diff --git a/llvm/include/llvm/CodeGen/RDFGraph.h b/llvm/include/llvm/CodeGen/RDFGraph.h
index f76f6cdaa5bc..f3fe6ad81dd5 100644
--- a/llvm/include/llvm/CodeGen/RDFGraph.h
+++ b/llvm/include/llvm/CodeGen/RDFGraph.h
@@ -293,29 +293,29 @@ struct NodeAttrs {
   };
   // clang-format on
 
-  static uint16_t type(uint16_t T) { //
+  static auto type(uint16_t T) -> uint16_t { //
     return T & TypeMask;
   }
-  static uint16_t kind(uint16_t T) { //
+  static auto kind(uint16_t T) -> uint16_t { //
     return T & KindMask;
   }
-  static uint16_t flags(uint16_t T) { //
+  static auto flags(uint16_t T) -> uint16_t { //
     return T & FlagMask;
   }
-  static uint16_t set_type(uint16_t A, uint16_t T) {
+  static auto set_type(uint16_t A, uint16_t T) -> uint16_t {
     return (A & ~TypeMask) | T;
   }
 
-  static uint16_t set_kind(uint16_t A, uint16_t K) {
+  static auto set_kind(uint16_t A, uint16_t K) -> uint16_t {
     return (A & ~KindMask) | K;
   }
 
-  static uint16_t set_flags(uint16_t A, uint16_t F) {
+  static auto set_flags(uint16_t A, uint16_t F) -> uint16_t {
     return (A & ~FlagMask) | F;
   }
 
   // Test if A contains B.
-  static bool contains(uint16_t A, uint16_t B) {
+  static auto contains(uint16_t A, uint16_t B) -> bool {
     if (type(A) != Code)
       return false;
     uint16_t KB = kind(B);
@@ -348,11 +348,11 @@ template <typename T> struct NodeAddr {
   template <typename S>
   NodeAddr(const NodeAddr<S> &NA) : Addr(static_cast<T>(NA.Addr)), Id(NA.Id) {}
 
-  bool operator==(const NodeAddr<T> &NA) const {
+  auto operator==(const NodeAddr<T> &NA) const -> bool {
     assert((Addr == NA.Addr) == (Id == NA.Id));
     return Addr == NA.Addr;
   }
-  bool operator!=(const NodeAddr<T> &NA) const { //
+  auto operator!=(const NodeAddr<T> &NA) const -> bool {
     return !operator==(NA);
   }
 
@@ -414,22 +414,22 @@ struct NodeAllocator {
     assert(isPowerOf2_32(NPB));
   }
 
-  NodeBase *ptr(NodeId N) const {
+  auto ptr(NodeId N) const -> NodeBase * {
     uint32_t N1 = N - 1;
     uint32_t BlockN = N1 >> BitsPerIndex;
     uint32_t Offset = (N1 & IndexMask) * NodeMemSize;
     return reinterpret_cast<NodeBase *>(Blocks[BlockN] + Offset);
   }
 
-  NodeId id(const NodeBase *P) const;
-  Node New();
-  void clear();
+  auto id(const NodeBase *P) const -> NodeId;
+  auto New() -> Node;
+  auto clear() -> void;
 
 private:
-  void startNewBlock();
-  bool needNewBlock();
+  auto startNewBlock() -> void;
+  auto needNewBlock() -> bool;
 
-  uint32_t makeId(uint32_t Block, uint32_t Index) const {
+  auto makeId(uint32_t Block, uint32_t Index) const -> uint32_t {
     // Add 1 to the id, to avoid the id of 0, which is treated as "null".
     return ((Block << BitsPerIndex) | Index) + 1;
   }
@@ -449,9 +449,11 @@ struct TargetOperandInfo {
   TargetOperandInfo(const TargetInstrInfo &tii) : TII(tii) {}
   virtual ~TargetOperandInfo() = default;
 
-  virtual bool isPreserving(const MachineInstr &In, unsigned OpNum) const;
-  virtual bool isClobbering(const MachineInstr &In, unsigned OpNum) const;
-  virtual bool isFixedReg(const MachineInstr &In, unsigned OpNum) const;
+  virtual auto isPreserving(const MachineInstr &In, unsigned OpNum) const
+      -> bool;
+  virtual auto isClobbering(const MachineInstr &In, unsigned OpNum) const
+      -> bool;
+  virtual auto isFixedReg(const MachineInstr &In, unsigned OpNum) const -> bool;
 
   const TargetInstrInfo &TII;
 };
@@ -465,16 +467,16 @@ struct PackedRegisterRef {
 struct LaneMaskIndex : private IndexedSet<LaneBitmask> {
   LaneMaskIndex() = default;
 
-  LaneBitmask getLaneMaskForIndex(uint32_t K) const {
+  auto getLaneMaskForIndex(uint32_t K) const -> LaneBitmask {
     return K == 0 ? LaneBitmask::getAll() : get(K);
   }
 
-  uint32_t getIndexForLaneMask(LaneBitmask LM) {
+  auto getIndexForLaneMask(LaneBitmask LM) -> uint32_t {
     assert(LM.any());
     return LM.all() ? 0 : insert(LM);
   }
 
-  uint32_t getIndexForLaneMask(LaneBitmask LM) const {
+  auto getIndexForLaneMask(LaneBitmask LM) const -> uint32_t {
     assert(LM.any());
     return LM.all() ? 0 : find(LM);
   }
@@ -485,22 +487,24 @@ public:
   // Make sure this is a POD.
   NodeBase() = default;
 
-  uint16_t getType() const { return NodeAttrs::type(Attrs); }
-  uint16_t getKind() const { return NodeAttrs::kind(Attrs); }
-  uint16_t getFlags() const { return NodeAttrs::flags(Attrs); }
-  NodeId getNext() const { return Next; }
+  auto getType() const -> uint16_t { return NodeAttrs::type(Attrs); }
+  auto getKind() const -> uint16_t { return NodeAttrs::kind(Attrs); }
+  auto getFlags() const -> uint16_t { return NodeAttrs::flags(Attrs); }
+  auto getNext() const -> NodeId { return Next; }
 
-  uint16_t getAttrs() const { return Attrs; }
-  void setAttrs(uint16_t A) { Attrs = A; }
-  void setFlags(uint16_t F) { setAttrs(NodeAttrs::set_flags(getAttrs(), F)); }
+  auto getAttrs() const -> uint16_t { return Attrs; }
+  auto setAttrs(uint16_t A) -> void { Attrs = A; }
+  auto setFlags(uint16_t F) -> void {
+    setAttrs(NodeAttrs::set_flags(getAttrs(), F));
+  }
 
   // Insert node NA after "this" in the circular chain.
-  void append(Node NA);
+  auto append(Node NA) -> void;
 
   // Initialize all members to 0.
-  void init() { memset(this, 0, sizeof *this); }
+  auto init() -> void { memset(this, 0, sizeof *this); }
 
-  void setNext(NodeId N) { Next = N; }
+  auto setNext(NodeId N) -> void { Next = N; }
 
 protected:
   uint16_t Attrs;
@@ -549,108 +553,117 @@ using NodeSet = std::set<NodeId>;
 struct RefNode : public NodeBase {
   RefNode() = default;
 
-  RegisterRef getRegRef(const DataFlowGraph &G) const;
+  auto getRegRef(const DataFlowGraph &G) const -> RegisterRef;
 
-  MachineOperand &getOp() {
+  auto getOp() -> MachineOperand & {
     assert(!(getFlags() & NodeAttrs::PhiRef));
     return *RefData.Op;
   }
 
-  void setRegRef(RegisterRef RR, DataFlowGraph &G);
-  void setRegRef(MachineOperand *Op, DataFlowGraph &G);
+  auto setRegRef(RegisterRef RR, DataFlowGraph &G) -> void;
+  auto setRegRef(MachineOperand *Op, DataFlowGraph &G) -> void;
 
-  NodeId getReachingDef() const { return RefData.RD; }
-  void setReachingDef(NodeId RD) { RefData.RD = RD; }
+  auto getReachingDef() const -> NodeId { return RefData.RD; }
+  auto setReachingDef(NodeId RD) -> void { RefData.RD = RD; }
 
-  NodeId getSibling() const { return RefData.Sib; }
-  void setSibling(NodeId Sib) { RefData.Sib = Sib; }
+  auto getSibling() const -> NodeId { return RefData.Sib; }
+  auto setSibling(NodeId Sib) -> void { RefData.Sib = Sib; }
 
-  bool isUse() const {
+  auto isUse() const -> bool {
     assert(getType() == NodeAttrs::Ref);
     return getKind() == NodeAttrs::Use;
   }
 
-  bool isDef() const {
+  auto isDef() const -> bool {
     assert(getType() == NodeAttrs::Ref);
     return getKind() == NodeAttrs::Def;
   }
 
   template <typename Predicate>
-  Ref getNextRef(RegisterRef RR, Predicate P, bool NextOnly,
-                 const DataFlowGraph &G);
-  Node getOwner(const DataFlowGraph &G);
+  auto getNextRef(RegisterRef RR, Predicate P, bool NextOnly,
+                  const DataFlowGraph &G) -> Ref;
+  auto getOwner(const DataFlowGraph &G) -> Node;
 };
 
 struct DefNode : public RefNode {
-  NodeId getReachedDef() const { return RefData.Def.DD; }
-  void setReachedDef(NodeId D) { RefData.Def.DD = D; }
-  NodeId getReachedUse() const { return RefData.Def.DU; }
-  void setReachedUse(NodeId U) { RefData.Def.DU = U; }
+  auto getReachedDef() const -> NodeId { //
+    return RefData.Def.DD;
+  }
+  auto setReachedDef(NodeId D) -> void { //
+    RefData.Def.DD = D;
+  }
+  auto getReachedUse() const -> NodeId { //
+    return RefData.Def.DU;
+  }
+  auto setReachedUse(NodeId U) -> void { //
+    RefData.Def.DU = U;
+  }
 
-  void linkToDef(NodeId Self, Def DA);
+  auto linkToDef(NodeId Self, Def DA) -> void;
 };
 
 struct UseNode : public RefNode {
-  void linkToDef(NodeId Self, Def DA);
+  auto linkToDef(NodeId Self, Def DA) -> void;
 };
 
 struct PhiUseNode : public UseNode {
-  NodeId getPredecessor() const {
+  auto getPredecessor() const -> NodeId {
     assert(getFlags() & NodeAttrs::PhiRef);
     return RefData.PhiU.PredB;
   }
-  void setPredecessor(NodeId B) {
+  auto setPredecessor(NodeId B) -> void {
     assert(getFlags() & NodeAttrs::PhiRef);
     RefData.PhiU.PredB = B;
   }
 };
 
 struct CodeNode : public NodeBase {
-  template <typename T> T getCode() const { //
+  template <typename T> auto getCode() const -> T {
     return static_cast<T>(CodeData.CP);
   }
-  void setCode(void *C) { CodeData.CP = C; }
+  auto setCode(void *C) -> void { CodeData.CP = C; }
 
-  Node getFirstMember(const DataFlowGraph &G) const;
-  Node getLastMember(const DataFlowGraph &G) const;
-  void addMember(Node NA, const DataFlowGraph &G);
-  void addMemberAfter(Node MA, Node NA, const DataFlowGraph &G);
-  void removeMember(Node NA, const DataFlowGraph &G);
+  auto getFirstMember(const DataFlowGraph &G) const -> Node;
+  auto getLastMember(const DataFlowGraph &G) const -> Node;
+  auto addMember(Node NA, const DataFlowGraph &G) -> void;
+  auto addMemberAfter(Node MA, Node NA, const DataFlowGraph &G) -> void;
+  auto removeMember(Node NA, const DataFlowGraph &G) -> void;
 
-  NodeList members(const DataFlowGraph &G) const;
+  auto members(const DataFlowGraph &G) const -> NodeList;
   template <typename Predicate>
-  NodeList members_if(Predicate P, const DataFlowGraph &G) const;
+  auto members_if(Predicate P, const DataFlowGraph &G) const -> NodeList;
 };
 
 struct InstrNode : public CodeNode {
-  Node getOwner(const DataFlowGraph &G);
+  auto getOwner(const DataFlowGraph &G) -> Node;
 };
 
 struct PhiNode : public InstrNode {
-  MachineInstr *getCode() const { return nullptr; }
+  auto getCode() const -> MachineInstr * { return nullptr; }
 };
 
 struct StmtNode : public InstrNode {
-  MachineInstr *getCode() const { //
+  auto getCode() const -> MachineInstr * {
     return CodeNode::getCode<MachineInstr *>();
   }
 };
 
 struct BlockNode : public CodeNode {
-  MachineBasicBlock *getCode() const {
+  auto getCode() const -> MachineBasicBlock * {
     return CodeNode::getCode<MachineBasicBlock *>();
   }
 
-  void addPhi(Phi PA, const DataFlowGraph &G);
+  auto addPhi(Phi PA, const DataFlowGraph &G) -> void;
 };
 
 struct FuncNode : public CodeNode {
-  MachineFunction *getCode() const {
+  auto getCode() const -> MachineFunction * {
     return CodeNode::getCode<MachineFunction *>();
   }
 
-  Block findBlock(const MachineBasicBlock *BB, const DataFlowGraph &G) const;
-  Block getEntryBlock(const DataFlowGraph &G);
+  auto findBlock(const MachineBasicBlock *BB, const DataFlowGraph &G) const
+      -> Block;
+  auto getEntryBlock(const DataFlowGraph &G) -> Block;
 };
 
 struct DataFlowGraph {
@@ -662,55 +675,59 @@ struct DataFlowGraph {
                 const MachineDominanceFrontier &mdf,
                 const TargetOperandInfo &toi);
 
-  NodeBase *ptr(NodeId N) const;
-  template <typename T> T ptr(NodeId N) const { //
+  auto ptr(NodeId N) const -> NodeBase *;
+  template <typename T> auto ptr(NodeId N) const -> T {
     return static_cast<T>(ptr(N));
   }
 
-  NodeId id(const NodeBase *P) const;
+  auto id(const NodeBase *P) const -> NodeId;
 
-  template <typename T> NodeAddr<T> addr(NodeId N) const {
+  template <typename T> auto addr(NodeId N) const -> NodeAddr<T> {
     return {ptr<T>(N), N};
   }
 
-  Func getFunc() const { return TheFunc; }
-  MachineFunction &getMF() const { return MF; }
-  const TargetInstrInfo &getTII() const { return TII; }
-  const TargetRegisterInfo &getTRI() const { return TRI; }
-  const PhysicalRegisterInfo &getPRI() const { return PRI; }
-  const MachineDominatorTree &getDT() const { return MDT; }
-  const MachineDominanceFrontier &getDF() const { return MDF; }
-  const RegisterAggr &getLiveIns() const { return LiveIns; }
+  auto getFunc() const -> Func { return TheFunc; }
+  auto getMF() const -> MachineFunction & { return MF; }
+  auto getTII() const -> const TargetInstrInfo & { return TII; }
+  auto getTRI() const -> const TargetRegisterInfo & { return TRI; }
+  auto getPRI() const -> const PhysicalRegisterInfo & { return PRI; }
+  auto getDT() const -> const MachineDominatorTree & { return MDT; }
+  auto getDF() const -> const MachineDominanceFrontier & { return MDF; }
+  auto getLiveIns() const -> const RegisterAggr & { return LiveIns; }
 
   struct DefStack {
     DefStack() = default;
 
-    bool empty() const { return Stack.empty() || top() == bottom(); }
+    auto empty() const -> bool { return Stack.empty() || top() == bottom(); }
 
   private:
     using value_type = Def;
     struct Iterator {
       using value_type = DefStack::value_type;
 
-      Iterator &up() {
+      auto up() -> Iterator & {
         Pos = DS.nextUp(Pos);
         return *this;
       }
-      Iterator &down() {
+      auto down() -> Iterator & {
         Pos = DS.nextDown(Pos);
         return *this;
       }
 
-      value_type operator*() const {
+      auto operator*() const -> value_type {
         assert(Pos >= 1);
         return DS.Stack[Pos - 1];
       }
-      const value_type *operator->() const {
+      auto operator->() const -> const value_type * {
         assert(Pos >= 1);
         return &DS.Stack[Pos - 1];
       }
-      bool operator==(const Iterator &It) const { return Pos == It.Pos; }
-      bool operator!=(const Iterator &It) const { return Pos != It.Pos; }
+      auto operator==(const Iterator &It) const -> bool {
+        return Pos == It.Pos;
+      }
+      auto operator!=(const Iterator &It) const -> bool {
+        return Pos != It.Pos;
+      }
 
     private:
       friend struct DefStack;
@@ -726,26 +743,27 @@ struct DataFlowGraph {
   public:
     using iterator = Iterator;
 
-    iterator top() const { return Iterator(*this, true); }
-    iterator bottom() const { return Iterator(*this, false); }
-    unsigned size() const;
+    auto top() const -> iterator { return Iterator(*this, true); }
+    auto bottom() const -> iterator { return Iterator(*this, false); }
+    auto size() const -> unsigned;
 
-    void push(Def DA) { Stack.push_back(DA); }
-    void pop();
-    void start_block(NodeId N);
-    void clear_block(NodeId N);
+    auto push(Def DA) -> void { Stack.push_back(DA); }
+    auto pop() -> void;
+    auto start_block(NodeId N) -> void;
+    auto clear_block(NodeId N) -> void;
 
   private:
     friend struct Iterator;
 
     using StorageType = std::vector<value_type>;
 
-    bool isDelimiter(const StorageType::value_type &P, NodeId N = 0) const {
+    auto isDelimiter(const StorageType::value_type &P, NodeId N = 0) const
+        -> bool {
       return (P.Addr == nullptr) && (N == 0 || P.Id == N);
     }
 
-    unsigned nextUp(unsigned P) const;
-    unsigned nextDown(unsigned P) const;
+    auto nextUp(unsigned P) const -> unsigned;
+    auto nextDown(unsigned P) const -> unsigned;
 
     StorageType Stack;
   };
@@ -754,111 +772,118 @@ struct DataFlowGraph {
   // Map: Register (physical or virtual) -> DefStack
   using DefStackMap = std::unordered_map<RegisterId, DefStack>;
 
-  void build(unsigned Options = BuildOptions::None);
-  void pushAllDefs(Instr IA, DefStackMap &DM);
-  void markBlock(NodeId B, DefStackMap &DefM);
-  void releaseBlock(NodeId B, DefStackMap &DefM);
+  auto build(unsigned Options = BuildOptions::None) -> void;
+  auto pushAllDefs(Instr IA, DefStackMap &DM) -> void;
+  auto markBlock(NodeId B, DefStackMap &DefM) -> void;
+  auto releaseBlock(NodeId B, DefStackMap &DefM) -> void;
 
-  PackedRegisterRef pack(RegisterRef RR) {
+  auto pack(RegisterRef RR) -> PackedRegisterRef {
     return {RR.Reg, LMI.getIndexForLaneMask(RR.Mask)};
   }
-  PackedRegisterRef pack(RegisterRef RR) const {
+  auto pack(RegisterRef RR) const -> PackedRegisterRef {
     return {RR.Reg, LMI.getIndexForLaneMask(RR.Mask)};
   }
-  RegisterRef unpack(PackedRegisterRef PR) const {
+  auto unpack(PackedRegisterRef PR) const -> RegisterRef {
     return RegisterRef(PR.Reg, LMI.getLaneMaskForIndex(PR.MaskId));
   }
 
-  RegisterRef makeRegRef(unsigned Reg, unsigned Sub) const;
-  RegisterRef makeRegRef(const MachineOperand &Op) const;
+  auto makeRegRef(unsigned Reg, unsigned Sub) const -> RegisterRef;
+  auto makeRegRef(const MachineOperand &Op) const -> RegisterRef;
 
-  Ref getNextRelated(Instr IA, Ref RA) const;
-  Ref getNextShadow(Instr IA, Ref RA, bool Create);
-  Ref getNextShadow(Instr IA, Ref RA) const;
+  auto getNextRelated(Instr IA, Ref RA) const -> Ref;
+  auto getNextShadow(Instr IA, Ref RA, bool Create) -> Ref;
+  auto getNextShadow(Instr IA, Ref RA) const -> Ref;
 
-  NodeList getRelatedRefs(Instr IA, Ref RA) const;
+  auto getRelatedRefs(Instr IA, Ref RA) const -> NodeList;
 
-  Block findBlock(MachineBasicBlock *BB) const { return BlockNodes.at(BB); }
+  auto findBlock(MachineBasicBlock *BB) const -> Block {
+    return BlockNodes.at(BB);
+  }
 
-  void unlinkUse(Use UA, bool RemoveFromOwner) {
+  auto unlinkUse(Use UA, bool RemoveFromOwner) -> void {
     unlinkUseDF(UA);
     if (RemoveFromOwner)
       removeFromOwner(UA);
   }
 
-  void unlinkDef(Def DA, bool RemoveFromOwner) {
+  auto unlinkDef(Def DA, bool RemoveFromOwner) -> void {
     unlinkDefDF(DA);
     if (RemoveFromOwner)
       removeFromOwner(DA);
   }
 
   // Some useful filters.
-  template <uint16_t Kind> static bool IsRef(const Node BA) {
+  template <uint16_t Kind> static auto IsRef(const Node BA) -> bool {
     return BA.Addr->getType() == NodeAttrs::Ref && BA.Addr->getKind() == Kind;
   }
 
-  template <uint16_t Kind> static bool IsCode(const Node BA) {
+  template <uint16_t Kind> static auto IsCode(const Node BA) -> bool {
     return BA.Addr->getType() == NodeAttrs::Code && BA.Addr->getKind() == Kind;
   }
 
-  static bool IsDef(const Node BA) {
+  static auto IsDef(const Node BA) -> bool {
     return BA.Addr->getType() == NodeAttrs::Ref &&
            BA.Addr->getKind() == NodeAttrs::Def;
   }
 
-  static bool IsUse(const Node BA) {
+  static auto IsUse(const Node BA) -> bool {
     return BA.Addr->getType() == NodeAttrs::Ref &&
            BA.Addr->getKind() == NodeAttrs::Use;
   }
 
-  static bool IsPhi(const Node BA) {
+  static auto IsPhi(const Node BA) -> bool {
     return BA.Addr->getType() == NodeAttrs::Code &&
            BA.Addr->getKind() == NodeAttrs::Phi;
   }
 
-  static bool IsPreservingDef(const Def DA) {
+  static auto IsPreservingDef(const Def DA) -> bool {
     uint16_t Flags = DA.Addr->getFlags();
     return (Flags & NodeAttrs::Preserving) && !(Flags & NodeAttrs::Undef);
   }
 
 private:
-  void reset();
+  auto reset() -> void;
 
-  RegisterAggr getLandingPadLiveIns() const;
+  auto getLandingPadLiveIns() const -> RegisterAggr;
 
-  Node newNode(uint16_t Attrs);
-  Node cloneNode(const Node B);
-  Use newUse(Instr Owner, MachineOperand &Op, uint16_t Flags = NodeAttrs::None);
-  PhiUse newPhiUse(Phi Owner, RegisterRef RR, Block PredB,
-                   uint16_t Flags = NodeAttrs::PhiRef);
-  Def newDef(Instr Owner, MachineOperand &Op, uint16_t Flags = NodeAttrs::None);
-  Def newDef(Instr Owner, RegisterRef RR, uint16_t Flags = NodeAttrs::PhiRef);
-  Phi newPhi(Block Owner);
-  Stmt newStmt(Block Owner, MachineInstr *MI);
-  Block newBlock(Func Owner, MachineBasicBlock *BB);
-  Func newFunc(MachineFunction *MF);
+  auto newNode(uint16_t Attrs) -> Node;
+  auto cloneNode(const Node B) -> Node;
+  auto newUse(Instr Owner, MachineOperand &Op, uint16_t Flags = NodeAttrs::None)
+      -> Use;
+  auto newPhiUse(Phi Owner, RegisterRef RR, Block PredB,
+                 uint16_t Flags = NodeAttrs::PhiRef) -> PhiUse;
+  auto newDef(Instr Owner, MachineOperand &Op, uint16_t Flags = NodeAttrs::None)
+      -> Def;
+  auto newDef(Instr Owner, RegisterRef RR, uint16_t Flags = NodeAttrs::PhiRef)
+      -> Def;
+  auto newPhi(Block Owner) -> Phi;
+  auto newStmt(Block Owner, MachineInstr *MI) -> Stmt;
+  auto newBlock(Func Owner, MachineBasicBlock *BB) -> Block;
+  auto newFunc(MachineFunction *MF) -> Func;
 
   template <typename Predicate>
-  std::pair<Ref, Ref> locateNextRef(Instr IA, Ref RA, Predicate P) const;
+  auto locateNextRef(Instr IA, Ref RA, Predicate P) const
+      -> std::pair<Ref, Ref>;
 
   using BlockRefsMap = RegisterAggrMap<NodeId>;
 
-  void buildStmt(Block BA, MachineInstr &In);
-  void recordDefsForDF(BlockRefsMap &PhiM, Block BA);
-  void buildPhis(BlockRefsMap &PhiM, RegisterSet &AllRefs, Block BA);
-  void removeUnusedPhis();
+  auto buildStmt(Block BA, MachineInstr &In) -> void;
+  auto recordDefsForDF(BlockRefsMap &PhiM, Block BA) -> void;
+  auto buildPhis(BlockRefsMap &PhiM, RegisterSet &AllRefs, Block BA) -> void;
+  auto removeUnusedPhis() -> void;
 
-  void pushClobbers(Instr IA, DefStackMap &DM);
-  void pushDefs(Instr IA, DefStackMap &DM);
-  template <typename T> void linkRefUp(Instr IA, NodeAddr<T> TA, DefStack &DS);
+  auto pushClobbers(Instr IA, DefStackMap &DM) -> void;
+  auto pushDefs(Instr IA, DefStackMap &DM) -> void;
+  template <typename T>
+  auto linkRefUp(Instr IA, NodeAddr<T> TA, DefStack &DS) -> void;
   template <typename Predicate>
-  void linkStmtRefs(DefStackMap &DefM, Stmt SA, Predicate P);
-  void linkBlockRefs(DefStackMap &DefM, Block BA);
+  auto linkStmtRefs(DefStackMap &DefM, Stmt SA, Predicate P) -> void;
+  auto linkBlockRefs(DefStackMap &DefM, Block BA) -> void;
 
-  void unlinkUseDF(Use UA);
-  void unlinkDefDF(Def DA);
+  auto unlinkUseDF(Use UA) -> void;
+  auto unlinkDefDF(Def DA) -> void;
 
-  void removeFromOwner(Ref RA) {
+  auto removeFromOwner(Ref RA) -> void {
     Instr IA = RA.Addr->getOwner(*this);
     IA.Addr->removeMember(RA, *this);
   }
@@ -884,8 +909,8 @@ private:
 }; // struct DataFlowGraph
 
 template <typename Predicate>
-Ref RefNode::getNextRef(RegisterRef RR, Predicate P, bool NextOnly,
-                        const DataFlowGraph &G) {
+auto RefNode::getNextRef(RegisterRef RR, Predicate P, bool NextOnly,
+                         const DataFlowGraph &G) -> Ref {
   // Get the "Next" reference in the circular list that references RR and
   // satisfies predicate "Pred".
   auto NA = G.addr<NodeBase *>(getNext());
@@ -910,7 +935,8 @@ Ref RefNode::getNextRef(RegisterRef RR, Predicate P, bool NextOnly,
 }
 
 template <typename Predicate>
-NodeList CodeNode::members_if(Predicate P, const DataFlowGraph &G) const {
+auto CodeNode::members_if(Predicate P, const DataFlowGraph &G) const
+    -> NodeList {
   NodeList MM;
   auto M = getFirstMember(G);
   if (M.Id == 0)
@@ -938,23 +964,23 @@ template <typename T> struct PrintNode : Print<NodeAddr<T>> {
       : Print<NodeAddr<T>>(x, g) {}
 };
 
-raw_ostream &operator<<(raw_ostream &OS, const Print<RegisterRef> &P);
-raw_ostream &operator<<(raw_ostream &OS, const Print<NodeId> &P);
-raw_ostream &operator<<(raw_ostream &OS, const Print<Def> &P);
-raw_ostream &operator<<(raw_ostream &OS, const Print<Use> &P);
-raw_ostream &operator<<(raw_ostream &OS, const Print<PhiUse> &P);
-raw_ostream &operator<<(raw_ostream &OS, const Print<Ref> &P);
-raw_ostream &operator<<(raw_ostream &OS, const Print<NodeList> &P);
-raw_ostream &operator<<(raw_ostream &OS, const Print<NodeSet> &P);
-raw_ostream &operator<<(raw_ostream &OS, const Print<Phi> &P);
-raw_ostream &operator<<(raw_ostream &OS, const Print<Stmt> &P);
-raw_ostream &operator<<(raw_ostream &OS, const Print<Instr> &P);
-raw_ostream &operator<<(raw_ostream &OS, const Print<Block> &P);
-raw_ostream &operator<<(raw_ostream &OS, const Print<Func> &P);
-raw_ostream &operator<<(raw_ostream &OS, const Print<RegisterSet> &P);
-raw_ostream &operator<<(raw_ostream &OS, const Print<RegisterAggr> &P);
-raw_ostream &operator<<(raw_ostream &OS,
-                        const Print<DataFlowGraph::DefStack> &P);
+auto operator<<(raw_ostream &OS, const Print<RegisterRef> &P) -> raw_ostream &;
+auto operator<<(raw_ostream &OS, const Print<NodeId> &P) -> raw_ostream &;
+auto operator<<(raw_ostream &OS, const Print<Def> &P) -> raw_ostream &;
+auto operator<<(raw_ostream &OS, const Print<Use> &P) -> raw_ostream &;
+auto operator<<(raw_ostream &OS, const Print<PhiUse> &P) -> raw_ostream &;
+auto operator<<(raw_ostream &OS, const Print<Ref> &P) -> raw_ostream &;
+auto operator<<(raw_ostream &OS, const Print<NodeList> &P) -> raw_ostream &;
+auto operator<<(raw_ostream &OS, const Print<NodeSet> &P) -> raw_ostream &;
+auto operator<<(raw_ostream &OS, const Print<Phi> &P) -> raw_ostream &;
+auto operator<<(raw_ostream &OS, const Print<Stmt> &P) -> raw_ostream &;
+auto operator<<(raw_ostream &OS, const Print<Instr> &P) -> raw_ostream &;
+auto operator<<(raw_ostream &OS, const Print<Block> &P) -> raw_ostream &;
+auto operator<<(raw_ostream &OS, const Print<Func> &P) -> raw_ostream &;
+auto operator<<(raw_ostream &OS, const Print<RegisterSet> &P) -> raw_ostream &;
+auto operator<<(raw_ostream &OS, const Print<RegisterAggr> &P) -> raw_ostream &;
+auto operator<<(raw_ostream &OS, const Print<DataFlowGraph::DefStack> &P)
+    -> raw_ostream &;
 
 } // end namespace rdf
 
diff --git a/llvm/lib/CodeGen/RDFGraph.cpp b/llvm/lib/CodeGen/RDFGraph.cpp
index 1b1c34f475c1..b4254e45f871 100644
--- a/llvm/lib/CodeGen/RDFGraph.cpp
+++ b/llvm/lib/CodeGen/RDFGraph.cpp
@@ -46,12 +46,12 @@ using namespace rdf;
 namespace llvm {
 namespace rdf {
 
-raw_ostream &operator<<(raw_ostream &OS, const Print<RegisterRef> &P) {
+auto operator<<(raw_ostream &OS, const Print<RegisterRef> &P) -> raw_ostream & {
   P.G.getPRI().print(OS, P.Obj);
   return OS;
 }
 
-raw_ostream &operator<<(raw_ostream &OS, const Print<NodeId> &P) {
+auto operator<<(raw_ostream &OS, const Print<NodeId> &P) -> raw_ostream & {
   auto NA = P.G.addr<NodeBase *>(P.Obj);
   uint16_t Attrs = NA.Addr->getAttrs();
   uint16_t Kind = NodeAttrs::kind(Attrs);
@@ -110,14 +110,14 @@ raw_ostream &operator<<(raw_ostream &OS, const Print<NodeId> &P) {
   return OS;
 }
 
-static void printRefHeader(raw_ostream &OS, const Ref RA,
-                           const DataFlowGraph &G) {
+static auto printRefHeader(raw_ostream &OS, const Ref RA,
+                           const DataFlowGraph &G) -> void {
   OS << Print(RA.Id, G) << '<' << Print(RA.Addr->getRegRef(G), G) << '>';
   if (RA.Addr->getFlags() & NodeAttrs::Fixed)
     OS << '!';
 }
 
-raw_ostream &operator<<(raw_ostream &OS, const Print<Def> &P) {
+auto operator<<(raw_ostream &OS, const Print<Def> &P) -> raw_ostream & {
   printRefHeader(OS, P.Obj, P.G);
   OS << '(';
   if (NodeId N = P.Obj.Addr->getReachingDef())
@@ -134,7 +134,7 @@ raw_ostream &operator<<(raw_ostream &OS, const Print<Def> &P) {
   return OS;
 }
 
-raw_ostream &operator<<(raw_ostream &OS, const Print<Use> &P) {
+auto operator<<(raw_ostream &OS, const Print<Use> &P) -> raw_ostream & {
   printRefHeader(OS, P.Obj, P.G);
   OS << '(';
   if (NodeId N = P.Obj.Addr->getReachingDef())
@@ -145,7 +145,7 @@ raw_ostream &operator<<(raw_ostream &OS, const Print<Use> &P) {
   return OS;
 }
 
-raw_ostream &operator<<(raw_ostream &OS, const Print<PhiUse> &P) {
+auto operator<<(raw_ostream &OS, const Print<PhiUse> &P) -> raw_ostream & {
   printRefHeader(OS, P.Obj, P.G);
   OS << '(';
   if (NodeId N = P.Obj.Addr->getReachingDef())
@@ -159,7 +159,7 @@ raw_ostream &operator<<(raw_ostream &OS, const Print<PhiUse> &P) {
   return OS;
 }
 
-raw_ostream &operator<<(raw_ostream &OS, const Print<Ref> &P) {
+auto operator<<(raw_ostream &OS, const Print<Ref> &P) -> raw_ostream & {
   switch (P.Obj.Addr->getKind()) {
   case NodeAttrs::Def:
     OS << PrintNode<DefNode *>(P.Obj, P.G);
@@ -174,7 +174,7 @@ raw_ostream &operator<<(raw_ostream &OS, const Print<Ref> &P) {
   return OS;
 }
 
-raw_ostream &operator<<(raw_ostream &OS, const Print<NodeList> &P) {
+auto operator<<(raw_ostream &OS, const Print<NodeList> &P) -> raw_ostream & {
   unsigned N = P.Obj.size();
   for (auto I : P.Obj) {
     OS << Print(I.Id, P.G);
@@ -184,7 +184,7 @@ raw_ostream &operator<<(raw_ostream &OS, const Print<NodeList> &P) {
   return OS;
 }
 
-raw_ostream &operator<<(raw_ostream &OS, const Print<NodeSet> &P) {
+auto operator<<(raw_ostream &OS, const Print<NodeSet> &P) -> raw_ostream & {
   unsigned N = P.Obj.size();
   for (auto I : P.Obj) {
     OS << Print(I, P.G);
@@ -205,7 +205,7 @@ template <typename T> struct PrintListV {
 };
 
 template <typename T>
-raw_ostream &operator<<(raw_ostream &OS, const PrintListV<T> &P) {
+auto operator<<(raw_ostream &OS, const PrintListV<T> &P) -> raw_ostream & {
   unsigned N = P.List.size();
   for (NodeAddr<T> A : P.List) {
     OS << PrintNode<T>(A, P.G);
@@ -217,13 +217,13 @@ raw_ostream &operator<<(raw_ostream &OS, const PrintListV<T> &P) {
 
 } // end anonymous namespace
 
-raw_ostream &operator<<(raw_ostream &OS, const Print<Phi> &P) {
+auto operator<<(raw_ostream &OS, const Print<Phi> &P) -> raw_ostream & {
   OS << Print(P.Obj.Id, P.G) << ": phi ["
      << PrintListV<RefNode *>(P.Obj.Addr->members(P.G), P.G) << ']';
   return OS;
 }
 
-raw_ostream &operator<<(raw_ostream &OS, const Print<Stmt> &P) {
+auto operator<<(raw_ostream &OS, const Print<Stmt> &P) -> raw_ostream & {
   const MachineInstr &MI = *P.Obj.Addr->getCode();
   unsigned Opc = MI.getOpcode();
   OS << Print(P.Obj.Id, P.G) << ": " << P.G.getTII().getName(Opc);
@@ -247,7 +247,7 @@ raw_ostream &operator<<(raw_ostream &OS, const Print<Stmt> &P) {
   return OS;
 }
 
-raw_ostream &operator<<(raw_ostream &OS, const Print<Instr> &P) {
+auto operator<<(raw_ostream &OS, const Print<Instr> &P) -> raw_ostream & {
   switch (P.Obj.Addr->getKind()) {
   case NodeAttrs::Phi:
     OS << PrintNode<PhiNode *>(P.Obj, P.G);
@@ -262,7 +262,7 @@ raw_ostream &operator<<(raw_ostream &OS, const Print<Instr> &P) {
   return OS;
 }
 
-raw_ostream &operator<<(raw_ostream &OS, const Print<Block> &P) {
+auto operator<<(raw_ostream &OS, const Print<Block> &P) -> raw_ostream & {
   MachineBasicBlock *BB = P.Obj.Addr->getCode();
   unsigned NP = BB->pred_size();
   std::vector<int> Ns;
@@ -294,7 +294,7 @@ raw_ostream &operator<<(raw_ostream &OS, const Print<Block> &P) {
   return OS;
 }
 
-raw_ostream &operator<<(raw_ostream &OS, const Print<Func> &P) {
+auto operator<<(raw_ostream &OS, const Print<Func> &P) -> raw_ostream & {
   OS << "DFG dump:[\n"
      << Print(P.Obj.Id, P.G)
      << ": Function: " << P.Obj.Addr->getCode()->getName() << '\n';
@@ -304,7 +304,7 @@ raw_ostream &operator<<(raw_ostream &OS, const Print<Func> &P) {
   return OS;
 }
 
-raw_ostream &operator<<(raw_ostream &OS, const Print<RegisterSet> &P) {
+auto operator<<(raw_ostream &OS, const Print<RegisterSet> &P) -> raw_ostream & {
   OS << '{';
   for (auto I : P.Obj)
     OS << ' ' << Print(I, P.G);
@@ -312,13 +312,14 @@ raw_ostream &operator<<(raw_ostream &OS, const Print<RegisterSet> &P) {
   return OS;
 }
 
-raw_ostream &operator<<(raw_ostream &OS, const Print<RegisterAggr> &P) {
+auto operator<<(raw_ostream &OS, const Print<RegisterAggr> &P)
+    -> raw_ostream & {
   OS << P.Obj;
   return OS;
 }
 
-raw_ostream &operator<<(raw_ostream &OS,
-                        const Print<DataFlowGraph::DefStack> &P) {
+auto operator<<(raw_ostream &OS, const Print<DataFlowGraph::DefStack> &P)
+    -> raw_ostream & {
   for (auto I = P.Obj.top(), E = P.Obj.bottom(); I != E;) {
     OS << Print(I->Id, P.G) << '<' << Print(I->Addr->getRegRef(P.G), P.G)
        << '>';
@@ -341,7 +342,7 @@ raw_ostream &operator<<(raw_ostream &OS,
 // There is a mapping scheme between node id and its location in a block,
 // and within that block is described in the header file.
 //
-void NodeAllocator::startNewBlock() {
+auto NodeAllocator::startNewBlock() -> void {
   void *T = MemPool.Allocate(NodesPerBlock * NodeMemSize, NodeMemSize);
   char *P = static_cast<char *>(T);
   Blocks.push_back(P);
@@ -353,7 +354,7 @@ void NodeAllocator::startNewBlock() {
   ActiveEnd = P;
 }
 
-bool NodeAllocator::needNewBlock() {
+auto NodeAllocator::needNewBlock() -> bool {
   if (Blocks.empty())
     return true;
 
@@ -362,7 +363,7 @@ bool NodeAllocator::needNewBlock() {
   return Index >= NodesPerBlock;
 }
 
-Node NodeAllocator::New() {
+auto NodeAllocator::New() -> Node {
   if (needNewBlock())
     startNewBlock();
 
@@ -373,7 +374,7 @@ Node NodeAllocator::New() {
   return NA;
 }
 
-NodeId NodeAllocator::id(const NodeBase *P) const {
+auto NodeAllocator::id(const NodeBase *P) const -> NodeId {
   uintptr_t A = reinterpret_cast<uintptr_t>(P);
   for (unsigned i = 0, n = Blocks.size(); i != n; ++i) {
     uintptr_t B = reinterpret_cast<uintptr_t>(Blocks[i]);
@@ -385,14 +386,14 @@ NodeId NodeAllocator::id(const NodeBase *P) const {
   llvm_unreachable("Invalid node address");
 }
 
-void NodeAllocator::clear() {
+auto NodeAllocator::clear() -> void {
   MemPool.Reset();
   Blocks.clear();
   ActiveEnd = nullptr;
 }
 
 // Insert node NA after "this" in the circular chain.
-void NodeBase::append(Node NA) {
+auto NodeBase::append(Node NA) -> void {
   NodeId Nx = Next;
   // If NA is already "next", do nothing.
   if (Next != NA.Id) {
@@ -404,7 +405,7 @@ void NodeBase::append(Node NA) {
 // Fundamental node manipulator functions.
 
 // Obtain the register reference from a reference node.
-RegisterRef RefNode::getRegRef(const DataFlowGraph &G) const {
+auto RefNode::getRegRef(const DataFlowGraph &G) const -> RegisterRef {
   assert(NodeAttrs::type(Attrs) == NodeAttrs::Ref);
   if (NodeAttrs::flags(Attrs) & NodeAttrs::PhiRef)
     return G.unpack(RefData.PR);
@@ -414,7 +415,7 @@ RegisterRef RefNode::getRegRef(const DataFlowGraph &G) const {
 
 // Set the register reference in the reference node directly (for references
 // in phi nodes).
-void RefNode::setRegRef(RegisterRef RR, DataFlowGraph &G) {
+auto RefNode::setRegRef(RegisterRef RR, DataFlowGraph &G) -> void {
   assert(NodeAttrs::type(Attrs) == NodeAttrs::Ref);
   assert(NodeAttrs::flags(Attrs) & NodeAttrs::PhiRef);
   RefData.PR = G.pack(RR);
@@ -422,7 +423,7 @@ void RefNode::setRegRef(RegisterRef RR, DataFlowGraph &G) {
 
 // Set the register reference in the reference node based on a machine
 // operand (for references in statement nodes).
-void RefNode::setRegRef(MachineOperand *Op, DataFlowGraph &G) {
+auto RefNode::setRegRef(MachineOperand *Op, DataFlowGraph &G) -> void {
   assert(NodeAttrs::type(Attrs) == NodeAttrs::Ref);
   assert(!(NodeAttrs::flags(Attrs) & NodeAttrs::PhiRef));
   (void)G;
@@ -430,7 +431,7 @@ void RefNode::setRegRef(MachineOperand *Op, DataFlowGraph &G) {
 }
 
 // Get the owner of a given reference node.
-Node RefNode::getOwner(const DataFlowGraph &G) {
+auto RefNode::getOwner(const DataFlowGraph &G) -> Node {
   Node NA = G.addr<NodeBase *>(getNext());
 
   while (NA.Addr != this) {
@@ -442,35 +443,35 @@ Node RefNode::getOwner(const DataFlowGraph &G) {
 }
 
 // Connect the def node to the reaching def node.
-void DefNode::linkToDef(NodeId Self, Def DA) {
+auto DefNode::linkToDef(NodeId Self, Def DA) -> void {
   RefData.RD = DA.Id;
   RefData.Sib = DA.Addr->getReachedDef();
   DA.Addr->setReachedDef(Self);
 }
 
 // Connect the use node to the reaching def node.
-void UseNode::linkToDef(NodeId Self, Def DA) {
+auto UseNode::linkToDef(NodeId Self, Def DA) -> void {
   RefData.RD = DA.Id;
   RefData.Sib = DA.Addr->getReachedUse();
   DA.Addr->setReachedUse(Self);
 }
 
 // Get the first member of the code node.
-Node CodeNode::getFirstMember(const DataFlowGraph &G) const {
+auto CodeNode::getFirstMember(const DataFlowGraph &G) const -> Node {
   if (CodeData.FirstM == 0)
     return Node();
   return G.addr<NodeBase *>(CodeData.FirstM);
 }
 
 // Get the last member of the code node.
-Node CodeNode::getLastMember(const DataFlowGraph &G) const {
+auto CodeNode::getLastMember(const DataFlowGraph &G) const -> Node {
   if (CodeData.LastM == 0)
     return Node();
   return G.addr<NodeBase *>(CodeData.LastM);
 }
 
 // Add node NA at the end of the member list of the given code node.
-void CodeNode::addMember(Node NA, const DataFlowGraph &G) {
+auto CodeNode::addMember(Node NA, const DataFlowGraph &G) -> void {
   Node ML = getLastMember(G);
   if (ML.Id != 0) {
     ML.Addr->append(NA);
@@ -483,14 +484,15 @@ void CodeNode::addMember(Node NA, const DataFlowGraph &G) {
 }
 
 // Add node NA after member node MA in the given code node.
-void CodeNode::addMemberAfter(Node MA, Node NA, const DataFlowGraph &G) {
+auto CodeNode::addMemberAfter(Node MA, Node NA, const DataFlowGraph &G)
+    -> void {
   MA.Addr->append(NA);
   if (CodeData.LastM == MA.Id)
     CodeData.LastM = NA.Id;
 }
 
 // Remove member node NA from the given code node.
-void CodeNode::removeMember(Node NA, const DataFlowGraph &G) {
+auto CodeNode::removeMember(Node NA, const DataFlowGraph &G) -> void {
   Node MA = getFirstMember(G);
   assert(MA.Id != 0);
 
@@ -522,13 +524,13 @@ void CodeNode::removeMember(Node NA, const DataFlowGraph &G) {
 }
 
 // Return the list of all members of the code node.
-NodeList CodeNode::members(const DataFlowGraph &G) const {
+auto CodeNode::members(const DataFlowGraph &G) const -> NodeList {
   static auto True = [](Node) -> bool { return true; };
   return members_if(True, G);
 }
 
 // Return the owner of the given instr node.
-Node InstrNode::getOwner(const DataFlowGraph &G) {
+auto InstrNode::getOwner(const DataFlowGraph &G) -> Node {
   Node NA = G.addr<NodeBase *>(getNext());
 
   while (NA.Addr != this) {
@@ -541,7 +543,7 @@ Node InstrNode::getOwner(const DataFlowGraph &G) {
 }
 
 // Add the phi node PA to the given block node.
-void BlockNode::addPhi(Phi PA, const DataFlowGraph &G) {
+auto BlockNode::addPhi(Phi PA, const DataFlowGraph &G) -> void {
   Node M = getFirstMember(G);
   if (M.Id == 0) {
     addMember(PA, G);
@@ -571,8 +573,8 @@ void BlockNode::addPhi(Phi PA, const DataFlowGraph &G) {
 
 // Find the block node corresponding to the machine basic block BB in the
 // given func node.
-Block FuncNode::findBlock(const MachineBasicBlock *BB,
-                          const DataFlowGraph &G) const {
+auto FuncNode::findBlock(const MachineBasicBlock *BB,
+                         const DataFlowGraph &G) const -> Block {
   auto EqBB = [BB](Node NA) -> bool { return Block(NA).Addr->getCode() == BB; };
   NodeList Ms = members_if(EqBB, G);
   if (!Ms.empty())
@@ -581,7 +583,7 @@ Block FuncNode::findBlock(const MachineBasicBlock *BB,
 }
 
 // Get the block node for the entry block in the given function.
-Block FuncNode::getEntryBlock(const DataFlowGraph &G) {
+auto FuncNode::getEntryBlock(const DataFlowGraph &G) -> Block {
   MachineBasicBlock *EntryB = &getCode()->front();
   return findBlock(EntryB, G);
 }
@@ -591,14 +593,14 @@ Block FuncNode::getEntryBlock(const DataFlowGraph &G) {
 
 // For a given instruction, check if there are any bits of RR that can remain
 // unchanged across this def.
-bool TargetOperandInfo::isPreserving(const MachineInstr &In,
-                                     unsigned OpNum) const {
+auto TargetOperandInfo::isPreserving(const MachineInstr &In,
+                                     unsigned OpNum) const -> bool {
   return TII.isPredicated(In);
 }
 
 // Check if the definition of RR produces an unspecified value.
-bool TargetOperandInfo::isClobbering(const MachineInstr &In,
-                                     unsigned OpNum) const {
+auto TargetOperandInfo::isClobbering(const MachineInstr &In,
+                                     unsigned OpNum) const -> bool {
   const MachineOperand &Op = In.getOperand(OpNum);
   if (Op.isRegMask())
     return true;
@@ -610,8 +612,8 @@ bool TargetOperandInfo::isClobbering(const MachineInstr &In,
 }
 
 // Check if the given instruction specifically requires
-bool TargetOperandInfo::isFixedReg(const MachineInstr &In,
-                                   unsigned OpNum) const {
+auto TargetOperandInfo::isFixedReg(const MachineInstr &In, unsigned OpNum) const
+    -> bool {
   if (In.isCall() || In.isReturn() || In.isInlineAsm())
     return true;
   // Check for a tail call.
@@ -676,7 +678,7 @@ DataFlowGraph::DefStack::Iterator::Iterator(const DataFlowGraph::DefStack &S,
 }
 
 // Return the size of the stack, including block delimiters.
-unsigned DataFlowGraph::DefStack::size() const {
+auto DataFlowGraph::DefStack::size() const -> unsigned {
   unsigned S = 0;
   for (auto I = top(), E = bottom(); I != E; I.down())
     S++;
@@ -686,14 +688,14 @@ unsigned DataFlowGraph::DefStack::size() const {
 // Remove the top entry from the stack. Remove all intervening delimiters
 // so that after this, the stack is either empty, or the top of the stack
 // is a non-delimiter.
-void DataFlowGraph::DefStack::pop() {
+auto DataFlowGraph::DefStack::pop() -> void {
   assert(!empty());
   unsigned P = nextDown(Stack.size());
   Stack.resize(P);
 }
 
 // Push a delimiter for block node N on the stack.
-void DataFlowGraph::DefStack::start_block(NodeId N) {
+auto DataFlowGraph::DefStack::start_block(NodeId N) -> void {
   assert(N != 0);
   Stack.push_back(Def(nullptr, N));
 }
@@ -701,7 +703,7 @@ void DataFlowGraph::DefStack::start_block(NodeId N) {
 // Remove all nodes from the top of the stack, until the delimited for
 // block node N is encountered. Remove the delimiter as well. In effect,
 // this will remove from the stack all definitions from block N.
-void DataFlowGraph::DefStack::clear_block(NodeId N) {
+auto DataFlowGraph::DefStack::clear_block(NodeId N) -> void {
   assert(N != 0);
   unsigned P = Stack.size();
   while (P > 0) {
@@ -715,7 +717,7 @@ void DataFlowGraph::DefStack::clear_block(NodeId N) {
 }
 
 // Move the stack iterator up by one.
-unsigned DataFlowGraph::DefStack::nextUp(unsigned P) const {
+auto DataFlowGraph::DefStack::nextUp(unsigned P) const -> unsigned {
   // Get the next valid position after P (skipping all delimiters).
   // The input position P does not have to point to a non-delimiter.
   unsigned SS = Stack.size();
@@ -730,7 +732,7 @@ unsigned DataFlowGraph::DefStack::nextUp(unsigned P) const {
 }
 
 // Move the stack iterator down by one.
-unsigned DataFlowGraph::DefStack::nextDown(unsigned P) const {
+auto DataFlowGraph::DefStack::nextDown(unsigned P) const -> unsigned {
   // Get the preceding valid position before P (skipping all delimiters).
   // The input position P does not have to point to a non-delimiter.
   assert(P > 0 && P <= Stack.size());
@@ -746,7 +748,7 @@ unsigned DataFlowGraph::DefStack::nextDown(unsigned P) const {
 
 // Register information.
 
-RegisterAggr DataFlowGraph::getLandingPadLiveIns() const {
+auto DataFlowGraph::getLandingPadLiveIns() const -> RegisterAggr {
   RegisterAggr LR(getPRI());
   const Function &F = MF.getFunction();
   const Constant *PF = F.hasPersonalityFn() ? F.getPersonalityFn() : nullptr;
@@ -763,21 +765,21 @@ RegisterAggr DataFlowGraph::getLandingPadLiveIns() const {
 // Node management functions.
 
 // Get the pointer to the node with the id N.
-NodeBase *DataFlowGraph::ptr(NodeId N) const {
+auto DataFlowGraph::ptr(NodeId N) const -> NodeBase * {
   if (N == 0)
     return nullptr;
   return Memory.ptr(N);
 }
 
 // Get the id of the node at the address P.
-NodeId DataFlowGraph::id(const NodeBase *P) const {
+auto DataFlowGraph::id(const NodeBase *P) const -> NodeId {
   if (P == nullptr)
     return 0;
   return Memory.id(P);
 }
 
 // Allocate a new node and set the attributes to Attrs.
-Node DataFlowGraph::newNode(uint16_t Attrs) {
+auto DataFlowGraph::newNode(uint16_t Attrs) -> Node {
   Node P = Memory.New();
   P.Addr->init();
   P.Addr->setAttrs(Attrs);
@@ -786,7 +788,7 @@ Node DataFlowGraph::newNode(uint16_t Attrs) {
 
 // Make a copy of the given node B, except for the data-flow links, which
 // are set to 0.
-Node DataFlowGraph::cloneNode(const Node B) {
+auto DataFlowGraph::cloneNode(const Node B) -> Node {
   Node NA = newNode(0);
   memcpy(NA.Addr, B.Addr, sizeof(NodeBase));
   // Ref nodes need to have the data-flow links reset.
@@ -805,14 +807,15 @@ Node DataFlowGraph::cloneNode(const Node B) {
 
 // Allocation routines for specific node types/kinds.
 
-Use DataFlowGraph::newUse(Instr Owner, MachineOperand &Op, uint16_t Flags) {
+auto DataFlowGraph::newUse(Instr Owner, MachineOperand &Op, uint16_t Flags)
+    -> Use {
   Use UA = newNode(NodeAttrs::Ref | NodeAttrs::Use | Flags);
   UA.Addr->setRegRef(&Op, *this);
   return UA;
 }
 
-PhiUse DataFlowGraph::newPhiUse(Phi Owner, RegisterRef RR, Block PredB,
-                                uint16_t Flags) {
+auto DataFlowGraph::newPhiUse(Phi Owner, RegisterRef RR, Block PredB,
+                              uint16_t Flags) -> PhiUse {
   PhiUse PUA = newNode(NodeAttrs::Ref | NodeAttrs::Use | Flags);
   assert(Flags & NodeAttrs::PhiRef);
   PUA.Addr->setRegRef(RR, *this);
@@ -820,47 +823,48 @@ PhiUse DataFlowGraph::newPhiUse(Phi Owner, RegisterRef RR, Block PredB,
   return PUA;
 }
 
-Def DataFlowGraph::newDef(Instr Owner, MachineOperand &Op, uint16_t Flags) {
+auto DataFlowGraph::newDef(Instr Owner, MachineOperand &Op, uint16_t Flags)
+    -> Def {
   Def DA = newNode(NodeAttrs::Ref | NodeAttrs::Def | Flags);
   DA.Addr->setRegRef(&Op, *this);
   return DA;
 }
 
-Def DataFlowGraph::newDef(Instr Owner, RegisterRef RR, uint16_t Flags) {
+auto DataFlowGraph::newDef(Instr Owner, RegisterRef RR, uint16_t Flags) -> Def {
   Def DA = newNode(NodeAttrs::Ref | NodeAttrs::Def | Flags);
   assert(Flags & NodeAttrs::PhiRef);
   DA.Addr->setRegRef(RR, *this);
   return DA;
 }
 
-Phi DataFlowGraph::newPhi(Block Owner) {
+auto DataFlowGraph::newPhi(Block Owner) -> Phi {
   Phi PA = newNode(NodeAttrs::Code | NodeAttrs::Phi);
   Owner.Addr->addPhi(PA, *this);
   return PA;
 }
 
-Stmt DataFlowGraph::newStmt(Block Owner, MachineInstr *MI) {
+auto DataFlowGraph::newStmt(Block Owner, MachineInstr *MI) -> Stmt {
   Stmt SA = newNode(NodeAttrs::Code | NodeAttrs::Stmt);
   SA.Addr->setCode(MI);
   Owner.Addr->addMember(SA, *this);
   return SA;
 }
 
-Block DataFlowGraph::newBlock(Func Owner, MachineBasicBlock *BB) {
+auto DataFlowGraph::newBlock(Func Owner, MachineBasicBlock *BB) -> Block {
   Block BA = newNode(NodeAttrs::Code | NodeAttrs::Block);
   BA.Addr->setCode(BB);
   Owner.Addr->addMember(BA, *this);
   return BA;
 }
 
-Func DataFlowGraph::newFunc(MachineFunction *MF) {
+auto DataFlowGraph::newFunc(MachineFunction *MF) -> Func {
   Func FA = newNode(NodeAttrs::Code | NodeAttrs::Func);
   FA.Addr->setCode(MF);
   return FA;
 }
 
 // Build the data flow graph.
-void DataFlowGraph::build(unsigned Options) {
+auto DataFlowGraph::build(unsigned Options) -> void {
   reset();
   TheFunc = newFunc(&MF);
 
@@ -956,7 +960,8 @@ void DataFlowGraph::build(unsigned Options) {
     removeUnusedPhis();
 }
 
-RegisterRef DataFlowGraph::makeRegRef(unsigned Reg, unsigned Sub) const {
+auto DataFlowGraph::makeRegRef(unsigned Reg, unsigned Sub) const
+    -> RegisterRef {
   assert(RegisterRef::isRegId(Reg) || RegisterRef::isMaskId(Reg));
   assert(Reg != 0);
   if (Sub != 0)
@@ -964,7 +969,7 @@ RegisterRef DataFlowGraph::makeRegRef(unsigned Reg, unsigned Sub) const {
   return RegisterRef(Reg);
 }
 
-RegisterRef DataFlowGraph::makeRegRef(const MachineOperand &Op) const {
+auto DataFlowGraph::makeRegRef(const MachineOperand &Op) const -> RegisterRef {
   assert(Op.isReg() || Op.isRegMask());
   if (Op.isReg())
     return makeRegRef(Op.getReg(), Op.getSubReg());
@@ -973,14 +978,14 @@ RegisterRef DataFlowGraph::makeRegRef(const MachineOperand &Op) const {
 }
 
 // For each stack in the map DefM, push the delimiter for block B on it.
-void DataFlowGraph::markBlock(NodeId B, DefStackMap &DefM) {
+auto DataFlowGraph::markBlock(NodeId B, DefStackMap &DefM) -> void {
   // Push block delimiters.
   for (auto &P : DefM)
     P.second.start_block(B);
 }
 
 // Remove all definitions coming from block B from each stack in DefM.
-void DataFlowGraph::releaseBlock(NodeId B, DefStackMap &DefM) {
+auto DataFlowGraph::releaseBlock(NodeId B, DefStackMap &DefM) -> void {
   // Pop all defs from this block from the definition stack. Defs that were
   // added to the map during the traversal of instructions will not have a
   // delimiter, but for those, the whole stack will be emptied.
@@ -998,14 +1003,14 @@ void DataFlowGraph::releaseBlock(NodeId B, DefStackMap &DefM) {
 
 // Push all definitions from the instruction node IA to an appropriate
 // stack in DefM.
-void DataFlowGraph::pushAllDefs(Instr IA, DefStackMap &DefM) {
+auto DataFlowGraph::pushAllDefs(Instr IA, DefStackMap &DefM) -> void {
   pushClobbers(IA, DefM);
   pushDefs(IA, DefM);
 }
 
 // Push all definitions from the instruction node IA to an appropriate
 // stack in DefM.
-void DataFlowGraph::pushClobbers(Instr IA, DefStackMap &DefM) {
+auto DataFlowGraph::pushClobbers(Instr IA, DefStackMap &DefM) -> void {
   NodeSet Visited;
   std::set<RegisterId> Defined;
 
@@ -1049,7 +1054,7 @@ void DataFlowGraph::pushClobbers(Instr IA, DefStackMap &DefM) {
 
 // Push all definitions from the instruction node IA to an appropriate
 // stack in DefM.
-void DataFlowGraph::pushDefs(Instr IA, DefStackMap &DefM) {
+auto DataFlowGraph::pushDefs(Instr IA, DefStackMap &DefM) -> void {
   NodeSet Visited;
 #ifndef NDEBUG
   std::set<RegisterId> Defined;
@@ -1103,7 +1108,7 @@ void DataFlowGraph::pushDefs(Instr IA, DefStackMap &DefM) {
 
 // Return the list of all reference nodes related to RA, including RA itself.
 // See "getNextRelated" for the meaning of a "related reference".
-NodeList DataFlowGraph::getRelatedRefs(Instr IA, Ref RA) const {
+auto DataFlowGraph::getRelatedRefs(Instr IA, Ref RA) const -> NodeList {
   assert(IA.Id != 0 && RA.Id != 0);
 
   NodeList Refs;
@@ -1116,7 +1121,7 @@ NodeList DataFlowGraph::getRelatedRefs(Instr IA, Ref RA) const {
 }
 
 // Clear all information in the graph.
-void DataFlowGraph::reset() {
+auto DataFlowGraph::reset() -> void {
   Memory.clear();
   BlockNodes.clear();
   TheFunc = Func();
@@ -1128,7 +1133,7 @@ void DataFlowGraph::reset() {
 // characteristics. Specific examples of related nodes are shadow reference
 // nodes.
 // Return the equivalent of nullptr if there are no more related references.
-Ref DataFlowGraph::getNextRelated(Instr IA, Ref RA) const {
+auto DataFlowGraph::getNextRelated(Instr IA, Ref RA) const -> Ref {
   assert(IA.Id != 0 && RA.Id != 0);
 
   auto Related = [this, RA](Ref TA) -> bool {
@@ -1166,8 +1171,8 @@ Ref DataFlowGraph::getNextRelated(Instr IA, Ref RA) const {
 // first element is the element after which such a node should be inserted,
 // and the second element is a null-address.
 template <typename Predicate>
-std::pair<Ref, Ref> DataFlowGraph::locateNextRef(Instr IA, Ref RA,
-                                                 Predicate P) const {
+auto DataFlowGraph::locateNextRef(Instr IA, Ref RA, Predicate P) const
+    -> std::pair<Ref, Ref> {
   assert(IA.Id != 0 && RA.Id != 0);
 
   Ref NA;
@@ -1188,7 +1193,7 @@ std::pair<Ref, Ref> DataFlowGraph::locateNextRef(Instr IA, Ref RA,
 
 // Get the next shadow node in IA corresponding to RA, and optionally create
 // such a node if it does not exist.
-Ref DataFlowGraph::getNextShadow(Instr IA, Ref RA, bool Create) {
+auto DataFlowGraph::getNextShadow(Instr IA, Ref RA, bool Create) -> Ref {
   assert(IA.Id != 0 && RA.Id != 0);
 
   uint16_t Flags = RA.Addr->getFlags() | NodeAttrs::Shadow;
@@ -1208,7 +1213,7 @@ Ref DataFlowGraph::getNextShadow(Instr IA, Ref RA, bool Create) {
 
 // Get the next shadow node in IA corresponding to RA. Return null-address
 // if such a node does not exist.
-Ref DataFlowGraph::getNextShadow(Instr IA, Ref RA) const {
+auto DataFlowGraph::getNextShadow(Instr IA, Ref RA) const -> Ref {
   assert(IA.Id != 0 && RA.Id != 0);
   uint16_t Flags = RA.Addr->getFlags() | NodeAttrs::Shadow;
   auto IsShadow = [Flags](Ref TA) -> bool {
@@ -1219,7 +1224,7 @@ Ref DataFlowGraph::getNextShadow(Instr IA, Ref RA) const {
 
 // Create a new statement node in the block node BA that corresponds to
 // the machine instruction MI.
-void DataFlowGraph::buildStmt(Block BA, MachineInstr &In) {
+auto DataFlowGraph::buildStmt(Block BA, MachineInstr &In) -> void {
   Stmt SA = newStmt(BA, &In);
 
   auto isCall = [](const MachineInstr &In) -> bool {
@@ -1353,7 +1358,7 @@ void DataFlowGraph::buildStmt(Block BA, MachineInstr &In) {
 
 // Scan all defs in the block node BA and record in PhiM the locations of
 // phi nodes corresponding to these defs.
-void DataFlowGraph::recordDefsForDF(BlockRefsMap &PhiM, Block BA) {
+auto DataFlowGraph::recordDefsForDF(BlockRefsMap &PhiM, Block BA) -> void {
   // Check all defs from block BA and record them in each block in BA's
   // iterated dominance frontier. This information will later be used to
   // create phi nodes.
@@ -1392,8 +1397,8 @@ void DataFlowGraph::recordDefsForDF(BlockRefsMap &PhiM, Block BA) {
 
 // Given the locations of phi nodes in the map PhiM, create the phi nodes
 // that are located in the block node BA.
-void DataFlowGraph::buildPhis(BlockRefsMap &PhiM, RegisterSet &AllRefs,
-                              Block BA) {
+auto DataFlowGraph::buildPhis(BlockRefsMap &PhiM, RegisterSet &AllRefs,
+                              Block BA) -> void {
   // Check if this blocks has any DF defs, i.e. if there are any defs
   // that this block is in the iterated dominance frontier of.
   auto HasDF = PhiM.find(BA.Id);
@@ -1421,7 +1426,7 @@ void DataFlowGraph::buildPhis(BlockRefsMap &PhiM, RegisterSet &AllRefs,
 }
 
 // Remove any unneeded phi nodes that were created during the build process.
-void DataFlowGraph::removeUnusedPhis() {
+auto DataFlowGraph::removeUnusedPhis() -> void {
   // This will remove unused phis, i.e. phis where each def does not reach
   // any uses or other defs. This will not detect or remove circular phi
   // chains that are otherwise dead. Unused/dead phis are created during
@@ -1475,7 +1480,7 @@ void DataFlowGraph::removeUnusedPhis() {
 // reaching def of TA to the appropriate def node. Create any shadow nodes
 // as appropriate.
 template <typename T>
-void DataFlowGraph::linkRefUp(Instr IA, NodeAddr<T> TA, DefStack &DS) {
+auto DataFlowGraph::linkRefUp(Instr IA, NodeAddr<T> TA, DefStack &DS) -> void {
   if (DS.empty())
     return;
   RegisterRef RR = TA.Addr->getRegRef(*this);
@@ -1519,7 +1524,8 @@ void DataFlowGraph::linkRefUp(Instr IA, NodeAddr<T> TA, DefStack &DS) {
 
 // Create data-flow links for all reference nodes in the statement node SA.
 template <typename Predicate>
-void DataFlowGraph::linkStmtRefs(DefStackMap &DefM, Stmt SA, Predicate P) {
+auto DataFlowGraph::linkStmtRefs(DefStackMap &DefM, Stmt SA, Predicate P)
+    -> void {
 #ifndef NDEBUG
   RegisterSet Defs(getPRI());
 #endif
@@ -1550,7 +1556,7 @@ void DataFlowGraph::linkStmtRefs(DefStackMap &DefM, Stmt SA, Predicate P) {
 
 // Create data-flow links for all instructions in the block node BA. This
 // will include updating any phi nodes in BA.
-void DataFlowGraph::linkBlockRefs(DefStackMap &DefM, Block BA) {
+auto DataFlowGraph::linkBlockRefs(DefStackMap &DefM, Block BA) -> void {
   // Push block delimiters.
   markBlock(BA.Id, DefM);
 
@@ -1628,7 +1634,7 @@ void DataFlowGraph::linkBlockRefs(DefStackMap &DefM, Block BA) {
 }
 
 // Remove the use node UA from any data-flow and structural links.
-void DataFlowGraph::unlinkUseDF(Use UA) {
+auto DataFlowGraph::unlinkUseDF(Use UA) -> void {
   NodeId RD = UA.Addr->getReachingDef();
   NodeId Sib = UA.Addr->getSibling();
 
@@ -1655,7 +1661,7 @@ void DataFlowGraph::unlinkUseDF(Use UA) {
 }
 
 // Remove the def node DA from any data-flow and structural links.
-void DataFlowGraph::unlinkDefDF(Def DA) {
+auto DataFlowGraph::unlinkDefDF(Def DA) -> void {
   //
   //         RD
   //         | reached