Constants.h revision 37eeaa729bc70258166a675ee00bbe95e608d519
1//===-- llvm/Constants.h - Constant class subclass definitions --*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file was developed by the LLVM research group and is distributed under 6// the University of Illinois Open Source License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10/// @file This file contains the declarations for the subclasses of Constant, 11/// which represent the different flavors of constant values that live in LLVM. 12/// Note that Constants are immutable (once created they never change) and are 13/// fully shared by structural equivalence. This means that two structurally 14/// equivalent constants will always have the same address. Constant's are 15/// created on demand as needed and never deleted: thus clients don't have to 16/// worry about the lifetime of the objects. 17// 18//===----------------------------------------------------------------------===// 19 20#ifndef LLVM_CONSTANTS_H 21#define LLVM_CONSTANTS_H 22 23#include "llvm/Constant.h" 24#include "llvm/Type.h" 25#include "llvm/ADT/APInt.h" 26 27namespace llvm { 28 29class ArrayType; 30class StructType; 31class PointerType; 32class VectorType; 33 34template<class ConstantClass, class TypeClass, class ValType> 35struct ConstantCreator; 36template<class ConstantClass, class TypeClass> 37struct ConvertConstantType; 38 39//===----------------------------------------------------------------------===// 40/// This is the shared class of boolean and integer constants. This class 41/// represents both boolean and integral constants. 42/// @brief Class for constant integers. 43class ConstantInt : public Constant { 44 static ConstantInt *TheTrueVal, *TheFalseVal; 45 ConstantInt(const ConstantInt &); // DO NOT IMPLEMENT 46 ConstantInt(const IntegerType *Ty, const APInt& V); 47 APInt Val; 48public: 49 /// Return the constant as an APInt value reference. This allows clients to 50 /// obtain a copy of the value, with all its precision in tact. 51 /// @brief Return the constant's value. 52 inline const APInt& getValue() const { 53 return Val; 54 } 55 56 /// Return the constant as a 64-bit unsigned integer value after it 57 /// has been zero extended as appropriate for the type of this constant. Note 58 /// that this method can assert if the value does not fit in 64 bits. 59 /// @deprecated 60 /// @brief Return the zero extended value. 61 inline uint64_t getZExtValue() const { 62 return Val.getZExtValue(); 63 } 64 65 /// Return the constant as a 64-bit integer value after it has been sign 66 /// sign extended as appropriate for the type of this constant. Note that 67 /// this method can assert if the value does not fit in 64 bits. 68 /// @deprecated 69 /// @brief Return the sign extended value. 70 inline int64_t getSExtValue() const { 71 return Val.getSExtValue(); 72 } 73 74 /// A helper method that can be used to determine if the constant contained 75 /// within is equal to a constant. This only works for very small values, 76 /// because this is all that can be represented with all types. 77 /// @brief Determine if this constant's value is same as an unsigned char. 78 bool equalsInt(uint64_t V) const { 79 return Val == V; 80 } 81 82 /// getTrue/getFalse - Return the singleton true/false values. 83 static inline ConstantInt *getTrue() { 84 if (TheTrueVal) return TheTrueVal; 85 return CreateTrueFalseVals(true); 86 } 87 static inline ConstantInt *getFalse() { 88 if (TheFalseVal) return TheFalseVal; 89 return CreateTrueFalseVals(false); 90 } 91 92 /// Return a ConstantInt with the specified value for the specified type. The 93 /// value V will be canonicalized to a an unsigned APInt. Accessing it with 94 /// either getSExtValue() or getZExtValue() will yield a correctly sized and 95 /// signed value for the type Ty. 96 /// @brief Get a ConstantInt for a specific value. 97 static ConstantInt *get(const Type *Ty, uint64_t V); 98 99 /// Return a ConstantInt with the specified value and an implied Type. The 100 /// type is the integer type that corresponds to the bit width of the value. 101 static ConstantInt *get(const APInt &V); 102 103 /// getType - Specialize the getType() method to always return an IntegerType, 104 /// which reduces the amount of casting needed in parts of the compiler. 105 /// 106 inline const IntegerType *getType() const { 107 return reinterpret_cast<const IntegerType*>(Value::getType()); 108 } 109 110 /// This static method returns true if the type Ty is big enough to 111 /// represent the value V. This can be used to avoid having the get method 112 /// assert when V is larger than Ty can represent. Note that there are two 113 /// versions of this method, one for unsigned and one for signed integers. 114 /// Although ConstantInt canonicalizes everything to an unsigned integer, 115 /// the signed version avoids callers having to convert a signed quantity 116 /// to the appropriate unsigned type before calling the method. 117 /// @returns true if V is a valid value for type Ty 118 /// @brief Determine if the value is in range for the given type. 119 static bool isValueValidForType(const Type *Ty, uint64_t V); 120 static bool isValueValidForType(const Type *Ty, int64_t V); 121 122 /// This function will return true iff this constant represents the "null" 123 /// value that would be returned by the getNullValue method. 124 /// @returns true if this is the null integer value. 125 /// @brief Determine if the value is null. 126 virtual bool isNullValue() const { 127 return Val == 0; 128 } 129 130 /// This is just a convenience method to make client code smaller for a 131 /// common case. 132 /// @brief Determine if the value is one. 133 virtual bool isUnitValue() const { 134 return Val == 1; 135 } 136 137 /// This function will return true iff every bit in this constant is set 138 /// to true. 139 /// @returns true iff this constant's bits are all set to true. 140 /// @brief Determine if the value is all ones. 141 bool isAllOnesValue() const { 142 return Val.isAllOnesValue(); 143 } 144 145 /// This function will return true iff this constant represents the largest 146 /// value that may be represented by the constant's type. 147 /// @returns true iff this is the largest value that may be represented 148 /// by this type. 149 /// @brief Determine if the value is maximal. 150 bool isMaxValue(bool isSigned) const { 151 if (isSigned) 152 return Val.isMaxSignedValue(); 153 else 154 return Val.isMaxValue(); 155 } 156 157 /// This function will return true iff this constant represents the smallest 158 /// value that may be represented by this constant's type. 159 /// @returns true if this is the smallest value that may be represented by 160 /// this type. 161 /// @brief Determine if the value is minimal. 162 bool isMinValue(bool isSigned) const { 163 if (isSigned) 164 return Val.isMinSignedValue(); 165 else 166 return Val.isMinValue(); 167 } 168 169 /// @returns the value for an integer constant of the given type that has all 170 /// its bits set to true. 171 /// @brief Get the all ones value 172 static ConstantInt *getAllOnesValue(const Type *Ty); 173 174 /// @brief Methods to support type inquiry through isa, cast, and dyn_cast. 175 static inline bool classof(const ConstantInt *) { return true; } 176 static bool classof(const Value *V) { 177 return V->getValueType() == ConstantIntVal; 178 } 179 static void ResetTrueFalse() { TheTrueVal = TheFalseVal = 0; } 180private: 181 static ConstantInt *CreateTrueFalseVals(bool WhichOne); 182}; 183 184 185//===----------------------------------------------------------------------===// 186/// ConstantFP - Floating Point Values [float, double] 187/// 188class ConstantFP : public Constant { 189 double Val; 190 ConstantFP(const ConstantFP &); // DO NOT IMPLEMENT 191protected: 192 ConstantFP(const Type *Ty, double V); 193public: 194 /// get() - Static factory methods - Return objects of the specified value 195 static ConstantFP *get(const Type *Ty, double V); 196 197 /// isValueValidForType - return true if Ty is big enough to represent V. 198 static bool isValueValidForType(const Type *Ty, double V); 199 inline double getValue() const { return Val; } 200 201 /// isNullValue - Return true if this is the value that would be returned by 202 /// getNullValue. Don't depend on == for doubles to tell us it's zero, it 203 /// considers -0.0 to be null as well as 0.0. :( 204 virtual bool isNullValue() const; 205 206 /// isExactlyValue - We don't rely on operator== working on double values, as 207 /// it returns true for things that are clearly not equal, like -0.0 and 0.0. 208 /// As such, this method can be used to do an exact bit-for-bit comparison of 209 /// two floating point values. 210 bool isExactlyValue(double V) const; 211 212 /// Methods for support type inquiry through isa, cast, and dyn_cast: 213 static inline bool classof(const ConstantFP *) { return true; } 214 static bool classof(const Value *V) { 215 return V->getValueType() == ConstantFPVal; 216 } 217}; 218 219//===----------------------------------------------------------------------===// 220/// ConstantAggregateZero - All zero aggregate value 221/// 222class ConstantAggregateZero : public Constant { 223 friend struct ConstantCreator<ConstantAggregateZero, Type, char>; 224 ConstantAggregateZero(const ConstantAggregateZero &); // DO NOT IMPLEMENT 225protected: 226 ConstantAggregateZero(const Type *Ty) 227 : Constant(Ty, ConstantAggregateZeroVal, 0, 0) {} 228public: 229 /// get() - static factory method for creating a null aggregate. It is 230 /// illegal to call this method with a non-aggregate type. 231 static Constant *get(const Type *Ty); 232 233 /// isNullValue - Return true if this is the value that would be returned by 234 /// getNullValue. 235 virtual bool isNullValue() const { return true; } 236 237 virtual void destroyConstant(); 238 239 /// Methods for support type inquiry through isa, cast, and dyn_cast: 240 /// 241 static bool classof(const ConstantAggregateZero *) { return true; } 242 static bool classof(const Value *V) { 243 return V->getValueType() == ConstantAggregateZeroVal; 244 } 245}; 246 247 248//===----------------------------------------------------------------------===// 249/// ConstantArray - Constant Array Declarations 250/// 251class ConstantArray : public Constant { 252 friend struct ConstantCreator<ConstantArray, ArrayType, 253 std::vector<Constant*> >; 254 ConstantArray(const ConstantArray &); // DO NOT IMPLEMENT 255protected: 256 ConstantArray(const ArrayType *T, const std::vector<Constant*> &Val); 257 ~ConstantArray(); 258public: 259 /// get() - Static factory methods - Return objects of the specified value 260 static Constant *get(const ArrayType *T, const std::vector<Constant*> &); 261 static Constant *get(const ArrayType *T, 262 Constant*const*Vals, unsigned NumVals) { 263 // FIXME: make this the primary ctor method. 264 return get(T, std::vector<Constant*>(Vals, Vals+NumVals)); 265 } 266 267 /// This method constructs a ConstantArray and initializes it with a text 268 /// string. The default behavior (AddNull==true) causes a null terminator to 269 /// be placed at the end of the array. This effectively increases the length 270 /// of the array by one (you've been warned). However, in some situations 271 /// this is not desired so if AddNull==false then the string is copied without 272 /// null termination. 273 static Constant *get(const std::string &Initializer, bool AddNull = true); 274 275 /// getType - Specialize the getType() method to always return an ArrayType, 276 /// which reduces the amount of casting needed in parts of the compiler. 277 /// 278 inline const ArrayType *getType() const { 279 return reinterpret_cast<const ArrayType*>(Value::getType()); 280 } 281 282 /// isString - This method returns true if the array is an array of sbyte or 283 /// ubyte, and if the elements of the array are all ConstantInt's. 284 bool isString() const; 285 286 /// isCString - This method returns true if the array is a string (see 287 /// isString) and it ends in a null byte \0 and does not contains any other 288 /// null bytes except its terminator. 289 bool isCString() const; 290 291 /// getAsString - If this array is isString(), then this method converts the 292 /// array to an std::string and returns it. Otherwise, it asserts out. 293 /// 294 std::string getAsString() const; 295 296 /// isNullValue - Return true if this is the value that would be returned by 297 /// getNullValue. This always returns false because zero arrays are always 298 /// created as ConstantAggregateZero objects. 299 virtual bool isNullValue() const { return false; } 300 301 virtual void destroyConstant(); 302 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U); 303 304 /// Methods for support type inquiry through isa, cast, and dyn_cast: 305 static inline bool classof(const ConstantArray *) { return true; } 306 static bool classof(const Value *V) { 307 return V->getValueType() == ConstantArrayVal; 308 } 309}; 310 311 312//===----------------------------------------------------------------------===// 313// ConstantStruct - Constant Struct Declarations 314// 315class ConstantStruct : public Constant { 316 friend struct ConstantCreator<ConstantStruct, StructType, 317 std::vector<Constant*> >; 318 ConstantStruct(const ConstantStruct &); // DO NOT IMPLEMENT 319protected: 320 ConstantStruct(const StructType *T, const std::vector<Constant*> &Val); 321 ~ConstantStruct(); 322public: 323 /// get() - Static factory methods - Return objects of the specified value 324 /// 325 static Constant *get(const StructType *T, const std::vector<Constant*> &V); 326 static Constant *get(const std::vector<Constant*> &V, bool Packed = false); 327 static Constant *get(Constant*const* Vals, unsigned NumVals, 328 bool Packed = false) { 329 // FIXME: make this the primary ctor method. 330 return get(std::vector<Constant*>(Vals, Vals+NumVals), Packed); 331 } 332 333 /// getType() specialization - Reduce amount of casting... 334 /// 335 inline const StructType *getType() const { 336 return reinterpret_cast<const StructType*>(Value::getType()); 337 } 338 339 /// isNullValue - Return true if this is the value that would be returned by 340 /// getNullValue. This always returns false because zero structs are always 341 /// created as ConstantAggregateZero objects. 342 virtual bool isNullValue() const { 343 return false; 344 } 345 346 virtual void destroyConstant(); 347 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U); 348 349 /// Methods for support type inquiry through isa, cast, and dyn_cast: 350 static inline bool classof(const ConstantStruct *) { return true; } 351 static bool classof(const Value *V) { 352 return V->getValueType() == ConstantStructVal; 353 } 354}; 355 356//===----------------------------------------------------------------------===// 357/// ConstantVector - Constant Vector Declarations 358/// 359class ConstantVector : public Constant { 360 friend struct ConstantCreator<ConstantVector, VectorType, 361 std::vector<Constant*> >; 362 ConstantVector(const ConstantVector &); // DO NOT IMPLEMENT 363protected: 364 ConstantVector(const VectorType *T, const std::vector<Constant*> &Val); 365 ~ConstantVector(); 366public: 367 /// get() - Static factory methods - Return objects of the specified value 368 static Constant *get(const VectorType *T, const std::vector<Constant*> &); 369 static Constant *get(const std::vector<Constant*> &V); 370 static Constant *get(Constant*const* Vals, unsigned NumVals) { 371 // FIXME: make this the primary ctor method. 372 return get(std::vector<Constant*>(Vals, Vals+NumVals)); 373 } 374 375 /// getType - Specialize the getType() method to always return an VectorType, 376 /// which reduces the amount of casting needed in parts of the compiler. 377 /// 378 inline const VectorType *getType() const { 379 return reinterpret_cast<const VectorType*>(Value::getType()); 380 } 381 382 /// @returns the value for an packed integer constant of the given type that 383 /// has all its bits set to true. 384 /// @brief Get the all ones value 385 static ConstantVector *getAllOnesValue(const VectorType *Ty); 386 387 /// isNullValue - Return true if this is the value that would be returned by 388 /// getNullValue. This always returns false because zero arrays are always 389 /// created as ConstantAggregateZero objects. 390 virtual bool isNullValue() const { return false; } 391 392 /// This function will return true iff every element in this packed constant 393 /// is set to all ones. 394 /// @returns true iff this constant's emements are all set to all ones. 395 /// @brief Determine if the value is all ones. 396 bool isAllOnesValue() const; 397 398 virtual void destroyConstant(); 399 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U); 400 401 /// Methods for support type inquiry through isa, cast, and dyn_cast: 402 static inline bool classof(const ConstantVector *) { return true; } 403 static bool classof(const Value *V) { 404 return V->getValueType() == ConstantVectorVal; 405 } 406}; 407 408//===----------------------------------------------------------------------===// 409/// ConstantPointerNull - a constant pointer value that points to null 410/// 411class ConstantPointerNull : public Constant { 412 friend struct ConstantCreator<ConstantPointerNull, PointerType, char>; 413 ConstantPointerNull(const ConstantPointerNull &); // DO NOT IMPLEMENT 414protected: 415 ConstantPointerNull(const PointerType *T) 416 : Constant(reinterpret_cast<const Type*>(T), 417 Value::ConstantPointerNullVal, 0, 0) {} 418 419public: 420 421 /// get() - Static factory methods - Return objects of the specified value 422 static ConstantPointerNull *get(const PointerType *T); 423 424 /// isNullValue - Return true if this is the value that would be returned by 425 /// getNullValue. 426 virtual bool isNullValue() const { return true; } 427 428 virtual void destroyConstant(); 429 430 /// getType - Specialize the getType() method to always return an PointerType, 431 /// which reduces the amount of casting needed in parts of the compiler. 432 /// 433 inline const PointerType *getType() const { 434 return reinterpret_cast<const PointerType*>(Value::getType()); 435 } 436 437 /// Methods for support type inquiry through isa, cast, and dyn_cast: 438 static inline bool classof(const ConstantPointerNull *) { return true; } 439 static bool classof(const Value *V) { 440 return V->getValueType() == ConstantPointerNullVal; 441 } 442}; 443 444 445/// ConstantExpr - a constant value that is initialized with an expression using 446/// other constant values. 447/// 448/// This class uses the standard Instruction opcodes to define the various 449/// constant expressions. The Opcode field for the ConstantExpr class is 450/// maintained in the Value::SubclassData field. 451class ConstantExpr : public Constant { 452 friend struct ConstantCreator<ConstantExpr,Type, 453 std::pair<unsigned, std::vector<Constant*> > >; 454 friend struct ConvertConstantType<ConstantExpr, Type>; 455 456protected: 457 ConstantExpr(const Type *Ty, unsigned Opcode, Use *Ops, unsigned NumOps) 458 : Constant(Ty, ConstantExprVal, Ops, NumOps) { 459 // Operation type (an Instruction opcode) is stored as the SubclassData. 460 SubclassData = Opcode; 461 } 462 463 // These private methods are used by the type resolution code to create 464 // ConstantExprs in intermediate forms. 465 static Constant *getTy(const Type *Ty, unsigned Opcode, 466 Constant *C1, Constant *C2); 467 static Constant *getCompareTy(unsigned short pred, Constant *C1, 468 Constant *C2); 469 static Constant *getSelectTy(const Type *Ty, 470 Constant *C1, Constant *C2, Constant *C3); 471 static Constant *getGetElementPtrTy(const Type *Ty, Constant *C, 472 Value* const *Idxs, unsigned NumIdxs); 473 static Constant *getExtractElementTy(const Type *Ty, Constant *Val, 474 Constant *Idx); 475 static Constant *getInsertElementTy(const Type *Ty, Constant *Val, 476 Constant *Elt, Constant *Idx); 477 static Constant *getShuffleVectorTy(const Type *Ty, Constant *V1, 478 Constant *V2, Constant *Mask); 479 480public: 481 // Static methods to construct a ConstantExpr of different kinds. Note that 482 // these methods may return a object that is not an instance of the 483 // ConstantExpr class, because they will attempt to fold the constant 484 // expression into something simpler if possible. 485 486 /// Cast constant expr 487 /// 488 static Constant *getTrunc (Constant *C, const Type *Ty); 489 static Constant *getSExt (Constant *C, const Type *Ty); 490 static Constant *getZExt (Constant *C, const Type *Ty); 491 static Constant *getFPTrunc (Constant *C, const Type *Ty); 492 static Constant *getFPExtend(Constant *C, const Type *Ty); 493 static Constant *getUIToFP (Constant *C, const Type *Ty); 494 static Constant *getSIToFP (Constant *C, const Type *Ty); 495 static Constant *getFPToUI (Constant *C, const Type *Ty); 496 static Constant *getFPToSI (Constant *C, const Type *Ty); 497 static Constant *getPtrToInt(Constant *C, const Type *Ty); 498 static Constant *getIntToPtr(Constant *C, const Type *Ty); 499 static Constant *getBitCast (Constant *C, const Type *Ty); 500 501 // @brief Convenience function for getting one of the casting operations 502 // using a CastOps opcode. 503 static Constant *getCast( 504 unsigned ops, ///< The opcode for the conversion 505 Constant *C, ///< The constant to be converted 506 const Type *Ty ///< The type to which the constant is converted 507 ); 508 509 // @brief Create a ZExt or BitCast cast constant expression 510 static Constant *getZExtOrBitCast( 511 Constant *C, ///< The constant to zext or bitcast 512 const Type *Ty ///< The type to zext or bitcast C to 513 ); 514 515 // @brief Create a SExt or BitCast cast constant expression 516 static Constant *getSExtOrBitCast( 517 Constant *C, ///< The constant to sext or bitcast 518 const Type *Ty ///< The type to sext or bitcast C to 519 ); 520 521 // @brief Create a Trunc or BitCast cast constant expression 522 static Constant *getTruncOrBitCast( 523 Constant *C, ///< The constant to trunc or bitcast 524 const Type *Ty ///< The type to trunc or bitcast C to 525 ); 526 527 /// @brief Create a BitCast or a PtrToInt cast constant expression 528 static Constant *getPointerCast( 529 Constant *C, ///< The pointer value to be casted (operand 0) 530 const Type *Ty ///< The type to which cast should be made 531 ); 532 533 /// @brief Create a ZExt, Bitcast or Trunc for integer -> integer casts 534 static Constant *getIntegerCast( 535 Constant *C, ///< The integer constant to be casted 536 const Type *Ty, ///< The integer type to cast to 537 bool isSigned ///< Whether C should be treated as signed or not 538 ); 539 540 /// @brief Create a FPExt, Bitcast or FPTrunc for fp -> fp casts 541 static Constant *getFPCast( 542 Constant *C, ///< The integer constant to be casted 543 const Type *Ty ///< The integer type to cast to 544 ); 545 546 /// @brief Return true if this is a convert constant expression 547 bool isCast() const; 548 549 /// @brief Return true if this is a compare constant expression 550 bool isCompare() const; 551 552 /// Select constant expr 553 /// 554 static Constant *getSelect(Constant *C, Constant *V1, Constant *V2) { 555 return getSelectTy(V1->getType(), C, V1, V2); 556 } 557 558 /// getSizeOf constant expr - computes the size of a type in a target 559 /// independent way (Note: the return type is a ULong). 560 /// 561 static Constant *getSizeOf(const Type *Ty); 562 563 /// ConstantExpr::get - Return a binary or shift operator constant expression, 564 /// folding if possible. 565 /// 566 static Constant *get(unsigned Opcode, Constant *C1, Constant *C2); 567 568 /// @brief Return an ICmp or FCmp comparison operator constant expression. 569 static Constant *getCompare(unsigned short pred, Constant *C1, Constant *C2); 570 571 /// ConstantExpr::get* - Return some common constants without having to 572 /// specify the full Instruction::OPCODE identifier. 573 /// 574 static Constant *getNeg(Constant *C); 575 static Constant *getNot(Constant *C); 576 static Constant *getAdd(Constant *C1, Constant *C2); 577 static Constant *getSub(Constant *C1, Constant *C2); 578 static Constant *getMul(Constant *C1, Constant *C2); 579 static Constant *getUDiv(Constant *C1, Constant *C2); 580 static Constant *getSDiv(Constant *C1, Constant *C2); 581 static Constant *getFDiv(Constant *C1, Constant *C2); 582 static Constant *getURem(Constant *C1, Constant *C2); // unsigned rem 583 static Constant *getSRem(Constant *C1, Constant *C2); // signed rem 584 static Constant *getFRem(Constant *C1, Constant *C2); 585 static Constant *getAnd(Constant *C1, Constant *C2); 586 static Constant *getOr(Constant *C1, Constant *C2); 587 static Constant *getXor(Constant *C1, Constant *C2); 588 static Constant* getICmp(unsigned short pred, Constant* LHS, Constant* RHS); 589 static Constant* getFCmp(unsigned short pred, Constant* LHS, Constant* RHS); 590 static Constant *getShl(Constant *C1, Constant *C2); 591 static Constant *getLShr(Constant *C1, Constant *C2); 592 static Constant *getAShr(Constant *C1, Constant *C2); 593 594 /// Getelementptr form. std::vector<Value*> is only accepted for convenience: 595 /// all elements must be Constant's. 596 /// 597 static Constant *getGetElementPtr(Constant *C, 598 Constant* const *IdxList, unsigned NumIdx); 599 static Constant *getGetElementPtr(Constant *C, 600 Value* const *IdxList, unsigned NumIdx); 601 602 static Constant *getExtractElement(Constant *Vec, Constant *Idx); 603 static Constant *getInsertElement(Constant *Vec, Constant *Elt,Constant *Idx); 604 static Constant *getShuffleVector(Constant *V1, Constant *V2, Constant *Mask); 605 606 /// Floating point negation must be implemented with f(x) = -0.0 - x. This 607 /// method returns the negative zero constant for floating point or packed 608 /// floating point types; for all other types, it returns the null value. 609 static Constant *getZeroValueForNegationExpr(const Type *Ty); 610 611 /// isNullValue - Return true if this is the value that would be returned by 612 /// getNullValue. 613 virtual bool isNullValue() const { return false; } 614 615 /// getOpcode - Return the opcode at the root of this constant expression 616 unsigned getOpcode() const { return SubclassData; } 617 618 /// getPredicate - Return the ICMP or FCMP predicate value. Assert if this is 619 /// not an ICMP or FCMP constant expression. 620 unsigned getPredicate() const; 621 622 /// getOpcodeName - Return a string representation for an opcode. 623 const char *getOpcodeName() const; 624 625 /// getWithOperandReplaced - Return a constant expression identical to this 626 /// one, but with the specified operand set to the specified value. 627 Constant *getWithOperandReplaced(unsigned OpNo, Constant *Op) const; 628 629 /// getWithOperands - This returns the current constant expression with the 630 /// operands replaced with the specified values. The specified operands must 631 /// match count and type with the existing ones. 632 Constant *getWithOperands(const std::vector<Constant*> &Ops) const; 633 634 virtual void destroyConstant(); 635 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U); 636 637 /// Override methods to provide more type information... 638 inline Constant *getOperand(unsigned i) { 639 return cast<Constant>(User::getOperand(i)); 640 } 641 inline Constant *getOperand(unsigned i) const { 642 return const_cast<Constant*>(cast<Constant>(User::getOperand(i))); 643 } 644 645 646 /// Methods for support type inquiry through isa, cast, and dyn_cast: 647 static inline bool classof(const ConstantExpr *) { return true; } 648 static inline bool classof(const Value *V) { 649 return V->getValueType() == ConstantExprVal; 650 } 651}; 652 653 654//===----------------------------------------------------------------------===// 655/// UndefValue - 'undef' values are things that do not have specified contents. 656/// These are used for a variety of purposes, including global variable 657/// initializers and operands to instructions. 'undef' values can occur with 658/// any type. 659/// 660class UndefValue : public Constant { 661 friend struct ConstantCreator<UndefValue, Type, char>; 662 UndefValue(const UndefValue &); // DO NOT IMPLEMENT 663protected: 664 UndefValue(const Type *T) : Constant(T, UndefValueVal, 0, 0) {} 665public: 666 /// get() - Static factory methods - Return an 'undef' object of the specified 667 /// type. 668 /// 669 static UndefValue *get(const Type *T); 670 671 /// isNullValue - Return true if this is the value that would be returned by 672 /// getNullValue. 673 virtual bool isNullValue() const { return false; } 674 675 virtual void destroyConstant(); 676 677 /// Methods for support type inquiry through isa, cast, and dyn_cast: 678 static inline bool classof(const UndefValue *) { return true; } 679 static bool classof(const Value *V) { 680 return V->getValueType() == UndefValueVal; 681 } 682}; 683 684} // End llvm namespace 685 686#endif 687