Home | History | Annotate | Download | only in IR
      1 //===-- llvm/Instructions.h - Instruction subclass definitions --*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file exposes the class definitions of all of the subclasses of the
     11 // Instruction class.  This is meant to be an easy way to get access to all
     12 // instruction subclasses.
     13 //
     14 //===----------------------------------------------------------------------===//
     15 
     16 #ifndef LLVM_IR_INSTRUCTIONS_H
     17 #define LLVM_IR_INSTRUCTIONS_H
     18 
     19 #include "llvm/ADT/ArrayRef.h"
     20 #include "llvm/ADT/SmallVector.h"
     21 #include "llvm/ADT/iterator_range.h"
     22 #include "llvm/IR/Attributes.h"
     23 #include "llvm/IR/CallingConv.h"
     24 #include "llvm/IR/DerivedTypes.h"
     25 #include "llvm/IR/InstrTypes.h"
     26 #include "llvm/Support/ErrorHandling.h"
     27 #include <iterator>
     28 
     29 namespace llvm {
     30 
     31 class APInt;
     32 class ConstantInt;
     33 class ConstantRange;
     34 class DataLayout;
     35 class LLVMContext;
     36 
     37 enum AtomicOrdering {
     38   NotAtomic = 0,
     39   Unordered = 1,
     40   Monotonic = 2,
     41   // Consume = 3,  // Not specified yet.
     42   Acquire = 4,
     43   Release = 5,
     44   AcquireRelease = 6,
     45   SequentiallyConsistent = 7
     46 };
     47 
     48 enum SynchronizationScope {
     49   SingleThread = 0,
     50   CrossThread = 1
     51 };
     52 
     53 /// Returns true if the ordering is at least as strong as acquire
     54 /// (i.e. acquire, acq_rel or seq_cst)
     55 inline bool isAtLeastAcquire(AtomicOrdering Ord) {
     56    return (Ord == Acquire ||
     57     Ord == AcquireRelease ||
     58     Ord == SequentiallyConsistent);
     59 }
     60 
     61 /// Returns true if the ordering is at least as strong as release
     62 /// (i.e. release, acq_rel or seq_cst)
     63 inline bool isAtLeastRelease(AtomicOrdering Ord) {
     64 return (Ord == Release ||
     65     Ord == AcquireRelease ||
     66     Ord == SequentiallyConsistent);
     67 }
     68 
     69 //===----------------------------------------------------------------------===//
     70 //                                AllocaInst Class
     71 //===----------------------------------------------------------------------===//
     72 
     73 /// AllocaInst - an instruction to allocate memory on the stack
     74 ///
     75 class AllocaInst : public UnaryInstruction {
     76 protected:
     77   AllocaInst *clone_impl() const override;
     78 public:
     79   explicit AllocaInst(Type *Ty, Value *ArraySize = nullptr,
     80                       const Twine &Name = "",
     81                       Instruction *InsertBefore = nullptr);
     82   AllocaInst(Type *Ty, Value *ArraySize,
     83              const Twine &Name, BasicBlock *InsertAtEnd);
     84 
     85   AllocaInst(Type *Ty, const Twine &Name, Instruction *InsertBefore = nullptr);
     86   AllocaInst(Type *Ty, const Twine &Name, BasicBlock *InsertAtEnd);
     87 
     88   AllocaInst(Type *Ty, Value *ArraySize, unsigned Align,
     89              const Twine &Name = "", Instruction *InsertBefore = nullptr);
     90   AllocaInst(Type *Ty, Value *ArraySize, unsigned Align,
     91              const Twine &Name, BasicBlock *InsertAtEnd);
     92 
     93   // Out of line virtual method, so the vtable, etc. has a home.
     94   ~AllocaInst() override;
     95 
     96   /// isArrayAllocation - Return true if there is an allocation size parameter
     97   /// to the allocation instruction that is not 1.
     98   ///
     99   bool isArrayAllocation() const;
    100 
    101   /// getArraySize - Get the number of elements allocated. For a simple
    102   /// allocation of a single element, this will return a constant 1 value.
    103   ///
    104   const Value *getArraySize() const { return getOperand(0); }
    105   Value *getArraySize() { return getOperand(0); }
    106 
    107   /// getType - Overload to return most specific pointer type
    108   ///
    109   PointerType *getType() const {
    110     return cast<PointerType>(Instruction::getType());
    111   }
    112 
    113   /// getAllocatedType - Return the type that is being allocated by the
    114   /// instruction.
    115   ///
    116   Type *getAllocatedType() const;
    117 
    118   /// getAlignment - Return the alignment of the memory that is being allocated
    119   /// by the instruction.
    120   ///
    121   unsigned getAlignment() const {
    122     return (1u << (getSubclassDataFromInstruction() & 31)) >> 1;
    123   }
    124   void setAlignment(unsigned Align);
    125 
    126   /// isStaticAlloca - Return true if this alloca is in the entry block of the
    127   /// function and is a constant size.  If so, the code generator will fold it
    128   /// into the prolog/epilog code, so it is basically free.
    129   bool isStaticAlloca() const;
    130 
    131   /// \brief Return true if this alloca is used as an inalloca argument to a
    132   /// call.  Such allocas are never considered static even if they are in the
    133   /// entry block.
    134   bool isUsedWithInAlloca() const {
    135     return getSubclassDataFromInstruction() & 32;
    136   }
    137 
    138   /// \brief Specify whether this alloca is used to represent the arguments to
    139   /// a call.
    140   void setUsedWithInAlloca(bool V) {
    141     setInstructionSubclassData((getSubclassDataFromInstruction() & ~32) |
    142                                (V ? 32 : 0));
    143   }
    144 
    145   // Methods for support type inquiry through isa, cast, and dyn_cast:
    146   static inline bool classof(const Instruction *I) {
    147     return (I->getOpcode() == Instruction::Alloca);
    148   }
    149   static inline bool classof(const Value *V) {
    150     return isa<Instruction>(V) && classof(cast<Instruction>(V));
    151   }
    152 private:
    153   // Shadow Instruction::setInstructionSubclassData with a private forwarding
    154   // method so that subclasses cannot accidentally use it.
    155   void setInstructionSubclassData(unsigned short D) {
    156     Instruction::setInstructionSubclassData(D);
    157   }
    158 };
    159 
    160 
    161 //===----------------------------------------------------------------------===//
    162 //                                LoadInst Class
    163 //===----------------------------------------------------------------------===//
    164 
    165 /// LoadInst - an instruction for reading from memory.  This uses the
    166 /// SubclassData field in Value to store whether or not the load is volatile.
    167 ///
    168 class LoadInst : public UnaryInstruction {
    169   void AssertOK();
    170 protected:
    171   LoadInst *clone_impl() const override;
    172 public:
    173   LoadInst(Value *Ptr, const Twine &NameStr, Instruction *InsertBefore);
    174   LoadInst(Value *Ptr, const Twine &NameStr, BasicBlock *InsertAtEnd);
    175   LoadInst(Value *Ptr, const Twine &NameStr, bool isVolatile = false,
    176            Instruction *InsertBefore = nullptr);
    177   LoadInst(Value *Ptr, const Twine &NameStr, bool isVolatile,
    178            BasicBlock *InsertAtEnd);
    179   LoadInst(Value *Ptr, const Twine &NameStr, bool isVolatile,
    180            unsigned Align, Instruction *InsertBefore = nullptr);
    181   LoadInst(Value *Ptr, const Twine &NameStr, bool isVolatile,
    182            unsigned Align, BasicBlock *InsertAtEnd);
    183   LoadInst(Value *Ptr, const Twine &NameStr, bool isVolatile, unsigned Align,
    184            AtomicOrdering Order, SynchronizationScope SynchScope = CrossThread,
    185            Instruction *InsertBefore = nullptr)
    186       : LoadInst(cast<PointerType>(Ptr->getType())->getElementType(), Ptr,
    187                  NameStr, isVolatile, Align, Order, SynchScope, InsertBefore) {}
    188   LoadInst(Type *Ty, Value *Ptr, const Twine &NameStr, bool isVolatile,
    189            unsigned Align, AtomicOrdering Order,
    190            SynchronizationScope SynchScope = CrossThread,
    191            Instruction *InsertBefore = nullptr);
    192   LoadInst(Value *Ptr, const Twine &NameStr, bool isVolatile,
    193            unsigned Align, AtomicOrdering Order,
    194            SynchronizationScope SynchScope,
    195            BasicBlock *InsertAtEnd);
    196 
    197   LoadInst(Value *Ptr, const char *NameStr, Instruction *InsertBefore);
    198   LoadInst(Value *Ptr, const char *NameStr, BasicBlock *InsertAtEnd);
    199   explicit LoadInst(Value *Ptr, const char *NameStr = nullptr,
    200                     bool isVolatile = false,
    201                     Instruction *InsertBefore = nullptr);
    202   LoadInst(Value *Ptr, const char *NameStr, bool isVolatile,
    203            BasicBlock *InsertAtEnd);
    204 
    205   /// isVolatile - Return true if this is a load from a volatile memory
    206   /// location.
    207   ///
    208   bool isVolatile() const { return getSubclassDataFromInstruction() & 1; }
    209 
    210   /// setVolatile - Specify whether this is a volatile load or not.
    211   ///
    212   void setVolatile(bool V) {
    213     setInstructionSubclassData((getSubclassDataFromInstruction() & ~1) |
    214                                (V ? 1 : 0));
    215   }
    216 
    217   /// getAlignment - Return the alignment of the access that is being performed
    218   ///
    219   unsigned getAlignment() const {
    220     return (1 << ((getSubclassDataFromInstruction() >> 1) & 31)) >> 1;
    221   }
    222 
    223   void setAlignment(unsigned Align);
    224 
    225   /// Returns the ordering effect of this fence.
    226   AtomicOrdering getOrdering() const {
    227     return AtomicOrdering((getSubclassDataFromInstruction() >> 7) & 7);
    228   }
    229 
    230   /// Set the ordering constraint on this load. May not be Release or
    231   /// AcquireRelease.
    232   void setOrdering(AtomicOrdering Ordering) {
    233     setInstructionSubclassData((getSubclassDataFromInstruction() & ~(7 << 7)) |
    234                                (Ordering << 7));
    235   }
    236 
    237   SynchronizationScope getSynchScope() const {
    238     return SynchronizationScope((getSubclassDataFromInstruction() >> 6) & 1);
    239   }
    240 
    241   /// Specify whether this load is ordered with respect to all
    242   /// concurrently executing threads, or only with respect to signal handlers
    243   /// executing in the same thread.
    244   void setSynchScope(SynchronizationScope xthread) {
    245     setInstructionSubclassData((getSubclassDataFromInstruction() & ~(1 << 6)) |
    246                                (xthread << 6));
    247   }
    248 
    249   void setAtomic(AtomicOrdering Ordering,
    250                  SynchronizationScope SynchScope = CrossThread) {
    251     setOrdering(Ordering);
    252     setSynchScope(SynchScope);
    253   }
    254 
    255   bool isSimple() const { return !isAtomic() && !isVolatile(); }
    256   bool isUnordered() const {
    257     return getOrdering() <= Unordered && !isVolatile();
    258   }
    259 
    260   Value *getPointerOperand() { return getOperand(0); }
    261   const Value *getPointerOperand() const { return getOperand(0); }
    262   static unsigned getPointerOperandIndex() { return 0U; }
    263 
    264   /// \brief Returns the address space of the pointer operand.
    265   unsigned getPointerAddressSpace() const {
    266     return getPointerOperand()->getType()->getPointerAddressSpace();
    267   }
    268 
    269 
    270   // Methods for support type inquiry through isa, cast, and dyn_cast:
    271   static inline bool classof(const Instruction *I) {
    272     return I->getOpcode() == Instruction::Load;
    273   }
    274   static inline bool classof(const Value *V) {
    275     return isa<Instruction>(V) && classof(cast<Instruction>(V));
    276   }
    277 private:
    278   // Shadow Instruction::setInstructionSubclassData with a private forwarding
    279   // method so that subclasses cannot accidentally use it.
    280   void setInstructionSubclassData(unsigned short D) {
    281     Instruction::setInstructionSubclassData(D);
    282   }
    283 };
    284 
    285 
    286 //===----------------------------------------------------------------------===//
    287 //                                StoreInst Class
    288 //===----------------------------------------------------------------------===//
    289 
    290 /// StoreInst - an instruction for storing to memory
    291 ///
    292 class StoreInst : public Instruction {
    293   void *operator new(size_t, unsigned) = delete;
    294   void AssertOK();
    295 protected:
    296   StoreInst *clone_impl() const override;
    297 public:
    298   // allocate space for exactly two operands
    299   void *operator new(size_t s) {
    300     return User::operator new(s, 2);
    301   }
    302   StoreInst(Value *Val, Value *Ptr, Instruction *InsertBefore);
    303   StoreInst(Value *Val, Value *Ptr, BasicBlock *InsertAtEnd);
    304   StoreInst(Value *Val, Value *Ptr, bool isVolatile = false,
    305             Instruction *InsertBefore = nullptr);
    306   StoreInst(Value *Val, Value *Ptr, bool isVolatile, BasicBlock *InsertAtEnd);
    307   StoreInst(Value *Val, Value *Ptr, bool isVolatile,
    308             unsigned Align, Instruction *InsertBefore = nullptr);
    309   StoreInst(Value *Val, Value *Ptr, bool isVolatile,
    310             unsigned Align, BasicBlock *InsertAtEnd);
    311   StoreInst(Value *Val, Value *Ptr, bool isVolatile,
    312             unsigned Align, AtomicOrdering Order,
    313             SynchronizationScope SynchScope = CrossThread,
    314             Instruction *InsertBefore = nullptr);
    315   StoreInst(Value *Val, Value *Ptr, bool isVolatile,
    316             unsigned Align, AtomicOrdering Order,
    317             SynchronizationScope SynchScope,
    318             BasicBlock *InsertAtEnd);
    319 
    320 
    321   /// isVolatile - Return true if this is a store to a volatile memory
    322   /// location.
    323   ///
    324   bool isVolatile() const { return getSubclassDataFromInstruction() & 1; }
    325 
    326   /// setVolatile - Specify whether this is a volatile store or not.
    327   ///
    328   void setVolatile(bool V) {
    329     setInstructionSubclassData((getSubclassDataFromInstruction() & ~1) |
    330                                (V ? 1 : 0));
    331   }
    332 
    333   /// Transparently provide more efficient getOperand methods.
    334   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
    335 
    336   /// getAlignment - Return the alignment of the access that is being performed
    337   ///
    338   unsigned getAlignment() const {
    339     return (1 << ((getSubclassDataFromInstruction() >> 1) & 31)) >> 1;
    340   }
    341 
    342   void setAlignment(unsigned Align);
    343 
    344   /// Returns the ordering effect of this store.
    345   AtomicOrdering getOrdering() const {
    346     return AtomicOrdering((getSubclassDataFromInstruction() >> 7) & 7);
    347   }
    348 
    349   /// Set the ordering constraint on this store.  May not be Acquire or
    350   /// AcquireRelease.
    351   void setOrdering(AtomicOrdering Ordering) {
    352     setInstructionSubclassData((getSubclassDataFromInstruction() & ~(7 << 7)) |
    353                                (Ordering << 7));
    354   }
    355 
    356   SynchronizationScope getSynchScope() const {
    357     return SynchronizationScope((getSubclassDataFromInstruction() >> 6) & 1);
    358   }
    359 
    360   /// Specify whether this store instruction is ordered with respect to all
    361   /// concurrently executing threads, or only with respect to signal handlers
    362   /// executing in the same thread.
    363   void setSynchScope(SynchronizationScope xthread) {
    364     setInstructionSubclassData((getSubclassDataFromInstruction() & ~(1 << 6)) |
    365                                (xthread << 6));
    366   }
    367 
    368   void setAtomic(AtomicOrdering Ordering,
    369                  SynchronizationScope SynchScope = CrossThread) {
    370     setOrdering(Ordering);
    371     setSynchScope(SynchScope);
    372   }
    373 
    374   bool isSimple() const { return !isAtomic() && !isVolatile(); }
    375   bool isUnordered() const {
    376     return getOrdering() <= Unordered && !isVolatile();
    377   }
    378 
    379   Value *getValueOperand() { return getOperand(0); }
    380   const Value *getValueOperand() const { return getOperand(0); }
    381 
    382   Value *getPointerOperand() { return getOperand(1); }
    383   const Value *getPointerOperand() const { return getOperand(1); }
    384   static unsigned getPointerOperandIndex() { return 1U; }
    385 
    386   /// \brief Returns the address space of the pointer operand.
    387   unsigned getPointerAddressSpace() const {
    388     return getPointerOperand()->getType()->getPointerAddressSpace();
    389   }
    390 
    391   // Methods for support type inquiry through isa, cast, and dyn_cast:
    392   static inline bool classof(const Instruction *I) {
    393     return I->getOpcode() == Instruction::Store;
    394   }
    395   static inline bool classof(const Value *V) {
    396     return isa<Instruction>(V) && classof(cast<Instruction>(V));
    397   }
    398 private:
    399   // Shadow Instruction::setInstructionSubclassData with a private forwarding
    400   // method so that subclasses cannot accidentally use it.
    401   void setInstructionSubclassData(unsigned short D) {
    402     Instruction::setInstructionSubclassData(D);
    403   }
    404 };
    405 
    406 template <>
    407 struct OperandTraits<StoreInst> : public FixedNumOperandTraits<StoreInst, 2> {
    408 };
    409 
    410 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(StoreInst, Value)
    411 
    412 //===----------------------------------------------------------------------===//
    413 //                                FenceInst Class
    414 //===----------------------------------------------------------------------===//
    415 
    416 /// FenceInst - an instruction for ordering other memory operations
    417 ///
    418 class FenceInst : public Instruction {
    419   void *operator new(size_t, unsigned) = delete;
    420   void Init(AtomicOrdering Ordering, SynchronizationScope SynchScope);
    421 protected:
    422   FenceInst *clone_impl() const override;
    423 public:
    424   // allocate space for exactly zero operands
    425   void *operator new(size_t s) {
    426     return User::operator new(s, 0);
    427   }
    428 
    429   // Ordering may only be Acquire, Release, AcquireRelease, or
    430   // SequentiallyConsistent.
    431   FenceInst(LLVMContext &C, AtomicOrdering Ordering,
    432             SynchronizationScope SynchScope = CrossThread,
    433             Instruction *InsertBefore = nullptr);
    434   FenceInst(LLVMContext &C, AtomicOrdering Ordering,
    435             SynchronizationScope SynchScope,
    436             BasicBlock *InsertAtEnd);
    437 
    438   /// Returns the ordering effect of this fence.
    439   AtomicOrdering getOrdering() const {
    440     return AtomicOrdering(getSubclassDataFromInstruction() >> 1);
    441   }
    442 
    443   /// Set the ordering constraint on this fence.  May only be Acquire, Release,
    444   /// AcquireRelease, or SequentiallyConsistent.
    445   void setOrdering(AtomicOrdering Ordering) {
    446     setInstructionSubclassData((getSubclassDataFromInstruction() & 1) |
    447                                (Ordering << 1));
    448   }
    449 
    450   SynchronizationScope getSynchScope() const {
    451     return SynchronizationScope(getSubclassDataFromInstruction() & 1);
    452   }
    453 
    454   /// Specify whether this fence orders other operations with respect to all
    455   /// concurrently executing threads, or only with respect to signal handlers
    456   /// executing in the same thread.
    457   void setSynchScope(SynchronizationScope xthread) {
    458     setInstructionSubclassData((getSubclassDataFromInstruction() & ~1) |
    459                                xthread);
    460   }
    461 
    462   // Methods for support type inquiry through isa, cast, and dyn_cast:
    463   static inline bool classof(const Instruction *I) {
    464     return I->getOpcode() == Instruction::Fence;
    465   }
    466   static inline bool classof(const Value *V) {
    467     return isa<Instruction>(V) && classof(cast<Instruction>(V));
    468   }
    469 private:
    470   // Shadow Instruction::setInstructionSubclassData with a private forwarding
    471   // method so that subclasses cannot accidentally use it.
    472   void setInstructionSubclassData(unsigned short D) {
    473     Instruction::setInstructionSubclassData(D);
    474   }
    475 };
    476 
    477 //===----------------------------------------------------------------------===//
    478 //                                AtomicCmpXchgInst Class
    479 //===----------------------------------------------------------------------===//
    480 
    481 /// AtomicCmpXchgInst - an instruction that atomically checks whether a
    482 /// specified value is in a memory location, and, if it is, stores a new value
    483 /// there.  Returns the value that was loaded.
    484 ///
    485 class AtomicCmpXchgInst : public Instruction {
    486   void *operator new(size_t, unsigned) = delete;
    487   void Init(Value *Ptr, Value *Cmp, Value *NewVal,
    488             AtomicOrdering SuccessOrdering, AtomicOrdering FailureOrdering,
    489             SynchronizationScope SynchScope);
    490 protected:
    491   AtomicCmpXchgInst *clone_impl() const override;
    492 public:
    493   // allocate space for exactly three operands
    494   void *operator new(size_t s) {
    495     return User::operator new(s, 3);
    496   }
    497   AtomicCmpXchgInst(Value *Ptr, Value *Cmp, Value *NewVal,
    498                     AtomicOrdering SuccessOrdering,
    499                     AtomicOrdering FailureOrdering,
    500                     SynchronizationScope SynchScope,
    501                     Instruction *InsertBefore = nullptr);
    502   AtomicCmpXchgInst(Value *Ptr, Value *Cmp, Value *NewVal,
    503                     AtomicOrdering SuccessOrdering,
    504                     AtomicOrdering FailureOrdering,
    505                     SynchronizationScope SynchScope,
    506                     BasicBlock *InsertAtEnd);
    507 
    508   /// isVolatile - Return true if this is a cmpxchg from a volatile memory
    509   /// location.
    510   ///
    511   bool isVolatile() const {
    512     return getSubclassDataFromInstruction() & 1;
    513   }
    514 
    515   /// setVolatile - Specify whether this is a volatile cmpxchg.
    516   ///
    517   void setVolatile(bool V) {
    518      setInstructionSubclassData((getSubclassDataFromInstruction() & ~1) |
    519                                 (unsigned)V);
    520   }
    521 
    522   /// Return true if this cmpxchg may spuriously fail.
    523   bool isWeak() const {
    524     return getSubclassDataFromInstruction() & 0x100;
    525   }
    526 
    527   void setWeak(bool IsWeak) {
    528     setInstructionSubclassData((getSubclassDataFromInstruction() & ~0x100) |
    529                                (IsWeak << 8));
    530   }
    531 
    532   /// Transparently provide more efficient getOperand methods.
    533   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
    534 
    535   /// Set the ordering constraint on this cmpxchg.
    536   void setSuccessOrdering(AtomicOrdering Ordering) {
    537     assert(Ordering != NotAtomic &&
    538            "CmpXchg instructions can only be atomic.");
    539     setInstructionSubclassData((getSubclassDataFromInstruction() & ~0x1c) |
    540                                (Ordering << 2));
    541   }
    542 
    543   void setFailureOrdering(AtomicOrdering Ordering) {
    544     assert(Ordering != NotAtomic &&
    545            "CmpXchg instructions can only be atomic.");
    546     setInstructionSubclassData((getSubclassDataFromInstruction() & ~0xe0) |
    547                                (Ordering << 5));
    548   }
    549 
    550   /// Specify whether this cmpxchg is atomic and orders other operations with
    551   /// respect to all concurrently executing threads, or only with respect to
    552   /// signal handlers executing in the same thread.
    553   void setSynchScope(SynchronizationScope SynchScope) {
    554     setInstructionSubclassData((getSubclassDataFromInstruction() & ~2) |
    555                                (SynchScope << 1));
    556   }
    557 
    558   /// Returns the ordering constraint on this cmpxchg.
    559   AtomicOrdering getSuccessOrdering() const {
    560     return AtomicOrdering((getSubclassDataFromInstruction() >> 2) & 7);
    561   }
    562 
    563   /// Returns the ordering constraint on this cmpxchg.
    564   AtomicOrdering getFailureOrdering() const {
    565     return AtomicOrdering((getSubclassDataFromInstruction() >> 5) & 7);
    566   }
    567 
    568   /// Returns whether this cmpxchg is atomic between threads or only within a
    569   /// single thread.
    570   SynchronizationScope getSynchScope() const {
    571     return SynchronizationScope((getSubclassDataFromInstruction() & 2) >> 1);
    572   }
    573 
    574   Value *getPointerOperand() { return getOperand(0); }
    575   const Value *getPointerOperand() const { return getOperand(0); }
    576   static unsigned getPointerOperandIndex() { return 0U; }
    577 
    578   Value *getCompareOperand() { return getOperand(1); }
    579   const Value *getCompareOperand() const { return getOperand(1); }
    580 
    581   Value *getNewValOperand() { return getOperand(2); }
    582   const Value *getNewValOperand() const { return getOperand(2); }
    583 
    584   /// \brief Returns the address space of the pointer operand.
    585   unsigned getPointerAddressSpace() const {
    586     return getPointerOperand()->getType()->getPointerAddressSpace();
    587   }
    588 
    589   /// \brief Returns the strongest permitted ordering on failure, given the
    590   /// desired ordering on success.
    591   ///
    592   /// If the comparison in a cmpxchg operation fails, there is no atomic store
    593   /// so release semantics cannot be provided. So this function drops explicit
    594   /// Release requests from the AtomicOrdering. A SequentiallyConsistent
    595   /// operation would remain SequentiallyConsistent.
    596   static AtomicOrdering
    597   getStrongestFailureOrdering(AtomicOrdering SuccessOrdering) {
    598     switch (SuccessOrdering) {
    599     default: llvm_unreachable("invalid cmpxchg success ordering");
    600     case Release:
    601     case Monotonic:
    602       return Monotonic;
    603     case AcquireRelease:
    604     case Acquire:
    605       return Acquire;
    606     case SequentiallyConsistent:
    607       return SequentiallyConsistent;
    608     }
    609   }
    610 
    611   // Methods for support type inquiry through isa, cast, and dyn_cast:
    612   static inline bool classof(const Instruction *I) {
    613     return I->getOpcode() == Instruction::AtomicCmpXchg;
    614   }
    615   static inline bool classof(const Value *V) {
    616     return isa<Instruction>(V) && classof(cast<Instruction>(V));
    617   }
    618 private:
    619   // Shadow Instruction::setInstructionSubclassData with a private forwarding
    620   // method so that subclasses cannot accidentally use it.
    621   void setInstructionSubclassData(unsigned short D) {
    622     Instruction::setInstructionSubclassData(D);
    623   }
    624 };
    625 
    626 template <>
    627 struct OperandTraits<AtomicCmpXchgInst> :
    628     public FixedNumOperandTraits<AtomicCmpXchgInst, 3> {
    629 };
    630 
    631 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(AtomicCmpXchgInst, Value)
    632 
    633 //===----------------------------------------------------------------------===//
    634 //                                AtomicRMWInst Class
    635 //===----------------------------------------------------------------------===//
    636 
    637 /// AtomicRMWInst - an instruction that atomically reads a memory location,
    638 /// combines it with another value, and then stores the result back.  Returns
    639 /// the old value.
    640 ///
    641 class AtomicRMWInst : public Instruction {
    642   void *operator new(size_t, unsigned) = delete;
    643 protected:
    644   AtomicRMWInst *clone_impl() const override;
    645 public:
    646   /// This enumeration lists the possible modifications atomicrmw can make.  In
    647   /// the descriptions, 'p' is the pointer to the instruction's memory location,
    648   /// 'old' is the initial value of *p, and 'v' is the other value passed to the
    649   /// instruction.  These instructions always return 'old'.
    650   enum BinOp {
    651     /// *p = v
    652     Xchg,
    653     /// *p = old + v
    654     Add,
    655     /// *p = old - v
    656     Sub,
    657     /// *p = old & v
    658     And,
    659     /// *p = ~(old & v)
    660     Nand,
    661     /// *p = old | v
    662     Or,
    663     /// *p = old ^ v
    664     Xor,
    665     /// *p = old >signed v ? old : v
    666     Max,
    667     /// *p = old <signed v ? old : v
    668     Min,
    669     /// *p = old >unsigned v ? old : v
    670     UMax,
    671     /// *p = old <unsigned v ? old : v
    672     UMin,
    673 
    674     FIRST_BINOP = Xchg,
    675     LAST_BINOP = UMin,
    676     BAD_BINOP
    677   };
    678 
    679   // allocate space for exactly two operands
    680   void *operator new(size_t s) {
    681     return User::operator new(s, 2);
    682   }
    683   AtomicRMWInst(BinOp Operation, Value *Ptr, Value *Val,
    684                 AtomicOrdering Ordering, SynchronizationScope SynchScope,
    685                 Instruction *InsertBefore = nullptr);
    686   AtomicRMWInst(BinOp Operation, Value *Ptr, Value *Val,
    687                 AtomicOrdering Ordering, SynchronizationScope SynchScope,
    688                 BasicBlock *InsertAtEnd);
    689 
    690   BinOp getOperation() const {
    691     return static_cast<BinOp>(getSubclassDataFromInstruction() >> 5);
    692   }
    693 
    694   void setOperation(BinOp Operation) {
    695     unsigned short SubclassData = getSubclassDataFromInstruction();
    696     setInstructionSubclassData((SubclassData & 31) |
    697                                (Operation << 5));
    698   }
    699 
    700   /// isVolatile - Return true if this is a RMW on a volatile memory location.
    701   ///
    702   bool isVolatile() const {
    703     return getSubclassDataFromInstruction() & 1;
    704   }
    705 
    706   /// setVolatile - Specify whether this is a volatile RMW or not.
    707   ///
    708   void setVolatile(bool V) {
    709      setInstructionSubclassData((getSubclassDataFromInstruction() & ~1) |
    710                                 (unsigned)V);
    711   }
    712 
    713   /// Transparently provide more efficient getOperand methods.
    714   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
    715 
    716   /// Set the ordering constraint on this RMW.
    717   void setOrdering(AtomicOrdering Ordering) {
    718     assert(Ordering != NotAtomic &&
    719            "atomicrmw instructions can only be atomic.");
    720     setInstructionSubclassData((getSubclassDataFromInstruction() & ~(7 << 2)) |
    721                                (Ordering << 2));
    722   }
    723 
    724   /// Specify whether this RMW orders other operations with respect to all
    725   /// concurrently executing threads, or only with respect to signal handlers
    726   /// executing in the same thread.
    727   void setSynchScope(SynchronizationScope SynchScope) {
    728     setInstructionSubclassData((getSubclassDataFromInstruction() & ~2) |
    729                                (SynchScope << 1));
    730   }
    731 
    732   /// Returns the ordering constraint on this RMW.
    733   AtomicOrdering getOrdering() const {
    734     return AtomicOrdering((getSubclassDataFromInstruction() >> 2) & 7);
    735   }
    736 
    737   /// Returns whether this RMW is atomic between threads or only within a
    738   /// single thread.
    739   SynchronizationScope getSynchScope() const {
    740     return SynchronizationScope((getSubclassDataFromInstruction() & 2) >> 1);
    741   }
    742 
    743   Value *getPointerOperand() { return getOperand(0); }
    744   const Value *getPointerOperand() const { return getOperand(0); }
    745   static unsigned getPointerOperandIndex() { return 0U; }
    746 
    747   Value *getValOperand() { return getOperand(1); }
    748   const Value *getValOperand() const { return getOperand(1); }
    749 
    750   /// \brief Returns the address space of the pointer operand.
    751   unsigned getPointerAddressSpace() const {
    752     return getPointerOperand()->getType()->getPointerAddressSpace();
    753   }
    754 
    755   // Methods for support type inquiry through isa, cast, and dyn_cast:
    756   static inline bool classof(const Instruction *I) {
    757     return I->getOpcode() == Instruction::AtomicRMW;
    758   }
    759   static inline bool classof(const Value *V) {
    760     return isa<Instruction>(V) && classof(cast<Instruction>(V));
    761   }
    762 private:
    763   void Init(BinOp Operation, Value *Ptr, Value *Val,
    764             AtomicOrdering Ordering, SynchronizationScope SynchScope);
    765   // Shadow Instruction::setInstructionSubclassData with a private forwarding
    766   // method so that subclasses cannot accidentally use it.
    767   void setInstructionSubclassData(unsigned short D) {
    768     Instruction::setInstructionSubclassData(D);
    769   }
    770 };
    771 
    772 template <>
    773 struct OperandTraits<AtomicRMWInst>
    774     : public FixedNumOperandTraits<AtomicRMWInst,2> {
    775 };
    776 
    777 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(AtomicRMWInst, Value)
    778 
    779 //===----------------------------------------------------------------------===//
    780 //                             GetElementPtrInst Class
    781 //===----------------------------------------------------------------------===//
    782 
    783 // checkGEPType - Simple wrapper function to give a better assertion failure
    784 // message on bad indexes for a gep instruction.
    785 //
    786 inline Type *checkGEPType(Type *Ty) {
    787   assert(Ty && "Invalid GetElementPtrInst indices for type!");
    788   return Ty;
    789 }
    790 
    791 /// GetElementPtrInst - an instruction for type-safe pointer arithmetic to
    792 /// access elements of arrays and structs
    793 ///
    794 class GetElementPtrInst : public Instruction {
    795   GetElementPtrInst(const GetElementPtrInst &GEPI);
    796   void init(Value *Ptr, ArrayRef<Value *> IdxList, const Twine &NameStr);
    797 
    798   /// Constructors - Create a getelementptr instruction with a base pointer an
    799   /// list of indices. The first ctor can optionally insert before an existing
    800   /// instruction, the second appends the new instruction to the specified
    801   /// BasicBlock.
    802   inline GetElementPtrInst(Type *PointeeType, Value *Ptr,
    803                            ArrayRef<Value *> IdxList, unsigned Values,
    804                            const Twine &NameStr, Instruction *InsertBefore);
    805   inline GetElementPtrInst(Type *PointeeType, Value *Ptr,
    806                            ArrayRef<Value *> IdxList, unsigned Values,
    807                            const Twine &NameStr, BasicBlock *InsertAtEnd);
    808 
    809 protected:
    810   GetElementPtrInst *clone_impl() const override;
    811 public:
    812   static GetElementPtrInst *Create(Type *PointeeType, Value *Ptr,
    813                                    ArrayRef<Value *> IdxList,
    814                                    const Twine &NameStr = "",
    815                                    Instruction *InsertBefore = nullptr) {
    816     unsigned Values = 1 + unsigned(IdxList.size());
    817     return new (Values) GetElementPtrInst(PointeeType, Ptr, IdxList, Values,
    818                                           NameStr, InsertBefore);
    819   }
    820   static GetElementPtrInst *Create(Type *PointeeType, Value *Ptr,
    821                                    ArrayRef<Value *> IdxList,
    822                                    const Twine &NameStr,
    823                                    BasicBlock *InsertAtEnd) {
    824     unsigned Values = 1 + unsigned(IdxList.size());
    825     return new (Values) GetElementPtrInst(PointeeType, Ptr, IdxList, Values,
    826                                           NameStr, InsertAtEnd);
    827   }
    828 
    829   /// Create an "inbounds" getelementptr. See the documentation for the
    830   /// "inbounds" flag in LangRef.html for details.
    831   static GetElementPtrInst *CreateInBounds(Value *Ptr,
    832                                            ArrayRef<Value *> IdxList,
    833                                            const Twine &NameStr = "",
    834                                            Instruction *InsertBefore = nullptr){
    835     return CreateInBounds(nullptr, Ptr, IdxList, NameStr, InsertBefore);
    836   }
    837   static GetElementPtrInst *
    838   CreateInBounds(Type *PointeeType, Value *Ptr, ArrayRef<Value *> IdxList,
    839                  const Twine &NameStr = "",
    840                  Instruction *InsertBefore = nullptr) {
    841     GetElementPtrInst *GEP =
    842         Create(PointeeType, Ptr, IdxList, NameStr, InsertBefore);
    843     GEP->setIsInBounds(true);
    844     return GEP;
    845   }
    846   static GetElementPtrInst *CreateInBounds(Value *Ptr,
    847                                            ArrayRef<Value *> IdxList,
    848                                            const Twine &NameStr,
    849                                            BasicBlock *InsertAtEnd) {
    850     return CreateInBounds(nullptr, Ptr, IdxList, NameStr, InsertAtEnd);
    851   }
    852   static GetElementPtrInst *CreateInBounds(Type *PointeeType, Value *Ptr,
    853                                            ArrayRef<Value *> IdxList,
    854                                            const Twine &NameStr,
    855                                            BasicBlock *InsertAtEnd) {
    856     GetElementPtrInst *GEP =
    857         Create(PointeeType, Ptr, IdxList, NameStr, InsertAtEnd);
    858     GEP->setIsInBounds(true);
    859     return GEP;
    860   }
    861 
    862   /// Transparently provide more efficient getOperand methods.
    863   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
    864 
    865   // getType - Overload to return most specific sequential type.
    866   SequentialType *getType() const {
    867     return cast<SequentialType>(Instruction::getType());
    868   }
    869 
    870   Type *getSourceElementType() const {
    871     return cast<SequentialType>(getPointerOperandType()->getScalarType())
    872         ->getElementType();
    873   }
    874 
    875   Type *getResultElementType() const { return getType()->getElementType(); }
    876 
    877   /// \brief Returns the address space of this instruction's pointer type.
    878   unsigned getAddressSpace() const {
    879     // Note that this is always the same as the pointer operand's address space
    880     // and that is cheaper to compute, so cheat here.
    881     return getPointerAddressSpace();
    882   }
    883 
    884   /// getIndexedType - Returns the type of the element that would be loaded with
    885   /// a load instruction with the specified parameters.
    886   ///
    887   /// Null is returned if the indices are invalid for the specified
    888   /// pointer type.
    889   ///
    890   static Type *getIndexedType(Type *Ty, ArrayRef<Value *> IdxList);
    891   static Type *getIndexedType(Type *Ty, ArrayRef<Constant *> IdxList);
    892   static Type *getIndexedType(Type *Ty, ArrayRef<uint64_t> IdxList);
    893 
    894   inline op_iterator       idx_begin()       { return op_begin()+1; }
    895   inline const_op_iterator idx_begin() const { return op_begin()+1; }
    896   inline op_iterator       idx_end()         { return op_end(); }
    897   inline const_op_iterator idx_end()   const { return op_end(); }
    898 
    899   Value *getPointerOperand() {
    900     return getOperand(0);
    901   }
    902   const Value *getPointerOperand() const {
    903     return getOperand(0);
    904   }
    905   static unsigned getPointerOperandIndex() {
    906     return 0U;    // get index for modifying correct operand.
    907   }
    908 
    909   /// getPointerOperandType - Method to return the pointer operand as a
    910   /// PointerType.
    911   Type *getPointerOperandType() const {
    912     return getPointerOperand()->getType();
    913   }
    914 
    915   /// \brief Returns the address space of the pointer operand.
    916   unsigned getPointerAddressSpace() const {
    917     return getPointerOperandType()->getPointerAddressSpace();
    918   }
    919 
    920   /// GetGEPReturnType - Returns the pointer type returned by the GEP
    921   /// instruction, which may be a vector of pointers.
    922   static Type *getGEPReturnType(Value *Ptr, ArrayRef<Value *> IdxList) {
    923     Type *PtrTy =
    924         PointerType::get(checkGEPType(getIndexedType(
    925                              cast<PointerType>(Ptr->getType()->getScalarType())
    926                                  ->getElementType(),
    927                              IdxList)),
    928                          Ptr->getType()->getPointerAddressSpace());
    929     // Vector GEP
    930     if (Ptr->getType()->isVectorTy()) {
    931       unsigned NumElem = cast<VectorType>(Ptr->getType())->getNumElements();
    932       return VectorType::get(PtrTy, NumElem);
    933     }
    934 
    935     // Scalar GEP
    936     return PtrTy;
    937   }
    938 
    939   unsigned getNumIndices() const {  // Note: always non-negative
    940     return getNumOperands() - 1;
    941   }
    942 
    943   bool hasIndices() const {
    944     return getNumOperands() > 1;
    945   }
    946 
    947   /// hasAllZeroIndices - Return true if all of the indices of this GEP are
    948   /// zeros.  If so, the result pointer and the first operand have the same
    949   /// value, just potentially different types.
    950   bool hasAllZeroIndices() const;
    951 
    952   /// hasAllConstantIndices - Return true if all of the indices of this GEP are
    953   /// constant integers.  If so, the result pointer and the first operand have
    954   /// a constant offset between them.
    955   bool hasAllConstantIndices() const;
    956 
    957   /// setIsInBounds - Set or clear the inbounds flag on this GEP instruction.
    958   /// See LangRef.html for the meaning of inbounds on a getelementptr.
    959   void setIsInBounds(bool b = true);
    960 
    961   /// isInBounds - Determine whether the GEP has the inbounds flag.
    962   bool isInBounds() const;
    963 
    964   /// \brief Accumulate the constant address offset of this GEP if possible.
    965   ///
    966   /// This routine accepts an APInt into which it will accumulate the constant
    967   /// offset of this GEP if the GEP is in fact constant. If the GEP is not
    968   /// all-constant, it returns false and the value of the offset APInt is
    969   /// undefined (it is *not* preserved!). The APInt passed into this routine
    970   /// must be at least as wide as the IntPtr type for the address space of
    971   /// the base GEP pointer.
    972   bool accumulateConstantOffset(const DataLayout &DL, APInt &Offset) const;
    973 
    974   // Methods for support type inquiry through isa, cast, and dyn_cast:
    975   static inline bool classof(const Instruction *I) {
    976     return (I->getOpcode() == Instruction::GetElementPtr);
    977   }
    978   static inline bool classof(const Value *V) {
    979     return isa<Instruction>(V) && classof(cast<Instruction>(V));
    980   }
    981 };
    982 
    983 template <>
    984 struct OperandTraits<GetElementPtrInst> :
    985   public VariadicOperandTraits<GetElementPtrInst, 1> {
    986 };
    987 
    988 GetElementPtrInst::GetElementPtrInst(Type *PointeeType, Value *Ptr,
    989                                      ArrayRef<Value *> IdxList, unsigned Values,
    990                                      const Twine &NameStr,
    991                                      Instruction *InsertBefore)
    992     : Instruction(getGEPReturnType(Ptr, IdxList), GetElementPtr,
    993                   OperandTraits<GetElementPtrInst>::op_end(this) - Values,
    994                   Values, InsertBefore) {
    995   init(Ptr, IdxList, NameStr);
    996   assert(!PointeeType || PointeeType == getSourceElementType());
    997 }
    998 GetElementPtrInst::GetElementPtrInst(Type *PointeeType, Value *Ptr,
    999                                      ArrayRef<Value *> IdxList, unsigned Values,
   1000                                      const Twine &NameStr,
   1001                                      BasicBlock *InsertAtEnd)
   1002     : Instruction(getGEPReturnType(Ptr, IdxList), GetElementPtr,
   1003                   OperandTraits<GetElementPtrInst>::op_end(this) - Values,
   1004                   Values, InsertAtEnd) {
   1005   init(Ptr, IdxList, NameStr);
   1006   assert(!PointeeType || PointeeType == getSourceElementType());
   1007 }
   1008 
   1009 
   1010 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(GetElementPtrInst, Value)
   1011 
   1012 
   1013 //===----------------------------------------------------------------------===//
   1014 //                               ICmpInst Class
   1015 //===----------------------------------------------------------------------===//
   1016 
   1017 /// This instruction compares its operands according to the predicate given
   1018 /// to the constructor. It only operates on integers or pointers. The operands
   1019 /// must be identical types.
   1020 /// \brief Represent an integer comparison operator.
   1021 class ICmpInst: public CmpInst {
   1022   void AssertOK() {
   1023     assert(getPredicate() >= CmpInst::FIRST_ICMP_PREDICATE &&
   1024            getPredicate() <= CmpInst::LAST_ICMP_PREDICATE &&
   1025            "Invalid ICmp predicate value");
   1026     assert(getOperand(0)->getType() == getOperand(1)->getType() &&
   1027           "Both operands to ICmp instruction are not of the same type!");
   1028     // Check that the operands are the right type
   1029     assert((getOperand(0)->getType()->isIntOrIntVectorTy() ||
   1030             getOperand(0)->getType()->isPtrOrPtrVectorTy()) &&
   1031            "Invalid operand types for ICmp instruction");
   1032   }
   1033 
   1034 protected:
   1035   /// \brief Clone an identical ICmpInst
   1036   ICmpInst *clone_impl() const override;
   1037 public:
   1038   /// \brief Constructor with insert-before-instruction semantics.
   1039   ICmpInst(
   1040     Instruction *InsertBefore,  ///< Where to insert
   1041     Predicate pred,  ///< The predicate to use for the comparison
   1042     Value *LHS,      ///< The left-hand-side of the expression
   1043     Value *RHS,      ///< The right-hand-side of the expression
   1044     const Twine &NameStr = ""  ///< Name of the instruction
   1045   ) : CmpInst(makeCmpResultType(LHS->getType()),
   1046               Instruction::ICmp, pred, LHS, RHS, NameStr,
   1047               InsertBefore) {
   1048 #ifndef NDEBUG
   1049   AssertOK();
   1050 #endif
   1051   }
   1052 
   1053   /// \brief Constructor with insert-at-end semantics.
   1054   ICmpInst(
   1055     BasicBlock &InsertAtEnd, ///< Block to insert into.
   1056     Predicate pred,  ///< The predicate to use for the comparison
   1057     Value *LHS,      ///< The left-hand-side of the expression
   1058     Value *RHS,      ///< The right-hand-side of the expression
   1059     const Twine &NameStr = ""  ///< Name of the instruction
   1060   ) : CmpInst(makeCmpResultType(LHS->getType()),
   1061               Instruction::ICmp, pred, LHS, RHS, NameStr,
   1062               &InsertAtEnd) {
   1063 #ifndef NDEBUG
   1064   AssertOK();
   1065 #endif
   1066   }
   1067 
   1068   /// \brief Constructor with no-insertion semantics
   1069   ICmpInst(
   1070     Predicate pred, ///< The predicate to use for the comparison
   1071     Value *LHS,     ///< The left-hand-side of the expression
   1072     Value *RHS,     ///< The right-hand-side of the expression
   1073     const Twine &NameStr = "" ///< Name of the instruction
   1074   ) : CmpInst(makeCmpResultType(LHS->getType()),
   1075               Instruction::ICmp, pred, LHS, RHS, NameStr) {
   1076 #ifndef NDEBUG
   1077   AssertOK();
   1078 #endif
   1079   }
   1080 
   1081   /// For example, EQ->EQ, SLE->SLE, UGT->SGT, etc.
   1082   /// @returns the predicate that would be the result if the operand were
   1083   /// regarded as signed.
   1084   /// \brief Return the signed version of the predicate
   1085   Predicate getSignedPredicate() const {
   1086     return getSignedPredicate(getPredicate());
   1087   }
   1088 
   1089   /// This is a static version that you can use without an instruction.
   1090   /// \brief Return the signed version of the predicate.
   1091   static Predicate getSignedPredicate(Predicate pred);
   1092 
   1093   /// For example, EQ->EQ, SLE->ULE, UGT->UGT, etc.
   1094   /// @returns the predicate that would be the result if the operand were
   1095   /// regarded as unsigned.
   1096   /// \brief Return the unsigned version of the predicate
   1097   Predicate getUnsignedPredicate() const {
   1098     return getUnsignedPredicate(getPredicate());
   1099   }
   1100 
   1101   /// This is a static version that you can use without an instruction.
   1102   /// \brief Return the unsigned version of the predicate.
   1103   static Predicate getUnsignedPredicate(Predicate pred);
   1104 
   1105   /// isEquality - Return true if this predicate is either EQ or NE.  This also
   1106   /// tests for commutativity.
   1107   static bool isEquality(Predicate P) {
   1108     return P == ICMP_EQ || P == ICMP_NE;
   1109   }
   1110 
   1111   /// isEquality - Return true if this predicate is either EQ or NE.  This also
   1112   /// tests for commutativity.
   1113   bool isEquality() const {
   1114     return isEquality(getPredicate());
   1115   }
   1116 
   1117   /// @returns true if the predicate of this ICmpInst is commutative
   1118   /// \brief Determine if this relation is commutative.
   1119   bool isCommutative() const { return isEquality(); }
   1120 
   1121   /// isRelational - Return true if the predicate is relational (not EQ or NE).
   1122   ///
   1123   bool isRelational() const {
   1124     return !isEquality();
   1125   }
   1126 
   1127   /// isRelational - Return true if the predicate is relational (not EQ or NE).
   1128   ///
   1129   static bool isRelational(Predicate P) {
   1130     return !isEquality(P);
   1131   }
   1132 
   1133   /// Initialize a set of values that all satisfy the predicate with C.
   1134   /// \brief Make a ConstantRange for a relation with a constant value.
   1135   static ConstantRange makeConstantRange(Predicate pred, const APInt &C);
   1136 
   1137   /// Exchange the two operands to this instruction in such a way that it does
   1138   /// not modify the semantics of the instruction. The predicate value may be
   1139   /// changed to retain the same result if the predicate is order dependent
   1140   /// (e.g. ult).
   1141   /// \brief Swap operands and adjust predicate.
   1142   void swapOperands() {
   1143     setPredicate(getSwappedPredicate());
   1144     Op<0>().swap(Op<1>());
   1145   }
   1146 
   1147   // Methods for support type inquiry through isa, cast, and dyn_cast:
   1148   static inline bool classof(const Instruction *I) {
   1149     return I->getOpcode() == Instruction::ICmp;
   1150   }
   1151   static inline bool classof(const Value *V) {
   1152     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   1153   }
   1154 
   1155 };
   1156 
   1157 //===----------------------------------------------------------------------===//
   1158 //                               FCmpInst Class
   1159 //===----------------------------------------------------------------------===//
   1160 
   1161 /// This instruction compares its operands according to the predicate given
   1162 /// to the constructor. It only operates on floating point values or packed
   1163 /// vectors of floating point values. The operands must be identical types.
   1164 /// \brief Represents a floating point comparison operator.
   1165 class FCmpInst: public CmpInst {
   1166 protected:
   1167   /// \brief Clone an identical FCmpInst
   1168   FCmpInst *clone_impl() const override;
   1169 public:
   1170   /// \brief Constructor with insert-before-instruction semantics.
   1171   FCmpInst(
   1172     Instruction *InsertBefore, ///< Where to insert
   1173     Predicate pred,  ///< The predicate to use for the comparison
   1174     Value *LHS,      ///< The left-hand-side of the expression
   1175     Value *RHS,      ///< The right-hand-side of the expression
   1176     const Twine &NameStr = ""  ///< Name of the instruction
   1177   ) : CmpInst(makeCmpResultType(LHS->getType()),
   1178               Instruction::FCmp, pred, LHS, RHS, NameStr,
   1179               InsertBefore) {
   1180     assert(pred <= FCmpInst::LAST_FCMP_PREDICATE &&
   1181            "Invalid FCmp predicate value");
   1182     assert(getOperand(0)->getType() == getOperand(1)->getType() &&
   1183            "Both operands to FCmp instruction are not of the same type!");
   1184     // Check that the operands are the right type
   1185     assert(getOperand(0)->getType()->isFPOrFPVectorTy() &&
   1186            "Invalid operand types for FCmp instruction");
   1187   }
   1188 
   1189   /// \brief Constructor with insert-at-end semantics.
   1190   FCmpInst(
   1191     BasicBlock &InsertAtEnd, ///< Block to insert into.
   1192     Predicate pred,  ///< The predicate to use for the comparison
   1193     Value *LHS,      ///< The left-hand-side of the expression
   1194     Value *RHS,      ///< The right-hand-side of the expression
   1195     const Twine &NameStr = ""  ///< Name of the instruction
   1196   ) : CmpInst(makeCmpResultType(LHS->getType()),
   1197               Instruction::FCmp, pred, LHS, RHS, NameStr,
   1198               &InsertAtEnd) {
   1199     assert(pred <= FCmpInst::LAST_FCMP_PREDICATE &&
   1200            "Invalid FCmp predicate value");
   1201     assert(getOperand(0)->getType() == getOperand(1)->getType() &&
   1202            "Both operands to FCmp instruction are not of the same type!");
   1203     // Check that the operands are the right type
   1204     assert(getOperand(0)->getType()->isFPOrFPVectorTy() &&
   1205            "Invalid operand types for FCmp instruction");
   1206   }
   1207 
   1208   /// \brief Constructor with no-insertion semantics
   1209   FCmpInst(
   1210     Predicate pred, ///< The predicate to use for the comparison
   1211     Value *LHS,     ///< The left-hand-side of the expression
   1212     Value *RHS,     ///< The right-hand-side of the expression
   1213     const Twine &NameStr = "" ///< Name of the instruction
   1214   ) : CmpInst(makeCmpResultType(LHS->getType()),
   1215               Instruction::FCmp, pred, LHS, RHS, NameStr) {
   1216     assert(pred <= FCmpInst::LAST_FCMP_PREDICATE &&
   1217            "Invalid FCmp predicate value");
   1218     assert(getOperand(0)->getType() == getOperand(1)->getType() &&
   1219            "Both operands to FCmp instruction are not of the same type!");
   1220     // Check that the operands are the right type
   1221     assert(getOperand(0)->getType()->isFPOrFPVectorTy() &&
   1222            "Invalid operand types for FCmp instruction");
   1223   }
   1224 
   1225   /// @returns true if the predicate of this instruction is EQ or NE.
   1226   /// \brief Determine if this is an equality predicate.
   1227   static bool isEquality(Predicate Pred) {
   1228     return Pred == FCMP_OEQ || Pred == FCMP_ONE || Pred == FCMP_UEQ ||
   1229            Pred == FCMP_UNE;
   1230   }
   1231 
   1232   /// @returns true if the predicate of this instruction is EQ or NE.
   1233   /// \brief Determine if this is an equality predicate.
   1234   bool isEquality() const { return isEquality(getPredicate()); }
   1235 
   1236   /// @returns true if the predicate of this instruction is commutative.
   1237   /// \brief Determine if this is a commutative predicate.
   1238   bool isCommutative() const {
   1239     return isEquality() ||
   1240            getPredicate() == FCMP_FALSE ||
   1241            getPredicate() == FCMP_TRUE ||
   1242            getPredicate() == FCMP_ORD ||
   1243            getPredicate() == FCMP_UNO;
   1244   }
   1245 
   1246   /// @returns true if the predicate is relational (not EQ or NE).
   1247   /// \brief Determine if this a relational predicate.
   1248   bool isRelational() const { return !isEquality(); }
   1249 
   1250   /// Exchange the two operands to this instruction in such a way that it does
   1251   /// not modify the semantics of the instruction. The predicate value may be
   1252   /// changed to retain the same result if the predicate is order dependent
   1253   /// (e.g. ult).
   1254   /// \brief Swap operands and adjust predicate.
   1255   void swapOperands() {
   1256     setPredicate(getSwappedPredicate());
   1257     Op<0>().swap(Op<1>());
   1258   }
   1259 
   1260   /// \brief Methods for support type inquiry through isa, cast, and dyn_cast:
   1261   static inline bool classof(const Instruction *I) {
   1262     return I->getOpcode() == Instruction::FCmp;
   1263   }
   1264   static inline bool classof(const Value *V) {
   1265     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   1266   }
   1267 };
   1268 
   1269 //===----------------------------------------------------------------------===//
   1270 /// CallInst - This class represents a function call, abstracting a target
   1271 /// machine's calling convention.  This class uses low bit of the SubClassData
   1272 /// field to indicate whether or not this is a tail call.  The rest of the bits
   1273 /// hold the calling convention of the call.
   1274 ///
   1275 class CallInst : public Instruction {
   1276   AttributeSet AttributeList; ///< parameter attributes for call
   1277   CallInst(const CallInst &CI);
   1278   void init(Value *Func, ArrayRef<Value *> Args, const Twine &NameStr);
   1279   void init(Value *Func, const Twine &NameStr);
   1280 
   1281   /// Construct a CallInst given a range of arguments.
   1282   /// \brief Construct a CallInst from a range of arguments
   1283   inline CallInst(Value *Func, ArrayRef<Value *> Args,
   1284                   const Twine &NameStr, Instruction *InsertBefore);
   1285 
   1286   /// Construct a CallInst given a range of arguments.
   1287   /// \brief Construct a CallInst from a range of arguments
   1288   inline CallInst(Value *Func, ArrayRef<Value *> Args,
   1289                   const Twine &NameStr, BasicBlock *InsertAtEnd);
   1290 
   1291   explicit CallInst(Value *F, const Twine &NameStr,
   1292                     Instruction *InsertBefore);
   1293   CallInst(Value *F, const Twine &NameStr, BasicBlock *InsertAtEnd);
   1294 protected:
   1295   CallInst *clone_impl() const override;
   1296 public:
   1297   static CallInst *Create(Value *Func,
   1298                           ArrayRef<Value *> Args,
   1299                           const Twine &NameStr = "",
   1300                           Instruction *InsertBefore = nullptr) {
   1301     return new(unsigned(Args.size() + 1))
   1302       CallInst(Func, Args, NameStr, InsertBefore);
   1303   }
   1304   static CallInst *Create(Value *Func,
   1305                           ArrayRef<Value *> Args,
   1306                           const Twine &NameStr, BasicBlock *InsertAtEnd) {
   1307     return new(unsigned(Args.size() + 1))
   1308       CallInst(Func, Args, NameStr, InsertAtEnd);
   1309   }
   1310   static CallInst *Create(Value *F, const Twine &NameStr = "",
   1311                           Instruction *InsertBefore = nullptr) {
   1312     return new(1) CallInst(F, NameStr, InsertBefore);
   1313   }
   1314   static CallInst *Create(Value *F, const Twine &NameStr,
   1315                           BasicBlock *InsertAtEnd) {
   1316     return new(1) CallInst(F, NameStr, InsertAtEnd);
   1317   }
   1318   /// CreateMalloc - Generate the IR for a call to malloc:
   1319   /// 1. Compute the malloc call's argument as the specified type's size,
   1320   ///    possibly multiplied by the array size if the array size is not
   1321   ///    constant 1.
   1322   /// 2. Call malloc with that argument.
   1323   /// 3. Bitcast the result of the malloc call to the specified type.
   1324   static Instruction *CreateMalloc(Instruction *InsertBefore,
   1325                                    Type *IntPtrTy, Type *AllocTy,
   1326                                    Value *AllocSize, Value *ArraySize = nullptr,
   1327                                    Function* MallocF = nullptr,
   1328                                    const Twine &Name = "");
   1329   static Instruction *CreateMalloc(BasicBlock *InsertAtEnd,
   1330                                    Type *IntPtrTy, Type *AllocTy,
   1331                                    Value *AllocSize, Value *ArraySize = nullptr,
   1332                                    Function* MallocF = nullptr,
   1333                                    const Twine &Name = "");
   1334   /// CreateFree - Generate the IR for a call to the builtin free function.
   1335   static Instruction* CreateFree(Value* Source, Instruction *InsertBefore);
   1336   static Instruction* CreateFree(Value* Source, BasicBlock *InsertAtEnd);
   1337 
   1338   ~CallInst() override;
   1339 
   1340   Type *getFunctionType() const {
   1341     return cast<PointerType>(getCalledValue()->getType())->getElementType();
   1342   }
   1343 
   1344   // Note that 'musttail' implies 'tail'.
   1345   enum TailCallKind { TCK_None = 0, TCK_Tail = 1, TCK_MustTail = 2 };
   1346   TailCallKind getTailCallKind() const {
   1347     return TailCallKind(getSubclassDataFromInstruction() & 3);
   1348   }
   1349   bool isTailCall() const {
   1350     return (getSubclassDataFromInstruction() & 3) != TCK_None;
   1351   }
   1352   bool isMustTailCall() const {
   1353     return (getSubclassDataFromInstruction() & 3) == TCK_MustTail;
   1354   }
   1355   void setTailCall(bool isTC = true) {
   1356     setInstructionSubclassData((getSubclassDataFromInstruction() & ~3) |
   1357                                unsigned(isTC ? TCK_Tail : TCK_None));
   1358   }
   1359   void setTailCallKind(TailCallKind TCK) {
   1360     setInstructionSubclassData((getSubclassDataFromInstruction() & ~3) |
   1361                                unsigned(TCK));
   1362   }
   1363 
   1364   /// Provide fast operand accessors
   1365   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
   1366 
   1367   /// getNumArgOperands - Return the number of call arguments.
   1368   ///
   1369   unsigned getNumArgOperands() const { return getNumOperands() - 1; }
   1370 
   1371   /// getArgOperand/setArgOperand - Return/set the i-th call argument.
   1372   ///
   1373   Value *getArgOperand(unsigned i) const { return getOperand(i); }
   1374   void setArgOperand(unsigned i, Value *v) { setOperand(i, v); }
   1375 
   1376   /// arg_operands - iteration adapter for range-for loops.
   1377   iterator_range<op_iterator> arg_operands() {
   1378     // The last operand in the op list is the callee - it's not one of the args
   1379     // so we don't want to iterate over it.
   1380     return iterator_range<op_iterator>(op_begin(), op_end() - 1);
   1381   }
   1382 
   1383   /// arg_operands - iteration adapter for range-for loops.
   1384   iterator_range<const_op_iterator> arg_operands() const {
   1385     return iterator_range<const_op_iterator>(op_begin(), op_end() - 1);
   1386   }
   1387 
   1388   /// \brief Wrappers for getting the \c Use of a call argument.
   1389   const Use &getArgOperandUse(unsigned i) const { return getOperandUse(i); }
   1390   Use &getArgOperandUse(unsigned i) { return getOperandUse(i); }
   1391 
   1392   /// getCallingConv/setCallingConv - Get or set the calling convention of this
   1393   /// function call.
   1394   CallingConv::ID getCallingConv() const {
   1395     return static_cast<CallingConv::ID>(getSubclassDataFromInstruction() >> 2);
   1396   }
   1397   void setCallingConv(CallingConv::ID CC) {
   1398     setInstructionSubclassData((getSubclassDataFromInstruction() & 3) |
   1399                                (static_cast<unsigned>(CC) << 2));
   1400   }
   1401 
   1402   /// getAttributes - Return the parameter attributes for this call.
   1403   ///
   1404   const AttributeSet &getAttributes() const { return AttributeList; }
   1405 
   1406   /// setAttributes - Set the parameter attributes for this call.
   1407   ///
   1408   void setAttributes(const AttributeSet &Attrs) { AttributeList = Attrs; }
   1409 
   1410   /// addAttribute - adds the attribute to the list of attributes.
   1411   void addAttribute(unsigned i, Attribute::AttrKind attr);
   1412 
   1413   /// removeAttribute - removes the attribute from the list of attributes.
   1414   void removeAttribute(unsigned i, Attribute attr);
   1415 
   1416   /// \brief adds the dereferenceable attribute to the list of attributes.
   1417   void addDereferenceableAttr(unsigned i, uint64_t Bytes);
   1418 
   1419   /// \brief adds the dereferenceable_or_null attribute to the list of
   1420   /// attributes.
   1421   void addDereferenceableOrNullAttr(unsigned i, uint64_t Bytes);
   1422 
   1423   /// \brief Determine whether this call has the given attribute.
   1424   bool hasFnAttr(Attribute::AttrKind A) const {
   1425     assert(A != Attribute::NoBuiltin &&
   1426            "Use CallInst::isNoBuiltin() to check for Attribute::NoBuiltin");
   1427     return hasFnAttrImpl(A);
   1428   }
   1429 
   1430   /// \brief Determine whether the call or the callee has the given attributes.
   1431   bool paramHasAttr(unsigned i, Attribute::AttrKind A) const;
   1432 
   1433   /// \brief Extract the alignment for a call or parameter (0=unknown).
   1434   unsigned getParamAlignment(unsigned i) const {
   1435     return AttributeList.getParamAlignment(i);
   1436   }
   1437 
   1438   /// \brief Extract the number of dereferenceable bytes for a call or
   1439   /// parameter (0=unknown).
   1440   uint64_t getDereferenceableBytes(unsigned i) const {
   1441     return AttributeList.getDereferenceableBytes(i);
   1442   }
   1443 
   1444   /// \brief Return true if the call should not be treated as a call to a
   1445   /// builtin.
   1446   bool isNoBuiltin() const {
   1447     return hasFnAttrImpl(Attribute::NoBuiltin) &&
   1448       !hasFnAttrImpl(Attribute::Builtin);
   1449   }
   1450 
   1451   /// \brief Return true if the call should not be inlined.
   1452   bool isNoInline() const { return hasFnAttr(Attribute::NoInline); }
   1453   void setIsNoInline() {
   1454     addAttribute(AttributeSet::FunctionIndex, Attribute::NoInline);
   1455   }
   1456 
   1457   /// \brief Return true if the call can return twice
   1458   bool canReturnTwice() const {
   1459     return hasFnAttr(Attribute::ReturnsTwice);
   1460   }
   1461   void setCanReturnTwice() {
   1462     addAttribute(AttributeSet::FunctionIndex, Attribute::ReturnsTwice);
   1463   }
   1464 
   1465   /// \brief Determine if the call does not access memory.
   1466   bool doesNotAccessMemory() const {
   1467     return hasFnAttr(Attribute::ReadNone);
   1468   }
   1469   void setDoesNotAccessMemory() {
   1470     addAttribute(AttributeSet::FunctionIndex, Attribute::ReadNone);
   1471   }
   1472 
   1473   /// \brief Determine if the call does not access or only reads memory.
   1474   bool onlyReadsMemory() const {
   1475     return doesNotAccessMemory() || hasFnAttr(Attribute::ReadOnly);
   1476   }
   1477   void setOnlyReadsMemory() {
   1478     addAttribute(AttributeSet::FunctionIndex, Attribute::ReadOnly);
   1479   }
   1480 
   1481   /// \brief Determine if the call cannot return.
   1482   bool doesNotReturn() const { return hasFnAttr(Attribute::NoReturn); }
   1483   void setDoesNotReturn() {
   1484     addAttribute(AttributeSet::FunctionIndex, Attribute::NoReturn);
   1485   }
   1486 
   1487   /// \brief Determine if the call cannot unwind.
   1488   bool doesNotThrow() const { return hasFnAttr(Attribute::NoUnwind); }
   1489   void setDoesNotThrow() {
   1490     addAttribute(AttributeSet::FunctionIndex, Attribute::NoUnwind);
   1491   }
   1492 
   1493   /// \brief Determine if the call cannot be duplicated.
   1494   bool cannotDuplicate() const {return hasFnAttr(Attribute::NoDuplicate); }
   1495   void setCannotDuplicate() {
   1496     addAttribute(AttributeSet::FunctionIndex, Attribute::NoDuplicate);
   1497   }
   1498 
   1499   /// \brief Determine if the call returns a structure through first
   1500   /// pointer argument.
   1501   bool hasStructRetAttr() const {
   1502     // Be friendly and also check the callee.
   1503     return paramHasAttr(1, Attribute::StructRet);
   1504   }
   1505 
   1506   /// \brief Determine if any call argument is an aggregate passed by value.
   1507   bool hasByValArgument() const {
   1508     return AttributeList.hasAttrSomewhere(Attribute::ByVal);
   1509   }
   1510 
   1511   /// getCalledFunction - Return the function called, or null if this is an
   1512   /// indirect function invocation.
   1513   ///
   1514   Function *getCalledFunction() const {
   1515     return dyn_cast<Function>(Op<-1>());
   1516   }
   1517 
   1518   /// getCalledValue - Get a pointer to the function that is invoked by this
   1519   /// instruction.
   1520   const Value *getCalledValue() const { return Op<-1>(); }
   1521         Value *getCalledValue()       { return Op<-1>(); }
   1522 
   1523   /// setCalledFunction - Set the function called.
   1524   void setCalledFunction(Value* Fn) {
   1525     Op<-1>() = Fn;
   1526   }
   1527 
   1528   /// isInlineAsm - Check if this call is an inline asm statement.
   1529   bool isInlineAsm() const {
   1530     return isa<InlineAsm>(Op<-1>());
   1531   }
   1532 
   1533   // Methods for support type inquiry through isa, cast, and dyn_cast:
   1534   static inline bool classof(const Instruction *I) {
   1535     return I->getOpcode() == Instruction::Call;
   1536   }
   1537   static inline bool classof(const Value *V) {
   1538     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   1539   }
   1540 private:
   1541 
   1542   bool hasFnAttrImpl(Attribute::AttrKind A) const;
   1543 
   1544   // Shadow Instruction::setInstructionSubclassData with a private forwarding
   1545   // method so that subclasses cannot accidentally use it.
   1546   void setInstructionSubclassData(unsigned short D) {
   1547     Instruction::setInstructionSubclassData(D);
   1548   }
   1549 };
   1550 
   1551 template <>
   1552 struct OperandTraits<CallInst> : public VariadicOperandTraits<CallInst, 1> {
   1553 };
   1554 
   1555 CallInst::CallInst(Value *Func, ArrayRef<Value *> Args,
   1556                    const Twine &NameStr, BasicBlock *InsertAtEnd)
   1557   : Instruction(cast<FunctionType>(cast<PointerType>(Func->getType())
   1558                                    ->getElementType())->getReturnType(),
   1559                 Instruction::Call,
   1560                 OperandTraits<CallInst>::op_end(this) - (Args.size() + 1),
   1561                 unsigned(Args.size() + 1), InsertAtEnd) {
   1562   init(Func, Args, NameStr);
   1563 }
   1564 
   1565 CallInst::CallInst(Value *Func, ArrayRef<Value *> Args,
   1566                    const Twine &NameStr, Instruction *InsertBefore)
   1567   : Instruction(cast<FunctionType>(cast<PointerType>(Func->getType())
   1568                                    ->getElementType())->getReturnType(),
   1569                 Instruction::Call,
   1570                 OperandTraits<CallInst>::op_end(this) - (Args.size() + 1),
   1571                 unsigned(Args.size() + 1), InsertBefore) {
   1572   init(Func, Args, NameStr);
   1573 }
   1574 
   1575 
   1576 // Note: if you get compile errors about private methods then
   1577 //       please update your code to use the high-level operand
   1578 //       interfaces. See line 943 above.
   1579 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(CallInst, Value)
   1580 
   1581 //===----------------------------------------------------------------------===//
   1582 //                               SelectInst Class
   1583 //===----------------------------------------------------------------------===//
   1584 
   1585 /// SelectInst - This class represents the LLVM 'select' instruction.
   1586 ///
   1587 class SelectInst : public Instruction {
   1588   void init(Value *C, Value *S1, Value *S2) {
   1589     assert(!areInvalidOperands(C, S1, S2) && "Invalid operands for select");
   1590     Op<0>() = C;
   1591     Op<1>() = S1;
   1592     Op<2>() = S2;
   1593   }
   1594 
   1595   SelectInst(Value *C, Value *S1, Value *S2, const Twine &NameStr,
   1596              Instruction *InsertBefore)
   1597     : Instruction(S1->getType(), Instruction::Select,
   1598                   &Op<0>(), 3, InsertBefore) {
   1599     init(C, S1, S2);
   1600     setName(NameStr);
   1601   }
   1602   SelectInst(Value *C, Value *S1, Value *S2, const Twine &NameStr,
   1603              BasicBlock *InsertAtEnd)
   1604     : Instruction(S1->getType(), Instruction::Select,
   1605                   &Op<0>(), 3, InsertAtEnd) {
   1606     init(C, S1, S2);
   1607     setName(NameStr);
   1608   }
   1609 protected:
   1610   SelectInst *clone_impl() const override;
   1611 public:
   1612   static SelectInst *Create(Value *C, Value *S1, Value *S2,
   1613                             const Twine &NameStr = "",
   1614                             Instruction *InsertBefore = nullptr) {
   1615     return new(3) SelectInst(C, S1, S2, NameStr, InsertBefore);
   1616   }
   1617   static SelectInst *Create(Value *C, Value *S1, Value *S2,
   1618                             const Twine &NameStr,
   1619                             BasicBlock *InsertAtEnd) {
   1620     return new(3) SelectInst(C, S1, S2, NameStr, InsertAtEnd);
   1621   }
   1622 
   1623   const Value *getCondition() const { return Op<0>(); }
   1624   const Value *getTrueValue() const { return Op<1>(); }
   1625   const Value *getFalseValue() const { return Op<2>(); }
   1626   Value *getCondition() { return Op<0>(); }
   1627   Value *getTrueValue() { return Op<1>(); }
   1628   Value *getFalseValue() { return Op<2>(); }
   1629 
   1630   /// areInvalidOperands - Return a string if the specified operands are invalid
   1631   /// for a select operation, otherwise return null.
   1632   static const char *areInvalidOperands(Value *Cond, Value *True, Value *False);
   1633 
   1634   /// Transparently provide more efficient getOperand methods.
   1635   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
   1636 
   1637   OtherOps getOpcode() const {
   1638     return static_cast<OtherOps>(Instruction::getOpcode());
   1639   }
   1640 
   1641   // Methods for support type inquiry through isa, cast, and dyn_cast:
   1642   static inline bool classof(const Instruction *I) {
   1643     return I->getOpcode() == Instruction::Select;
   1644   }
   1645   static inline bool classof(const Value *V) {
   1646     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   1647   }
   1648 };
   1649 
   1650 template <>
   1651 struct OperandTraits<SelectInst> : public FixedNumOperandTraits<SelectInst, 3> {
   1652 };
   1653 
   1654 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(SelectInst, Value)
   1655 
   1656 //===----------------------------------------------------------------------===//
   1657 //                                VAArgInst Class
   1658 //===----------------------------------------------------------------------===//
   1659 
   1660 /// VAArgInst - This class represents the va_arg llvm instruction, which returns
   1661 /// an argument of the specified type given a va_list and increments that list
   1662 ///
   1663 class VAArgInst : public UnaryInstruction {
   1664 protected:
   1665   VAArgInst *clone_impl() const override;
   1666 
   1667 public:
   1668   VAArgInst(Value *List, Type *Ty, const Twine &NameStr = "",
   1669              Instruction *InsertBefore = nullptr)
   1670     : UnaryInstruction(Ty, VAArg, List, InsertBefore) {
   1671     setName(NameStr);
   1672   }
   1673   VAArgInst(Value *List, Type *Ty, const Twine &NameStr,
   1674             BasicBlock *InsertAtEnd)
   1675     : UnaryInstruction(Ty, VAArg, List, InsertAtEnd) {
   1676     setName(NameStr);
   1677   }
   1678 
   1679   Value *getPointerOperand() { return getOperand(0); }
   1680   const Value *getPointerOperand() const { return getOperand(0); }
   1681   static unsigned getPointerOperandIndex() { return 0U; }
   1682 
   1683   // Methods for support type inquiry through isa, cast, and dyn_cast:
   1684   static inline bool classof(const Instruction *I) {
   1685     return I->getOpcode() == VAArg;
   1686   }
   1687   static inline bool classof(const Value *V) {
   1688     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   1689   }
   1690 };
   1691 
   1692 //===----------------------------------------------------------------------===//
   1693 //                                ExtractElementInst Class
   1694 //===----------------------------------------------------------------------===//
   1695 
   1696 /// ExtractElementInst - This instruction extracts a single (scalar)
   1697 /// element from a VectorType value
   1698 ///
   1699 class ExtractElementInst : public Instruction {
   1700   ExtractElementInst(Value *Vec, Value *Idx, const Twine &NameStr = "",
   1701                      Instruction *InsertBefore = nullptr);
   1702   ExtractElementInst(Value *Vec, Value *Idx, const Twine &NameStr,
   1703                      BasicBlock *InsertAtEnd);
   1704 protected:
   1705   ExtractElementInst *clone_impl() const override;
   1706 
   1707 public:
   1708   static ExtractElementInst *Create(Value *Vec, Value *Idx,
   1709                                    const Twine &NameStr = "",
   1710                                    Instruction *InsertBefore = nullptr) {
   1711     return new(2) ExtractElementInst(Vec, Idx, NameStr, InsertBefore);
   1712   }
   1713   static ExtractElementInst *Create(Value *Vec, Value *Idx,
   1714                                    const Twine &NameStr,
   1715                                    BasicBlock *InsertAtEnd) {
   1716     return new(2) ExtractElementInst(Vec, Idx, NameStr, InsertAtEnd);
   1717   }
   1718 
   1719   /// isValidOperands - Return true if an extractelement instruction can be
   1720   /// formed with the specified operands.
   1721   static bool isValidOperands(const Value *Vec, const Value *Idx);
   1722 
   1723   Value *getVectorOperand() { return Op<0>(); }
   1724   Value *getIndexOperand() { return Op<1>(); }
   1725   const Value *getVectorOperand() const { return Op<0>(); }
   1726   const Value *getIndexOperand() const { return Op<1>(); }
   1727 
   1728   VectorType *getVectorOperandType() const {
   1729     return cast<VectorType>(getVectorOperand()->getType());
   1730   }
   1731 
   1732 
   1733   /// Transparently provide more efficient getOperand methods.
   1734   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
   1735 
   1736   // Methods for support type inquiry through isa, cast, and dyn_cast:
   1737   static inline bool classof(const Instruction *I) {
   1738     return I->getOpcode() == Instruction::ExtractElement;
   1739   }
   1740   static inline bool classof(const Value *V) {
   1741     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   1742   }
   1743 };
   1744 
   1745 template <>
   1746 struct OperandTraits<ExtractElementInst> :
   1747   public FixedNumOperandTraits<ExtractElementInst, 2> {
   1748 };
   1749 
   1750 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ExtractElementInst, Value)
   1751 
   1752 //===----------------------------------------------------------------------===//
   1753 //                                InsertElementInst Class
   1754 //===----------------------------------------------------------------------===//
   1755 
   1756 /// InsertElementInst - This instruction inserts a single (scalar)
   1757 /// element into a VectorType value
   1758 ///
   1759 class InsertElementInst : public Instruction {
   1760   InsertElementInst(Value *Vec, Value *NewElt, Value *Idx,
   1761                     const Twine &NameStr = "",
   1762                     Instruction *InsertBefore = nullptr);
   1763   InsertElementInst(Value *Vec, Value *NewElt, Value *Idx,
   1764                     const Twine &NameStr, BasicBlock *InsertAtEnd);
   1765 protected:
   1766   InsertElementInst *clone_impl() const override;
   1767 
   1768 public:
   1769   static InsertElementInst *Create(Value *Vec, Value *NewElt, Value *Idx,
   1770                                    const Twine &NameStr = "",
   1771                                    Instruction *InsertBefore = nullptr) {
   1772     return new(3) InsertElementInst(Vec, NewElt, Idx, NameStr, InsertBefore);
   1773   }
   1774   static InsertElementInst *Create(Value *Vec, Value *NewElt, Value *Idx,
   1775                                    const Twine &NameStr,
   1776                                    BasicBlock *InsertAtEnd) {
   1777     return new(3) InsertElementInst(Vec, NewElt, Idx, NameStr, InsertAtEnd);
   1778   }
   1779 
   1780   /// isValidOperands - Return true if an insertelement instruction can be
   1781   /// formed with the specified operands.
   1782   static bool isValidOperands(const Value *Vec, const Value *NewElt,
   1783                               const Value *Idx);
   1784 
   1785   /// getType - Overload to return most specific vector type.
   1786   ///
   1787   VectorType *getType() const {
   1788     return cast<VectorType>(Instruction::getType());
   1789   }
   1790 
   1791   /// Transparently provide more efficient getOperand methods.
   1792   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
   1793 
   1794   // Methods for support type inquiry through isa, cast, and dyn_cast:
   1795   static inline bool classof(const Instruction *I) {
   1796     return I->getOpcode() == Instruction::InsertElement;
   1797   }
   1798   static inline bool classof(const Value *V) {
   1799     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   1800   }
   1801 };
   1802 
   1803 template <>
   1804 struct OperandTraits<InsertElementInst> :
   1805   public FixedNumOperandTraits<InsertElementInst, 3> {
   1806 };
   1807 
   1808 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(InsertElementInst, Value)
   1809 
   1810 //===----------------------------------------------------------------------===//
   1811 //                           ShuffleVectorInst Class
   1812 //===----------------------------------------------------------------------===//
   1813 
   1814 /// ShuffleVectorInst - This instruction constructs a fixed permutation of two
   1815 /// input vectors.
   1816 ///
   1817 class ShuffleVectorInst : public Instruction {
   1818 protected:
   1819   ShuffleVectorInst *clone_impl() const override;
   1820 
   1821 public:
   1822   // allocate space for exactly three operands
   1823   void *operator new(size_t s) {
   1824     return User::operator new(s, 3);
   1825   }
   1826   ShuffleVectorInst(Value *V1, Value *V2, Value *Mask,
   1827                     const Twine &NameStr = "",
   1828                     Instruction *InsertBefor = nullptr);
   1829   ShuffleVectorInst(Value *V1, Value *V2, Value *Mask,
   1830                     const Twine &NameStr, BasicBlock *InsertAtEnd);
   1831 
   1832   /// isValidOperands - Return true if a shufflevector instruction can be
   1833   /// formed with the specified operands.
   1834   static bool isValidOperands(const Value *V1, const Value *V2,
   1835                               const Value *Mask);
   1836 
   1837   /// getType - Overload to return most specific vector type.
   1838   ///
   1839   VectorType *getType() const {
   1840     return cast<VectorType>(Instruction::getType());
   1841   }
   1842 
   1843   /// Transparently provide more efficient getOperand methods.
   1844   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
   1845 
   1846   Constant *getMask() const {
   1847     return cast<Constant>(getOperand(2));
   1848   }
   1849 
   1850   /// getMaskValue - Return the index from the shuffle mask for the specified
   1851   /// output result.  This is either -1 if the element is undef or a number less
   1852   /// than 2*numelements.
   1853   static int getMaskValue(Constant *Mask, unsigned i);
   1854 
   1855   int getMaskValue(unsigned i) const {
   1856     return getMaskValue(getMask(), i);
   1857   }
   1858 
   1859   /// getShuffleMask - Return the full mask for this instruction, where each
   1860   /// element is the element number and undef's are returned as -1.
   1861   static void getShuffleMask(Constant *Mask, SmallVectorImpl<int> &Result);
   1862 
   1863   void getShuffleMask(SmallVectorImpl<int> &Result) const {
   1864     return getShuffleMask(getMask(), Result);
   1865   }
   1866 
   1867   SmallVector<int, 16> getShuffleMask() const {
   1868     SmallVector<int, 16> Mask;
   1869     getShuffleMask(Mask);
   1870     return Mask;
   1871   }
   1872 
   1873 
   1874   // Methods for support type inquiry through isa, cast, and dyn_cast:
   1875   static inline bool classof(const Instruction *I) {
   1876     return I->getOpcode() == Instruction::ShuffleVector;
   1877   }
   1878   static inline bool classof(const Value *V) {
   1879     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   1880   }
   1881 };
   1882 
   1883 template <>
   1884 struct OperandTraits<ShuffleVectorInst> :
   1885   public FixedNumOperandTraits<ShuffleVectorInst, 3> {
   1886 };
   1887 
   1888 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ShuffleVectorInst, Value)
   1889 
   1890 //===----------------------------------------------------------------------===//
   1891 //                                ExtractValueInst Class
   1892 //===----------------------------------------------------------------------===//
   1893 
   1894 /// ExtractValueInst - This instruction extracts a struct member or array
   1895 /// element value from an aggregate value.
   1896 ///
   1897 class ExtractValueInst : public UnaryInstruction {
   1898   SmallVector<unsigned, 4> Indices;
   1899 
   1900   ExtractValueInst(const ExtractValueInst &EVI);
   1901   void init(ArrayRef<unsigned> Idxs, const Twine &NameStr);
   1902 
   1903   /// Constructors - Create a extractvalue instruction with a base aggregate
   1904   /// value and a list of indices.  The first ctor can optionally insert before
   1905   /// an existing instruction, the second appends the new instruction to the
   1906   /// specified BasicBlock.
   1907   inline ExtractValueInst(Value *Agg,
   1908                           ArrayRef<unsigned> Idxs,
   1909                           const Twine &NameStr,
   1910                           Instruction *InsertBefore);
   1911   inline ExtractValueInst(Value *Agg,
   1912                           ArrayRef<unsigned> Idxs,
   1913                           const Twine &NameStr, BasicBlock *InsertAtEnd);
   1914 
   1915   // allocate space for exactly one operand
   1916   void *operator new(size_t s) {
   1917     return User::operator new(s, 1);
   1918   }
   1919 protected:
   1920   ExtractValueInst *clone_impl() const override;
   1921 
   1922 public:
   1923   static ExtractValueInst *Create(Value *Agg,
   1924                                   ArrayRef<unsigned> Idxs,
   1925                                   const Twine &NameStr = "",
   1926                                   Instruction *InsertBefore = nullptr) {
   1927     return new
   1928       ExtractValueInst(Agg, Idxs, NameStr, InsertBefore);
   1929   }
   1930   static ExtractValueInst *Create(Value *Agg,
   1931                                   ArrayRef<unsigned> Idxs,
   1932                                   const Twine &NameStr,
   1933                                   BasicBlock *InsertAtEnd) {
   1934     return new ExtractValueInst(Agg, Idxs, NameStr, InsertAtEnd);
   1935   }
   1936 
   1937   /// getIndexedType - Returns the type of the element that would be extracted
   1938   /// with an extractvalue instruction with the specified parameters.
   1939   ///
   1940   /// Null is returned if the indices are invalid for the specified type.
   1941   static Type *getIndexedType(Type *Agg, ArrayRef<unsigned> Idxs);
   1942 
   1943   typedef const unsigned* idx_iterator;
   1944   inline idx_iterator idx_begin() const { return Indices.begin(); }
   1945   inline idx_iterator idx_end()   const { return Indices.end(); }
   1946   inline iterator_range<idx_iterator> indices() const {
   1947     return iterator_range<idx_iterator>(idx_begin(), idx_end());
   1948   }
   1949 
   1950   Value *getAggregateOperand() {
   1951     return getOperand(0);
   1952   }
   1953   const Value *getAggregateOperand() const {
   1954     return getOperand(0);
   1955   }
   1956   static unsigned getAggregateOperandIndex() {
   1957     return 0U;                      // get index for modifying correct operand
   1958   }
   1959 
   1960   ArrayRef<unsigned> getIndices() const {
   1961     return Indices;
   1962   }
   1963 
   1964   unsigned getNumIndices() const {
   1965     return (unsigned)Indices.size();
   1966   }
   1967 
   1968   bool hasIndices() const {
   1969     return true;
   1970   }
   1971 
   1972   // Methods for support type inquiry through isa, cast, and dyn_cast:
   1973   static inline bool classof(const Instruction *I) {
   1974     return I->getOpcode() == Instruction::ExtractValue;
   1975   }
   1976   static inline bool classof(const Value *V) {
   1977     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   1978   }
   1979 };
   1980 
   1981 ExtractValueInst::ExtractValueInst(Value *Agg,
   1982                                    ArrayRef<unsigned> Idxs,
   1983                                    const Twine &NameStr,
   1984                                    Instruction *InsertBefore)
   1985   : UnaryInstruction(checkGEPType(getIndexedType(Agg->getType(), Idxs)),
   1986                      ExtractValue, Agg, InsertBefore) {
   1987   init(Idxs, NameStr);
   1988 }
   1989 ExtractValueInst::ExtractValueInst(Value *Agg,
   1990                                    ArrayRef<unsigned> Idxs,
   1991                                    const Twine &NameStr,
   1992                                    BasicBlock *InsertAtEnd)
   1993   : UnaryInstruction(checkGEPType(getIndexedType(Agg->getType(), Idxs)),
   1994                      ExtractValue, Agg, InsertAtEnd) {
   1995   init(Idxs, NameStr);
   1996 }
   1997 
   1998 
   1999 //===----------------------------------------------------------------------===//
   2000 //                                InsertValueInst Class
   2001 //===----------------------------------------------------------------------===//
   2002 
   2003 /// InsertValueInst - This instruction inserts a struct field of array element
   2004 /// value into an aggregate value.
   2005 ///
   2006 class InsertValueInst : public Instruction {
   2007   SmallVector<unsigned, 4> Indices;
   2008 
   2009   void *operator new(size_t, unsigned) = delete;
   2010   InsertValueInst(const InsertValueInst &IVI);
   2011   void init(Value *Agg, Value *Val, ArrayRef<unsigned> Idxs,
   2012             const Twine &NameStr);
   2013 
   2014   /// Constructors - Create a insertvalue instruction with a base aggregate
   2015   /// value, a value to insert, and a list of indices.  The first ctor can
   2016   /// optionally insert before an existing instruction, the second appends
   2017   /// the new instruction to the specified BasicBlock.
   2018   inline InsertValueInst(Value *Agg, Value *Val,
   2019                          ArrayRef<unsigned> Idxs,
   2020                          const Twine &NameStr,
   2021                          Instruction *InsertBefore);
   2022   inline InsertValueInst(Value *Agg, Value *Val,
   2023                          ArrayRef<unsigned> Idxs,
   2024                          const Twine &NameStr, BasicBlock *InsertAtEnd);
   2025 
   2026   /// Constructors - These two constructors are convenience methods because one
   2027   /// and two index insertvalue instructions are so common.
   2028   InsertValueInst(Value *Agg, Value *Val,
   2029                   unsigned Idx, const Twine &NameStr = "",
   2030                   Instruction *InsertBefore = nullptr);
   2031   InsertValueInst(Value *Agg, Value *Val, unsigned Idx,
   2032                   const Twine &NameStr, BasicBlock *InsertAtEnd);
   2033 protected:
   2034   InsertValueInst *clone_impl() const override;
   2035 public:
   2036   // allocate space for exactly two operands
   2037   void *operator new(size_t s) {
   2038     return User::operator new(s, 2);
   2039   }
   2040 
   2041   static InsertValueInst *Create(Value *Agg, Value *Val,
   2042                                  ArrayRef<unsigned> Idxs,
   2043                                  const Twine &NameStr = "",
   2044                                  Instruction *InsertBefore = nullptr) {
   2045     return new InsertValueInst(Agg, Val, Idxs, NameStr, InsertBefore);
   2046   }
   2047   static InsertValueInst *Create(Value *Agg, Value *Val,
   2048                                  ArrayRef<unsigned> Idxs,
   2049                                  const Twine &NameStr,
   2050                                  BasicBlock *InsertAtEnd) {
   2051     return new InsertValueInst(Agg, Val, Idxs, NameStr, InsertAtEnd);
   2052   }
   2053 
   2054   /// Transparently provide more efficient getOperand methods.
   2055   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
   2056 
   2057   typedef const unsigned* idx_iterator;
   2058   inline idx_iterator idx_begin() const { return Indices.begin(); }
   2059   inline idx_iterator idx_end()   const { return Indices.end(); }
   2060   inline iterator_range<idx_iterator> indices() const {
   2061     return iterator_range<idx_iterator>(idx_begin(), idx_end());
   2062   }
   2063 
   2064   Value *getAggregateOperand() {
   2065     return getOperand(0);
   2066   }
   2067   const Value *getAggregateOperand() const {
   2068     return getOperand(0);
   2069   }
   2070   static unsigned getAggregateOperandIndex() {
   2071     return 0U;                      // get index for modifying correct operand
   2072   }
   2073 
   2074   Value *getInsertedValueOperand() {
   2075     return getOperand(1);
   2076   }
   2077   const Value *getInsertedValueOperand() const {
   2078     return getOperand(1);
   2079   }
   2080   static unsigned getInsertedValueOperandIndex() {
   2081     return 1U;                      // get index for modifying correct operand
   2082   }
   2083 
   2084   ArrayRef<unsigned> getIndices() const {
   2085     return Indices;
   2086   }
   2087 
   2088   unsigned getNumIndices() const {
   2089     return (unsigned)Indices.size();
   2090   }
   2091 
   2092   bool hasIndices() const {
   2093     return true;
   2094   }
   2095 
   2096   // Methods for support type inquiry through isa, cast, and dyn_cast:
   2097   static inline bool classof(const Instruction *I) {
   2098     return I->getOpcode() == Instruction::InsertValue;
   2099   }
   2100   static inline bool classof(const Value *V) {
   2101     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   2102   }
   2103 };
   2104 
   2105 template <>
   2106 struct OperandTraits<InsertValueInst> :
   2107   public FixedNumOperandTraits<InsertValueInst, 2> {
   2108 };
   2109 
   2110 InsertValueInst::InsertValueInst(Value *Agg,
   2111                                  Value *Val,
   2112                                  ArrayRef<unsigned> Idxs,
   2113                                  const Twine &NameStr,
   2114                                  Instruction *InsertBefore)
   2115   : Instruction(Agg->getType(), InsertValue,
   2116                 OperandTraits<InsertValueInst>::op_begin(this),
   2117                 2, InsertBefore) {
   2118   init(Agg, Val, Idxs, NameStr);
   2119 }
   2120 InsertValueInst::InsertValueInst(Value *Agg,
   2121                                  Value *Val,
   2122                                  ArrayRef<unsigned> Idxs,
   2123                                  const Twine &NameStr,
   2124                                  BasicBlock *InsertAtEnd)
   2125   : Instruction(Agg->getType(), InsertValue,
   2126                 OperandTraits<InsertValueInst>::op_begin(this),
   2127                 2, InsertAtEnd) {
   2128   init(Agg, Val, Idxs, NameStr);
   2129 }
   2130 
   2131 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(InsertValueInst, Value)
   2132 
   2133 //===----------------------------------------------------------------------===//
   2134 //                               PHINode Class
   2135 //===----------------------------------------------------------------------===//
   2136 
   2137 // PHINode - The PHINode class is used to represent the magical mystical PHI
   2138 // node, that can not exist in nature, but can be synthesized in a computer
   2139 // scientist's overactive imagination.
   2140 //
   2141 class PHINode : public Instruction {
   2142   void *operator new(size_t, unsigned) = delete;
   2143   /// ReservedSpace - The number of operands actually allocated.  NumOperands is
   2144   /// the number actually in use.
   2145   unsigned ReservedSpace;
   2146   PHINode(const PHINode &PN);
   2147   // allocate space for exactly zero operands
   2148   void *operator new(size_t s) {
   2149     return User::operator new(s, 0);
   2150   }
   2151   explicit PHINode(Type *Ty, unsigned NumReservedValues,
   2152                    const Twine &NameStr = "",
   2153                    Instruction *InsertBefore = nullptr)
   2154     : Instruction(Ty, Instruction::PHI, nullptr, 0, InsertBefore),
   2155       ReservedSpace(NumReservedValues) {
   2156     setName(NameStr);
   2157     OperandList = allocHungoffUses(ReservedSpace);
   2158   }
   2159 
   2160   PHINode(Type *Ty, unsigned NumReservedValues, const Twine &NameStr,
   2161           BasicBlock *InsertAtEnd)
   2162     : Instruction(Ty, Instruction::PHI, nullptr, 0, InsertAtEnd),
   2163       ReservedSpace(NumReservedValues) {
   2164     setName(NameStr);
   2165     OperandList = allocHungoffUses(ReservedSpace);
   2166   }
   2167 protected:
   2168   // allocHungoffUses - this is more complicated than the generic
   2169   // User::allocHungoffUses, because we have to allocate Uses for the incoming
   2170   // values and pointers to the incoming blocks, all in one allocation.
   2171   Use *allocHungoffUses(unsigned) const;
   2172 
   2173   PHINode *clone_impl() const override;
   2174 public:
   2175   /// Constructors - NumReservedValues is a hint for the number of incoming
   2176   /// edges that this phi node will have (use 0 if you really have no idea).
   2177   static PHINode *Create(Type *Ty, unsigned NumReservedValues,
   2178                          const Twine &NameStr = "",
   2179                          Instruction *InsertBefore = nullptr) {
   2180     return new PHINode(Ty, NumReservedValues, NameStr, InsertBefore);
   2181   }
   2182   static PHINode *Create(Type *Ty, unsigned NumReservedValues,
   2183                          const Twine &NameStr, BasicBlock *InsertAtEnd) {
   2184     return new PHINode(Ty, NumReservedValues, NameStr, InsertAtEnd);
   2185   }
   2186   ~PHINode() override;
   2187 
   2188   /// Provide fast operand accessors
   2189   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
   2190 
   2191   // Block iterator interface. This provides access to the list of incoming
   2192   // basic blocks, which parallels the list of incoming values.
   2193 
   2194   typedef BasicBlock **block_iterator;
   2195   typedef BasicBlock * const *const_block_iterator;
   2196 
   2197   block_iterator block_begin() {
   2198     Use::UserRef *ref =
   2199       reinterpret_cast<Use::UserRef*>(op_begin() + ReservedSpace);
   2200     return reinterpret_cast<block_iterator>(ref + 1);
   2201   }
   2202 
   2203   const_block_iterator block_begin() const {
   2204     const Use::UserRef *ref =
   2205       reinterpret_cast<const Use::UserRef*>(op_begin() + ReservedSpace);
   2206     return reinterpret_cast<const_block_iterator>(ref + 1);
   2207   }
   2208 
   2209   block_iterator block_end() {
   2210     return block_begin() + getNumOperands();
   2211   }
   2212 
   2213   const_block_iterator block_end() const {
   2214     return block_begin() + getNumOperands();
   2215   }
   2216 
   2217   op_range incoming_values() { return operands(); }
   2218 
   2219   /// getNumIncomingValues - Return the number of incoming edges
   2220   ///
   2221   unsigned getNumIncomingValues() const { return getNumOperands(); }
   2222 
   2223   /// getIncomingValue - Return incoming value number x
   2224   ///
   2225   Value *getIncomingValue(unsigned i) const {
   2226     return getOperand(i);
   2227   }
   2228   void setIncomingValue(unsigned i, Value *V) {
   2229     setOperand(i, V);
   2230   }
   2231   static unsigned getOperandNumForIncomingValue(unsigned i) {
   2232     return i;
   2233   }
   2234   static unsigned getIncomingValueNumForOperand(unsigned i) {
   2235     return i;
   2236   }
   2237 
   2238   /// getIncomingBlock - Return incoming basic block number @p i.
   2239   ///
   2240   BasicBlock *getIncomingBlock(unsigned i) const {
   2241     return block_begin()[i];
   2242   }
   2243 
   2244   /// getIncomingBlock - Return incoming basic block corresponding
   2245   /// to an operand of the PHI.
   2246   ///
   2247   BasicBlock *getIncomingBlock(const Use &U) const {
   2248     assert(this == U.getUser() && "Iterator doesn't point to PHI's Uses?");
   2249     return getIncomingBlock(unsigned(&U - op_begin()));
   2250   }
   2251 
   2252   /// getIncomingBlock - Return incoming basic block corresponding
   2253   /// to value use iterator.
   2254   ///
   2255   BasicBlock *getIncomingBlock(Value::const_user_iterator I) const {
   2256     return getIncomingBlock(I.getUse());
   2257   }
   2258 
   2259   void setIncomingBlock(unsigned i, BasicBlock *BB) {
   2260     block_begin()[i] = BB;
   2261   }
   2262 
   2263   /// addIncoming - Add an incoming value to the end of the PHI list
   2264   ///
   2265   void addIncoming(Value *V, BasicBlock *BB) {
   2266     assert(V && "PHI node got a null value!");
   2267     assert(BB && "PHI node got a null basic block!");
   2268     assert(getType() == V->getType() &&
   2269            "All operands to PHI node must be the same type as the PHI node!");
   2270     if (NumOperands == ReservedSpace)
   2271       growOperands();  // Get more space!
   2272     // Initialize some new operands.
   2273     ++NumOperands;
   2274     setIncomingValue(NumOperands - 1, V);
   2275     setIncomingBlock(NumOperands - 1, BB);
   2276   }
   2277 
   2278   /// removeIncomingValue - Remove an incoming value.  This is useful if a
   2279   /// predecessor basic block is deleted.  The value removed is returned.
   2280   ///
   2281   /// If the last incoming value for a PHI node is removed (and DeletePHIIfEmpty
   2282   /// is true), the PHI node is destroyed and any uses of it are replaced with
   2283   /// dummy values.  The only time there should be zero incoming values to a PHI
   2284   /// node is when the block is dead, so this strategy is sound.
   2285   ///
   2286   Value *removeIncomingValue(unsigned Idx, bool DeletePHIIfEmpty = true);
   2287 
   2288   Value *removeIncomingValue(const BasicBlock *BB, bool DeletePHIIfEmpty=true) {
   2289     int Idx = getBasicBlockIndex(BB);
   2290     assert(Idx >= 0 && "Invalid basic block argument to remove!");
   2291     return removeIncomingValue(Idx, DeletePHIIfEmpty);
   2292   }
   2293 
   2294   /// getBasicBlockIndex - Return the first index of the specified basic
   2295   /// block in the value list for this PHI.  Returns -1 if no instance.
   2296   ///
   2297   int getBasicBlockIndex(const BasicBlock *BB) const {
   2298     for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
   2299       if (block_begin()[i] == BB)
   2300         return i;
   2301     return -1;
   2302   }
   2303 
   2304   Value *getIncomingValueForBlock(const BasicBlock *BB) const {
   2305     int Idx = getBasicBlockIndex(BB);
   2306     assert(Idx >= 0 && "Invalid basic block argument!");
   2307     return getIncomingValue(Idx);
   2308   }
   2309 
   2310   /// hasConstantValue - If the specified PHI node always merges together the
   2311   /// same value, return the value, otherwise return null.
   2312   Value *hasConstantValue() const;
   2313 
   2314   /// Methods for support type inquiry through isa, cast, and dyn_cast:
   2315   static inline bool classof(const Instruction *I) {
   2316     return I->getOpcode() == Instruction::PHI;
   2317   }
   2318   static inline bool classof(const Value *V) {
   2319     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   2320   }
   2321  private:
   2322   void growOperands();
   2323 };
   2324 
   2325 template <>
   2326 struct OperandTraits<PHINode> : public HungoffOperandTraits<2> {
   2327 };
   2328 
   2329 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(PHINode, Value)
   2330 
   2331 //===----------------------------------------------------------------------===//
   2332 //                           LandingPadInst Class
   2333 //===----------------------------------------------------------------------===//
   2334 
   2335 //===---------------------------------------------------------------------------
   2336 /// LandingPadInst - The landingpad instruction holds all of the information
   2337 /// necessary to generate correct exception handling. The landingpad instruction
   2338 /// cannot be moved from the top of a landing pad block, which itself is
   2339 /// accessible only from the 'unwind' edge of an invoke. This uses the
   2340 /// SubclassData field in Value to store whether or not the landingpad is a
   2341 /// cleanup.
   2342 ///
   2343 class LandingPadInst : public Instruction {
   2344   /// ReservedSpace - The number of operands actually allocated.  NumOperands is
   2345   /// the number actually in use.
   2346   unsigned ReservedSpace;
   2347   LandingPadInst(const LandingPadInst &LP);
   2348 public:
   2349   enum ClauseType { Catch, Filter };
   2350 private:
   2351   void *operator new(size_t, unsigned) = delete;
   2352   // Allocate space for exactly zero operands.
   2353   void *operator new(size_t s) {
   2354     return User::operator new(s, 0);
   2355   }
   2356   void growOperands(unsigned Size);
   2357   void init(Value *PersFn, unsigned NumReservedValues, const Twine &NameStr);
   2358 
   2359   explicit LandingPadInst(Type *RetTy, Value *PersonalityFn,
   2360                           unsigned NumReservedValues, const Twine &NameStr,
   2361                           Instruction *InsertBefore);
   2362   explicit LandingPadInst(Type *RetTy, Value *PersonalityFn,
   2363                           unsigned NumReservedValues, const Twine &NameStr,
   2364                           BasicBlock *InsertAtEnd);
   2365 protected:
   2366   LandingPadInst *clone_impl() const override;
   2367 public:
   2368   /// Constructors - NumReservedClauses is a hint for the number of incoming
   2369   /// clauses that this landingpad will have (use 0 if you really have no idea).
   2370   static LandingPadInst *Create(Type *RetTy, Value *PersonalityFn,
   2371                                 unsigned NumReservedClauses,
   2372                                 const Twine &NameStr = "",
   2373                                 Instruction *InsertBefore = nullptr);
   2374   static LandingPadInst *Create(Type *RetTy, Value *PersonalityFn,
   2375                                 unsigned NumReservedClauses,
   2376                                 const Twine &NameStr, BasicBlock *InsertAtEnd);
   2377   ~LandingPadInst() override;
   2378 
   2379   /// Provide fast operand accessors
   2380   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
   2381 
   2382   /// getPersonalityFn - Get the personality function associated with this
   2383   /// landing pad.
   2384   Value *getPersonalityFn() const { return getOperand(0); }
   2385 
   2386   /// isCleanup - Return 'true' if this landingpad instruction is a
   2387   /// cleanup. I.e., it should be run when unwinding even if its landing pad
   2388   /// doesn't catch the exception.
   2389   bool isCleanup() const { return getSubclassDataFromInstruction() & 1; }
   2390 
   2391   /// setCleanup - Indicate that this landingpad instruction is a cleanup.
   2392   void setCleanup(bool V) {
   2393     setInstructionSubclassData((getSubclassDataFromInstruction() & ~1) |
   2394                                (V ? 1 : 0));
   2395   }
   2396 
   2397   /// Add a catch or filter clause to the landing pad.
   2398   void addClause(Constant *ClauseVal);
   2399 
   2400   /// Get the value of the clause at index Idx. Use isCatch/isFilter to
   2401   /// determine what type of clause this is.
   2402   Constant *getClause(unsigned Idx) const {
   2403     return cast<Constant>(OperandList[Idx + 1]);
   2404   }
   2405 
   2406   /// isCatch - Return 'true' if the clause and index Idx is a catch clause.
   2407   bool isCatch(unsigned Idx) const {
   2408     return !isa<ArrayType>(OperandList[Idx + 1]->getType());
   2409   }
   2410 
   2411   /// isFilter - Return 'true' if the clause and index Idx is a filter clause.
   2412   bool isFilter(unsigned Idx) const {
   2413     return isa<ArrayType>(OperandList[Idx + 1]->getType());
   2414   }
   2415 
   2416   /// getNumClauses - Get the number of clauses for this landing pad.
   2417   unsigned getNumClauses() const { return getNumOperands() - 1; }
   2418 
   2419   /// reserveClauses - Grow the size of the operand list to accommodate the new
   2420   /// number of clauses.
   2421   void reserveClauses(unsigned Size) { growOperands(Size); }
   2422 
   2423   // Methods for support type inquiry through isa, cast, and dyn_cast:
   2424   static inline bool classof(const Instruction *I) {
   2425     return I->getOpcode() == Instruction::LandingPad;
   2426   }
   2427   static inline bool classof(const Value *V) {
   2428     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   2429   }
   2430 };
   2431 
   2432 template <>
   2433 struct OperandTraits<LandingPadInst> : public HungoffOperandTraits<2> {
   2434 };
   2435 
   2436 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(LandingPadInst, Value)
   2437 
   2438 //===----------------------------------------------------------------------===//
   2439 //                               ReturnInst Class
   2440 //===----------------------------------------------------------------------===//
   2441 
   2442 //===---------------------------------------------------------------------------
   2443 /// ReturnInst - Return a value (possibly void), from a function.  Execution
   2444 /// does not continue in this function any longer.
   2445 ///
   2446 class ReturnInst : public TerminatorInst {
   2447   ReturnInst(const ReturnInst &RI);
   2448 
   2449 private:
   2450   // ReturnInst constructors:
   2451   // ReturnInst()                  - 'ret void' instruction
   2452   // ReturnInst(    null)          - 'ret void' instruction
   2453   // ReturnInst(Value* X)          - 'ret X'    instruction
   2454   // ReturnInst(    null, Inst *I) - 'ret void' instruction, insert before I
   2455   // ReturnInst(Value* X, Inst *I) - 'ret X'    instruction, insert before I
   2456   // ReturnInst(    null, BB *B)   - 'ret void' instruction, insert @ end of B
   2457   // ReturnInst(Value* X, BB *B)   - 'ret X'    instruction, insert @ end of B
   2458   //
   2459   // NOTE: If the Value* passed is of type void then the constructor behaves as
   2460   // if it was passed NULL.
   2461   explicit ReturnInst(LLVMContext &C, Value *retVal = nullptr,
   2462                       Instruction *InsertBefore = nullptr);
   2463   ReturnInst(LLVMContext &C, Value *retVal, BasicBlock *InsertAtEnd);
   2464   explicit ReturnInst(LLVMContext &C, BasicBlock *InsertAtEnd);
   2465 protected:
   2466   ReturnInst *clone_impl() const override;
   2467 public:
   2468   static ReturnInst* Create(LLVMContext &C, Value *retVal = nullptr,
   2469                             Instruction *InsertBefore = nullptr) {
   2470     return new(!!retVal) ReturnInst(C, retVal, InsertBefore);
   2471   }
   2472   static ReturnInst* Create(LLVMContext &C, Value *retVal,
   2473                             BasicBlock *InsertAtEnd) {
   2474     return new(!!retVal) ReturnInst(C, retVal, InsertAtEnd);
   2475   }
   2476   static ReturnInst* Create(LLVMContext &C, BasicBlock *InsertAtEnd) {
   2477     return new(0) ReturnInst(C, InsertAtEnd);
   2478   }
   2479   ~ReturnInst() override;
   2480 
   2481   /// Provide fast operand accessors
   2482   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
   2483 
   2484   /// Convenience accessor. Returns null if there is no return value.
   2485   Value *getReturnValue() const {
   2486     return getNumOperands() != 0 ? getOperand(0) : nullptr;
   2487   }
   2488 
   2489   unsigned getNumSuccessors() const { return 0; }
   2490 
   2491   // Methods for support type inquiry through isa, cast, and dyn_cast:
   2492   static inline bool classof(const Instruction *I) {
   2493     return (I->getOpcode() == Instruction::Ret);
   2494   }
   2495   static inline bool classof(const Value *V) {
   2496     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   2497   }
   2498  private:
   2499   BasicBlock *getSuccessorV(unsigned idx) const override;
   2500   unsigned getNumSuccessorsV() const override;
   2501   void setSuccessorV(unsigned idx, BasicBlock *B) override;
   2502 };
   2503 
   2504 template <>
   2505 struct OperandTraits<ReturnInst> : public VariadicOperandTraits<ReturnInst> {
   2506 };
   2507 
   2508 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ReturnInst, Value)
   2509 
   2510 //===----------------------------------------------------------------------===//
   2511 //                               BranchInst Class
   2512 //===----------------------------------------------------------------------===//
   2513 
   2514 //===---------------------------------------------------------------------------
   2515 /// BranchInst - Conditional or Unconditional Branch instruction.
   2516 ///
   2517 class BranchInst : public TerminatorInst {
   2518   /// Ops list - Branches are strange.  The operands are ordered:
   2519   ///  [Cond, FalseDest,] TrueDest.  This makes some accessors faster because
   2520   /// they don't have to check for cond/uncond branchness. These are mostly
   2521   /// accessed relative from op_end().
   2522   BranchInst(const BranchInst &BI);
   2523   void AssertOK();
   2524   // BranchInst constructors (where {B, T, F} are blocks, and C is a condition):
   2525   // BranchInst(BB *B)                           - 'br B'
   2526   // BranchInst(BB* T, BB *F, Value *C)          - 'br C, T, F'
   2527   // BranchInst(BB* B, Inst *I)                  - 'br B'        insert before I
   2528   // BranchInst(BB* T, BB *F, Value *C, Inst *I) - 'br C, T, F', insert before I
   2529   // BranchInst(BB* B, BB *I)                    - 'br B'        insert at end
   2530   // BranchInst(BB* T, BB *F, Value *C, BB *I)   - 'br C, T, F', insert at end
   2531   explicit BranchInst(BasicBlock *IfTrue, Instruction *InsertBefore = nullptr);
   2532   BranchInst(BasicBlock *IfTrue, BasicBlock *IfFalse, Value *Cond,
   2533              Instruction *InsertBefore = nullptr);
   2534   BranchInst(BasicBlock *IfTrue, BasicBlock *InsertAtEnd);
   2535   BranchInst(BasicBlock *IfTrue, BasicBlock *IfFalse, Value *Cond,
   2536              BasicBlock *InsertAtEnd);
   2537 protected:
   2538   BranchInst *clone_impl() const override;
   2539 public:
   2540   static BranchInst *Create(BasicBlock *IfTrue,
   2541                             Instruction *InsertBefore = nullptr) {
   2542     return new(1) BranchInst(IfTrue, InsertBefore);
   2543   }
   2544   static BranchInst *Create(BasicBlock *IfTrue, BasicBlock *IfFalse,
   2545                             Value *Cond, Instruction *InsertBefore = nullptr) {
   2546     return new(3) BranchInst(IfTrue, IfFalse, Cond, InsertBefore);
   2547   }
   2548   static BranchInst *Create(BasicBlock *IfTrue, BasicBlock *InsertAtEnd) {
   2549     return new(1) BranchInst(IfTrue, InsertAtEnd);
   2550   }
   2551   static BranchInst *Create(BasicBlock *IfTrue, BasicBlock *IfFalse,
   2552                             Value *Cond, BasicBlock *InsertAtEnd) {
   2553     return new(3) BranchInst(IfTrue, IfFalse, Cond, InsertAtEnd);
   2554   }
   2555 
   2556   /// Transparently provide more efficient getOperand methods.
   2557   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
   2558 
   2559   bool isUnconditional() const { return getNumOperands() == 1; }
   2560   bool isConditional()   const { return getNumOperands() == 3; }
   2561 
   2562   Value *getCondition() const {
   2563     assert(isConditional() && "Cannot get condition of an uncond branch!");
   2564     return Op<-3>();
   2565   }
   2566 
   2567   void setCondition(Value *V) {
   2568     assert(isConditional() && "Cannot set condition of unconditional branch!");
   2569     Op<-3>() = V;
   2570   }
   2571 
   2572   unsigned getNumSuccessors() const { return 1+isConditional(); }
   2573 
   2574   BasicBlock *getSuccessor(unsigned i) const {
   2575     assert(i < getNumSuccessors() && "Successor # out of range for Branch!");
   2576     return cast_or_null<BasicBlock>((&Op<-1>() - i)->get());
   2577   }
   2578 
   2579   void setSuccessor(unsigned idx, BasicBlock *NewSucc) {
   2580     assert(idx < getNumSuccessors() && "Successor # out of range for Branch!");
   2581     *(&Op<-1>() - idx) = (Value*)NewSucc;
   2582   }
   2583 
   2584   /// \brief Swap the successors of this branch instruction.
   2585   ///
   2586   /// Swaps the successors of the branch instruction. This also swaps any
   2587   /// branch weight metadata associated with the instruction so that it
   2588   /// continues to map correctly to each operand.
   2589   void swapSuccessors();
   2590 
   2591   // Methods for support type inquiry through isa, cast, and dyn_cast:
   2592   static inline bool classof(const Instruction *I) {
   2593     return (I->getOpcode() == Instruction::Br);
   2594   }
   2595   static inline bool classof(const Value *V) {
   2596     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   2597   }
   2598 private:
   2599   BasicBlock *getSuccessorV(unsigned idx) const override;
   2600   unsigned getNumSuccessorsV() const override;
   2601   void setSuccessorV(unsigned idx, BasicBlock *B) override;
   2602 };
   2603 
   2604 template <>
   2605 struct OperandTraits<BranchInst> : public VariadicOperandTraits<BranchInst, 1> {
   2606 };
   2607 
   2608 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(BranchInst, Value)
   2609 
   2610 //===----------------------------------------------------------------------===//
   2611 //                               SwitchInst Class
   2612 //===----------------------------------------------------------------------===//
   2613 
   2614 //===---------------------------------------------------------------------------
   2615 /// SwitchInst - Multiway switch
   2616 ///
   2617 class SwitchInst : public TerminatorInst {
   2618   void *operator new(size_t, unsigned) = delete;
   2619   unsigned ReservedSpace;
   2620   // Operand[0]    = Value to switch on
   2621   // Operand[1]    = Default basic block destination
   2622   // Operand[2n  ] = Value to match
   2623   // Operand[2n+1] = BasicBlock to go to on match
   2624   SwitchInst(const SwitchInst &SI);
   2625   void init(Value *Value, BasicBlock *Default, unsigned NumReserved);
   2626   void growOperands();
   2627   // allocate space for exactly zero operands
   2628   void *operator new(size_t s) {
   2629     return User::operator new(s, 0);
   2630   }
   2631   /// SwitchInst ctor - Create a new switch instruction, specifying a value to
   2632   /// switch on and a default destination.  The number of additional cases can
   2633   /// be specified here to make memory allocation more efficient.  This
   2634   /// constructor can also autoinsert before another instruction.
   2635   SwitchInst(Value *Value, BasicBlock *Default, unsigned NumCases,
   2636              Instruction *InsertBefore);
   2637 
   2638   /// SwitchInst ctor - Create a new switch instruction, specifying a value to
   2639   /// switch on and a default destination.  The number of additional cases can
   2640   /// be specified here to make memory allocation more efficient.  This
   2641   /// constructor also autoinserts at the end of the specified BasicBlock.
   2642   SwitchInst(Value *Value, BasicBlock *Default, unsigned NumCases,
   2643              BasicBlock *InsertAtEnd);
   2644 protected:
   2645   SwitchInst *clone_impl() const override;
   2646 public:
   2647 
   2648   // -2
   2649   static const unsigned DefaultPseudoIndex = static_cast<unsigned>(~0L-1);
   2650 
   2651   template <class SwitchInstTy, class ConstantIntTy, class BasicBlockTy>
   2652   class CaseIteratorT {
   2653   protected:
   2654 
   2655     SwitchInstTy *SI;
   2656     unsigned Index;
   2657 
   2658   public:
   2659 
   2660     typedef CaseIteratorT<SwitchInstTy, ConstantIntTy, BasicBlockTy> Self;
   2661 
   2662     /// Initializes case iterator for given SwitchInst and for given
   2663     /// case number.
   2664     CaseIteratorT(SwitchInstTy *SI, unsigned CaseNum) {
   2665       this->SI = SI;
   2666       Index = CaseNum;
   2667     }
   2668 
   2669     /// Initializes case iterator for given SwitchInst and for given
   2670     /// TerminatorInst's successor index.
   2671     static Self fromSuccessorIndex(SwitchInstTy *SI, unsigned SuccessorIndex) {
   2672       assert(SuccessorIndex < SI->getNumSuccessors() &&
   2673              "Successor index # out of range!");
   2674       return SuccessorIndex != 0 ?
   2675              Self(SI, SuccessorIndex - 1) :
   2676              Self(SI, DefaultPseudoIndex);
   2677     }
   2678 
   2679     /// Resolves case value for current case.
   2680     ConstantIntTy *getCaseValue() {
   2681       assert(Index < SI->getNumCases() && "Index out the number of cases.");
   2682       return reinterpret_cast<ConstantIntTy*>(SI->getOperand(2 + Index*2));
   2683     }
   2684 
   2685     /// Resolves successor for current case.
   2686     BasicBlockTy *getCaseSuccessor() {
   2687       assert((Index < SI->getNumCases() ||
   2688               Index == DefaultPseudoIndex) &&
   2689              "Index out the number of cases.");
   2690       return SI->getSuccessor(getSuccessorIndex());
   2691     }
   2692 
   2693     /// Returns number of current case.
   2694     unsigned getCaseIndex() const { return Index; }
   2695 
   2696     /// Returns TerminatorInst's successor index for current case successor.
   2697     unsigned getSuccessorIndex() const {
   2698       assert((Index == DefaultPseudoIndex || Index < SI->getNumCases()) &&
   2699              "Index out the number of cases.");
   2700       return Index != DefaultPseudoIndex ? Index + 1 : 0;
   2701     }
   2702 
   2703     Self operator++() {
   2704       // Check index correctness after increment.
   2705       // Note: Index == getNumCases() means end().
   2706       assert(Index+1 <= SI->getNumCases() && "Index out the number of cases.");
   2707       ++Index;
   2708       return *this;
   2709     }
   2710     Self operator++(int) {
   2711       Self tmp = *this;
   2712       ++(*this);
   2713       return tmp;
   2714     }
   2715     Self operator--() {
   2716       // Check index correctness after decrement.
   2717       // Note: Index == getNumCases() means end().
   2718       // Also allow "-1" iterator here. That will became valid after ++.
   2719       assert((Index == 0 || Index-1 <= SI->getNumCases()) &&
   2720              "Index out the number of cases.");
   2721       --Index;
   2722       return *this;
   2723     }
   2724     Self operator--(int) {
   2725       Self tmp = *this;
   2726       --(*this);
   2727       return tmp;
   2728     }
   2729     bool operator==(const Self& RHS) const {
   2730       assert(RHS.SI == SI && "Incompatible operators.");
   2731       return RHS.Index == Index;
   2732     }
   2733     bool operator!=(const Self& RHS) const {
   2734       assert(RHS.SI == SI && "Incompatible operators.");
   2735       return RHS.Index != Index;
   2736     }
   2737     Self &operator*() {
   2738       return *this;
   2739     }
   2740   };
   2741 
   2742   typedef CaseIteratorT<const SwitchInst, const ConstantInt, const BasicBlock>
   2743     ConstCaseIt;
   2744 
   2745   class CaseIt : public CaseIteratorT<SwitchInst, ConstantInt, BasicBlock> {
   2746 
   2747     typedef CaseIteratorT<SwitchInst, ConstantInt, BasicBlock> ParentTy;
   2748 
   2749   public:
   2750 
   2751     CaseIt(const ParentTy& Src) : ParentTy(Src) {}
   2752     CaseIt(SwitchInst *SI, unsigned CaseNum) : ParentTy(SI, CaseNum) {}
   2753 
   2754     /// Sets the new value for current case.
   2755     void setValue(ConstantInt *V) {
   2756       assert(Index < SI->getNumCases() && "Index out the number of cases.");
   2757       SI->setOperand(2 + Index*2, reinterpret_cast<Value*>(V));
   2758     }
   2759 
   2760     /// Sets the new successor for current case.
   2761     void setSuccessor(BasicBlock *S) {
   2762       SI->setSuccessor(getSuccessorIndex(), S);
   2763     }
   2764   };
   2765 
   2766   static SwitchInst *Create(Value *Value, BasicBlock *Default,
   2767                             unsigned NumCases,
   2768                             Instruction *InsertBefore = nullptr) {
   2769     return new SwitchInst(Value, Default, NumCases, InsertBefore);
   2770   }
   2771   static SwitchInst *Create(Value *Value, BasicBlock *Default,
   2772                             unsigned NumCases, BasicBlock *InsertAtEnd) {
   2773     return new SwitchInst(Value, Default, NumCases, InsertAtEnd);
   2774   }
   2775 
   2776   ~SwitchInst() override;
   2777 
   2778   /// Provide fast operand accessors
   2779   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
   2780 
   2781   // Accessor Methods for Switch stmt
   2782   Value *getCondition() const { return getOperand(0); }
   2783   void setCondition(Value *V) { setOperand(0, V); }
   2784 
   2785   BasicBlock *getDefaultDest() const {
   2786     return cast<BasicBlock>(getOperand(1));
   2787   }
   2788 
   2789   void setDefaultDest(BasicBlock *DefaultCase) {
   2790     setOperand(1, reinterpret_cast<Value*>(DefaultCase));
   2791   }
   2792 
   2793   /// getNumCases - return the number of 'cases' in this switch instruction,
   2794   /// except the default case
   2795   unsigned getNumCases() const {
   2796     return getNumOperands()/2 - 1;
   2797   }
   2798 
   2799   /// Returns a read/write iterator that points to the first
   2800   /// case in SwitchInst.
   2801   CaseIt case_begin() {
   2802     return CaseIt(this, 0);
   2803   }
   2804   /// Returns a read-only iterator that points to the first
   2805   /// case in the SwitchInst.
   2806   ConstCaseIt case_begin() const {
   2807     return ConstCaseIt(this, 0);
   2808   }
   2809 
   2810   /// Returns a read/write iterator that points one past the last
   2811   /// in the SwitchInst.
   2812   CaseIt case_end() {
   2813     return CaseIt(this, getNumCases());
   2814   }
   2815   /// Returns a read-only iterator that points one past the last
   2816   /// in the SwitchInst.
   2817   ConstCaseIt case_end() const {
   2818     return ConstCaseIt(this, getNumCases());
   2819   }
   2820 
   2821   /// cases - iteration adapter for range-for loops.
   2822   iterator_range<CaseIt> cases() {
   2823     return iterator_range<CaseIt>(case_begin(), case_end());
   2824   }
   2825 
   2826   /// cases - iteration adapter for range-for loops.
   2827   iterator_range<ConstCaseIt> cases() const {
   2828     return iterator_range<ConstCaseIt>(case_begin(), case_end());
   2829   }
   2830 
   2831   /// Returns an iterator that points to the default case.
   2832   /// Note: this iterator allows to resolve successor only. Attempt
   2833   /// to resolve case value causes an assertion.
   2834   /// Also note, that increment and decrement also causes an assertion and
   2835   /// makes iterator invalid.
   2836   CaseIt case_default() {
   2837     return CaseIt(this, DefaultPseudoIndex);
   2838   }
   2839   ConstCaseIt case_default() const {
   2840     return ConstCaseIt(this, DefaultPseudoIndex);
   2841   }
   2842 
   2843   /// findCaseValue - Search all of the case values for the specified constant.
   2844   /// If it is explicitly handled, return the case iterator of it, otherwise
   2845   /// return default case iterator to indicate
   2846   /// that it is handled by the default handler.
   2847   CaseIt findCaseValue(const ConstantInt *C) {
   2848     for (CaseIt i = case_begin(), e = case_end(); i != e; ++i)
   2849       if (i.getCaseValue() == C)
   2850         return i;
   2851     return case_default();
   2852   }
   2853   ConstCaseIt findCaseValue(const ConstantInt *C) const {
   2854     for (ConstCaseIt i = case_begin(), e = case_end(); i != e; ++i)
   2855       if (i.getCaseValue() == C)
   2856         return i;
   2857     return case_default();
   2858   }
   2859 
   2860   /// findCaseDest - Finds the unique case value for a given successor. Returns
   2861   /// null if the successor is not found, not unique, or is the default case.
   2862   ConstantInt *findCaseDest(BasicBlock *BB) {
   2863     if (BB == getDefaultDest()) return nullptr;
   2864 
   2865     ConstantInt *CI = nullptr;
   2866     for (CaseIt i = case_begin(), e = case_end(); i != e; ++i) {
   2867       if (i.getCaseSuccessor() == BB) {
   2868         if (CI) return nullptr;   // Multiple cases lead to BB.
   2869         else CI = i.getCaseValue();
   2870       }
   2871     }
   2872     return CI;
   2873   }
   2874 
   2875   /// addCase - Add an entry to the switch instruction...
   2876   /// Note:
   2877   /// This action invalidates case_end(). Old case_end() iterator will
   2878   /// point to the added case.
   2879   void addCase(ConstantInt *OnVal, BasicBlock *Dest);
   2880 
   2881   /// removeCase - This method removes the specified case and its successor
   2882   /// from the switch instruction. Note that this operation may reorder the
   2883   /// remaining cases at index idx and above.
   2884   /// Note:
   2885   /// This action invalidates iterators for all cases following the one removed,
   2886   /// including the case_end() iterator.
   2887   void removeCase(CaseIt i);
   2888 
   2889   unsigned getNumSuccessors() const { return getNumOperands()/2; }
   2890   BasicBlock *getSuccessor(unsigned idx) const {
   2891     assert(idx < getNumSuccessors() &&"Successor idx out of range for switch!");
   2892     return cast<BasicBlock>(getOperand(idx*2+1));
   2893   }
   2894   void setSuccessor(unsigned idx, BasicBlock *NewSucc) {
   2895     assert(idx < getNumSuccessors() && "Successor # out of range for switch!");
   2896     setOperand(idx*2+1, (Value*)NewSucc);
   2897   }
   2898 
   2899   // Methods for support type inquiry through isa, cast, and dyn_cast:
   2900   static inline bool classof(const Instruction *I) {
   2901     return I->getOpcode() == Instruction::Switch;
   2902   }
   2903   static inline bool classof(const Value *V) {
   2904     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   2905   }
   2906 private:
   2907   BasicBlock *getSuccessorV(unsigned idx) const override;
   2908   unsigned getNumSuccessorsV() const override;
   2909   void setSuccessorV(unsigned idx, BasicBlock *B) override;
   2910 };
   2911 
   2912 template <>
   2913 struct OperandTraits<SwitchInst> : public HungoffOperandTraits<2> {
   2914 };
   2915 
   2916 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(SwitchInst, Value)
   2917 
   2918 
   2919 //===----------------------------------------------------------------------===//
   2920 //                             IndirectBrInst Class
   2921 //===----------------------------------------------------------------------===//
   2922 
   2923 //===---------------------------------------------------------------------------
   2924 /// IndirectBrInst - Indirect Branch Instruction.
   2925 ///
   2926 class IndirectBrInst : public TerminatorInst {
   2927   void *operator new(size_t, unsigned) = delete;
   2928   unsigned ReservedSpace;
   2929   // Operand[0]    = Value to switch on
   2930   // Operand[1]    = Default basic block destination
   2931   // Operand[2n  ] = Value to match
   2932   // Operand[2n+1] = BasicBlock to go to on match
   2933   IndirectBrInst(const IndirectBrInst &IBI);
   2934   void init(Value *Address, unsigned NumDests);
   2935   void growOperands();
   2936   // allocate space for exactly zero operands
   2937   void *operator new(size_t s) {
   2938     return User::operator new(s, 0);
   2939   }
   2940   /// IndirectBrInst ctor - Create a new indirectbr instruction, specifying an
   2941   /// Address to jump to.  The number of expected destinations can be specified
   2942   /// here to make memory allocation more efficient.  This constructor can also
   2943   /// autoinsert before another instruction.
   2944   IndirectBrInst(Value *Address, unsigned NumDests, Instruction *InsertBefore);
   2945 
   2946   /// IndirectBrInst ctor - Create a new indirectbr instruction, specifying an
   2947   /// Address to jump to.  The number of expected destinations can be specified
   2948   /// here to make memory allocation more efficient.  This constructor also
   2949   /// autoinserts at the end of the specified BasicBlock.
   2950   IndirectBrInst(Value *Address, unsigned NumDests, BasicBlock *InsertAtEnd);
   2951 protected:
   2952   IndirectBrInst *clone_impl() const override;
   2953 public:
   2954   static IndirectBrInst *Create(Value *Address, unsigned NumDests,
   2955                                 Instruction *InsertBefore = nullptr) {
   2956     return new IndirectBrInst(Address, NumDests, InsertBefore);
   2957   }
   2958   static IndirectBrInst *Create(Value *Address, unsigned NumDests,
   2959                                 BasicBlock *InsertAtEnd) {
   2960     return new IndirectBrInst(Address, NumDests, InsertAtEnd);
   2961   }
   2962   ~IndirectBrInst() override;
   2963 
   2964   /// Provide fast operand accessors.
   2965   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
   2966 
   2967   // Accessor Methods for IndirectBrInst instruction.
   2968   Value *getAddress() { return getOperand(0); }
   2969   const Value *getAddress() const { return getOperand(0); }
   2970   void setAddress(Value *V) { setOperand(0, V); }
   2971 
   2972 
   2973   /// getNumDestinations - return the number of possible destinations in this
   2974   /// indirectbr instruction.
   2975   unsigned getNumDestinations() const { return getNumOperands()-1; }
   2976 
   2977   /// getDestination - Return the specified destination.
   2978   BasicBlock *getDestination(unsigned i) { return getSuccessor(i); }
   2979   const BasicBlock *getDestination(unsigned i) const { return getSuccessor(i); }
   2980 
   2981   /// addDestination - Add a destination.
   2982   ///
   2983   void addDestination(BasicBlock *Dest);
   2984 
   2985   /// removeDestination - This method removes the specified successor from the
   2986   /// indirectbr instruction.
   2987   void removeDestination(unsigned i);
   2988 
   2989   unsigned getNumSuccessors() const { return getNumOperands()-1; }
   2990   BasicBlock *getSuccessor(unsigned i) const {
   2991     return cast<BasicBlock>(getOperand(i+1));
   2992   }
   2993   void setSuccessor(unsigned i, BasicBlock *NewSucc) {
   2994     setOperand(i+1, (Value*)NewSucc);
   2995   }
   2996 
   2997   // Methods for support type inquiry through isa, cast, and dyn_cast:
   2998   static inline bool classof(const Instruction *I) {
   2999     return I->getOpcode() == Instruction::IndirectBr;
   3000   }
   3001   static inline bool classof(const Value *V) {
   3002     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   3003   }
   3004 private:
   3005   BasicBlock *getSuccessorV(unsigned idx) const override;
   3006   unsigned getNumSuccessorsV() const override;
   3007   void setSuccessorV(unsigned idx, BasicBlock *B) override;
   3008 };
   3009 
   3010 template <>
   3011 struct OperandTraits<IndirectBrInst> : public HungoffOperandTraits<1> {
   3012 };
   3013 
   3014 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(IndirectBrInst, Value)
   3015 
   3016 
   3017 //===----------------------------------------------------------------------===//
   3018 //                               InvokeInst Class
   3019 //===----------------------------------------------------------------------===//
   3020 
   3021 /// InvokeInst - Invoke instruction.  The SubclassData field is used to hold the
   3022 /// calling convention of the call.
   3023 ///
   3024 class InvokeInst : public TerminatorInst {
   3025   AttributeSet AttributeList;
   3026   InvokeInst(const InvokeInst &BI);
   3027   void init(Value *Func, BasicBlock *IfNormal, BasicBlock *IfException,
   3028             ArrayRef<Value *> Args, const Twine &NameStr);
   3029 
   3030   /// Construct an InvokeInst given a range of arguments.
   3031   ///
   3032   /// \brief Construct an InvokeInst from a range of arguments
   3033   inline InvokeInst(Value *Func, BasicBlock *IfNormal, BasicBlock *IfException,
   3034                     ArrayRef<Value *> Args, unsigned Values,
   3035                     const Twine &NameStr, Instruction *InsertBefore);
   3036 
   3037   /// Construct an InvokeInst given a range of arguments.
   3038   ///
   3039   /// \brief Construct an InvokeInst from a range of arguments
   3040   inline InvokeInst(Value *Func, BasicBlock *IfNormal, BasicBlock *IfException,
   3041                     ArrayRef<Value *> Args, unsigned Values,
   3042                     const Twine &NameStr, BasicBlock *InsertAtEnd);
   3043 protected:
   3044   InvokeInst *clone_impl() const override;
   3045 public:
   3046   static InvokeInst *Create(Value *Func,
   3047                             BasicBlock *IfNormal, BasicBlock *IfException,
   3048                             ArrayRef<Value *> Args, const Twine &NameStr = "",
   3049                             Instruction *InsertBefore = nullptr) {
   3050     unsigned Values = unsigned(Args.size()) + 3;
   3051     return new(Values) InvokeInst(Func, IfNormal, IfException, Args,
   3052                                   Values, NameStr, InsertBefore);
   3053   }
   3054   static InvokeInst *Create(Value *Func,
   3055                             BasicBlock *IfNormal, BasicBlock *IfException,
   3056                             ArrayRef<Value *> Args, const Twine &NameStr,
   3057                             BasicBlock *InsertAtEnd) {
   3058     unsigned Values = unsigned(Args.size()) + 3;
   3059     return new(Values) InvokeInst(Func, IfNormal, IfException, Args,
   3060                                   Values, NameStr, InsertAtEnd);
   3061   }
   3062 
   3063   /// Provide fast operand accessors
   3064   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
   3065 
   3066   /// getNumArgOperands - Return the number of invoke arguments.
   3067   ///
   3068   unsigned getNumArgOperands() const { return getNumOperands() - 3; }
   3069 
   3070   /// getArgOperand/setArgOperand - Return/set the i-th invoke argument.
   3071   ///
   3072   Value *getArgOperand(unsigned i) const { return getOperand(i); }
   3073   void setArgOperand(unsigned i, Value *v) { setOperand(i, v); }
   3074 
   3075   /// arg_operands - iteration adapter for range-for loops.
   3076   iterator_range<op_iterator> arg_operands() {
   3077     return iterator_range<op_iterator>(op_begin(), op_end() - 3);
   3078   }
   3079 
   3080   /// arg_operands - iteration adapter for range-for loops.
   3081   iterator_range<const_op_iterator> arg_operands() const {
   3082     return iterator_range<const_op_iterator>(op_begin(), op_end() - 3);
   3083   }
   3084 
   3085   /// \brief Wrappers for getting the \c Use of a invoke argument.
   3086   const Use &getArgOperandUse(unsigned i) const { return getOperandUse(i); }
   3087   Use &getArgOperandUse(unsigned i) { return getOperandUse(i); }
   3088 
   3089   /// getCallingConv/setCallingConv - Get or set the calling convention of this
   3090   /// function call.
   3091   CallingConv::ID getCallingConv() const {
   3092     return static_cast<CallingConv::ID>(getSubclassDataFromInstruction());
   3093   }
   3094   void setCallingConv(CallingConv::ID CC) {
   3095     setInstructionSubclassData(static_cast<unsigned>(CC));
   3096   }
   3097 
   3098   /// getAttributes - Return the parameter attributes for this invoke.
   3099   ///
   3100   const AttributeSet &getAttributes() const { return AttributeList; }
   3101 
   3102   /// setAttributes - Set the parameter attributes for this invoke.
   3103   ///
   3104   void setAttributes(const AttributeSet &Attrs) { AttributeList = Attrs; }
   3105 
   3106   /// addAttribute - adds the attribute to the list of attributes.
   3107   void addAttribute(unsigned i, Attribute::AttrKind attr);
   3108 
   3109   /// removeAttribute - removes the attribute from the list of attributes.
   3110   void removeAttribute(unsigned i, Attribute attr);
   3111 
   3112   /// \brief adds the dereferenceable attribute to the list of attributes.
   3113   void addDereferenceableAttr(unsigned i, uint64_t Bytes);
   3114 
   3115   /// \brief adds the dereferenceable_or_null attribute to the list of
   3116   /// attributes.
   3117   void addDereferenceableOrNullAttr(unsigned i, uint64_t Bytes);
   3118 
   3119   /// \brief Determine whether this call has the given attribute.
   3120   bool hasFnAttr(Attribute::AttrKind A) const {
   3121     assert(A != Attribute::NoBuiltin &&
   3122            "Use CallInst::isNoBuiltin() to check for Attribute::NoBuiltin");
   3123     return hasFnAttrImpl(A);
   3124   }
   3125 
   3126   /// \brief Determine whether the call or the callee has the given attributes.
   3127   bool paramHasAttr(unsigned i, Attribute::AttrKind A) const;
   3128 
   3129   /// \brief Extract the alignment for a call or parameter (0=unknown).
   3130   unsigned getParamAlignment(unsigned i) const {
   3131     return AttributeList.getParamAlignment(i);
   3132   }
   3133 
   3134   /// \brief Extract the number of dereferenceable bytes for a call or
   3135   /// parameter (0=unknown).
   3136   uint64_t getDereferenceableBytes(unsigned i) const {
   3137     return AttributeList.getDereferenceableBytes(i);
   3138   }
   3139 
   3140   /// \brief Return true if the call should not be treated as a call to a
   3141   /// builtin.
   3142   bool isNoBuiltin() const {
   3143     // We assert in hasFnAttr if one passes in Attribute::NoBuiltin, so we have
   3144     // to check it by hand.
   3145     return hasFnAttrImpl(Attribute::NoBuiltin) &&
   3146       !hasFnAttrImpl(Attribute::Builtin);
   3147   }
   3148 
   3149   /// \brief Return true if the call should not be inlined.
   3150   bool isNoInline() const { return hasFnAttr(Attribute::NoInline); }
   3151   void setIsNoInline() {
   3152     addAttribute(AttributeSet::FunctionIndex, Attribute::NoInline);
   3153   }
   3154 
   3155   /// \brief Determine if the call does not access memory.
   3156   bool doesNotAccessMemory() const {
   3157     return hasFnAttr(Attribute::ReadNone);
   3158   }
   3159   void setDoesNotAccessMemory() {
   3160     addAttribute(AttributeSet::FunctionIndex, Attribute::ReadNone);
   3161   }
   3162 
   3163   /// \brief Determine if the call does not access or only reads memory.
   3164   bool onlyReadsMemory() const {
   3165     return doesNotAccessMemory() || hasFnAttr(Attribute::ReadOnly);
   3166   }
   3167   void setOnlyReadsMemory() {
   3168     addAttribute(AttributeSet::FunctionIndex, Attribute::ReadOnly);
   3169   }
   3170 
   3171   /// \brief Determine if the call cannot return.
   3172   bool doesNotReturn() const { return hasFnAttr(Attribute::NoReturn); }
   3173   void setDoesNotReturn() {
   3174     addAttribute(AttributeSet::FunctionIndex, Attribute::NoReturn);
   3175   }
   3176 
   3177   /// \brief Determine if the call cannot unwind.
   3178   bool doesNotThrow() const { return hasFnAttr(Attribute::NoUnwind); }
   3179   void setDoesNotThrow() {
   3180     addAttribute(AttributeSet::FunctionIndex, Attribute::NoUnwind);
   3181   }
   3182 
   3183   /// \brief Determine if the invoke cannot be duplicated.
   3184   bool cannotDuplicate() const {return hasFnAttr(Attribute::NoDuplicate); }
   3185   void setCannotDuplicate() {
   3186     addAttribute(AttributeSet::FunctionIndex, Attribute::NoDuplicate);
   3187   }
   3188 
   3189   /// \brief Determine if the call returns a structure through first
   3190   /// pointer argument.
   3191   bool hasStructRetAttr() const {
   3192     // Be friendly and also check the callee.
   3193     return paramHasAttr(1, Attribute::StructRet);
   3194   }
   3195 
   3196   /// \brief Determine if any call argument is an aggregate passed by value.
   3197   bool hasByValArgument() const {
   3198     return AttributeList.hasAttrSomewhere(Attribute::ByVal);
   3199   }
   3200 
   3201   /// getCalledFunction - Return the function called, or null if this is an
   3202   /// indirect function invocation.
   3203   ///
   3204   Function *getCalledFunction() const {
   3205     return dyn_cast<Function>(Op<-3>());
   3206   }
   3207 
   3208   /// getCalledValue - Get a pointer to the function that is invoked by this
   3209   /// instruction
   3210   const Value *getCalledValue() const { return Op<-3>(); }
   3211         Value *getCalledValue()       { return Op<-3>(); }
   3212 
   3213   /// setCalledFunction - Set the function called.
   3214   void setCalledFunction(Value* Fn) {
   3215     Op<-3>() = Fn;
   3216   }
   3217 
   3218   // get*Dest - Return the destination basic blocks...
   3219   BasicBlock *getNormalDest() const {
   3220     return cast<BasicBlock>(Op<-2>());
   3221   }
   3222   BasicBlock *getUnwindDest() const {
   3223     return cast<BasicBlock>(Op<-1>());
   3224   }
   3225   void setNormalDest(BasicBlock *B) {
   3226     Op<-2>() = reinterpret_cast<Value*>(B);
   3227   }
   3228   void setUnwindDest(BasicBlock *B) {
   3229     Op<-1>() = reinterpret_cast<Value*>(B);
   3230   }
   3231 
   3232   /// getLandingPadInst - Get the landingpad instruction from the landing pad
   3233   /// block (the unwind destination).
   3234   LandingPadInst *getLandingPadInst() const;
   3235 
   3236   BasicBlock *getSuccessor(unsigned i) const {
   3237     assert(i < 2 && "Successor # out of range for invoke!");
   3238     return i == 0 ? getNormalDest() : getUnwindDest();
   3239   }
   3240 
   3241   void setSuccessor(unsigned idx, BasicBlock *NewSucc) {
   3242     assert(idx < 2 && "Successor # out of range for invoke!");
   3243     *(&Op<-2>() + idx) = reinterpret_cast<Value*>(NewSucc);
   3244   }
   3245 
   3246   unsigned getNumSuccessors() const { return 2; }
   3247 
   3248   // Methods for support type inquiry through isa, cast, and dyn_cast:
   3249   static inline bool classof(const Instruction *I) {
   3250     return (I->getOpcode() == Instruction::Invoke);
   3251   }
   3252   static inline bool classof(const Value *V) {
   3253     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   3254   }
   3255 
   3256 private:
   3257   BasicBlock *getSuccessorV(unsigned idx) const override;
   3258   unsigned getNumSuccessorsV() const override;
   3259   void setSuccessorV(unsigned idx, BasicBlock *B) override;
   3260 
   3261   bool hasFnAttrImpl(Attribute::AttrKind A) const;
   3262 
   3263   // Shadow Instruction::setInstructionSubclassData with a private forwarding
   3264   // method so that subclasses cannot accidentally use it.
   3265   void setInstructionSubclassData(unsigned short D) {
   3266     Instruction::setInstructionSubclassData(D);
   3267   }
   3268 };
   3269 
   3270 template <>
   3271 struct OperandTraits<InvokeInst> : public VariadicOperandTraits<InvokeInst, 3> {
   3272 };
   3273 
   3274 InvokeInst::InvokeInst(Value *Func,
   3275                        BasicBlock *IfNormal, BasicBlock *IfException,
   3276                        ArrayRef<Value *> Args, unsigned Values,
   3277                        const Twine &NameStr, Instruction *InsertBefore)
   3278   : TerminatorInst(cast<FunctionType>(cast<PointerType>(Func->getType())
   3279                                       ->getElementType())->getReturnType(),
   3280                    Instruction::Invoke,
   3281                    OperandTraits<InvokeInst>::op_end(this) - Values,
   3282                    Values, InsertBefore) {
   3283   init(Func, IfNormal, IfException, Args, NameStr);
   3284 }
   3285 InvokeInst::InvokeInst(Value *Func,
   3286                        BasicBlock *IfNormal, BasicBlock *IfException,
   3287                        ArrayRef<Value *> Args, unsigned Values,
   3288                        const Twine &NameStr, BasicBlock *InsertAtEnd)
   3289   : TerminatorInst(cast<FunctionType>(cast<PointerType>(Func->getType())
   3290                                       ->getElementType())->getReturnType(),
   3291                    Instruction::Invoke,
   3292                    OperandTraits<InvokeInst>::op_end(this) - Values,
   3293                    Values, InsertAtEnd) {
   3294   init(Func, IfNormal, IfException, Args, NameStr);
   3295 }
   3296 
   3297 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(InvokeInst, Value)
   3298 
   3299 //===----------------------------------------------------------------------===//
   3300 //                              ResumeInst Class
   3301 //===----------------------------------------------------------------------===//
   3302 
   3303 //===---------------------------------------------------------------------------
   3304 /// ResumeInst - Resume the propagation of an exception.
   3305 ///
   3306 class ResumeInst : public TerminatorInst {
   3307   ResumeInst(const ResumeInst &RI);
   3308 
   3309   explicit ResumeInst(Value *Exn, Instruction *InsertBefore=nullptr);
   3310   ResumeInst(Value *Exn, BasicBlock *InsertAtEnd);
   3311 protected:
   3312   ResumeInst *clone_impl() const override;
   3313 public:
   3314   static ResumeInst *Create(Value *Exn, Instruction *InsertBefore = nullptr) {
   3315     return new(1) ResumeInst(Exn, InsertBefore);
   3316   }
   3317   static ResumeInst *Create(Value *Exn, BasicBlock *InsertAtEnd) {
   3318     return new(1) ResumeInst(Exn, InsertAtEnd);
   3319   }
   3320 
   3321   /// Provide fast operand accessors
   3322   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
   3323 
   3324   /// Convenience accessor.
   3325   Value *getValue() const { return Op<0>(); }
   3326 
   3327   unsigned getNumSuccessors() const { return 0; }
   3328 
   3329   // Methods for support type inquiry through isa, cast, and dyn_cast:
   3330   static inline bool classof(const Instruction *I) {
   3331     return I->getOpcode() == Instruction::Resume;
   3332   }
   3333   static inline bool classof(const Value *V) {
   3334     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   3335   }
   3336 private:
   3337   BasicBlock *getSuccessorV(unsigned idx) const override;
   3338   unsigned getNumSuccessorsV() const override;
   3339   void setSuccessorV(unsigned idx, BasicBlock *B) override;
   3340 };
   3341 
   3342 template <>
   3343 struct OperandTraits<ResumeInst> :
   3344     public FixedNumOperandTraits<ResumeInst, 1> {
   3345 };
   3346 
   3347 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ResumeInst, Value)
   3348 
   3349 //===----------------------------------------------------------------------===//
   3350 //                           UnreachableInst Class
   3351 //===----------------------------------------------------------------------===//
   3352 
   3353 //===---------------------------------------------------------------------------
   3354 /// UnreachableInst - This function has undefined behavior.  In particular, the
   3355 /// presence of this instruction indicates some higher level knowledge that the
   3356 /// end of the block cannot be reached.
   3357 ///
   3358 class UnreachableInst : public TerminatorInst {
   3359   void *operator new(size_t, unsigned) = delete;
   3360 protected:
   3361   UnreachableInst *clone_impl() const override;
   3362 
   3363 public:
   3364   // allocate space for exactly zero operands
   3365   void *operator new(size_t s) {
   3366     return User::operator new(s, 0);
   3367   }
   3368   explicit UnreachableInst(LLVMContext &C, Instruction *InsertBefore = nullptr);
   3369   explicit UnreachableInst(LLVMContext &C, BasicBlock *InsertAtEnd);
   3370 
   3371   unsigned getNumSuccessors() const { return 0; }
   3372 
   3373   // Methods for support type inquiry through isa, cast, and dyn_cast:
   3374   static inline bool classof(const Instruction *I) {
   3375     return I->getOpcode() == Instruction::Unreachable;
   3376   }
   3377   static inline bool classof(const Value *V) {
   3378     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   3379   }
   3380 private:
   3381   BasicBlock *getSuccessorV(unsigned idx) const override;
   3382   unsigned getNumSuccessorsV() const override;
   3383   void setSuccessorV(unsigned idx, BasicBlock *B) override;
   3384 };
   3385 
   3386 //===----------------------------------------------------------------------===//
   3387 //                                 TruncInst Class
   3388 //===----------------------------------------------------------------------===//
   3389 
   3390 /// \brief This class represents a truncation of integer types.
   3391 class TruncInst : public CastInst {
   3392 protected:
   3393   /// \brief Clone an identical TruncInst
   3394   TruncInst *clone_impl() const override;
   3395 
   3396 public:
   3397   /// \brief Constructor with insert-before-instruction semantics
   3398   TruncInst(
   3399     Value *S,                           ///< The value to be truncated
   3400     Type *Ty,                           ///< The (smaller) type to truncate to
   3401     const Twine &NameStr = "",          ///< A name for the new instruction
   3402     Instruction *InsertBefore = nullptr ///< Where to insert the new instruction
   3403   );
   3404 
   3405   /// \brief Constructor with insert-at-end-of-block semantics
   3406   TruncInst(
   3407     Value *S,                     ///< The value to be truncated
   3408     Type *Ty,                     ///< The (smaller) type to truncate to
   3409     const Twine &NameStr,         ///< A name for the new instruction
   3410     BasicBlock *InsertAtEnd       ///< The block to insert the instruction into
   3411   );
   3412 
   3413   /// \brief Methods for support type inquiry through isa, cast, and dyn_cast:
   3414   static inline bool classof(const Instruction *I) {
   3415     return I->getOpcode() == Trunc;
   3416   }
   3417   static inline bool classof(const Value *V) {
   3418     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   3419   }
   3420 };
   3421 
   3422 //===----------------------------------------------------------------------===//
   3423 //                                 ZExtInst Class
   3424 //===----------------------------------------------------------------------===//
   3425 
   3426 /// \brief This class represents zero extension of integer types.
   3427 class ZExtInst : public CastInst {
   3428 protected:
   3429   /// \brief Clone an identical ZExtInst
   3430   ZExtInst *clone_impl() const override;
   3431 
   3432 public:
   3433   /// \brief Constructor with insert-before-instruction semantics
   3434   ZExtInst(
   3435     Value *S,                           ///< The value to be zero extended
   3436     Type *Ty,                           ///< The type to zero extend to
   3437     const Twine &NameStr = "",          ///< A name for the new instruction
   3438     Instruction *InsertBefore = nullptr ///< Where to insert the new instruction
   3439   );
   3440 
   3441   /// \brief Constructor with insert-at-end semantics.
   3442   ZExtInst(
   3443     Value *S,                     ///< The value to be zero extended
   3444     Type *Ty,                     ///< The type to zero extend to
   3445     const Twine &NameStr,         ///< A name for the new instruction
   3446     BasicBlock *InsertAtEnd       ///< The block to insert the instruction into
   3447   );
   3448 
   3449   /// \brief Methods for support type inquiry through isa, cast, and dyn_cast:
   3450   static inline bool classof(const Instruction *I) {
   3451     return I->getOpcode() == ZExt;
   3452   }
   3453   static inline bool classof(const Value *V) {
   3454     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   3455   }
   3456 };
   3457 
   3458 //===----------------------------------------------------------------------===//
   3459 //                                 SExtInst Class
   3460 //===----------------------------------------------------------------------===//
   3461 
   3462 /// \brief This class represents a sign extension of integer types.
   3463 class SExtInst : public CastInst {
   3464 protected:
   3465   /// \brief Clone an identical SExtInst
   3466   SExtInst *clone_impl() const override;
   3467 
   3468 public:
   3469   /// \brief Constructor with insert-before-instruction semantics
   3470   SExtInst(
   3471     Value *S,                           ///< The value to be sign extended
   3472     Type *Ty,                           ///< The type to sign extend to
   3473     const Twine &NameStr = "",          ///< A name for the new instruction
   3474     Instruction *InsertBefore = nullptr ///< Where to insert the new instruction
   3475   );
   3476 
   3477   /// \brief Constructor with insert-at-end-of-block semantics
   3478   SExtInst(
   3479     Value *S,                     ///< The value to be sign extended
   3480     Type *Ty,                     ///< The type to sign extend to
   3481     const Twine &NameStr,         ///< A name for the new instruction
   3482     BasicBlock *InsertAtEnd       ///< The block to insert the instruction into
   3483   );
   3484 
   3485   /// \brief Methods for support type inquiry through isa, cast, and dyn_cast:
   3486   static inline bool classof(const Instruction *I) {
   3487     return I->getOpcode() == SExt;
   3488   }
   3489   static inline bool classof(const Value *V) {
   3490     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   3491   }
   3492 };
   3493 
   3494 //===----------------------------------------------------------------------===//
   3495 //                                 FPTruncInst Class
   3496 //===----------------------------------------------------------------------===//
   3497 
   3498 /// \brief This class represents a truncation of floating point types.
   3499 class FPTruncInst : public CastInst {
   3500 protected:
   3501   /// \brief Clone an identical FPTruncInst
   3502   FPTruncInst *clone_impl() const override;
   3503 
   3504 public:
   3505   /// \brief Constructor with insert-before-instruction semantics
   3506   FPTruncInst(
   3507     Value *S,                           ///< The value to be truncated
   3508     Type *Ty,                           ///< The type to truncate to
   3509     const Twine &NameStr = "",          ///< A name for the new instruction
   3510     Instruction *InsertBefore = nullptr ///< Where to insert the new instruction
   3511   );
   3512 
   3513   /// \brief Constructor with insert-before-instruction semantics
   3514   FPTruncInst(
   3515     Value *S,                     ///< The value to be truncated
   3516     Type *Ty,                     ///< The type to truncate to
   3517     const Twine &NameStr,         ///< A name for the new instruction
   3518     BasicBlock *InsertAtEnd       ///< The block to insert the instruction into
   3519   );
   3520 
   3521   /// \brief Methods for support type inquiry through isa, cast, and dyn_cast:
   3522   static inline bool classof(const Instruction *I) {
   3523     return I->getOpcode() == FPTrunc;
   3524   }
   3525   static inline bool classof(const Value *V) {
   3526     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   3527   }
   3528 };
   3529 
   3530 //===----------------------------------------------------------------------===//
   3531 //                                 FPExtInst Class
   3532 //===----------------------------------------------------------------------===//
   3533 
   3534 /// \brief This class represents an extension of floating point types.
   3535 class FPExtInst : public CastInst {
   3536 protected:
   3537   /// \brief Clone an identical FPExtInst
   3538   FPExtInst *clone_impl() const override;
   3539 
   3540 public:
   3541   /// \brief Constructor with insert-before-instruction semantics
   3542   FPExtInst(
   3543     Value *S,                           ///< The value to be extended
   3544     Type *Ty,                           ///< The type to extend to
   3545     const Twine &NameStr = "",          ///< A name for the new instruction
   3546     Instruction *InsertBefore = nullptr ///< Where to insert the new instruction
   3547   );
   3548 
   3549   /// \brief Constructor with insert-at-end-of-block semantics
   3550   FPExtInst(
   3551     Value *S,                     ///< The value to be extended
   3552     Type *Ty,                     ///< The type to extend to
   3553     const Twine &NameStr,         ///< A name for the new instruction
   3554     BasicBlock *InsertAtEnd       ///< The block to insert the instruction into
   3555   );
   3556 
   3557   /// \brief Methods for support type inquiry through isa, cast, and dyn_cast:
   3558   static inline bool classof(const Instruction *I) {
   3559     return I->getOpcode() == FPExt;
   3560   }
   3561   static inline bool classof(const Value *V) {
   3562     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   3563   }
   3564 };
   3565 
   3566 //===----------------------------------------------------------------------===//
   3567 //                                 UIToFPInst Class
   3568 //===----------------------------------------------------------------------===//
   3569 
   3570 /// \brief This class represents a cast unsigned integer to floating point.
   3571 class UIToFPInst : public CastInst {
   3572 protected:
   3573   /// \brief Clone an identical UIToFPInst
   3574   UIToFPInst *clone_impl() const override;
   3575 
   3576 public:
   3577   /// \brief Constructor with insert-before-instruction semantics
   3578   UIToFPInst(
   3579     Value *S,                           ///< The value to be converted
   3580     Type *Ty,                           ///< The type to convert to
   3581     const Twine &NameStr = "",          ///< A name for the new instruction
   3582     Instruction *InsertBefore = nullptr ///< Where to insert the new instruction
   3583   );
   3584 
   3585   /// \brief Constructor with insert-at-end-of-block semantics
   3586   UIToFPInst(
   3587     Value *S,                     ///< The value to be converted
   3588     Type *Ty,                     ///< The type to convert to
   3589     const Twine &NameStr,         ///< A name for the new instruction
   3590     BasicBlock *InsertAtEnd       ///< The block to insert the instruction into
   3591   );
   3592 
   3593   /// \brief Methods for support type inquiry through isa, cast, and dyn_cast:
   3594   static inline bool classof(const Instruction *I) {
   3595     return I->getOpcode() == UIToFP;
   3596   }
   3597   static inline bool classof(const Value *V) {
   3598     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   3599   }
   3600 };
   3601 
   3602 //===----------------------------------------------------------------------===//
   3603 //                                 SIToFPInst Class
   3604 //===----------------------------------------------------------------------===//
   3605 
   3606 /// \brief This class represents a cast from signed integer to floating point.
   3607 class SIToFPInst : public CastInst {
   3608 protected:
   3609   /// \brief Clone an identical SIToFPInst
   3610   SIToFPInst *clone_impl() const override;
   3611 
   3612 public:
   3613   /// \brief Constructor with insert-before-instruction semantics
   3614   SIToFPInst(
   3615     Value *S,                           ///< The value to be converted
   3616     Type *Ty,                           ///< The type to convert to
   3617     const Twine &NameStr = "",          ///< A name for the new instruction
   3618     Instruction *InsertBefore = nullptr ///< Where to insert the new instruction
   3619   );
   3620 
   3621   /// \brief Constructor with insert-at-end-of-block semantics
   3622   SIToFPInst(
   3623     Value *S,                     ///< The value to be converted
   3624     Type *Ty,                     ///< The type to convert to
   3625     const Twine &NameStr,         ///< A name for the new instruction
   3626     BasicBlock *InsertAtEnd       ///< The block to insert the instruction into
   3627   );
   3628 
   3629   /// \brief Methods for support type inquiry through isa, cast, and dyn_cast:
   3630   static inline bool classof(const Instruction *I) {
   3631     return I->getOpcode() == SIToFP;
   3632   }
   3633   static inline bool classof(const Value *V) {
   3634     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   3635   }
   3636 };
   3637 
   3638 //===----------------------------------------------------------------------===//
   3639 //                                 FPToUIInst Class
   3640 //===----------------------------------------------------------------------===//
   3641 
   3642 /// \brief This class represents a cast from floating point to unsigned integer
   3643 class FPToUIInst  : public CastInst {
   3644 protected:
   3645   /// \brief Clone an identical FPToUIInst
   3646   FPToUIInst *clone_impl() const override;
   3647 
   3648 public:
   3649   /// \brief Constructor with insert-before-instruction semantics
   3650   FPToUIInst(
   3651     Value *S,                           ///< The value to be converted
   3652     Type *Ty,                           ///< The type to convert to
   3653     const Twine &NameStr = "",          ///< A name for the new instruction
   3654     Instruction *InsertBefore = nullptr ///< Where to insert the new instruction
   3655   );
   3656 
   3657   /// \brief Constructor with insert-at-end-of-block semantics
   3658   FPToUIInst(
   3659     Value *S,                     ///< The value to be converted
   3660     Type *Ty,                     ///< The type to convert to
   3661     const Twine &NameStr,         ///< A name for the new instruction
   3662     BasicBlock *InsertAtEnd       ///< Where to insert the new instruction
   3663   );
   3664 
   3665   /// \brief Methods for support type inquiry through isa, cast, and dyn_cast:
   3666   static inline bool classof(const Instruction *I) {
   3667     return I->getOpcode() == FPToUI;
   3668   }
   3669   static inline bool classof(const Value *V) {
   3670     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   3671   }
   3672 };
   3673 
   3674 //===----------------------------------------------------------------------===//
   3675 //                                 FPToSIInst Class
   3676 //===----------------------------------------------------------------------===//
   3677 
   3678 /// \brief This class represents a cast from floating point to signed integer.
   3679 class FPToSIInst  : public CastInst {
   3680 protected:
   3681   /// \brief Clone an identical FPToSIInst
   3682   FPToSIInst *clone_impl() const override;
   3683 
   3684 public:
   3685   /// \brief Constructor with insert-before-instruction semantics
   3686   FPToSIInst(
   3687     Value *S,                           ///< The value to be converted
   3688     Type *Ty,                           ///< The type to convert to
   3689     const Twine &NameStr = "",          ///< A name for the new instruction
   3690     Instruction *InsertBefore = nullptr ///< Where to insert the new instruction
   3691   );
   3692 
   3693   /// \brief Constructor with insert-at-end-of-block semantics
   3694   FPToSIInst(
   3695     Value *S,                     ///< The value to be converted
   3696     Type *Ty,                     ///< The type to convert to
   3697     const Twine &NameStr,         ///< A name for the new instruction
   3698     BasicBlock *InsertAtEnd       ///< The block to insert the instruction into
   3699   );
   3700 
   3701   /// \brief Methods for support type inquiry through isa, cast, and dyn_cast:
   3702   static inline bool classof(const Instruction *I) {
   3703     return I->getOpcode() == FPToSI;
   3704   }
   3705   static inline bool classof(const Value *V) {
   3706     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   3707   }
   3708 };
   3709 
   3710 //===----------------------------------------------------------------------===//
   3711 //                                 IntToPtrInst Class
   3712 //===----------------------------------------------------------------------===//
   3713 
   3714 /// \brief This class represents a cast from an integer to a pointer.
   3715 class IntToPtrInst : public CastInst {
   3716 public:
   3717   /// \brief Constructor with insert-before-instruction semantics
   3718   IntToPtrInst(
   3719     Value *S,                           ///< The value to be converted
   3720     Type *Ty,                           ///< The type to convert to
   3721     const Twine &NameStr = "",          ///< A name for the new instruction
   3722     Instruction *InsertBefore = nullptr ///< Where to insert the new instruction
   3723   );
   3724 
   3725   /// \brief Constructor with insert-at-end-of-block semantics
   3726   IntToPtrInst(
   3727     Value *S,                     ///< The value to be converted
   3728     Type *Ty,                     ///< The type to convert to
   3729     const Twine &NameStr,         ///< A name for the new instruction
   3730     BasicBlock *InsertAtEnd       ///< The block to insert the instruction into
   3731   );
   3732 
   3733   /// \brief Clone an identical IntToPtrInst
   3734   IntToPtrInst *clone_impl() const override;
   3735 
   3736   /// \brief Returns the address space of this instruction's pointer type.
   3737   unsigned getAddressSpace() const {
   3738     return getType()->getPointerAddressSpace();
   3739   }
   3740 
   3741   // Methods for support type inquiry through isa, cast, and dyn_cast:
   3742   static inline bool classof(const Instruction *I) {
   3743     return I->getOpcode() == IntToPtr;
   3744   }
   3745   static inline bool classof(const Value *V) {
   3746     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   3747   }
   3748 };
   3749 
   3750 //===----------------------------------------------------------------------===//
   3751 //                                 PtrToIntInst Class
   3752 //===----------------------------------------------------------------------===//
   3753 
   3754 /// \brief This class represents a cast from a pointer to an integer
   3755 class PtrToIntInst : public CastInst {
   3756 protected:
   3757   /// \brief Clone an identical PtrToIntInst
   3758   PtrToIntInst *clone_impl() const override;
   3759 
   3760 public:
   3761   /// \brief Constructor with insert-before-instruction semantics
   3762   PtrToIntInst(
   3763     Value *S,                           ///< The value to be converted
   3764     Type *Ty,                           ///< The type to convert to
   3765     const Twine &NameStr = "",          ///< A name for the new instruction
   3766     Instruction *InsertBefore = nullptr ///< Where to insert the new instruction
   3767   );
   3768 
   3769   /// \brief Constructor with insert-at-end-of-block semantics
   3770   PtrToIntInst(
   3771     Value *S,                     ///< The value to be converted
   3772     Type *Ty,                     ///< The type to convert to
   3773     const Twine &NameStr,         ///< A name for the new instruction
   3774     BasicBlock *InsertAtEnd       ///< The block to insert the instruction into
   3775   );
   3776 
   3777   /// \brief Gets the pointer operand.
   3778   Value *getPointerOperand() { return getOperand(0); }
   3779   /// \brief Gets the pointer operand.
   3780   const Value *getPointerOperand() const { return getOperand(0); }
   3781   /// \brief Gets the operand index of the pointer operand.
   3782   static unsigned getPointerOperandIndex() { return 0U; }
   3783 
   3784   /// \brief Returns the address space of the pointer operand.
   3785   unsigned getPointerAddressSpace() const {
   3786     return getPointerOperand()->getType()->getPointerAddressSpace();
   3787   }
   3788 
   3789   // Methods for support type inquiry through isa, cast, and dyn_cast:
   3790   static inline bool classof(const Instruction *I) {
   3791     return I->getOpcode() == PtrToInt;
   3792   }
   3793   static inline bool classof(const Value *V) {
   3794     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   3795   }
   3796 };
   3797 
   3798 //===----------------------------------------------------------------------===//
   3799 //                             BitCastInst Class
   3800 //===----------------------------------------------------------------------===//
   3801 
   3802 /// \brief This class represents a no-op cast from one type to another.
   3803 class BitCastInst : public CastInst {
   3804 protected:
   3805   /// \brief Clone an identical BitCastInst
   3806   BitCastInst *clone_impl() const override;
   3807 
   3808 public:
   3809   /// \brief Constructor with insert-before-instruction semantics
   3810   BitCastInst(
   3811     Value *S,                           ///< The value to be casted
   3812     Type *Ty,                           ///< The type to casted to
   3813     const Twine &NameStr = "",          ///< A name for the new instruction
   3814     Instruction *InsertBefore = nullptr ///< Where to insert the new instruction
   3815   );
   3816 
   3817   /// \brief Constructor with insert-at-end-of-block semantics
   3818   BitCastInst(
   3819     Value *S,                     ///< The value to be casted
   3820     Type *Ty,                     ///< The type to casted to
   3821     const Twine &NameStr,         ///< A name for the new instruction
   3822     BasicBlock *InsertAtEnd       ///< The block to insert the instruction into
   3823   );
   3824 
   3825   // Methods for support type inquiry through isa, cast, and dyn_cast:
   3826   static inline bool classof(const Instruction *I) {
   3827     return I->getOpcode() == BitCast;
   3828   }
   3829   static inline bool classof(const Value *V) {
   3830     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   3831   }
   3832 };
   3833 
   3834 //===----------------------------------------------------------------------===//
   3835 //                          AddrSpaceCastInst Class
   3836 //===----------------------------------------------------------------------===//
   3837 
   3838 /// \brief This class represents a conversion between pointers from
   3839 /// one address space to another.
   3840 class AddrSpaceCastInst : public CastInst {
   3841 protected:
   3842   /// \brief Clone an identical AddrSpaceCastInst
   3843   AddrSpaceCastInst *clone_impl() const override;
   3844 
   3845 public:
   3846   /// \brief Constructor with insert-before-instruction semantics
   3847   AddrSpaceCastInst(
   3848     Value *S,                           ///< The value to be casted
   3849     Type *Ty,                           ///< The type to casted to
   3850     const Twine &NameStr = "",          ///< A name for the new instruction
   3851     Instruction *InsertBefore = nullptr ///< Where to insert the new instruction
   3852   );
   3853 
   3854   /// \brief Constructor with insert-at-end-of-block semantics
   3855   AddrSpaceCastInst(
   3856     Value *S,                     ///< The value to be casted
   3857     Type *Ty,                     ///< The type to casted to
   3858     const Twine &NameStr,         ///< A name for the new instruction
   3859     BasicBlock *InsertAtEnd       ///< The block to insert the instruction into
   3860   );
   3861 
   3862   // Methods for support type inquiry through isa, cast, and dyn_cast:
   3863   static inline bool classof(const Instruction *I) {
   3864     return I->getOpcode() == AddrSpaceCast;
   3865   }
   3866   static inline bool classof(const Value *V) {
   3867     return isa<Instruction>(V) && classof(cast<Instruction>(V));
   3868   }
   3869 };
   3870 
   3871 } // End llvm namespace
   3872 
   3873 #endif
   3874