//===-- llvm/Instruction.h - Instruction class definition -------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // 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/None.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/Casting.h" #include <algorithm> #include <cassert> #include <cstdint> #include <utility> namespace llvm { class BasicBlock; class FastMathFlags; class MDNode; 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. enum { /// This is a bit stored in the SubClassData field which indicates whether /// this instruction has metadata attached to it or not. HasMetadataBit = 1 << 15 }; 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); /// 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); //===--------------------------------------------------------------------===// // 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 isBinaryOp() const { return isBinaryOp(getOpcode()); } bool isShift() { return isShift(getOpcode()); } bool isCast() const { return isCast(getOpcode()); } bool isFuncletPad() const { return isFuncletPad(getOpcode()); } static const char* getOpcodeName(unsigned OpCode); static inline bool isTerminator(unsigned OpCode) { return OpCode >= TermOpsBegin && OpCode < TermOpsEnd; } static inline bool isBinaryOp(unsigned Opcode) { return Opcode >= BinaryOpsBegin && Opcode < BinaryOpsEnd; } /// 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; } //===--------------------------------------------------------------------===// // Metadata manipulation. //===--------------------------------------------------------------------===// /// Return true if this instruction has any metadata attached to it. bool hasMetadata() const { return DbgLoc || hasMetadataHashEntry(); } /// Return true if this instruction has metadata attached to it other than a /// debug location. bool hasMetadataOtherThanDebugLoc() const { return hasMetadataHashEntry(); } /// 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 { if (hasMetadataOtherThanDebugLoc()) getAllMetadataOtherThanDebugLocImpl(MDs); } /// Fills the AAMDNodes structure with AA metadata from this instruction. /// When Merge is true, the existing AA metadata is merged with that from this /// instruction providing the most-general result. void getAAMetadata(AAMDNodes &N, bool Merge = false) const; /// 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. void dropUnknownNonDebugMetadata(ArrayRef<unsigned> KnownIDs); void dropUnknownNonDebugMetadata() { return dropUnknownNonDebugMetadata(None); } void dropUnknownNonDebugMetadata(unsigned ID1) { return dropUnknownNonDebugMetadata(makeArrayRef(ID1)); } void dropUnknownNonDebugMetadata(unsigned ID1, unsigned ID2) { unsigned IDs[] = {ID1, ID2}; return dropUnknownNonDebugMetadata(IDs); } /// @} /// Sets the metadata on this instruction from the AAMDNodes structure. void setAAMetadata(const AAMDNodes &N); /// Retrieve the raw weight values of a conditional branch or select. /// Returns true on success with profile weights filled in. /// Returns false if no metadata or invalid metadata was found. bool extractProfMetadata(uint64_t &TrueVal, uint64_t &FalseVal) const; /// 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; /// Updates branch_weights metadata by scaling it by \p S / \p T. void updateProfWeight(uint64_t S, uint64_t T); /// Sets the branch_weights metadata to \p W for CallInst. void setProfWeight(uint64_t W); /// 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 nsw 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; /// Determine whether the no signed wrap flag is set. bool hasNoSignedWrap() const; /// Drops flags that may cause this instruction to evaluate to poison despite /// having non-poison inputs. void dropPoisonGeneratingFlags(); /// Determine whether the exact flag is set. bool isExact() const; /// Set or clear the unsafe-algebra flag on this instruction, which must be an /// operator which supports this flag. See LangRef.html for the meaning of /// this flag. void setHasUnsafeAlgebra(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); /// 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 the unsafe-algebra flag is set. bool hasUnsafeAlgebra() const; /// Determine whether the no-NaNs flag is set. bool hasNoNaNs() const; /// Determine whether the no-infs flag is set. bool hasNoInfs() const; /// Determine whether the no-signed-zeros flag is set. bool hasNoSignedZeros() const; /// Determine whether the allow-reciprocal flag is set. bool hasAllowReciprocal() const; /// Determine whether the allow-contract flag is set. bool hasAllowContract() const; /// 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; /// 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); private: /// Return true if we have an entry in the on-the-side metadata hash. bool hasMetadataHashEntry() const { return (getSubclassDataFromValue() & HasMetadataBit) != 0; } // 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; void getAllMetadataOtherThanDebugLocImpl( SmallVectorImpl<std::pair<unsigned, MDNode *>> &) const; /// Clear all hashtable-based metadata from this instruction. void clearMetadataHashEntries(); 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 { return isCommutative(getOpcode()); } 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; /// Return true if this instruction may read memory. bool mayReadFromMemory() const; /// 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; /// Return true if this atomic instruction loads from memory. bool hasAtomicLoad() const; /// Return true if this atomic instruction stores to memory. bool hasAtomicStore() const; /// Return true if this instruction may throw an exception. bool mayThrow() const; /// 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. /// /// 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 { return mayWriteToMemory() || mayThrow(); } /// 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; } } /// 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; /// 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; /// 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. /// @brief Determine if one instruction is the same operation as another. bool isSameOperationAs(const Instruction *I, unsigned flags = 0) const; /// 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; /// 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 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>; // 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 setHasMetadataHashEntry(bool V) { setValueSubclassData((getSubclassDataFromValue() & ~HasMetadataBit) | (V ? HasMetadataBit : 0)); } void setParent(BasicBlock *P); protected: // Instruction subclasses can stick up to 15 bits of stuff into the // SubclassData field of instruction with these members. // Verify that only the low 15 bits are used. void setInstructionSubclassData(unsigned short D) { assert((D & HasMetadataBit) == 0 && "Out of range value put into field"); setValueSubclassData((getSubclassDataFromValue() & HasMetadataBit) | D); } unsigned getSubclassDataFromInstruction() const { return getSubclassDataFromValue() & ~HasMetadataBit; } 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