1 //===-- llvm/Constants.h - Constant class subclass definitions --*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 /// @file 10 /// 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. Constants 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_IR_CONSTANTS_H 21 #define LLVM_IR_CONSTANTS_H 22 23 #include "llvm/ADT/APFloat.h" 24 #include "llvm/ADT/APInt.h" 25 #include "llvm/ADT/ArrayRef.h" 26 #include "llvm/ADT/None.h" 27 #include "llvm/ADT/Optional.h" 28 #include "llvm/ADT/STLExtras.h" 29 #include "llvm/ADT/StringRef.h" 30 #include "llvm/IR/Constant.h" 31 #include "llvm/IR/DerivedTypes.h" 32 #include "llvm/IR/OperandTraits.h" 33 #include "llvm/IR/User.h" 34 #include "llvm/IR/Value.h" 35 #include "llvm/Support/Casting.h" 36 #include "llvm/Support/Compiler.h" 37 #include "llvm/Support/ErrorHandling.h" 38 #include <cassert> 39 #include <cstddef> 40 #include <cstdint> 41 42 namespace llvm { 43 44 template <class ConstantClass> struct ConstantAggrKeyType; 45 46 /// Base class for constants with no operands. 47 /// 48 /// These constants have no operands; they represent their data directly. 49 /// Since they can be in use by unrelated modules (and are never based on 50 /// GlobalValues), it never makes sense to RAUW them. 51 class ConstantData : public Constant { 52 friend class Constant; 53 handleOperandChangeImpl(Value * From,Value * To)54 Value *handleOperandChangeImpl(Value *From, Value *To) { 55 llvm_unreachable("Constant data does not have operands!"); 56 } 57 58 protected: ConstantData(Type * Ty,ValueTy VT)59 explicit ConstantData(Type *Ty, ValueTy VT) : Constant(Ty, VT, nullptr, 0) {} 60 new(size_t s)61 void *operator new(size_t s) { return User::operator new(s, 0); } 62 63 public: 64 ConstantData(const ConstantData &) = delete; 65 66 /// Methods to support type inquiry through isa, cast, and dyn_cast. classof(const Value * V)67 static bool classof(const Value *V) { 68 return V->getValueID() >= ConstantDataFirstVal && 69 V->getValueID() <= ConstantDataLastVal; 70 } 71 }; 72 73 //===----------------------------------------------------------------------===// 74 /// This is the shared class of boolean and integer constants. This class 75 /// represents both boolean and integral constants. 76 /// Class for constant integers. 77 class ConstantInt final : public ConstantData { 78 friend class Constant; 79 80 APInt Val; 81 82 ConstantInt(IntegerType *Ty, const APInt &V); 83 84 void destroyConstantImpl(); 85 86 public: 87 ConstantInt(const ConstantInt &) = delete; 88 89 static ConstantInt *getTrue(LLVMContext &Context); 90 static ConstantInt *getFalse(LLVMContext &Context); 91 static ConstantInt *getBool(LLVMContext &Context, bool V); 92 static Constant *getTrue(Type *Ty); 93 static Constant *getFalse(Type *Ty); 94 static Constant *getBool(Type *Ty, bool V); 95 96 /// If Ty is a vector type, return a Constant with a splat of the given 97 /// value. Otherwise return a ConstantInt for the given value. 98 static Constant *get(Type *Ty, uint64_t V, bool IsSigned = false); 99 100 /// Return a ConstantInt with the specified integer value for the specified 101 /// type. If the type is wider than 64 bits, the value will be zero-extended 102 /// to fit the type, unless IsSigned is true, in which case the value will 103 /// be interpreted as a 64-bit signed integer and sign-extended to fit 104 /// the type. 105 /// Get a ConstantInt for a specific value. 106 static ConstantInt *get(IntegerType *Ty, uint64_t V, bool IsSigned = false); 107 108 /// Return a ConstantInt with the specified value for the specified type. The 109 /// value V will be canonicalized to a an unsigned APInt. Accessing it with 110 /// either getSExtValue() or getZExtValue() will yield a correctly sized and 111 /// signed value for the type Ty. 112 /// Get a ConstantInt for a specific signed value. 113 static ConstantInt *getSigned(IntegerType *Ty, int64_t V); 114 static Constant *getSigned(Type *Ty, int64_t V); 115 116 /// Return a ConstantInt with the specified value and an implied Type. The 117 /// type is the integer type that corresponds to the bit width of the value. 118 static ConstantInt *get(LLVMContext &Context, const APInt &V); 119 120 /// Return a ConstantInt constructed from the string strStart with the given 121 /// radix. 122 static ConstantInt *get(IntegerType *Ty, StringRef Str, uint8_t Radix); 123 124 /// If Ty is a vector type, return a Constant with a splat of the given 125 /// value. Otherwise return a ConstantInt for the given value. 126 static Constant *get(Type *Ty, const APInt &V); 127 128 /// Return the constant as an APInt value reference. This allows clients to 129 /// obtain a full-precision copy of the value. 130 /// Return the constant's value. getValue()131 inline const APInt &getValue() const { return Val; } 132 133 /// getBitWidth - Return the bitwidth of this constant. getBitWidth()134 unsigned getBitWidth() const { return Val.getBitWidth(); } 135 136 /// Return the constant as a 64-bit unsigned integer value after it 137 /// has been zero extended as appropriate for the type of this constant. Note 138 /// that this method can assert if the value does not fit in 64 bits. 139 /// Return the zero extended value. getZExtValue()140 inline uint64_t getZExtValue() const { return Val.getZExtValue(); } 141 142 /// Return the constant as a 64-bit integer value after it has been sign 143 /// extended as appropriate for the type of this constant. Note that 144 /// this method can assert if the value does not fit in 64 bits. 145 /// Return the sign extended value. getSExtValue()146 inline int64_t getSExtValue() const { return Val.getSExtValue(); } 147 148 /// Return the constant as an llvm::MaybeAlign. 149 /// Note that this method can assert if the value does not fit in 64 bits or 150 /// is not a power of two. getMaybeAlignValue()151 inline MaybeAlign getMaybeAlignValue() const { 152 return MaybeAlign(getZExtValue()); 153 } 154 155 /// Return the constant as an llvm::Align, interpreting `0` as `Align(1)`. 156 /// Note that this method can assert if the value does not fit in 64 bits or 157 /// is not a power of two. getAlignValue()158 inline Align getAlignValue() const { 159 return getMaybeAlignValue().valueOrOne(); 160 } 161 162 /// A helper method that can be used to determine if the constant contained 163 /// within is equal to a constant. This only works for very small values, 164 /// because this is all that can be represented with all types. 165 /// Determine if this constant's value is same as an unsigned char. equalsInt(uint64_t V)166 bool equalsInt(uint64_t V) const { return Val == V; } 167 168 /// getType - Specialize the getType() method to always return an IntegerType, 169 /// which reduces the amount of casting needed in parts of the compiler. 170 /// getType()171 inline IntegerType *getType() const { 172 return cast<IntegerType>(Value::getType()); 173 } 174 175 /// This static method returns true if the type Ty is big enough to 176 /// represent the value V. This can be used to avoid having the get method 177 /// assert when V is larger than Ty can represent. Note that there are two 178 /// versions of this method, one for unsigned and one for signed integers. 179 /// Although ConstantInt canonicalizes everything to an unsigned integer, 180 /// the signed version avoids callers having to convert a signed quantity 181 /// to the appropriate unsigned type before calling the method. 182 /// @returns true if V is a valid value for type Ty 183 /// Determine if the value is in range for the given type. 184 static bool isValueValidForType(Type *Ty, uint64_t V); 185 static bool isValueValidForType(Type *Ty, int64_t V); 186 isNegative()187 bool isNegative() const { return Val.isNegative(); } 188 189 /// This is just a convenience method to make client code smaller for a 190 /// common code. It also correctly performs the comparison without the 191 /// potential for an assertion from getZExtValue(). isZero()192 bool isZero() const { return Val.isNullValue(); } 193 194 /// This is just a convenience method to make client code smaller for a 195 /// common case. It also correctly performs the comparison without the 196 /// potential for an assertion from getZExtValue(). 197 /// Determine if the value is one. isOne()198 bool isOne() const { return Val.isOneValue(); } 199 200 /// This function will return true iff every bit in this constant is set 201 /// to true. 202 /// @returns true iff this constant's bits are all set to true. 203 /// Determine if the value is all ones. isMinusOne()204 bool isMinusOne() const { return Val.isAllOnesValue(); } 205 206 /// This function will return true iff this constant represents the largest 207 /// value that may be represented by the constant's type. 208 /// @returns true iff this is the largest value that may be represented 209 /// by this type. 210 /// Determine if the value is maximal. isMaxValue(bool IsSigned)211 bool isMaxValue(bool IsSigned) const { 212 if (IsSigned) 213 return Val.isMaxSignedValue(); 214 else 215 return Val.isMaxValue(); 216 } 217 218 /// This function will return true iff this constant represents the smallest 219 /// value that may be represented by this constant's type. 220 /// @returns true if this is the smallest value that may be represented by 221 /// this type. 222 /// Determine if the value is minimal. isMinValue(bool IsSigned)223 bool isMinValue(bool IsSigned) const { 224 if (IsSigned) 225 return Val.isMinSignedValue(); 226 else 227 return Val.isMinValue(); 228 } 229 230 /// This function will return true iff this constant represents a value with 231 /// active bits bigger than 64 bits or a value greater than the given uint64_t 232 /// value. 233 /// @returns true iff this constant is greater or equal to the given number. 234 /// Determine if the value is greater or equal to the given number. uge(uint64_t Num)235 bool uge(uint64_t Num) const { return Val.uge(Num); } 236 237 /// getLimitedValue - If the value is smaller than the specified limit, 238 /// return it, otherwise return the limit value. This causes the value 239 /// to saturate to the limit. 240 /// @returns the min of the value of the constant and the specified value 241 /// Get the constant's value with a saturation limit 242 uint64_t getLimitedValue(uint64_t Limit = ~0ULL) const { 243 return Val.getLimitedValue(Limit); 244 } 245 246 /// Methods to support type inquiry through isa, cast, and dyn_cast. classof(const Value * V)247 static bool classof(const Value *V) { 248 return V->getValueID() == ConstantIntVal; 249 } 250 }; 251 252 //===----------------------------------------------------------------------===// 253 /// ConstantFP - Floating Point Values [float, double] 254 /// 255 class ConstantFP final : public ConstantData { 256 friend class Constant; 257 258 APFloat Val; 259 260 ConstantFP(Type *Ty, const APFloat &V); 261 262 void destroyConstantImpl(); 263 264 public: 265 ConstantFP(const ConstantFP &) = delete; 266 267 /// Floating point negation must be implemented with f(x) = -0.0 - x. This 268 /// method returns the negative zero constant for floating point or vector 269 /// floating point types; for all other types, it returns the null value. 270 static Constant *getZeroValueForNegation(Type *Ty); 271 272 /// This returns a ConstantFP, or a vector containing a splat of a ConstantFP, 273 /// for the specified value in the specified type. This should only be used 274 /// for simple constant values like 2.0/1.0 etc, that are known-valid both as 275 /// host double and as the target format. 276 static Constant *get(Type *Ty, double V); 277 278 /// If Ty is a vector type, return a Constant with a splat of the given 279 /// value. Otherwise return a ConstantFP for the given value. 280 static Constant *get(Type *Ty, const APFloat &V); 281 282 static Constant *get(Type *Ty, StringRef Str); 283 static ConstantFP *get(LLVMContext &Context, const APFloat &V); 284 static Constant *getNaN(Type *Ty, bool Negative = false, 285 uint64_t Payload = 0); 286 static Constant *getQNaN(Type *Ty, bool Negative = false, 287 APInt *Payload = nullptr); 288 static Constant *getSNaN(Type *Ty, bool Negative = false, 289 APInt *Payload = nullptr); 290 static Constant *getNegativeZero(Type *Ty); 291 static Constant *getInfinity(Type *Ty, bool Negative = false); 292 293 /// Return true if Ty is big enough to represent V. 294 static bool isValueValidForType(Type *Ty, const APFloat &V); getValueAPF()295 inline const APFloat &getValueAPF() const { return Val; } getValue()296 inline const APFloat &getValue() const { return Val; } 297 298 /// Return true if the value is positive or negative zero. isZero()299 bool isZero() const { return Val.isZero(); } 300 301 /// Return true if the sign bit is set. isNegative()302 bool isNegative() const { return Val.isNegative(); } 303 304 /// Return true if the value is infinity isInfinity()305 bool isInfinity() const { return Val.isInfinity(); } 306 307 /// Return true if the value is a NaN. isNaN()308 bool isNaN() const { return Val.isNaN(); } 309 310 /// We don't rely on operator== working on double values, as it returns true 311 /// for things that are clearly not equal, like -0.0 and 0.0. 312 /// As such, this method can be used to do an exact bit-for-bit comparison of 313 /// two floating point values. The version with a double operand is retained 314 /// because it's so convenient to write isExactlyValue(2.0), but please use 315 /// it only for simple constants. 316 bool isExactlyValue(const APFloat &V) const; 317 isExactlyValue(double V)318 bool isExactlyValue(double V) const { 319 bool ignored; 320 APFloat FV(V); 321 FV.convert(Val.getSemantics(), APFloat::rmNearestTiesToEven, &ignored); 322 return isExactlyValue(FV); 323 } 324 325 /// Methods for support type inquiry through isa, cast, and dyn_cast: classof(const Value * V)326 static bool classof(const Value *V) { 327 return V->getValueID() == ConstantFPVal; 328 } 329 }; 330 331 //===----------------------------------------------------------------------===// 332 /// All zero aggregate value 333 /// 334 class ConstantAggregateZero final : public ConstantData { 335 friend class Constant; 336 ConstantAggregateZero(Type * Ty)337 explicit ConstantAggregateZero(Type *Ty) 338 : ConstantData(Ty, ConstantAggregateZeroVal) {} 339 340 void destroyConstantImpl(); 341 342 public: 343 ConstantAggregateZero(const ConstantAggregateZero &) = delete; 344 345 static ConstantAggregateZero *get(Type *Ty); 346 347 /// If this CAZ has array or vector type, return a zero with the right element 348 /// type. 349 Constant *getSequentialElement() const; 350 351 /// If this CAZ has struct type, return a zero with the right element type for 352 /// the specified element. 353 Constant *getStructElement(unsigned Elt) const; 354 355 /// Return a zero of the right value for the specified GEP index if we can, 356 /// otherwise return null (e.g. if C is a ConstantExpr). 357 Constant *getElementValue(Constant *C) const; 358 359 /// Return a zero of the right value for the specified GEP index. 360 Constant *getElementValue(unsigned Idx) const; 361 362 /// Return the number of elements in the array, vector, or struct. 363 ElementCount getElementCount() const; 364 365 /// Methods for support type inquiry through isa, cast, and dyn_cast: 366 /// classof(const Value * V)367 static bool classof(const Value *V) { 368 return V->getValueID() == ConstantAggregateZeroVal; 369 } 370 }; 371 372 /// Base class for aggregate constants (with operands). 373 /// 374 /// These constants are aggregates of other constants, which are stored as 375 /// operands. 376 /// 377 /// Subclasses are \a ConstantStruct, \a ConstantArray, and \a 378 /// ConstantVector. 379 /// 380 /// \note Some subclasses of \a ConstantData are semantically aggregates -- 381 /// such as \a ConstantDataArray -- but are not subclasses of this because they 382 /// use operands. 383 class ConstantAggregate : public Constant { 384 protected: 385 ConstantAggregate(Type *T, ValueTy VT, ArrayRef<Constant *> V); 386 387 public: 388 /// Transparently provide more efficient getOperand methods. 389 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant); 390 391 /// Methods for support type inquiry through isa, cast, and dyn_cast: classof(const Value * V)392 static bool classof(const Value *V) { 393 return V->getValueID() >= ConstantAggregateFirstVal && 394 V->getValueID() <= ConstantAggregateLastVal; 395 } 396 }; 397 398 template <> 399 struct OperandTraits<ConstantAggregate> 400 : public VariadicOperandTraits<ConstantAggregate> {}; 401 402 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantAggregate, Constant) 403 404 //===----------------------------------------------------------------------===// 405 /// ConstantArray - Constant Array Declarations 406 /// 407 class ConstantArray final : public ConstantAggregate { 408 friend struct ConstantAggrKeyType<ConstantArray>; 409 friend class Constant; 410 411 ConstantArray(ArrayType *T, ArrayRef<Constant *> Val); 412 413 void destroyConstantImpl(); 414 Value *handleOperandChangeImpl(Value *From, Value *To); 415 416 public: 417 // ConstantArray accessors 418 static Constant *get(ArrayType *T, ArrayRef<Constant *> V); 419 420 private: 421 static Constant *getImpl(ArrayType *T, ArrayRef<Constant *> V); 422 423 public: 424 /// Specialize the getType() method to always return an ArrayType, 425 /// which reduces the amount of casting needed in parts of the compiler. 426 inline ArrayType *getType() const { 427 return cast<ArrayType>(Value::getType()); 428 } 429 430 /// Methods for support type inquiry through isa, cast, and dyn_cast: 431 static bool classof(const Value *V) { 432 return V->getValueID() == ConstantArrayVal; 433 } 434 }; 435 436 //===----------------------------------------------------------------------===// 437 // Constant Struct Declarations 438 // 439 class ConstantStruct final : public ConstantAggregate { 440 friend struct ConstantAggrKeyType<ConstantStruct>; 441 friend class Constant; 442 443 ConstantStruct(StructType *T, ArrayRef<Constant *> Val); 444 445 void destroyConstantImpl(); 446 Value *handleOperandChangeImpl(Value *From, Value *To); 447 448 public: 449 // ConstantStruct accessors 450 static Constant *get(StructType *T, ArrayRef<Constant *> V); 451 452 template <typename... Csts> 453 static std::enable_if_t<are_base_of<Constant, Csts...>::value, Constant *> 454 get(StructType *T, Csts *...Vs) { 455 SmallVector<Constant *, 8> Values({Vs...}); 456 return get(T, Values); 457 } 458 459 /// Return an anonymous struct that has the specified elements. 460 /// If the struct is possibly empty, then you must specify a context. 461 static Constant *getAnon(ArrayRef<Constant *> V, bool Packed = false) { 462 return get(getTypeForElements(V, Packed), V); 463 } 464 static Constant *getAnon(LLVMContext &Ctx, ArrayRef<Constant *> V, 465 bool Packed = false) { 466 return get(getTypeForElements(Ctx, V, Packed), V); 467 } 468 469 /// Return an anonymous struct type to use for a constant with the specified 470 /// set of elements. The list must not be empty. 471 static StructType *getTypeForElements(ArrayRef<Constant *> V, 472 bool Packed = false); 473 /// This version of the method allows an empty list. 474 static StructType *getTypeForElements(LLVMContext &Ctx, 475 ArrayRef<Constant *> V, 476 bool Packed = false); 477 478 /// Specialization - reduce amount of casting. 479 inline StructType *getType() const { 480 return cast<StructType>(Value::getType()); 481 } 482 483 /// Methods for support type inquiry through isa, cast, and dyn_cast: 484 static bool classof(const Value *V) { 485 return V->getValueID() == ConstantStructVal; 486 } 487 }; 488 489 //===----------------------------------------------------------------------===// 490 /// Constant Vector Declarations 491 /// 492 class ConstantVector final : public ConstantAggregate { 493 friend struct ConstantAggrKeyType<ConstantVector>; 494 friend class Constant; 495 496 ConstantVector(VectorType *T, ArrayRef<Constant *> Val); 497 498 void destroyConstantImpl(); 499 Value *handleOperandChangeImpl(Value *From, Value *To); 500 501 public: 502 // ConstantVector accessors 503 static Constant *get(ArrayRef<Constant *> V); 504 505 private: 506 static Constant *getImpl(ArrayRef<Constant *> V); 507 508 public: 509 /// Return a ConstantVector with the specified constant in each element. 510 /// Note that this might not return an instance of ConstantVector 511 static Constant *getSplat(ElementCount EC, Constant *Elt); 512 513 /// Specialize the getType() method to always return a FixedVectorType, 514 /// which reduces the amount of casting needed in parts of the compiler. 515 inline FixedVectorType *getType() const { 516 return cast<FixedVectorType>(Value::getType()); 517 } 518 519 /// If all elements of the vector constant have the same value, return that 520 /// value. Otherwise, return nullptr. Ignore undefined elements by setting 521 /// AllowUndefs to true. 522 Constant *getSplatValue(bool AllowUndefs = false) const; 523 524 /// Methods for support type inquiry through isa, cast, and dyn_cast: 525 static bool classof(const Value *V) { 526 return V->getValueID() == ConstantVectorVal; 527 } 528 }; 529 530 //===----------------------------------------------------------------------===// 531 /// A constant pointer value that points to null 532 /// 533 class ConstantPointerNull final : public ConstantData { 534 friend class Constant; 535 536 explicit ConstantPointerNull(PointerType *T) 537 : ConstantData(T, Value::ConstantPointerNullVal) {} 538 539 void destroyConstantImpl(); 540 541 public: 542 ConstantPointerNull(const ConstantPointerNull &) = delete; 543 544 /// Static factory methods - Return objects of the specified value 545 static ConstantPointerNull *get(PointerType *T); 546 547 /// Specialize the getType() method to always return an PointerType, 548 /// which reduces the amount of casting needed in parts of the compiler. 549 inline PointerType *getType() const { 550 return cast<PointerType>(Value::getType()); 551 } 552 553 /// Methods for support type inquiry through isa, cast, and dyn_cast: 554 static bool classof(const Value *V) { 555 return V->getValueID() == ConstantPointerNullVal; 556 } 557 }; 558 559 //===----------------------------------------------------------------------===// 560 /// ConstantDataSequential - A vector or array constant whose element type is a 561 /// simple 1/2/4/8-byte integer or half/bfloat/float/double, and whose elements 562 /// are just simple data values (i.e. ConstantInt/ConstantFP). This Constant 563 /// node has no operands because it stores all of the elements of the constant 564 /// as densely packed data, instead of as Value*'s. 565 /// 566 /// This is the common base class of ConstantDataArray and ConstantDataVector. 567 /// 568 class ConstantDataSequential : public ConstantData { 569 friend class LLVMContextImpl; 570 friend class Constant; 571 572 /// A pointer to the bytes underlying this constant (which is owned by the 573 /// uniquing StringMap). 574 const char *DataElements; 575 576 /// This forms a link list of ConstantDataSequential nodes that have 577 /// the same value but different type. For example, 0,0,0,1 could be a 4 578 /// element array of i8, or a 1-element array of i32. They'll both end up in 579 /// the same StringMap bucket, linked up. 580 std::unique_ptr<ConstantDataSequential> Next; 581 582 void destroyConstantImpl(); 583 584 protected: 585 explicit ConstantDataSequential(Type *ty, ValueTy VT, const char *Data) 586 : ConstantData(ty, VT), DataElements(Data) {} 587 588 static Constant *getImpl(StringRef Bytes, Type *Ty); 589 590 public: 591 ConstantDataSequential(const ConstantDataSequential &) = delete; 592 593 /// Return true if a ConstantDataSequential can be formed with a vector or 594 /// array of the specified element type. 595 /// ConstantDataArray only works with normal float and int types that are 596 /// stored densely in memory, not with things like i42 or x86_f80. 597 static bool isElementTypeCompatible(Type *Ty); 598 599 /// If this is a sequential container of integers (of any size), return the 600 /// specified element in the low bits of a uint64_t. 601 uint64_t getElementAsInteger(unsigned i) const; 602 603 /// If this is a sequential container of integers (of any size), return the 604 /// specified element as an APInt. 605 APInt getElementAsAPInt(unsigned i) const; 606 607 /// If this is a sequential container of floating point type, return the 608 /// specified element as an APFloat. 609 APFloat getElementAsAPFloat(unsigned i) const; 610 611 /// If this is an sequential container of floats, return the specified element 612 /// as a float. 613 float getElementAsFloat(unsigned i) const; 614 615 /// If this is an sequential container of doubles, return the specified 616 /// element as a double. 617 double getElementAsDouble(unsigned i) const; 618 619 /// Return a Constant for a specified index's element. 620 /// Note that this has to compute a new constant to return, so it isn't as 621 /// efficient as getElementAsInteger/Float/Double. 622 Constant *getElementAsConstant(unsigned i) const; 623 624 /// Return the element type of the array/vector. 625 Type *getElementType() const; 626 627 /// Return the number of elements in the array or vector. 628 unsigned getNumElements() const; 629 630 /// Return the size (in bytes) of each element in the array/vector. 631 /// The size of the elements is known to be a multiple of one byte. 632 uint64_t getElementByteSize() const; 633 634 /// This method returns true if this is an array of \p CharSize integers. 635 bool isString(unsigned CharSize = 8) const; 636 637 /// This method returns true if the array "isString", ends with a null byte, 638 /// and does not contains any other null bytes. 639 bool isCString() const; 640 641 /// If this array is isString(), then this method returns the array as a 642 /// StringRef. Otherwise, it asserts out. 643 StringRef getAsString() const { 644 assert(isString() && "Not a string"); 645 return getRawDataValues(); 646 } 647 648 /// If this array is isCString(), then this method returns the array (without 649 /// the trailing null byte) as a StringRef. Otherwise, it asserts out. 650 StringRef getAsCString() const { 651 assert(isCString() && "Isn't a C string"); 652 StringRef Str = getAsString(); 653 return Str.substr(0, Str.size() - 1); 654 } 655 656 /// Return the raw, underlying, bytes of this data. Note that this is an 657 /// extremely tricky thing to work with, as it exposes the host endianness of 658 /// the data elements. 659 StringRef getRawDataValues() const; 660 661 /// Methods for support type inquiry through isa, cast, and dyn_cast: 662 static bool classof(const Value *V) { 663 return V->getValueID() == ConstantDataArrayVal || 664 V->getValueID() == ConstantDataVectorVal; 665 } 666 667 private: 668 const char *getElementPointer(unsigned Elt) const; 669 }; 670 671 //===----------------------------------------------------------------------===// 672 /// An array constant whose element type is a simple 1/2/4/8-byte integer or 673 /// float/double, and whose elements are just simple data values 674 /// (i.e. ConstantInt/ConstantFP). This Constant node has no operands because it 675 /// stores all of the elements of the constant as densely packed data, instead 676 /// of as Value*'s. 677 class ConstantDataArray final : public ConstantDataSequential { 678 friend class ConstantDataSequential; 679 680 explicit ConstantDataArray(Type *ty, const char *Data) 681 : ConstantDataSequential(ty, ConstantDataArrayVal, Data) {} 682 683 public: 684 ConstantDataArray(const ConstantDataArray &) = delete; 685 686 /// get() constructor - Return a constant with array type with an element 687 /// count and element type matching the ArrayRef passed in. Note that this 688 /// can return a ConstantAggregateZero object. 689 template <typename ElementTy> 690 static Constant *get(LLVMContext &Context, ArrayRef<ElementTy> Elts) { 691 const char *Data = reinterpret_cast<const char *>(Elts.data()); 692 return getRaw(StringRef(Data, Elts.size() * sizeof(ElementTy)), Elts.size(), 693 Type::getScalarTy<ElementTy>(Context)); 694 } 695 696 /// get() constructor - ArrayTy needs to be compatible with 697 /// ArrayRef<ElementTy>. Calls get(LLVMContext, ArrayRef<ElementTy>). 698 template <typename ArrayTy> 699 static Constant *get(LLVMContext &Context, ArrayTy &Elts) { 700 return ConstantDataArray::get(Context, makeArrayRef(Elts)); 701 } 702 703 /// getRaw() constructor - Return a constant with array type with an element 704 /// count and element type matching the NumElements and ElementTy parameters 705 /// passed in. Note that this can return a ConstantAggregateZero object. 706 /// ElementTy must be one of i8/i16/i32/i64/half/bfloat/float/double. Data is 707 /// the buffer containing the elements. Be careful to make sure Data uses the 708 /// right endianness, the buffer will be used as-is. 709 static Constant *getRaw(StringRef Data, uint64_t NumElements, 710 Type *ElementTy) { 711 Type *Ty = ArrayType::get(ElementTy, NumElements); 712 return getImpl(Data, Ty); 713 } 714 715 /// getFP() constructors - Return a constant of array type with a float 716 /// element type taken from argument `ElementType', and count taken from 717 /// argument `Elts'. The amount of bits of the contained type must match the 718 /// number of bits of the type contained in the passed in ArrayRef. 719 /// (i.e. half or bfloat for 16bits, float for 32bits, double for 64bits) Note 720 /// that this can return a ConstantAggregateZero object. 721 static Constant *getFP(Type *ElementType, ArrayRef<uint16_t> Elts); 722 static Constant *getFP(Type *ElementType, ArrayRef<uint32_t> Elts); 723 static Constant *getFP(Type *ElementType, ArrayRef<uint64_t> Elts); 724 725 /// This method constructs a CDS and initializes it with a text string. 726 /// The default behavior (AddNull==true) causes a null terminator to 727 /// be placed at the end of the array (increasing the length of the string by 728 /// one more than the StringRef would normally indicate. Pass AddNull=false 729 /// to disable this behavior. 730 static Constant *getString(LLVMContext &Context, StringRef Initializer, 731 bool AddNull = true); 732 733 /// Specialize the getType() method to always return an ArrayType, 734 /// which reduces the amount of casting needed in parts of the compiler. 735 inline ArrayType *getType() const { 736 return cast<ArrayType>(Value::getType()); 737 } 738 739 /// Methods for support type inquiry through isa, cast, and dyn_cast: 740 static bool classof(const Value *V) { 741 return V->getValueID() == ConstantDataArrayVal; 742 } 743 }; 744 745 //===----------------------------------------------------------------------===// 746 /// A vector constant whose element type is a simple 1/2/4/8-byte integer or 747 /// float/double, and whose elements are just simple data values 748 /// (i.e. ConstantInt/ConstantFP). This Constant node has no operands because it 749 /// stores all of the elements of the constant as densely packed data, instead 750 /// of as Value*'s. 751 class ConstantDataVector final : public ConstantDataSequential { 752 friend class ConstantDataSequential; 753 754 explicit ConstantDataVector(Type *ty, const char *Data) 755 : ConstantDataSequential(ty, ConstantDataVectorVal, Data), 756 IsSplatSet(false) {} 757 // Cache whether or not the constant is a splat. 758 mutable bool IsSplatSet : 1; 759 mutable bool IsSplat : 1; 760 bool isSplatData() const; 761 762 public: 763 ConstantDataVector(const ConstantDataVector &) = delete; 764 765 /// get() constructors - Return a constant with vector type with an element 766 /// count and element type matching the ArrayRef passed in. Note that this 767 /// can return a ConstantAggregateZero object. 768 static Constant *get(LLVMContext &Context, ArrayRef<uint8_t> Elts); 769 static Constant *get(LLVMContext &Context, ArrayRef<uint16_t> Elts); 770 static Constant *get(LLVMContext &Context, ArrayRef<uint32_t> Elts); 771 static Constant *get(LLVMContext &Context, ArrayRef<uint64_t> Elts); 772 static Constant *get(LLVMContext &Context, ArrayRef<float> Elts); 773 static Constant *get(LLVMContext &Context, ArrayRef<double> Elts); 774 775 /// getRaw() constructor - Return a constant with vector type with an element 776 /// count and element type matching the NumElements and ElementTy parameters 777 /// passed in. Note that this can return a ConstantAggregateZero object. 778 /// ElementTy must be one of i8/i16/i32/i64/half/bfloat/float/double. Data is 779 /// the buffer containing the elements. Be careful to make sure Data uses the 780 /// right endianness, the buffer will be used as-is. 781 static Constant *getRaw(StringRef Data, uint64_t NumElements, 782 Type *ElementTy) { 783 Type *Ty = VectorType::get(ElementTy, ElementCount::getFixed(NumElements)); 784 return getImpl(Data, Ty); 785 } 786 787 /// getFP() constructors - Return a constant of vector type with a float 788 /// element type taken from argument `ElementType', and count taken from 789 /// argument `Elts'. The amount of bits of the contained type must match the 790 /// number of bits of the type contained in the passed in ArrayRef. 791 /// (i.e. half or bfloat for 16bits, float for 32bits, double for 64bits) Note 792 /// that this can return a ConstantAggregateZero object. 793 static Constant *getFP(Type *ElementType, ArrayRef<uint16_t> Elts); 794 static Constant *getFP(Type *ElementType, ArrayRef<uint32_t> Elts); 795 static Constant *getFP(Type *ElementType, ArrayRef<uint64_t> Elts); 796 797 /// Return a ConstantVector with the specified constant in each element. 798 /// The specified constant has to be a of a compatible type (i8/i16/ 799 /// i32/i64/half/bfloat/float/double) and must be a ConstantFP or ConstantInt. 800 static Constant *getSplat(unsigned NumElts, Constant *Elt); 801 802 /// Returns true if this is a splat constant, meaning that all elements have 803 /// the same value. 804 bool isSplat() const; 805 806 /// If this is a splat constant, meaning that all of the elements have the 807 /// same value, return that value. Otherwise return NULL. 808 Constant *getSplatValue() const; 809 810 /// Specialize the getType() method to always return a FixedVectorType, 811 /// which reduces the amount of casting needed in parts of the compiler. 812 inline FixedVectorType *getType() const { 813 return cast<FixedVectorType>(Value::getType()); 814 } 815 816 /// Methods for support type inquiry through isa, cast, and dyn_cast: 817 static bool classof(const Value *V) { 818 return V->getValueID() == ConstantDataVectorVal; 819 } 820 }; 821 822 //===----------------------------------------------------------------------===// 823 /// A constant token which is empty 824 /// 825 class ConstantTokenNone final : public ConstantData { 826 friend class Constant; 827 828 explicit ConstantTokenNone(LLVMContext &Context) 829 : ConstantData(Type::getTokenTy(Context), ConstantTokenNoneVal) {} 830 831 void destroyConstantImpl(); 832 833 public: 834 ConstantTokenNone(const ConstantTokenNone &) = delete; 835 836 /// Return the ConstantTokenNone. 837 static ConstantTokenNone *get(LLVMContext &Context); 838 839 /// Methods to support type inquiry through isa, cast, and dyn_cast. 840 static bool classof(const Value *V) { 841 return V->getValueID() == ConstantTokenNoneVal; 842 } 843 }; 844 845 /// The address of a basic block. 846 /// 847 class BlockAddress final : public Constant { 848 friend class Constant; 849 850 BlockAddress(Function *F, BasicBlock *BB); 851 852 void *operator new(size_t s) { return User::operator new(s, 2); } 853 854 void destroyConstantImpl(); 855 Value *handleOperandChangeImpl(Value *From, Value *To); 856 857 public: 858 /// Return a BlockAddress for the specified function and basic block. 859 static BlockAddress *get(Function *F, BasicBlock *BB); 860 861 /// Return a BlockAddress for the specified basic block. The basic 862 /// block must be embedded into a function. 863 static BlockAddress *get(BasicBlock *BB); 864 865 /// Lookup an existing \c BlockAddress constant for the given BasicBlock. 866 /// 867 /// \returns 0 if \c !BB->hasAddressTaken(), otherwise the \c BlockAddress. 868 static BlockAddress *lookup(const BasicBlock *BB); 869 870 /// Transparently provide more efficient getOperand methods. 871 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value); 872 873 Function *getFunction() const { return (Function *)Op<0>().get(); } 874 BasicBlock *getBasicBlock() const { return (BasicBlock *)Op<1>().get(); } 875 876 /// Methods for support type inquiry through isa, cast, and dyn_cast: 877 static bool classof(const Value *V) { 878 return V->getValueID() == BlockAddressVal; 879 } 880 }; 881 882 template <> 883 struct OperandTraits<BlockAddress> 884 : public FixedNumOperandTraits<BlockAddress, 2> {}; 885 886 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(BlockAddress, Value) 887 888 /// Wrapper for a function that represents a value that 889 /// functionally represents the original function. This can be a function, 890 /// global alias to a function, or an ifunc. 891 class DSOLocalEquivalent final : public Constant { 892 friend class Constant; 893 894 DSOLocalEquivalent(GlobalValue *GV); 895 896 void *operator new(size_t s) { return User::operator new(s, 1); } 897 898 void destroyConstantImpl(); 899 Value *handleOperandChangeImpl(Value *From, Value *To); 900 901 public: 902 /// Return a DSOLocalEquivalent for the specified global value. 903 static DSOLocalEquivalent *get(GlobalValue *GV); 904 905 /// Transparently provide more efficient getOperand methods. 906 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value); 907 908 GlobalValue *getGlobalValue() const { 909 return cast<GlobalValue>(Op<0>().get()); 910 } 911 912 /// Methods for support type inquiry through isa, cast, and dyn_cast: 913 static bool classof(const Value *V) { 914 return V->getValueID() == DSOLocalEquivalentVal; 915 } 916 }; 917 918 template <> 919 struct OperandTraits<DSOLocalEquivalent> 920 : public FixedNumOperandTraits<DSOLocalEquivalent, 1> {}; 921 922 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(DSOLocalEquivalent, Value) 923 924 //===----------------------------------------------------------------------===// 925 /// A constant value that is initialized with an expression using 926 /// other constant values. 927 /// 928 /// This class uses the standard Instruction opcodes to define the various 929 /// constant expressions. The Opcode field for the ConstantExpr class is 930 /// maintained in the Value::SubclassData field. 931 class ConstantExpr : public Constant { 932 friend struct ConstantExprKeyType; 933 friend class Constant; 934 935 void destroyConstantImpl(); 936 Value *handleOperandChangeImpl(Value *From, Value *To); 937 938 protected: 939 ConstantExpr(Type *ty, unsigned Opcode, Use *Ops, unsigned NumOps) 940 : Constant(ty, ConstantExprVal, Ops, NumOps) { 941 // Operation type (an Instruction opcode) is stored as the SubclassData. 942 setValueSubclassData(Opcode); 943 } 944 945 ~ConstantExpr() = default; 946 947 public: 948 // Static methods to construct a ConstantExpr of different kinds. Note that 949 // these methods may return a object that is not an instance of the 950 // ConstantExpr class, because they will attempt to fold the constant 951 // expression into something simpler if possible. 952 953 /// getAlignOf constant expr - computes the alignment of a type in a target 954 /// independent way (Note: the return type is an i64). 955 static Constant *getAlignOf(Type *Ty); 956 957 /// getSizeOf constant expr - computes the (alloc) size of a type (in 958 /// address-units, not bits) in a target independent way (Note: the return 959 /// type is an i64). 960 /// 961 static Constant *getSizeOf(Type *Ty); 962 963 /// getOffsetOf constant expr - computes the offset of a struct field in a 964 /// target independent way (Note: the return type is an i64). 965 /// 966 static Constant *getOffsetOf(StructType *STy, unsigned FieldNo); 967 968 /// getOffsetOf constant expr - This is a generalized form of getOffsetOf, 969 /// which supports any aggregate type, and any Constant index. 970 /// 971 static Constant *getOffsetOf(Type *Ty, Constant *FieldNo); 972 973 static Constant *getNeg(Constant *C, bool HasNUW = false, 974 bool HasNSW = false); 975 static Constant *getFNeg(Constant *C); 976 static Constant *getNot(Constant *C); 977 static Constant *getAdd(Constant *C1, Constant *C2, bool HasNUW = false, 978 bool HasNSW = false); 979 static Constant *getFAdd(Constant *C1, Constant *C2); 980 static Constant *getSub(Constant *C1, Constant *C2, bool HasNUW = false, 981 bool HasNSW = false); 982 static Constant *getFSub(Constant *C1, Constant *C2); 983 static Constant *getMul(Constant *C1, Constant *C2, bool HasNUW = false, 984 bool HasNSW = false); 985 static Constant *getFMul(Constant *C1, Constant *C2); 986 static Constant *getUDiv(Constant *C1, Constant *C2, bool isExact = false); 987 static Constant *getSDiv(Constant *C1, Constant *C2, bool isExact = false); 988 static Constant *getFDiv(Constant *C1, Constant *C2); 989 static Constant *getURem(Constant *C1, Constant *C2); 990 static Constant *getSRem(Constant *C1, Constant *C2); 991 static Constant *getFRem(Constant *C1, Constant *C2); 992 static Constant *getAnd(Constant *C1, Constant *C2); 993 static Constant *getOr(Constant *C1, Constant *C2); 994 static Constant *getXor(Constant *C1, Constant *C2); 995 static Constant *getUMin(Constant *C1, Constant *C2); 996 static Constant *getShl(Constant *C1, Constant *C2, bool HasNUW = false, 997 bool HasNSW = false); 998 static Constant *getLShr(Constant *C1, Constant *C2, bool isExact = false); 999 static Constant *getAShr(Constant *C1, Constant *C2, bool isExact = false); 1000 static Constant *getTrunc(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1001 static Constant *getSExt(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1002 static Constant *getZExt(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1003 static Constant *getFPTrunc(Constant *C, Type *Ty, 1004 bool OnlyIfReduced = false); 1005 static Constant *getFPExtend(Constant *C, Type *Ty, 1006 bool OnlyIfReduced = false); 1007 static Constant *getUIToFP(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1008 static Constant *getSIToFP(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1009 static Constant *getFPToUI(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1010 static Constant *getFPToSI(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1011 static Constant *getPtrToInt(Constant *C, Type *Ty, 1012 bool OnlyIfReduced = false); 1013 static Constant *getIntToPtr(Constant *C, Type *Ty, 1014 bool OnlyIfReduced = false); 1015 static Constant *getBitCast(Constant *C, Type *Ty, 1016 bool OnlyIfReduced = false); 1017 static Constant *getAddrSpaceCast(Constant *C, Type *Ty, 1018 bool OnlyIfReduced = false); 1019 1020 static Constant *getNSWNeg(Constant *C) { return getNeg(C, false, true); } 1021 static Constant *getNUWNeg(Constant *C) { return getNeg(C, true, false); } 1022 1023 static Constant *getNSWAdd(Constant *C1, Constant *C2) { 1024 return getAdd(C1, C2, false, true); 1025 } 1026 1027 static Constant *getNUWAdd(Constant *C1, Constant *C2) { 1028 return getAdd(C1, C2, true, false); 1029 } 1030 1031 static Constant *getNSWSub(Constant *C1, Constant *C2) { 1032 return getSub(C1, C2, false, true); 1033 } 1034 1035 static Constant *getNUWSub(Constant *C1, Constant *C2) { 1036 return getSub(C1, C2, true, false); 1037 } 1038 1039 static Constant *getNSWMul(Constant *C1, Constant *C2) { 1040 return getMul(C1, C2, false, true); 1041 } 1042 1043 static Constant *getNUWMul(Constant *C1, Constant *C2) { 1044 return getMul(C1, C2, true, false); 1045 } 1046 1047 static Constant *getNSWShl(Constant *C1, Constant *C2) { 1048 return getShl(C1, C2, false, true); 1049 } 1050 1051 static Constant *getNUWShl(Constant *C1, Constant *C2) { 1052 return getShl(C1, C2, true, false); 1053 } 1054 1055 static Constant *getExactSDiv(Constant *C1, Constant *C2) { 1056 return getSDiv(C1, C2, true); 1057 } 1058 1059 static Constant *getExactUDiv(Constant *C1, Constant *C2) { 1060 return getUDiv(C1, C2, true); 1061 } 1062 1063 static Constant *getExactAShr(Constant *C1, Constant *C2) { 1064 return getAShr(C1, C2, true); 1065 } 1066 1067 static Constant *getExactLShr(Constant *C1, Constant *C2) { 1068 return getLShr(C1, C2, true); 1069 } 1070 1071 /// If C is a scalar/fixed width vector of known powers of 2, then this 1072 /// function returns a new scalar/fixed width vector obtained from logBase2 1073 /// of C. Undef vector elements are set to zero. 1074 /// Return a null pointer otherwise. 1075 static Constant *getExactLogBase2(Constant *C); 1076 1077 /// Return the identity constant for a binary opcode. 1078 /// The identity constant C is defined as X op C = X and C op X = X for every 1079 /// X when the binary operation is commutative. If the binop is not 1080 /// commutative, callers can acquire the operand 1 identity constant by 1081 /// setting AllowRHSConstant to true. For example, any shift has a zero 1082 /// identity constant for operand 1: X shift 0 = X. 1083 /// Return nullptr if the operator does not have an identity constant. 1084 static Constant *getBinOpIdentity(unsigned Opcode, Type *Ty, 1085 bool AllowRHSConstant = false); 1086 1087 /// Return the absorbing element for the given binary 1088 /// operation, i.e. a constant C such that X op C = C and C op X = C for 1089 /// every X. For example, this returns zero for integer multiplication. 1090 /// It returns null if the operator doesn't have an absorbing element. 1091 static Constant *getBinOpAbsorber(unsigned Opcode, Type *Ty); 1092 1093 /// Transparently provide more efficient getOperand methods. 1094 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant); 1095 1096 /// Convenience function for getting a Cast operation. 1097 /// 1098 /// \param ops The opcode for the conversion 1099 /// \param C The constant to be converted 1100 /// \param Ty The type to which the constant is converted 1101 /// \param OnlyIfReduced see \a getWithOperands() docs. 1102 static Constant *getCast(unsigned ops, Constant *C, Type *Ty, 1103 bool OnlyIfReduced = false); 1104 1105 // Create a ZExt or BitCast cast constant expression 1106 static Constant * 1107 getZExtOrBitCast(Constant *C, ///< The constant to zext or bitcast 1108 Type *Ty ///< The type to zext or bitcast C to 1109 ); 1110 1111 // Create a SExt or BitCast cast constant expression 1112 static Constant * 1113 getSExtOrBitCast(Constant *C, ///< The constant to sext or bitcast 1114 Type *Ty ///< The type to sext or bitcast C to 1115 ); 1116 1117 // Create a Trunc or BitCast cast constant expression 1118 static Constant * 1119 getTruncOrBitCast(Constant *C, ///< The constant to trunc or bitcast 1120 Type *Ty ///< The type to trunc or bitcast C to 1121 ); 1122 1123 /// Create a BitCast, AddrSpaceCast, or a PtrToInt cast constant 1124 /// expression. 1125 static Constant * 1126 getPointerCast(Constant *C, ///< The pointer value to be casted (operand 0) 1127 Type *Ty ///< The type to which cast should be made 1128 ); 1129 1130 /// Create a BitCast or AddrSpaceCast for a pointer type depending on 1131 /// the address space. 1132 static Constant *getPointerBitCastOrAddrSpaceCast( 1133 Constant *C, ///< The constant to addrspacecast or bitcast 1134 Type *Ty ///< The type to bitcast or addrspacecast C to 1135 ); 1136 1137 /// Create a ZExt, Bitcast or Trunc for integer -> integer casts 1138 static Constant * 1139 getIntegerCast(Constant *C, ///< The integer constant to be casted 1140 Type *Ty, ///< The integer type to cast to 1141 bool IsSigned ///< Whether C should be treated as signed or not 1142 ); 1143 1144 /// Create a FPExt, Bitcast or FPTrunc for fp -> fp casts 1145 static Constant *getFPCast(Constant *C, ///< The integer constant to be casted 1146 Type *Ty ///< The integer type to cast to 1147 ); 1148 1149 /// Return true if this is a convert constant expression 1150 bool isCast() const; 1151 1152 /// Return true if this is a compare constant expression 1153 bool isCompare() const; 1154 1155 /// Return true if this is an insertvalue or extractvalue expression, 1156 /// and the getIndices() method may be used. 1157 bool hasIndices() const; 1158 1159 /// Return true if this is a getelementptr expression and all 1160 /// the index operands are compile-time known integers within the 1161 /// corresponding notional static array extents. Note that this is 1162 /// not equivalant to, a subset of, or a superset of the "inbounds" 1163 /// property. 1164 bool isGEPWithNoNotionalOverIndexing() const; 1165 1166 /// Select constant expr 1167 /// 1168 /// \param OnlyIfReducedTy see \a getWithOperands() docs. 1169 static Constant *getSelect(Constant *C, Constant *V1, Constant *V2, 1170 Type *OnlyIfReducedTy = nullptr); 1171 1172 /// get - Return a unary operator constant expression, 1173 /// folding if possible. 1174 /// 1175 /// \param OnlyIfReducedTy see \a getWithOperands() docs. 1176 static Constant *get(unsigned Opcode, Constant *C1, unsigned Flags = 0, 1177 Type *OnlyIfReducedTy = nullptr); 1178 1179 /// get - Return a binary or shift operator constant expression, 1180 /// folding if possible. 1181 /// 1182 /// \param OnlyIfReducedTy see \a getWithOperands() docs. 1183 static Constant *get(unsigned Opcode, Constant *C1, Constant *C2, 1184 unsigned Flags = 0, Type *OnlyIfReducedTy = nullptr); 1185 1186 /// Return an ICmp or FCmp comparison operator constant expression. 1187 /// 1188 /// \param OnlyIfReduced see \a getWithOperands() docs. 1189 static Constant *getCompare(unsigned short pred, Constant *C1, Constant *C2, 1190 bool OnlyIfReduced = false); 1191 1192 /// get* - Return some common constants without having to 1193 /// specify the full Instruction::OPCODE identifier. 1194 /// 1195 static Constant *getICmp(unsigned short pred, Constant *LHS, Constant *RHS, 1196 bool OnlyIfReduced = false); 1197 static Constant *getFCmp(unsigned short pred, Constant *LHS, Constant *RHS, 1198 bool OnlyIfReduced = false); 1199 1200 /// Getelementptr form. Value* is only accepted for convenience; 1201 /// all elements must be Constants. 1202 /// 1203 /// \param InRangeIndex the inrange index if present or None. 1204 /// \param OnlyIfReducedTy see \a getWithOperands() docs. 1205 static Constant *getGetElementPtr(Type *Ty, Constant *C, 1206 ArrayRef<Constant *> IdxList, 1207 bool InBounds = false, 1208 Optional<unsigned> InRangeIndex = None, 1209 Type *OnlyIfReducedTy = nullptr) { 1210 return getGetElementPtr( 1211 Ty, C, makeArrayRef((Value *const *)IdxList.data(), IdxList.size()), 1212 InBounds, InRangeIndex, OnlyIfReducedTy); 1213 } 1214 static Constant *getGetElementPtr(Type *Ty, Constant *C, Constant *Idx, 1215 bool InBounds = false, 1216 Optional<unsigned> InRangeIndex = None, 1217 Type *OnlyIfReducedTy = nullptr) { 1218 // This form of the function only exists to avoid ambiguous overload 1219 // warnings about whether to convert Idx to ArrayRef<Constant *> or 1220 // ArrayRef<Value *>. 1221 return getGetElementPtr(Ty, C, cast<Value>(Idx), InBounds, InRangeIndex, 1222 OnlyIfReducedTy); 1223 } 1224 static Constant *getGetElementPtr(Type *Ty, Constant *C, 1225 ArrayRef<Value *> IdxList, 1226 bool InBounds = false, 1227 Optional<unsigned> InRangeIndex = None, 1228 Type *OnlyIfReducedTy = nullptr); 1229 1230 /// Create an "inbounds" getelementptr. See the documentation for the 1231 /// "inbounds" flag in LangRef.html for details. 1232 static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C, 1233 ArrayRef<Constant *> IdxList) { 1234 return getGetElementPtr(Ty, C, IdxList, true); 1235 } 1236 static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C, 1237 Constant *Idx) { 1238 // This form of the function only exists to avoid ambiguous overload 1239 // warnings about whether to convert Idx to ArrayRef<Constant *> or 1240 // ArrayRef<Value *>. 1241 return getGetElementPtr(Ty, C, Idx, true); 1242 } 1243 static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C, 1244 ArrayRef<Value *> IdxList) { 1245 return getGetElementPtr(Ty, C, IdxList, true); 1246 } 1247 1248 static Constant *getExtractElement(Constant *Vec, Constant *Idx, 1249 Type *OnlyIfReducedTy = nullptr); 1250 static Constant *getInsertElement(Constant *Vec, Constant *Elt, Constant *Idx, 1251 Type *OnlyIfReducedTy = nullptr); 1252 static Constant *getShuffleVector(Constant *V1, Constant *V2, 1253 ArrayRef<int> Mask, 1254 Type *OnlyIfReducedTy = nullptr); 1255 static Constant *getExtractValue(Constant *Agg, ArrayRef<unsigned> Idxs, 1256 Type *OnlyIfReducedTy = nullptr); 1257 static Constant *getInsertValue(Constant *Agg, Constant *Val, 1258 ArrayRef<unsigned> Idxs, 1259 Type *OnlyIfReducedTy = nullptr); 1260 1261 /// Return the opcode at the root of this constant expression 1262 unsigned getOpcode() const { return getSubclassDataFromValue(); } 1263 1264 /// Return the ICMP or FCMP predicate value. Assert if this is not an ICMP or 1265 /// FCMP constant expression. 1266 unsigned getPredicate() const; 1267 1268 /// Assert that this is an insertvalue or exactvalue 1269 /// expression and return the list of indices. 1270 ArrayRef<unsigned> getIndices() const; 1271 1272 /// Assert that this is a shufflevector and return the mask. See class 1273 /// ShuffleVectorInst for a description of the mask representation. 1274 ArrayRef<int> getShuffleMask() const; 1275 1276 /// Assert that this is a shufflevector and return the mask. 1277 /// 1278 /// TODO: This is a temporary hack until we update the bitcode format for 1279 /// shufflevector. 1280 Constant *getShuffleMaskForBitcode() const; 1281 1282 /// Return a string representation for an opcode. 1283 const char *getOpcodeName() const; 1284 1285 /// Return a constant expression identical to this one, but with the specified 1286 /// operand set to the specified value. 1287 Constant *getWithOperandReplaced(unsigned OpNo, Constant *Op) const; 1288 1289 /// This returns the current constant expression with the operands replaced 1290 /// with the specified values. The specified array must have the same number 1291 /// of operands as our current one. 1292 Constant *getWithOperands(ArrayRef<Constant *> Ops) const { 1293 return getWithOperands(Ops, getType()); 1294 } 1295 1296 /// Get the current expression with the operands replaced. 1297 /// 1298 /// Return the current constant expression with the operands replaced with \c 1299 /// Ops and the type with \c Ty. The new operands must have the same number 1300 /// as the current ones. 1301 /// 1302 /// If \c OnlyIfReduced is \c true, nullptr will be returned unless something 1303 /// gets constant-folded, the type changes, or the expression is otherwise 1304 /// canonicalized. This parameter should almost always be \c false. 1305 Constant *getWithOperands(ArrayRef<Constant *> Ops, Type *Ty, 1306 bool OnlyIfReduced = false, 1307 Type *SrcTy = nullptr) const; 1308 1309 /// Returns an Instruction which implements the same operation as this 1310 /// ConstantExpr. The instruction is not linked to any basic block. 1311 /// 1312 /// A better approach to this could be to have a constructor for Instruction 1313 /// which would take a ConstantExpr parameter, but that would have spread 1314 /// implementation details of ConstantExpr outside of Constants.cpp, which 1315 /// would make it harder to remove ConstantExprs altogether. 1316 Instruction *getAsInstruction() const; 1317 1318 /// Methods for support type inquiry through isa, cast, and dyn_cast: 1319 static bool classof(const Value *V) { 1320 return V->getValueID() == ConstantExprVal; 1321 } 1322 1323 private: 1324 // Shadow Value::setValueSubclassData with a private forwarding method so that 1325 // subclasses cannot accidentally use it. 1326 void setValueSubclassData(unsigned short D) { 1327 Value::setValueSubclassData(D); 1328 } 1329 }; 1330 1331 template <> 1332 struct OperandTraits<ConstantExpr> 1333 : public VariadicOperandTraits<ConstantExpr, 1> {}; 1334 1335 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantExpr, Constant) 1336 1337 //===----------------------------------------------------------------------===// 1338 /// 'undef' values are things that do not have specified contents. 1339 /// These are used for a variety of purposes, including global variable 1340 /// initializers and operands to instructions. 'undef' values can occur with 1341 /// any first-class type. 1342 /// 1343 /// Undef values aren't exactly constants; if they have multiple uses, they 1344 /// can appear to have different bit patterns at each use. See 1345 /// LangRef.html#undefvalues for details. 1346 /// 1347 class UndefValue : public ConstantData { 1348 friend class Constant; 1349 1350 explicit UndefValue(Type *T) : ConstantData(T, UndefValueVal) {} 1351 1352 void destroyConstantImpl(); 1353 1354 protected: 1355 explicit UndefValue(Type *T, ValueTy vty) : ConstantData(T, vty) {} 1356 1357 public: 1358 UndefValue(const UndefValue &) = delete; 1359 1360 /// Static factory methods - Return an 'undef' object of the specified type. 1361 static UndefValue *get(Type *T); 1362 1363 /// If this Undef has array or vector type, return a undef with the right 1364 /// element type. 1365 UndefValue *getSequentialElement() const; 1366 1367 /// If this undef has struct type, return a undef with the right element type 1368 /// for the specified element. 1369 UndefValue *getStructElement(unsigned Elt) const; 1370 1371 /// Return an undef of the right value for the specified GEP index if we can, 1372 /// otherwise return null (e.g. if C is a ConstantExpr). 1373 UndefValue *getElementValue(Constant *C) const; 1374 1375 /// Return an undef of the right value for the specified GEP index. 1376 UndefValue *getElementValue(unsigned Idx) const; 1377 1378 /// Return the number of elements in the array, vector, or struct. 1379 unsigned getNumElements() const; 1380 1381 /// Methods for support type inquiry through isa, cast, and dyn_cast: 1382 static bool classof(const Value *V) { 1383 return V->getValueID() == UndefValueVal || 1384 V->getValueID() == PoisonValueVal; 1385 } 1386 }; 1387 1388 //===----------------------------------------------------------------------===// 1389 /// In order to facilitate speculative execution, many instructions do not 1390 /// invoke immediate undefined behavior when provided with illegal operands, 1391 /// and return a poison value instead. 1392 /// 1393 /// see LangRef.html#poisonvalues for details. 1394 /// 1395 class PoisonValue final : public UndefValue { 1396 friend class Constant; 1397 1398 explicit PoisonValue(Type *T) : UndefValue(T, PoisonValueVal) {} 1399 1400 void destroyConstantImpl(); 1401 1402 public: 1403 PoisonValue(const PoisonValue &) = delete; 1404 1405 /// Static factory methods - Return an 'poison' object of the specified type. 1406 static PoisonValue *get(Type *T); 1407 1408 /// If this poison has array or vector type, return a poison with the right 1409 /// element type. 1410 PoisonValue *getSequentialElement() const; 1411 1412 /// If this poison has struct type, return a poison with the right element 1413 /// type for the specified element. 1414 PoisonValue *getStructElement(unsigned Elt) const; 1415 1416 /// Return an poison of the right value for the specified GEP index if we can, 1417 /// otherwise return null (e.g. if C is a ConstantExpr). 1418 PoisonValue *getElementValue(Constant *C) const; 1419 1420 /// Return an poison of the right value for the specified GEP index. 1421 PoisonValue *getElementValue(unsigned Idx) const; 1422 1423 /// Methods for support type inquiry through isa, cast, and dyn_cast: 1424 static bool classof(const Value *V) { 1425 return V->getValueID() == PoisonValueVal; 1426 } 1427 }; 1428 1429 } // end namespace llvm 1430 1431 #endif // LLVM_IR_CONSTANTS_H 1432