Subzero: Use 'override' as appropriate for C++11.

src/IceInst.h

 //===- subzero/src/IceInst.h - High-level instructions ----------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file declares the Inst class and its target-independent
@@ skipping 12 matching lines @@
 
 // TODO: The Cfg structure, and instructions in particular, need to be
 // validated for things like valid operand types, valid branch
 // targets, proper ordering of Phi and non-Phi instructions, etc.
 // Most of the validity checking will be done in the bitcode reader.
 // We need a list of everything that should be validated, and tests
 // for each.
 
 namespace Ice {
 
+// Base instruction class for ICE.  Inst has two subclasses:
+// InstHighLevel and InstTarget.  High-level ICE instructions inherit
+// from InstHighLevel, and low-level (target-specific) ICE
+// instructions inherit from InstTarget.
 class Inst {
 public:
   enum InstKind {
     // Arbitrary (alphabetical) order, except put Unreachable first.
     Unreachable,
     Alloca,
     Arithmetic,
     Assign, // not part of LLVM/PNaCl bitcode
     Br,
     Call,
@@ skipping 53 matching lines @@
 
   void livenessLightweight(Cfg *Func, llvm::BitVector &Live);
   void liveness(InstNumberT InstNumber, llvm::BitVector &Live,
                 Liveness *Liveness, const CfgNode *Node);
 
   // Get the number of native instructions that this instruction
   // ultimately emits.  By default, high-level instructions don't
   // result in any native instructions, and a target-specific
   // instruction results in a single native instruction.
   virtual uint32_t getEmitInstCount() const { return 0; }
-  virtual void emit(const Cfg *Func) const;
-  virtual void emitIAS(const Cfg *Func) const;
+  virtual void emit(const Cfg *Func) const = 0;
+  virtual void emitIAS(const Cfg *Func) const = 0;
   virtual void dump(const Cfg *Func) const;
   virtual void dumpExtras(const Cfg *Func) const;
   void dumpDecorated(const Cfg *Func) const;
   void emitSources(const Cfg *Func) const;
   void dumpSources(const Cfg *Func) const;
   void dumpDest(const Cfg *Func) const;
   virtual bool isRedundantAssign() const { return false; }
 
   virtual ~Inst() {}
 
@@ skipping 40 matching lines @@
   // Only the first CHAR_BIT * sizeof(LREndedBits) variables are
   // tracked this way.
   typedef uint32_t LREndedBits; // only first 32 src operands tracked, sorry
   LREndedBits LiveRangesEnded;
 
 private:
   Inst(const Inst &) LLVM_DELETED_FUNCTION;
   Inst &operator=(const Inst &) LLVM_DELETED_FUNCTION;
 };
 
+class InstHighLevel : public Inst {
+  InstHighLevel(const InstHighLevel &) LLVM_DELETED_FUNCTION;
+  InstHighLevel &operator=(const InstHighLevel &) LLVM_DELETED_FUNCTION;
+
+protected:
+  InstHighLevel(Cfg *Func, InstKind Kind, SizeT MaxSrcs, Variable *Dest)
+      : Inst(Func, Kind, MaxSrcs, Dest) {}
+  void emit(const Cfg * /*Func*/) const override {
+    llvm_unreachable("emit() called on a non-lowered instruction");
+  }
+  void emitIAS(const Cfg * /*Func*/) const override {
+    llvm_unreachable("emitIAS() called on a non-lowered instruction");
+  }
+  ~InstHighLevel() override {}
+};
+
 // Alloca instruction.  This captures the size in bytes as getSrc(0),
 // and the required alignment in bytes.  The alignment must be either
 // 0 (no alignment required) or a power of 2.
-class InstAlloca : public Inst {
+class InstAlloca : public InstHighLevel {
 public:
   static InstAlloca *create(Cfg *Func, Operand *ByteCount,
                             uint32_t AlignInBytes, Variable *Dest) {
     return new (Func->allocateInst<InstAlloca>())
         InstAlloca(Func, ByteCount, AlignInBytes, Dest);
   }
   uint32_t getAlignInBytes() const { return AlignInBytes; }
   Operand *getSizeInBytes() const { return getSrc(0); }
-  virtual void dump(const Cfg *Func) const;
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return Inst->getKind() == Alloca; }
 
 private:
   InstAlloca(Cfg *Func, Operand *ByteCount, uint32_t AlignInBytes,
              Variable *Dest);
   InstAlloca(const InstAlloca &) LLVM_DELETED_FUNCTION;
   InstAlloca &operator=(const InstAlloca &) LLVM_DELETED_FUNCTION;
-  virtual ~InstAlloca() {}
+  ~InstAlloca() override {}
   const uint32_t AlignInBytes;
 };
 
 // Binary arithmetic instruction.  The source operands are captured in
 // getSrc(0) and getSrc(1).
-class InstArithmetic : public Inst {
+class InstArithmetic : public InstHighLevel {
 public:
   enum OpKind {
 #define X(tag, str, commutative) tag,
     ICEINSTARITHMETIC_TABLE
 #undef X
         _num
   };
 
   static InstArithmetic *create(Cfg *Func, OpKind Op, Variable *Dest,
                                 Operand *Source1, Operand *Source2) {
     return new (Func->allocateInst<InstArithmetic>())
         InstArithmetic(Func, Op, Dest, Source1, Source2);
   }
   OpKind getOp() const { return Op; }
   static const char *getOpName(OpKind Op);
   bool isCommutative() const;
-  virtual void dump(const Cfg *Func) const;
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) {
     return Inst->getKind() == Arithmetic;
   }
 
 private:
   InstArithmetic(Cfg *Func, OpKind Op, Variable *Dest, Operand *Source1,
                  Operand *Source2);
   InstArithmetic(const InstArithmetic &) LLVM_DELETED_FUNCTION;
   InstArithmetic &operator=(const InstArithmetic &) LLVM_DELETED_FUNCTION;
-  virtual ~InstArithmetic() {}
+  ~InstArithmetic() override {}
 
   const OpKind Op;
 };
 
 // Assignment instruction.  The source operand is captured in
 // getSrc(0).  This is not part of the LLVM bitcode, but is a useful
 // abstraction for some of the lowering.  E.g., if Phi instruction
 // lowering happens before target lowering, or for representing an
 // Inttoptr instruction, or as an intermediate step for lowering a
 // Load instruction.
-class InstAssign : public Inst {
+class InstAssign : public InstHighLevel {
 public:
   static InstAssign *create(Cfg *Func, Variable *Dest, Operand *Source) {
     return new (Func->allocateInst<InstAssign>())
         InstAssign(Func, Dest, Source);
   }
-  virtual bool isSimpleAssign() const { return true; }
-  virtual void dump(const Cfg *Func) const;
+  bool isSimpleAssign() const override { return true; }
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return Inst->getKind() == Assign; }
 
 private:
   InstAssign(Cfg *Func, Variable *Dest, Operand *Source);
   InstAssign(const InstAssign &) LLVM_DELETED_FUNCTION;
   InstAssign &operator=(const InstAssign &) LLVM_DELETED_FUNCTION;
-  virtual ~InstAssign() {}
+  ~InstAssign() override {}
 };
 
 // Branch instruction.  This represents both conditional and
 // unconditional branches.
-class InstBr : public Inst {
+class InstBr : public InstHighLevel {
 public:
   // Create a conditional branch.  If TargetTrue==TargetFalse, it is
   // optimized to an unconditional branch.
   static InstBr *create(Cfg *Func, Operand *Source, CfgNode *TargetTrue,
                         CfgNode *TargetFalse) {
     return new (Func->allocateInst<InstBr>())
         InstBr(Func, Source, TargetTrue, TargetFalse);
   }
   // Create an unconditional branch.
   static InstBr *create(Cfg *Func, CfgNode *Target) {
     return new (Func->allocateInst<InstBr>()) InstBr(Func, Target);
   }
   bool isUnconditional() const { return getTargetTrue() == NULL; }
   Operand *getCondition() const {
     assert(!isUnconditional());
     return getSrc(0);
   }
   CfgNode *getTargetTrue() const { return TargetTrue; }
   CfgNode *getTargetFalse() const { return TargetFalse; }
   CfgNode *getTargetUnconditional() const {
     assert(isUnconditional());
     return getTargetFalse();
   }
-  virtual NodeList getTerminatorEdges() const;
-  virtual void dump(const Cfg *Func) const;
+  NodeList getTerminatorEdges() const override;
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return Inst->getKind() == Br; }
 
 private:
   // Conditional branch
   InstBr(Cfg *Func, Operand *Source, CfgNode *TargetTrue, CfgNode *TargetFalse);
   // Unconditional branch
   InstBr(Cfg *Func, CfgNode *Target);
   InstBr(const InstBr &) LLVM_DELETED_FUNCTION;
   InstBr &operator=(const InstBr &) LLVM_DELETED_FUNCTION;
-  virtual ~InstBr() {}
+  ~InstBr() override {}
 
   CfgNode *const TargetFalse; // Doubles as unconditional branch target
   CfgNode *const TargetTrue;  // NULL if unconditional branch
 };
 
 // Call instruction.  The call target is captured as getSrc(0), and
 // arg I is captured as getSrc(I+1).
-class InstCall : public Inst {
+class InstCall : public InstHighLevel {
 public:
   static InstCall *create(Cfg *Func, SizeT NumArgs, Variable *Dest,
                           Operand *CallTarget, bool HasTailCall) {
     // Set HasSideEffects to true so that the call instruction can't be
     // dead-code eliminated. IntrinsicCalls can override this if the
     // particular intrinsic is deletable and has no side-effects.
     const bool HasSideEffects = true;
     const InstKind Kind = Inst::Call;
     return new (Func->allocateInst<InstCall>()) InstCall(
         Func, NumArgs, Dest, CallTarget, HasTailCall, HasSideEffects, Kind);
   }
   void addArg(Operand *Arg) { addSource(Arg); }
   Operand *getCallTarget() const { return getSrc(0); }
   Operand *getArg(SizeT I) const { return getSrc(I + 1); }
   SizeT getNumArgs() const { return getSrcSize() - 1; }
   bool isTailcall() const { return HasTailCall; }
-  virtual void dump(const Cfg *Func) const;
+  void dump(const Cfg *Func) const;
   static bool classof(const Inst *Inst) { return Inst->getKind() == Call; }
   Type getReturnType() const;
 
 protected:
   InstCall(Cfg *Func, SizeT NumArgs, Variable *Dest, Operand *CallTarget,
            bool HasTailCall, bool HasSideEff, InstKind Kind)
-      : Inst(Func, Kind, NumArgs + 1, Dest),
-        HasTailCall(HasTailCall) {
+      : InstHighLevel(Func, Kind, NumArgs + 1, Dest), HasTailCall(HasTailCall) {
     HasSideEffects = HasSideEff;
     addSource(CallTarget);
   }
-  virtual ~InstCall() {}
+  ~InstCall() override {}
 
 private:
   bool HasTailCall;
   InstCall(const InstCall &) LLVM_DELETED_FUNCTION;
   InstCall &operator=(const InstCall &) LLVM_DELETED_FUNCTION;
 };
 
 // Cast instruction (a.k.a. conversion operation).
-class InstCast : public Inst {
+class InstCast : public InstHighLevel {
 public:
   enum OpKind {
 #define X(tag, str) tag,
     ICEINSTCAST_TABLE
 #undef X
         _num
   };
 
   static InstCast *create(Cfg *Func, OpKind CastKind, Variable *Dest,
                           Operand *Source) {
     return new (Func->allocateInst<InstCast>())
         InstCast(Func, CastKind, Dest, Source);
   }
   OpKind getCastKind() const { return CastKind; }
-  virtual void dump(const Cfg *Func) const;
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return Inst->getKind() == Cast; }
 
 private:
   InstCast(Cfg *Func, OpKind CastKind, Variable *Dest, Operand *Source);
   InstCast(const InstCast &) LLVM_DELETED_FUNCTION;
   InstCast &operator=(const InstCast &) LLVM_DELETED_FUNCTION;
-  virtual ~InstCast() {}
+  ~InstCast() override {}
   const OpKind CastKind;
 };
 
 // ExtractElement instruction.
-class InstExtractElement : public Inst {
+class InstExtractElement : public InstHighLevel {
 public:
   static InstExtractElement *create(Cfg *Func, Variable *Dest, Operand *Source1,
                                     Operand *Source2) {
     return new (Func->allocateInst<InstExtractElement>())
         InstExtractElement(Func, Dest, Source1, Source2);
   }
 
-  virtual void dump(const Cfg *Func) const;
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) {
     return Inst->getKind() == ExtractElement;
   }
 
 private:
   InstExtractElement(Cfg *Func, Variable *Dest, Operand *Source1,
                      Operand *Source2);
   InstExtractElement(const InstExtractElement &) LLVM_DELETED_FUNCTION;
   InstExtractElement &
   operator=(const InstExtractElement &) LLVM_DELETED_FUNCTION;
-  virtual ~InstExtractElement() {}
+  ~InstExtractElement() override {}
 };
 
 // Floating-point comparison instruction.  The source operands are
 // captured in getSrc(0) and getSrc(1).
-class InstFcmp : public Inst {
+class InstFcmp : public InstHighLevel {
 public:
   enum FCond {
 #define X(tag, str) tag,
     ICEINSTFCMP_TABLE
 #undef X
         _num
   };
 
   static InstFcmp *create(Cfg *Func, FCond Condition, Variable *Dest,
                           Operand *Source1, Operand *Source2) {
     return new (Func->allocateInst<InstFcmp>())
         InstFcmp(Func, Condition, Dest, Source1, Source2);
   }
   FCond getCondition() const { return Condition; }
-  virtual void dump(const Cfg *Func) const;
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return Inst->getKind() == Fcmp; }
 
 private:
   InstFcmp(Cfg *Func, FCond Condition, Variable *Dest, Operand *Source1,
            Operand *Source2);
   InstFcmp(const InstFcmp &) LLVM_DELETED_FUNCTION;
   InstFcmp &operator=(const InstFcmp &) LLVM_DELETED_FUNCTION;
-  virtual ~InstFcmp() {}
+  ~InstFcmp() override {}
   const FCond Condition;
 };
 
 // Integer comparison instruction.  The source operands are captured
 // in getSrc(0) and getSrc(1).
-class InstIcmp : public Inst {
+class InstIcmp : public InstHighLevel {
 public:
   enum ICond {
 #define X(tag, str) tag,
     ICEINSTICMP_TABLE
 #undef X
         _num
   };
 
   static InstIcmp *create(Cfg *Func, ICond Condition, Variable *Dest,
                           Operand *Source1, Operand *Source2) {
     return new (Func->allocateInst<InstIcmp>())
         InstIcmp(Func, Condition, Dest, Source1, Source2);
   }
   ICond getCondition() const { return Condition; }
-  virtual void dump(const Cfg *Func) const;
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return Inst->getKind() == Icmp; }
 
 private:
   InstIcmp(Cfg *Func, ICond Condition, Variable *Dest, Operand *Source1,
            Operand *Source2);
   InstIcmp(const InstIcmp &) LLVM_DELETED_FUNCTION;
   InstIcmp &operator=(const InstIcmp &) LLVM_DELETED_FUNCTION;
-  virtual ~InstIcmp() {}
+  ~InstIcmp() override {}
   const ICond Condition;
 };
 
 // InsertElement instruction.
-class InstInsertElement : public Inst {
+class InstInsertElement : public InstHighLevel {
 public:
   static InstInsertElement *create(Cfg *Func, Variable *Dest, Operand *Source1,
                                    Operand *Source2, Operand *Source3) {
     return new (Func->allocateInst<InstInsertElement>())
         InstInsertElement(Func, Dest, Source1, Source2, Source3);
   }
 
-  virtual void dump(const Cfg *Func) const;
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) {
     return Inst->getKind() == InsertElement;
   }
 
 private:
   InstInsertElement(Cfg *Func, Variable *Dest, Operand *Source1,
                     Operand *Source2, Operand *Source3);
   InstInsertElement(const InstInsertElement &) LLVM_DELETED_FUNCTION;
   InstInsertElement &operator=(const InstInsertElement &) LLVM_DELETED_FUNCTION;
-  virtual ~InstInsertElement() {}
+  ~InstInsertElement() override {}
 };
 
 // Call to an intrinsic function.  The call target is captured as getSrc(0),
 // and arg I is captured as getSrc(I+1).
 class InstIntrinsicCall : public InstCall {
 public:
   static InstIntrinsicCall *create(Cfg *Func, SizeT NumArgs, Variable *Dest,
                                    Operand *CallTarget,
                                    const Intrinsics::IntrinsicInfo &Info) {
     return new (Func->allocateInst<InstIntrinsicCall>())
         InstIntrinsicCall(Func, NumArgs, Dest, CallTarget, Info);
   }
   static bool classof(const Inst *Inst) {
     return Inst->getKind() == IntrinsicCall;
   }
 
   Intrinsics::IntrinsicInfo getIntrinsicInfo() const { return Info; }
 
 private:
   InstIntrinsicCall(Cfg *Func, SizeT NumArgs, Variable *Dest,
                     Operand *CallTarget, const Intrinsics::IntrinsicInfo &Info)
       : InstCall(Func, NumArgs, Dest, CallTarget, false, Info.HasSideEffects,
                  Inst::IntrinsicCall),
         Info(Info) {}
   InstIntrinsicCall(const InstIntrinsicCall &) LLVM_DELETED_FUNCTION;
   InstIntrinsicCall &operator=(const InstIntrinsicCall &) LLVM_DELETED_FUNCTION;
-  virtual ~InstIntrinsicCall() {}
+  ~InstIntrinsicCall() override {}
   const Intrinsics::IntrinsicInfo Info;
 };
 
 // Load instruction.  The source address is captured in getSrc(0).
-class InstLoad : public Inst {
+class InstLoad : public InstHighLevel {
 public:
   static InstLoad *create(Cfg *Func, Variable *Dest, Operand *SourceAddr,
                           uint32_t align = 1) {
     // TODO(kschimpf) Stop ignoring alignment specification.
     (void)align;
     return new (Func->allocateInst<InstLoad>())
         InstLoad(Func, Dest, SourceAddr);
   }
   Operand *getSourceAddress() const { return getSrc(0); }
-  virtual void dump(const Cfg *Func) const;
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return Inst->getKind() == Load; }
 
 private:
   InstLoad(Cfg *Func, Variable *Dest, Operand *SourceAddr);
   InstLoad(const InstLoad &) LLVM_DELETED_FUNCTION;
   InstLoad &operator=(const InstLoad &) LLVM_DELETED_FUNCTION;
-  virtual ~InstLoad() {}
+  ~InstLoad() override {}
 };
 
 // Phi instruction.  For incoming edge I, the node is Labels[I] and
 // the Phi source operand is getSrc(I).
-class InstPhi : public Inst {
+class InstPhi : public InstHighLevel {
 public:
   static InstPhi *create(Cfg *Func, SizeT MaxSrcs, Variable *Dest) {
     return new (Func->allocateInst<InstPhi>()) InstPhi(Func, MaxSrcs, Dest);
   }
   void addArgument(Operand *Source, CfgNode *Label);
   Operand *getOperandForTarget(CfgNode *Target) const;
   void livenessPhiOperand(llvm::BitVector &Live, CfgNode *Target,
                           Liveness *Liveness);
   Inst *lower(Cfg *Func);
-  virtual void dump(const Cfg *Func) const;
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return Inst->getKind() == Phi; }
 
 private:
   InstPhi(Cfg *Func, SizeT MaxSrcs, Variable *Dest);
   InstPhi(const InstPhi &) LLVM_DELETED_FUNCTION;
   InstPhi &operator=(const InstPhi &) LLVM_DELETED_FUNCTION;
-  virtual void destroy(Cfg *Func) {
+  void destroy(Cfg *Func) override {
     Func->deallocateArrayOf<CfgNode *>(Labels);
     Inst::destroy(Func);
   }
-  virtual ~InstPhi() {}
+  ~InstPhi() override {}
 
   // Labels[] duplicates the InEdges[] information in the enclosing
   // CfgNode, but the Phi instruction is created before InEdges[]
   // is available, so it's more complicated to share the list.
   CfgNode **Labels;
 };
 
 // Ret instruction.  The return value is captured in getSrc(0), but if
 // there is no return value (void-type function), then
 // getSrcSize()==0 and hasRetValue()==false.
-class InstRet : public Inst {
+class InstRet : public InstHighLevel {
 public:
   static InstRet *create(Cfg *Func, Operand *RetValue = NULL) {
     return new (Func->allocateInst<InstRet>()) InstRet(Func, RetValue);
   }
   bool hasRetValue() const { return getSrcSize(); }
   Operand *getRetValue() const {
     assert(hasRetValue());
     return getSrc(0);
   }
-  virtual NodeList getTerminatorEdges() const { return NodeList(); }
-  virtual void dump(const Cfg *Func) const;
+  NodeList getTerminatorEdges() const override { return NodeList(); }
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return Inst->getKind() == Ret; }
 
 private:
   InstRet(Cfg *Func, Operand *RetValue);
   InstRet(const InstRet &) LLVM_DELETED_FUNCTION;
   InstRet &operator=(const InstRet &) LLVM_DELETED_FUNCTION;
-  virtual ~InstRet() {}
+  ~InstRet() override {}
 };
 
 // Select instruction.  The condition, true, and false operands are captured.
-class InstSelect : public Inst {
+class InstSelect : public InstHighLevel {
 public:
   static InstSelect *create(Cfg *Func, Variable *Dest, Operand *Condition,
                             Operand *SourceTrue, Operand *SourceFalse) {
     return new (Func->allocateInst<InstSelect>())
         InstSelect(Func, Dest, Condition, SourceTrue, SourceFalse);
   }
   Operand *getCondition() const { return getSrc(0); }
   Operand *getTrueOperand() const { return getSrc(1); }
   Operand *getFalseOperand() const { return getSrc(2); }
-  virtual void dump(const Cfg *Func) const;
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return Inst->getKind() == Select; }
 
 private:
   InstSelect(Cfg *Func, Variable *Dest, Operand *Condition, Operand *Source1,
              Operand *Source2);
   InstSelect(const InstSelect &) LLVM_DELETED_FUNCTION;
   InstSelect &operator=(const InstSelect &) LLVM_DELETED_FUNCTION;
-  virtual ~InstSelect() {}
+  ~InstSelect() override {}
 };
 
 // Store instruction.  The address operand is captured, along with the
 // data operand to be stored into the address.
-class InstStore : public Inst {
+class InstStore : public InstHighLevel {
 public:
   static InstStore *create(Cfg *Func, Operand *Data, Operand *Addr,
                            uint32_t align = 1) {
     // TODO(kschimpf) Stop ignoring alignment specification.
     (void)align;
     return new (Func->allocateInst<InstStore>()) InstStore(Func, Data, Addr);
   }
   Operand *getAddr() const { return getSrc(1); }
   Operand *getData() const { return getSrc(0); }
-  virtual void dump(const Cfg *Func) const;
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return Inst->getKind() == Store; }
 
 private:
   InstStore(Cfg *Func, Operand *Data, Operand *Addr);
   InstStore(const InstStore &) LLVM_DELETED_FUNCTION;
   InstStore &operator=(const InstStore &) LLVM_DELETED_FUNCTION;
-  virtual ~InstStore() {}
+  ~InstStore() override {}
 };
 
 // Switch instruction.  The single source operand is captured as
 // getSrc(0).
-class InstSwitch : public Inst {
+class InstSwitch : public InstHighLevel {
 public:
   static InstSwitch *create(Cfg *Func, SizeT NumCases, Operand *Source,
                             CfgNode *LabelDefault) {
     return new (Func->allocateInst<InstSwitch>())
         InstSwitch(Func, NumCases, Source, LabelDefault);
   }
   Operand *getComparison() const { return getSrc(0); }
   CfgNode *getLabelDefault() const { return LabelDefault; }
   SizeT getNumCases() const { return NumCases; }
   uint64_t getValue(SizeT I) const {
     assert(I < NumCases);
     return Values[I];
   }
   CfgNode *getLabel(SizeT I) const {
     assert(I < NumCases);
     return Labels[I];
   }
   void addBranch(SizeT CaseIndex, uint64_t Value, CfgNode *Label);
-  virtual NodeList getTerminatorEdges() const;
-  virtual void dump(const Cfg *Func) const;
+  NodeList getTerminatorEdges() const override;
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return Inst->getKind() == Switch; }
 
 private:
   InstSwitch(Cfg *Func, SizeT NumCases, Operand *Source, CfgNode *LabelDefault);
   InstSwitch(const InstSwitch &) LLVM_DELETED_FUNCTION;
   InstSwitch &operator=(const InstSwitch &) LLVM_DELETED_FUNCTION;
-  virtual void destroy(Cfg *Func) {
+  void destroy(Cfg *Func) override {
     Func->deallocateArrayOf<uint64_t>(Values);
     Func->deallocateArrayOf<CfgNode *>(Labels);
     Inst::destroy(Func);
   }
-  virtual ~InstSwitch() {}
+  ~InstSwitch() override {}
 
   CfgNode *LabelDefault;
   SizeT NumCases;   // not including the default case
   uint64_t *Values; // size is NumCases
   CfgNode **Labels; // size is NumCases
 };
 
 // Unreachable instruction.  This is a terminator instruction with no
 // operands.
-class InstUnreachable : public Inst {
+class InstUnreachable : public InstHighLevel {
 public:
   static InstUnreachable *create(Cfg *Func) {
     return new (Func->allocateInst<InstUnreachable>()) InstUnreachable(Func);
   }
-  virtual NodeList getTerminatorEdges() const { return NodeList(); }
-  virtual void dump(const Cfg *Func) const;
+  NodeList getTerminatorEdges() const override { return NodeList(); }
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) {
     return Inst->getKind() == Unreachable;
   }
 
 private:
   InstUnreachable(Cfg *Func);
   InstUnreachable(const InstUnreachable &) LLVM_DELETED_FUNCTION;
   InstUnreachable &operator=(const InstUnreachable &) LLVM_DELETED_FUNCTION;
-  virtual ~InstUnreachable() {}
+  ~InstUnreachable() override {}
 };
 
 // FakeDef instruction.  This creates a fake definition of a variable,
 // which is how we represent the case when an instruction produces
 // multiple results.  This doesn't happen with high-level ICE
 // instructions, but might with lowered instructions.  For example,
 // this would be a way to represent condition flags being modified by
 // an instruction.
 //
 // It's generally useful to set the optional source operand to be the
 // dest variable of the instruction that actually produces the FakeDef
 // dest.  Otherwise, the original instruction could be dead-code
 // eliminated if its dest operand is unused, and therefore the FakeDef
 // dest wouldn't be properly initialized.
-class InstFakeDef : public Inst {
+class InstFakeDef : public InstHighLevel {
 public:
   static InstFakeDef *create(Cfg *Func, Variable *Dest, Variable *Src = NULL) {
     return new (Func->allocateInst<InstFakeDef>()) InstFakeDef(Func, Dest, Src);
   }
-  virtual void emit(const Cfg *Func) const;
-  virtual void dump(const Cfg *Func) const;
+  void emit(const Cfg *Func) const override;
+  void emitIAS(const Cfg *Func) const override { emit(Func); }
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return Inst->getKind() == FakeDef; }
 
 private:
   InstFakeDef(Cfg *Func, Variable *Dest, Variable *Src);
   InstFakeDef(const InstFakeDef &) LLVM_DELETED_FUNCTION;
   InstFakeDef &operator=(const InstFakeDef &) LLVM_DELETED_FUNCTION;
-  virtual ~InstFakeDef() {}
+  ~InstFakeDef() override {}
 };
 
 // FakeUse instruction.  This creates a fake use of a variable, to
 // keep the instruction that produces that variable from being
 // dead-code eliminated.  This is useful in a variety of lowering
 // situations.  The FakeUse instruction has no dest, so it can itself
 // never be dead-code eliminated.
-class InstFakeUse : public Inst {
+class InstFakeUse : public InstHighLevel {
 public:
   static InstFakeUse *create(Cfg *Func, Variable *Src) {
     return new (Func->allocateInst<InstFakeUse>()) InstFakeUse(Func, Src);
   }
-  virtual void emit(const Cfg *Func) const;
-  virtual void dump(const Cfg *Func) const;
+  void emit(const Cfg *Func) const override;
+  void emitIAS(const Cfg *Func) const override { emit(Func); }
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return Inst->getKind() == FakeUse; }
 
 private:
   InstFakeUse(Cfg *Func, Variable *Src);
   InstFakeUse(const InstFakeUse &) LLVM_DELETED_FUNCTION;
   InstFakeUse &operator=(const InstFakeUse &) LLVM_DELETED_FUNCTION;
-  virtual ~InstFakeUse() {}
+  ~InstFakeUse() override {}
 };
 
 // FakeKill instruction.  This "kills" a set of variables by adding a
 // trivial live range at this instruction to each variable.  The
 // primary use is to indicate that scratch registers are killed after
 // a call, so that the register allocator won't assign a scratch
 // register to a variable whose live range spans a call.
 //
 // The FakeKill instruction also holds a pointer to the instruction
 // that kills the set of variables, so that if that linked instruction
 // gets dead-code eliminated, the FakeKill instruction will as well.
-class InstFakeKill : public Inst {
+class InstFakeKill : public InstHighLevel {
 public:
   static InstFakeKill *create(Cfg *Func, const VarList &KilledRegs,
                               const Inst *Linked) {
     return new (Func->allocateInst<InstFakeKill>())
         InstFakeKill(Func, KilledRegs, Linked);
   }
   const Inst *getLinked() const { return Linked; }
-  virtual void emit(const Cfg *Func) const;
-  virtual void dump(const Cfg *Func) const;
+  void emit(const Cfg *Func) const override;
+  void emitIAS(const Cfg *Func) const override { emit(Func); }

[jvoung (off chromium), 2014/09/26 16:13:49]

At some point we will have to rely on dump to notice these, and then this
becomes a nop.

[Jim Stichnoth, 2014/09/26 16:27:23]

Now that you mention it, there's not much reason to emit Fake{Def,Use,Kill} at
all, since it's all available in the dump().  I'll remove it (or someone else
can...) at some point.

+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return Inst->getKind() == FakeKill; }
 
 private:
   InstFakeKill(Cfg *Func, const VarList &KilledRegs, const Inst *Linked);
   InstFakeKill(const InstFakeKill &) LLVM_DELETED_FUNCTION;
   InstFakeKill &operator=(const InstFakeKill &) LLVM_DELETED_FUNCTION;
-  virtual ~InstFakeKill() {}
+  ~InstFakeKill() override {}
 
   // This instruction is ignored if Linked->isDeleted() is true.
   const Inst *Linked;
 };
 
 // The Target instruction is the base class for all target-specific
 // instructions.
 class InstTarget : public Inst {
+  InstTarget(const InstTarget &) LLVM_DELETED_FUNCTION;
+  InstTarget &operator=(const InstTarget &) LLVM_DELETED_FUNCTION;
+
 public:
-  virtual uint32_t getEmitInstCount() const { return 1; }
-  virtual void emit(const Cfg *Func) const = 0;
-  virtual void dump(const Cfg *Func) const;
-  virtual void dumpExtras(const Cfg *Func) const;
+  uint32_t getEmitInstCount() const override { return 1; }
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return Inst->getKind() >= Target; }
 
 protected:
   InstTarget(Cfg *Func, InstKind Kind, SizeT MaxSrcs, Variable *Dest)
       : Inst(Func, Kind, MaxSrcs, Dest) {
     assert(Kind >= Target);
   }
-  InstTarget(const InstTarget &) LLVM_DELETED_FUNCTION;
-  InstTarget &operator=(const InstTarget &) LLVM_DELETED_FUNCTION;
-  virtual ~InstTarget() {}
+  void emitIAS(const Cfg *Func) const override { emit(Func); }
+  ~InstTarget() override {}
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEINST_H