LLVM API Documentation

Instruction.h

Go to the documentation of this file.
00001 //===-- llvm/Instruction.h - Instruction class definition -------*- C++ -*-===//
00002 //
00003 //                     The LLVM Compiler Infrastructure
00004 //
00005 // This file was developed by the LLVM research group and is distributed under
00006 // the University of Illinois Open Source License. See LICENSE.TXT for details.
00007 //
00008 //===----------------------------------------------------------------------===//
00009 //
00010 // This file contains the declaration of the Instruction class, which is the
00011 // base class for all of the LLVM instructions.
00012 //
00013 //===----------------------------------------------------------------------===//
00014 
00015 #ifndef LLVM_INSTRUCTION_H
00016 #define LLVM_INSTRUCTION_H
00017 
00018 #include "llvm/User.h"
00019 
00020 namespace llvm {
00021 
00022 struct AssemblyAnnotationWriter;
00023 class BinaryOperator;
00024 
00025 template<typename SC> struct ilist_traits;
00026 template<typename ValueSubClass, typename ItemParentClass, typename SymTabClass,
00027          typename SubClass> class SymbolTableListTraits;
00028 
00029 class Instruction : public User {
00030   void operator=(const Instruction &);     // Do not implement
00031   Instruction(const Instruction &);        // Do not implement
00032 
00033   BasicBlock *Parent;
00034   Instruction *Prev, *Next; // Next and Prev links for our intrusive linked list
00035 
00036   void setNext(Instruction *N) { Next = N; }
00037   void setPrev(Instruction *N) { Prev = N; }
00038 
00039   friend class SymbolTableListTraits<Instruction, BasicBlock, Function,
00040                                      ilist_traits<Instruction> >;
00041   void setParent(BasicBlock *P);
00042 
00043 private:
00044   // FIXME: This is a dirty hack.  Setcc instructions shouldn't encode the CC
00045   // into the opcode field.  When they don't, this will be unneeded.
00046   void setOpcode(unsigned NewOpcode);
00047   friend class BinaryOperator;
00048 protected:
00049   Instruction(const Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
00050               const std::string &Name = "",
00051               Instruction *InsertBefore = 0);
00052   Instruction(const Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
00053               const std::string &Name, BasicBlock *InsertAtEnd);
00054 public:
00055 
00056   ~Instruction() {
00057     assert(Parent == 0 && "Instruction still linked in the program!");
00058   }
00059 
00060   /// mayWriteToMemory - Return true if this instruction may modify memory.
00061   ///
00062   virtual bool mayWriteToMemory() const { return false; }
00063 
00064   /// clone() - Create a copy of 'this' instruction that is identical in all
00065   /// ways except the following:
00066   ///   * The instruction has no parent
00067   ///   * The instruction has no name
00068   ///
00069   virtual Instruction *clone() const = 0;
00070 
00071   /// isIdenticalTo - Return true if the specified instruction is exactly
00072   /// identical to the current one.  This means that all operands match and any
00073   /// extra information (e.g. load is volatile) agree.
00074   bool isIdenticalTo(Instruction *I) const;
00075 
00076 
00077   // Accessor methods...
00078   //
00079   inline const BasicBlock *getParent() const { return Parent; }
00080   inline       BasicBlock *getParent()       { return Parent; }
00081 
00082   // getNext/Prev - Return the next or previous instruction in the list.  The
00083   // last node in the list is a terminator instruction.
00084         Instruction *getNext()       { return Next; }
00085   const Instruction *getNext() const { return Next; }
00086         Instruction *getPrev()       { return Prev; }
00087   const Instruction *getPrev() const { return Prev; }
00088 
00089   /// removeFromParent - This method unlinks 'this' from the containing basic
00090   /// block, but does not delete it.
00091   ///
00092   void removeFromParent();
00093 
00094   /// eraseFromParent - This method unlinks 'this' from the containing basic
00095   /// block and deletes it.
00096   ///
00097   void eraseFromParent();
00098 
00099   /// moveBefore - Unlink this instruction from its current basic block and
00100   /// insert it into the basic block that MovePos lives in, right before
00101   /// MovePos.
00102   void moveBefore(Instruction *MovePos);
00103 
00104   // ---------------------------------------------------------------------------
00105   /// Subclass classification... getOpcode() returns a member of
00106   /// one of the enums that is coming soon (down below)...
00107   ///
00108   unsigned getOpcode() const { return getValueType() - InstructionVal; }
00109   virtual const char *getOpcodeName() const {
00110     return getOpcodeName(getOpcode());
00111   }
00112   static const char* getOpcodeName(unsigned OpCode);
00113 
00114   static inline bool isTerminator(unsigned OpCode) {
00115     return OpCode >= TermOpsBegin && OpCode < TermOpsEnd;
00116   }
00117 
00118   inline bool isTerminator() const {   // Instance of TerminatorInst?
00119     return isTerminator(getOpcode());
00120   }
00121 
00122   inline bool isBinaryOp() const {
00123     return getOpcode() >= BinaryOpsBegin && getOpcode() < BinaryOpsEnd;
00124   }
00125 
00126   /// isAssociative - Return true if the instruction is associative:
00127   ///
00128   ///   Associative operators satisfy:  x op (y op z) === (x op y) op z
00129   ///
00130   /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative, when
00131   /// not applied to floating point types.
00132   ///
00133   bool isAssociative() const { return isAssociative(getOpcode(), getType()); }
00134   static bool isAssociative(unsigned op, const Type *Ty);
00135 
00136   /// isCommutative - Return true if the instruction is commutative:
00137   ///
00138   ///   Commutative operators satisfy: (x op y) === (y op x)
00139   ///
00140   /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
00141   /// applied to any type.
00142   ///
00143   bool isCommutative() const { return isCommutative(getOpcode()); }
00144   static bool isCommutative(unsigned op);
00145 
00146   /// isRelational - Return true if the instruction is a Set* instruction:
00147   ///
00148   bool isRelational() const { return isRelational(getOpcode()); }
00149   static bool isRelational(unsigned op);
00150 
00151 
00152   /// isTrappingInstruction - Return true if the instruction may trap.
00153   ///
00154   bool isTrapping() const {
00155     return isTrapping(getOpcode());
00156   }
00157   static bool isTrapping(unsigned op);
00158 
00159   virtual void print(std::ostream &OS) const { print(OS, 0); }
00160   void print(std::ostream &OS, AssemblyAnnotationWriter *AAW) const;
00161 
00162   /// Methods for support type inquiry through isa, cast, and dyn_cast:
00163   static inline bool classof(const Instruction *) { return true; }
00164   static inline bool classof(const Value *V) {
00165     return V->getValueType() >= Value::InstructionVal;
00166   }
00167 
00168   //----------------------------------------------------------------------
00169   // Exported enumerations...
00170   //
00171   enum TermOps {       // These terminate basic blocks
00172 #define  FIRST_TERM_INST(N)             TermOpsBegin = N,
00173 #define HANDLE_TERM_INST(N, OPC, CLASS) OPC = N,
00174 #define   LAST_TERM_INST(N)             TermOpsEnd = N+1
00175 #include "llvm/Instruction.def"
00176   };
00177 
00178   enum BinaryOps {
00179 #define  FIRST_BINARY_INST(N)             BinaryOpsBegin = N,
00180 #define HANDLE_BINARY_INST(N, OPC, CLASS) OPC = N,
00181 #define   LAST_BINARY_INST(N)             BinaryOpsEnd = N+1
00182 #include "llvm/Instruction.def"
00183   };
00184 
00185   enum MemoryOps {
00186 #define  FIRST_MEMORY_INST(N)             MemoryOpsBegin = N,
00187 #define HANDLE_MEMORY_INST(N, OPC, CLASS) OPC = N,
00188 #define   LAST_MEMORY_INST(N)             MemoryOpsEnd = N+1
00189 #include "llvm/Instruction.def"
00190   };
00191 
00192   enum OtherOps {
00193 #define  FIRST_OTHER_INST(N)             OtherOpsBegin = N,
00194 #define HANDLE_OTHER_INST(N, OPC, CLASS) OPC = N,
00195 #define   LAST_OTHER_INST(N)             OtherOpsEnd = N+1
00196 #include "llvm/Instruction.def"
00197   };
00198 };
00199 
00200 } // End llvm namespace
00201 
00202 #endif