src/llvm/include/llvm/Instruction.h

   1 //===-- llvm/Instruction.h - Instruction class definition -------*- 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 contains the declaration of the Instruction class, which is the
  11 // base class for all of the LLVM instructions.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef LLVM_INSTRUCTION_H
  16 #define LLVM_INSTRUCTION_H
  17
  18 #include "llvm/User.h"
  19 #include "llvm/ADT/ilist_node.h"
  20 #include "llvm/Support/DebugLoc.h"
  21
  22 namespace llvm {
  23
  24 class LLVMContext;
  25 class MDNode;
  26
  27 template<typename ValueSubClass, typename ItemParentClass>
  28   class SymbolTableListTraits;
  29
  30 class Instruction : public User, public ilist_node<Instruction> {
  31   void operator=(const Instruction &) LLVM_DELETED_FUNCTION;
  32   Instruction(const Instruction &) LLVM_DELETED_FUNCTION;
  33
  34   BasicBlock *Parent;
  35   DebugLoc DbgLoc;                         // 'dbg' Metadata cache.
  36
  37   enum {
  38     /// HasMetadataBit - This is a bit stored in the SubClassData field which
  39     /// indicates whether this instruction has metadata attached to it or not.
  40     HasMetadataBit = 1 << 15
  41   };
  42 public:
  43   // Out of line virtual method, so the vtable, etc has a home.
  44   ~Instruction();
  45
  46   /// use_back - Specialize the methods defined in Value, as we know that an
  47   /// instruction can only be used by other instructions.
  48   Instruction       *use_back()       { return cast<Instruction>(*use_begin());}
  49   const Instruction *use_back() const { return cast<Instruction>(*use_begin());}
  50
  51   inline const BasicBlock *getParent() const { return Parent; }
  52   inline       BasicBlock *getParent()       { return Parent; }
  53
  54   /// removeFromParent - This method unlinks 'this' from the containing basic
  55   /// block, but does not delete it.
  56   ///
  57   void removeFromParent();
  58
  59   /// eraseFromParent - This method unlinks 'this' from the containing basic
  60   /// block and deletes it.
  61   ///
  62   void eraseFromParent();
  63
  64   /// insertBefore - Insert an unlinked instructions into a basic block
  65   /// immediately before the specified instruction.
  66   void insertBefore(Instruction *InsertPos);
  67
  68   /// insertAfter - Insert an unlinked instructions into a basic block
  69   /// immediately after the specified instruction.
  70   void insertAfter(Instruction *InsertPos);
  71
  72   /// moveBefore - Unlink this instruction from its current basic block and
  73   /// insert it into the basic block that MovePos lives in, right before
  74   /// MovePos.
  75   void moveBefore(Instruction *MovePos);
  76
  77   //===--------------------------------------------------------------------===//
  78   // Subclass classification.
  79   //===--------------------------------------------------------------------===//
  80
  81   /// getOpcode() returns a member of one of the enums like Instruction::Add.
  82   unsigned getOpcode() const { return getValueID() - InstructionVal; }
  83
  84   const char *getOpcodeName() const { return getOpcodeName(getOpcode()); }
  85   bool isTerminator() const { return isTerminator(getOpcode()); }
  86   bool isBinaryOp() const { return isBinaryOp(getOpcode()); }
  87   bool isShift() { return isShift(getOpcode()); }
  88   bool isCast() const { return isCast(getOpcode()); }
  89
  90   static const char* getOpcodeName(unsigned OpCode);
  91
  92   static inline bool isTerminator(unsigned OpCode) {
  93     return OpCode >= TermOpsBegin && OpCode < TermOpsEnd;
  94   }
  95
  96   static inline bool isBinaryOp(unsigned Opcode) {
  97     return Opcode >= BinaryOpsBegin && Opcode < BinaryOpsEnd;
  98   }
  99
 100   /// @brief Determine if the Opcode is one of the shift instructions.
 101   static inline bool isShift(unsigned Opcode) {
 102     return Opcode >= Shl && Opcode <= AShr;
 103   }
 104
 105   /// isLogicalShift - Return true if this is a logical shift left or a logical
 106   /// shift right.
 107   inline bool isLogicalShift() const {
 108     return getOpcode() == Shl || getOpcode() == LShr;
 109   }
 110
 111   /// isArithmeticShift - Return true if this is an arithmetic shift right.
 112   inline bool isArithmeticShift() const {
 113     return getOpcode() == AShr;
 114   }
 115
 116   /// @brief Determine if the OpCode is one of the CastInst instructions.
 117   static inline bool isCast(unsigned OpCode) {
 118     return OpCode >= CastOpsBegin && OpCode < CastOpsEnd;
 119   }
 120
 121   //===--------------------------------------------------------------------===//
 122   // Metadata manipulation.
 123   //===--------------------------------------------------------------------===//
 124
 125   /// hasMetadata() - Return true if this instruction has any metadata attached
 126   /// to it.
 127   bool hasMetadata() const {
 128     return !DbgLoc.isUnknown() || hasMetadataHashEntry();
 129   }
 130
 131   /// hasMetadataOtherThanDebugLoc - Return true if this instruction has
 132   /// metadata attached to it other than a debug location.
 133   bool hasMetadataOtherThanDebugLoc() const {
 134     return hasMetadataHashEntry();
 135   }
 136
 137   /// getMetadata - Get the metadata of given kind attached to this Instruction.
 138   /// If the metadata is not found then return null.
 139   MDNode *getMetadata(unsigned KindID) const {
 140     if (!hasMetadata()) return 0;
 141     return getMetadataImpl(KindID);
 142   }
 143
 144   /// getMetadata - Get the metadata of given kind attached to this Instruction.
 145   /// If the metadata is not found then return null.
 146   MDNode *getMetadata(StringRef Kind) const {
 147     if (!hasMetadata()) return 0;
 148     return getMetadataImpl(Kind);
 149   }
 150
 151   /// getAllMetadata - Get all metadata attached to this Instruction.  The first
 152   /// element of each pair returned is the KindID, the second element is the
 153   /// metadata value.  This list is returned sorted by the KindID.
 154   void getAllMetadata(SmallVectorImpl<std::pair<unsigned, MDNode*> > &MDs)const{
 155     if (hasMetadata())
 156       getAllMetadataImpl(MDs);
 157   }
 158
 159   /// getAllMetadataOtherThanDebugLoc - This does the same thing as
 160   /// getAllMetadata, except that it filters out the debug location.
 161   void getAllMetadataOtherThanDebugLoc(SmallVectorImpl<std::pair<unsigned,
 162                                        MDNode*> > &MDs) const {
 163     if (hasMetadataOtherThanDebugLoc())
 164       getAllMetadataOtherThanDebugLocImpl(MDs);
 165   }
 166
 167   /// setMetadata - Set the metadata of the specified kind to the specified
 168   /// node.  This updates/replaces metadata if already present, or removes it if
 169   /// Node is null.
 170   void setMetadata(unsigned KindID, MDNode *Node);
 171   void setMetadata(StringRef Kind, MDNode *Node);
 172
 173   /// setDebugLoc - Set the debug location information for this instruction.
 174   void setDebugLoc(const DebugLoc &Loc) { DbgLoc = Loc; }
 175
 176   /// getDebugLoc - Return the debug location for this node as a DebugLoc.
 177   const DebugLoc &getDebugLoc() const { return DbgLoc; }
 178
 179 private:
 180   /// hasMetadataHashEntry - Return true if we have an entry in the on-the-side
 181   /// metadata hash.
 182   bool hasMetadataHashEntry() const {
 183     return (getSubclassDataFromValue() & HasMetadataBit) != 0;
 184   }
 185
 186   // These are all implemented in Metadata.cpp.
 187   MDNode *getMetadataImpl(unsigned KindID) const;
 188   MDNode *getMetadataImpl(StringRef Kind) const;
 189   void getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned,MDNode*> > &)const;
 190   void getAllMetadataOtherThanDebugLocImpl(SmallVectorImpl<std::pair<unsigned,
 191                                            MDNode*> > &) const;
 192   void clearMetadataHashEntries();
 193 public:
 194   //===--------------------------------------------------------------------===//
 195   // Predicates and helper methods.
 196   //===--------------------------------------------------------------------===//
 197
 198
 199   /// isAssociative - Return true if the instruction is associative:
 200   ///
 201   ///   Associative operators satisfy:  x op (y op z) === (x op y) op z
 202   ///
 203   /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative.
 204   ///
 205   bool isAssociative() const { return isAssociative(getOpcode()); }
 206   static bool isAssociative(unsigned op);
 207
 208   /// isCommutative - Return true if the instruction is commutative:
 209   ///
 210   ///   Commutative operators satisfy: (x op y) === (y op x)
 211   ///
 212   /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
 213   /// applied to any type.
 214   ///
 215   bool isCommutative() const { return isCommutative(getOpcode()); }
 216   static bool isCommutative(unsigned op);
 217
 218   /// isIdempotent - Return true if the instruction is idempotent:
 219   ///
 220   ///   Idempotent operators satisfy:  x op x === x
 221   ///
 222   /// In LLVM, the And and Or operators are idempotent.
 223   ///
 224   bool isIdempotent() const { return isIdempotent(getOpcode()); }
 225   static bool isIdempotent(unsigned op);
 226
 227   /// isNilpotent - Return true if the instruction is nilpotent:
 228   ///
 229   ///   Nilpotent operators satisfy:  x op x === Id,
 230   ///
 231   ///   where Id is the identity for the operator, i.e. a constant such that
 232   ///     x op Id === x and Id op x === x for all x.
 233   ///
 234   /// In LLVM, the Xor operator is nilpotent.
 235   ///
 236   bool isNilpotent() const { return isNilpotent(getOpcode()); }
 237   static bool isNilpotent(unsigned op);
 238
 239   /// mayWriteToMemory - Return true if this instruction may modify memory.
 240   ///
 241   bool mayWriteToMemory() const;
 242
 243   /// mayReadFromMemory - Return true if this instruction may read memory.
 244   ///
 245   bool mayReadFromMemory() const;
 246
 247   /// mayReadOrWriteMemory - Return true if this instruction may read or
 248   /// write memory.
 249   ///
 250   bool mayReadOrWriteMemory() const {
 251     return mayReadFromMemory() || mayWriteToMemory();
 252   }
 253
 254   /// mayThrow - Return true if this instruction may throw an exception.
 255   ///
 256   bool mayThrow() const;
 257
 258   /// mayHaveSideEffects - Return true if the instruction may have side effects.
 259   ///
 260   /// Note that this does not consider malloc and alloca to have side
 261   /// effects because the newly allocated memory is completely invisible to
 262   /// instructions which don't used the returned value.  For cases where this
 263   /// matters, isSafeToSpeculativelyExecute may be more appropriate.
 264   bool mayHaveSideEffects() const {
 265     return mayWriteToMemory() || mayThrow();
 266   }
 267
 268   /// clone() - Create a copy of 'this' instruction that is identical in all
 269   /// ways except the following:
 270   ///   * The instruction has no parent
 271   ///   * The instruction has no name
 272   ///
 273   Instruction *clone() const;
 274
 275   /// isIdenticalTo - Return true if the specified instruction is exactly
 276   /// identical to the current one.  This means that all operands match and any
 277   /// extra information (e.g. load is volatile) agree.
 278   bool isIdenticalTo(const Instruction *I) const;
 279
 280   /// isIdenticalToWhenDefined - This is like isIdenticalTo, except that it
 281   /// ignores the SubclassOptionalData flags, which specify conditions
 282   /// under which the instruction's result is undefined.
 283   bool isIdenticalToWhenDefined(const Instruction *I) const;
 284
 285   /// When checking for operation equivalence (using isSameOperationAs) it is
 286   /// sometimes useful to ignore certain attributes.
 287   enum OperationEquivalenceFlags {
 288     /// Check for equivalence ignoring load/store alignment.
 289     CompareIgnoringAlignment = 1<<0,
 290     /// Check for equivalence treating a type and a vector of that type
 291     /// as equivalent.
 292     CompareUsingScalarTypes = 1<<1
 293   };
 294
 295   /// This function determines if the specified instruction executes the same
 296   /// operation as the current one. This means that the opcodes, type, operand
 297   /// types and any other factors affecting the operation must be the same. This
 298   /// is similar to isIdenticalTo except the operands themselves don't have to
 299   /// be identical.
 300   /// @returns true if the specified instruction is the same operation as
 301   /// the current one.
 302   /// @brief Determine if one instruction is the same operation as another.
 303   bool isSameOperationAs(const Instruction *I, unsigned flags = 0) const;
 304
 305   /// isUsedOutsideOfBlock - Return true if there are any uses of this
 306   /// instruction in blocks other than the specified block.  Note that PHI nodes
 307   /// are considered to evaluate their operands in the corresponding predecessor
 308   /// block.
 309   bool isUsedOutsideOfBlock(const BasicBlock *BB) const;
 310
 311
 312   /// Methods for support type inquiry through isa, cast, and dyn_cast:
 313   static inline bool classof(const Instruction *) { return true; }
 314   static inline bool classof(const Value *V) {
 315     return V->getValueID() >= Value::InstructionVal;
 316   }
 317
 318   //----------------------------------------------------------------------
 319   // Exported enumerations.
 320   //
 321   enum TermOps {       // These terminate basic blocks
 322 #define  FIRST_TERM_INST(N)             TermOpsBegin = N,
 323 #define HANDLE_TERM_INST(N, OPC, CLASS) OPC = N,
 324 #define   LAST_TERM_INST(N)             TermOpsEnd = N+1
 325 #include "llvm/Instruction.def"
 326   };
 327
 328   enum BinaryOps {
 329 #define  FIRST_BINARY_INST(N)             BinaryOpsBegin = N,
 330 #define HANDLE_BINARY_INST(N, OPC, CLASS) OPC = N,
 331 #define   LAST_BINARY_INST(N)             BinaryOpsEnd = N+1
 332 #include "llvm/Instruction.def"
 333   };
 334
 335   enum MemoryOps {
 336 #define  FIRST_MEMORY_INST(N)             MemoryOpsBegin = N,
 337 #define HANDLE_MEMORY_INST(N, OPC, CLASS) OPC = N,
 338 #define   LAST_MEMORY_INST(N)             MemoryOpsEnd = N+1
 339 #include "llvm/Instruction.def"
 340   };
 341
 342   enum CastOps {
 343 #define  FIRST_CAST_INST(N)             CastOpsBegin = N,
 344 #define HANDLE_CAST_INST(N, OPC, CLASS) OPC = N,
 345 #define   LAST_CAST_INST(N)             CastOpsEnd = N+1
 346 #include "llvm/Instruction.def"
 347   };
 348
 349   enum OtherOps {
 350 #define  FIRST_OTHER_INST(N)             OtherOpsBegin = N,
 351 #define HANDLE_OTHER_INST(N, OPC, CLASS) OPC = N,
 352 #define   LAST_OTHER_INST(N)             OtherOpsEnd = N+1
 353 #include "llvm/Instruction.def"
 354   };
 355 private:
 356   // Shadow Value::setValueSubclassData with a private forwarding method so that
 357   // subclasses cannot accidentally use it.
 358   void setValueSubclassData(unsigned short D) {
 359     Value::setValueSubclassData(D);
 360   }
 361   unsigned short getSubclassDataFromValue() const {
 362     return Value::getSubclassDataFromValue();
 363   }
 364
 365   void setHasMetadataHashEntry(bool V) {
 366     setValueSubclassData((getSubclassDataFromValue() & ~HasMetadataBit) |
 367                          (V ? HasMetadataBit : 0));
 368   }
 369
 370   friend class SymbolTableListTraits<Instruction, BasicBlock>;
 371   void setParent(BasicBlock *P);
 372 protected:
 373   // Instruction subclasses can stick up to 15 bits of stuff into the
 374   // SubclassData field of instruction with these members.
 375
 376   // Verify that only the low 15 bits are used.
 377   void setInstructionSubclassData(unsigned short D) {
 378     assert((D & HasMetadataBit) == 0 && "Out of range value put into field");
 379     setValueSubclassData((getSubclassDataFromValue() & HasMetadataBit) | D);
 380   }
 381
 382   unsigned getSubclassDataFromInstruction() const {
 383     return getSubclassDataFromValue() & ~HasMetadataBit;
 384   }
 385
 386   Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
 387               Instruction *InsertBefore = 0);
 388   Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
 389               BasicBlock *InsertAtEnd);
 390   virtual Instruction *clone_impl() const = 0;
 391
 392 };
 393
 394 // Instruction* is only 4-byte aligned.
 395 template<>
 396 class PointerLikeTypeTraits<Instruction*> {
 397   typedef Instruction* PT;
 398 public:
 399   static inline void *getAsVoidPointer(PT P) { return P; }
 400   static inline PT getFromVoidPointer(void *P) {
 401     return static_cast<PT>(P);
 402   }
 403   enum { NumLowBitsAvailable = 2 };
 404 };
 405
 406 } // End llvm namespace
 407
 408 #endif