[C++] Use 'nullptr'. Transforms edition.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207196 91177308-0d34-0410-b5e6-96231b3b80d8

18 files changed, 88 insertions, 86 deletions

diff --git a/lib/Transforms/IPO/ArgumentPromotion.cpp b/lib/Transforms/IPO/ArgumentPromotion.cpp
index 94b44654d9..377fa153a2 100644
--- a/lib/Transforms/IPO/ArgumentPromotion.cpp
+++ b/lib/Transforms/IPO/ArgumentPromotion.cpp
@@ -124,14 +124,14 @@ CallGraphNode *ArgPromotion::PromoteArguments(CallGraphNode *CGN) {
   Function *F = CGN->getFunction();
 
   // Make sure that it is local to this module.
-  if (!F || !F->hasLocalLinkage()) return 0;
+  if (!F || !F->hasLocalLinkage()) return nullptr;
 
   // First check: see if there are any pointer arguments!  If not, quick exit.
   SmallVector<Argument*, 16> PointerArgs;
   for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
     if (I->getType()->isPointerTy())
       PointerArgs.push_back(I);
-  if (PointerArgs.empty()) return 0;
+  if (PointerArgs.empty()) return nullptr;
 
   // Second check: make sure that all callers are direct callers.  We can't
   // transform functions that have indirect callers.  Also see if the function
@@ -140,7 +140,7 @@ CallGraphNode *ArgPromotion::PromoteArguments(CallGraphNode *CGN) {
   for (Use &U : F->uses()) {
     CallSite CS(U.getUser());
     // Must be a direct call.
-    if (CS.getInstruction() == 0 || !CS.isCallee(&U)) return 0;
+    if (CS.getInstruction() == nullptr || !CS.isCallee(&U)) return nullptr;
     
     if (CS.getInstruction()->getParent()->getParent() == F)
       isSelfRecursive = true;
@@ -208,7 +208,7 @@ CallGraphNode *ArgPromotion::PromoteArguments(CallGraphNode *CGN) {
 
   // No promotable pointer arguments.
   if (ArgsToPromote.empty() && ByValArgsToTransform.empty()) 
-    return 0;
+    return nullptr;
 
   return DoPromotion(F, ArgsToPromote, ByValArgsToTransform);
 }
@@ -661,7 +661,7 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
         Type *AgTy = cast<PointerType>(I->getType())->getElementType();
         StructType *STy = cast<StructType>(AgTy);
         Value *Idxs[2] = {
-              ConstantInt::get(Type::getInt32Ty(F->getContext()), 0), 0 };
+              ConstantInt::get(Type::getInt32Ty(F->getContext()), 0), nullptr };
         for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
           Idxs[1] = ConstantInt::get(Type::getInt32Ty(F->getContext()), i);
           Value *Idx = GetElementPtrInst::Create(*AI, Idxs,
@@ -789,10 +789,10 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
 
       // Just add all the struct element types.
       Type *AgTy = cast<PointerType>(I->getType())->getElementType();
-      Value *TheAlloca = new AllocaInst(AgTy, 0, "", InsertPt);
+      Value *TheAlloca = new AllocaInst(AgTy, nullptr, "", InsertPt);
       StructType *STy = cast<StructType>(AgTy);
       Value *Idxs[2] = {
-            ConstantInt::get(Type::getInt32Ty(F->getContext()), 0), 0 };
+            ConstantInt::get(Type::getInt32Ty(F->getContext()), 0), nullptr };
 
       for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
         Idxs[1] = ConstantInt::get(Type::getInt32Ty(F->getContext()), i);
diff --git a/lib/Transforms/IPO/ConstantMerge.cpp b/lib/Transforms/IPO/ConstantMerge.cpp
index badac5b2d8..23be0819e6 100644
--- a/lib/Transforms/IPO/ConstantMerge.cpp
+++ b/lib/Transforms/IPO/ConstantMerge.cpp
@@ -67,7 +67,7 @@ ModulePass *llvm::createConstantMergePass() { return new ConstantMerge(); }
 /// Find values that are marked as llvm.used.
 static void FindUsedValues(GlobalVariable *LLVMUsed,
                            SmallPtrSet<const GlobalValue*, 8> &UsedValues) {
-  if (LLVMUsed == 0) return;
+  if (!LLVMUsed) return;
   ConstantArray *Inits = cast<ConstantArray>(LLVMUsed->getInitializer());
 
   for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i) {
@@ -104,7 +104,7 @@ unsigned ConstantMerge::getAlignment(GlobalVariable *GV) const {
 
 bool ConstantMerge::runOnModule(Module &M) {
   DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
-  DL = DLP ? &DLP->getDataLayout() : 0;
+  DL = DLP ? &DLP->getDataLayout() : nullptr;
 
   // Find all the globals that are marked "used".  These cannot be merged.
   SmallPtrSet<const GlobalValue*, 8> UsedGlobals;
@@ -162,7 +162,7 @@ bool ConstantMerge::runOnModule(Module &M) {
       // If this is the first constant we find or if the old one is local,
       // replace with the current one. If the current is externally visible
       // it cannot be replace, but can be the canonical constant we merge with.
-      if (Slot == 0 || IsBetterCanonical(*GV, *Slot))
+      if (!Slot || IsBetterCanonical(*GV, *Slot))
         Slot = GV;
     }
 
diff --git a/lib/Transforms/IPO/DeadArgumentElimination.cpp b/lib/Transforms/IPO/DeadArgumentElimination.cpp
index 4a3a0cd729..d0a42664a6 100644
--- a/lib/Transforms/IPO/DeadArgumentElimination.cpp
+++ b/lib/Transforms/IPO/DeadArgumentElimination.cpp
@@ -765,7 +765,7 @@ bool DAE::RemoveDeadStuffFromFunction(Function *F) {
 
   // Find out the new return value.
   Type *RetTy = FTy->getReturnType();
-  Type *NRetTy = NULL;
+  Type *NRetTy = nullptr;
   unsigned RetCount = NumRetVals(F);
 
   // -1 means unused, other numbers are the new index
@@ -1051,7 +1051,7 @@ bool DAE::RemoveDeadStuffFromFunction(Function *F) {
         Value *RetVal;
 
         if (NFTy->getReturnType()->isVoidTy()) {
-          RetVal = 0;
+          RetVal = nullptr;
         } else {
           assert (RetTy->isStructTy());
           // The original return value was a struct, insert
diff --git a/lib/Transforms/IPO/ExtractGV.cpp b/lib/Transforms/IPO/ExtractGV.cpp
index 4211f12238..408713a2c2 100644
--- a/lib/Transforms/IPO/ExtractGV.cpp
+++ b/lib/Transforms/IPO/ExtractGV.cpp
@@ -95,7 +95,7 @@ namespace {
 	makeVisible(*I, Delete);
 
         if (Delete)
-          I->setInitializer(0);
+          I->setInitializer(nullptr);
       }
 
       // Visit the Functions.
@@ -134,7 +134,7 @@ namespace {
           } else {
             Declaration =
               new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage,
-                                 0, CurI->getName());
+                                 nullptr, CurI->getName());
 
           }
           CurI->replaceAllUsesWith(Declaration);
diff --git a/lib/Transforms/IPO/FunctionAttrs.cpp b/lib/Transforms/IPO/FunctionAttrs.cpp
index ba6182daf3..1819fe1f82 100644
--- a/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -47,7 +47,7 @@ STATISTIC(NumAnnotated, "Number of attributes added to library functions");
 namespace {
   struct FunctionAttrs : public CallGraphSCCPass {
     static char ID; // Pass identification, replacement for typeid
-    FunctionAttrs() : CallGraphSCCPass(ID), AA(0) {
+    FunctionAttrs() : CallGraphSCCPass(ID), AA(nullptr) {
       initializeFunctionAttrsPass(*PassRegistry::getPassRegistry());
     }
 
@@ -161,7 +161,7 @@ bool FunctionAttrs::AddReadAttrs(const CallGraphSCC &SCC) {
   for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
     Function *F = (*I)->getFunction();
 
-    if (F == 0)
+    if (!F)
       // External node - may write memory.  Just give up.
       return false;
 
@@ -320,7 +320,7 @@ namespace {
     ArgumentGraphNode SyntheticRoot;
 
   public:
-    ArgumentGraph() { SyntheticRoot.Definition = 0; }
+    ArgumentGraph() { SyntheticRoot.Definition = nullptr; }
 
     typedef SmallVectorImpl<ArgumentGraphNode*>::iterator iterator;
 
@@ -522,7 +522,7 @@ bool FunctionAttrs::AddArgumentAttrs(const CallGraphSCC &SCC) {
   for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
     Function *F = (*I)->getFunction();
 
-    if (F == 0)
+    if (!F)
       // External node - only a problem for arguments that we pass to it.
       continue;
 
@@ -776,7 +776,7 @@ bool FunctionAttrs::AddNoAliasAttrs(const CallGraphSCC &SCC) {
   for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
     Function *F = (*I)->getFunction();
 
-    if (F == 0)
+    if (!F)
       // External node - skip it;
       return false;
 
@@ -1669,7 +1669,7 @@ bool FunctionAttrs::annotateLibraryCalls(const CallGraphSCC &SCC) {
   for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
     Function *F = (*I)->getFunction();
 
-    if (F != 0 && F->isDeclaration())
+    if (F && F->isDeclaration())
       MadeChange |= inferPrototypeAttributes(*F);
   }
 
diff --git a/lib/Transforms/IPO/GlobalDCE.cpp b/lib/Transforms/IPO/GlobalDCE.cpp
index 37910d179a..0cf03a54c2 100644
--- a/lib/Transforms/IPO/GlobalDCE.cpp
+++ b/lib/Transforms/IPO/GlobalDCE.cpp
@@ -100,7 +100,7 @@ bool GlobalDCE::runOnModule(Module &M) {
        I != E; ++I)
     if (!AliveGlobals.count(I)) {
       DeadGlobalVars.push_back(I);         // Keep track of dead globals
-      I->setInitializer(0);
+      I->setInitializer(nullptr);
     }
 
   // The second pass drops the bodies of functions which are dead...
@@ -118,7 +118,7 @@ bool GlobalDCE::runOnModule(Module &M) {
        ++I)
     if (!AliveGlobals.count(I)) {
       DeadAliases.push_back(I);
-      I->setAliasee(0);
+      I->setAliasee(nullptr);
     }
 
   if (!DeadFunctions.empty()) {
diff --git a/lib/Transforms/IPO/GlobalOpt.cpp b/lib/Transforms/IPO/GlobalOpt.cpp
index 3846339b18..cc7e2abd80 100644
--- a/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/lib/Transforms/IPO/GlobalOpt.cpp
@@ -295,7 +295,7 @@ static bool CleanupConstantGlobalUsers(Value *V, Constant *Init,
       Changed = true;
     } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(U)) {
       if (CE->getOpcode() == Instruction::GetElementPtr) {
-        Constant *SubInit = 0;
+        Constant *SubInit = nullptr;
         if (Init)
           SubInit = ConstantFoldLoadThroughGEPConstantExpr(Init, CE);
         Changed |= CleanupConstantGlobalUsers(CE, SubInit, DL, TLI);
@@ -303,7 +303,7 @@ static bool CleanupConstantGlobalUsers(Value *V, Constant *Init,
                   CE->getType()->isPointerTy()) ||
                  CE->getOpcode() == Instruction::AddrSpaceCast) {
         // Pointer cast, delete any stores and memsets to the global.
-        Changed |= CleanupConstantGlobalUsers(CE, 0, DL, TLI);
+        Changed |= CleanupConstantGlobalUsers(CE, nullptr, DL, TLI);
       }
 
       if (CE->use_empty()) {
@@ -314,7 +314,7 @@ static bool CleanupConstantGlobalUsers(Value *V, Constant *Init,
       // Do not transform "gepinst (gep constexpr (GV))" here, because forming
       // "gepconstexpr (gep constexpr (GV))" will cause the two gep's to fold
       // and will invalidate our notion of what Init is.
-      Constant *SubInit = 0;
+      Constant *SubInit = nullptr;
       if (!isa<ConstantExpr>(GEP->getOperand(0))) {
         ConstantExpr *CE =
           dyn_cast_or_null<ConstantExpr>(ConstantFoldInstruction(GEP, DL, TLI));
@@ -371,7 +371,7 @@ static bool isSafeSROAElementUse(Value *V) {
 
   // Otherwise, it must be a GEP.
   GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(I);
-  if (GEPI == 0) return false;
+  if (!GEPI) return false;
 
   if (GEPI->getNumOperands() < 3 || !isa<Constant>(GEPI->getOperand(1)) ||
       !cast<Constant>(GEPI->getOperand(1))->isNullValue())
@@ -471,7 +471,7 @@ static bool GlobalUsersSafeToSRA(GlobalValue *GV) {
 static GlobalVariable *SRAGlobal(GlobalVariable *GV, const DataLayout &DL) {
   // Make sure this global only has simple uses that we can SRA.
   if (!GlobalUsersSafeToSRA(GV))
-    return 0;
+    return nullptr;
 
   assert(GV->hasLocalLinkage() && !GV->isConstant());
   Constant *Init = GV->getInitializer();
@@ -515,7 +515,7 @@ static GlobalVariable *SRAGlobal(GlobalVariable *GV, const DataLayout &DL) {
       NumElements = cast<VectorType>(STy)->getNumElements();
 
     if (NumElements > 16 && GV->hasNUsesOrMore(16))
-      return 0; // It's not worth it.
+      return nullptr; // It's not worth it.
     NewGlobals.reserve(NumElements);
 
     uint64_t EltSize = DL.getTypeAllocSize(STy->getElementType());
@@ -542,7 +542,7 @@ static GlobalVariable *SRAGlobal(GlobalVariable *GV, const DataLayout &DL) {
   }
 
   if (NewGlobals.empty())
-    return 0;
+    return nullptr;
 
   DEBUG(dbgs() << "PERFORMING GLOBAL SRA ON: " << *GV);
 
@@ -604,7 +604,7 @@ static GlobalVariable *SRAGlobal(GlobalVariable *GV, const DataLayout &DL) {
       if (FirstGlobal == i) ++FirstGlobal;
     }
 
-  return FirstGlobal != NewGlobals.size() ? NewGlobals[FirstGlobal] : 0;
+  return FirstGlobal != NewGlobals.size() ? NewGlobals[FirstGlobal] : nullptr;
 }
 
 /// AllUsesOfValueWillTrapIfNull - Return true if all users of the specified
@@ -786,7 +786,7 @@ static bool OptimizeAwayTrappingUsesOfLoads(GlobalVariable *GV, Constant *LV,
       Changed |= CleanupPointerRootUsers(GV, TLI);
     } else {
       Changed = true;
-      CleanupConstantGlobalUsers(GV, 0, DL, TLI);
+      CleanupConstantGlobalUsers(GV, nullptr, DL, TLI);
     }
     if (GV->use_empty()) {
       DEBUG(dbgs() << "  *** GLOBAL NOW DEAD!\n");
@@ -848,7 +848,7 @@ static GlobalVariable *OptimizeGlobalAddressOfMalloc(GlobalVariable *GV,
   // If there are bitcast users of the malloc (which is typical, usually we have
   // a malloc + bitcast) then replace them with uses of the new global.  Update
   // other users to use the global as well.
-  BitCastInst *TheBC = 0;
+  BitCastInst *TheBC = nullptr;
   while (!CI->use_empty()) {
     Instruction *User = cast<Instruction>(CI->user_back());
     if (BitCastInst *BCI = dyn_cast<BitCastInst>(User)) {
@@ -859,7 +859,7 @@ static GlobalVariable *OptimizeGlobalAddressOfMalloc(GlobalVariable *GV,
         BCI->setOperand(0, NewGV);
       }
     } else {
-      if (TheBC == 0)
+      if (!TheBC)
         TheBC = new BitCastInst(NewGV, CI->getType(), "newgv", CI);
       User->replaceUsesOfWith(CI, TheBC);
     }
@@ -1307,7 +1307,7 @@ static GlobalVariable *PerformHeapAllocSRoA(GlobalVariable *GV, CallInst *CI,
     Type *IntPtrTy = DL->getIntPtrType(CI->getType());
     Value *NMI = CallInst::CreateMalloc(CI, IntPtrTy, FieldTy,
                                         ConstantInt::get(IntPtrTy, TypeSize),
-                                        NElems, 0,
+                                        NElems, nullptr,
                                         CI->getName() + ".f" + Twine(FieldNo));
     FieldMallocs.push_back(NMI);
     new StoreInst(NMI, NGV, CI);
@@ -1540,7 +1540,7 @@ static bool TryToOptimizeStoreOfMallocToGlobal(GlobalVariable *GV,
       Value *NumElements = ConstantInt::get(IntPtrTy, AT->getNumElements());
       Instruction *Malloc = CallInst::CreateMalloc(CI, IntPtrTy, AllocSTy,
                                                    AllocSize, NumElements,
-                                                   0, CI->getName());
+                                                   nullptr, CI->getName());
       Instruction *Cast = new BitCastInst(Malloc, CI->getType(), "tmp", CI);
       CI->replaceAllUsesWith(Cast);
       CI->eraseFromParent();
@@ -1755,7 +1755,8 @@ bool GlobalOpt::ProcessInternalGlobal(GlobalVariable *GV,
                                                    ->getEntryBlock().begin());
     Type *ElemTy = GV->getType()->getElementType();
     // FIXME: Pass Global's alignment when globals have alignment
-    AllocaInst *Alloca = new AllocaInst(ElemTy, NULL, GV->getName(), &FirstI);
+    AllocaInst *Alloca = new AllocaInst(ElemTy, nullptr,
+                                        GV->getName(), &FirstI);
     if (!isa<UndefValue>(GV->getInitializer()))
       new StoreInst(GV->getInitializer(), Alloca, &FirstI);
 
@@ -1966,11 +1967,11 @@ bool GlobalOpt::OptimizeGlobalVars(Module &M) {
 /// initializers have an init priority of 65535.
 GlobalVariable *GlobalOpt::FindGlobalCtors(Module &M) {
   GlobalVariable *GV = M.getGlobalVariable("llvm.global_ctors");
-  if (GV == 0) return 0;
+  if (!GV) return nullptr;
 
   // Verify that the initializer is simple enough for us to handle. We are
   // only allowed to optimize the initializer if it is unique.
-  if (!GV->hasUniqueInitializer()) return 0;
+  if (!GV->hasUniqueInitializer()) return nullptr;
 
   if (isa<ConstantAggregateZero>(GV->getInitializer()))
     return GV;
@@ -1985,12 +1986,12 @@ GlobalVariable *GlobalOpt::FindGlobalCtors(Module &M) {
 
     // Must have a function or null ptr.
     if (!isa<Function>(CS->getOperand(1)))
-      return 0;
+      return nullptr;
 
     // Init priority must be standard.
     ConstantInt *CI = cast<ConstantInt>(CS->getOperand(0));
     if (CI->getZExtValue() != 65535)
-      return 0;
+      return nullptr;
   }
 
   return GV;
@@ -2018,7 +2019,7 @@ static GlobalVariable *InstallGlobalCtors(GlobalVariable *GCL,
   // If we made a change, reassemble the initializer list.
   Constant *CSVals[2];
   CSVals[0] = ConstantInt::get(Type::getInt32Ty(GCL->getContext()), 65535);
-  CSVals[1] = 0;
+  CSVals[1] = nullptr;
 
   StructType *StructTy =
     cast<StructType>(GCL->getType()->getElementType()->getArrayElementType());
@@ -2068,7 +2069,7 @@ static GlobalVariable *InstallGlobalCtors(GlobalVariable *GCL,
   if (Ctors.size())
     return NGV;
   else
-    return 0;
+    return nullptr;
 }
 
 
@@ -2368,7 +2369,7 @@ Constant *Evaluator::ComputeLoadResult(Constant *P) {
   if (GlobalVariable *GV = dyn_cast<GlobalVariable>(P)) {
     if (GV->hasDefinitiveInitializer())
       return GV->getInitializer();
-    return 0;
+    return nullptr;
   }
 
   // Handle a constantexpr getelementptr.
@@ -2380,7 +2381,7 @@ Constant *Evaluator::ComputeLoadResult(Constant *P) {
         return ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE);
     }
 
-  return 0;  // don't know how to evaluate.
+  return nullptr;  // don't know how to evaluate.
 }
 
 /// EvaluateBlock - Evaluate all instructions in block BB, returning true if
@@ -2390,7 +2391,7 @@ bool Evaluator::EvaluateBlock(BasicBlock::iterator CurInst,
                               BasicBlock *&NextBB) {
   // This is the main evaluation loop.
   while (1) {
-    Constant *InstResult = 0;
+    Constant *InstResult = nullptr;
 
     DEBUG(dbgs() << "Evaluating Instruction: " << *CurInst << "\n");
 
@@ -2516,7 +2517,7 @@ bool Evaluator::EvaluateBlock(BasicBlock::iterator CurInst,
               "folding: " << *Ptr << "\n");
       }
       InstResult = ComputeLoadResult(Ptr);
-      if (InstResult == 0) {
+      if (!InstResult) {
         DEBUG(dbgs() << "Failed to compute load result. Can not evaluate load."
               "\n");
         return false; // Could not evaluate load.
@@ -2634,7 +2635,7 @@ bool Evaluator::EvaluateBlock(BasicBlock::iterator CurInst,
           return false;
         }
 
-        Constant *RetVal = 0;
+        Constant *RetVal = nullptr;
         // Execute the call, if successful, use the return value.
         ValueStack.push_back(make_unique<DenseMap<Value *, Constant *>>());
         if (!EvaluateFunction(Callee, RetVal, Formals)) {
@@ -2644,7 +2645,7 @@ bool Evaluator::EvaluateBlock(BasicBlock::iterator CurInst,
         ValueStack.pop_back();
         InstResult = RetVal;
 
-        if (InstResult != NULL) {
+        if (InstResult) {
           DEBUG(dbgs() << "Successfully evaluated function. Result: " <<
                 InstResult << "\n\n");
         } else {
@@ -2676,7 +2677,7 @@ bool Evaluator::EvaluateBlock(BasicBlock::iterator CurInst,
         else
           return false;  // Cannot determine.
       } else if (isa<ReturnInst>(CurInst)) {
-        NextBB = 0;
+        NextBB = nullptr;
       } else {
         // invoke, unwind, resume, unreachable.
         DEBUG(dbgs() << "Can not handle terminator.");
@@ -2741,13 +2742,13 @@ bool Evaluator::EvaluateFunction(Function *F, Constant *&RetVal,
   BasicBlock::iterator CurInst = CurBB->begin();
 
   while (1) {
-    BasicBlock *NextBB = 0; // Initialized to avoid compiler warnings.
+    BasicBlock *NextBB = nullptr; // Initialized to avoid compiler warnings.
     DEBUG(dbgs() << "Trying to evaluate BB: " << *CurBB << "\n");
 
     if (!EvaluateBlock(CurInst, NextBB))
       return false;
 
-    if (NextBB == 0) {
+    if (!NextBB) {
       // Successfully running until there's no next block means that we found
       // the return.  Fill it the return value and pop the call stack.
       ReturnInst *RI = cast<ReturnInst>(CurBB->getTerminator());
@@ -2766,7 +2767,7 @@ bool Evaluator::EvaluateFunction(Function *F, Constant *&RetVal,
     // Okay, we have never been in this block before.  Check to see if there
     // are any PHI nodes.  If so, evaluate them with information about where
     // we came from.
-    PHINode *PN = 0;
+    PHINode *PN = nullptr;
     for (CurInst = NextBB->begin();
          (PN = dyn_cast<PHINode>(CurInst)); ++CurInst)
       setVal(PN, getVal(PN->getIncomingValueForBlock(CurBB)));
@@ -2816,7 +2817,7 @@ bool GlobalOpt::OptimizeGlobalCtorsList(GlobalVariable *&GCL) {
     Function *F = Ctors[i];
     // Found a null terminator in the middle of the list, prune off the rest of
     // the list.
-    if (F == 0) {
+    if (!F) {
       if (i != Ctors.size()-1) {
         Ctors.resize(i+1);
         MadeChange = true;
@@ -3040,12 +3041,12 @@ bool GlobalOpt::OptimizeGlobalAliases(Module &M) {
 
 static Function *FindCXAAtExit(Module &M, TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc::cxa_atexit))
-    return 0;
+    return nullptr;
 
   Function *Fn = M.getFunction(TLI->getName(LibFunc::cxa_atexit));
 
   if (!Fn)
-    return 0;
+    return nullptr;
 
   FunctionType *FTy = Fn->getFunctionType();
 
@@ -3056,7 +3057,7 @@ static Function *FindCXAAtExit(Module &M, TargetLibraryInfo *TLI) {
       !FTy->getParamType(0)->isPointerTy() ||
       !FTy->getParamType(1)->isPointerTy() ||
       !FTy->getParamType(2)->isPointerTy())
-    return 0;
+    return nullptr;
 
   return Fn;
 }
@@ -3158,7 +3159,7 @@ bool GlobalOpt::runOnModule(Module &M) {
   bool Changed = false;
 
   DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
-  DL = DLP ? &DLP->getDataLayout() : 0;
+  DL = DLP ? &DLP->getDataLayout() : nullptr;
   TLI = &getAnalysis<TargetLibraryInfo>();
 
   // Try to find the llvm.globalctors list.
diff --git a/lib/Transforms/IPO/IPConstantPropagation.cpp b/lib/Transforms/IPO/IPConstantPropagation.cpp
index aaaab5e45c..af541d1552 100644
--- a/lib/Transforms/IPO/IPConstantPropagation.cpp
+++ b/lib/Transforms/IPO/IPConstantPropagation.cpp
@@ -113,7 +113,7 @@ bool IPCP::PropagateConstantsIntoArguments(Function &F) {
         continue;
       
       Constant *C = dyn_cast<Constant>(*AI);
-      if (C && ArgumentConstants[i].first == 0) {
+      if (C && ArgumentConstants[i].first == nullptr) {
         ArgumentConstants[i].first = C;   // First constant seen.
       } else if (C && ArgumentConstants[i].first == C) {
         // Still the constant value we think it is.
@@ -140,7 +140,7 @@ bool IPCP::PropagateConstantsIntoArguments(Function &F) {
       continue;
   
     Value *V = ArgumentConstants[i].first;
-    if (V == 0) V = UndefValue::get(AI->getType());
+    if (!V) V = UndefValue::get(AI->getType());
     AI->replaceAllUsesWith(V);
     ++NumArgumentsProped;
     MadeChange = true;
@@ -210,7 +210,7 @@ bool IPCP::PropagateConstantReturn(Function &F) {
         }
         // Different or no known return value? Don't propagate this return
         // value.
-        RetVals[i] = 0;
+        RetVals[i] = nullptr;
         // All values non-constant? Stop looking.
         if (++NumNonConstant == RetVals.size())
           return false;
@@ -236,7 +236,7 @@ bool IPCP::PropagateConstantReturn(Function &F) {
 
     MadeChange = true;
 
-    if (STy == 0) {
+    if (!STy) {
       Value* New = RetVals[0];
       if (Argument *A = dyn_cast<Argument>(New))
         // Was an argument returned? Then find the corresponding argument in
diff --git a/lib/Transforms/IPO/InlineAlways.cpp b/lib/Transforms/IPO/InlineAlways.cpp
index 73416722be..c5d9546cce 100644
--- a/lib/Transforms/IPO/InlineAlways.cpp
+++ b/lib/Transforms/IPO/InlineAlways.cpp
@@ -37,12 +37,13 @@ class AlwaysInliner : public Inliner {
 
 public:
   // Use extremely low threshold.
-  AlwaysInliner() : Inliner(ID, -2000000000, /*InsertLifetime*/ true), ICA(0) {
+  AlwaysInliner() : Inliner(ID, -2000000000, /*InsertLifetime*/ true),
+                    ICA(nullptr) {
     initializeAlwaysInlinerPass(*PassRegistry::getPassRegistry());
   }
 
   AlwaysInliner(bool InsertLifetime)
-      : Inliner(ID, -2000000000, InsertLifetime), ICA(0) {
+      : Inliner(ID, -2000000000, InsertLifetime), ICA(nullptr) {
     initializeAlwaysInlinerPass(*PassRegistry::getPassRegistry());
   }
 
diff --git a/lib/Transforms/IPO/InlineSimple.cpp b/lib/Transforms/IPO/InlineSimple.cpp
index 27c9f52f9e..d189756032 100644
--- a/lib/Transforms/IPO/InlineSimple.cpp
+++ b/lib/Transforms/IPO/InlineSimple.cpp
@@ -38,12 +38,12 @@ class SimpleInliner : public Inliner {
   InlineCostAnalysis *ICA;
 
 public:
-  SimpleInliner() : Inliner(ID), ICA(0) {
+  SimpleInliner() : Inliner(ID), ICA(nullptr) {
     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
   }
 
   SimpleInliner(int Threshold)
-      : Inliner(ID, Threshold, /*InsertLifetime*/ true), ICA(0) {
+      : Inliner(ID, Threshold, /*InsertLifetime*/ true), ICA(nullptr) {
     initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
   }
 
diff --git a/lib/Transforms/IPO/Inliner.cpp b/lib/Transforms/IPO/Inliner.cpp
index 03b5e4e5e8..e6748c4698 100644
--- a/lib/Transforms/IPO/Inliner.cpp
+++ b/lib/Transforms/IPO/Inliner.cpp
@@ -185,7 +185,7 @@ static bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI,
     // canonicalized to be an allocation *of* an array), or allocations whose
     // type is not itself an array (because we're afraid of pessimizing SRoA).
     ArrayType *ATy = dyn_cast<ArrayType>(AI->getAllocatedType());
-    if (ATy == 0 || AI->isArrayAllocation())
+    if (!ATy || AI->isArrayAllocation())
       continue;
     
     // Get the list of all available allocas for this array type.
@@ -241,7 +241,7 @@ static bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI,
       AI->eraseFromParent();
       MergedAwayAlloca = true;
       ++NumMergedAllocas;
-      IFI.StaticAllocas[AllocaNo] = 0;
+      IFI.StaticAllocas[AllocaNo] = nullptr;
       break;
     }
 
@@ -412,7 +412,7 @@ static bool InlineHistoryIncludes(Function *F, int InlineHistoryID,
 bool Inliner::runOnSCC(CallGraphSCC &SCC) {
   CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
   DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
-  const DataLayout *DL = DLP ? &DLP->getDataLayout() : 0;
+  const DataLayout *DL = DLP ? &DLP->getDataLayout() : nullptr;
   const TargetLibraryInfo *TLI = getAnalysisIfAvailable<TargetLibraryInfo>();
 
   SmallPtrSet<Function*, 8> SCCFunctions;
@@ -501,7 +501,7 @@ bool Inliner::runOnSCC(CallGraphSCC &SCC) {
         ++NumCallsDeleted;
       } else {
         // We can only inline direct calls to non-declarations.
-        if (Callee == 0 || Callee->isDeclaration()) continue;
+        if (!Callee || Callee->isDeclaration()) continue;
       
         // If this call site was obtained by inlining another function, verify
         // that the include path for the function did not include the callee
diff --git a/lib/Transforms/IPO/Internalize.cpp b/lib/Transforms/IPO/Internalize.cpp
index 2ca0bdbdb8..cdb85fd525 100644
--- a/lib/Transforms/IPO/Internalize.cpp
+++ b/lib/Transforms/IPO/Internalize.cpp
@@ -132,8 +132,8 @@ static bool shouldInternalize(const GlobalValue &GV,
 
 bool InternalizePass::runOnModule(Module &M) {
   CallGraphWrapperPass *CGPass = getAnalysisIfAvailable<CallGraphWrapperPass>();
-  CallGraph *CG = CGPass ? &CGPass->getCallGraph() : 0;
-  CallGraphNode *ExternalNode = CG ? CG->getExternalCallingNode() : 0;
+  CallGraph *CG = CGPass ? &CGPass->getCallGraph() : nullptr;
+  CallGraphNode *ExternalNode = CG ? CG->getExternalCallingNode() : nullptr;
   bool Changed = false;
 
   SmallPtrSet<GlobalValue *, 8> Used;
diff --git a/lib/Transforms/IPO/LoopExtractor.cpp b/lib/Transforms/IPO/LoopExtractor.cpp
index c55fabceac..20414aa05b 100644
--- a/lib/Transforms/IPO/LoopExtractor.cpp
+++ b/lib/Transforms/IPO/LoopExtractor.cpp
@@ -137,7 +137,7 @@ bool LoopExtractor::runOnLoop(Loop *L, LPPassManager &LPM) {
     if (NumLoops == 0) return Changed;
     --NumLoops;
     CodeExtractor Extractor(DT, *L);
-    if (Extractor.extractCodeRegion() != 0) {
+    if (Extractor.extractCodeRegion() != nullptr) {
       Changed = true;
       // After extraction, the loop is replaced by a function call, so
       // we shouldn't try to run any more loop passes on it.
@@ -242,7 +242,7 @@ void BlockExtractorPass::SplitLandingPadPreds(Function *F) {
     if (!Split) continue;
 
     SmallVector<BasicBlock*, 2> NewBBs;
-    SplitLandingPadPredecessors(LPad, Parent, ".1", ".2", 0, NewBBs);
+    SplitLandingPadPredecessors(LPad, Parent, ".1", ".2", nullptr, NewBBs);
   }
 }
 
diff --git a/lib/Transforms/IPO/MergeFunctions.cpp b/lib/Transforms/IPO/MergeFunctions.cpp
index 3471d8f1f3..a1764ca33c 100644
--- a/lib/Transforms/IPO/MergeFunctions.cpp
+++ b/lib/Transforms/IPO/MergeFunctions.cpp
@@ -121,12 +121,12 @@ public:
   void release() {
     assert(Func &&
            "Attempted to release function twice, or release empty/tombstone!");
-    Func = NULL;
+    Func = nullptr;
   }
 
 private:
   explicit ComparableFunction(unsigned Hash)
-    : Func(NULL), Hash(Hash), DL(NULL) {}
+    : Func(nullptr), Hash(Hash), DL(nullptr) {}
 
   AssertingVH<Function> Func;
   unsigned Hash;
@@ -684,7 +684,7 @@ ModulePass *llvm::createMergeFunctionsPass() {
 bool MergeFunctions::runOnModule(Module &M) {
   bool Changed = false;
   DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
-  DL = DLP ? &DLP->getDataLayout() : 0;
+  DL = DLP ? &DLP->getDataLayout() : nullptr;
 
   for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
     if (!I->isDeclaration() && !I->hasAvailableExternallyLinkage())
diff --git a/lib/Transforms/IPO/PartialInlining.cpp b/lib/Transforms/IPO/PartialInlining.cpp
index f35f491b7f..76d6dfa8e8 100644
--- a/lib/Transforms/IPO/PartialInlining.cpp
+++ b/lib/Transforms/IPO/PartialInlining.cpp
@@ -53,10 +53,10 @@ Function* PartialInliner::unswitchFunction(Function* F) {
   BasicBlock* entryBlock = F->begin();
   BranchInst *BR = dyn_cast<BranchInst>(entryBlock->getTerminator());
   if (!BR || BR->isUnconditional())
-    return 0;
+    return nullptr;
   
-  BasicBlock* returnBlock = 0;
-  BasicBlock* nonReturnBlock = 0;
+  BasicBlock* returnBlock = nullptr;
+  BasicBlock* nonReturnBlock = nullptr;
   unsigned returnCount = 0;
   for (succ_iterator SI = succ_begin(entryBlock), SE = succ_end(entryBlock);
        SI != SE; ++SI)
@@ -67,7 +67,7 @@ Function* PartialInliner::unswitchFunction(Function* F) {
       nonReturnBlock = *SI;
   
   if (returnCount != 1)
-    return 0;
+    return nullptr;
   
   // Clone the function, so that we can hack away on it.
   ValueToValueMapTy VMap;
diff --git a/lib/Transforms/IPO/PassManagerBuilder.cpp b/lib/Transforms/IPO/PassManagerBuilder.cpp
index 052d24f58a..01ab31deca 100644
--- a/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -56,8 +56,8 @@ RunLoopRerolling("reroll-loops", cl::Hidden,
 PassManagerBuilder::PassManagerBuilder() {
     OptLevel = 2;
     SizeLevel = 0;
-    LibraryInfo = 0;
-    Inliner = 0;
+    LibraryInfo = nullptr;
+    Inliner = nullptr;
     DisableTailCalls = false;
     DisableUnitAtATime = false;
     DisableUnrollLoops = false;
@@ -129,7 +129,7 @@ void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
   if (OptLevel == 0) {
     if (Inliner) {
       MPM.add(Inliner);
-      Inliner = 0;
+      Inliner = nullptr;
     }
 
     // FIXME: This is a HACK! The inliner pass above implicitly creates a CGSCC
@@ -165,7 +165,7 @@ void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
     MPM.add(createPruneEHPass());             // Remove dead EH info
   if (Inliner) {
     MPM.add(Inliner);
-    Inliner = 0;
+    Inliner = nullptr;
   }
   if (!DisableUnitAtATime)
     MPM.add(createFunctionAttrsPass());       // Set readonly/readnone attrs
diff --git a/lib/Transforms/IPO/PruneEH.cpp b/lib/Transforms/IPO/PruneEH.cpp
index 5f89065ea7..b2c4a099b0 100644
--- a/lib/Transforms/IPO/PruneEH.cpp
+++ b/lib/Transforms/IPO/PruneEH.cpp
@@ -86,7 +86,7 @@ bool PruneEH::runOnSCC(CallGraphSCC &SCC) {
   for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); 
        (!SCCMightUnwind || !SCCMightReturn) && I != E; ++I) {
     Function *F = (*I)->getFunction();
-    if (F == 0) {
+    if (!F) {
       SCCMightUnwind = true;
       SCCMightReturn = true;
     } else if (F->isDeclaration() || F->mayBeOverridden()) {
diff --git a/lib/Transforms/IPO/StripSymbols.cpp b/lib/Transforms/IPO/StripSymbols.cpp
index 6d0be8fac2..1abbccc0fc 100644
--- a/lib/Transforms/IPO/StripSymbols.cpp
+++ b/lib/Transforms/IPO/StripSymbols.cpp
@@ -192,7 +192,7 @@ static void StripTypeNames(Module &M, bool PreserveDbgInfo) {
 /// Find values that are marked as llvm.used.
 static void findUsedValues(GlobalVariable *LLVMUsed,
                            SmallPtrSet<const GlobalValue*, 8> &UsedValues) {
-  if (LLVMUsed == 0) return;
+  if (!LLVMUsed) return;
   UsedValues.insert(LLVMUsed);
 
   ConstantArray *Inits = cast<ConstantArray>(LLVMUsed->getInitializer());