+    // implementation of such a query. Until then, just conservatievly retun
+    // false.
+    return false;
+  } while (!Inputs.empty());
+
+  // If all the inputs to V were definitively no-alias, then V is no-alias.
+  return true;
+}
+
+/// alias - If one of the pointers is to a global that we are tracking, and the
+/// other is some random pointer, we know there cannot be an alias, because the
+/// address of the global isn't taken.
+AliasResult GlobalsModRef::alias(const MemoryLocation &LocA,
+                                 const MemoryLocation &LocB) {
+  // Get the base object these pointers point to.
+  const Value *UV1 = GetUnderlyingObject(LocA.Ptr, *DL);
+  const Value *UV2 = GetUnderlyingObject(LocB.Ptr, *DL);
+
+  // If either of the underlying values is a global, they may be non-addr-taken
+  // globals, which we can answer queries about.
+  const GlobalValue *GV1 = dyn_cast<GlobalValue>(UV1);
+  const GlobalValue *GV2 = dyn_cast<GlobalValue>(UV2);
+  if (GV1 || GV2) {
+    // If the global's address is taken, pretend we don't know it's a pointer to
+    // the global.
+    if (GV1 && !NonAddressTakenGlobals.count(GV1))
+      GV1 = nullptr;
+    if (GV2 && !NonAddressTakenGlobals.count(GV2))
+      GV2 = nullptr;
+
+    // If the two pointers are derived from two different non-addr-taken
+    // globals we know these can't alias.
+    if (GV1 && GV2 && GV1 != GV2)
+      return NoAlias;
+
+    // If one is and the other isn't, it isn't strictly safe but we can fake
+    // this result if necessary for performance. This does not appear to be
+    // a common problem in practice.
+    if (EnableUnsafeGlobalsModRefAliasResults)
+      if ((GV1 || GV2) && GV1 != GV2)
+        return NoAlias;
+
+    // Check for a special case where a non-escaping global can be used to
+    // conclude no-alias.
+    if ((GV1 || GV2) && GV1 != GV2) {
+      const GlobalValue *GV = GV1 ? GV1 : GV2;
+      const Value *UV = GV1 ? UV2 : UV1;
+      if (isNonEscapingGlobalNoAlias(GV, UV))
+        return NoAlias;
+    }
+
+    // Otherwise if they are both derived from the same addr-taken global, we
+    // can't know the two accesses don't overlap.
+  }
+
+  // These pointers may be based on the memory owned by an indirect global.  If
+  // so, we may be able to handle this.  First check to see if the base pointer
+  // is a direct load from an indirect global.
+  GV1 = GV2 = nullptr;
+  if (const LoadInst *LI = dyn_cast<LoadInst>(UV1))
+    if (GlobalVariable *GV = dyn_cast<GlobalVariable>(LI->getOperand(0)))
+      if (IndirectGlobals.count(GV))
+        GV1 = GV;
+  if (const LoadInst *LI = dyn_cast<LoadInst>(UV2))
+    if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(LI->getOperand(0)))
+      if (IndirectGlobals.count(GV))
+        GV2 = GV;
+
+  // These pointers may also be from an allocation for the indirect global.  If
+  // so, also handle them.
+  if (!GV1)
+    GV1 = AllocsForIndirectGlobals.lookup(UV1);
+  if (!GV2)
+    GV2 = AllocsForIndirectGlobals.lookup(UV2);
+
+  // Now that we know whether the two pointers are related to indirect globals,
+  // use this to disambiguate the pointers. If the pointers are based on
+  // different indirect globals they cannot alias.
+  if (GV1 && GV2 && GV1 != GV2)
+    return NoAlias;
+
+  // If one is based on an indirect global and the other isn't, it isn't
+  // strictly safe but we can fake this result if necessary for performance.
+  // This does not appear to be a common problem in practice.
+  if (EnableUnsafeGlobalsModRefAliasResults)
+    if ((GV1 || GV2) && GV1 != GV2)
+      return NoAlias;
+
+  return AliasAnalysis::alias(LocA, LocB);
+}
+
+ModRefInfo GlobalsModRef::getModRefInfo(ImmutableCallSite CS,
+                                        const MemoryLocation &Loc) {
+  unsigned Known = MRI_ModRef;
+
+  // If we are asking for mod/ref info of a direct call with a pointer to a
+  // global we are tracking, return information if we have it.
+  const DataLayout &DL = CS.getCaller()->getParent()->getDataLayout();
+  if (const GlobalValue *GV =
+          dyn_cast<GlobalValue>(GetUnderlyingObject(Loc.Ptr, DL)))
+    if (GV->hasLocalLinkage())
+      if (const Function *F = CS.getCalledFunction())
+        if (NonAddressTakenGlobals.count(GV))
+          if (const FunctionInfo *FI = getFunctionInfo(F))
+            Known = FI->getModRefInfoForGlobal(*GV);
+
+  if (Known == MRI_NoModRef)
+    return MRI_NoModRef; // No need to query other mod/ref analyses
+  return ModRefInfo(Known & AliasAnalysis::getModRefInfo(CS, Loc));
+}

llvm/trunk/lib/Analysis/IPA/CMakeLists.txt

-add_llvm_library(LLVMipa
-  CallGraph.cpp
-  CallGraphSCCPass.cpp
-  CallPrinter.cpp
-  GlobalsModRef.cpp
-  IPA.cpp
-  InlineCost.cpp
-  )
-
-add_dependencies(LLVMipa intrinsics_gen)

llvm/trunk/lib/Analysis/IPA/CallGraph.cpp

-//===- CallGraph.cpp - Build a Module's call graph ------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Analysis/CallGraph.h"
-#include "llvm/IR/CallSite.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/IntrinsicInst.h"
-#include "llvm/IR/Module.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/raw_ostream.h"
-using namespace llvm;
-
-//===----------------------------------------------------------------------===//
-// Implementations of the CallGraph class methods.
-//
-
-CallGraph::CallGraph(Module &M)
-    : M(M), Root(nullptr), ExternalCallingNode(getOrInsertFunction(nullptr)),
-      CallsExternalNode(llvm::make_unique<CallGraphNode>(nullptr)) {
-  // Add every function to the call graph.
-  for (Function &F : M)
-    addToCallGraph(&F);
-
-  // If we didn't find a main function, use the external call graph node
-  if (!Root)
-    Root = ExternalCallingNode;
-}
-
-CallGraph::CallGraph(CallGraph &&Arg)
-    : M(Arg.M), FunctionMap(std::move(Arg.FunctionMap)), Root(Arg.Root),
-      ExternalCallingNode(Arg.ExternalCallingNode),
-      CallsExternalNode(std::move(Arg.CallsExternalNode)) {
-  Arg.FunctionMap.clear();
-  Arg.Root = nullptr;
-  Arg.ExternalCallingNode = nullptr;
-}
-
-CallGraph::~CallGraph() {
-  // CallsExternalNode is not in the function map, delete it explicitly.
-  if (CallsExternalNode)
-    CallsExternalNode->allReferencesDropped();
-
-// Reset all node's use counts to zero before deleting them to prevent an
-// assertion from firing.
-#ifndef NDEBUG
-  for (auto &I : FunctionMap)
-    I.second->allReferencesDropped();
-#endif
-}
-
-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));
-      }
-    }
-}
-
-void CallGraph::print(raw_ostream &OS) const {
-  OS << "CallGraph Root is: ";
-  if (Function *F = Root->getFunction())
-    OS << F->getName() << "\n";
-  else {
-    OS << "<<null function: 0x" << Root << ">>\n";
-  }
-
-  // Print in a deterministic order by sorting CallGraphNodes by name.  We do
-  // this here to avoid slowing down the non-printing fast path.
-
-  SmallVector<CallGraphNode *, 16> Nodes;
-  Nodes.reserve(FunctionMap.size());
-
-  for (auto I = begin(), E = end(); I != E; ++I)
-    Nodes.push_back(I->second.get());
-
-  std::sort(Nodes.begin(), Nodes.end(),
-            [](CallGraphNode *LHS, CallGraphNode *RHS) {
-    if (Function *LF = LHS->getFunction())
-      if (Function *RF = RHS->getFunction())
-        return LF->getName() < RF->getName();
-
-    return RHS->getFunction() != nullptr;
-  });
-
-  for (CallGraphNode *CN : Nodes)
-    CN->print(OS);
-}
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-void CallGraph::dump() const { print(dbgs()); }
-#endif
-
-// removeFunctionFromModule - Unlink the function from this module, returning
-// it.  Because this removes the function from the module, the call graph node
-// is destroyed.  This is only valid if the function does not call any other
-// functions (ie, there are no edges in it's CGN).  The easiest way to do this
-// is to dropAllReferences before calling this.
-//
-Function *CallGraph::removeFunctionFromModule(CallGraphNode *CGN) {
-  assert(CGN->empty() && "Cannot remove function from call "
-         "graph if it references other functions!");
-  Function *F = CGN->getFunction(); // Get the function for the call graph node
-  FunctionMap.erase(F);             // Remove the call graph node from the map
-
-  M.getFunctionList().remove(F);
-  return F;
-}
-
-/// spliceFunction - Replace the function represented by this node by another.
-/// This does not rescan the body of the function, so it is suitable when
-/// splicing the body of the old function to the new while also updating all
-/// callers from old to new.
-///
-void CallGraph::spliceFunction(const Function *From, const Function *To) {
-  assert(FunctionMap.count(From) && "No CallGraphNode for function!");
-  assert(!FunctionMap.count(To) &&
-         "Pointing CallGraphNode at a function that already exists");
-  FunctionMapTy::iterator I = FunctionMap.find(From);
-  I->second->F = const_cast<Function*>(To);
-  FunctionMap[To] = std::move(I->second);
-  FunctionMap.erase(I);
-}
-
-// getOrInsertFunction - This method is identical to calling operator[], but
-// it will insert a new CallGraphNode for the specified function if one does
-// not already exist.
-CallGraphNode *CallGraph::getOrInsertFunction(const Function *F) {
-  auto &CGN = FunctionMap[F];
-  if (CGN)
-    return CGN.get();
-
-  assert((!F || F->getParent() == &M) && "Function not in current module!");
-  CGN = llvm::make_unique<CallGraphNode>(const_cast<Function *>(F));
-  return CGN.get();
-}
-
-//===----------------------------------------------------------------------===//
-// Implementations of the CallGraphNode class methods.
-//
-
-void CallGraphNode::print(raw_ostream &OS) const {
-  if (Function *F = getFunction())
-    OS << "Call graph node for function: '" << F->getName() << "'";
-  else
-    OS << "Call graph node <<null function>>";
-  
-  OS << "<<" << this << ">>  #uses=" << getNumReferences() << '\n';
-
-  for (const_iterator I = begin(), E = end(); I != E; ++I) {
-    OS << "  CS<" << I->first << "> calls ";
-    if (Function *FI = I->second->getFunction())
-      OS << "function '" << FI->getName() <<"'\n";
-    else
-      OS << "external node\n";
-  }
-  OS << '\n';
-}
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-void CallGraphNode::dump() const { print(dbgs()); }
-#endif
-
-/// removeCallEdgeFor - This method removes the edge in the node for the
-/// specified call site.  Note that this method takes linear time, so it
-/// should be used sparingly.
-void CallGraphNode::removeCallEdgeFor(CallSite CS) {
-  for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
-    assert(I != CalledFunctions.end() && "Cannot find callsite to remove!");
-    if (I->first == CS.getInstruction()) {
-      I->second->DropRef();
-      *I = CalledFunctions.back();
-      CalledFunctions.pop_back();
-      return;
-    }
-  }
-}
-
-// removeAnyCallEdgeTo - This method removes any call edges from this node to
-// the specified callee function.  This takes more time to execute than
-// removeCallEdgeTo, so it should not be used unless necessary.
-void CallGraphNode::removeAnyCallEdgeTo(CallGraphNode *Callee) {
-  for (unsigned i = 0, e = CalledFunctions.size(); i != e; ++i)
-    if (CalledFunctions[i].second == Callee) {
-      Callee->DropRef();
-      CalledFunctions[i] = CalledFunctions.back();
-      CalledFunctions.pop_back();
-      --i; --e;
-    }
-}
-
-/// removeOneAbstractEdgeTo - Remove one edge associated with a null callsite
-/// from this node to the specified callee function.
-void CallGraphNode::removeOneAbstractEdgeTo(CallGraphNode *Callee) {
-  for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
-    assert(I != CalledFunctions.end() && "Cannot find callee to remove!");
-    CallRecord &CR = *I;
-    if (CR.second == Callee && CR.first == nullptr) {
-      Callee->DropRef();
-      *I = CalledFunctions.back();
-      CalledFunctions.pop_back();
-      return;
-    }
-  }
-}
-
-/// replaceCallEdge - This method replaces the edge in the node for the
-/// specified call site with a new one.  Note that this method takes linear
-/// time, so it should be used sparingly.
-void CallGraphNode::replaceCallEdge(CallSite CS,
-                                    CallSite NewCS, CallGraphNode *NewNode){
-  for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
-    assert(I != CalledFunctions.end() && "Cannot find callsite to remove!");
-    if (I->first == CS.getInstruction()) {
-      I->second->DropRef();
-      I->first = NewCS.getInstruction();
-      I->second = NewNode;
-      NewNode->AddRef();
-      return;
-    }
-  }
-}
-
-//===----------------------------------------------------------------------===//
-// Out-of-line definitions of CallGraphAnalysis class members.
-//
-
-char CallGraphAnalysis::PassID;
-
-//===----------------------------------------------------------------------===//
-// Implementations of the CallGraphWrapperPass class methods.
-//
-
-CallGraphWrapperPass::CallGraphWrapperPass() : ModulePass(ID) {
-  initializeCallGraphWrapperPassPass(*PassRegistry::getPassRegistry());
-}
-
-CallGraphWrapperPass::~CallGraphWrapperPass() {}
-
-void CallGraphWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
-  AU.setPreservesAll();
-}
-
-bool CallGraphWrapperPass::runOnModule(Module &M) {
-  // All the real work is done in the constructor for the CallGraph.
-  G.reset(new CallGraph(M));
-  return false;
-}
-
-INITIALIZE_PASS(CallGraphWrapperPass, "basiccg", "CallGraph Construction",
-                false, true)
-
-char CallGraphWrapperPass::ID = 0;
-
-void CallGraphWrapperPass::releaseMemory() { G.reset(); }
-
-void CallGraphWrapperPass::print(raw_ostream &OS, const Module *) const {
-  if (!G) {
-    OS << "No call graph has been built!\n";
-    return;
-  }
-
-  // Just delegate.
-  G->print(OS);
-}
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-void CallGraphWrapperPass::dump() const { print(dbgs(), nullptr); }
-#endif

llvm/trunk/lib/Analysis/IPA/CallGraphSCCPass.cpp

-//===- CallGraphSCCPass.cpp - Pass that operates BU on call graph ---------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the CallGraphSCCPass class, which is used for passes
-// which are implemented as bottom-up traversals on the call graph.  Because
-// there may be cycles in the call graph, passes of this type operate on the
-// call-graph in SCC order: that is, they process function bottom-up, except for
-// recursive functions, which they process all at once.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Analysis/CallGraphSCCPass.h"
-#include "llvm/ADT/SCCIterator.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Analysis/CallGraph.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/IntrinsicInst.h"
-#include "llvm/IR/LLVMContext.h"
-#include "llvm/IR/LegacyPassManagers.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/Timer.h"
-#include "llvm/Support/raw_ostream.h"
-using namespace llvm;
-
-#define DEBUG_TYPE "cgscc-passmgr"
-
-static cl::opt<unsigned> 
-MaxIterations("max-cg-scc-iterations", cl::ReallyHidden, cl::init(4));
-
-STATISTIC(MaxSCCIterations, "Maximum CGSCCPassMgr iterations on one SCC");
-
-//===----------------------------------------------------------------------===//
-// CGPassManager
-//
-/// CGPassManager manages FPPassManagers and CallGraphSCCPasses.
-
-namespace {
-
-class CGPassManager : public ModulePass, public PMDataManager {
-public:
-  static char ID;
-  explicit CGPassManager() 
-    : ModulePass(ID), PMDataManager() { }
-
-  /// 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) override;
-
-  using ModulePass::doInitialization;
-  using ModulePass::doFinalization;
-
-  bool doInitialization(CallGraph &CG);
-  bool doFinalization(CallGraph &CG);
-
-  /// Pass Manager itself does not invalidate any analysis info.
-  void getAnalysisUsage(AnalysisUsage &Info) const override {
-    // CGPassManager walks SCC and it needs CallGraph.
-    Info.addRequired<CallGraphWrapperPass>();
-    Info.setPreservesAll();
-  }
-
-  const char *getPassName() const override {
-    return "CallGraph Pass Manager";
-  }
-
-  PMDataManager *getAsPMDataManager() override { return this; }
-  Pass *getAsPass() override { return this; }
-
-  // Print passes managed by this manager
-  void dumpPassStructure(unsigned Offset) override {
-    errs().indent(Offset*2) << "Call Graph SCC Pass Manager\n";
-    for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
-      Pass *P = getContainedPass(Index);
-      P->dumpPassStructure(Offset + 1);
-      dumpLastUses(P, Offset+1);
-    }
-  }
-
-  Pass *getContainedPass(unsigned N) {
-    assert(N < PassVector.size() && "Pass number out of range!");
-    return static_cast<Pass *>(PassVector[N]);
-  }
-
-  PassManagerType getPassManagerType() const override {
-    return PMT_CallGraphPassManager; 
-  }
-  
-private:
-  bool RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG,
-                         bool &DevirtualizedCall);
-  
-  bool RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC,
-                    CallGraph &CG, bool &CallGraphUpToDate,
-                    bool &DevirtualizedCall);
-  bool RefreshCallGraph(CallGraphSCC &CurSCC, CallGraph &CG,
-                        bool IsCheckingMode);
-};
-
-} // end anonymous namespace.
-
-char CGPassManager::ID = 0;
-
-
-bool CGPassManager::RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC,
-                                 CallGraph &CG, bool &CallGraphUpToDate,
-                                 bool &DevirtualizedCall) {
-  bool Changed = false;
-  PMDataManager *PM = P->getAsPMDataManager();
-
-  if (!PM) {
-    CallGraphSCCPass *CGSP = (CallGraphSCCPass*)P;
-    if (!CallGraphUpToDate) {
-      DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false);
-      CallGraphUpToDate = true;
-    }
-
-    {
-      TimeRegion PassTimer(getPassTimer(CGSP));
-      Changed = CGSP->runOnSCC(CurSCC);
-    }
-    
-    // After the CGSCCPass is done, when assertions are enabled, use
-    // RefreshCallGraph to verify that the callgraph was correctly updated.
-#ifndef NDEBUG
-    if (Changed)
-      RefreshCallGraph(CurSCC, CG, true);
-#endif
-    
-    return Changed;
-  }
-  
-  
-  assert(PM->getPassManagerType() == PMT_FunctionPassManager &&
-         "Invalid CGPassManager member");
-  FPPassManager *FPP = (FPPassManager*)P;
-  
-  // Run pass P on all functions in the current SCC.
-  for (CallGraphNode *CGN : CurSCC) {
-    if (Function *F = CGN->getFunction()) {
-      dumpPassInfo(P, EXECUTION_MSG, ON_FUNCTION_MSG, F->getName());
-      {
-        TimeRegion PassTimer(getPassTimer(FPP));
-        Changed |= FPP->runOnFunction(*F);
-      }
-      F->getContext().yield();
-    }
-  }
-  
-  // The function pass(es) modified the IR, they may have clobbered the
-  // callgraph.
-  if (Changed && CallGraphUpToDate) {
-    DEBUG(dbgs() << "CGSCCPASSMGR: Pass Dirtied SCC: "
-                 << P->getPassName() << '\n');
-    CallGraphUpToDate = false;
-  }
-  return Changed;
-}
-
-
-/// Scan the functions in the specified CFG and resync the
-/// callgraph with the call sites found in it.  This is used after
-/// FunctionPasses have potentially munged the callgraph, and can be used after
-/// CallGraphSCC passes to verify that they correctly updated the callgraph.
-///
-/// This function returns true if it devirtualized an existing function call,
-/// meaning it turned an indirect call into a direct call.  This happens when
-/// a function pass like GVN optimizes away stuff feeding the indirect call.
-/// This never happens in checking mode.
-///
-bool CGPassManager::RefreshCallGraph(CallGraphSCC &CurSCC,
-                                     CallGraph &CG, bool CheckingMode) {
-  DenseMap<Value*, CallGraphNode*> CallSites;
-  
-  DEBUG(dbgs() << "CGSCCPASSMGR: Refreshing SCC with " << CurSCC.size()
-               << " nodes:\n";
-        for (CallGraphNode *CGN : CurSCC)
-          CGN->dump();
-        );
-
-  bool MadeChange = false;
-  bool DevirtualizedCall = false;
-  
-  // Scan all functions in the SCC.
-  unsigned FunctionNo = 0;
-  for (CallGraphSCC::iterator SCCIdx = CurSCC.begin(), E = CurSCC.end();
-       SCCIdx != E; ++SCCIdx, ++FunctionNo) {
-    CallGraphNode *CGN = *SCCIdx;
-    Function *F = CGN->getFunction();
-    if (!F || F->isDeclaration()) continue;
-    
-    // Walk the function body looking for call sites.  Sync up the call sites in
-    // CGN with those actually in the function.
-
-    // Keep track of the number of direct and indirect calls that were
-    // invalidated and removed.
-    unsigned NumDirectRemoved = 0, NumIndirectRemoved = 0;
-    
-    // Get the set of call sites currently in the function.
-    for (CallGraphNode::iterator I = CGN->begin(), E = CGN->end(); I != E; ) {
-      // If this call site is null, then the function pass deleted the call
-      // entirely and the WeakVH nulled it out.  
-      if (!I->first ||
-          // If we've already seen this call site, then the FunctionPass RAUW'd
-          // one call with another, which resulted in two "uses" in the edge
-          // list of the same call.
-          CallSites.count(I->first) ||
-
-          // If the call edge is not from a call or invoke, or it is a
-          // instrinsic call, then the function pass RAUW'd a call with 
-          // another value. This can happen when constant folding happens
-          // of well known functions etc.
-          !CallSite(I->first) ||
-          (CallSite(I->first).getCalledFunction() &&
-           CallSite(I->first).getCalledFunction()->isIntrinsic() &&
-           Intrinsic::isLeaf(
-               CallSite(I->first).getCalledFunction()->getIntrinsicID()))) {
-        assert(!CheckingMode &&
-               "CallGraphSCCPass did not update the CallGraph correctly!");
-        
-        // If this was an indirect call site, count it.
-        if (!I->second->getFunction())
-          ++NumIndirectRemoved;
-        else 
-          ++NumDirectRemoved;
-        
-        // Just remove the edge from the set of callees, keep track of whether
-        // I points to the last element of the vector.
-        bool WasLast = I + 1 == E;
-        CGN->removeCallEdge(I);
-        
-        // If I pointed to the last element of the vector, we have to bail out:
-        // iterator checking rejects comparisons of the resultant pointer with
-        // end.
-        if (WasLast)
-          break;
-        E = CGN->end();
-        continue;
-      }
-      
-      assert(!CallSites.count(I->first) &&
-             "Call site occurs in node multiple times");
-      
-      CallSite CS(I->first);
-      if (CS) {
-        Function *Callee = CS.getCalledFunction();
-        // Ignore intrinsics because they're not really function calls.
-        if (!Callee || !(Callee->isIntrinsic()))
-          CallSites.insert(std::make_pair(I->first, I->second));
-      }
-      ++I;
-    }
-    
-    // Loop over all of the instructions in the function, getting the callsites.
-    // Keep track of the number of direct/indirect calls added.
-    unsigned NumDirectAdded = 0, NumIndirectAdded = 0;
-    
-    for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
-      for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
-        CallSite CS(cast<Value>(I));
-        if (!CS) continue;
-        Function *Callee = CS.getCalledFunction();
-        if (Callee && Callee->isIntrinsic()) continue;
-        
-        // If this call site already existed in the callgraph, just verify it
-        // matches up to expectations and remove it from CallSites.
-        DenseMap<Value*, CallGraphNode*>::iterator ExistingIt =
-          CallSites.find(CS.getInstruction());
-        if (ExistingIt != CallSites.end()) {
-          CallGraphNode *ExistingNode = ExistingIt->second;
-
-          // Remove from CallSites since we have now seen it.
-          CallSites.erase(ExistingIt);
-          
-          // Verify that the callee is right.
-          if (ExistingNode->getFunction() == CS.getCalledFunction())
-            continue;
-          
-          // If we are in checking mode, we are not allowed to actually mutate
-          // the callgraph.  If this is a case where we can infer that the
-          // callgraph is less precise than it could be (e.g. an indirect call
-          // site could be turned direct), don't reject it in checking mode, and
-          // don't tweak it to be more precise.
-          if (CheckingMode && CS.getCalledFunction() &&
-              ExistingNode->getFunction() == nullptr)
-            continue;
-          
-          assert(!CheckingMode &&
-                 "CallGraphSCCPass did not update the CallGraph correctly!");
-          
-          // If not, we either went from a direct call to indirect, indirect to
-          // direct, or direct to different direct.
-          CallGraphNode *CalleeNode;
-          if (Function *Callee = CS.getCalledFunction()) {
-            CalleeNode = CG.getOrInsertFunction(Callee);
-            // Keep track of whether we turned an indirect call into a direct
-            // one.
-            if (!ExistingNode->getFunction()) {
-              DevirtualizedCall = true;
-              DEBUG(dbgs() << "  CGSCCPASSMGR: Devirtualized call to '"
-                           << Callee->getName() << "'\n");
-            }
-          } else {
-            CalleeNode = CG.getCallsExternalNode();
-          }
-
-          // Update the edge target in CGN.
-          CGN->replaceCallEdge(CS, CS, CalleeNode);
-          MadeChange = true;
-          continue;
-        }
-        
-        assert(!CheckingMode &&
-               "CallGraphSCCPass did not update the CallGraph correctly!");
-
-        // If the call site didn't exist in the CGN yet, add it.
-        CallGraphNode *CalleeNode;
-        if (Function *Callee = CS.getCalledFunction()) {
-          CalleeNode = CG.getOrInsertFunction(Callee);
-          ++NumDirectAdded;
-        } else {
-          CalleeNode = CG.getCallsExternalNode();
-          ++NumIndirectAdded;
-        }
-        
-        CGN->addCalledFunction(CS, CalleeNode);
-        MadeChange = true;
-      }
-    
-    // We scanned the old callgraph node, removing invalidated call sites and
-    // then added back newly found call sites.  One thing that can happen is
-    // that an old indirect call site was deleted and replaced with a new direct
-    // call.  In this case, we have devirtualized a call, and CGSCCPM would like
-    // to iteratively optimize the new code.  Unfortunately, we don't really
-    // have a great way to detect when this happens.  As an approximation, we
-    // just look at whether the number of indirect calls is reduced and the
-    // number of direct calls is increased.  There are tons of ways to fool this
-    // (e.g. DCE'ing an indirect call and duplicating an unrelated block with a
-    // direct call) but this is close enough.
-    if (NumIndirectRemoved > NumIndirectAdded &&
-        NumDirectRemoved < NumDirectAdded)
-      DevirtualizedCall = true;
-    
-    // After scanning this function, if we still have entries in callsites, then
-    // they are dangling pointers.  WeakVH should save us for this, so abort if
-    // this happens.
-    assert(CallSites.empty() && "Dangling pointers found in call sites map");
-    
-    // Periodically do an explicit clear to remove tombstones when processing
-    // large scc's.
-    if ((FunctionNo & 15) == 15)
-      CallSites.clear();
-  }
-
-  DEBUG(if (MadeChange) {
-          dbgs() << "CGSCCPASSMGR: Refreshed SCC is now:\n";
-          for (CallGraphNode *CGN : CurSCC)
-            CGN->dump();
-          if (DevirtualizedCall)
-            dbgs() << "CGSCCPASSMGR: Refresh devirtualized a call!\n";
-
-         } else {
-           dbgs() << "CGSCCPASSMGR: SCC Refresh didn't change call graph.\n";
-         }
-        );
-  (void)MadeChange;
-
-  return DevirtualizedCall;
-}
-
-/// Execute the body of the entire pass manager on the specified SCC.
-/// This keeps track of whether a function pass devirtualizes
-/// any calls and returns it in DevirtualizedCall.
-bool CGPassManager::RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG,
-                                      bool &DevirtualizedCall) {
-  bool Changed = false;
-  
-  // Keep track of whether the callgraph is known to be up-to-date or not.
-  // The CGSSC pass manager runs two types of passes:
-  // CallGraphSCC Passes and other random function passes.  Because other
-  // random function passes are not CallGraph aware, they may clobber the
-  // call graph by introducing new calls or deleting other ones.  This flag
-  // is set to false when we run a function pass so that we know to clean up
-  // the callgraph when we need to run a CGSCCPass again.
-  bool CallGraphUpToDate = true;
-
-  // Run all passes on current SCC.
-  for (unsigned PassNo = 0, e = getNumContainedPasses();
-       PassNo != e; ++PassNo) {
-    Pass *P = getContainedPass(PassNo);
-    
-    // If we're in -debug-pass=Executions mode, construct the SCC node list,
-    // otherwise avoid constructing this string as it is expensive.
-    if (isPassDebuggingExecutionsOrMore()) {
-      std::string Functions;
-  #ifndef NDEBUG
-      raw_string_ostream OS(Functions);
-      for (CallGraphSCC::iterator I = CurSCC.begin(), E = CurSCC.end();
-           I != E; ++I) {
-        if (I != CurSCC.begin()) OS << ", ";
-        (*I)->print(OS);
-      }
-      OS.flush();
-  #endif
-      dumpPassInfo(P, EXECUTION_MSG, ON_CG_MSG, Functions);
-    }
-    dumpRequiredSet(P);
-    
-    initializeAnalysisImpl(P);
-    
-    // Actually run this pass on the current SCC.
-    Changed |= RunPassOnSCC(P, CurSCC, CG,
-                            CallGraphUpToDate, DevirtualizedCall);
-    
-    if (Changed)
-      dumpPassInfo(P, MODIFICATION_MSG, ON_CG_MSG, "");
-    dumpPreservedSet(P);
-    
-    verifyPreservedAnalysis(P);      
-    removeNotPreservedAnalysis(P);
-    recordAvailableAnalysis(P);
-    removeDeadPasses(P, "", ON_CG_MSG);
-  }
-  
-  // If the callgraph was left out of date (because the last pass run was a
-  // functionpass), refresh it before we move on to the next SCC.
-  if (!CallGraphUpToDate)
-    DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false);
-  return Changed;
-}
-
-/// 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 CGPassManager::runOnModule(Module &M) {
-  CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
-  bool Changed = doInitialization(CG);
-  
-  // Walk the callgraph in bottom-up SCC order.
-  scc_iterator<CallGraph*> CGI = scc_begin(&CG);
-
-  CallGraphSCC CurSCC(&CGI);
-  while (!CGI.isAtEnd()) {
-    // Copy the current SCC and increment past it so that the pass can hack
-    // on the SCC if it wants to without invalidating our iterator.
-    const std::vector<CallGraphNode *> &NodeVec = *CGI;
-    CurSCC.initialize(NodeVec.data(), NodeVec.data() + NodeVec.size());
-    ++CGI;
-
-    // At the top level, we run all the passes in this pass manager on the
-    // functions in this SCC.  However, we support iterative compilation in the
-    // case where a function pass devirtualizes a call to a function.  For
-    // example, it is very common for a function pass (often GVN or instcombine)
-    // to eliminate the addressing that feeds into a call.  With that improved
-    // information, we would like the call to be an inline candidate, infer
-    // mod-ref information etc.
-    //
-    // Because of this, we allow iteration up to a specified iteration count.
-    // This only happens in the case of a devirtualized call, so we only burn
-    // compile time in the case that we're making progress.  We also have a hard
-    // iteration count limit in case there is crazy code.
-    unsigned Iteration = 0;
-    bool DevirtualizedCall = false;
-    do {
-      DEBUG(if (Iteration)
-              dbgs() << "  SCCPASSMGR: Re-visiting SCC, iteration #"
-                     << Iteration << '\n');
-      DevirtualizedCall = false;
-      Changed |= RunAllPassesOnSCC(CurSCC, CG, DevirtualizedCall);
-    } while (Iteration++ < MaxIterations && DevirtualizedCall);
-    
-    if (DevirtualizedCall)
-      DEBUG(dbgs() << "  CGSCCPASSMGR: Stopped iteration after " << Iteration
-                   << " times, due to -max-cg-scc-iterations\n");
-    
-    if (Iteration > MaxSCCIterations)
-      MaxSCCIterations = Iteration;
-    
-  }
-  Changed |= doFinalization(CG);
-  return Changed;
-}
-
-
-/// Initialize CG
-bool CGPassManager::doInitialization(CallGraph &CG) {
-  bool Changed = false;
-  for (unsigned i = 0, e = getNumContainedPasses(); i != e; ++i) {  
-    if (PMDataManager *PM = getContainedPass(i)->getAsPMDataManager()) {
-      assert(PM->getPassManagerType() == PMT_FunctionPassManager &&
-             "Invalid CGPassManager member");
-      Changed |= ((FPPassManager*)PM)->doInitialization(CG.getModule());
-    } else {
-      Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doInitialization(CG);
-    }
-  }
-  return Changed;
-}
-
-/// Finalize CG
-bool CGPassManager::doFinalization(CallGraph &CG) {
-  bool Changed = false;
-  for (unsigned i = 0, e = getNumContainedPasses(); i != e; ++i) {  
-    if (PMDataManager *PM = getContainedPass(i)->getAsPMDataManager()) {
-      assert(PM->getPassManagerType() == PMT_FunctionPassManager &&
-             "Invalid CGPassManager member");
-      Changed |= ((FPPassManager*)PM)->doFinalization(CG.getModule());
-    } else {
-      Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doFinalization(CG);
-    }
-  }
-  return Changed;
-}
-
-//===----------------------------------------------------------------------===//
-// CallGraphSCC Implementation
-//===----------------------------------------------------------------------===//
-
-/// This informs the SCC and the pass manager that the specified
-/// Old node has been deleted, and New is to be used in its place.
-void CallGraphSCC::ReplaceNode(CallGraphNode *Old, CallGraphNode *New) {
-  assert(Old != New && "Should not replace node with self");
-  for (unsigned i = 0; ; ++i) {
-    assert(i != Nodes.size() && "Node not in SCC");
-    if (Nodes[i] != Old) continue;
-    Nodes[i] = New;
-    break;
-  }
-  
-  // Update the active scc_iterator so that it doesn't contain dangling
-  // pointers to the old CallGraphNode.
-  scc_iterator<CallGraph*> *CGI = (scc_iterator<CallGraph*>*)Context;
-  CGI->ReplaceNode(Old, New);
-}
-
-
-//===----------------------------------------------------------------------===//
-// CallGraphSCCPass Implementation
-//===----------------------------------------------------------------------===//
-
-/// Assign pass manager to manage this pass.
-void CallGraphSCCPass::assignPassManager(PMStack &PMS,
-                                         PassManagerType PreferredType) {
-  // Find CGPassManager 
-  while (!PMS.empty() &&
-         PMS.top()->getPassManagerType() > PMT_CallGraphPassManager)
-    PMS.pop();
-
-  assert(!PMS.empty() && "Unable to handle Call Graph Pass");
-  CGPassManager *CGP;
-  
-  if (PMS.top()->getPassManagerType() == PMT_CallGraphPassManager)
-    CGP = (CGPassManager*)PMS.top();
-  else {
-    // Create new Call Graph SCC Pass Manager if it does not exist. 
-    assert(!PMS.empty() && "Unable to create Call Graph Pass Manager");
-    PMDataManager *PMD = PMS.top();
-
-    // [1] Create new Call Graph Pass Manager
-    CGP = new CGPassManager();
-
-    // [2] Set up new manager's top level manager
-    PMTopLevelManager *TPM = PMD->getTopLevelManager();
-    TPM->addIndirectPassManager(CGP);
-
-    // [3] Assign manager to manage this new manager. This may create
-    // and push new managers into PMS
-    Pass *P = CGP;
-    TPM->schedulePass(P);
-
-    // [4] Push new manager into PMS
-    PMS.push(CGP);
-  }
-
-  CGP->add(this);
-}
-
-/// For this class, we declare that we require and preserve the call graph.
-/// If the derived class implements this method, it should
-/// always explicitly call the implementation here.
-void CallGraphSCCPass::getAnalysisUsage(AnalysisUsage &AU) const {
-  AU.addRequired<CallGraphWrapperPass>();
-  AU.addPreserved<CallGraphWrapperPass>();
-}
-
-
-//===----------------------------------------------------------------------===//
-// PrintCallGraphPass Implementation
-//===----------------------------------------------------------------------===//
-
-namespace {
-  /// PrintCallGraphPass - Print a Module corresponding to a call graph.
-  ///
-  class PrintCallGraphPass : public CallGraphSCCPass {
-    std::string Banner;
-    raw_ostream &Out;       // raw_ostream to print on.
-    
-  public:
-    static char ID;
-    PrintCallGraphPass(const std::string &B, raw_ostream &o)
-      : CallGraphSCCPass(ID), Banner(B), Out(o) {}
-
-    void getAnalysisUsage(AnalysisUsage &AU) const override {
-      AU.setPreservesAll();
-    }
-
-    bool runOnSCC(CallGraphSCC &SCC) override {
-      Out << Banner;
-      for (CallGraphNode *CGN : SCC) {
-        if (CGN->getFunction())
-          CGN->getFunction()->print(Out);
-        else
-          Out << "\nPrinting <null> Function\n";
-      }
-      return false;
-    }
-  };
-  
-} // end anonymous namespace.
-
-char PrintCallGraphPass::ID = 0;
-
-Pass *CallGraphSCCPass::createPrinterPass(raw_ostream &O,
-                                          const std::string &Banner) const {
-  return new PrintCallGraphPass(Banner, O);
-}
-

llvm/trunk/lib/Analysis/IPA/CallPrinter.cpp

-//===- CallPrinter.cpp - DOT printer for call graph -----------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file defines '-dot-callgraph', which emit a callgraph.<fnname>.dot
-// containing the call graph of a module.
-//
-// There is also a pass available to directly call dotty ('-view-callgraph').
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Analysis/CallGraph.h"
-#include "llvm/Analysis/CallPrinter.h"
-#include "llvm/Analysis/DOTGraphTraitsPass.h"
-
-using namespace llvm;
-
-namespace llvm {
-
-template <> struct DOTGraphTraits<CallGraph *> : public DefaultDOTGraphTraits {
-  DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}
-
-  static std::string getGraphName(CallGraph *Graph) { return "Call graph"; }
-
-  std::string getNodeLabel(CallGraphNode *Node, CallGraph *Graph) {
-    if (Function *Func = Node->getFunction())
-      return Func->getName();
-
-    return "external node";
-  }
-};
-
-struct AnalysisCallGraphWrapperPassTraits {
-  static CallGraph *getGraph(CallGraphWrapperPass *P) {
-    return &P->getCallGraph();
-  }
-};
-
-} // end llvm namespace
-
-namespace {
-
-struct CallGraphViewer
-    : public DOTGraphTraitsModuleViewer<CallGraphWrapperPass, true, CallGraph *,
-                                        AnalysisCallGraphWrapperPassTraits> {
-  static char ID;
-
-  CallGraphViewer()
-      : DOTGraphTraitsModuleViewer<CallGraphWrapperPass, true, CallGraph *,
-                                   AnalysisCallGraphWrapperPassTraits>(
-            "callgraph", ID) {
-    initializeCallGraphViewerPass(*PassRegistry::getPassRegistry());
-  }
-};
-
-struct CallGraphPrinter : public DOTGraphTraitsModulePrinter<
-                              CallGraphWrapperPass, true, CallGraph *,
-                              AnalysisCallGraphWrapperPassTraits> {
-  static char ID;
-
-  CallGraphPrinter()
-      : DOTGraphTraitsModulePrinter<CallGraphWrapperPass, true, CallGraph *,
-                                    AnalysisCallGraphWrapperPassTraits>(
-            "callgraph", ID) {
-    initializeCallGraphPrinterPass(*PassRegistry::getPassRegistry());
-  }
-};
-
-} // end anonymous namespace
-
-char CallGraphViewer::ID = 0;
-INITIALIZE_PASS(CallGraphViewer, "view-callgraph", "View call graph", false,
-                false)
-
-char CallGraphPrinter::ID = 0;
-INITIALIZE_PASS(CallGraphPrinter, "dot-callgraph",
-                "Print call graph to 'dot' file", false, false)
-
-// Create methods available outside of this file, to use them
-// "include/llvm/LinkAllPasses.h". Otherwise the pass would be deleted by
-// the link time optimization.
-
-ModulePass *llvm::createCallGraphViewerPass() { return new CallGraphViewer(); }
-
-ModulePass *llvm::createCallGraphPrinterPass() {
-  return new CallGraphPrinter();
-}

llvm/trunk/lib/Analysis/IPA/GlobalsModRef.cpp

-//===- GlobalsModRef.cpp - Simple Mod/Ref Analysis for Globals ------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This simple pass provides alias and mod/ref information for global values
-// that do not have their address taken, and keeps track of whether functions
-// read or write memory (are "pure").  For this simple (but very common) case,
-// we can provide pretty accurate and useful information.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Analysis/GlobalsModRef.h"
-#include "llvm/ADT/SCCIterator.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Analysis/MemoryBuiltins.h"
-#include "llvm/Analysis/ValueTracking.h"
-#include "llvm/IR/DerivedTypes.h"
-#include "llvm/IR/InstIterator.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/IntrinsicInst.h"
-#include "llvm/IR/Module.h"
-#include "llvm/Pass.h"
-#include "llvm/Support/CommandLine.h"
-using namespace llvm;
-
-#define DEBUG_TYPE "globalsmodref-aa"
-
-STATISTIC(NumNonAddrTakenGlobalVars,
-          "Number of global vars without address taken");
-STATISTIC(NumNonAddrTakenFunctions,"Number of functions without address taken");
-STATISTIC(NumNoMemFunctions, "Number of functions that do not access memory");
-STATISTIC(NumReadMemFunctions, "Number of functions that only read memory");
-STATISTIC(NumIndirectGlobalVars, "Number of indirect global objects");
-
-// An option to enable unsafe alias results from the GlobalsModRef analysis.
-// When enabled, GlobalsModRef will provide no-alias results which in extremely
-// rare cases may not be conservatively correct. In particular, in the face of
-// transforms which cause assymetry between how effective GetUnderlyingObject
-// is for two pointers, it may produce incorrect results.
-//
-// These unsafe results have been returned by GMR for many years without
-// causing significant issues in the wild and so we provide a mechanism to
-// re-enable them for users of LLVM that have a particular performance
-// sensitivity and no known issues. The option also makes it easy to evaluate
-// the performance impact of these results.
-static cl::opt<bool> EnableUnsafeGlobalsModRefAliasResults(
-    "enable-unsafe-globalsmodref-alias-results", cl::init(false), cl::Hidden);
-
-/// The mod/ref information collected for a particular function.
-///
-/// We collect information about mod/ref behavior of a function here, both in
-/// general and as pertains to specific globals. We only have this detailed
-/// information when we know *something* useful about the behavior. If we
-/// saturate to fully general mod/ref, we remove the info for the function.
-class GlobalsModRef::FunctionInfo {
-  typedef SmallDenseMap<const GlobalValue *, ModRefInfo, 16> GlobalInfoMapType;
-
-  /// Build a wrapper struct that has 8-byte alignment. All heap allocations
-  /// should provide this much alignment at least, but this makes it clear we
-  /// specifically rely on this amount of alignment.
-  struct LLVM_ALIGNAS(8) AlignedMap {
-    AlignedMap() {}
-    AlignedMap(const AlignedMap &Arg) : Map(Arg.Map) {}
-    GlobalInfoMapType Map;
-  };
-
-  /// Pointer traits for our aligned map.
-  struct AlignedMapPointerTraits {
-    static inline void *getAsVoidPointer(AlignedMap *P) { return P; }
-    static inline AlignedMap *getFromVoidPointer(void *P) {
-      return (AlignedMap *)P;
-    }
-    enum { NumLowBitsAvailable = 3 };
-    static_assert(AlignOf<AlignedMap>::Alignment >= (1 << NumLowBitsAvailable),
-                  "AlignedMap insufficiently aligned to have enough low bits.");
-  };
-
-  /// The bit that flags that this function may read any global. This is
-  /// chosen to mix together with ModRefInfo bits.
-  enum { MayReadAnyGlobal = 4 };
-
-  /// Checks to document the invariants of the bit packing here.
-  static_assert((MayReadAnyGlobal & MRI_ModRef) == 0,
-                "ModRef and the MayReadAnyGlobal flag bits overlap.");
-  static_assert(((MayReadAnyGlobal | MRI_ModRef) >>
-                 AlignedMapPointerTraits::NumLowBitsAvailable) == 0,
-                "Insufficient low bits to store our flag and ModRef info.");
-
-public:
-  FunctionInfo() : Info() {}
-  ~FunctionInfo() {
-    delete Info.getPointer();
-  }
-  // Spell out the copy ond move constructors and assignment operators to get
-  // deep copy semantics and correct move semantics in the face of the
-  // pointer-int pair.
-  FunctionInfo(const FunctionInfo &Arg)
-      : Info(nullptr, Arg.Info.getInt()) {
-    if (const auto *ArgPtr = Arg.Info.getPointer())
-      Info.setPointer(new AlignedMap(*ArgPtr));
-  }
-  FunctionInfo(FunctionInfo &&Arg)
-      : Info(Arg.Info.getPointer(), Arg.Info.getInt()) {
-    Arg.Info.setPointerAndInt(nullptr, 0);
-  }
-  FunctionInfo &operator=(const FunctionInfo &RHS) {
-    delete Info.getPointer();
-    Info.setPointerAndInt(nullptr, RHS.Info.getInt());
-    if (const auto *RHSPtr = RHS.Info.getPointer())
-      Info.setPointer(new AlignedMap(*RHSPtr));
-    return *this;
-  }
-  FunctionInfo &operator=(FunctionInfo &&RHS) {
-    delete Info.getPointer();
-    Info.setPointerAndInt(RHS.Info.getPointer(), RHS.Info.getInt());
-    RHS.Info.setPointerAndInt(nullptr, 0);
-    return *this;
-  }
-
-  /// Returns the \c ModRefInfo info for this function.
-  ModRefInfo getModRefInfo() const {
-    return ModRefInfo(Info.getInt() & MRI_ModRef);
-  }
-
-  /// Adds new \c ModRefInfo for this function to its state.
-  void addModRefInfo(ModRefInfo NewMRI) {
-    Info.setInt(Info.getInt() | NewMRI);
-  }
-
-  /// Returns whether this function may read any global variable, and we don't
-  /// know which global.
-  bool mayReadAnyGlobal() const { return Info.getInt() & MayReadAnyGlobal; }
-
-  /// Sets this function as potentially reading from any global.
-  void setMayReadAnyGlobal() { Info.setInt(Info.getInt() | MayReadAnyGlobal); }
-
-  /// Returns the \c ModRefInfo info for this function w.r.t. a particular
-  /// global, which may be more precise than the general information above.
-  ModRefInfo getModRefInfoForGlobal(const GlobalValue &GV) const {
-    ModRefInfo GlobalMRI = mayReadAnyGlobal() ? MRI_Ref : MRI_NoModRef;
-    if (AlignedMap *P = Info.getPointer()) {
-      auto I = P->Map.find(&GV);
-      if (I != P->Map.end())
-        GlobalMRI = ModRefInfo(GlobalMRI | I->second);
-    }
-    return GlobalMRI;
-  }
-
-  /// Add mod/ref info from another function into ours, saturating towards
-  /// MRI_ModRef.
-  void addFunctionInfo(const FunctionInfo &FI) {
-    addModRefInfo(FI.getModRefInfo());
-
-    if (FI.mayReadAnyGlobal())
-      setMayReadAnyGlobal();
-
-    if (AlignedMap *P = FI.Info.getPointer())
-      for (const auto &G : P->Map)
-        addModRefInfoForGlobal(*G.first, G.second);
-  }
-
-  void addModRefInfoForGlobal(const GlobalValue &GV, ModRefInfo NewMRI) {
-    AlignedMap *P = Info.getPointer();
-    if (!P) {
-      P = new AlignedMap();
-      Info.setPointer(P);
-    }
-    auto &GlobalMRI = P->Map[&GV];
-    GlobalMRI = ModRefInfo(GlobalMRI | NewMRI);
-  }
-
-  /// Clear a global's ModRef info. Should be used when a global is being
-  /// deleted.
-  void eraseModRefInfoForGlobal(const GlobalValue &GV) {
-    if (AlignedMap *P = Info.getPointer())
-      P->Map.erase(&GV);
-  }
-
-private:
-  /// All of the information is encoded into a single pointer, with a three bit
-  /// integer in the low three bits. The high bit provides a flag for when this
-  /// function may read any global. The low two bits are the ModRefInfo. And
-  /// the pointer, when non-null, points to a map from GlobalValue to
-  /// ModRefInfo specific to that GlobalValue.
-  PointerIntPair<AlignedMap *, 3, unsigned, AlignedMapPointerTraits> Info;
-};
-
-void GlobalsModRef::DeletionCallbackHandle::deleted() {
-  Value *V = getValPtr();
-  if (auto *F = dyn_cast<Function>(V))
-    GMR.FunctionInfos.erase(F);
-
-  if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
-    if (GMR.NonAddressTakenGlobals.erase(GV)) {
-      // This global might be an indirect global.  If so, remove it and
-      // remove any AllocRelatedValues for it.
-      if (GMR.IndirectGlobals.erase(GV)) {
-        // Remove any entries in AllocsForIndirectGlobals for this global.
-        for (auto I = GMR.AllocsForIndirectGlobals.begin(),
-                  E = GMR.AllocsForIndirectGlobals.end();
-             I != E; ++I)
-          if (I->second == GV)
-            GMR.AllocsForIndirectGlobals.erase(I);
-      }
-
-      // Scan the function info we have collected and remove this global
-      // from all of them.
-      for (auto &FIPair : GMR.FunctionInfos)
-        FIPair.second.eraseModRefInfoForGlobal(*GV);
-    }
-  }
-
-  // If this is an allocation related to an indirect global, remove it.
-  GMR.AllocsForIndirectGlobals.erase(V);
-
-  // And clear out the handle.
-  setValPtr(nullptr);
-  GMR.Handles.erase(I);
-  // This object is now destroyed!
-}
-
-char GlobalsModRef::ID = 0;
-INITIALIZE_AG_PASS_BEGIN(GlobalsModRef, AliasAnalysis, "globalsmodref-aa",
-                         "Simple mod/ref analysis for globals", false, true,
-                         false)
-INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
-INITIALIZE_AG_PASS_END(GlobalsModRef, AliasAnalysis, "globalsmodref-aa",
-                       "Simple mod/ref analysis for globals", false, true,
-                       false)
-
-Pass *llvm::createGlobalsModRefPass() { return new GlobalsModRef(); }
-
-GlobalsModRef::GlobalsModRef() : ModulePass(ID) {
-  initializeGlobalsModRefPass(*PassRegistry::getPassRegistry());
-}
-
-FunctionModRefBehavior GlobalsModRef::getModRefBehavior(const Function *F) {
-  FunctionModRefBehavior Min = FMRB_UnknownModRefBehavior;
-
-  if (FunctionInfo *FI = getFunctionInfo(F)) {
-    if (FI->getModRefInfo() == MRI_NoModRef)
-      Min = FMRB_DoesNotAccessMemory;
-    else if ((FI->getModRefInfo() & MRI_Mod) == 0)
-      Min = FMRB_OnlyReadsMemory;
-  }
-
-  return FunctionModRefBehavior(AliasAnalysis::getModRefBehavior(F) & Min);
-}
-
-FunctionModRefBehavior GlobalsModRef::getModRefBehavior(ImmutableCallSite CS) {
-  FunctionModRefBehavior Min = FMRB_UnknownModRefBehavior;
-
-  if (const Function *F = CS.getCalledFunction())
-    if (FunctionInfo *FI = getFunctionInfo(F)) {
-      if (FI->getModRefInfo() == MRI_NoModRef)
-        Min = FMRB_DoesNotAccessMemory;
-      else if ((FI->getModRefInfo() & MRI_Mod) == 0)
-        Min = FMRB_OnlyReadsMemory;
-    }
-
-  return FunctionModRefBehavior(AliasAnalysis::getModRefBehavior(CS) & Min);
-}
-
-/// Returns the function info for the function, or null if we don't have
-/// anything useful to say about it.
-GlobalsModRef::FunctionInfo *GlobalsModRef::getFunctionInfo(const Function *F) {
-  auto I = FunctionInfos.find(F);
-  if (I != FunctionInfos.end())
-    return &I->second;
-  return nullptr;
-}
-
-/// AnalyzeGlobals - Scan through the users of all of the internal
-/// GlobalValue's in the program.  If none of them have their "address taken"
-/// (really, their address passed to something nontrivial), record this fact,
-/// and record the functions that they are used directly in.
-void GlobalsModRef::AnalyzeGlobals(Module &M) {
-  SmallPtrSet<Function *, 64> TrackedFunctions;
-  for (Function &F : M)
-    if (F.hasLocalLinkage())
-      if (!AnalyzeUsesOfPointer(&F)) {
-        // Remember that we are tracking this global.
-        NonAddressTakenGlobals.insert(&F);
-        TrackedFunctions.insert(&F);
-        Handles.emplace_front(*this, &F);
-        Handles.front().I = Handles.begin();
-        ++NumNonAddrTakenFunctions;
-      }
-
-  SmallPtrSet<Function *, 64> Readers, Writers;
-  for (GlobalVariable &GV : M.globals())
-    if (GV.hasLocalLinkage()) {
-      if (!AnalyzeUsesOfPointer(&GV, &Readers,
-                                GV.isConstant() ? nullptr : &Writers)) {
-        // Remember that we are tracking this global, and the mod/ref fns
-        NonAddressTakenGlobals.insert(&GV);
-        Handles.emplace_front(*this, &GV);
-        Handles.front().I = Handles.begin();
-
-        for (Function *Reader : Readers) {
-          if (TrackedFunctions.insert(Reader).second) {
-            Handles.emplace_front(*this, Reader);
-            Handles.front().I = Handles.begin();
-          }
-          FunctionInfos[Reader].addModRefInfoForGlobal(GV, MRI_Ref);
-        }
-
-        if (!GV.isConstant()) // No need to keep track of writers to constants
-          for (Function *Writer : Writers) {
-            if (TrackedFunctions.insert(Writer).second) {
-              Handles.emplace_front(*this, Writer);
-              Handles.front().I = Handles.begin();
-            }
-            FunctionInfos[Writer].addModRefInfoForGlobal(GV, MRI_Mod);
-          }
-        ++NumNonAddrTakenGlobalVars;
-
-        // If this global holds a pointer type, see if it is an indirect global.
-        if (GV.getType()->getElementType()->isPointerTy() &&
-            AnalyzeIndirectGlobalMemory(&GV))
-          ++NumIndirectGlobalVars;
-      }
-      Readers.clear();
-      Writers.clear();
-    }
-}
-
-/// AnalyzeUsesOfPointer - Look at all of the users of the specified pointer.
-/// If this is used by anything complex (i.e., the address escapes), return
-/// true.  Also, while we are at it, keep track of those functions that read and
-/// write to the value.
-///
-/// If OkayStoreDest is non-null, stores into this global are allowed.
-bool GlobalsModRef::AnalyzeUsesOfPointer(Value *V,
-                                         SmallPtrSetImpl<Function *> *Readers,
-                                         SmallPtrSetImpl<Function *> *Writers,
-                                         GlobalValue *OkayStoreDest) {
-  if (!V->getType()->isPointerTy())
-    return true;
-
-  for (Use &U : V->uses()) {
-    User *I = U.getUser();
-    if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
-      if (Readers)
-        Readers->insert(LI->getParent()->getParent());
-    } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
-      if (V == SI->getOperand(1)) {
-        if (Writers)
-          Writers->insert(SI->getParent()->getParent());
-      } else if (SI->getOperand(1) != OkayStoreDest) {
-        return true; // Storing the pointer
-      }
-    } else if (Operator::getOpcode(I) == Instruction::GetElementPtr) {
-      if (AnalyzeUsesOfPointer(I, Readers, Writers))
-        return true;
-    } else if (Operator::getOpcode(I) == Instruction::BitCast) {
-      if (AnalyzeUsesOfPointer(I, Readers, Writers, OkayStoreDest))
-        return true;
-    } else if (auto CS = CallSite(I)) {
-      // Make sure that this is just the function being called, not that it is
-      // passing into the function.
-      if (!CS.isCallee(&U)) {
-        // Detect calls to free.
-        if (isFreeCall(I, TLI)) {
-          if (Writers)
-            Writers->insert(CS->getParent()->getParent());
-        } else {
-          return true; // Argument of an unknown call.
-        }
-      }
-    } else if (ICmpInst *ICI = dyn_cast<ICmpInst>(I)) {
-      if (!isa<ConstantPointerNull>(ICI->getOperand(1)))
-        return true; // Allow comparison against null.
-    } else {
-      return true;
-    }
-  }
-
-  return false;
-}
-
-/// AnalyzeIndirectGlobalMemory - We found an non-address-taken global variable
-/// which holds a pointer type.  See if the global always points to non-aliased
-/// heap memory: that is, all initializers of the globals are allocations, and
-/// those allocations have no use other than initialization of the global.
-/// Further, all loads out of GV must directly use the memory, not store the
-/// pointer somewhere.  If this is true, we consider the memory pointed to by
-/// GV to be owned by GV and can disambiguate other pointers from it.
-bool GlobalsModRef::AnalyzeIndirectGlobalMemory(GlobalValue *GV) {
-  // Keep track of values related to the allocation of the memory, f.e. the
-  // value produced by the malloc call and any casts.
-  std::vector<Value *> AllocRelatedValues;
-
-  // Walk the user list of the global.  If we find anything other than a direct
-  // load or store, bail out.
-  for (User *U : GV->users()) {
-    if (LoadInst *LI = dyn_cast<LoadInst>(U)) {
-      // The pointer loaded from the global can only be used in simple ways:
-      // we allow addressing of it and loading storing to it.  We do *not* allow
-      // storing the loaded pointer somewhere else or passing to a function.
-      if (AnalyzeUsesOfPointer(LI))
-        return false; // Loaded pointer escapes.
-      // TODO: Could try some IP mod/ref of the loaded pointer.
-    } else if (StoreInst *SI = dyn_cast<StoreInst>(U)) {
-      // Storing the global itself.
-      if (SI->getOperand(0) == GV)
-        return false;
-
-      // If storing the null pointer, ignore it.
-      if (isa<ConstantPointerNull>(SI->getOperand(0)))
-        continue;
-
-      // Check the value being stored.
-      Value *Ptr = GetUnderlyingObject(SI->getOperand(0),
-                                       GV->getParent()->getDataLayout());
-
-      if (!isAllocLikeFn(Ptr, TLI))
-        return false; // Too hard to analyze.
-
-      // Analyze all uses of the allocation.  If any of them are used in a
-      // non-simple way (e.g. stored to another global) bail out.
-      if (AnalyzeUsesOfPointer(Ptr, /*Readers*/ nullptr, /*Writers*/ nullptr,
-                               GV))
-        return false; // Loaded pointer escapes.
-
-      // Remember that this allocation is related to the indirect global.
-      AllocRelatedValues.push_back(Ptr);
-    } else {
-      // Something complex, bail out.
-      return false;
-    }
-  }
-
-  // Okay, this is an indirect global.  Remember all of the allocations for
-  // this global in AllocsForIndirectGlobals.
-  while (!AllocRelatedValues.empty()) {
-    AllocsForIndirectGlobals[AllocRelatedValues.back()] = GV;
-    Handles.emplace_front(*this, AllocRelatedValues.back());
-    Handles.front().I = Handles.begin();
-    AllocRelatedValues.pop_back();
-  }
-  IndirectGlobals.insert(GV);
-  Handles.emplace_front(*this, GV);
-  Handles.front().I = Handles.begin();
-  return true;
-}
-
-/// AnalyzeCallGraph - At this point, we know the functions where globals are
-/// immediately stored to and read from.  Propagate this information up the call
-/// graph to all callers and compute the mod/ref info for all memory for each
-/// function.
-void GlobalsModRef::AnalyzeCallGraph(CallGraph &CG, Module &M) {
-  // We do a bottom-up SCC traversal of the call graph.  In other words, we
-  // visit all callees before callers (leaf-first).
-  for (scc_iterator<CallGraph *> I = scc_begin(&CG); !I.isAtEnd(); ++I) {
-    const std::vector<CallGraphNode *> &SCC = *I;
-    assert(!SCC.empty() && "SCC with no functions?");
-
-    if (!SCC[0]->getFunction()) {
-      // Calls externally - can't say anything useful.  Remove any existing
-      // function records (may have been created when scanning globals).
-      for (auto *Node : SCC)
-        FunctionInfos.erase(Node->getFunction());
-      continue;
-    }
-
-    FunctionInfo &FI = FunctionInfos[SCC[0]->getFunction()];
-    bool KnowNothing = false;
-
-    // Collect the mod/ref properties due to called functions.  We only compute
-    // one mod-ref set.
-    for (unsigned i = 0, e = SCC.size(); i != e && !KnowNothing; ++i) {
-      Function *F = SCC[i]->getFunction();
-      if (!F) {
-        KnowNothing = true;
-        break;
-      }
-
-      if (F->isDeclaration()) {
-        // Try to get mod/ref behaviour from function attributes.
-        if (F->doesNotAccessMemory()) {
-          // Can't do better than that!
-        } else if (F->onlyReadsMemory()) {
-          FI.addModRefInfo(MRI_Ref);
-          if (!F->isIntrinsic())
-            // This function might call back into the module and read a global -
-            // consider every global as possibly being read by this function.
-            FI.setMayReadAnyGlobal();
-        } else {
-          FI.addModRefInfo(MRI_ModRef);
-          // Can't say anything useful unless it's an intrinsic - they don't
-          // read or write global variables of the kind considered here.
-          KnowNothing = !F->isIntrinsic();
-        }
-        continue;
-      }
-
-      for (CallGraphNode::iterator CI = SCC[i]->begin(), E = SCC[i]->end();
-           CI != E && !KnowNothing; ++CI)
-        if (Function *Callee = CI->second->getFunction()) {
-          if (FunctionInfo *CalleeFI = getFunctionInfo(Callee)) {
-            // Propagate function effect up.
-            FI.addFunctionInfo(*CalleeFI);
-          } else {
-            // Can't say anything about it.  However, if it is inside our SCC,
-            // then nothing needs to be done.
-            CallGraphNode *CalleeNode = CG[Callee];
-            if (std::find(SCC.begin(), SCC.end(), CalleeNode) == SCC.end())
-              KnowNothing = true;
-          }
-        } else {
-          KnowNothing = true;
-        }
-    }
-
-    // If we can't say anything useful about this SCC, remove all SCC functions
-    // from the FunctionInfos map.
-    if (KnowNothing) {
-      for (auto *Node : SCC)
-        FunctionInfos.erase(Node->getFunction());
-      continue;
-    }
-
-    // Scan the function bodies for explicit loads or stores.
-    for (auto *Node : SCC) {
-      if (FI.getModRefInfo() == MRI_ModRef)
-        break; // The mod/ref lattice saturates here.
-      for (Instruction &I : instructions(Node->getFunction())) {
-        if (FI.getModRefInfo() == MRI_ModRef)
-          break; // The mod/ref lattice saturates here.
-
-        // We handle calls specially because the graph-relevant aspects are
-        // handled above.
-        if (auto CS = CallSite(&I)) {
-          if (isAllocationFn(&I, TLI) || isFreeCall(&I, TLI)) {
-            // FIXME: It is completely unclear why this is necessary and not
-            // handled by the above graph code.
-            FI.addModRefInfo(MRI_ModRef);
-          } else if (Function *Callee = CS.getCalledFunction()) {
-            // The callgraph doesn't include intrinsic calls.
-            if (Callee->isIntrinsic()) {
-              FunctionModRefBehavior Behaviour =
-                  AliasAnalysis::getModRefBehavior(Callee);
-              FI.addModRefInfo(ModRefInfo(Behaviour & MRI_ModRef));
-            }
-          }
-          continue;
-        }
-
-        // All non-call instructions we use the primary predicates for whether
-        // thay read or write memory.
-        if (I.mayReadFromMemory())
-          FI.addModRefInfo(MRI_Ref);
-        if (I.mayWriteToMemory())
-          FI.addModRefInfo(MRI_Mod);
-      }
-    }
-
-    if ((FI.getModRefInfo() & MRI_Mod) == 0)
-      ++NumReadMemFunctions;
-    if (FI.getModRefInfo() == MRI_NoModRef)
-      ++NumNoMemFunctions;
-
-    // Finally, now that we know the full effect on this SCC, clone the
-    // information to each function in the SCC.
-    for (unsigned i = 1, e = SCC.size(); i != e; ++i)
-      FunctionInfos[SCC[i]->getFunction()] = FI;
-  }
-}
-
-// There are particular cases where we can conclude no-alias between
-// a non-addr-taken global and some other underlying object. Specifically,
-// a non-addr-taken global is known to not be escaped from any function. It is
-// also incorrect for a transformation to introduce an escape of a global in
-// a way that is observable when it was not there previously. One function
-// being transformed to introduce an escape which could possibly be observed
-// (via loading from a global or the return value for example) within another
-// function is never safe. If the observation is made through non-atomic
-// operations on different threads, it is a data-race and UB. If the
-// observation is well defined, by being observed the transformation would have
-// changed program behavior by introducing the observed escape, making it an
-// invalid transform.
-//
-// This property does require that transformations which *temporarily* escape
-// a global that was not previously escaped, prior to restoring it, cannot rely
-// on the results of GMR::alias. This seems a reasonable restriction, although
-// currently there is no way to enforce it. There is also no realistic
-// optimization pass that would make this mistake. The closest example is
-// a transformation pass which does reg2mem of SSA values but stores them into
-// global variables temporarily before restoring the global variable's value.
-// This could be useful to expose "benign" races for example. However, it seems
-// reasonable to require that a pass which introduces escapes of global
-// variables in this way to either not trust AA results while the escape is
-// active, or to be forced to operate as a module pass that cannot co-exist
-// with an alias analysis such as GMR.
-bool GlobalsModRef::isNonEscapingGlobalNoAlias(const GlobalValue *GV,
-                                               const Value *V) {
-  // In order to know that the underlying object cannot alias the
-  // non-addr-taken global, we must know that it would have to be an escape.
-  // Thus if the underlying object is a function argument, a load from
-  // a global, or the return of a function, it cannot alias. We can also
-  // recurse through PHI nodes and select nodes provided all of their inputs
-  // resolve to one of these known-escaping roots.
-  SmallPtrSet<const Value *, 8> Visited;
-  SmallVector<const Value *, 8> Inputs;
-  Visited.insert(V);
-  Inputs.push_back(V);
-  int Depth = 0;
-  do {
-    const Value *Input = Inputs.pop_back_val();
-
-    if (auto *InputGV = dyn_cast<GlobalValue>(Input)) {
-      // If one input is the very global we're querying against, then we can't
-      // conclude no-alias.
-      if (InputGV == GV)
-        return false;
-
-      // Distinct GlobalVariables never alias, unless overriden or zero-sized.
-      // FIXME: The condition can be refined, but be conservative for now.
-      auto *GVar = dyn_cast<GlobalVariable>(GV);
-      auto *InputGVar = dyn_cast<GlobalVariable>(InputGV);
-      if (GVar && InputGVar &&
-          !GVar->isDeclaration() && !InputGVar->isDeclaration() &&
-          !GVar->mayBeOverridden() && !InputGVar->mayBeOverridden()) {
-        Type *GVType = GVar->getInitializer()->getType();
-        Type *InputGVType = InputGVar->getInitializer()->getType();
-        if (GVType->isSized() && InputGVType->isSized() &&
-            (DL->getTypeAllocSize(GVType) > 0) &&
-            (DL->getTypeAllocSize(InputGVType) > 0))
-          continue;
-      }
-
-      // Conservatively return false, even though we could be smarter
-      // (e.g. look through GlobalAliases).
-      return false;
-    }
-
-    if (isa<Argument>(Input) || isa<CallInst>(Input) ||
-        isa<InvokeInst>(Input)) {
-      // Arguments to functions or returns from functions are inherently
-      // escaping, so we can immediately classify those as not aliasing any
-      // non-addr-taken globals.
-      continue;
-    }
-    if (auto *LI = dyn_cast<LoadInst>(Input)) {
-      // A pointer loaded from a global would have been captured, and we know
-      // that the global is non-escaping, so no alias.
-      if (isa<GlobalValue>(GetUnderlyingObject(LI->getPointerOperand(), *DL)))
-        continue;
-
-      // Otherwise, a load could come from anywhere, so bail.
-      return false;
-    }
-
-    // Recurse through a limited number of selects and PHIs. This is an
-    // arbitrary depth of 4, lower numbers could be used to fix compile time
-    // issues if needed, but this is generally expected to be only be important
-    // for small depths.
-    if (++Depth > 4)
-      return false;
-    if (auto *SI = dyn_cast<SelectInst>(Input)) {
-      const Value *LHS = GetUnderlyingObject(SI->getTrueValue(), *DL);
-      const Value *RHS = GetUnderlyingObject(SI->getFalseValue(), *DL);
-      if (Visited.insert(LHS).second)
-        Inputs.push_back(LHS);
-      if (Visited.insert(RHS).second)
-        Inputs.push_back(RHS);
-      continue;
-    }
-    if (auto *PN = dyn_cast<PHINode>(Input)) {
-      for (const Value *Op : PN->incoming_values()) {
-        Op = GetUnderlyingObject(Op, *DL);
-        if (Visited.insert(Op).second)
-          Inputs.push_back(Op);
-      }
-      continue;
-    }
-
-    // FIXME: It would be good to handle other obvious no-alias cases here, but
-    // it isn't clear how to do so reasonbly without building a small version
-    // of BasicAA into this code. We could recurse into AliasAnalysis::alias
-    // here but that seems likely to go poorly as we're inside the
-    // implementation of such a query. Until then, just conservatievly retun
-    // false.
-    return false;
-  } while (!Inputs.empty());
-
-  // If all the inputs to V were definitively no-alias, then V is no-alias.
-  return true;
-}
-
-/// alias - If one of the pointers is to a global that we are tracking, and the
-/// other is some random pointer, we know there cannot be an alias, because the
-/// address of the global isn't taken.
-AliasResult GlobalsModRef::alias(const MemoryLocation &LocA,
-                                 const MemoryLocation &LocB) {
-  // Get the base object these pointers point to.
-  const Value *UV1 = GetUnderlyingObject(LocA.Ptr, *DL);
-  const Value *UV2 = GetUnderlyingObject(LocB.Ptr, *DL);
-
-  // If either of the underlying values is a global, they may be non-addr-taken
-  // globals, which we can answer queries about.
-  const GlobalValue *GV1 = dyn_cast<GlobalValue>(UV1);
-  const GlobalValue *GV2 = dyn_cast<GlobalValue>(UV2);
-  if (GV1 || GV2) {
-    // If the global's address is taken, pretend we don't know it's a pointer to
-    // the global.
-    if (GV1 && !NonAddressTakenGlobals.count(GV1))
-      GV1 = nullptr;
-    if (GV2 && !NonAddressTakenGlobals.count(GV2))
-      GV2 = nullptr;
-
-    // If the two pointers are derived from two different non-addr-taken
-    // globals we know these can't alias.
-    if (GV1 && GV2 && GV1 != GV2)
-      return NoAlias;
-
-    // If one is and the other isn't, it isn't strictly safe but we can fake
-    // this result if necessary for performance. This does not appear to be
-    // a common problem in practice.
-    if (EnableUnsafeGlobalsModRefAliasResults)
-      if ((GV1 || GV2) && GV1 != GV2)
-        return NoAlias;
-
-    // Check for a special case where a non-escaping global can be used to
-    // conclude no-alias.
-    if ((GV1 || GV2) && GV1 != GV2) {
-      const GlobalValue *GV = GV1 ? GV1 : GV2;
-      const Value *UV = GV1 ? UV2 : UV1;
-      if (isNonEscapingGlobalNoAlias(GV, UV))
-        return NoAlias;
-    }
-
-    // Otherwise if they are both derived from the same addr-taken global, we
-    // can't know the two accesses don't overlap.
-  }
-
-  // These pointers may be based on the memory owned by an indirect global.  If
-  // so, we may be able to handle this.  First check to see if the base pointer
-  // is a direct load from an indirect global.
-  GV1 = GV2 = nullptr;
-  if (const LoadInst *LI = dyn_cast<LoadInst>(UV1))
-    if (GlobalVariable *GV = dyn_cast<GlobalVariable>(LI->getOperand(0)))
-      if (IndirectGlobals.count(GV))
-        GV1 = GV;
-  if (const LoadInst *LI = dyn_cast<LoadInst>(UV2))
-    if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(LI->getOperand(0)))
-      if (IndirectGlobals.count(GV))
-        GV2 = GV;
-
-  // These pointers may also be from an allocation for the indirect global.  If
-  // so, also handle them.
-  if (!GV1)
-    GV1 = AllocsForIndirectGlobals.lookup(UV1);
-  if (!GV2)
-    GV2 = AllocsForIndirectGlobals.lookup(UV2);
-
-  // Now that we know whether the two pointers are related to indirect globals,
-  // use this to disambiguate the pointers. If the pointers are based on
-  // different indirect globals they cannot alias.
-  if (GV1 && GV2 && GV1 != GV2)
-    return NoAlias;
-
-  // If one is based on an indirect global and the other isn't, it isn't
-  // strictly safe but we can fake this result if necessary for performance.
-  // This does not appear to be a common problem in practice.
-  if (EnableUnsafeGlobalsModRefAliasResults)
-    if ((GV1 || GV2) && GV1 != GV2)
-      return NoAlias;
-
-  return AliasAnalysis::alias(LocA, LocB);
-}
-
-ModRefInfo GlobalsModRef::getModRefInfo(ImmutableCallSite CS,
-                                        const MemoryLocation &Loc) {
-  unsigned Known = MRI_ModRef;
-
-  // If we are asking for mod/ref info of a direct call with a pointer to a
-  // global we are tracking, return information if we have it.
-  const DataLayout &DL = CS.getCaller()->getParent()->getDataLayout();
-  if (const GlobalValue *GV =
-          dyn_cast<GlobalValue>(GetUnderlyingObject(Loc.Ptr, DL)))
-    if (GV->hasLocalLinkage())
-      if (const Function *F = CS.getCalledFunction())
-        if (NonAddressTakenGlobals.count(GV))
-          if (const FunctionInfo *FI = getFunctionInfo(F))
-            Known = FI->getModRefInfoForGlobal(*GV);
-
-  if (Known == MRI_NoModRef)
-    return MRI_NoModRef; // No need to query other mod/ref analyses
-  return ModRefInfo(Known & AliasAnalysis::getModRefInfo(CS, Loc));
-}

llvm/trunk/lib/Analysis/IPA/IPA.cpp

-//===-- IPA.cpp -----------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the common initialization routines for the IPA library.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/InitializePasses.h"
-#include "llvm-c/Initialization.h"
-#include "llvm/PassRegistry.h"
-
-using namespace llvm;
-
-/// initializeIPA - Initialize all passes linked into the IPA library.
-void llvm::initializeIPA(PassRegistry &Registry) {
-  initializeCallGraphWrapperPassPass(Registry);
-  initializeCallGraphPrinterPass(Registry);
-  initializeCallGraphViewerPass(Registry);
-  initializeGlobalsModRefPass(Registry);
-}
-
-void LLVMInitializeIPA(LLVMPassRegistryRef R) {
-  initializeIPA(*unwrap(R));
-}

llvm/trunk/lib/Analysis/IPA/InlineCost.cpp

-//===- InlineCost.cpp - Cost analysis for inliner -------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements inline cost analysis.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Analysis/InlineCost.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SetVector.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Analysis/AssumptionCache.h"
-#include "llvm/Analysis/CodeMetrics.h"
-#include "llvm/Analysis/ConstantFolding.h"
-#include "llvm/Analysis/InstructionSimplify.h"
-#include "llvm/Analysis/TargetTransformInfo.h"
-#include "llvm/IR/CallSite.h"
-#include "llvm/IR/CallingConv.h"
-#include "llvm/IR/DataLayout.h"
-#include "llvm/IR/GetElementPtrTypeIterator.h"
-#include "llvm/IR/GlobalAlias.h"
-#include "llvm/IR/InstVisitor.h"
-#include "llvm/IR/IntrinsicInst.h"
-#include "llvm/IR/Operator.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/raw_ostream.h"
-
-using namespace llvm;
-
-#define DEBUG_TYPE "inline-cost"
-
-STATISTIC(NumCallsAnalyzed, "Number of call sites analyzed");
-
-namespace {
-
-class CallAnalyzer : public InstVisitor<CallAnalyzer, bool> {
-  typedef InstVisitor<CallAnalyzer, bool> Base;
-  friend class InstVisitor<CallAnalyzer, bool>;
-
-  /// The TargetTransformInfo available for this compilation.
-  const TargetTransformInfo &TTI;
-
-  /// The cache of @llvm.assume intrinsics.
-  AssumptionCacheTracker *ACT;
-
-  // The called function.
-  Function &F;
-
-  // The candidate callsite being analyzed. Please do not use this to do
-  // analysis in the caller function; we want the inline cost query to be
-  // easily cacheable. Instead, use the cover function paramHasAttr.
-  CallSite CandidateCS;
-
-  int Threshold;
-  int Cost;
-
-  bool IsCallerRecursive;
-  bool IsRecursiveCall;
-  bool ExposesReturnsTwice;
-  bool HasDynamicAlloca;
-  bool ContainsNoDuplicateCall;
-  bool HasReturn;
-  bool HasIndirectBr;
-  bool HasFrameEscape;
-
-  /// Number of bytes allocated statically by the callee.
-  uint64_t AllocatedSize;
-  unsigned NumInstructions, NumVectorInstructions;
-  int FiftyPercentVectorBonus, TenPercentVectorBonus;
-  int VectorBonus;
-
-  // While we walk the potentially-inlined instructions, we build up and
-  // maintain a mapping of simplified values specific to this callsite. The
-  // idea is to propagate any special information we have about arguments to
-  // this call through the inlinable section of the function, and account for
-  // likely simplifications post-inlining. The most important aspect we track
-  // is CFG altering simplifications -- when we prove a basic block dead, that
-  // can cause dramatic shifts in the cost of inlining a function.
-  DenseMap<Value *, Constant *> SimplifiedValues;
-
-  // Keep track of the values which map back (through function arguments) to
-  // allocas on the caller stack which could be simplified through SROA.
-  DenseMap<Value *, Value *> SROAArgValues;
-
-  // The mapping of caller Alloca values to their accumulated cost savings. If
-  // we have to disable SROA for one of the allocas, this tells us how much
-  // cost must be added.
-  DenseMap<Value *, int> SROAArgCosts;
-
-  // Keep track of values which map to a pointer base and constant offset.
-  DenseMap<Value *, std::pair<Value *, APInt> > ConstantOffsetPtrs;
-
-  // Custom simplification helper routines.
-  bool isAllocaDerivedArg(Value *V);
-  bool lookupSROAArgAndCost(Value *V, Value *&Arg,
-                            DenseMap<Value *, int>::iterator &CostIt);
-  void disableSROA(DenseMap<Value *, int>::iterator CostIt);
-  void disableSROA(Value *V);
-  void accumulateSROACost(DenseMap<Value *, int>::iterator CostIt,
-                          int InstructionCost);
-  bool isGEPOffsetConstant(GetElementPtrInst &GEP);
-  bool accumulateGEPOffset(GEPOperator &GEP, APInt &Offset);
-  bool simplifyCallSite(Function *F, CallSite CS);
-  ConstantInt *stripAndComputeInBoundsConstantOffsets(Value *&V);
-
-  /// Return true if the given argument to the function being considered for
-  /// inlining has the given attribute set either at the call site or the
-  /// function declaration.  Primarily used to inspect call site specific
-  /// attributes since these can be more precise than the ones on the callee
-  /// itself. 
-  bool paramHasAttr(Argument *A, Attribute::AttrKind Attr);
-  
-  /// Return true if the given value is known non null within the callee if
-  /// inlined through this particular callsite. 
-  bool isKnownNonNullInCallee(Value *V);
-
-  // Custom analysis routines.
-  bool analyzeBlock(BasicBlock *BB, SmallPtrSetImpl<const Value *> &EphValues);
-
-  // Disable several entry points to the visitor so we don't accidentally use
-  // them by declaring but not defining them here.
-  void visit(Module *);     void visit(Module &);
-  void visit(Function *);   void visit(Function &);
-  void visit(BasicBlock *); void visit(BasicBlock &);
-
-  // Provide base case for our instruction visit.
-  bool visitInstruction(Instruction &I);
-
-  // Our visit overrides.
-  bool visitAlloca(AllocaInst &I);
-  bool visitPHI(PHINode &I);
-  bool visitGetElementPtr(GetElementPtrInst &I);
-  bool visitBitCast(BitCastInst &I);
-  bool visitPtrToInt(PtrToIntInst &I);
-  bool visitIntToPtr(IntToPtrInst &I);
-  bool visitCastInst(CastInst &I);
-  bool visitUnaryInstruction(UnaryInstruction &I);
-  bool visitCmpInst(CmpInst &I);
-  bool visitSub(BinaryOperator &I);
-  bool visitBinaryOperator(BinaryOperator &I);
-  bool visitLoad(LoadInst &I);
-  bool visitStore(StoreInst &I);
-  bool visitExtractValue(ExtractValueInst &I);
-  bool visitInsertValue(InsertValueInst &I);
-  bool visitCallSite(CallSite CS);
-  bool visitReturnInst(ReturnInst &RI);
-  bool visitBranchInst(BranchInst &BI);
-  bool visitSwitchInst(SwitchInst &SI);
-  bool visitIndirectBrInst(IndirectBrInst &IBI);
-  bool visitResumeInst(ResumeInst &RI);
-  bool visitCleanupReturnInst(CleanupReturnInst &RI);
-  bool visitCatchReturnInst(CatchReturnInst &RI);
-  bool visitUnreachableInst(UnreachableInst &I);
-
-public:
-  CallAnalyzer(const TargetTransformInfo &TTI, AssumptionCacheTracker *ACT,
-               Function &Callee, int Threshold, CallSite CSArg)
-    : TTI(TTI), ACT(ACT), F(Callee), CandidateCS(CSArg), Threshold(Threshold),
-        Cost(0), IsCallerRecursive(false), IsRecursiveCall(false),
-        ExposesReturnsTwice(false), HasDynamicAlloca(false),
-        ContainsNoDuplicateCall(false), HasReturn(false), HasIndirectBr(false),
-        HasFrameEscape(false), AllocatedSize(0), NumInstructions(0),
-        NumVectorInstructions(0), FiftyPercentVectorBonus(0),
-        TenPercentVectorBonus(0), VectorBonus(0), NumConstantArgs(0),
-        NumConstantOffsetPtrArgs(0), NumAllocaArgs(0), NumConstantPtrCmps(0),
-        NumConstantPtrDiffs(0), NumInstructionsSimplified(0),
-        SROACostSavings(0), SROACostSavingsLost(0) {}
-
-  bool analyzeCall(CallSite CS);
-
-  int getThreshold() { return Threshold; }
-  int getCost() { return Cost; }
-
-  // Keep a bunch of stats about the cost savings found so we can print them
-  // out when debugging.
-  unsigned NumConstantArgs;
-  unsigned NumConstantOffsetPtrArgs;
-  unsigned NumAllocaArgs;
-  unsigned NumConstantPtrCmps;
-  unsigned NumConstantPtrDiffs;
-  unsigned NumInstructionsSimplified;
-  unsigned SROACostSavings;
-  unsigned SROACostSavingsLost;
-
-  void dump();
-};
-
-} // namespace
-
-/// \brief Test whether the given value is an Alloca-derived function argument.
-bool CallAnalyzer::isAllocaDerivedArg(Value *V) {
-  return SROAArgValues.count(V);
-}
-
-/// \brief Lookup the SROA-candidate argument and cost iterator which V maps to.
-/// Returns false if V does not map to a SROA-candidate.
-bool CallAnalyzer::lookupSROAArgAndCost(
-    Value *V, Value *&Arg, DenseMap<Value *, int>::iterator &CostIt) {
-  if (SROAArgValues.empty() || SROAArgCosts.empty())
-    return false;
-
-  DenseMap<Value *, Value *>::iterator ArgIt = SROAArgValues.find(V);
-  if (ArgIt == SROAArgValues.end())
-    return false;
-
-  Arg = ArgIt->second;
-  CostIt = SROAArgCosts.find(Arg);
-  return CostIt != SROAArgCosts.end();
-}
-
-/// \brief Disable SROA for the candidate marked by this cost iterator.
-///
-/// This marks the candidate as no longer viable for SROA, and adds the cost
-/// savings associated with it back into the inline cost measurement.
-void CallAnalyzer::disableSROA(DenseMap<Value *, int>::iterator CostIt) {
-  // If we're no longer able to perform SROA we need to undo its cost savings
-  // and prevent subsequent analysis.
-  Cost += CostIt->second;
-  SROACostSavings -= CostIt->second;
-  SROACostSavingsLost += CostIt->second;
-  SROAArgCosts.erase(CostIt);
-}
-
-/// \brief If 'V' maps to a SROA candidate, disable SROA for it.
-void CallAnalyzer::disableSROA(Value *V) {
-  Value *SROAArg;
-  DenseMap<Value *, int>::iterator CostIt;
-  if (lookupSROAArgAndCost(V, SROAArg, CostIt))
-    disableSROA(CostIt);
-}
-
-/// \brief Accumulate the given cost for a particular SROA candidate.
-void CallAnalyzer::accumulateSROACost(DenseMap<Value *, int>::iterator CostIt,
-                                      int InstructionCost) {
-  CostIt->second += InstructionCost;
-  SROACostSavings += InstructionCost;
-}
-
-/// \brief Check whether a GEP's indices are all constant.
-///
-/// Respects any simplified values known during the analysis of this callsite.
-bool CallAnalyzer::isGEPOffsetConstant(GetElementPtrInst &GEP) {
-  for (User::op_iterator I = GEP.idx_begin(), E = GEP.idx_end(); I != E; ++I)
-    if (!isa<Constant>(*I) && !SimplifiedValues.lookup(*I))
-      return false;
-
-  return true;
-}
-
-/// \brief Accumulate a constant GEP offset into an APInt if possible.
-///
-/// Returns false if unable to compute the offset for any reason. Respects any
-/// simplified values known during the analysis of this callsite.
-bool CallAnalyzer::accumulateGEPOffset(GEPOperator &GEP, APInt &Offset) {
-  const DataLayout &DL = F.getParent()->getDataLayout();
-  unsigned IntPtrWidth = DL.getPointerSizeInBits();
-  assert(IntPtrWidth == Offset.getBitWidth());
-
-  for (gep_type_iterator GTI = gep_type_begin(GEP), GTE = gep_type_end(GEP);
-       GTI != GTE; ++GTI) {
-    ConstantInt *OpC = dyn_cast<ConstantInt>(GTI.getOperand());
-    if (!OpC)
-      if (Constant *SimpleOp = SimplifiedValues.lookup(GTI.getOperand()))
-        OpC = dyn_cast<ConstantInt>(SimpleOp);
-    if (!OpC)
-      return false;
-    if (OpC->isZero()) continue;
-
-    // Handle a struct index, which adds its field offset to the pointer.
-    if (StructType *STy = dyn_cast<StructType>(*GTI)) {
-      unsigned ElementIdx = OpC->getZExtValue();
-      const StructLayout *SL = DL.getStructLayout(STy);
-      Offset += APInt(IntPtrWidth, SL->getElementOffset(ElementIdx));
-      continue;
-    }
-
-    APInt TypeSize(IntPtrWidth, DL.getTypeAllocSize(GTI.getIndexedType()));
-    Offset += OpC->getValue().sextOrTrunc(IntPtrWidth) * TypeSize;
-  }
-  return true;
-}
-
-bool CallAnalyzer::visitAlloca(AllocaInst &I) {
-  // Check whether inlining will turn a dynamic alloca into a static
-  // alloca, and handle that case.
-  if (I.isArrayAllocation()) {
-    if (Constant *Size = SimplifiedValues.lookup(I.getArraySize())) {
-      ConstantInt *AllocSize = dyn_cast<ConstantInt>(Size);
-      assert(AllocSize && "Allocation size not a constant int?");
-      Type *Ty = I.getAllocatedType();
-      AllocatedSize += Ty->getPrimitiveSizeInBits() * AllocSize->getZExtValue();
-      return Base::visitAlloca(I);
-    }
-  }
-
-  // Accumulate the allocated size.
-  if (I.isStaticAlloca()) {
-    const DataLayout &DL = F.getParent()->getDataLayout();
-    Type *Ty = I.getAllocatedType();
-    AllocatedSize += DL.getTypeAllocSize(Ty);
-  }
-
-  // We will happily inline static alloca instructions.
-  if (I.isStaticAlloca())
-    return Base::visitAlloca(I);
-
-  // FIXME: This is overly conservative. Dynamic allocas are inefficient for
-  // a variety of reasons, and so we would like to not inline them into
-  // functions which don't currently have a dynamic alloca. This simply
-  // disables inlining altogether in the presence of a dynamic alloca.
-  HasDynamicAlloca = true;
-  return false;
-}
-
-bool CallAnalyzer::visitPHI(PHINode &I) {
-  // FIXME: We should potentially be tracking values through phi nodes,
-  // especially when they collapse to a single value due to deleted CFG edges
-  // during inlining.
-
-  // FIXME: We need to propagate SROA *disabling* through phi nodes, even
-  // though we don't want to propagate it's bonuses. The idea is to disable
-  // SROA if it *might* be used in an inappropriate manner.
-
-  // Phi nodes are always zero-cost.
-  return true;
-}
-
-bool CallAnalyzer::visitGetElementPtr(GetElementPtrInst &I) {
-  Value *SROAArg;
-  DenseMap<Value *, int>::iterator CostIt;
-  bool SROACandidate = lookupSROAArgAndCost(I.getPointerOperand(),
-                                            SROAArg, CostIt);
-
-  // Try to fold GEPs of constant-offset call site argument pointers. This
-  // requires target data and inbounds GEPs.
-  if (I.isInBounds()) {
-    // Check if we have a base + offset for the pointer.
-    Value *Ptr = I.getPointerOperand();
-    std::pair<Value *, APInt> BaseAndOffset = ConstantOffsetPtrs.lookup(Ptr);
-    if (BaseAndOffset.first) {
-      // Check if the offset of this GEP is constant, and if so accumulate it
-      // into Offset.
-      if (!accumulateGEPOffset(cast<GEPOperator>(I), BaseAndOffset.second)) {
-        // Non-constant GEPs aren't folded, and disable SROA.
-        if (SROACandidate)
-          disableSROA(CostIt);
-        return false;
-      }
-
-      // Add the result as a new mapping to Base + Offset.
-      ConstantOffsetPtrs[&I] = BaseAndOffset;
-
-      // Also handle SROA candidates here, we already know that the GEP is
-      // all-constant indexed.
-      if (SROACandidate)
-        SROAArgValues[&I] = SROAArg;
-
-      return true;
-    }
-  }
-
-  if (isGEPOffsetConstant(I)) {
-    if (SROACandidate)
-      SROAArgValues[&I] = SROAArg;
-
-    // Constant GEPs are modeled as free.
-    return true;
-  }
-
-  // Variable GEPs will require math and will disable SROA.
-  if (SROACandidate)
-    disableSROA(CostIt);
-  return false;
-}
-
-bool CallAnalyzer::visitBitCast(BitCastInst &I) {
-  // Propagate constants through bitcasts.
-  Constant *COp = dyn_cast<Constant>(I.getOperand(0));
-  if (!COp)
-    COp = SimplifiedValues.lookup(I.getOperand(0));
-  if (COp)
-    if (Constant *C = ConstantExpr::getBitCast(COp, I.getType())) {
-      SimplifiedValues[&I] = C;
-      return true;
-    }
-
-  // Track base/offsets through casts
-  std::pair<Value *, APInt> BaseAndOffset
-    = ConstantOffsetPtrs.lookup(I.getOperand(0));
-  // Casts don't change the offset, just wrap it up.
-  if (BaseAndOffset.first)
-    ConstantOffsetPtrs[&I] = BaseAndOffset;
-
-  // Also look for SROA candidates here.
-  Value *SROAArg;
-  DenseMap<Value *, int>::iterator CostIt;
-  if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt))
-    SROAArgValues[&I] = SROAArg;
-
-  // Bitcasts are always zero cost.
-  return true;
-}
-
-bool CallAnalyzer::visitPtrToInt(PtrToIntInst &I) {
-  // Propagate constants through ptrtoint.
-  Constant *COp = dyn_cast<Constant>(I.getOperand(0));
-  if (!COp)
-    COp = SimplifiedValues.lookup(I.getOperand(0));
-  if (COp)
-    if (Constant *C = ConstantExpr::getPtrToInt(COp, I.getType())) {
-      SimplifiedValues[&I] = C;
-      return true;
-    }
-
-  // Track base/offset pairs when converted to a plain integer provided the
-  // integer is large enough to represent the pointer.
-  unsigned IntegerSize = I.getType()->getScalarSizeInBits();
-  const DataLayout &DL = F.getParent()->getDataLayout();
-  if (IntegerSize >= DL.getPointerSizeInBits()) {
-    std::pair<Value *, APInt> BaseAndOffset
-      = ConstantOffsetPtrs.lookup(I.getOperand(0));
-    if (BaseAndOffset.first)
-      ConstantOffsetPtrs[&I] = BaseAndOffset;
-  }
-
-  // This is really weird. Technically, ptrtoint will disable SROA. However,
-  // unless that ptrtoint is *used* somewhere in the live basic blocks after
-  // inlining, it will be nuked, and SROA should proceed. All of the uses which
-  // would block SROA would also block SROA if applied directly to a pointer,
-  // and so we can just add the integer in here. The only places where SROA is
-  // preserved either cannot fire on an integer, or won't in-and-of themselves
-  // disable SROA (ext) w/o some later use that we would see and disable.
-  Value *SROAArg;
-  DenseMap<Value *, int>::iterator CostIt;
-  if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt))
-    SROAArgValues[&I] = SROAArg;
-
-  return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I);
-}
-
-bool CallAnalyzer::visitIntToPtr(IntToPtrInst &I) {
-  // Propagate constants through ptrtoint.
-  Constant *COp = dyn_cast<Constant>(I.getOperand(0));
-  if (!COp)
-    COp = SimplifiedValues.lookup(I.getOperand(0));
-  if (COp)
-    if (Constant *C = ConstantExpr::getIntToPtr(COp, I.getType())) {
-      SimplifiedValues[&I] = C;
-      return true;
-    }
-
-  // Track base/offset pairs when round-tripped through a pointer without
-  // modifications provided the integer is not too large.
-  Value *Op = I.getOperand(0);
-  unsigned IntegerSize = Op->getType()->getScalarSizeInBits();
-  const DataLayout &DL = F.getParent()->getDataLayout();
-  if (IntegerSize <= DL.getPointerSizeInBits()) {
-    std::pair<Value *, APInt> BaseAndOffset = ConstantOffsetPtrs.lookup(Op);
-    if (BaseAndOffset.first)
-      ConstantOffsetPtrs[&I] = BaseAndOffset;
-  }
-
-  // "Propagate" SROA here in the same manner as we do for ptrtoint above.
-  Value *SROAArg;
-  DenseMap<Value *, int>::iterator CostIt;
-  if (lookupSROAArgAndCost(Op, SROAArg, CostIt))
-    SROAArgValues[&I] = SROAArg;
-
-  return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I);
-}
-
-bool CallAnalyzer::visitCastInst(CastInst &I) {
-  // Propagate constants through ptrtoint.
-  Constant *COp = dyn_cast<Constant>(I.getOperand(0));
-  if (!COp)
-    COp = SimplifiedValues.lookup(I.getOperand(0));
-  if (COp)
-    if (Constant *C = ConstantExpr::getCast(I.getOpcode(), COp, I.getType())) {
-      SimplifiedValues[&I] = C;
-      return true;
-    }
-
-  // Disable SROA in the face of arbitrary casts we don't whitelist elsewhere.
-  disableSROA(I.getOperand(0));
-
-  return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I);
-}
-
-bool CallAnalyzer::visitUnaryInstruction(UnaryInstruction &I) {
-  Value *Operand = I.getOperand(0);
-  Constant *COp = dyn_cast<Constant>(Operand);
-  if (!COp)
-    COp = SimplifiedValues.lookup(Operand);
-  if (COp) {
-    const DataLayout &DL = F.getParent()->getDataLayout();
-    if (Constant *C = ConstantFoldInstOperands(I.getOpcode(), I.getType(),
-                                               COp, DL)) {
-      SimplifiedValues[&I] = C;
-      return true;
-    }
-  }
-
-  // Disable any SROA on the argument to arbitrary unary operators.
-  disableSROA(Operand);
-
-  return false;
-}
-
-bool CallAnalyzer::paramHasAttr(Argument *A, Attribute::AttrKind Attr) {
-  unsigned ArgNo = A->getArgNo();
-  return CandidateCS.paramHasAttr(ArgNo+1, Attr);
-}
-
-bool CallAnalyzer::isKnownNonNullInCallee(Value *V) {
-  // Does the *call site* have the NonNull attribute set on an argument?  We
-  // use the attribute on the call site to memoize any analysis done in the
-  // caller. This will also trip if the callee function has a non-null
-  // parameter attribute, but that's a less interesting case because hopefully
-  // the callee would already have been simplified based on that.
-  if (Argument *A = dyn_cast<Argument>(V))
-    if (paramHasAttr(A, Attribute::NonNull))
-      return true;
-  
-  // Is this an alloca in the caller?  This is distinct from the attribute case
-  // above because attributes aren't updated within the inliner itself and we
-  // always want to catch the alloca derived case.
-  if (isAllocaDerivedArg(V))
-    // We can actually predict the result of comparisons between an
-    // alloca-derived value and null. Note that this fires regardless of
-    // SROA firing.
-    return true;
-  
-  return false;
-}
-
-bool CallAnalyzer::visitCmpInst(CmpInst &I) {
-  Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
-  // First try to handle simplified comparisons.
-  if (!isa<Constant>(LHS))
-    if (Constant *SimpleLHS = SimplifiedValues.lookup(LHS))
-      LHS = SimpleLHS;
-  if (!isa<Constant>(RHS))
-    if (Constant *SimpleRHS = SimplifiedValues.lookup(RHS))
-      RHS = SimpleRHS;
-  if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
-    if (Constant *CRHS = dyn_cast<Constant>(RHS))
-      if (Constant *C = ConstantExpr::getCompare(I.getPredicate(), CLHS, CRHS)) {
-        SimplifiedValues[&I] = C;
-        return true;
-      }
-  }
-
-  if (I.getOpcode() == Instruction::FCmp)
-    return false;
-
-  // Otherwise look for a comparison between constant offset pointers with
-  // a common base.
-  Value *LHSBase, *RHSBase;
-  APInt LHSOffset, RHSOffset;
-  std::tie(LHSBase, LHSOffset) = ConstantOffsetPtrs.lookup(LHS);
-  if (LHSBase) {
-    std::tie(RHSBase, RHSOffset) = ConstantOffsetPtrs.lookup(RHS);
-    if (RHSBase && LHSBase == RHSBase) {
-      // We have common bases, fold the icmp to a constant based on the
-      // offsets.
-      Constant *CLHS = ConstantInt::get(LHS->getContext(), LHSOffset);
-      Constant *CRHS = ConstantInt::get(RHS->getContext(), RHSOffset);
-      if (Constant *C = ConstantExpr::getICmp(I.getPredicate(), CLHS, CRHS)) {
-        SimplifiedValues[&I] = C;
-        ++NumConstantPtrCmps;
-        return true;
-      }
-    }
-  }
-
-  // If the comparison is an equality comparison with null, we can simplify it
-  // if we know the value (argument) can't be null
-  if (I.isEquality() && isa<ConstantPointerNull>(I.getOperand(1)) &&
-      isKnownNonNullInCallee(I.getOperand(0))) {
-    bool IsNotEqual = I.getPredicate() == CmpInst::ICMP_NE;
-    SimplifiedValues[&I] = IsNotEqual ? ConstantInt::getTrue(I.getType())
-                                      : ConstantInt::getFalse(I.getType());
-    return true;
-  }
-  // Finally check for SROA candidates in comparisons.
-  Value *SROAArg;
-  DenseMap<Value *, int>::iterator CostIt;
-  if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt)) {
-    if (isa<ConstantPointerNull>(I.getOperand(1))) {
-      accumulateSROACost(CostIt, InlineConstants::InstrCost);
-      return true;
-    }
-
-    disableSROA(CostIt);
-  }
-
-  return false;
-}
-
-bool CallAnalyzer::visitSub(BinaryOperator &I) {
-  // Try to handle a special case: we can fold computing the difference of two
-  // constant-related pointers.
-  Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
-  Value *LHSBase, *RHSBase;
-  APInt LHSOffset, RHSOffset;
-  std::tie(LHSBase, LHSOffset) = ConstantOffsetPtrs.lookup(LHS);
-  if (LHSBase) {
-    std::tie(RHSBase, RHSOffset) = ConstantOffsetPtrs.lookup(RHS);
-    if (RHSBase && LHSBase == RHSBase) {
-      // We have common bases, fold the subtract to a constant based on the
-      // offsets.
-      Constant *CLHS = ConstantInt::get(LHS->getContext(), LHSOffset);
-      Constant *CRHS = ConstantInt::get(RHS->getContext(), RHSOffset);
-      if (Constant *C = ConstantExpr::getSub(CLHS, CRHS)) {
-        SimplifiedValues[&I] = C;
-        ++NumConstantPtrDiffs;
-        return true;
-      }
-    }
-  }
-
-  // Otherwise, fall back to the generic logic for simplifying and handling
-  // instructions.
-  return Base::visitSub(I);
-}
-
-bool CallAnalyzer::visitBinaryOperator(BinaryOperator &I) {
-  Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
-  const DataLayout &DL = F.getParent()->getDataLayout();
-  if (!isa<Constant>(LHS))
-    if (Constant *SimpleLHS = SimplifiedValues.lookup(LHS))
-      LHS = SimpleLHS;
-  if (!isa<Constant>(RHS))
-    if (Constant *SimpleRHS = SimplifiedValues.lookup(RHS))
-      RHS = SimpleRHS;
-  Value *SimpleV = nullptr;
-  if (auto FI = dyn_cast<FPMathOperator>(&I))
-    SimpleV =
-        SimplifyFPBinOp(I.getOpcode(), LHS, RHS, FI->getFastMathFlags(), DL);
-  else
-    SimpleV = SimplifyBinOp(I.getOpcode(), LHS, RHS, DL);
-
-  if (Constant *C = dyn_cast_or_null<Constant>(SimpleV)) {
-    SimplifiedValues[&I] = C;
-    return true;
-  }
-
-  // Disable any SROA on arguments to arbitrary, unsimplified binary operators.
-  disableSROA(LHS);
-  disableSROA(RHS);
-
-  return false;
-}
-
-bool CallAnalyzer::visitLoad(LoadInst &I) {
-  Value *SROAArg;
-  DenseMap<Value *, int>::iterator CostIt;
-  if (lookupSROAArgAndCost(I.getPointerOperand(), SROAArg, CostIt)) {
-    if (I.isSimple()) {
-      accumulateSROACost(CostIt, InlineConstants::InstrCost);
-      return true;
-    }
-
-    disableSROA(CostIt);
-  }
-
-  return false;
-}
-
-bool CallAnalyzer::visitStore(StoreInst &I) {
-  Value *SROAArg;
-  DenseMap<Value *, int>::iterator CostIt;
-  if (lookupSROAArgAndCost(I.getPointerOperand(), SROAArg, CostIt)) {
-    if (I.isSimple()) {
-      accumulateSROACost(CostIt, InlineConstants::InstrCost);
-      return true;
-    }
-
-    disableSROA(CostIt);
-  }
-
-  return false;
-}
-
-bool CallAnalyzer::visitExtractValue(ExtractValueInst &I) {
-  // Constant folding for extract value is trivial.
-  Constant *C = dyn_cast<Constant>(I.getAggregateOperand());
-  if (!C)
-    C = SimplifiedValues.lookup(I.getAggregateOperand());
-  if (C) {
-    SimplifiedValues[&I] = ConstantExpr::getExtractValue(C, I.getIndices());
-    return true;
-  }
-
-  // SROA can look through these but give them a cost.
-  return false;
-}
-
-bool CallAnalyzer::visitInsertValue(InsertValueInst &I) {
-  // Constant folding for insert value is trivial.
-  Constant *AggC = dyn_cast<Constant>(I.getAggregateOperand());
-  if (!AggC)
-    AggC = SimplifiedValues.lookup(I.getAggregateOperand());
-  Constant *InsertedC = dyn_cast<Constant>(I.getInsertedValueOperand());
-  if (!InsertedC)
-    InsertedC = SimplifiedValues.lookup(I.getInsertedValueOperand());
-  if (AggC && InsertedC) {
-    SimplifiedValues[&I] = ConstantExpr::getInsertValue(AggC, InsertedC,
-                                                        I.getIndices());
-    return true;
-  }
-
-  // SROA can look through these but give them a cost.
-  return false;
-}
-
-/// \brief Try to simplify a call site.
-///
-/// Takes a concrete function and callsite and tries to actually simplify it by
-/// analyzing the arguments and call itself with instsimplify. Returns true if
-/// it has simplified the callsite to some other entity (a constant), making it
-/// free.
-bool CallAnalyzer::simplifyCallSite(Function *F, CallSite CS) {
-  // FIXME: Using the instsimplify logic directly for this is inefficient
-  // because we have to continually rebuild the argument list even when no
-  // simplifications can be performed. Until that is fixed with remapping
-  // inside of instsimplify, directly constant fold calls here.
-  if (!canConstantFoldCallTo(F))
-    return false;
-
-  // Try to re-map the arguments to constants.
-  SmallVector<Constant *, 4> ConstantArgs;
-  ConstantArgs.reserve(CS.arg_size());
-  for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
-       I != E; ++I) {
-    Constant *C = dyn_cast<Constant>(*I);
-    if (!C)
-      C = dyn_cast_or_null<Constant>(SimplifiedValues.lookup(*I));
-    if (!C)
-      return false; // This argument doesn't map to a constant.
-
-    ConstantArgs.push_back(C);
-  }
-  if (Constant *C = ConstantFoldCall(F, ConstantArgs)) {
-    SimplifiedValues[CS.getInstruction()] = C;
-    return true;
-  }
-
-  return false;
-}
-
-bool CallAnalyzer::visitCallSite(CallSite CS) {
-  if (CS.hasFnAttr(Attribute::ReturnsTwice) &&
-      !F.hasFnAttribute(Attribute::ReturnsTwice)) {
-    // This aborts the entire analysis.
-    ExposesReturnsTwice = true;
-    return false;
-  }
-  if (CS.isCall() &&
-      cast<CallInst>(CS.getInstruction())->cannotDuplicate())
-    ContainsNoDuplicateCall = true;
-
-  if (Function *F = CS.getCalledFunction()) {
-    // When we have a concrete function, first try to simplify it directly.
-    if (simplifyCallSite(F, CS))
-      return true;
-
-    // Next check if it is an intrinsic we know about.
-    // FIXME: Lift this into part of the InstVisitor.
-    if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(CS.getInstruction())) {
-      switch (II->getIntrinsicID()) {
-      default:
-        return Base::visitCallSite(CS);
-
-      case Intrinsic::memset:
-      case Intrinsic::memcpy:
-      case Intrinsic::memmove:
-        // SROA can usually chew through these intrinsics, but they aren't free.
-        return false;
-      case Intrinsic::localescape:
-        HasFrameEscape = true;
-        return false;
-      }
-    }
-
-    if (F == CS.getInstruction()->getParent()->getParent()) {
-      // This flag will fully abort the analysis, so don't bother with anything
-      // else.
-      IsRecursiveCall = true;
-      return false;
-    }
-
-    if (TTI.isLoweredToCall(F)) {
-      // We account for the average 1 instruction per call argument setup
-      // here.
-      Cost += CS.arg_size() * InlineConstants::InstrCost;
-
-      // Everything other than inline ASM will also have a significant cost
-      // merely from making the call.
-      if (!isa<InlineAsm>(CS.getCalledValue()))
-        Cost += InlineConstants::CallPenalty;
-    }
-
-    return Base::visitCallSite(CS);
-  }
-
-  // Otherwise we're in a very special case -- an indirect function call. See
-  // if we can be particularly clever about this.
-  Value *Callee = CS.getCalledValue();
-
-  // First, pay the price of the argument setup. We account for the average
-  // 1 instruction per call argument setup here.
-  Cost += CS.arg_size() * InlineConstants::InstrCost;
-
-  // Next, check if this happens to be an indirect function call to a known
-  // function in this inline context. If not, we've done all we can.
-  Function *F = dyn_cast_or_null<Function>(SimplifiedValues.lookup(Callee));
-  if (!F)
-    return Base::visitCallSite(CS);
-
-  // If we have a constant that we are calling as a function, we can peer
-  // through it and see the function target. This happens not infrequently
-  // during devirtualization and so we want to give it a hefty bonus for
-  // inlining, but cap that bonus in the event that inlining wouldn't pan
-  // out. Pretend to inline the function, with a custom threshold.
-  CallAnalyzer CA(TTI, ACT, *F, InlineConstants::IndirectCallThreshold, CS);
-  if (CA.analyzeCall(CS)) {
-    // We were able to inline the indirect call! Subtract the cost from the
-    // bonus we want to apply, but don't go below zero.
-    Cost -= std::max(0, InlineConstants::IndirectCallThreshold - CA.getCost());
-  }
-
-  return Base::visitCallSite(CS);
-}
-
-bool CallAnalyzer::visitReturnInst(ReturnInst &RI) {
-  // At least one return instruction will be free after inlining.
-  bool Free = !HasReturn;
-  HasReturn = true;
-  return Free;
-}
-
-bool CallAnalyzer::visitBranchInst(BranchInst &BI) {
-  // We model unconditional branches as essentially free -- they really
-  // shouldn't exist at all, but handling them makes the behavior of the
-  // inliner more regular and predictable. Interestingly, conditional branches
-  // which will fold away are also free.
-  return BI.isUnconditional() || isa<ConstantInt>(BI.getCondition()) ||
-         dyn_cast_or_null<ConstantInt>(
-             SimplifiedValues.lookup(BI.getCondition()));
-}
-
-bool CallAnalyzer::visitSwitchInst(SwitchInst &SI) {
-  // We model unconditional switches as free, see the comments on handling
-  // branches.
-  if (isa<ConstantInt>(SI.getCondition()))
-    return true;
-  if (Value *V = SimplifiedValues.lookup(SI.getCondition()))
-    if (isa<ConstantInt>(V))
-      return true;
-
-  // Otherwise, we need to accumulate a cost proportional to the number of
-  // distinct successor blocks. This fan-out in the CFG cannot be represented
-  // for free even if we can represent the core switch as a jumptable that
-  // takes a single instruction.
-  //
-  // NB: We convert large switches which are just used to initialize large phi
-  // nodes to lookup tables instead in simplify-cfg, so this shouldn't prevent
-  // inlining those. It will prevent inlining in cases where the optimization
-  // does not (yet) fire.
-  SmallPtrSet<BasicBlock *, 8> SuccessorBlocks;
-  SuccessorBlocks.insert(SI.getDefaultDest());
-  for (auto I = SI.case_begin(), E = SI.case_end(); I != E; ++I)
-    SuccessorBlocks.insert(I.getCaseSuccessor());
-  // Add cost corresponding to the number of distinct destinations. The first
-  // we model as free because of fallthrough.
-  Cost += (SuccessorBlocks.size() - 1) * InlineConstants::InstrCost;
-  return false;
-}
-
-bool CallAnalyzer::visitIndirectBrInst(IndirectBrInst &IBI) {
-  // We never want to inline functions that contain an indirectbr.  This is
-  // incorrect because all the blockaddress's (in static global initializers
-  // for example) would be referring to the original function, and this
-  // indirect jump would jump from the inlined copy of the function into the
-  // original function which is extremely undefined behavior.
-  // FIXME: This logic isn't really right; we can safely inline functions with
-  // indirectbr's as long as no other function or global references the
-  // blockaddress of a block within the current function.
-  HasIndirectBr = true;
-  return false;
-}
-
-bool CallAnalyzer::visitResumeInst(ResumeInst &RI) {
-  // FIXME: It's not clear that a single instruction is an accurate model for
-  // the inline cost of a resume instruction.
-  return false;
-}
-
-bool CallAnalyzer::visitCleanupReturnInst(CleanupReturnInst &CRI) {
-  // FIXME: It's not clear that a single instruction is an accurate model for
-  // the inline cost of a cleanupret instruction.
-  return false;
-}
-
-bool CallAnalyzer::visitCatchReturnInst(CatchReturnInst &CRI) {
-  // FIXME: It's not clear that a single instruction is an accurate model for
-  // the inline cost of a cleanupret instruction.
-  return false;
-}
-
-bool CallAnalyzer::visitUnreachableInst(UnreachableInst &I) {
-  // FIXME: It might be reasonably to discount the cost of instructions leading
-  // to unreachable as they have the lowest possible impact on both runtime and
-  // code size.
-  return true; // No actual code is needed for unreachable.
-}
-
-bool CallAnalyzer::visitInstruction(Instruction &I) {
-  // Some instructions are free. All of the free intrinsics can also be
-  // handled by SROA, etc.
-  if (TargetTransformInfo::TCC_Free == TTI.getUserCost(&I))
-    return true;
-
-  // We found something we don't understand or can't handle. Mark any SROA-able
-  // values in the operand list as no longer viable.
-  for (User::op_iterator OI = I.op_begin(), OE = I.op_end(); OI != OE; ++OI)
-    disableSROA(*OI);
-
-  return false;
-}
-
-
-/// \brief Analyze a basic block for its contribution to the inline cost.
-///
-/// This method walks the analyzer over every instruction in the given basic
-/// block and accounts for their cost during inlining at this callsite. It
-/// aborts early if the threshold has been exceeded or an impossible to inline
-/// construct has been detected. It returns false if inlining is no longer
-/// viable, and true if inlining remains viable.
-bool CallAnalyzer::analyzeBlock(BasicBlock *BB,
-                                SmallPtrSetImpl<const Value *> &EphValues) {
-  for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
-    // FIXME: Currently, the number of instructions in a function regardless of
-    // our ability to simplify them during inline to constants or dead code,
-    // are actually used by the vector bonus heuristic. As long as that's true,
-    // we have to special case debug intrinsics here to prevent differences in
-    // inlining due to debug symbols. Eventually, the number of unsimplified
-    // instructions shouldn't factor into the cost computation, but until then,
-    // hack around it here.
-    if (isa<DbgInfoIntrinsic>(I))
-      continue;
-
-    // Skip ephemeral values.
-    if (EphValues.count(I))
-      continue;
-
-    ++NumInstructions;
-    if (isa<ExtractElementInst>(I) || I->getType()->isVectorTy())
-      ++NumVectorInstructions;
-
-    // If the instruction is floating point, and the target says this operation is
-    // expensive or the function has the "use-soft-float" attribute, this may
-    // eventually become a library call.  Treat the cost as such.
-    if (I->getType()->isFloatingPointTy()) {
-      bool hasSoftFloatAttr = false;
-
-      // If the function has the "use-soft-float" attribute, mark it as expensive.
-      if (F.hasFnAttribute("use-soft-float")) {
-        Attribute Attr = F.getFnAttribute("use-soft-float");
-        StringRef Val = Attr.getValueAsString();
-        if (Val == "true")
-          hasSoftFloatAttr = true;
-      }
-
-      if (TTI.getFPOpCost(I->getType()) == TargetTransformInfo::TCC_Expensive ||
-          hasSoftFloatAttr)
-        Cost += InlineConstants::CallPenalty;
-    }
-
-    // If the instruction simplified to a constant, there is no cost to this
-    // instruction. Visit the instructions using our InstVisitor to account for
-    // all of the per-instruction logic. The visit tree returns true if we
-    // consumed the instruction in any way, and false if the instruction's base
-    // cost should count against inlining.
-    if (Base::visit(I))
-      ++NumInstructionsSimplified;
-    else
-      Cost += InlineConstants::InstrCost;
-
-    // If the visit this instruction detected an uninlinable pattern, abort.
-    if (IsRecursiveCall || ExposesReturnsTwice || HasDynamicAlloca ||
-        HasIndirectBr || HasFrameEscape)
-      return false;
-
-    // If the caller is a recursive function then we don't want to inline
-    // functions which allocate a lot of stack space because it would increase
-    // the caller stack usage dramatically.
-    if (IsCallerRecursive &&
-        AllocatedSize > InlineConstants::TotalAllocaSizeRecursiveCaller)
-      return false;
-
-    // Check if we've past the maximum possible threshold so we don't spin in
-    // huge basic blocks that will never inline.
-    if (Cost > Threshold)
-      return false;
-  }
-
-  return true;
-}
-
-/// \brief Compute the base pointer and cumulative constant offsets for V.
-///
-/// This strips all constant offsets off of V, leaving it the base pointer, and
-/// accumulates the total constant offset applied in the returned constant. It
-/// returns 0 if V is not a pointer, and returns the constant '0' if there are
-/// no constant offsets applied.
-ConstantInt *CallAnalyzer::stripAndComputeInBoundsConstantOffsets(Value *&V) {
-  if (!V->getType()->isPointerTy())
-    return nullptr;
-
-  const DataLayout &DL = F.getParent()->getDataLayout();
-  unsigned IntPtrWidth = DL.getPointerSizeInBits();
-  APInt Offset = APInt::getNullValue(IntPtrWidth);
-
-  // Even though we don't look through PHI nodes, we could be called on an
-  // instruction in an unreachable block, which may be on a cycle.
-  SmallPtrSet<Value *, 4> Visited;
-  Visited.insert(V);
-  do {
-    if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
-      if (!GEP->isInBounds() || !accumulateGEPOffset(*GEP, Offset))
-        return nullptr;
-      V = GEP->getPointerOperand();
-    } else if (Operator::getOpcode(V) == Instruction::BitCast) {
-      V = cast<Operator>(V)->getOperand(0);
-    } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) {
-      if (GA->mayBeOverridden())
-        break;
-      V = GA->getAliasee();
-    } else {
-      break;
-    }
-    assert(V->getType()->isPointerTy() && "Unexpected operand type!");
-  } while (Visited.insert(V).second);
-
-  Type *IntPtrTy = DL.getIntPtrType(V->getContext());
-  return cast<ConstantInt>(ConstantInt::get(IntPtrTy, Offset));
-}
-
-/// \brief Analyze a call site for potential inlining.
-///
-/// Returns true if inlining this call is viable, and false if it is not
-/// viable. It computes the cost and adjusts the threshold based on numerous
-/// factors and heuristics. If this method returns false but the computed cost
-/// is below the computed threshold, then inlining was forcibly disabled by
-/// some artifact of the routine.
-bool CallAnalyzer::analyzeCall(CallSite CS) {
-  ++NumCallsAnalyzed;
-
-  // Perform some tweaks to the cost and threshold based on the direct
-  // callsite information.
-
-  // We want to more aggressively inline vector-dense kernels, so up the
-  // threshold, and we'll lower it if the % of vector instructions gets too
-  // low. Note that these bonuses are some what arbitrary and evolved over time
-  // by accident as much as because they are principled bonuses.
-  //
-  // FIXME: It would be nice to remove all such bonuses. At least it would be
-  // nice to base the bonus values on something more scientific.
-  assert(NumInstructions == 0);
-  assert(NumVectorInstructions == 0);
-  FiftyPercentVectorBonus = 3 * Threshold / 2;
-  TenPercentVectorBonus = 3 * Threshold / 4;
-  const DataLayout &DL = F.getParent()->getDataLayout();
-
-  // Track whether the post-inlining function would have more than one basic
-  // block. A single basic block is often intended for inlining. Balloon the
-  // threshold by 50% until we pass the single-BB phase.
-  bool SingleBB = true;
-  int SingleBBBonus = Threshold / 2;
-
-  // Speculatively apply all possible bonuses to Threshold. If cost exceeds
-  // this Threshold any time, and cost cannot decrease, we can stop processing
-  // the rest of the function body.
-  Threshold += (SingleBBBonus + FiftyPercentVectorBonus);
-
-  // Give out bonuses per argument, as the instructions setting them up will
-  // be gone after inlining.
-  for (unsigned I = 0, E = CS.arg_size(); I != E; ++I) {
-    if (CS.isByValArgument(I)) {
-      // We approximate the number of loads and stores needed by dividing the
-      // size of the byval type by the target's pointer size.
-      PointerType *PTy = cast<PointerType>(CS.getArgument(I)->getType());
-      unsigned TypeSize = DL.getTypeSizeInBits(PTy->getElementType());
-      unsigned PointerSize = DL.getPointerSizeInBits();
-      // Ceiling division.
-      unsigned NumStores = (TypeSize + PointerSize - 1) / PointerSize;
-
-      // If it generates more than 8 stores it is likely to be expanded as an
-      // inline memcpy so we take that as an upper bound. Otherwise we assume
-      // one load and one store per word copied.
-      // FIXME: The maxStoresPerMemcpy setting from the target should be used
-      // here instead of a magic number of 8, but it's not available via
-      // DataLayout.
-      NumStores = std::min(NumStores, 8U);
-
-      Cost -= 2 * NumStores * InlineConstants::InstrCost;
-    } else {
-      // For non-byval arguments subtract off one instruction per call
-      // argument.
-      Cost -= InlineConstants::InstrCost;
-    }
-  }
-
-  // If there is only one call of the function, and it has internal linkage,
-  // the cost of inlining it drops dramatically.
-  bool OnlyOneCallAndLocalLinkage = F.hasLocalLinkage() && F.hasOneUse() &&
-    &F == CS.getCalledFunction();
-  if (OnlyOneCallAndLocalLinkage)
-    Cost += InlineConstants::LastCallToStaticBonus;
-
-  // If the instruction after the call, or if the normal destination of the
-  // invoke is an unreachable instruction, the function is noreturn. As such,
-  // there is little point in inlining this unless there is literally zero
-  // cost.
-  Instruction *Instr = CS.getInstruction();
-  if (InvokeInst *II = dyn_cast<InvokeInst>(Instr)) {
-    if (isa<UnreachableInst>(II->getNormalDest()->begin()))
-      Threshold = 0;
-  } else if (isa<UnreachableInst>(++BasicBlock::iterator(Instr)))
-    Threshold = 0;
-
-  // If this function uses the coldcc calling convention, prefer not to inline
-  // it.
-  if (F.getCallingConv() == CallingConv::Cold)
-    Cost += InlineConstants::ColdccPenalty;
-
-  // Check if we're done. This can happen due to bonuses and penalties.
-  if (Cost > Threshold)
-    return false;
-
-  if (F.empty())
-    return true;
-
-  Function *Caller = CS.getInstruction()->getParent()->getParent();
-  // Check if the caller function is recursive itself.
-  for (User *U : Caller->users()) {
-    CallSite Site(U);
-    if (!Site)
-      continue;
-    Instruction *I = Site.getInstruction();
-    if (I->getParent()->getParent() == Caller) {
-      IsCallerRecursive = true;
-      break;
-    }
-  }
-
-  // Populate our simplified values by mapping from function arguments to call
-  // arguments with known important simplifications.
-  CallSite::arg_iterator CAI = CS.arg_begin();
-  for (Function::arg_iterator FAI = F.arg_begin(), FAE = F.arg_end();
-       FAI != FAE; ++FAI, ++CAI) {
-    assert(CAI != CS.arg_end());
-    if (Constant *C = dyn_cast<Constant>(CAI))
-      SimplifiedValues[FAI] = C;
-
-    Value *PtrArg = *CAI;
-    if (ConstantInt *C = stripAndComputeInBoundsConstantOffsets(PtrArg)) {
-      ConstantOffsetPtrs[FAI] = std::make_pair(PtrArg, C->getValue());
-
-      // We can SROA any pointer arguments derived from alloca instructions.
-      if (isa<AllocaInst>(PtrArg)) {
-        SROAArgValues[FAI] = PtrArg;
-        SROAArgCosts[PtrArg] = 0;
-      }
-    }
-  }
-  NumConstantArgs = SimplifiedValues.size();
-  NumConstantOffsetPtrArgs = ConstantOffsetPtrs.size();
-  NumAllocaArgs = SROAArgValues.size();
-
-  // FIXME: If a caller has multiple calls to a callee, we end up recomputing
-  // the ephemeral values multiple times (and they're completely determined by
-  // the callee, so this is purely duplicate work).
-  SmallPtrSet<const Value *, 32> EphValues;
-  CodeMetrics::collectEphemeralValues(&F, &ACT->getAssumptionCache(F), EphValues);
-
-  // The worklist of live basic blocks in the callee *after* inlining. We avoid
-  // adding basic blocks of the callee which can be proven to be dead for this
-  // particular call site in order to get more accurate cost estimates. This
-  // requires a somewhat heavyweight iteration pattern: we need to walk the
-  // basic blocks in a breadth-first order as we insert live successors. To
-  // accomplish this, prioritizing for small iterations because we exit after
-  // crossing our threshold, we use a small-size optimized SetVector.
-  typedef SetVector<BasicBlock *, SmallVector<BasicBlock *, 16>,
-                                  SmallPtrSet<BasicBlock *, 16> > BBSetVector;
-  BBSetVector BBWorklist;
-  BBWorklist.insert(&F.getEntryBlock());
-  // Note that we *must not* cache the size, this loop grows the worklist.
-  for (unsigned Idx = 0; Idx != BBWorklist.size(); ++Idx) {
-    // Bail out the moment we cross the threshold. This means we'll under-count
-    // the cost, but only when undercounting doesn't matter.
-    if (Cost > Threshold)
-      break;
-
-    BasicBlock *BB = BBWorklist[Idx];
-    if (BB->empty())
-      continue;
-
-    // Disallow inlining a blockaddress. A blockaddress only has defined
-    // behavior for an indirect branch in the same function, and we do not
-    // currently support inlining indirect branches. But, the inliner may not
-    // see an indirect branch that ends up being dead code at a particular call
-    // site. If the blockaddress escapes the function, e.g., via a global
-    // variable, inlining may lead to an invalid cross-function reference.
-    if (BB->hasAddressTaken())
-      return false;
-
-    // Analyze the cost of this block. If we blow through the threshold, this
-    // returns false, and we can bail on out.
-    if (!analyzeBlock(BB, EphValues)) {
-      if (IsRecursiveCall || ExposesReturnsTwice || HasDynamicAlloca ||
-          HasIndirectBr || HasFrameEscape)
-        return false;
-
-      // If the caller is a recursive function then we don't want to inline
-      // functions which allocate a lot of stack space because it would increase
-      // the caller stack usage dramatically.
-      if (IsCallerRecursive &&
-          AllocatedSize > InlineConstants::TotalAllocaSizeRecursiveCaller)
-        return false;
-
-      break;
-    }
-
-    TerminatorInst *TI = BB->getTerminator();
-
-    // Add in the live successors by first checking whether we have terminator
-    // that may be simplified based on the values simplified by this call.
-    if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
-      if (BI->isConditional()) {
-        Value *Cond = BI->getCondition();
-        if (ConstantInt *SimpleCond
-              = dyn_cast_or_null<ConstantInt>(SimplifiedValues.lookup(Cond))) {
-          BBWorklist.insert(BI->getSuccessor(SimpleCond->isZero() ? 1 : 0));
-          continue;
-        }
-      }
-    } else if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) {
-      Value *Cond = SI->getCondition();
-      if (ConstantInt *SimpleCond
-            = dyn_cast_or_null<ConstantInt>(SimplifiedValues.lookup(Cond))) {
-        BBWorklist.insert(SI->findCaseValue(SimpleCond).getCaseSuccessor());
-        continue;
-      }
-    }
-
-    // If we're unable to select a particular successor, just count all of
-    // them.
-    for (unsigned TIdx = 0, TSize = TI->getNumSuccessors(); TIdx != TSize;
-         ++TIdx)
-      BBWorklist.insert(TI->getSuccessor(TIdx));
-
-    // If we had any successors at this point, than post-inlining is likely to
-    // have them as well. Note that we assume any basic blocks which existed
-    // due to branches or switches which folded above will also fold after
-    // inlining.
-    if (SingleBB && TI->getNumSuccessors() > 1) {
-      // Take off the bonus we applied to the threshold.
-      Threshold -= SingleBBBonus;
-      SingleBB = false;
-    }
-  }
-
-  // If this is a noduplicate call, we can still inline as long as
-  // inlining this would cause the removal of the caller (so the instruction
-  // is not actually duplicated, just moved).
-  if (!OnlyOneCallAndLocalLinkage && ContainsNoDuplicateCall)
-    return false;
-
-  // We applied the maximum possible vector bonus at the beginning. Now,
-  // subtract the excess bonus, if any, from the Threshold before
-  // comparing against Cost.
-  if (NumVectorInstructions <= NumInstructions / 10)
-    Threshold -= FiftyPercentVectorBonus;
-  else if (NumVectorInstructions <= NumInstructions / 2)
-    Threshold -= (FiftyPercentVectorBonus - TenPercentVectorBonus);
-
-  return Cost < Threshold;
-}
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-/// \brief Dump stats about this call's analysis.
-void CallAnalyzer::dump() {
-#define DEBUG_PRINT_STAT(x) dbgs() << "      " #x ": " << x << "\n"
-  DEBUG_PRINT_STAT(NumConstantArgs);
-  DEBUG_PRINT_STAT(NumConstantOffsetPtrArgs);
-  DEBUG_PRINT_STAT(NumAllocaArgs);
-  DEBUG_PRINT_STAT(NumConstantPtrCmps);
-  DEBUG_PRINT_STAT(NumConstantPtrDiffs);
-  DEBUG_PRINT_STAT(NumInstructionsSimplified);
-  DEBUG_PRINT_STAT(NumInstructions);
-  DEBUG_PRINT_STAT(SROACostSavings);
-  DEBUG_PRINT_STAT(SROACostSavingsLost);
-  DEBUG_PRINT_STAT(ContainsNoDuplicateCall);
-  DEBUG_PRINT_STAT(Cost);
-  DEBUG_PRINT_STAT(Threshold);
-#undef DEBUG_PRINT_STAT
-}
-#endif
-
-INITIALIZE_PASS_BEGIN(InlineCostAnalysis, "inline-cost", "Inline Cost Analysis",
-                      true, true)
-INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
-INITIALIZE_PASS_END(InlineCostAnalysis, "inline-cost", "Inline Cost Analysis",
-                    true, true)
-
-char InlineCostAnalysis::ID = 0;
-
-InlineCostAnalysis::InlineCostAnalysis() : CallGraphSCCPass(ID) {}
-
-InlineCostAnalysis::~InlineCostAnalysis() {}
-
-void InlineCostAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
-  AU.setPreservesAll();
-  AU.addRequired<AssumptionCacheTracker>();
-  AU.addRequired<TargetTransformInfoWrapperPass>();
-  CallGraphSCCPass::getAnalysisUsage(AU);
-}
-
-bool InlineCostAnalysis::runOnSCC(CallGraphSCC &SCC) {
-  TTIWP = &getAnalysis<TargetTransformInfoWrapperPass>();
-  ACT = &getAnalysis<AssumptionCacheTracker>();
-  return false;
-}
-
-InlineCost InlineCostAnalysis::getInlineCost(CallSite CS, int Threshold) {
-  return getInlineCost(CS, CS.getCalledFunction(), Threshold);
-}
-
-/// \brief Test that two functions either have or have not the given attribute
-///        at the same time.
-template<typename AttrKind>
-static bool attributeMatches(Function *F1, Function *F2, AttrKind Attr) {
-  return F1->getFnAttribute(Attr) == F2->getFnAttribute(Attr);
-}
-
-/// \brief Test that there are no attribute conflicts between Caller and Callee
-///        that prevent inlining.
-static bool functionsHaveCompatibleAttributes(Function *Caller,
-                                              Function *Callee,
-                                              TargetTransformInfo &TTI) {
-  return TTI.areInlineCompatible(Caller, Callee) &&
-         attributeMatches(Caller, Callee, Attribute::SanitizeAddress) &&
-         attributeMatches(Caller, Callee, Attribute::SanitizeMemory) &&
-         attributeMatches(Caller, Callee, Attribute::SanitizeThread);
-}
-
-InlineCost InlineCostAnalysis::getInlineCost(CallSite CS, Function *Callee,
-                                             int Threshold) {
-  // Cannot inline indirect calls.
-  if (!Callee)
-    return llvm::InlineCost::getNever();
-
-  // Calls to functions with always-inline attributes should be inlined
-  // whenever possible.
-  if (CS.hasFnAttr(Attribute::AlwaysInline)) {
-    if (isInlineViable(*Callee))
-      return llvm::InlineCost::getAlways();
-    return llvm::InlineCost::getNever();
-  }
-
-  // Never inline functions with conflicting attributes (unless callee has
-  // always-inline attribute).
-  if (!functionsHaveCompatibleAttributes(CS.getCaller(), Callee,
-                                         TTIWP->getTTI(*Callee)))
-    return llvm::InlineCost::getNever();
-
-  // Don't inline this call if the caller has the optnone attribute.
-  if (CS.getCaller()->hasFnAttribute(Attribute::OptimizeNone))
-    return llvm::InlineCost::getNever();
-
-  // Don't inline functions which can be redefined at link-time to mean
-  // something else.  Don't inline functions marked noinline or call sites
-  // marked noinline.
-  if (Callee->mayBeOverridden() ||
-      Callee->hasFnAttribute(Attribute::NoInline) || CS.isNoInline())
-    return llvm::InlineCost::getNever();
-
-  DEBUG(llvm::dbgs() << "      Analyzing call of " << Callee->getName()
-        << "...\n");
-
-  CallAnalyzer CA(TTIWP->getTTI(*Callee), ACT, *Callee, Threshold, CS);
-  bool ShouldInline = CA.analyzeCall(CS);
-
-  DEBUG(CA.dump());
-
-  // Check if there was a reason to force inlining or no inlining.
-  if (!ShouldInline && CA.getCost() < CA.getThreshold())
-    return InlineCost::getNever();
-  if (ShouldInline && CA.getCost() >= CA.getThreshold())
-    return InlineCost::getAlways();
-
-  return llvm::InlineCost::get(CA.getCost(), CA.getThreshold());
-}
-
-bool InlineCostAnalysis::isInlineViable(Function &F) {
-  bool ReturnsTwice = F.hasFnAttribute(Attribute::ReturnsTwice);
-  for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE; ++BI) {
-    // Disallow inlining of functions which contain indirect branches or
-    // blockaddresses.
-    if (isa<IndirectBrInst>(BI->getTerminator()) || BI->hasAddressTaken())
-      return false;
-
-    for (BasicBlock::iterator II = BI->begin(), IE = BI->end(); II != IE;
-         ++II) {
-      CallSite CS(II);
-      if (!CS)
-        continue;
-
-      // Disallow recursive calls.
-      if (&F == CS.getCalledFunction())
-        return false;
-
-      // Disallow calls which expose returns-twice to a function not previously
-      // attributed as such.
-      if (!ReturnsTwice && CS.isCall() &&
-          cast<CallInst>(CS.getInstruction())->canReturnTwice())
-        return false;
-
-      // Disallow inlining functions that call @llvm.localescape. Doing this
-      // correctly would require major changes to the inliner.
-      if (CS.getCalledFunction() &&
-          CS.getCalledFunction()->getIntrinsicID() ==
-              llvm::Intrinsic::localescape)
-        return false;
-    }
-  }
-
-  return true;
-}

llvm/trunk/lib/Analysis/IPA/LLVMBuild.txt

-;===- ./lib/Analysis/IPA/LLVMBuild.txt -------------------------*- Conf -*--===;
-;
-;                     The LLVM Compiler Infrastructure
-;
-; This file is distributed under the University of Illinois Open Source
-; License. See LICENSE.TXT for details.
-;
-;===------------------------------------------------------------------------===;
-;
-; This is an LLVMBuild description file for the components in this subdirectory.
-;
-; For more information on the LLVMBuild system, please see:
-;
-;   http://llvm.org/docs/LLVMBuild.html
-;
-;===------------------------------------------------------------------------===;
-
-[component_0]
-type = Library
-name = IPA
-parent = Libraries
-library_name = ipa
-required_libraries = Analysis Core Support

llvm/trunk/lib/Analysis/IPA/Makefile

-##===- lib/Analysis/IPA/Makefile ---------------------------*- Makefile -*-===##
-#
-#                     The LLVM Compiler Infrastructure
-#
-# This file is distributed under the University of Illinois Open Source
-# License. See LICENSE.TXT for details.
-#
-##===----------------------------------------------------------------------===##
-
-LEVEL = ../../..
-LIBRARYNAME = LLVMipa
-BUILD_ARCHIVE = 1
-
-include $(LEVEL)/Makefile.common
-

llvm/trunk/lib/Analysis/InlineCost.cpp

+//===- InlineCost.cpp - Cost analysis for inliner -------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements inline cost analysis.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/InlineCost.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/AssumptionCache.h"
+#include "llvm/Analysis/CodeMetrics.h"
+#include "llvm/Analysis/ConstantFolding.h"
+#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/IR/CallSite.h"
+#include "llvm/IR/CallingConv.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/GetElementPtrTypeIterator.h"
+#include "llvm/IR/GlobalAlias.h"
+#include "llvm/IR/InstVisitor.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Operator.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "inline-cost"
+
+STATISTIC(NumCallsAnalyzed, "Number of call sites analyzed");
+
+namespace {
+
+class CallAnalyzer : public InstVisitor<CallAnalyzer, bool> {
+  typedef InstVisitor<CallAnalyzer, bool> Base;
+  friend class InstVisitor<CallAnalyzer, bool>;
+
+  /// The TargetTransformInfo available for this compilation.
+  const TargetTransformInfo &TTI;
+
+  /// The cache of @llvm.assume intrinsics.
+  AssumptionCacheTracker *ACT;
+
+  // The called function.
+  Function &F;
+
+  // The candidate callsite being analyzed. Please do not use this to do
+  // analysis in the caller function; we want the inline cost query to be
+  // easily cacheable. Instead, use the cover function paramHasAttr.
+  CallSite CandidateCS;
+
+  int Threshold;
+  int Cost;
+
+  bool IsCallerRecursive;
+  bool IsRecursiveCall;
+  bool ExposesReturnsTwice;
+  bool HasDynamicAlloca;
+  bool ContainsNoDuplicateCall;
+  bool HasReturn;
+  bool HasIndirectBr;
+  bool HasFrameEscape;
+
+  /// Number of bytes allocated statically by the callee.
+  uint64_t AllocatedSize;
+  unsigned NumInstructions, NumVectorInstructions;
+  int FiftyPercentVectorBonus, TenPercentVectorBonus;
+  int VectorBonus;
+
+  // While we walk the potentially-inlined instructions, we build up and
+  // maintain a mapping of simplified values specific to this callsite. The
+  // idea is to propagate any special information we have about arguments to
+  // this call through the inlinable section of the function, and account for
+  // likely simplifications post-inlining. The most important aspect we track
+  // is CFG altering simplifications -- when we prove a basic block dead, that
+  // can cause dramatic shifts in the cost of inlining a function.
+  DenseMap<Value *, Constant *> SimplifiedValues;
+
+  // Keep track of the values which map back (through function arguments) to
+  // allocas on the caller stack which could be simplified through SROA.
+  DenseMap<Value *, Value *> SROAArgValues;
+
+  // The mapping of caller Alloca values to their accumulated cost savings. If
+  // we have to disable SROA for one of the allocas, this tells us how much
+  // cost must be added.
+  DenseMap<Value *, int> SROAArgCosts;
+
+  // Keep track of values which map to a pointer base and constant offset.
+  DenseMap<Value *, std::pair<Value *, APInt> > ConstantOffsetPtrs;
+
+  // Custom simplification helper routines.
+  bool isAllocaDerivedArg(Value *V);
+  bool lookupSROAArgAndCost(Value *V, Value *&Arg,
+                            DenseMap<Value *, int>::iterator &CostIt);
+  void disableSROA(DenseMap<Value *, int>::iterator CostIt);
+  void disableSROA(Value *V);
+  void accumulateSROACost(DenseMap<Value *, int>::iterator CostIt,
+                          int InstructionCost);
+  bool isGEPOffsetConstant(GetElementPtrInst &GEP);
+  bool accumulateGEPOffset(GEPOperator &GEP, APInt &Offset);
+  bool simplifyCallSite(Function *F, CallSite CS);
+  ConstantInt *stripAndComputeInBoundsConstantOffsets(Value *&V);
+
+  /// Return true if the given argument to the function being considered for
+  /// inlining has the given attribute set either at the call site or the
+  /// function declaration.  Primarily used to inspect call site specific
+  /// attributes since these can be more precise than the ones on the callee
+  /// itself. 
+  bool paramHasAttr(Argument *A, Attribute::AttrKind Attr);
+  
+  /// Return true if the given value is known non null within the callee if
+  /// inlined through this particular callsite. 
+  bool isKnownNonNullInCallee(Value *V);
+
+  // Custom analysis routines.
+  bool analyzeBlock(BasicBlock *BB, SmallPtrSetImpl<const Value *> &EphValues);
+
+  // Disable several entry points to the visitor so we don't accidentally use
+  // them by declaring but not defining them here.
+  void visit(Module *);     void visit(Module &);
+  void visit(Function *);   void visit(Function &);
+  void visit(BasicBlock *); void visit(BasicBlock &);
+
+  // Provide base case for our instruction visit.
+  bool visitInstruction(Instruction &I);
+
+  // Our visit overrides.
+  bool visitAlloca(AllocaInst &I);
+  bool visitPHI(PHINode &I);
+  bool visitGetElementPtr(GetElementPtrInst &I);
+  bool visitBitCast(BitCastInst &I);
+  bool visitPtrToInt(PtrToIntInst &I);
+  bool visitIntToPtr(IntToPtrInst &I);
+  bool visitCastInst(CastInst &I);
+  bool visitUnaryInstruction(UnaryInstruction &I);
+  bool visitCmpInst(CmpInst &I);
+  bool visitSub(BinaryOperator &I);
+  bool visitBinaryOperator(BinaryOperator &I);
+  bool visitLoad(LoadInst &I);
+  bool visitStore(StoreInst &I);
+  bool visitExtractValue(ExtractValueInst &I);
+  bool visitInsertValue(InsertValueInst &I);
+  bool visitCallSite(CallSite CS);
+  bool visitReturnInst(ReturnInst &RI);
+  bool visitBranchInst(BranchInst &BI);
+  bool visitSwitchInst(SwitchInst &SI);
+  bool visitIndirectBrInst(IndirectBrInst &IBI);
+  bool visitResumeInst(ResumeInst &RI);
+  bool visitCleanupReturnInst(CleanupReturnInst &RI);
+  bool visitCatchReturnInst(CatchReturnInst &RI);
+  bool visitUnreachableInst(UnreachableInst &I);
+
+public:
+  CallAnalyzer(const TargetTransformInfo &TTI, AssumptionCacheTracker *ACT,
+               Function &Callee, int Threshold, CallSite CSArg)
+    : TTI(TTI), ACT(ACT), F(Callee), CandidateCS(CSArg), Threshold(Threshold),
+        Cost(0), IsCallerRecursive(false), IsRecursiveCall(false),
+        ExposesReturnsTwice(false), HasDynamicAlloca(false),
+        ContainsNoDuplicateCall(false), HasReturn(false), HasIndirectBr(false),
+        HasFrameEscape(false), AllocatedSize(0), NumInstructions(0),
+        NumVectorInstructions(0), FiftyPercentVectorBonus(0),
+        TenPercentVectorBonus(0), VectorBonus(0), NumConstantArgs(0),
+        NumConstantOffsetPtrArgs(0), NumAllocaArgs(0), NumConstantPtrCmps(0),
+        NumConstantPtrDiffs(0), NumInstructionsSimplified(0),
+        SROACostSavings(0), SROACostSavingsLost(0) {}
+
+  bool analyzeCall(CallSite CS);
+
+  int getThreshold() { return Threshold; }
+  int getCost() { return Cost; }
+
+  // Keep a bunch of stats about the cost savings found so we can print them
+  // out when debugging.
+  unsigned NumConstantArgs;
+  unsigned NumConstantOffsetPtrArgs;
+  unsigned NumAllocaArgs;
+  unsigned NumConstantPtrCmps;
+  unsigned NumConstantPtrDiffs;
+  unsigned NumInstructionsSimplified;
+  unsigned SROACostSavings;
+  unsigned SROACostSavingsLost;
+
+  void dump();
+};
+
+} // namespace
+
+/// \brief Test whether the given value is an Alloca-derived function argument.
+bool CallAnalyzer::isAllocaDerivedArg(Value *V) {
+  return SROAArgValues.count(V);
+}
+
+/// \brief Lookup the SROA-candidate argument and cost iterator which V maps to.
+/// Returns false if V does not map to a SROA-candidate.
+bool CallAnalyzer::lookupSROAArgAndCost(
+    Value *V, Value *&Arg, DenseMap<Value *, int>::iterator &CostIt) {
+  if (SROAArgValues.empty() || SROAArgCosts.empty())
+    return false;
+
+  DenseMap<Value *, Value *>::iterator ArgIt = SROAArgValues.find(V);
+  if (ArgIt == SROAArgValues.end())
+    return false;
+
+  Arg = ArgIt->second;
+  CostIt = SROAArgCosts.find(Arg);
+  return CostIt != SROAArgCosts.end();
+}
+
+/// \brief Disable SROA for the candidate marked by this cost iterator.
+///
+/// This marks the candidate as no longer viable for SROA, and adds the cost
+/// savings associated with it back into the inline cost measurement.
+void CallAnalyzer::disableSROA(DenseMap<Value *, int>::iterator CostIt) {
+  // If we're no longer able to perform SROA we need to undo its cost savings
+  // and prevent subsequent analysis.
+  Cost += CostIt->second;
+  SROACostSavings -= CostIt->second;
+  SROACostSavingsLost += CostIt->second;
+  SROAArgCosts.erase(CostIt);
+}
+
+/// \brief If 'V' maps to a SROA candidate, disable SROA for it.
+void CallAnalyzer::disableSROA(Value *V) {
+  Value *SROAArg;
+  DenseMap<Value *, int>::iterator CostIt;
+  if (lookupSROAArgAndCost(V, SROAArg, CostIt))
+    disableSROA(CostIt);
+}
+
+/// \brief Accumulate the given cost for a particular SROA candidate.
+void CallAnalyzer::accumulateSROACost(DenseMap<Value *, int>::iterator CostIt,
+                                      int InstructionCost) {
+  CostIt->second += InstructionCost;
+  SROACostSavings += InstructionCost;
+}
+
+/// \brief Check whether a GEP's indices are all constant.
+///
+/// Respects any simplified values known during the analysis of this callsite.
+bool CallAnalyzer::isGEPOffsetConstant(GetElementPtrInst &GEP) {
+  for (User::op_iterator I = GEP.idx_begin(), E = GEP.idx_end(); I != E; ++I)
+    if (!isa<Constant>(*I) && !SimplifiedValues.lookup(*I))
+      return false;
+
+  return true;
+}
+
+/// \brief Accumulate a constant GEP offset into an APInt if possible.
+///
+/// Returns false if unable to compute the offset for any reason. Respects any
+/// simplified values known during the analysis of this callsite.
+bool CallAnalyzer::accumulateGEPOffset(GEPOperator &GEP, APInt &Offset) {
+  const DataLayout &DL = F.getParent()->getDataLayout();
+  unsigned IntPtrWidth = DL.getPointerSizeInBits();
+  assert(IntPtrWidth == Offset.getBitWidth());
+
+  for (gep_type_iterator GTI = gep_type_begin(GEP), GTE = gep_type_end(GEP);
+       GTI != GTE; ++GTI) {
+    ConstantInt *OpC = dyn_cast<ConstantInt>(GTI.getOperand());
+    if (!OpC)
+      if (Constant *SimpleOp = SimplifiedValues.lookup(GTI.getOperand()))
+        OpC = dyn_cast<ConstantInt>(SimpleOp);
+    if (!OpC)
+      return false;
+    if (OpC->isZero()) continue;
+
+    // Handle a struct index, which adds its field offset to the pointer.
+    if (StructType *STy = dyn_cast<StructType>(*GTI)) {
+      unsigned ElementIdx = OpC->getZExtValue();
+      const StructLayout *SL = DL.getStructLayout(STy);
+      Offset += APInt(IntPtrWidth, SL->getElementOffset(ElementIdx));
+      continue;
+    }
+
+    APInt TypeSize(IntPtrWidth, DL.getTypeAllocSize(GTI.getIndexedType()));
+    Offset += OpC->getValue().sextOrTrunc(IntPtrWidth) * TypeSize;
+  }
+  return true;
+}
+
+bool CallAnalyzer::visitAlloca(AllocaInst &I) {
+  // Check whether inlining will turn a dynamic alloca into a static
+  // alloca, and handle that case.
+  if (I.isArrayAllocation()) {
+    if (Constant *Size = SimplifiedValues.lookup(I.getArraySize())) {
+      ConstantInt *AllocSize = dyn_cast<ConstantInt>(Size);
+      assert(AllocSize && "Allocation size not a constant int?");
+      Type *Ty = I.getAllocatedType();
+      AllocatedSize += Ty->getPrimitiveSizeInBits() * AllocSize->getZExtValue();
+      return Base::visitAlloca(I);
+    }
+  }
+
+  // Accumulate the allocated size.
+  if (I.isStaticAlloca()) {
+    const DataLayout &DL = F.getParent()->getDataLayout();
+    Type *Ty = I.getAllocatedType();
+    AllocatedSize += DL.getTypeAllocSize(Ty);
+  }
+
+  // We will happily inline static alloca instructions.
+  if (I.isStaticAlloca())
+    return Base::visitAlloca(I);
+
+  // FIXME: This is overly conservative. Dynamic allocas are inefficient for
+  // a variety of reasons, and so we would like to not inline them into
+  // functions which don't currently have a dynamic alloca. This simply
+  // disables inlining altogether in the presence of a dynamic alloca.
+  HasDynamicAlloca = true;
+  return false;
+}
+
+bool CallAnalyzer::visitPHI(PHINode &I) {
+  // FIXME: We should potentially be tracking values through phi nodes,
+  // especially when they collapse to a single value due to deleted CFG edges
+  // during inlining.
+
+  // FIXME: We need to propagate SROA *disabling* through phi nodes, even
+  // though we don't want to propagate it's bonuses. The idea is to disable
+  // SROA if it *might* be used in an inappropriate manner.
+
+  // Phi nodes are always zero-cost.
+  return true;
+}
+
+bool CallAnalyzer::visitGetElementPtr(GetElementPtrInst &I) {
+  Value *SROAArg;
+  DenseMap<Value *, int>::iterator CostIt;
+  bool SROACandidate = lookupSROAArgAndCost(I.getPointerOperand(),
+                                            SROAArg, CostIt);
+
+  // Try to fold GEPs of constant-offset call site argument pointers. This
+  // requires target data and inbounds GEPs.
+  if (I.isInBounds()) {
+    // Check if we have a base + offset for the pointer.
+    Value *Ptr = I.getPointerOperand();
+    std::pair<Value *, APInt> BaseAndOffset = ConstantOffsetPtrs.lookup(Ptr);
+    if (BaseAndOffset.first) {
+      // Check if the offset of this GEP is constant, and if so accumulate it
+      // into Offset.
+      if (!accumulateGEPOffset(cast<GEPOperator>(I), BaseAndOffset.second)) {
+        // Non-constant GEPs aren't folded, and disable SROA.
+        if (SROACandidate)
+          disableSROA(CostIt);
+        return false;
+      }
+
+      // Add the result as a new mapping to Base + Offset.
+      ConstantOffsetPtrs[&I] = BaseAndOffset;
+
+      // Also handle SROA candidates here, we already know that the GEP is
+      // all-constant indexed.
+      if (SROACandidate)
+        SROAArgValues[&I] = SROAArg;
+
+      return true;
+    }
+  }
+
+  if (isGEPOffsetConstant(I)) {
+    if (SROACandidate)
+      SROAArgValues[&I] = SROAArg;
+
+    // Constant GEPs are modeled as free.
+    return true;
+  }
+
+  // Variable GEPs will require math and will disable SROA.
+  if (SROACandidate)
+    disableSROA(CostIt);
+  return false;
+}
+
+bool CallAnalyzer::visitBitCast(BitCastInst &I) {
+  // Propagate constants through bitcasts.
+  Constant *COp = dyn_cast<Constant>(I.getOperand(0));
+  if (!COp)
+    COp = SimplifiedValues.lookup(I.getOperand(0));
+  if (COp)
+    if (Constant *C = ConstantExpr::getBitCast(COp, I.getType())) {
+      SimplifiedValues[&I] = C;
+      return true;
+    }
+
+  // Track base/offsets through casts
+  std::pair<Value *, APInt> BaseAndOffset
+    = ConstantOffsetPtrs.lookup(I.getOperand(0));
+  // Casts don't change the offset, just wrap it up.
+  if (BaseAndOffset.first)
+    ConstantOffsetPtrs[&I] = BaseAndOffset;
+
+  // Also look for SROA candidates here.
+  Value *SROAArg;
+  DenseMap<Value *, int>::iterator CostIt;
+  if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt))
+    SROAArgValues[&I] = SROAArg;
+
+  // Bitcasts are always zero cost.
+  return true;
+}
+
+bool CallAnalyzer::visitPtrToInt(PtrToIntInst &I) {
+  // Propagate constants through ptrtoint.
+  Constant *COp = dyn_cast<Constant>(I.getOperand(0));
+  if (!COp)
+    COp = SimplifiedValues.lookup(I.getOperand(0));
+  if (COp)
+    if (Constant *C = ConstantExpr::getPtrToInt(COp, I.getType())) {
+      SimplifiedValues[&I] = C;
+      return true;
+    }
+
+  // Track base/offset pairs when converted to a plain integer provided the
+  // integer is large enough to represent the pointer.
+  unsigned IntegerSize = I.getType()->getScalarSizeInBits();
+  const DataLayout &DL = F.getParent()->getDataLayout();
+  if (IntegerSize >= DL.getPointerSizeInBits()) {
+    std::pair<Value *, APInt> BaseAndOffset
+      = ConstantOffsetPtrs.lookup(I.getOperand(0));
+    if (BaseAndOffset.first)
+      ConstantOffsetPtrs[&I] = BaseAndOffset;
+  }
+
+  // This is really weird. Technically, ptrtoint will disable SROA. However,
+  // unless that ptrtoint is *used* somewhere in the live basic blocks after
+  // inlining, it will be nuked, and SROA should proceed. All of the uses which
+  // would block SROA would also block SROA if applied directly to a pointer,
+  // and so we can just add the integer in here. The only places where SROA is
+  // preserved either cannot fire on an integer, or won't in-and-of themselves
+  // disable SROA (ext) w/o some later use that we would see and disable.
+  Value *SROAArg;
+  DenseMap<Value *, int>::iterator CostIt;
+  if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt))
+    SROAArgValues[&I] = SROAArg;
+
+  return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I);
+}
+
+bool CallAnalyzer::visitIntToPtr(IntToPtrInst &I) {
+  // Propagate constants through ptrtoint.
+  Constant *COp = dyn_cast<Constant>(I.getOperand(0));
+  if (!COp)
+    COp = SimplifiedValues.lookup(I.getOperand(0));
+  if (COp)
+    if (Constant *C = ConstantExpr::getIntToPtr(COp, I.getType())) {
+      SimplifiedValues[&I] = C;
+      return true;
+    }
+
+  // Track base/offset pairs when round-tripped through a pointer without
+  // modifications provided the integer is not too large.
+  Value *Op = I.getOperand(0);
+  unsigned IntegerSize = Op->getType()->getScalarSizeInBits();
+  const DataLayout &DL = F.getParent()->getDataLayout();
+  if (IntegerSize <= DL.getPointerSizeInBits()) {
+    std::pair<Value *, APInt> BaseAndOffset = ConstantOffsetPtrs.lookup(Op);
+    if (BaseAndOffset.first)
+      ConstantOffsetPtrs[&I] = BaseAndOffset;
+  }
+
+  // "Propagate" SROA here in the same manner as we do for ptrtoint above.
+  Value *SROAArg;
+  DenseMap<Value *, int>::iterator CostIt;
+  if (lookupSROAArgAndCost(Op, SROAArg, CostIt))
+    SROAArgValues[&I] = SROAArg;
+
+  return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I);
+}
+
+bool CallAnalyzer::visitCastInst(CastInst &I) {
+  // Propagate constants through ptrtoint.
+  Constant *COp = dyn_cast<Constant>(I.getOperand(0));
+  if (!COp)
+    COp = SimplifiedValues.lookup(I.getOperand(0));
+  if (COp)
+    if (Constant *C = ConstantExpr::getCast(I.getOpcode(), COp, I.getType())) {
+      SimplifiedValues[&I] = C;
+      return true;
+    }
+
+  // Disable SROA in the face of arbitrary casts we don't whitelist elsewhere.
+  disableSROA(I.getOperand(0));
+
+  return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I);
+}
+
+bool CallAnalyzer::visitUnaryInstruction(UnaryInstruction &I) {
+  Value *Operand = I.getOperand(0);
+  Constant *COp = dyn_cast<Constant>(Operand);
+  if (!COp)
+    COp = SimplifiedValues.lookup(Operand);
+  if (COp) {
+    const DataLayout &DL = F.getParent()->getDataLayout();
+    if (Constant *C = ConstantFoldInstOperands(I.getOpcode(), I.getType(),
+                                               COp, DL)) {
+      SimplifiedValues[&I] = C;
+      return true;
+    }
+  }
+
+  // Disable any SROA on the argument to arbitrary unary operators.
+  disableSROA(Operand);
+
+  return false;
+}
+
+bool CallAnalyzer::paramHasAttr(Argument *A, Attribute::AttrKind Attr) {
+  unsigned ArgNo = A->getArgNo();
+  return CandidateCS.paramHasAttr(ArgNo+1, Attr);
+}
+
+bool CallAnalyzer::isKnownNonNullInCallee(Value *V) {
+  // Does the *call site* have the NonNull attribute set on an argument?  We
+  // use the attribute on the call site to memoize any analysis done in the
+  // caller. This will also trip if the callee function has a non-null
+  // parameter attribute, but that's a less interesting case because hopefully
+  // the callee would already have been simplified based on that.
+  if (Argument *A = dyn_cast<Argument>(V))
+    if (paramHasAttr(A, Attribute::NonNull))
+      return true;
+  
+  // Is this an alloca in the caller?  This is distinct from the attribute case
+  // above because attributes aren't updated within the inliner itself and we
+  // always want to catch the alloca derived case.
+  if (isAllocaDerivedArg(V))
+    // We can actually predict the result of comparisons between an
+    // alloca-derived value and null. Note that this fires regardless of
+    // SROA firing.
+    return true;
+  
+  return false;
+}
+
+bool CallAnalyzer::visitCmpInst(CmpInst &I) {
+  Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
+  // First try to handle simplified comparisons.
+  if (!isa<Constant>(LHS))
+    if (Constant *SimpleLHS = SimplifiedValues.lookup(LHS))
+      LHS = SimpleLHS;
+  if (!isa<Constant>(RHS))
+    if (Constant *SimpleRHS = SimplifiedValues.lookup(RHS))
+      RHS = SimpleRHS;
+  if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
+    if (Constant *CRHS = dyn_cast<Constant>(RHS))
+      if (Constant *C = ConstantExpr::getCompare(I.getPredicate(), CLHS, CRHS)) {
+        SimplifiedValues[&I] = C;
+        return true;
+      }
+  }
+
+  if (I.getOpcode() == Instruction::FCmp)
+    return false;
+
+  // Otherwise look for a comparison between constant offset pointers with
+  // a common base.
+  Value *LHSBase, *RHSBase;
+  APInt LHSOffset, RHSOffset;
+  std::tie(LHSBase, LHSOffset) = ConstantOffsetPtrs.lookup(LHS);
+  if (LHSBase) {
+    std::tie(RHSBase, RHSOffset) = ConstantOffsetPtrs.lookup(RHS);
+    if (RHSBase && LHSBase == RHSBase) {
+      // We have common bases, fold the icmp to a constant based on the
+      // offsets.
+      Constant *CLHS = ConstantInt::get(LHS->getContext(), LHSOffset);
+      Constant *CRHS = ConstantInt::get(RHS->getContext(), RHSOffset);
+      if (Constant *C = ConstantExpr::getICmp(I.getPredicate(), CLHS, CRHS)) {
+        SimplifiedValues[&I] = C;
+        ++NumConstantPtrCmps;
+        return true;
+      }
+    }
+  }
+
+  // If the comparison is an equality comparison with null, we can simplify it
+  // if we know the value (argument) can't be null
+  if (I.isEquality() && isa<ConstantPointerNull>(I.getOperand(1)) &&
+      isKnownNonNullInCallee(I.getOperand(0))) {
+    bool IsNotEqual = I.getPredicate() == CmpInst::ICMP_NE;
+    SimplifiedValues[&I] = IsNotEqual ? ConstantInt::getTrue(I.getType())
+                                      : ConstantInt::getFalse(I.getType());
+    return true;
+  }
+  // Finally check for SROA candidates in comparisons.
+  Value *SROAArg;
+  DenseMap<Value *, int>::iterator CostIt;
+  if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt)) {
+    if (isa<ConstantPointerNull>(I.getOperand(1))) {
+      accumulateSROACost(CostIt, InlineConstants::InstrCost);
+      return true;
+    }
+
+    disableSROA(CostIt);
+  }
+
+  return false;
+}
+
+bool CallAnalyzer::visitSub(BinaryOperator &I) {
+  // Try to handle a special case: we can fold computing the difference of two
+  // constant-related pointers.
+  Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
+  Value *LHSBase, *RHSBase;
+  APInt LHSOffset, RHSOffset;
+  std::tie(LHSBase, LHSOffset) = ConstantOffsetPtrs.lookup(LHS);
+  if (LHSBase) {
+    std::tie(RHSBase, RHSOffset) = ConstantOffsetPtrs.lookup(RHS);
+    if (RHSBase && LHSBase == RHSBase) {
+      // We have common bases, fold the subtract to a constant based on the
+      // offsets.
+      Constant *CLHS = ConstantInt::get(LHS->getContext(), LHSOffset);
+      Constant *CRHS = ConstantInt::get(RHS->getContext(), RHSOffset);
+      if (Constant *C = ConstantExpr::getSub(CLHS, CRHS)) {
+        SimplifiedValues[&I] = C;
+        ++NumConstantPtrDiffs;
+        return true;
+      }
+    }
+  }
+
+  // Otherwise, fall back to the generic logic for simplifying and handling
+  // instructions.
+  return Base::visitSub(I);
+}
+
+bool CallAnalyzer::visitBinaryOperator(BinaryOperator &I) {
+  Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
+  const DataLayout &DL = F.getParent()->getDataLayout();
+  if (!isa<Constant>(LHS))
+    if (Constant *SimpleLHS = SimplifiedValues.lookup(LHS))
+      LHS = SimpleLHS;
+  if (!isa<Constant>(RHS))
+    if (Constant *SimpleRHS = SimplifiedValues.lookup(RHS))
+      RHS = SimpleRHS;
+  Value *SimpleV = nullptr;
+  if (auto FI = dyn_cast<FPMathOperator>(&I))
+    SimpleV =
+        SimplifyFPBinOp(I.getOpcode(), LHS, RHS, FI->getFastMathFlags(), DL);
+  else
+    SimpleV = SimplifyBinOp(I.getOpcode(), LHS, RHS, DL);
+
+  if (Constant *C = dyn_cast_or_null<Constant>(SimpleV)) {
+    SimplifiedValues[&I] = C;
+    return true;
+  }
+
+  // Disable any SROA on arguments to arbitrary, unsimplified binary operators.
+  disableSROA(LHS);
+  disableSROA(RHS);
+
+  return false;
+}
+
+bool CallAnalyzer::visitLoad(LoadInst &I) {
+  Value *SROAArg;
+  DenseMap<Value *, int>::iterator CostIt;
+  if (lookupSROAArgAndCost(I.getPointerOperand(), SROAArg, CostIt)) {
+    if (I.isSimple()) {
+      accumulateSROACost(CostIt, InlineConstants::InstrCost);
+      return true;
+    }
+
+    disableSROA(CostIt);
+  }
+
+  return false;
+}
+
+bool CallAnalyzer::visitStore(StoreInst &I) {
+  Value *SROAArg;
+  DenseMap<Value *, int>::iterator CostIt;
+  if (lookupSROAArgAndCost(I.getPointerOperand(), SROAArg, CostIt)) {
+    if (I.isSimple()) {
+      accumulateSROACost(CostIt, InlineConstants::InstrCost);
+      return true;
+    }
+
+    disableSROA(CostIt);
+  }
+
+  return false;
+}
+
+bool CallAnalyzer::visitExtractValue(ExtractValueInst &I) {
+  // Constant folding for extract value is trivial.
+  Constant *C = dyn_cast<Constant>(I.getAggregateOperand());
+  if (!C)
+    C = SimplifiedValues.lookup(I.getAggregateOperand());
+  if (C) {
+    SimplifiedValues[&I] = ConstantExpr::getExtractValue(C, I.getIndices());
+    return true;
+  }
+
+  // SROA can look through these but give them a cost.
+  return false;
+}
+
+bool CallAnalyzer::visitInsertValue(InsertValueInst &I) {
+  // Constant folding for insert value is trivial.
+  Constant *AggC = dyn_cast<Constant>(I.getAggregateOperand());
+  if (!AggC)
+    AggC = SimplifiedValues.lookup(I.getAggregateOperand());
+  Constant *InsertedC = dyn_cast<Constant>(I.getInsertedValueOperand());
+  if (!InsertedC)
+    InsertedC = SimplifiedValues.lookup(I.getInsertedValueOperand());
+  if (AggC && InsertedC) {
+    SimplifiedValues[&I] = ConstantExpr::getInsertValue(AggC, InsertedC,
+                                                        I.getIndices());
+    return true;
+  }
+
+  // SROA can look through these but give them a cost.
+  return false;
+}
+
+/// \brief Try to simplify a call site.
+///
+/// Takes a concrete function and callsite and tries to actually simplify it by
+/// analyzing the arguments and call itself with instsimplify. Returns true if
+/// it has simplified the callsite to some other entity (a constant), making it
+/// free.
+bool CallAnalyzer::simplifyCallSite(Function *F, CallSite CS) {
+  // FIXME: Using the instsimplify logic directly for this is inefficient
+  // because we have to continually rebuild the argument list even when no
+  // simplifications can be performed. Until that is fixed with remapping
+  // inside of instsimplify, directly constant fold calls here.
+  if (!canConstantFoldCallTo(F))
+    return false;
+
+  // Try to re-map the arguments to constants.
+  SmallVector<Constant *, 4> ConstantArgs;
+  ConstantArgs.reserve(CS.arg_size());
+  for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
+       I != E; ++I) {
+    Constant *C = dyn_cast<Constant>(*I);
+    if (!C)
+      C = dyn_cast_or_null<Constant>(SimplifiedValues.lookup(*I));
+    if (!C)
+      return false; // This argument doesn't map to a constant.
+
+    ConstantArgs.push_back(C);
+  }
+  if (Constant *C = ConstantFoldCall(F, ConstantArgs)) {
+    SimplifiedValues[CS.getInstruction()] = C;
+    return true;
+  }
+
+  return false;
+}
+
+bool CallAnalyzer::visitCallSite(CallSite CS) {
+  if (CS.hasFnAttr(Attribute::ReturnsTwice) &&
+      !F.hasFnAttribute(Attribute::ReturnsTwice)) {
+    // This aborts the entire analysis.
+    ExposesReturnsTwice = true;
+    return false;
+  }
+  if (CS.isCall() &&
+      cast<CallInst>(CS.getInstruction())->cannotDuplicate())
+    ContainsNoDuplicateCall = true;
+
+  if (Function *F = CS.getCalledFunction()) {
+    // When we have a concrete function, first try to simplify it directly.
+    if (simplifyCallSite(F, CS))
+      return true;
+
+    // Next check if it is an intrinsic we know about.
+    // FIXME: Lift this into part of the InstVisitor.
+    if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(CS.getInstruction())) {
+      switch (II->getIntrinsicID()) {
+      default:
+        return Base::visitCallSite(CS);
+
+      case Intrinsic::memset:
+      case Intrinsic::memcpy:
+      case Intrinsic::memmove:
+        // SROA can usually chew through these intrinsics, but they aren't free.
+        return false;
+      case Intrinsic::localescape:
+        HasFrameEscape = true;
+        return false;
+      }
+    }
+
+    if (F == CS.getInstruction()->getParent()->getParent()) {
+      // This flag will fully abort the analysis, so don't bother with anything
+      // else.
+      IsRecursiveCall = true;
+      return false;
+    }
+
+    if (TTI.isLoweredToCall(F)) {
+      // We account for the average 1 instruction per call argument setup
+      // here.
+      Cost += CS.arg_size() * InlineConstants::InstrCost;
+
+      // Everything other than inline ASM will also have a significant cost
+      // merely from making the call.
+      if (!isa<InlineAsm>(CS.getCalledValue()))
+        Cost += InlineConstants::CallPenalty;
+    }
+
+    return Base::visitCallSite(CS);
+  }
+
+  // Otherwise we're in a very special case -- an indirect function call. See
+  // if we can be particularly clever about this.
+  Value *Callee = CS.getCalledValue();
+
+  // First, pay the price of the argument setup. We account for the average
+  // 1 instruction per call argument setup here.
+  Cost += CS.arg_size() * InlineConstants::InstrCost;
+
+  // Next, check if this happens to be an indirect function call to a known
+  // function in this inline context. If not, we've done all we can.
+  Function *F = dyn_cast_or_null<Function>(SimplifiedValues.lookup(Callee));
+  if (!F)
+    return Base::visitCallSite(CS);
+
+  // If we have a constant that we are calling as a function, we can peer
+  // through it and see the function target. This happens not infrequently
+  // during devirtualization and so we want to give it a hefty bonus for
+  // inlining, but cap that bonus in the event that inlining wouldn't pan
+  // out. Pretend to inline the function, with a custom threshold.
+  CallAnalyzer CA(TTI, ACT, *F, InlineConstants::IndirectCallThreshold, CS);
+  if (CA.analyzeCall(CS)) {
+    // We were able to inline the indirect call! Subtract the cost from the
+    // bonus we want to apply, but don't go below zero.
+    Cost -= std::max(0, InlineConstants::IndirectCallThreshold - CA.getCost());
+  }
+
+  return Base::visitCallSite(CS);
+}
+
+bool CallAnalyzer::visitReturnInst(ReturnInst &RI) {
+  // At least one return instruction will be free after inlining.
+  bool Free = !HasReturn;
+  HasReturn = true;
+  return Free;
+}
+
+bool CallAnalyzer::visitBranchInst(BranchInst &BI) {
+  // We model unconditional branches as essentially free -- they really
+  // shouldn't exist at all, but handling them makes the behavior of the
+  // inliner more regular and predictable. Interestingly, conditional branches
+  // which will fold away are also free.
+  return BI.isUnconditional() || isa<ConstantInt>(BI.getCondition()) ||
+         dyn_cast_or_null<ConstantInt>(
+             SimplifiedValues.lookup(BI.getCondition()));
+}
+
+bool CallAnalyzer::visitSwitchInst(SwitchInst &SI) {
+  // We model unconditional switches as free, see the comments on handling
+  // branches.
+  if (isa<ConstantInt>(SI.getCondition()))
+    return true;
+  if (Value *V = SimplifiedValues.lookup(SI.getCondition()))
+    if (isa<ConstantInt>(V))
+      return true;
+
+  // Otherwise, we need to accumulate a cost proportional to the number of
+  // distinct successor blocks. This fan-out in the CFG cannot be represented
+  // for free even if we can represent the core switch as a jumptable that
+  // takes a single instruction.
+  //
+  // NB: We convert large switches which are just used to initialize large phi
+  // nodes to lookup tables instead in simplify-cfg, so this shouldn't prevent
+  // inlining those. It will prevent inlining in cases where the optimization
+  // does not (yet) fire.
+  SmallPtrSet<BasicBlock *, 8> SuccessorBlocks;
+  SuccessorBlocks.insert(SI.getDefaultDest());
+  for (auto I = SI.case_begin(), E = SI.case_end(); I != E; ++I)
+    SuccessorBlocks.insert(I.getCaseSuccessor());
+  // Add cost corresponding to the number of distinct destinations. The first
+  // we model as free because of fallthrough.
+  Cost += (SuccessorBlocks.size() - 1) * InlineConstants::InstrCost;
+  return false;
+}
+
+bool CallAnalyzer::visitIndirectBrInst(IndirectBrInst &IBI) {
+  // We never want to inline functions that contain an indirectbr.  This is
+  // incorrect because all the blockaddress's (in static global initializers
+  // for example) would be referring to the original function, and this
+  // indirect jump would jump from the inlined copy of the function into the
+  // original function which is extremely undefined behavior.
+  // FIXME: This logic isn't really right; we can safely inline functions with
+  // indirectbr's as long as no other function or global references the
+  // blockaddress of a block within the current function.
+  HasIndirectBr = true;
+  return false;
+}
+
+bool CallAnalyzer::visitResumeInst(ResumeInst &RI) {
+  // FIXME: It's not clear that a single instruction is an accurate model for
+  // the inline cost of a resume instruction.
+  return false;
+}
+
+bool CallAnalyzer::visitCleanupReturnInst(CleanupReturnInst &CRI) {
+  // FIXME: It's not clear that a single instruction is an accurate model for
+  // the inline cost of a cleanupret instruction.
+  return false;
+}
+
+bool CallAnalyzer::visitCatchReturnInst(CatchReturnInst &CRI) {
+  // FIXME: It's not clear that a single instruction is an accurate model for
+  // the inline cost of a cleanupret instruction.
+  return false;
+}
+
+bool CallAnalyzer::visitUnreachableInst(UnreachableInst &I) {
+  // FIXME: It might be reasonably to discount the cost of instructions leading
+  // to unreachable as they have the lowest possible impact on both runtime and
+  // code size.
+  return true; // No actual code is needed for unreachable.
+}
+
+bool CallAnalyzer::visitInstruction(Instruction &I) {
+  // Some instructions are free. All of the free intrinsics can also be
+  // handled by SROA, etc.
+  if (TargetTransformInfo::TCC_Free == TTI.getUserCost(&I))
+    return true;
+
+  // We found something we don't understand or can't handle. Mark any SROA-able
+  // values in the operand list as no longer viable.
+  for (User::op_iterator OI = I.op_begin(), OE = I.op_end(); OI != OE; ++OI)
+    disableSROA(*OI);
+
+  return false;
+}
+
+
+/// \brief Analyze a basic block for its contribution to the inline cost.
+///
+/// This method walks the analyzer over every instruction in the given basic
+/// block and accounts for their cost during inlining at this callsite. It
+/// aborts early if the threshold has been exceeded or an impossible to inline
+/// construct has been detected. It returns false if inlining is no longer
+/// viable, and true if inlining remains viable.
+bool CallAnalyzer::analyzeBlock(BasicBlock *BB,
+                                SmallPtrSetImpl<const Value *> &EphValues) {
+  for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
+    // FIXME: Currently, the number of instructions in a function regardless of
+    // our ability to simplify them during inline to constants or dead code,
+    // are actually used by the vector bonus heuristic. As long as that's true,
+    // we have to special case debug intrinsics here to prevent differences in
+    // inlining due to debug symbols. Eventually, the number of unsimplified
+    // instructions shouldn't factor into the cost computation, but until then,
+    // hack around it here.
+    if (isa<DbgInfoIntrinsic>(I))
+      continue;
+
+    // Skip ephemeral values.
+    if (EphValues.count(I))
+      continue;
+
+    ++NumInstructions;
+    if (isa<ExtractElementInst>(I) || I->getType()->isVectorTy())
+      ++NumVectorInstructions;
+
+    // If the instruction is floating point, and the target says this operation is
+    // expensive or the function has the "use-soft-float" attribute, this may
+    // eventually become a library call.  Treat the cost as such.
+    if (I->getType()->isFloatingPointTy()) {
+      bool hasSoftFloatAttr = false;
+
+      // If the function has the "use-soft-float" attribute, mark it as expensive.
+      if (F.hasFnAttribute("use-soft-float")) {
+        Attribute Attr = F.getFnAttribute("use-soft-float");
+        StringRef Val = Attr.getValueAsString();
+        if (Val == "true")
+          hasSoftFloatAttr = true;
+      }
+
+      if (TTI.getFPOpCost(I->getType()) == TargetTransformInfo::TCC_Expensive ||
+          hasSoftFloatAttr)
+        Cost += InlineConstants::CallPenalty;
+    }
+
+    // If the instruction simplified to a constant, there is no cost to this
+    // instruction. Visit the instructions using our InstVisitor to account for
+    // all of the per-instruction logic. The visit tree returns true if we
+    // consumed the instruction in any way, and false if the instruction's base
+    // cost should count against inlining.
+    if (Base::visit(I))
+      ++NumInstructionsSimplified;
+    else
+      Cost += InlineConstants::InstrCost;
+
+    // If the visit this instruction detected an uninlinable pattern, abort.
+    if (IsRecursiveCall || ExposesReturnsTwice || HasDynamicAlloca ||
+        HasIndirectBr || HasFrameEscape)
+      return false;
+
+    // If the caller is a recursive function then we don't want to inline
+    // functions which allocate a lot of stack space because it would increase
+    // the caller stack usage dramatically.
+    if (IsCallerRecursive &&
+        AllocatedSize > InlineConstants::TotalAllocaSizeRecursiveCaller)
+      return false;
+
+    // Check if we've past the maximum possible threshold so we don't spin in
+    // huge basic blocks that will never inline.
+    if (Cost > Threshold)
+      return false;
+  }
+
+  return true;
+}
+
+/// \brief Compute the base pointer and cumulative constant offsets for V.
+///
+/// This strips all constant offsets off of V, leaving it the base pointer, and
+/// accumulates the total constant offset applied in the returned constant. It
+/// returns 0 if V is not a pointer, and returns the constant '0' if there are
+/// no constant offsets applied.
+ConstantInt *CallAnalyzer::stripAndComputeInBoundsConstantOffsets(Value *&V) {
+  if (!V->getType()->isPointerTy())
+    return nullptr;
+
+  const DataLayout &DL = F.getParent()->getDataLayout();
+  unsigned IntPtrWidth = DL.getPointerSizeInBits();
+  APInt Offset = APInt::getNullValue(IntPtrWidth);
+
+  // Even though we don't look through PHI nodes, we could be called on an
+  // instruction in an unreachable block, which may be on a cycle.
+  SmallPtrSet<Value *, 4> Visited;
+  Visited.insert(V);
+  do {
+    if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
+      if (!GEP->isInBounds() || !accumulateGEPOffset(*GEP, Offset))
+        return nullptr;
+      V = GEP->getPointerOperand();
+    } else if (Operator::getOpcode(V) == Instruction::BitCast) {
+      V = cast<Operator>(V)->getOperand(0);
+    } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) {
+      if (GA->mayBeOverridden())
+        break;
+      V = GA->getAliasee();
+    } else {
+      break;
+    }
+    assert(V->getType()->isPointerTy() && "Unexpected operand type!");
+  } while (Visited.insert(V).second);
+
+  Type *IntPtrTy = DL.getIntPtrType(V->getContext());
+  return cast<ConstantInt>(ConstantInt::get(IntPtrTy, Offset));
+}
+
+/// \brief Analyze a call site for potential inlining.
+///
+/// Returns true if inlining this call is viable, and false if it is not
+/// viable. It computes the cost and adjusts the threshold based on numerous
+/// factors and heuristics. If this method returns false but the computed cost
+/// is below the computed threshold, then inlining was forcibly disabled by
+/// some artifact of the routine.
+bool CallAnalyzer::analyzeCall(CallSite CS) {
+  ++NumCallsAnalyzed;
+
+  // Perform some tweaks to the cost and threshold based on the direct
+  // callsite information.
+
+  // We want to more aggressively inline vector-dense kernels, so up the
+  // threshold, and we'll lower it if the % of vector instructions gets too
+  // low. Note that these bonuses are some what arbitrary and evolved over time
+  // by accident as much as because they are principled bonuses.
+  //
+  // FIXME: It would be nice to remove all such bonuses. At least it would be
+  // nice to base the bonus values on something more scientific.
+  assert(NumInstructions == 0);
+  assert(NumVectorInstructions == 0);
+  FiftyPercentVectorBonus = 3 * Threshold / 2;
+  TenPercentVectorBonus = 3 * Threshold / 4;
+  const DataLayout &DL = F.getParent()->getDataLayout();
+
+  // Track whether the post-inlining function would have more than one basic
+  // block. A single basic block is often intended for inlining. Balloon the
+  // threshold by 50% until we pass the single-BB phase.
+  bool SingleBB = true;
+  int SingleBBBonus = Threshold / 2;
+
+  // Speculatively apply all possible bonuses to Threshold. If cost exceeds
+  // this Threshold any time, and cost cannot decrease, we can stop processing
+  // the rest of the function body.
+  Threshold += (SingleBBBonus + FiftyPercentVectorBonus);
+
+  // Give out bonuses per argument, as the instructions setting them up will
+  // be gone after inlining.
+  for (unsigned I = 0, E = CS.arg_size(); I != E; ++I) {
+    if (CS.isByValArgument(I)) {
+      // We approximate the number of loads and stores needed by dividing the
+      // size of the byval type by the target's pointer size.
+      PointerType *PTy = cast<PointerType>(CS.getArgument(I)->getType());
+      unsigned TypeSize = DL.getTypeSizeInBits(PTy->getElementType());
+      unsigned PointerSize = DL.getPointerSizeInBits();
+      // Ceiling division.
+      unsigned NumStores = (TypeSize + PointerSize - 1) / PointerSize;
+
+      // If it generates more than 8 stores it is likely to be expanded as an
+      // inline memcpy so we take that as an upper bound. Otherwise we assume
+      // one load and one store per word copied.
+      // FIXME: The maxStoresPerMemcpy setting from the target should be used
+      // here instead of a magic number of 8, but it's not available via
+      // DataLayout.
+      NumStores = std::min(NumStores, 8U);
+
+      Cost -= 2 * NumStores * InlineConstants::InstrCost;
+    } else {
+      // For non-byval arguments subtract off one instruction per call
+      // argument.
+      Cost -= InlineConstants::InstrCost;
+    }
+  }
+
+  // If there is only one call of the function, and it has internal linkage,
+  // the cost of inlining it drops dramatically.
+  bool OnlyOneCallAndLocalLinkage = F.hasLocalLinkage() && F.hasOneUse() &&
+    &F == CS.getCalledFunction();
+  if (OnlyOneCallAndLocalLinkage)
+    Cost += InlineConstants::LastCallToStaticBonus;
+
+  // If the instruction after the call, or if the normal destination of the
+  // invoke is an unreachable instruction, the function is noreturn. As such,
+  // there is little point in inlining this unless there is literally zero
+  // cost.
+  Instruction *Instr = CS.getInstruction();
+  if (InvokeInst *II = dyn_cast<InvokeInst>(Instr)) {
+    if (isa<UnreachableInst>(II->getNormalDest()->begin()))
+      Threshold = 0;
+  } else if (isa<UnreachableInst>(++BasicBlock::iterator(Instr)))
+    Threshold = 0;
+
+  // If this function uses the coldcc calling convention, prefer not to inline
+  // it.
+  if (F.getCallingConv() == CallingConv::Cold)
+    Cost += InlineConstants::ColdccPenalty;
+
+  // Check if we're done. This can happen due to bonuses and penalties.
+  if (Cost > Threshold)
+    return false;
+
+  if (F.empty())
+    return true;
+
+  Function *Caller = CS.getInstruction()->getParent()->getParent();
+  // Check if the caller function is recursive itself.
+  for (User *U : Caller->users()) {
+    CallSite Site(U);
+    if (!Site)
+      continue;
+    Instruction *I = Site.getInstruction();
+    if (I->getParent()->getParent() == Caller) {
+      IsCallerRecursive = true;
+      break;
+    }
+  }
+
+  // Populate our simplified values by mapping from function arguments to call
+  // arguments with known important simplifications.
+  CallSite::arg_iterator CAI = CS.arg_begin();
+  for (Function::arg_iterator FAI = F.arg_begin(), FAE = F.arg_end();
+       FAI != FAE; ++FAI, ++CAI) {
+    assert(CAI != CS.arg_end());
+    if (Constant *C = dyn_cast<Constant>(CAI))
+      SimplifiedValues[FAI] = C;
+
+    Value *PtrArg = *CAI;
+    if (ConstantInt *C = stripAndComputeInBoundsConstantOffsets(PtrArg)) {
+      ConstantOffsetPtrs[FAI] = std::make_pair(PtrArg, C->getValue());
+
+      // We can SROA any pointer arguments derived from alloca instructions.
+      if (isa<AllocaInst>(PtrArg)) {
+        SROAArgValues[FAI] = PtrArg;
+        SROAArgCosts[PtrArg] = 0;
+      }
+    }
+  }
+  NumConstantArgs = SimplifiedValues.size();
+  NumConstantOffsetPtrArgs = ConstantOffsetPtrs.size();
+  NumAllocaArgs = SROAArgValues.size();
+
+  // FIXME: If a caller has multiple calls to a callee, we end up recomputing
+  // the ephemeral values multiple times (and they're completely determined by
+  // the callee, so this is purely duplicate work).
+  SmallPtrSet<const Value *, 32> EphValues;
+  CodeMetrics::collectEphemeralValues(&F, &ACT->getAssumptionCache(F), EphValues);
+
+  // The worklist of live basic blocks in the callee *after* inlining. We avoid
+  // adding basic blocks of the callee which can be proven to be dead for this
+  // particular call site in order to get more accurate cost estimates. This
+  // requires a somewhat heavyweight iteration pattern: we need to walk the
+  // basic blocks in a breadth-first order as we insert live successors. To
+  // accomplish this, prioritizing for small iterations because we exit after
+  // crossing our threshold, we use a small-size optimized SetVector.
+  typedef SetVector<BasicBlock *, SmallVector<BasicBlock *, 16>,
+                                  SmallPtrSet<BasicBlock *, 16> > BBSetVector;
+  BBSetVector BBWorklist;
+  BBWorklist.insert(&F.getEntryBlock());
+  // Note that we *must not* cache the size, this loop grows the worklist.
+  for (unsigned Idx = 0; Idx != BBWorklist.size(); ++Idx) {
+    // Bail out the moment we cross the threshold. This means we'll under-count
+    // the cost, but only when undercounting doesn't matter.
+    if (Cost > Threshold)
+      break;
+
+    BasicBlock *BB = BBWorklist[Idx];
+    if (BB->empty())
+      continue;
+
+    // Disallow inlining a blockaddress. A blockaddress only has defined
+    // behavior for an indirect branch in the same function, and we do not
+    // currently support inlining indirect branches. But, the inliner may not
+    // see an indirect branch that ends up being dead code at a particular call
+    // site. If the blockaddress escapes the function, e.g., via a global
+    // variable, inlining may lead to an invalid cross-function reference.
+    if (BB->hasAddressTaken())
+      return false;
+
+    // Analyze the cost of this block. If we blow through the threshold, this
+    // returns false, and we can bail on out.
+    if (!analyzeBlock(BB, EphValues)) {
+      if (IsRecursiveCall || ExposesReturnsTwice || HasDynamicAlloca ||
+          HasIndirectBr || HasFrameEscape)
+        return false;
+
+      // If the caller is a recursive function then we don't want to inline
+      // functions which allocate a lot of stack space because it would increase
+      // the caller stack usage dramatically.
+      if (IsCallerRecursive &&
+          AllocatedSize > InlineConstants::TotalAllocaSizeRecursiveCaller)
+        return false;
+
+      break;
+    }
+
+    TerminatorInst *TI = BB->getTerminator();
+
+    // Add in the live successors by first checking whether we have terminator
+    // that may be simplified based on the values simplified by this call.
+    if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
+      if (BI->isConditional()) {
+        Value *Cond = BI->getCondition();
+        if (ConstantInt *SimpleCond
+              = dyn_cast_or_null<ConstantInt>(SimplifiedValues.lookup(Cond))) {
+          BBWorklist.insert(BI->getSuccessor(SimpleCond->isZero() ? 1 : 0));
+          continue;
+        }
+      }
+    } else if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) {
+      Value *Cond = SI->getCondition();
+      if (ConstantInt *SimpleCond
+            = dyn_cast_or_null<ConstantInt>(SimplifiedValues.lookup(Cond))) {
+        BBWorklist.insert(SI->findCaseValue(SimpleCond).getCaseSuccessor());
+        continue;
+      }
+    }
+
+    // If we're unable to select a particular successor, just count all of
+    // them.
+    for (unsigned TIdx = 0, TSize = TI->getNumSuccessors(); TIdx != TSize;
+         ++TIdx)
+      BBWorklist.insert(TI->getSuccessor(TIdx));
+
+    // If we had any successors at this point, than post-inlining is likely to
+    // have them as well. Note that we assume any basic blocks which existed
+    // due to branches or switches which folded above will also fold after
+    // inlining.
+    if (SingleBB && TI->getNumSuccessors() > 1) {
+      // Take off the bonus we applied to the threshold.
+      Threshold -= SingleBBBonus;
+      SingleBB = false;
+    }
+  }
+
+  // If this is a noduplicate call, we can still inline as long as
+  // inlining this would cause the removal of the caller (so the instruction
+  // is not actually duplicated, just moved).
+  if (!OnlyOneCallAndLocalLinkage && ContainsNoDuplicateCall)
+    return false;
+
+  // We applied the maximum possible vector bonus at the beginning. Now,
+  // subtract the excess bonus, if any, from the Threshold before
+  // comparing against Cost.
+  if (NumVectorInstructions <= NumInstructions / 10)
+    Threshold -= FiftyPercentVectorBonus;
+  else if (NumVectorInstructions <= NumInstructions / 2)
+    Threshold -= (FiftyPercentVectorBonus - TenPercentVectorBonus);
+
+  return Cost < Threshold;
+}
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+/// \brief Dump stats about this call's analysis.
+void CallAnalyzer::dump() {
+#define DEBUG_PRINT_STAT(x) dbgs() << "      " #x ": " << x << "\n"
+  DEBUG_PRINT_STAT(NumConstantArgs);
+  DEBUG_PRINT_STAT(NumConstantOffsetPtrArgs);
+  DEBUG_PRINT_STAT(NumAllocaArgs);
+  DEBUG_PRINT_STAT(NumConstantPtrCmps);
+  DEBUG_PRINT_STAT(NumConstantPtrDiffs);
+  DEBUG_PRINT_STAT(NumInstructionsSimplified);
+  DEBUG_PRINT_STAT(NumInstructions);
+  DEBUG_PRINT_STAT(SROACostSavings);
+  DEBUG_PRINT_STAT(SROACostSavingsLost);
+  DEBUG_PRINT_STAT(ContainsNoDuplicateCall);
+  DEBUG_PRINT_STAT(Cost);
+  DEBUG_PRINT_STAT(Threshold);
+#undef DEBUG_PRINT_STAT
+}
+#endif
+
+INITIALIZE_PASS_BEGIN(InlineCostAnalysis, "inline-cost", "Inline Cost Analysis",
+                      true, true)
+INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
+INITIALIZE_PASS_END(InlineCostAnalysis, "inline-cost", "Inline Cost Analysis",
+                    true, true)
+
+char InlineCostAnalysis::ID = 0;
+
+InlineCostAnalysis::InlineCostAnalysis() : CallGraphSCCPass(ID) {}
+
+InlineCostAnalysis::~InlineCostAnalysis() {}
+
+void InlineCostAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.setPreservesAll();
+  AU.addRequired<AssumptionCacheTracker>();
+  AU.addRequired<TargetTransformInfoWrapperPass>();
+  CallGraphSCCPass::getAnalysisUsage(AU);
+}
+
+bool InlineCostAnalysis::runOnSCC(CallGraphSCC &SCC) {
+  TTIWP = &getAnalysis<TargetTransformInfoWrapperPass>();
+  ACT = &getAnalysis<AssumptionCacheTracker>();
+  return false;
+}
+
+InlineCost InlineCostAnalysis::getInlineCost(CallSite CS, int Threshold) {
+  return getInlineCost(CS, CS.getCalledFunction(), Threshold);
+}
+
+/// \brief Test that two functions either have or have not the given attribute
+///        at the same time.
+template<typename AttrKind>
+static bool attributeMatches(Function *F1, Function *F2, AttrKind Attr) {
+  return F1->getFnAttribute(Attr) == F2->getFnAttribute(Attr);
+}
+
+/// \brief Test that there are no attribute conflicts between Caller and Callee
+///        that prevent inlining.
+static bool functionsHaveCompatibleAttributes(Function *Caller,
+                                              Function *Callee,
+                                              TargetTransformInfo &TTI) {
+  return TTI.areInlineCompatible(Caller, Callee) &&
+         attributeMatches(Caller, Callee, Attribute::SanitizeAddress) &&
+         attributeMatches(Caller, Callee, Attribute::SanitizeMemory) &&
+         attributeMatches(Caller, Callee, Attribute::SanitizeThread);
+}
+
+InlineCost InlineCostAnalysis::getInlineCost(CallSite CS, Function *Callee,
+                                             int Threshold) {
+  // Cannot inline indirect calls.
+  if (!Callee)
+    return llvm::InlineCost::getNever();
+
+  // Calls to functions with always-inline attributes should be inlined
+  // whenever possible.
+  if (CS.hasFnAttr(Attribute::AlwaysInline)) {
+    if (isInlineViable(*Callee))
+      return llvm::InlineCost::getAlways();
+    return llvm::InlineCost::getNever();
+  }
+
+  // Never inline functions with conflicting attributes (unless callee has
+  // always-inline attribute).
+  if (!functionsHaveCompatibleAttributes(CS.getCaller(), Callee,
+                                         TTIWP->getTTI(*Callee)))
+    return llvm::InlineCost::getNever();
+
+  // Don't inline this call if the caller has the optnone attribute.
+  if (CS.getCaller()->hasFnAttribute(Attribute::OptimizeNone))
+    return llvm::InlineCost::getNever();
+
+  // Don't inline functions which can be redefined at link-time to mean
+  // something else.  Don't inline functions marked noinline or call sites
+  // marked noinline.
+  if (Callee->mayBeOverridden() ||
+      Callee->hasFnAttribute(Attribute::NoInline) || CS.isNoInline())
+    return llvm::InlineCost::getNever();
+
+  DEBUG(llvm::dbgs() << "      Analyzing call of " << Callee->getName()
+        << "...\n");
+
+  CallAnalyzer CA(TTIWP->getTTI(*Callee), ACT, *Callee, Threshold, CS);
+  bool ShouldInline = CA.analyzeCall(CS);
+
+  DEBUG(CA.dump());
+
+  // Check if there was a reason to force inlining or no inlining.
+  if (!ShouldInline && CA.getCost() < CA.getThreshold())
+    return InlineCost::getNever();
+  if (ShouldInline && CA.getCost() >= CA.getThreshold())
+    return InlineCost::getAlways();
+
+  return llvm::InlineCost::get(CA.getCost(), CA.getThreshold());
+}
+
+bool InlineCostAnalysis::isInlineViable(Function &F) {
+  bool ReturnsTwice = F.hasFnAttribute(Attribute::ReturnsTwice);
+  for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE; ++BI) {
+    // Disallow inlining of functions which contain indirect branches or
+    // blockaddresses.
+    if (isa<IndirectBrInst>(BI->getTerminator()) || BI->hasAddressTaken())
+      return false;
+
+    for (BasicBlock::iterator II = BI->begin(), IE = BI->end(); II != IE;
+         ++II) {
+      CallSite CS(II);
+      if (!CS)
+        continue;
+
+      // Disallow recursive calls.
+      if (&F == CS.getCalledFunction())
+        return false;
+
+      // Disallow calls which expose returns-twice to a function not previously
+      // attributed as such.
+      if (!ReturnsTwice && CS.isCall() &&
+          cast<CallInst>(CS.getInstruction())->canReturnTwice())
+        return false;
+
+      // Disallow inlining functions that call @llvm.localescape. Doing this
+      // correctly would require major changes to the inliner.
+      if (CS.getCalledFunction() &&
+          CS.getCalledFunction()->getIntrinsicID() ==
+              llvm::Intrinsic::localescape)
+        return false;
+    }
+  }
+
+  return true;
+}

llvm/trunk/lib/Analysis/LLVMBuild.txt

 ; This is an LLVMBuild description file for the components in this subdirectory.
 ;
 ; For more information on the LLVMBuild system, please see:
 ;
 ;   http://llvm.org/docs/LLVMBuild.html
 ;
 ;===------------------------------------------------------------------------===;
 
-[common]
-subdirectories = IPA
-
 [component_0]
 type = Library
 name = Analysis
 parent = Libraries
 required_libraries = Core Support

llvm/trunk/lib/Analysis/Makefile

 ##===- lib/Analysis/Makefile -------------------------------*- Makefile -*-===##
 #
 #                     The LLVM Compiler Infrastructure
 #
 # This file is distributed under the University of Illinois Open Source
 # License. See LICENSE.TXT for details.
 #
 ##===----------------------------------------------------------------------===##
 
 LEVEL = ../..
 LIBRARYNAME = LLVMAnalysis
-DIRS = IPA
 BUILD_ARCHIVE = 1
 
 include $(LEVEL)/Makefile.common
 

llvm/trunk/lib/LTO/LLVMBuild.txt

 name = LTO
 parent = Libraries
 required_libraries =
  Analysis
  BitReader
  BitWriter
  CodeGen
  Core
- IPA
  IPO
  InstCombine
  Linker
  MC
  ObjCARC
  Object
  Scalar
  Support
  Target

llvm/trunk/lib/Passes/LLVMBuild.txt

 ;   http://llvm.org/docs/LLVMBuild.html
 ;
 ;===------------------------------------------------------------------------===;
 
 [component_0]
 type = Library
 name = Passes
 parent = Libraries
-required_libraries = Analysis Core IPA IPO InstCombine Scalar Support TransformUtils Vectorize
+required_libraries = Analysis Core IPO InstCombine Scalar Support TransformUtils Vectorize

llvm/trunk/lib/Transforms/IPO/LLVMBuild.txt

 ;
 ;===------------------------------------------------------------------------===;
 
 [component_0]
 type = Library
 name = IPO
 parent = Transforms
 library_name = ipo
-required_libraries = Analysis Core IPA InstCombine Scalar Support TransformUtils Vectorize
+required_libraries = Analysis Core InstCombine Scalar Support TransformUtils Vectorize

llvm/trunk/lib/Transforms/Utils/LLVMBuild.txt

 ;   http://llvm.org/docs/LLVMBuild.html
 ;
 ;===------------------------------------------------------------------------===;
 
 [component_0]
 type = Library
 name = TransformUtils
 parent = Transforms
-required_libraries = Analysis Core IPA Support
+required_libraries = Analysis Core Support

llvm/trunk/tools/bugpoint/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
   Analysis
   BitWriter
   CodeGen
   Core
-  IPA
   IPO
   IRReader
   InstCombine
   Instrumentation
   Linker
   ObjCARCOpts
   ScalarOpts
   Support

llvm/trunk/tools/bugpoint/bugpoint.cpp

#endif
   // Initialize passes
   PassRegistry &Registry = *PassRegistry::getPassRegistry();
   initializeCore(Registry);
   initializeScalarOpts(Registry);
   initializeObjCARCOpts(Registry);
   initializeVectorization(Registry);
   initializeIPO(Registry);
   initializeAnalysis(Registry);
-  initializeIPA(Registry);
   initializeTransformUtils(Registry);
   initializeInstCombine(Registry);
   initializeInstrumentation(Registry);
   initializeTarget(Registry);
 
 #ifdef LINK_POLLY_INTO_TOOLS
   polly::initializePollyPasses(Registry);
 #endif

llvm/trunk/tools/llvm-shlib/CMakeLists.txt

set(LLVM_DYLIB_COMPONENTS
     Analysis
     BitReader
     BitWriter
     CodeGen
     Core
     DebugInfoDWARF
     DebugInfoPDB
     ExecutionEngine
-    IPA
     IPO
     IRReader
     InstCombine
     Instrumentation
     Interpreter
     Linker
     MCDisassembler
     MCJIT

llvm/trunk/tools/llvm-stress/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
+  Analysis
   Core
-  IPA
   Support
   )
 
 add_llvm_tool(llvm-stress
   llvm-stress.cpp
   )
 export_executable_symbols(llvm-stress)

llvm/trunk/tools/opt/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
   ${LLVM_TARGETS_TO_BUILD}
   Analysis
   BitWriter
   CodeGen
   Core
-  IPA
   IPO
   IRReader
   InstCombine
   Instrumentation
   MC
   ObjCARCOpts
   ScalarOpts
   Support

llvm/trunk/tools/opt/opt.cpp

int main(int argc, char **argv) {
   // Initialize passes
   PassRegistry &Registry = *PassRegistry::getPassRegistry();
   initializeCore(Registry);
   initializeScalarOpts(Registry);
   initializeObjCARCOpts(Registry);
   initializeVectorization(Registry);
   initializeIPO(Registry);
   initializeAnalysis(Registry);
-  initializeIPA(Registry);
   initializeTransformUtils(Registry);
   initializeInstCombine(Registry);
   initializeInstrumentation(Registry);
   initializeTarget(Registry);
   // For codegen passes, only passes that do IR to IR transformation are
   // supported.
   initializeCodeGenPreparePass(Registry);
   initializeAtomicExpandPass(Registry);

llvm/trunk/unittests/Analysis/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
-  IPA
   Analysis
   AsmParser
   Core
   Support
   )
 
 add_llvm_unittest(AnalysisTests
   AliasAnalysisTest.cpp
   CallGraphTest.cpp
   CFGTest.cpp
   LazyCallGraphTest.cpp
   ScalarEvolutionTest.cpp
   MixedTBAATest.cpp
   ValueTrackingTest.cpp
   )

llvm/trunk/unittests/Analysis/Makefile

 ##===- unittests/Analysis/Makefile -------------------------*- Makefile -*-===##
 #
 #                     The LLVM Compiler Infrastructure
 #
 # This file is distributed under the University of Illinois Open Source
 # License. See LICENSE.TXT for details.
 #
 ##===----------------------------------------------------------------------===##
 
 LEVEL = ../..
 TESTNAME = Analysis
-LINK_COMPONENTS := ipa analysis asmparser
+LINK_COMPONENTS := analysis asmparser
 
 include $(LEVEL)/Makefile.config
 include $(LLVM_SRC_ROOT)/unittests/Makefile.unittest

llvm/trunk/unittests/IR/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
   Analysis
   AsmParser
   Core
-  IPA
   Support
   )
 
 set(IRSources
   AttributesTest.cpp
   ConstantRangeTest.cpp
   ConstantsTest.cpp
   DebugInfoTest.cpp

llvm/trunk/unittests/IR/Makefile

 ##===- unittests/IR/Makefile -------------------------------*- Makefile -*-===##
 #
 #                     The LLVM Compiler Infrastructure
 #
 # This file is distributed under the University of Illinois Open Source
 # License. See LICENSE.TXT for details.
 #
 ##===----------------------------------------------------------------------===##
 
 LEVEL = ../..
 TESTNAME = IR
-LINK_COMPONENTS := core ipa asmparser
+LINK_COMPONENTS := core analysis asmparser
 
 include $(LEVEL)/Makefile.config
 include $(LLVM_SRC_ROOT)/unittests/Makefile.unittest