- //===-- llvm/Instruction.h - Instruction class definition -------*- C++ -*-===// 
- // 
- // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 
- // See https://llvm.org/LICENSE.txt for license information. 
- // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 
- // 
- //===----------------------------------------------------------------------===// 
- // 
- // This file contains the declaration of the Instruction class, which is the 
- // base class for all of the LLVM instructions. 
- // 
- //===----------------------------------------------------------------------===// 
-   
- #ifndef LLVM_IR_INSTRUCTION_H 
- #define LLVM_IR_INSTRUCTION_H 
-   
- #include "llvm/ADT/ArrayRef.h" 
- #include "llvm/ADT/Bitfields.h" 
- #include "llvm/ADT/StringRef.h" 
- #include "llvm/ADT/ilist_node.h" 
- #include "llvm/IR/DebugLoc.h" 
- #include "llvm/IR/SymbolTableListTraits.h" 
- #include "llvm/IR/User.h" 
- #include "llvm/IR/Value.h" 
- #include "llvm/Support/AtomicOrdering.h" 
- #include <cstdint> 
- #include <utility> 
-   
- namespace llvm { 
-   
- class BasicBlock; 
- class FastMathFlags; 
- class MDNode; 
- class Module; 
- struct AAMDNodes; 
-   
- template <> struct ilist_alloc_traits<Instruction> { 
-   static inline void deleteNode(Instruction *V); 
- }; 
-   
- class Instruction : public User, 
-                     public ilist_node_with_parent<Instruction, BasicBlock> { 
-   BasicBlock *Parent; 
-   DebugLoc DbgLoc;                         // 'dbg' Metadata cache. 
-   
-   /// Relative order of this instruction in its parent basic block. Used for 
-   /// O(1) local dominance checks between instructions. 
-   mutable unsigned Order = 0; 
-   
- protected: 
-   // The 15 first bits of `Value::SubclassData` are available for subclasses of 
-   // `Instruction` to use. 
-   using OpaqueField = Bitfield::Element<uint16_t, 0, 15>; 
-   
-   // Template alias so that all Instruction storing alignment use the same 
-   // definiton. 
-   // Valid alignments are powers of two from 2^0 to 2^MaxAlignmentExponent = 
-   // 2^32. We store them as Log2(Alignment), so we need 6 bits to encode the 33 
-   // possible values. 
-   template <unsigned Offset> 
-   using AlignmentBitfieldElementT = 
-       typename Bitfield::Element<unsigned, Offset, 6, 
-                                  Value::MaxAlignmentExponent>; 
-   
-   template <unsigned Offset> 
-   using BoolBitfieldElementT = typename Bitfield::Element<bool, Offset, 1>; 
-   
-   template <unsigned Offset> 
-   using AtomicOrderingBitfieldElementT = 
-       typename Bitfield::Element<AtomicOrdering, Offset, 3, 
-                                  AtomicOrdering::LAST>; 
-   
- private: 
-   // The last bit is used to store whether the instruction has metadata attached 
-   // or not. 
-   using HasMetadataField = Bitfield::Element<bool, 15, 1>; 
-   
- protected: 
-   ~Instruction(); // Use deleteValue() to delete a generic Instruction. 
-   
- public: 
-   Instruction(const Instruction &) = delete; 
-   Instruction &operator=(const Instruction &) = delete; 
-   
-   /// Specialize the methods defined in Value, as we know that an instruction 
-   /// can only be used by other instructions. 
-   Instruction       *user_back()       { return cast<Instruction>(*user_begin());} 
-   const Instruction *user_back() const { return cast<Instruction>(*user_begin());} 
-   
-   inline const BasicBlock *getParent() const { return Parent; } 
-   inline       BasicBlock *getParent()       { return Parent; } 
-   
-   /// Return the module owning the function this instruction belongs to 
-   /// or nullptr it the function does not have a module. 
-   /// 
-   /// Note: this is undefined behavior if the instruction does not have a 
-   /// parent, or the parent basic block does not have a parent function. 
-   const Module *getModule() const; 
-   Module *getModule() { 
-     return const_cast<Module *>( 
-                            static_cast<const Instruction *>(this)->getModule()); 
-   } 
-   
-   /// Return the function this instruction belongs to. 
-   /// 
-   /// Note: it is undefined behavior to call this on an instruction not 
-   /// currently inserted into a function. 
-   const Function *getFunction() const; 
-   Function *getFunction() { 
-     return const_cast<Function *>( 
-                          static_cast<const Instruction *>(this)->getFunction()); 
-   } 
-   
-   /// This method unlinks 'this' from the containing basic block, but does not 
-   /// delete it. 
-   void removeFromParent(); 
-   
-   /// This method unlinks 'this' from the containing basic block and deletes it. 
-   /// 
-   /// \returns an iterator pointing to the element after the erased one 
-   SymbolTableList<Instruction>::iterator eraseFromParent(); 
-   
-   /// Insert an unlinked instruction into a basic block immediately before 
-   /// the specified instruction. 
-   void insertBefore(Instruction *InsertPos); 
-   
-   /// Insert an unlinked instruction into a basic block immediately after the 
-   /// specified instruction. 
-   void insertAfter(Instruction *InsertPos); 
-   
-   /// Inserts an unlinked instruction into \p ParentBB at position \p It and 
-   /// returns the iterator of the inserted instruction. 
-   SymbolTableList<Instruction>::iterator 
-   insertInto(BasicBlock *ParentBB, SymbolTableList<Instruction>::iterator It); 
-   
-   /// Unlink this instruction from its current basic block and insert it into 
-   /// the basic block that MovePos lives in, right before MovePos. 
-   void moveBefore(Instruction *MovePos); 
-   
-   /// Unlink this instruction and insert into BB before I. 
-   /// 
-   /// \pre I is a valid iterator into BB. 
-   void moveBefore(BasicBlock &BB, SymbolTableList<Instruction>::iterator I); 
-   
-   /// Unlink this instruction from its current basic block and insert it into 
-   /// the basic block that MovePos lives in, right after MovePos. 
-   void moveAfter(Instruction *MovePos); 
-   
-   /// Given an instruction Other in the same basic block as this instruction, 
-   /// return true if this instruction comes before Other. In this worst case, 
-   /// this takes linear time in the number of instructions in the block. The 
-   /// results are cached, so in common cases when the block remains unmodified, 
-   /// it takes constant time. 
-   bool comesBefore(const Instruction *Other) const; 
-   
-   /// Get the first insertion point at which the result of this instruction 
-   /// is defined. This is *not* the directly following instruction in a number 
-   /// of cases, e.g. phi nodes or terminators that return values. This function 
-   /// may return null if the insertion after the definition is not possible, 
-   /// e.g. due to a catchswitch terminator. 
-   Instruction *getInsertionPointAfterDef(); 
-   
-   //===--------------------------------------------------------------------===// 
-   // Subclass classification. 
-   //===--------------------------------------------------------------------===// 
-   
-   /// Returns a member of one of the enums like Instruction::Add. 
-   unsigned getOpcode() const { return getValueID() - InstructionVal; } 
-   
-   const char *getOpcodeName() const { return getOpcodeName(getOpcode()); } 
-   bool isTerminator() const { return isTerminator(getOpcode()); } 
-   bool isUnaryOp() const { return isUnaryOp(getOpcode()); } 
-   bool isBinaryOp() const { return isBinaryOp(getOpcode()); } 
-   bool isIntDivRem() const { return isIntDivRem(getOpcode()); } 
-   bool isShift() const { return isShift(getOpcode()); } 
-   bool isCast() const { return isCast(getOpcode()); } 
-   bool isFuncletPad() const { return isFuncletPad(getOpcode()); } 
-   bool isExceptionalTerminator() const { 
-     return isExceptionalTerminator(getOpcode()); 
-   } 
-   
-   /// It checks if this instruction is the only user of at least one of 
-   /// its operands. 
-   bool isOnlyUserOfAnyOperand(); 
-   
-   static const char* getOpcodeName(unsigned OpCode); 
-   
-   static inline bool isTerminator(unsigned OpCode) { 
-     return OpCode >= TermOpsBegin && OpCode < TermOpsEnd; 
-   } 
-   
-   static inline bool isUnaryOp(unsigned Opcode) { 
-     return Opcode >= UnaryOpsBegin && Opcode < UnaryOpsEnd; 
-   } 
-   static inline bool isBinaryOp(unsigned Opcode) { 
-     return Opcode >= BinaryOpsBegin && Opcode < BinaryOpsEnd; 
-   } 
-   
-   static inline bool isIntDivRem(unsigned Opcode) { 
-     return Opcode == UDiv || Opcode == SDiv || Opcode == URem || Opcode == SRem; 
-   } 
-   
-   /// Determine if the Opcode is one of the shift instructions. 
-   static inline bool isShift(unsigned Opcode) { 
-     return Opcode >= Shl && Opcode <= AShr; 
-   } 
-   
-   /// Return true if this is a logical shift left or a logical shift right. 
-   inline bool isLogicalShift() const { 
-     return getOpcode() == Shl || getOpcode() == LShr; 
-   } 
-   
-   /// Return true if this is an arithmetic shift right. 
-   inline bool isArithmeticShift() const { 
-     return getOpcode() == AShr; 
-   } 
-   
-   /// Determine if the Opcode is and/or/xor. 
-   static inline bool isBitwiseLogicOp(unsigned Opcode) { 
-     return Opcode == And || Opcode == Or || Opcode == Xor; 
-   } 
-   
-   /// Return true if this is and/or/xor. 
-   inline bool isBitwiseLogicOp() const { 
-     return isBitwiseLogicOp(getOpcode()); 
-   } 
-   
-   /// Determine if the OpCode is one of the CastInst instructions. 
-   static inline bool isCast(unsigned OpCode) { 
-     return OpCode >= CastOpsBegin && OpCode < CastOpsEnd; 
-   } 
-   
-   /// Determine if the OpCode is one of the FuncletPadInst instructions. 
-   static inline bool isFuncletPad(unsigned OpCode) { 
-     return OpCode >= FuncletPadOpsBegin && OpCode < FuncletPadOpsEnd; 
-   } 
-   
-   /// Returns true if the OpCode is a terminator related to exception handling. 
-   static inline bool isExceptionalTerminator(unsigned OpCode) { 
-     switch (OpCode) { 
-     case Instruction::CatchSwitch: 
-     case Instruction::CatchRet: 
-     case Instruction::CleanupRet: 
-     case Instruction::Invoke: 
-     case Instruction::Resume: 
-       return true; 
-     default: 
-       return false; 
-     } 
-   } 
-   
-   //===--------------------------------------------------------------------===// 
-   // Metadata manipulation. 
-   //===--------------------------------------------------------------------===// 
-   
-   /// Return true if this instruction has any metadata attached to it. 
-   bool hasMetadata() const { return DbgLoc || Value::hasMetadata(); } 
-   
-   /// Return true if this instruction has metadata attached to it other than a 
-   /// debug location. 
-   bool hasMetadataOtherThanDebugLoc() const { return Value::hasMetadata(); } 
-   
-   /// Return true if this instruction has the given type of metadata attached. 
-   bool hasMetadata(unsigned KindID) const { 
-     return getMetadata(KindID) != nullptr; 
-   } 
-   
-   /// Return true if this instruction has the given type of metadata attached. 
-   bool hasMetadata(StringRef Kind) const { 
-     return getMetadata(Kind) != nullptr; 
-   } 
-   
-   /// Get the metadata of given kind attached to this Instruction. 
-   /// If the metadata is not found then return null. 
-   MDNode *getMetadata(unsigned KindID) const { 
-     if (!hasMetadata()) return nullptr; 
-     return getMetadataImpl(KindID); 
-   } 
-   
-   /// Get the metadata of given kind attached to this Instruction. 
-   /// If the metadata is not found then return null. 
-   MDNode *getMetadata(StringRef Kind) const { 
-     if (!hasMetadata()) return nullptr; 
-     return getMetadataImpl(Kind); 
-   } 
-   
-   /// Get all metadata attached to this Instruction. The first element of each 
-   /// pair returned is the KindID, the second element is the metadata value. 
-   /// This list is returned sorted by the KindID. 
-   void 
-   getAllMetadata(SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const { 
-     if (hasMetadata()) 
-       getAllMetadataImpl(MDs); 
-   } 
-   
-   /// This does the same thing as getAllMetadata, except that it filters out the 
-   /// debug location. 
-   void getAllMetadataOtherThanDebugLoc( 
-       SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const { 
-     Value::getAllMetadata(MDs); 
-   } 
-   
-   /// Set the metadata of the specified kind to the specified node. This updates 
-   /// or replaces metadata if already present, or removes it if Node is null. 
-   void setMetadata(unsigned KindID, MDNode *Node); 
-   void setMetadata(StringRef Kind, MDNode *Node); 
-   
-   /// Copy metadata from \p SrcInst to this instruction. \p WL, if not empty, 
-   /// specifies the list of meta data that needs to be copied. If \p WL is 
-   /// empty, all meta data will be copied. 
-   void copyMetadata(const Instruction &SrcInst, 
-                     ArrayRef<unsigned> WL = ArrayRef<unsigned>()); 
-   
-   /// If the instruction has "branch_weights" MD_prof metadata and the MDNode 
-   /// has three operands (including name string), swap the order of the 
-   /// metadata. 
-   void swapProfMetadata(); 
-   
-   /// Drop all unknown metadata except for debug locations. 
-   /// @{ 
-   /// Passes are required to drop metadata they don't understand. This is a 
-   /// convenience method for passes to do so. 
-   /// dropUndefImplyingAttrsAndUnknownMetadata should be used instead of 
-   /// this API if the Instruction being modified is a call. 
-   void dropUnknownNonDebugMetadata(ArrayRef<unsigned> KnownIDs); 
-   void dropUnknownNonDebugMetadata() { 
-     return dropUnknownNonDebugMetadata(std::nullopt); 
-   } 
-   void dropUnknownNonDebugMetadata(unsigned ID1) { 
-     return dropUnknownNonDebugMetadata(ArrayRef(ID1)); 
-   } 
-   void dropUnknownNonDebugMetadata(unsigned ID1, unsigned ID2) { 
-     unsigned IDs[] = {ID1, ID2}; 
-     return dropUnknownNonDebugMetadata(IDs); 
-   } 
-   /// @} 
-   
-   /// Adds an !annotation metadata node with \p Annotation to this instruction. 
-   /// If this instruction already has !annotation metadata, append \p Annotation 
-   /// to the existing node. 
-   void addAnnotationMetadata(StringRef Annotation); 
-   
-   /// Returns the AA metadata for this instruction. 
-   AAMDNodes getAAMetadata() const; 
-   
-   /// Sets the AA metadata on this instruction from the AAMDNodes structure. 
-   void setAAMetadata(const AAMDNodes &N); 
-   
-   /// Retrieve total raw weight values of a branch. 
-   /// Returns true on success with profile total weights filled in. 
-   /// Returns false if no metadata was found. 
-   bool extractProfTotalWeight(uint64_t &TotalVal) const; 
-   
-   /// Set the debug location information for this instruction. 
-   void setDebugLoc(DebugLoc Loc) { DbgLoc = std::move(Loc); } 
-   
-   /// Return the debug location for this node as a DebugLoc. 
-   const DebugLoc &getDebugLoc() const { return DbgLoc; } 
-   
-   /// Set or clear the nuw flag on this instruction, which must be an operator 
-   /// which supports this flag. See LangRef.html for the meaning of this flag. 
-   void setHasNoUnsignedWrap(bool b = true); 
-   
-   /// Set or clear the nsw flag on this instruction, which must be an operator 
-   /// which supports this flag. See LangRef.html for the meaning of this flag. 
-   void setHasNoSignedWrap(bool b = true); 
-   
-   /// Set or clear the exact flag on this instruction, which must be an operator 
-   /// which supports this flag. See LangRef.html for the meaning of this flag. 
-   void setIsExact(bool b = true); 
-   
-   /// Determine whether the no unsigned wrap flag is set. 
-   bool hasNoUnsignedWrap() const LLVM_READONLY; 
-   
-   /// Determine whether the no signed wrap flag is set. 
-   bool hasNoSignedWrap() const LLVM_READONLY; 
-   
-   /// Return true if this operator has flags which may cause this instruction 
-   /// to evaluate to poison despite having non-poison inputs. 
-   bool hasPoisonGeneratingFlags() const LLVM_READONLY; 
-   
-   /// Drops flags that may cause this instruction to evaluate to poison despite 
-   /// having non-poison inputs. 
-   void dropPoisonGeneratingFlags(); 
-   
-   /// Return true if this instruction has poison-generating metadata. 
-   bool hasPoisonGeneratingMetadata() const LLVM_READONLY; 
-   
-   /// Drops metadata that may generate poison. 
-   void dropPoisonGeneratingMetadata(); 
-   
-   /// Return true if this instruction has poison-generating flags or metadata. 
-   bool hasPoisonGeneratingFlagsOrMetadata() const { 
-     return hasPoisonGeneratingFlags() || hasPoisonGeneratingMetadata(); 
-   } 
-   
-   /// Drops flags and metadata that may generate poison. 
-   void dropPoisonGeneratingFlagsAndMetadata() { 
-     dropPoisonGeneratingFlags(); 
-     dropPoisonGeneratingMetadata(); 
-   } 
-   
-   /// This function drops non-debug unknown metadata (through 
-   /// dropUnknownNonDebugMetadata). For calls, it also drops parameter and  
-   /// return attributes that can cause undefined behaviour. Both of these should 
-   /// be done by passes which move instructions in IR. 
-   void 
-   dropUndefImplyingAttrsAndUnknownMetadata(ArrayRef<unsigned> KnownIDs = {}); 
-   
-   /// Determine whether the exact flag is set. 
-   bool isExact() const LLVM_READONLY; 
-   
-   /// Set or clear all fast-math-flags on this instruction, which must be an 
-   /// operator which supports this flag. See LangRef.html for the meaning of 
-   /// this flag. 
-   void setFast(bool B); 
-   
-   /// Set or clear the reassociation flag on this instruction, which must be 
-   /// an operator which supports this flag. See LangRef.html for the meaning of 
-   /// this flag. 
-   void setHasAllowReassoc(bool B); 
-   
-   /// Set or clear the no-nans flag on this instruction, which must be an 
-   /// operator which supports this flag. See LangRef.html for the meaning of 
-   /// this flag. 
-   void setHasNoNaNs(bool B); 
-   
-   /// Set or clear the no-infs flag on this instruction, which must be an 
-   /// operator which supports this flag. See LangRef.html for the meaning of 
-   /// this flag. 
-   void setHasNoInfs(bool B); 
-   
-   /// Set or clear the no-signed-zeros flag on this instruction, which must be 
-   /// an operator which supports this flag. See LangRef.html for the meaning of 
-   /// this flag. 
-   void setHasNoSignedZeros(bool B); 
-   
-   /// Set or clear the allow-reciprocal flag on this instruction, which must be 
-   /// an operator which supports this flag. See LangRef.html for the meaning of 
-   /// this flag. 
-   void setHasAllowReciprocal(bool B); 
-   
-   /// Set or clear the allow-contract flag on this instruction, which must be 
-   /// an operator which supports this flag. See LangRef.html for the meaning of 
-   /// this flag. 
-   void setHasAllowContract(bool B); 
-   
-   /// Set or clear the approximate-math-functions flag on this instruction, 
-   /// which must be an operator which supports this flag. See LangRef.html for 
-   /// the meaning of this flag. 
-   void setHasApproxFunc(bool B); 
-   
-   /// Convenience function for setting multiple fast-math flags on this 
-   /// instruction, which must be an operator which supports these flags. See 
-   /// LangRef.html for the meaning of these flags. 
-   void setFastMathFlags(FastMathFlags FMF); 
-   
-   /// Convenience function for transferring all fast-math flag values to this 
-   /// instruction, which must be an operator which supports these flags. See 
-   /// LangRef.html for the meaning of these flags. 
-   void copyFastMathFlags(FastMathFlags FMF); 
-   
-   /// Determine whether all fast-math-flags are set. 
-   bool isFast() const LLVM_READONLY; 
-   
-   /// Determine whether the allow-reassociation flag is set. 
-   bool hasAllowReassoc() const LLVM_READONLY; 
-   
-   /// Determine whether the no-NaNs flag is set. 
-   bool hasNoNaNs() const LLVM_READONLY; 
-   
-   /// Determine whether the no-infs flag is set. 
-   bool hasNoInfs() const LLVM_READONLY; 
-   
-   /// Determine whether the no-signed-zeros flag is set. 
-   bool hasNoSignedZeros() const LLVM_READONLY; 
-   
-   /// Determine whether the allow-reciprocal flag is set. 
-   bool hasAllowReciprocal() const LLVM_READONLY; 
-   
-   /// Determine whether the allow-contract flag is set. 
-   bool hasAllowContract() const LLVM_READONLY; 
-   
-   /// Determine whether the approximate-math-functions flag is set. 
-   bool hasApproxFunc() const LLVM_READONLY; 
-   
-   /// Convenience function for getting all the fast-math flags, which must be an 
-   /// operator which supports these flags. See LangRef.html for the meaning of 
-   /// these flags. 
-   FastMathFlags getFastMathFlags() const LLVM_READONLY; 
-   
-   /// Copy I's fast-math flags 
-   void copyFastMathFlags(const Instruction *I); 
-   
-   /// Convenience method to copy supported exact, fast-math, and (optionally) 
-   /// wrapping flags from V to this instruction. 
-   void copyIRFlags(const Value *V, bool IncludeWrapFlags = true); 
-   
-   /// Logical 'and' of any supported wrapping, exact, and fast-math flags of 
-   /// V and this instruction. 
-   void andIRFlags(const Value *V); 
-   
-   /// Merge 2 debug locations and apply it to the Instruction. If the 
-   /// instruction is a CallIns, we need to traverse the inline chain to find 
-   /// the common scope. This is not efficient for N-way merging as each time 
-   /// you merge 2 iterations, you need to rebuild the hashmap to find the 
-   /// common scope. However, we still choose this API because: 
-   ///  1) Simplicity: it takes 2 locations instead of a list of locations. 
-   ///  2) In worst case, it increases the complexity from O(N*I) to 
-   ///     O(2*N*I), where N is # of Instructions to merge, and I is the 
-   ///     maximum level of inline stack. So it is still linear. 
-   ///  3) Merging of call instructions should be extremely rare in real 
-   ///     applications, thus the N-way merging should be in code path. 
-   /// The DebugLoc attached to this instruction will be overwritten by the 
-   /// merged DebugLoc. 
-   void applyMergedLocation(const DILocation *LocA, const DILocation *LocB); 
-   
-   /// Updates the debug location given that the instruction has been hoisted 
-   /// from a block to a predecessor of that block. 
-   /// Note: it is undefined behavior to call this on an instruction not 
-   /// currently inserted into a function. 
-   void updateLocationAfterHoist(); 
-   
-   /// Drop the instruction's debug location. This does not guarantee removal 
-   /// of the !dbg source location attachment, as it must set a line 0 location 
-   /// with scope information attached on call instructions. To guarantee 
-   /// removal of the !dbg attachment, use the \ref setDebugLoc() API. 
-   /// Note: it is undefined behavior to call this on an instruction not 
-   /// currently inserted into a function. 
-   void dropLocation(); 
-   
-   /// Merge the DIAssignID metadata from this instruction and those attached to 
-   /// instructions in \p SourceInstructions. This process performs a RAUW on 
-   /// the MetadataAsValue uses of the merged DIAssignID nodes. Not every 
-   /// instruction in \p SourceInstructions needs to have DIAssignID 
-   /// metadata. If none of them do then nothing happens. If this instruction 
-   /// does not have a DIAssignID attachment but at least one in \p 
-   /// SourceInstructions does then the merged one will be attached to 
-   /// it. However, instructions without attachments in \p SourceInstructions 
-   /// are not modified. 
-   void mergeDIAssignID(ArrayRef<const Instruction *> SourceInstructions); 
-   
- private: 
-   // These are all implemented in Metadata.cpp. 
-   MDNode *getMetadataImpl(unsigned KindID) const; 
-   MDNode *getMetadataImpl(StringRef Kind) const; 
-   void 
-   getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned, MDNode *>> &) const; 
-   
-   /// Update the LLVMContext ID-to-Instruction(s) mapping. If \p ID is nullptr 
-   /// then clear the mapping for this instruction. 
-   void updateDIAssignIDMapping(DIAssignID *ID); 
-   
- public: 
-   //===--------------------------------------------------------------------===// 
-   // Predicates and helper methods. 
-   //===--------------------------------------------------------------------===// 
-   
-   /// Return true if the instruction is associative: 
-   /// 
-   ///   Associative operators satisfy:  x op (y op z) === (x op y) op z 
-   /// 
-   /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative. 
-   /// 
-   bool isAssociative() const LLVM_READONLY; 
-   static bool isAssociative(unsigned Opcode) { 
-     return Opcode == And || Opcode == Or || Opcode == Xor || 
-            Opcode == Add || Opcode == Mul; 
-   } 
-   
-   /// Return true if the instruction is commutative: 
-   /// 
-   ///   Commutative operators satisfy: (x op y) === (y op x) 
-   /// 
-   /// In LLVM, these are the commutative operators, plus SetEQ and SetNE, when 
-   /// applied to any type. 
-   /// 
-   bool isCommutative() const LLVM_READONLY; 
-   static bool isCommutative(unsigned Opcode) { 
-     switch (Opcode) { 
-     case Add: case FAdd: 
-     case Mul: case FMul: 
-     case And: case Or: case Xor: 
-       return true; 
-     default: 
-       return false; 
-   } 
-   } 
-   
-   /// Return true if the instruction is idempotent: 
-   /// 
-   ///   Idempotent operators satisfy:  x op x === x 
-   /// 
-   /// In LLVM, the And and Or operators are idempotent. 
-   /// 
-   bool isIdempotent() const { return isIdempotent(getOpcode()); } 
-   static bool isIdempotent(unsigned Opcode) { 
-     return Opcode == And || Opcode == Or; 
-   } 
-   
-   /// Return true if the instruction is nilpotent: 
-   /// 
-   ///   Nilpotent operators satisfy:  x op x === Id, 
-   /// 
-   ///   where Id is the identity for the operator, i.e. a constant such that 
-   ///     x op Id === x and Id op x === x for all x. 
-   /// 
-   /// In LLVM, the Xor operator is nilpotent. 
-   /// 
-   bool isNilpotent() const { return isNilpotent(getOpcode()); } 
-   static bool isNilpotent(unsigned Opcode) { 
-     return Opcode == Xor; 
-   } 
-   
-   /// Return true if this instruction may modify memory. 
-   bool mayWriteToMemory() const LLVM_READONLY; 
-   
-   /// Return true if this instruction may read memory. 
-   bool mayReadFromMemory() const LLVM_READONLY; 
-   
-   /// Return true if this instruction may read or write memory. 
-   bool mayReadOrWriteMemory() const { 
-     return mayReadFromMemory() || mayWriteToMemory(); 
-   } 
-   
-   /// Return true if this instruction has an AtomicOrdering of unordered or 
-   /// higher. 
-   bool isAtomic() const LLVM_READONLY; 
-   
-   /// Return true if this atomic instruction loads from memory. 
-   bool hasAtomicLoad() const LLVM_READONLY; 
-   
-   /// Return true if this atomic instruction stores to memory. 
-   bool hasAtomicStore() const LLVM_READONLY; 
-   
-   /// Return true if this instruction has a volatile memory access. 
-   bool isVolatile() const LLVM_READONLY; 
-   
-   /// Return true if this instruction may throw an exception. 
-   bool mayThrow() const LLVM_READONLY; 
-   
-   /// Return true if this instruction behaves like a memory fence: it can load 
-   /// or store to memory location without being given a memory location. 
-   bool isFenceLike() const { 
-     switch (getOpcode()) { 
-     default: 
-       return false; 
-     // This list should be kept in sync with the list in mayWriteToMemory for 
-     // all opcodes which don't have a memory location. 
-     case Instruction::Fence: 
-     case Instruction::CatchPad: 
-     case Instruction::CatchRet: 
-     case Instruction::Call: 
-     case Instruction::Invoke: 
-       return true; 
-     } 
-   } 
-   
-   /// Return true if the instruction may have side effects. 
-   /// 
-   /// Side effects are: 
-   ///  * Writing to memory. 
-   ///  * Unwinding. 
-   ///  * Not returning (e.g. an infinite loop). 
-   /// 
-   /// Note that this does not consider malloc and alloca to have side 
-   /// effects because the newly allocated memory is completely invisible to 
-   /// instructions which don't use the returned value.  For cases where this 
-   /// matters, isSafeToSpeculativelyExecute may be more appropriate. 
-   bool mayHaveSideEffects() const LLVM_READONLY; 
-   
-   /// Return true if the instruction can be removed if the result is unused. 
-   /// 
-   /// When constant folding some instructions cannot be removed even if their 
-   /// results are unused. Specifically terminator instructions and calls that 
-   /// may have side effects cannot be removed without semantically changing the 
-   /// generated program. 
-   bool isSafeToRemove() const LLVM_READONLY; 
-   
-   /// Return true if the instruction will return (unwinding is considered as 
-   /// a form of returning control flow here). 
-   bool willReturn() const LLVM_READONLY; 
-   
-   /// Return true if the instruction is a variety of EH-block. 
-   bool isEHPad() const { 
-     switch (getOpcode()) { 
-     case Instruction::CatchSwitch: 
-     case Instruction::CatchPad: 
-     case Instruction::CleanupPad: 
-     case Instruction::LandingPad: 
-       return true; 
-     default: 
-       return false; 
-     } 
-   } 
-   
-   /// Return true if the instruction is a llvm.lifetime.start or 
-   /// llvm.lifetime.end marker. 
-   bool isLifetimeStartOrEnd() const LLVM_READONLY; 
-   
-   /// Return true if the instruction is a llvm.launder.invariant.group or 
-   /// llvm.strip.invariant.group. 
-   bool isLaunderOrStripInvariantGroup() const LLVM_READONLY; 
-   
-   /// Return true if the instruction is a DbgInfoIntrinsic or PseudoProbeInst. 
-   bool isDebugOrPseudoInst() const LLVM_READONLY; 
-   
-   /// Return a pointer to the next non-debug instruction in the same basic 
-   /// block as 'this', or nullptr if no such instruction exists. Skip any pseudo 
-   /// operations if \c SkipPseudoOp is true. 
-   const Instruction * 
-   getNextNonDebugInstruction(bool SkipPseudoOp = false) const; 
-   Instruction *getNextNonDebugInstruction(bool SkipPseudoOp = false) { 
-     return const_cast<Instruction *>( 
-         static_cast<const Instruction *>(this)->getNextNonDebugInstruction( 
-             SkipPseudoOp)); 
-   } 
-   
-   /// Return a pointer to the previous non-debug instruction in the same basic 
-   /// block as 'this', or nullptr if no such instruction exists. Skip any pseudo 
-   /// operations if \c SkipPseudoOp is true. 
-   const Instruction * 
-   getPrevNonDebugInstruction(bool SkipPseudoOp = false) const; 
-   Instruction *getPrevNonDebugInstruction(bool SkipPseudoOp = false) { 
-     return const_cast<Instruction *>( 
-         static_cast<const Instruction *>(this)->getPrevNonDebugInstruction( 
-             SkipPseudoOp)); 
-   } 
-   
-   /// Create a copy of 'this' instruction that is identical in all ways except 
-   /// the following: 
-   ///   * The instruction has no parent 
-   ///   * The instruction has no name 
-   /// 
-   Instruction *clone() const; 
-   
-   /// Return true if the specified instruction is exactly identical to the 
-   /// current one. This means that all operands match and any extra information 
-   /// (e.g. load is volatile) agree. 
-   bool isIdenticalTo(const Instruction *I) const LLVM_READONLY; 
-   
-   /// This is like isIdenticalTo, except that it ignores the 
-   /// SubclassOptionalData flags, which may specify conditions under which the 
-   /// instruction's result is undefined. 
-   bool isIdenticalToWhenDefined(const Instruction *I) const LLVM_READONLY; 
-   
-   /// When checking for operation equivalence (using isSameOperationAs) it is 
-   /// sometimes useful to ignore certain attributes. 
-   enum OperationEquivalenceFlags { 
-     /// Check for equivalence ignoring load/store alignment. 
-     CompareIgnoringAlignment = 1<<0, 
-     /// Check for equivalence treating a type and a vector of that type 
-     /// as equivalent. 
-     CompareUsingScalarTypes = 1<<1 
-   }; 
-   
-   /// This function determines if the specified instruction executes the same 
-   /// operation as the current one. This means that the opcodes, type, operand 
-   /// types and any other factors affecting the operation must be the same. This 
-   /// is similar to isIdenticalTo except the operands themselves don't have to 
-   /// be identical. 
-   /// @returns true if the specified instruction is the same operation as 
-   /// the current one. 
-   /// Determine if one instruction is the same operation as another. 
-   bool isSameOperationAs(const Instruction *I, unsigned flags = 0) const LLVM_READONLY; 
-   
-   /// Return true if there are any uses of this instruction in blocks other than 
-   /// the specified block. Note that PHI nodes are considered to evaluate their 
-   /// operands in the corresponding predecessor block. 
-   bool isUsedOutsideOfBlock(const BasicBlock *BB) const LLVM_READONLY; 
-   
-   /// Return the number of successors that this instruction has. The instruction 
-   /// must be a terminator. 
-   unsigned getNumSuccessors() const LLVM_READONLY; 
-   
-   /// Return the specified successor. This instruction must be a terminator. 
-   BasicBlock *getSuccessor(unsigned Idx) const LLVM_READONLY; 
-   
-   /// Update the specified successor to point at the provided block. This 
-   /// instruction must be a terminator. 
-   void setSuccessor(unsigned Idx, BasicBlock *BB); 
-   
-   /// Replace specified successor OldBB to point at the provided block. 
-   /// This instruction must be a terminator. 
-   void replaceSuccessorWith(BasicBlock *OldBB, BasicBlock *NewBB); 
-   
-   /// Methods for support type inquiry through isa, cast, and dyn_cast: 
-   static bool classof(const Value *V) { 
-     return V->getValueID() >= Value::InstructionVal; 
-   } 
-   
-   //---------------------------------------------------------------------- 
-   // Exported enumerations. 
-   // 
-   enum TermOps {       // These terminate basic blocks 
- #define  FIRST_TERM_INST(N)             TermOpsBegin = N, 
- #define HANDLE_TERM_INST(N, OPC, CLASS) OPC = N, 
- #define   LAST_TERM_INST(N)             TermOpsEnd = N+1 
- #include "llvm/IR/Instruction.def" 
-   }; 
-   
-   enum UnaryOps { 
- #define  FIRST_UNARY_INST(N)             UnaryOpsBegin = N, 
- #define HANDLE_UNARY_INST(N, OPC, CLASS) OPC = N, 
- #define   LAST_UNARY_INST(N)             UnaryOpsEnd = N+1 
- #include "llvm/IR/Instruction.def" 
-   }; 
-   
-   enum BinaryOps { 
- #define  FIRST_BINARY_INST(N)             BinaryOpsBegin = N, 
- #define HANDLE_BINARY_INST(N, OPC, CLASS) OPC = N, 
- #define   LAST_BINARY_INST(N)             BinaryOpsEnd = N+1 
- #include "llvm/IR/Instruction.def" 
-   }; 
-   
-   enum MemoryOps { 
- #define  FIRST_MEMORY_INST(N)             MemoryOpsBegin = N, 
- #define HANDLE_MEMORY_INST(N, OPC, CLASS) OPC = N, 
- #define   LAST_MEMORY_INST(N)             MemoryOpsEnd = N+1 
- #include "llvm/IR/Instruction.def" 
-   }; 
-   
-   enum CastOps { 
- #define  FIRST_CAST_INST(N)             CastOpsBegin = N, 
- #define HANDLE_CAST_INST(N, OPC, CLASS) OPC = N, 
- #define   LAST_CAST_INST(N)             CastOpsEnd = N+1 
- #include "llvm/IR/Instruction.def" 
-   }; 
-   
-   enum FuncletPadOps { 
- #define  FIRST_FUNCLETPAD_INST(N)             FuncletPadOpsBegin = N, 
- #define HANDLE_FUNCLETPAD_INST(N, OPC, CLASS) OPC = N, 
- #define   LAST_FUNCLETPAD_INST(N)             FuncletPadOpsEnd = N+1 
- #include "llvm/IR/Instruction.def" 
-   }; 
-   
-   enum OtherOps { 
- #define  FIRST_OTHER_INST(N)             OtherOpsBegin = N, 
- #define HANDLE_OTHER_INST(N, OPC, CLASS) OPC = N, 
- #define   LAST_OTHER_INST(N)             OtherOpsEnd = N+1 
- #include "llvm/IR/Instruction.def" 
-   }; 
-   
- private: 
-   friend class SymbolTableListTraits<Instruction>; 
-   friend class BasicBlock; // For renumbering. 
-   
-   // Shadow Value::setValueSubclassData with a private forwarding method so that 
-   // subclasses cannot accidentally use it. 
-   void setValueSubclassData(unsigned short D) { 
-     Value::setValueSubclassData(D); 
-   } 
-   
-   unsigned short getSubclassDataFromValue() const { 
-     return Value::getSubclassDataFromValue(); 
-   } 
-   
-   void setParent(BasicBlock *P); 
-   
- protected: 
-   // Instruction subclasses can stick up to 15 bits of stuff into the 
-   // SubclassData field of instruction with these members. 
-   
-   template <typename BitfieldElement> 
-   typename BitfieldElement::Type getSubclassData() const { 
-     static_assert( 
-         std::is_same<BitfieldElement, HasMetadataField>::value || 
-             !Bitfield::isOverlapping<BitfieldElement, HasMetadataField>(), 
-         "Must not overlap with the metadata bit"); 
-     return Bitfield::get<BitfieldElement>(getSubclassDataFromValue()); 
-   } 
-   
-   template <typename BitfieldElement> 
-   void setSubclassData(typename BitfieldElement::Type Value) { 
-     static_assert( 
-         std::is_same<BitfieldElement, HasMetadataField>::value || 
-             !Bitfield::isOverlapping<BitfieldElement, HasMetadataField>(), 
-         "Must not overlap with the metadata bit"); 
-     auto Storage = getSubclassDataFromValue(); 
-     Bitfield::set<BitfieldElement>(Storage, Value); 
-     setValueSubclassData(Storage); 
-   } 
-   
-   Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps, 
-               Instruction *InsertBefore = nullptr); 
-   Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps, 
-               BasicBlock *InsertAtEnd); 
-   
- private: 
-   /// Create a copy of this instruction. 
-   Instruction *cloneImpl() const; 
- }; 
-   
- inline void ilist_alloc_traits<Instruction>::deleteNode(Instruction *V) { 
-   V->deleteValue(); 
- } 
-   
- } // end namespace llvm 
-   
- #endif // LLVM_IR_INSTRUCTION_H 
-