LLVM API Documentation

Constants.h

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00001 //===-- llvm/Constants.h - Constant class subclass definitions --*- 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 declarations for the subclasses of Constant, which
00011 // represent the different flavors of constant values that live in LLVM.  Note
00012 // that Constants are immutable (once created they never change) and are fully
00013 // shared by structural equivalence.  This means that two structurally
00014 // equivalent constants will always have the same address.  Constant's are
00015 // created on demand as needed and never deleted: thus clients don't have to
00016 // worry about the lifetime of the objects.
00017 //
00018 //===----------------------------------------------------------------------===//
00019 
00020 #ifndef LLVM_CONSTANTS_H
00021 #define LLVM_CONSTANTS_H
00022 
00023 #include "llvm/Constant.h"
00024 #include "llvm/Type.h"
00025 
00026 namespace llvm {
00027 
00028 class ArrayType;
00029 class StructType;
00030 class PointerType;
00031 class PackedType;
00032 
00033 template<class ConstantClass, class TypeClass, class ValType>
00034 struct ConstantCreator;
00035 template<class ConstantClass, class TypeClass>
00036 struct ConvertConstantType;
00037 
00038 //===----------------------------------------------------------------------===//
00039 /// ConstantIntegral - Shared superclass of boolean and integer constants.
00040 ///
00041 /// This class just defines some common interfaces to be implemented.
00042 ///
00043 class ConstantIntegral : public Constant {
00044 protected:
00045   union {
00046     int64_t  Signed;
00047     uint64_t Unsigned;
00048   } Val;
00049   ConstantIntegral(const Type *Ty, ValueTy VT, uint64_t V);
00050 public:
00051 
00052   /// getRawValue - return the underlying value of this constant as a 64-bit
00053   /// unsigned integer value.
00054   ///
00055   inline uint64_t getRawValue() const { return Val.Unsigned; }
00056   
00057   /// getZExtValue - Return the constant zero extended as appropriate for this
00058   /// type.
00059   inline uint64_t getZExtValue() const {
00060     unsigned Size = getType()->getPrimitiveSizeInBits();
00061     return Val.Unsigned & (~uint64_t(0UL) >> (64-Size));
00062   }
00063 
00064   /// getSExtValue - Return the constant sign extended as appropriate for this
00065   /// type.
00066   inline int64_t getSExtValue() const {
00067     unsigned Size = getType()->getPrimitiveSizeInBits();
00068     return (Val.Signed << (64-Size)) >> (64-Size);
00069   }
00070   
00071   /// isNullValue - Return true if this is the value that would be returned by
00072   /// getNullValue.
00073   ///
00074   virtual bool isNullValue() const = 0;
00075 
00076   /// isMaxValue - Return true if this is the largest value that may be
00077   /// represented by this type.
00078   ///
00079   virtual bool isMaxValue() const = 0;
00080 
00081   /// isMinValue - Return true if this is the smallest value that may be
00082   /// represented by this type.
00083   ///
00084   virtual bool isMinValue() const = 0;
00085 
00086   /// isAllOnesValue - Return true if every bit in this constant is set to true.
00087   ///
00088   virtual bool isAllOnesValue() const = 0;
00089 
00090   /// Static constructor to get the maximum/minimum/allones constant of
00091   /// specified (integral) type...
00092   ///
00093   static ConstantIntegral *getMaxValue(const Type *Ty);
00094   static ConstantIntegral *getMinValue(const Type *Ty);
00095   static ConstantIntegral *getAllOnesValue(const Type *Ty);
00096 
00097   /// Methods for support type inquiry through isa, cast, and dyn_cast:
00098   static inline bool classof(const ConstantIntegral *) { return true; }
00099   static bool classof(const Value *V) {
00100     return V->getValueType() == ConstantBoolVal ||
00101            V->getValueType() == ConstantSIntVal ||
00102            V->getValueType() == ConstantUIntVal;
00103   }
00104 };
00105 
00106 
00107 //===----------------------------------------------------------------------===//
00108 /// ConstantBool - Boolean Values
00109 ///
00110 class ConstantBool : public ConstantIntegral {
00111   ConstantBool(bool V);
00112 public:
00113   static ConstantBool *True, *False;  // The True & False values
00114 
00115   /// get() - Static factory methods - Return objects of the specified value
00116   static ConstantBool *get(bool Value) { return Value ? True : False; }
00117   static ConstantBool *get(const Type *Ty, bool Value) { return get(Value); }
00118 
00119   /// inverted - Return the opposite value of the current value.
00120   inline ConstantBool *inverted() const { return (this==True) ? False : True; }
00121 
00122   /// getValue - return the boolean value of this constant.
00123   ///
00124   inline bool getValue() const { return static_cast<bool>(getRawValue()); }
00125 
00126   /// isNullValue - Return true if this is the value that would be returned by
00127   /// getNullValue.
00128   ///
00129   virtual bool isNullValue() const { return this == False; }
00130   virtual bool isMaxValue() const { return this == True; }
00131   virtual bool isMinValue() const { return this == False; }
00132   virtual bool isAllOnesValue() const { return this == True; }
00133 
00134   /// Methods for support type inquiry through isa, cast, and dyn_cast:
00135   static inline bool classof(const ConstantBool *) { return true; }
00136   static bool classof(const Value *V) {
00137     return V->getValueType() == ConstantBoolVal;
00138   }
00139 };
00140 
00141 
00142 //===----------------------------------------------------------------------===//
00143 /// ConstantInt - Superclass of ConstantSInt & ConstantUInt, to make dealing
00144 /// with integral constants easier.
00145 ///
00146 class ConstantInt : public ConstantIntegral {
00147 protected:
00148   ConstantInt(const ConstantInt &);      // DO NOT IMPLEMENT
00149   ConstantInt(const Type *Ty, ValueTy VT, uint64_t V);
00150 public:
00151   /// equalsInt - Provide a helper method that can be used to determine if the
00152   /// constant contained within is equal to a constant.  This only works for
00153   /// very small values, because this is all that can be represented with all
00154   /// types.
00155   ///
00156   bool equalsInt(unsigned char V) const {
00157     assert(V <= 127 &&
00158            "equalsInt: Can only be used with very small positive constants!");
00159     return Val.Unsigned == V;
00160   }
00161 
00162   /// ConstantInt::get static method: return a ConstantInt with the specified
00163   /// value.  as above, we work only with very small values here.
00164   ///
00165   static ConstantInt *get(const Type *Ty, unsigned char V);
00166 
00167   /// isNullValue - Return true if this is the value that would be returned by
00168   /// getNullValue.
00169   virtual bool isNullValue() const { return Val.Unsigned == 0; }
00170   virtual bool isMaxValue() const = 0;
00171   virtual bool isMinValue() const = 0;
00172 
00173   /// Methods for support type inquiry through isa, cast, and dyn_cast:
00174   static inline bool classof(const ConstantInt *) { return true; }
00175   static bool classof(const Value *V) {
00176     return V->getValueType() == ConstantSIntVal ||
00177            V->getValueType() == ConstantUIntVal;
00178   }
00179 };
00180 
00181 
00182 //===----------------------------------------------------------------------===//
00183 /// ConstantSInt - Signed Integer Values [sbyte, short, int, long]
00184 ///
00185 class ConstantSInt : public ConstantInt {
00186   ConstantSInt(const ConstantSInt &);      // DO NOT IMPLEMENT
00187   friend struct ConstantCreator<ConstantSInt, Type, int64_t>;
00188 
00189 protected:
00190   ConstantSInt(const Type *Ty, int64_t V);
00191 public:
00192   /// get() - Static factory methods - Return objects of the specified value
00193   ///
00194   static ConstantSInt *get(const Type *Ty, int64_t V);
00195 
00196   /// isValueValidForType - return true if Ty is big enough to represent V.
00197   ///
00198   static bool isValueValidForType(const Type *Ty, int64_t V);
00199 
00200   /// getValue - return the underlying value of this constant.
00201   ///
00202   inline int64_t getValue() const { return Val.Signed; }
00203 
00204   virtual bool isAllOnesValue() const { return getValue() == -1; }
00205 
00206   /// isMaxValue - Return true if this is the largest value that may be
00207   /// represented by this type.
00208   ///
00209   virtual bool isMaxValue() const {
00210     int64_t V = getValue();
00211     if (V < 0) return false;    // Be careful about wrap-around on 'long's
00212     ++V;
00213     return !isValueValidForType(getType(), V) || V < 0;
00214   }
00215 
00216   /// isMinValue - Return true if this is the smallest value that may be
00217   /// represented by this type.
00218   ///
00219   virtual bool isMinValue() const {
00220     int64_t V = getValue();
00221     if (V > 0) return false;    // Be careful about wrap-around on 'long's
00222     --V;
00223     return !isValueValidForType(getType(), V) || V > 0;
00224   }
00225 
00226   /// Methods for support type inquiry through isa, cast, and dyn_cast:
00227   ///
00228   static inline bool classof(const ConstantSInt *) { return true; }
00229   static bool classof(const Value *V) {
00230     return V->getValueType() == ConstantSIntVal;
00231   }
00232 };
00233 
00234 //===----------------------------------------------------------------------===//
00235 /// ConstantUInt - Unsigned Integer Values [ubyte, ushort, uint, ulong]
00236 ///
00237 class ConstantUInt : public ConstantInt {
00238   ConstantUInt(const ConstantUInt &);      // DO NOT IMPLEMENT
00239   friend struct ConstantCreator<ConstantUInt, Type, uint64_t>;
00240 protected:
00241   ConstantUInt(const Type *Ty, uint64_t V);
00242 public:
00243   /// get() - Static factory methods - Return objects of the specified value
00244   ///
00245   static ConstantUInt *get(const Type *Ty, uint64_t V);
00246 
00247   /// isValueValidForType - return true if Ty is big enough to represent V.
00248   ///
00249   static bool isValueValidForType(const Type *Ty, uint64_t V);
00250 
00251   /// getValue - return the underlying value of this constant.
00252   ///
00253   inline uint64_t getValue() const { return Val.Unsigned; }
00254 
00255   /// isMaxValue - Return true if this is the largest value that may be
00256   /// represented by this type.
00257   ///
00258   virtual bool isAllOnesValue() const;
00259   virtual bool isMaxValue() const { return isAllOnesValue(); }
00260   virtual bool isMinValue() const { return getValue() == 0; }
00261 
00262   /// Methods for support type inquiry through isa, cast, and dyn_cast:
00263   static inline bool classof(const ConstantUInt *) { return true; }
00264   static bool classof(const Value *V) {
00265     return V->getValueType() == ConstantUIntVal;
00266   }
00267 };
00268 
00269 
00270 //===----------------------------------------------------------------------===//
00271 /// ConstantFP - Floating Point Values [float, double]
00272 ///
00273 class ConstantFP : public Constant {
00274   double Val;
00275   friend struct ConstantCreator<ConstantFP, Type, uint64_t>;
00276   friend struct ConstantCreator<ConstantFP, Type, uint32_t>;
00277   ConstantFP(const ConstantFP &);      // DO NOT IMPLEMENT
00278 protected:
00279   ConstantFP(const Type *Ty, double V);
00280 public:
00281   /// get() - Static factory methods - Return objects of the specified value
00282   static ConstantFP *get(const Type *Ty, double V);
00283 
00284   /// isValueValidForType - return true if Ty is big enough to represent V.
00285   static bool isValueValidForType(const Type *Ty, double V);
00286   inline double getValue() const { return Val; }
00287 
00288   /// isNullValue - Return true if this is the value that would be returned by
00289   /// getNullValue.  Don't depend on == for doubles to tell us it's zero, it
00290   /// considers -0.0 to be null as well as 0.0.  :(
00291   virtual bool isNullValue() const;
00292 
00293   /// isExactlyValue - We don't rely on operator== working on double values, as
00294   /// it returns true for things that are clearly not equal, like -0.0 and 0.0.
00295   /// As such, this method can be used to do an exact bit-for-bit comparison of
00296   /// two floating point values.
00297   bool isExactlyValue(double V) const;
00298 
00299   /// Methods for support type inquiry through isa, cast, and dyn_cast:
00300   static inline bool classof(const ConstantFP *) { return true; }
00301   static bool classof(const Value *V) {
00302     return V->getValueType() == ConstantFPVal;
00303   }
00304 };
00305 
00306 //===----------------------------------------------------------------------===//
00307 /// ConstantAggregateZero - All zero aggregate value
00308 ///
00309 class ConstantAggregateZero : public Constant {
00310   friend struct ConstantCreator<ConstantAggregateZero, Type, char>;
00311   ConstantAggregateZero(const ConstantAggregateZero &);      // DO NOT IMPLEMENT
00312 protected:
00313   ConstantAggregateZero(const Type *Ty)
00314     : Constant(Ty, ConstantAggregateZeroVal, 0, 0) {}
00315 public:
00316   /// get() - static factory method for creating a null aggregate.  It is
00317   /// illegal to call this method with a non-aggregate type.
00318   static Constant *get(const Type *Ty);
00319 
00320   /// isNullValue - Return true if this is the value that would be returned by
00321   /// getNullValue.
00322   virtual bool isNullValue() const { return true; }
00323 
00324   virtual void destroyConstant();
00325 
00326   /// Methods for support type inquiry through isa, cast, and dyn_cast:
00327   ///
00328   static bool classof(const ConstantAggregateZero *) { return true; }
00329   static bool classof(const Value *V) {
00330     return V->getValueType() == ConstantAggregateZeroVal;
00331   }
00332 };
00333 
00334 
00335 //===----------------------------------------------------------------------===//
00336 /// ConstantArray - Constant Array Declarations
00337 ///
00338 class ConstantArray : public Constant {
00339   friend struct ConstantCreator<ConstantArray, ArrayType,
00340                                     std::vector<Constant*> >;
00341   ConstantArray(const ConstantArray &);      // DO NOT IMPLEMENT
00342 protected:
00343   ConstantArray(const ArrayType *T, const std::vector<Constant*> &Val);
00344   ~ConstantArray();
00345 public:
00346   /// get() - Static factory methods - Return objects of the specified value
00347   static Constant *get(const ArrayType *T, const std::vector<Constant*> &);
00348 
00349   /// This method constructs a ConstantArray and initializes it with a text
00350   /// string. The default behavior (AddNull==true) causes a null terminator to
00351   /// be placed at the end of the array. This effectively increases the length
00352   /// of the array by one (you've been warned).  However, in some situations 
00353   /// this is not desired so if AddNull==false then the string is copied without
00354   /// null termination. 
00355   static Constant *get(const std::string &Initializer, bool AddNull = true);
00356 
00357   /// getType - Specialize the getType() method to always return an ArrayType,
00358   /// which reduces the amount of casting needed in parts of the compiler.
00359   ///
00360   inline const ArrayType *getType() const {
00361     return reinterpret_cast<const ArrayType*>(Value::getType());
00362   }
00363 
00364   /// isString - This method returns true if the array is an array of sbyte or
00365   /// ubyte, and if the elements of the array are all ConstantInt's.
00366   bool isString() const;
00367 
00368   /// getAsString - If this array is isString(), then this method converts the
00369   /// array to an std::string and returns it.  Otherwise, it asserts out.
00370   ///
00371   std::string getAsString() const;
00372 
00373   /// isNullValue - Return true if this is the value that would be returned by
00374   /// getNullValue.  This always returns false because zero arrays are always
00375   /// created as ConstantAggregateZero objects.
00376   virtual bool isNullValue() const { return false; }
00377 
00378   virtual void destroyConstant();
00379   virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
00380 
00381   /// Methods for support type inquiry through isa, cast, and dyn_cast:
00382   static inline bool classof(const ConstantArray *) { return true; }
00383   static bool classof(const Value *V) {
00384     return V->getValueType() == ConstantArrayVal;
00385   }
00386 };
00387 
00388 
00389 //===----------------------------------------------------------------------===//
00390 // ConstantStruct - Constant Struct Declarations
00391 //
00392 class ConstantStruct : public Constant {
00393   friend struct ConstantCreator<ConstantStruct, StructType,
00394                                     std::vector<Constant*> >;
00395   ConstantStruct(const ConstantStruct &);      // DO NOT IMPLEMENT
00396 protected:
00397   ConstantStruct(const StructType *T, const std::vector<Constant*> &Val);
00398   ~ConstantStruct();
00399 public:
00400   /// get() - Static factory methods - Return objects of the specified value
00401   ///
00402   static Constant *get(const StructType *T, const std::vector<Constant*> &V);
00403   static Constant *get(const std::vector<Constant*> &V);
00404 
00405   /// getType() specialization - Reduce amount of casting...
00406   ///
00407   inline const StructType *getType() const {
00408     return reinterpret_cast<const StructType*>(Value::getType());
00409   }
00410 
00411   /// isNullValue - Return true if this is the value that would be returned by
00412   /// getNullValue.  This always returns false because zero structs are always
00413   /// created as ConstantAggregateZero objects.
00414   virtual bool isNullValue() const {
00415     return false;
00416   }
00417 
00418   virtual void destroyConstant();
00419   virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
00420 
00421   /// Methods for support type inquiry through isa, cast, and dyn_cast:
00422   static inline bool classof(const ConstantStruct *) { return true; }
00423   static bool classof(const Value *V) {
00424     return V->getValueType() == ConstantStructVal;
00425   }
00426 };
00427 
00428 //===----------------------------------------------------------------------===//
00429 /// ConstantPacked - Constant Packed Declarations
00430 ///
00431 class ConstantPacked : public Constant {
00432   friend struct ConstantCreator<ConstantPacked, PackedType,
00433                                     std::vector<Constant*> >;
00434   ConstantPacked(const ConstantPacked &);      // DO NOT IMPLEMENT
00435 protected:
00436   ConstantPacked(const PackedType *T, const std::vector<Constant*> &Val);
00437   ~ConstantPacked();
00438 public:
00439   /// get() - Static factory methods - Return objects of the specified value
00440   static Constant *get(const PackedType *T, const std::vector<Constant*> &);
00441   static Constant *get(const std::vector<Constant*> &V);
00442 
00443   /// getType - Specialize the getType() method to always return an PackedType,
00444   /// which reduces the amount of casting needed in parts of the compiler.
00445   ///
00446   inline const PackedType *getType() const {
00447     return reinterpret_cast<const PackedType*>(Value::getType());
00448   }
00449 
00450   /// isNullValue - Return true if this is the value that would be returned by
00451   /// getNullValue.  This always returns false because zero arrays are always
00452   /// created as ConstantAggregateZero objects.
00453   virtual bool isNullValue() const { return false; }
00454 
00455   virtual void destroyConstant();
00456   virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
00457 
00458   /// Methods for support type inquiry through isa, cast, and dyn_cast:
00459   static inline bool classof(const ConstantPacked *) { return true; }
00460   static bool classof(const Value *V) {
00461     return V->getValueType() == ConstantPackedVal;
00462   }
00463 };
00464 
00465 //===----------------------------------------------------------------------===//
00466 /// ConstantPointerNull - a constant pointer value that points to null
00467 ///
00468 class ConstantPointerNull : public Constant {
00469   friend struct ConstantCreator<ConstantPointerNull, PointerType, char>;
00470   ConstantPointerNull(const ConstantPointerNull &);      // DO NOT IMPLEMENT
00471 protected:
00472   ConstantPointerNull(const PointerType *T)
00473     : Constant(reinterpret_cast<const Type*>(T),
00474                Value::ConstantPointerNullVal, 0, 0) {}
00475 
00476 public:
00477 
00478   /// get() - Static factory methods - Return objects of the specified value
00479   static ConstantPointerNull *get(const PointerType *T);
00480 
00481   /// isNullValue - Return true if this is the value that would be returned by
00482   /// getNullValue.
00483   virtual bool isNullValue() const { return true; }
00484 
00485   virtual void destroyConstant();
00486 
00487   /// getType - Specialize the getType() method to always return an PointerType,
00488   /// which reduces the amount of casting needed in parts of the compiler.
00489   ///
00490   inline const PointerType *getType() const {
00491     return reinterpret_cast<const PointerType*>(Value::getType());
00492   }
00493 
00494   /// Methods for support type inquiry through isa, cast, and dyn_cast:
00495   static inline bool classof(const ConstantPointerNull *) { return true; }
00496   static bool classof(const Value *V) {
00497     return V->getValueType() == ConstantPointerNullVal;
00498   }
00499 };
00500 
00501 
00502 /// ConstantExpr - a constant value that is initialized with an expression using
00503 /// other constant values.
00504 ///
00505 /// This class uses the standard Instruction opcodes to define the various
00506 /// constant expressions.  The Opcode field for the ConstantExpr class is
00507 /// maintained in the Value::SubclassData field.
00508 class ConstantExpr : public Constant {
00509   friend struct ConstantCreator<ConstantExpr,Type,
00510                             std::pair<unsigned, std::vector<Constant*> > >;
00511   friend struct ConvertConstantType<ConstantExpr, Type>;
00512 
00513 protected:
00514   ConstantExpr(const Type *Ty, unsigned Opcode, Use *Ops, unsigned NumOps)
00515     : Constant(Ty, ConstantExprVal, Ops, NumOps) {
00516     // Operation type (an Instruction opcode) is stored as the SubclassData.
00517     SubclassData = Opcode;
00518   }
00519 
00520   // These private methods are used by the type resolution code to create
00521   // ConstantExprs in intermediate forms.
00522   static Constant *getTy(const Type *Ty, unsigned Opcode,
00523                          Constant *C1, Constant *C2);
00524   static Constant *getShiftTy(const Type *Ty,
00525                               unsigned Opcode, Constant *C1, Constant *C2);
00526   static Constant *getSelectTy(const Type *Ty,
00527                                Constant *C1, Constant *C2, Constant *C3);
00528   static Constant *getGetElementPtrTy(const Type *Ty, Constant *C,
00529                                       const std::vector<Value*> &IdxList);
00530   static Constant *getExtractElementTy(const Type *Ty, Constant *Val,
00531                                        Constant *Idx);
00532   static Constant *getInsertElementTy(const Type *Ty, Constant *Val,
00533                                       Constant *Elt, Constant *Idx);
00534   static Constant *getShuffleVectorTy(const Type *Ty, Constant *V1,
00535                                       Constant *V2, Constant *Mask);
00536 
00537 public:
00538   // Static methods to construct a ConstantExpr of different kinds.  Note that
00539   // these methods may return a object that is not an instance of the
00540   // ConstantExpr class, because they will attempt to fold the constant
00541   // expression into something simpler if possible.
00542 
00543   /// Cast constant expr
00544   ///
00545   static Constant *getCast(Constant *C, const Type *Ty);
00546   static Constant *getSignExtend(Constant *C, const Type *Ty);
00547   static Constant *getZeroExtend(Constant *C, const Type *Ty);
00548 
00549   /// Select constant expr
00550   ///
00551   static Constant *getSelect(Constant *C, Constant *V1, Constant *V2) {
00552     return getSelectTy(V1->getType(), C, V1, V2);
00553   }
00554 
00555   /// getSizeOf constant expr - computes the size of a type in a target
00556   /// independent way (Note: the return type is ULong but the object is not
00557   /// necessarily a ConstantUInt).
00558   ///
00559   static Constant *getSizeOf(const Type *Ty);
00560 
00561   /// getPtrPtrFromArrayPtr constant expr - given a pointer to a constant array,
00562   /// return a pointer to a pointer of the array element type.
00563   static Constant *getPtrPtrFromArrayPtr(Constant *C);
00564 
00565   /// ConstantExpr::get - Return a binary or shift operator constant expression,
00566   /// folding if possible.
00567   ///
00568   static Constant *get(unsigned Opcode, Constant *C1, Constant *C2);
00569 
00570   /// ConstantExpr::get* - Return some common constants without having to
00571   /// specify the full Instruction::OPCODE identifier.
00572   ///
00573   static Constant *getNeg(Constant *C);
00574   static Constant *getNot(Constant *C);
00575   static Constant *getAdd(Constant *C1, Constant *C2);
00576   static Constant *getSub(Constant *C1, Constant *C2);
00577   static Constant *getMul(Constant *C1, Constant *C2);
00578   static Constant *getDiv(Constant *C1, Constant *C2);
00579   static Constant *getRem(Constant *C1, Constant *C2);
00580   static Constant *getAnd(Constant *C1, Constant *C2);
00581   static Constant *getOr(Constant *C1, Constant *C2);
00582   static Constant *getXor(Constant *C1, Constant *C2);
00583   static Constant *getSetEQ(Constant *C1, Constant *C2);
00584   static Constant *getSetNE(Constant *C1, Constant *C2);
00585   static Constant *getSetLT(Constant *C1, Constant *C2);
00586   static Constant *getSetGT(Constant *C1, Constant *C2);
00587   static Constant *getSetLE(Constant *C1, Constant *C2);
00588   static Constant *getSetGE(Constant *C1, Constant *C2);
00589   static Constant *getShl(Constant *C1, Constant *C2);
00590   static Constant *getShr(Constant *C1, Constant *C2);
00591 
00592   static Constant *getUShr(Constant *C1, Constant *C2); // unsigned shr
00593   static Constant *getSShr(Constant *C1, Constant *C2); // signed shr
00594 
00595   /// Getelementptr form.  std::vector<Value*> is only accepted for convenience:
00596   /// all elements must be Constant's.
00597   ///
00598   static Constant *getGetElementPtr(Constant *C,
00599                                     const std::vector<Constant*> &IdxList);
00600   static Constant *getGetElementPtr(Constant *C,
00601                                     const std::vector<Value*> &IdxList);
00602 
00603   static Constant *getExtractElement(Constant *Vec, Constant *Idx);
00604   static Constant *getInsertElement(Constant *Vec, Constant *Elt,Constant *Idx);
00605   static Constant *getShuffleVector(Constant *V1, Constant *V2, Constant *Mask);
00606   
00607   /// isNullValue - Return true if this is the value that would be returned by
00608   /// getNullValue.
00609   virtual bool isNullValue() const { return false; }
00610 
00611   /// getOpcode - Return the opcode at the root of this constant expression
00612   unsigned getOpcode() const { return SubclassData; }
00613 
00614   /// getOpcodeName - Return a string representation for an opcode.
00615   const char *getOpcodeName() const;
00616 
00617   /// getWithOperandReplaced - Return a constant expression identical to this
00618   /// one, but with the specified operand set to the specified value.
00619   Constant *getWithOperandReplaced(unsigned OpNo, Constant *Op) const;
00620   
00621   /// getWithOperands - This returns the current constant expression with the
00622   /// operands replaced with the specified values.  The specified operands must
00623   /// match count and type with the existing ones.
00624   Constant *getWithOperands(const std::vector<Constant*> &Ops) const;
00625   
00626   virtual void destroyConstant();
00627   virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
00628 
00629   /// Override methods to provide more type information...
00630   inline Constant *getOperand(unsigned i) {
00631     return cast<Constant>(User::getOperand(i));
00632   }
00633   inline Constant *getOperand(unsigned i) const {
00634     return const_cast<Constant*>(cast<Constant>(User::getOperand(i)));
00635   }
00636 
00637 
00638   /// Methods for support type inquiry through isa, cast, and dyn_cast:
00639   static inline bool classof(const ConstantExpr *) { return true; }
00640   static inline bool classof(const Value *V) {
00641     return V->getValueType() == ConstantExprVal;
00642   }
00643 };
00644 
00645 
00646 //===----------------------------------------------------------------------===//
00647 /// UndefValue - 'undef' values are things that do not have specified contents.
00648 /// These are used for a variety of purposes, including global variable
00649 /// initializers and operands to instructions.  'undef' values can occur with
00650 /// any type.
00651 ///
00652 class UndefValue : public Constant {
00653   friend struct ConstantCreator<UndefValue, Type, char>;
00654   UndefValue(const UndefValue &);      // DO NOT IMPLEMENT
00655 protected:
00656   UndefValue(const Type *T) : Constant(T, UndefValueVal, 0, 0) {}
00657 public:
00658   /// get() - Static factory methods - Return an 'undef' object of the specified
00659   /// type.
00660   ///
00661   static UndefValue *get(const Type *T);
00662 
00663   /// isNullValue - Return true if this is the value that would be returned by
00664   /// getNullValue.
00665   virtual bool isNullValue() const { return false; }
00666 
00667   virtual void destroyConstant();
00668 
00669   /// Methods for support type inquiry through isa, cast, and dyn_cast:
00670   static inline bool classof(const UndefValue *) { return true; }
00671   static bool classof(const Value *V) {
00672     return V->getValueType() == UndefValueVal;
00673   }
00674 };
00675 
00676 } // End llvm namespace
00677 
00678 #endif