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 54 Value *handleOperandChangeImpl(Value *From, Value *To) { 55 llvm_unreachable("Constant data does not have operands!"); 56 } 57 58 protected: 59 explicit ConstantData(Type *Ty, ValueTy VT) : Constant(Ty, VT, nullptr, 0) {} 60 61 void *operator new(size_t S) { return User::operator new(S, 0); } 62 63 public: 64 void operator delete(void *Ptr) { User::operator delete(Ptr); } 65 66 ConstantData(const ConstantData &) = delete; 67 68 /// Methods to support type inquiry through isa, cast, and dyn_cast. 69 static bool classof(const Value *V) { 70 return V->getValueID() >= ConstantDataFirstVal && 71 V->getValueID() <= ConstantDataLastVal; 72 } 73 }; 74 75 //===----------------------------------------------------------------------===// 76 /// This is the shared class of boolean and integer constants. This class 77 /// represents both boolean and integral constants. 78 /// Class for constant integers. 79 class ConstantInt final : public ConstantData { 80 friend class Constant; 81 82 APInt Val; 83 84 ConstantInt(IntegerType *Ty, const APInt &V); 85 86 void destroyConstantImpl(); 87 88 public: 89 ConstantInt(const ConstantInt &) = delete; 90 91 static ConstantInt *getTrue(LLVMContext &Context); 92 static ConstantInt *getFalse(LLVMContext &Context); 93 static ConstantInt *getBool(LLVMContext &Context, bool V); 94 static Constant *getTrue(Type *Ty); 95 static Constant *getFalse(Type *Ty); 96 static Constant *getBool(Type *Ty, bool V); 97 98 /// If Ty is a vector type, return a Constant with a splat of the given 99 /// value. Otherwise return a ConstantInt for the given value. 100 static Constant *get(Type *Ty, uint64_t V, bool IsSigned = false); 101 102 /// Return a ConstantInt with the specified integer value for the specified 103 /// type. If the type is wider than 64 bits, the value will be zero-extended 104 /// to fit the type, unless IsSigned is true, in which case the value will 105 /// be interpreted as a 64-bit signed integer and sign-extended to fit 106 /// the type. 107 /// Get a ConstantInt for a specific value. 108 static ConstantInt *get(IntegerType *Ty, uint64_t V, bool IsSigned = false); 109 110 /// Return a ConstantInt with the specified value for the specified type. The 111 /// value V will be canonicalized to a an unsigned APInt. Accessing it with 112 /// either getSExtValue() or getZExtValue() will yield a correctly sized and 113 /// signed value for the type Ty. 114 /// Get a ConstantInt for a specific signed value. 115 static ConstantInt *getSigned(IntegerType *Ty, int64_t V); 116 static Constant *getSigned(Type *Ty, int64_t V); 117 118 /// Return a ConstantInt with the specified value and an implied Type. The 119 /// type is the integer type that corresponds to the bit width of the value. 120 static ConstantInt *get(LLVMContext &Context, const APInt &V); 121 122 /// Return a ConstantInt constructed from the string strStart with the given 123 /// radix. 124 static ConstantInt *get(IntegerType *Ty, StringRef Str, uint8_t Radix); 125 126 /// If Ty is a vector type, return a Constant with a splat of the given 127 /// value. Otherwise return a ConstantInt for the given value. 128 static Constant *get(Type *Ty, const APInt &V); 129 130 /// Return the constant as an APInt value reference. This allows clients to 131 /// obtain a full-precision copy of the value. 132 /// Return the constant's value. 133 inline const APInt &getValue() const { return Val; } 134 135 /// getBitWidth - Return the bitwidth of this constant. 136 unsigned getBitWidth() const { return Val.getBitWidth(); } 137 138 /// Return the constant as a 64-bit unsigned integer value after it 139 /// has been zero extended as appropriate for the type of this constant. Note 140 /// that this method can assert if the value does not fit in 64 bits. 141 /// Return the zero extended value. 142 inline uint64_t getZExtValue() const { return Val.getZExtValue(); } 143 144 /// Return the constant as a 64-bit integer value after it has been sign 145 /// extended as appropriate for the type of this constant. Note that 146 /// this method can assert if the value does not fit in 64 bits. 147 /// Return the sign extended value. 148 inline int64_t getSExtValue() const { return Val.getSExtValue(); } 149 150 /// Return the constant as an llvm::MaybeAlign. 151 /// Note that this method can assert if the value does not fit in 64 bits or 152 /// is not a power of two. 153 inline MaybeAlign getMaybeAlignValue() const { 154 return MaybeAlign(getZExtValue()); 155 } 156 157 /// Return the constant as an llvm::Align, interpreting `0` as `Align(1)`. 158 /// Note that this method can assert if the value does not fit in 64 bits or 159 /// is not a power of two. 160 inline Align getAlignValue() const { 161 return getMaybeAlignValue().valueOrOne(); 162 } 163 164 /// A helper method that can be used to determine if the constant contained 165 /// within is equal to a constant. This only works for very small values, 166 /// because this is all that can be represented with all types. 167 /// Determine if this constant's value is same as an unsigned char. 168 bool equalsInt(uint64_t V) const { return Val == V; } 169 170 /// getType - Specialize the getType() method to always return an IntegerType, 171 /// which reduces the amount of casting needed in parts of the compiler. 172 /// 173 inline IntegerType *getType() const { 174 return cast<IntegerType>(Value::getType()); 175 } 176 177 /// This static method returns true if the type Ty is big enough to 178 /// represent the value V. This can be used to avoid having the get method 179 /// assert when V is larger than Ty can represent. Note that there are two 180 /// versions of this method, one for unsigned and one for signed integers. 181 /// Although ConstantInt canonicalizes everything to an unsigned integer, 182 /// the signed version avoids callers having to convert a signed quantity 183 /// to the appropriate unsigned type before calling the method. 184 /// @returns true if V is a valid value for type Ty 185 /// Determine if the value is in range for the given type. 186 static bool isValueValidForType(Type *Ty, uint64_t V); 187 static bool isValueValidForType(Type *Ty, int64_t V); 188 189 bool isNegative() const { return Val.isNegative(); } 190 191 /// This is just a convenience method to make client code smaller for a 192 /// common code. It also correctly performs the comparison without the 193 /// potential for an assertion from getZExtValue(). 194 bool isZero() const { return Val.isZero(); } 195 196 /// This is just a convenience method to make client code smaller for a 197 /// common case. It also correctly performs the comparison without the 198 /// potential for an assertion from getZExtValue(). 199 /// Determine if the value is one. 200 bool isOne() const { return Val.isOne(); } 201 202 /// This function will return true iff every bit in this constant is set 203 /// to true. 204 /// @returns true iff this constant's bits are all set to true. 205 /// Determine if the value is all ones. 206 bool isMinusOne() const { return Val.isAllOnes(); } 207 208 /// This function will return true iff this constant represents the largest 209 /// value that may be represented by the constant's type. 210 /// @returns true iff this is the largest value that may be represented 211 /// by this type. 212 /// Determine if the value is maximal. 213 bool isMaxValue(bool IsSigned) const { 214 if (IsSigned) 215 return Val.isMaxSignedValue(); 216 else 217 return Val.isMaxValue(); 218 } 219 220 /// This function will return true iff this constant represents the smallest 221 /// value that may be represented by this constant's type. 222 /// @returns true if this is the smallest value that may be represented by 223 /// this type. 224 /// Determine if the value is minimal. 225 bool isMinValue(bool IsSigned) const { 226 if (IsSigned) 227 return Val.isMinSignedValue(); 228 else 229 return Val.isMinValue(); 230 } 231 232 /// This function will return true iff this constant represents a value with 233 /// active bits bigger than 64 bits or a value greater than the given uint64_t 234 /// value. 235 /// @returns true iff this constant is greater or equal to the given number. 236 /// Determine if the value is greater or equal to the given number. 237 bool uge(uint64_t Num) const { return Val.uge(Num); } 238 239 /// getLimitedValue - If the value is smaller than the specified limit, 240 /// return it, otherwise return the limit value. This causes the value 241 /// to saturate to the limit. 242 /// @returns the min of the value of the constant and the specified value 243 /// Get the constant's value with a saturation limit 244 uint64_t getLimitedValue(uint64_t Limit = ~0ULL) const { 245 return Val.getLimitedValue(Limit); 246 } 247 248 /// Methods to support type inquiry through isa, cast, and dyn_cast. 249 static bool classof(const Value *V) { 250 return V->getValueID() == ConstantIntVal; 251 } 252 }; 253 254 //===----------------------------------------------------------------------===// 255 /// ConstantFP - Floating Point Values [float, double] 256 /// 257 class ConstantFP final : public ConstantData { 258 friend class Constant; 259 260 APFloat Val; 261 262 ConstantFP(Type *Ty, const APFloat &V); 263 264 void destroyConstantImpl(); 265 266 public: 267 ConstantFP(const ConstantFP &) = delete; 268 269 /// Floating point negation must be implemented with f(x) = -0.0 - x. This 270 /// method returns the negative zero constant for floating point or vector 271 /// floating point types; for all other types, it returns the null value. 272 static Constant *getZeroValueForNegation(Type *Ty); 273 274 /// This returns a ConstantFP, or a vector containing a splat of a ConstantFP, 275 /// for the specified value in the specified type. This should only be used 276 /// for simple constant values like 2.0/1.0 etc, that are known-valid both as 277 /// host double and as the target format. 278 static Constant *get(Type *Ty, double V); 279 280 /// If Ty is a vector type, return a Constant with a splat of the given 281 /// value. Otherwise return a ConstantFP for the given value. 282 static Constant *get(Type *Ty, const APFloat &V); 283 284 static Constant *get(Type *Ty, StringRef Str); 285 static ConstantFP *get(LLVMContext &Context, const APFloat &V); 286 static Constant *getNaN(Type *Ty, bool Negative = false, 287 uint64_t Payload = 0); 288 static Constant *getQNaN(Type *Ty, bool Negative = false, 289 APInt *Payload = nullptr); 290 static Constant *getSNaN(Type *Ty, bool Negative = false, 291 APInt *Payload = nullptr); 292 static Constant *getZero(Type *Ty, bool Negative = false); 293 static Constant *getNegativeZero(Type *Ty) { return getZero(Ty, true); } 294 static Constant *getInfinity(Type *Ty, bool Negative = false); 295 296 /// Return true if Ty is big enough to represent V. 297 static bool isValueValidForType(Type *Ty, const APFloat &V); 298 inline const APFloat &getValueAPF() const { return Val; } 299 inline const APFloat &getValue() const { return Val; } 300 301 /// Return true if the value is positive or negative zero. 302 bool isZero() const { return Val.isZero(); } 303 304 /// Return true if the sign bit is set. 305 bool isNegative() const { return Val.isNegative(); } 306 307 /// Return true if the value is infinity 308 bool isInfinity() const { return Val.isInfinity(); } 309 310 /// Return true if the value is a NaN. 311 bool isNaN() const { return Val.isNaN(); } 312 313 /// We don't rely on operator== working on double values, as it returns true 314 /// for things that are clearly not equal, like -0.0 and 0.0. 315 /// As such, this method can be used to do an exact bit-for-bit comparison of 316 /// two floating point values. The version with a double operand is retained 317 /// because it's so convenient to write isExactlyValue(2.0), but please use 318 /// it only for simple constants. 319 bool isExactlyValue(const APFloat &V) const; 320 321 bool isExactlyValue(double V) const { 322 bool ignored; 323 APFloat FV(V); 324 FV.convert(Val.getSemantics(), APFloat::rmNearestTiesToEven, &ignored); 325 return isExactlyValue(FV); 326 } 327 328 /// Methods for support type inquiry through isa, cast, and dyn_cast: 329 static bool classof(const Value *V) { 330 return V->getValueID() == ConstantFPVal; 331 } 332 }; 333 334 //===----------------------------------------------------------------------===// 335 /// All zero aggregate value 336 /// 337 class ConstantAggregateZero final : public ConstantData { 338 friend class Constant; 339 340 explicit ConstantAggregateZero(Type *Ty) 341 : ConstantData(Ty, ConstantAggregateZeroVal) {} 342 343 void destroyConstantImpl(); 344 345 public: 346 ConstantAggregateZero(const ConstantAggregateZero &) = delete; 347 348 static ConstantAggregateZero *get(Type *Ty); 349 350 /// If this CAZ has array or vector type, return a zero with the right element 351 /// type. 352 Constant *getSequentialElement() const; 353 354 /// If this CAZ has struct type, return a zero with the right element type for 355 /// the specified element. 356 Constant *getStructElement(unsigned Elt) const; 357 358 /// Return a zero of the right value for the specified GEP index if we can, 359 /// otherwise return null (e.g. if C is a ConstantExpr). 360 Constant *getElementValue(Constant *C) const; 361 362 /// Return a zero of the right value for the specified GEP index. 363 Constant *getElementValue(unsigned Idx) const; 364 365 /// Return the number of elements in the array, vector, or struct. 366 ElementCount getElementCount() const; 367 368 /// Methods for support type inquiry through isa, cast, and dyn_cast: 369 /// 370 static bool classof(const Value *V) { 371 return V->getValueID() == ConstantAggregateZeroVal; 372 } 373 }; 374 375 /// Base class for aggregate constants (with operands). 376 /// 377 /// These constants are aggregates of other constants, which are stored as 378 /// operands. 379 /// 380 /// Subclasses are \a ConstantStruct, \a ConstantArray, and \a 381 /// ConstantVector. 382 /// 383 /// \note Some subclasses of \a ConstantData are semantically aggregates -- 384 /// such as \a ConstantDataArray -- but are not subclasses of this because they 385 /// use operands. 386 class ConstantAggregate : public Constant { 387 protected: 388 ConstantAggregate(Type *T, ValueTy VT, ArrayRef<Constant *> V); 389 390 public: 391 /// Transparently provide more efficient getOperand methods. 392 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant); 393 394 /// Methods for support type inquiry through isa, cast, and dyn_cast: 395 static bool classof(const Value *V) { 396 return V->getValueID() >= ConstantAggregateFirstVal && 397 V->getValueID() <= ConstantAggregateLastVal; 398 } 399 }; 400 401 template <> 402 struct OperandTraits<ConstantAggregate> 403 : public VariadicOperandTraits<ConstantAggregate> {}; 404 405 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantAggregate, Constant) 406 407 //===----------------------------------------------------------------------===// 408 /// ConstantArray - Constant Array Declarations 409 /// 410 class ConstantArray final : public ConstantAggregate { 411 friend struct ConstantAggrKeyType<ConstantArray>; 412 friend class Constant; 413 414 ConstantArray(ArrayType *T, ArrayRef<Constant *> Val); 415 416 void destroyConstantImpl(); 417 Value *handleOperandChangeImpl(Value *From, Value *To); 418 419 public: 420 // ConstantArray accessors 421 static Constant *get(ArrayType *T, ArrayRef<Constant *> V); 422 423 private: 424 static Constant *getImpl(ArrayType *T, ArrayRef<Constant *> V); 425 426 public: 427 /// Specialize the getType() method to always return an ArrayType, 428 /// which reduces the amount of casting needed in parts of the compiler. 429 inline ArrayType *getType() const { 430 return cast<ArrayType>(Value::getType()); 431 } 432 433 /// Methods for support type inquiry through isa, cast, and dyn_cast: 434 static bool classof(const Value *V) { 435 return V->getValueID() == ConstantArrayVal; 436 } 437 }; 438 439 //===----------------------------------------------------------------------===// 440 // Constant Struct Declarations 441 // 442 class ConstantStruct final : public ConstantAggregate { 443 friend struct ConstantAggrKeyType<ConstantStruct>; 444 friend class Constant; 445 446 ConstantStruct(StructType *T, ArrayRef<Constant *> Val); 447 448 void destroyConstantImpl(); 449 Value *handleOperandChangeImpl(Value *From, Value *To); 450 451 public: 452 // ConstantStruct accessors 453 static Constant *get(StructType *T, ArrayRef<Constant *> V); 454 455 template <typename... Csts> 456 static std::enable_if_t<are_base_of<Constant, Csts...>::value, Constant *> 457 get(StructType *T, Csts *...Vs) { 458 return get(T, ArrayRef<Constant *>({Vs...})); 459 } 460 461 /// Return an anonymous struct that has the specified elements. 462 /// If the struct is possibly empty, then you must specify a context. 463 static Constant *getAnon(ArrayRef<Constant *> V, bool Packed = false) { 464 return get(getTypeForElements(V, Packed), V); 465 } 466 static Constant *getAnon(LLVMContext &Ctx, ArrayRef<Constant *> V, 467 bool Packed = false) { 468 return get(getTypeForElements(Ctx, V, Packed), V); 469 } 470 471 /// Return an anonymous struct type to use for a constant with the specified 472 /// set of elements. The list must not be empty. 473 static StructType *getTypeForElements(ArrayRef<Constant *> V, 474 bool Packed = false); 475 /// This version of the method allows an empty list. 476 static StructType *getTypeForElements(LLVMContext &Ctx, 477 ArrayRef<Constant *> V, 478 bool Packed = false); 479 480 /// Specialization - reduce amount of casting. 481 inline StructType *getType() const { 482 return cast<StructType>(Value::getType()); 483 } 484 485 /// Methods for support type inquiry through isa, cast, and dyn_cast: 486 static bool classof(const Value *V) { 487 return V->getValueID() == ConstantStructVal; 488 } 489 }; 490 491 //===----------------------------------------------------------------------===// 492 /// Constant Vector Declarations 493 /// 494 class ConstantVector final : public ConstantAggregate { 495 friend struct ConstantAggrKeyType<ConstantVector>; 496 friend class Constant; 497 498 ConstantVector(VectorType *T, ArrayRef<Constant *> Val); 499 500 void destroyConstantImpl(); 501 Value *handleOperandChangeImpl(Value *From, Value *To); 502 503 public: 504 // ConstantVector accessors 505 static Constant *get(ArrayRef<Constant *> V); 506 507 private: 508 static Constant *getImpl(ArrayRef<Constant *> V); 509 510 public: 511 /// Return a ConstantVector with the specified constant in each element. 512 /// Note that this might not return an instance of ConstantVector 513 static Constant *getSplat(ElementCount EC, Constant *Elt); 514 515 /// Specialize the getType() method to always return a FixedVectorType, 516 /// which reduces the amount of casting needed in parts of the compiler. 517 inline FixedVectorType *getType() const { 518 return cast<FixedVectorType>(Value::getType()); 519 } 520 521 /// If all elements of the vector constant have the same value, return that 522 /// value. Otherwise, return nullptr. Ignore undefined elements by setting 523 /// AllowUndefs to true. 524 Constant *getSplatValue(bool AllowUndefs = false) const; 525 526 /// Methods for support type inquiry through isa, cast, and dyn_cast: 527 static bool classof(const Value *V) { 528 return V->getValueID() == ConstantVectorVal; 529 } 530 }; 531 532 //===----------------------------------------------------------------------===// 533 /// A constant pointer value that points to null 534 /// 535 class ConstantPointerNull final : public ConstantData { 536 friend class Constant; 537 538 explicit ConstantPointerNull(PointerType *T) 539 : ConstantData(T, Value::ConstantPointerNullVal) {} 540 541 void destroyConstantImpl(); 542 543 public: 544 ConstantPointerNull(const ConstantPointerNull &) = delete; 545 546 /// Static factory methods - Return objects of the specified value 547 static ConstantPointerNull *get(PointerType *T); 548 549 /// Specialize the getType() method to always return an PointerType, 550 /// which reduces the amount of casting needed in parts of the compiler. 551 inline PointerType *getType() const { 552 return cast<PointerType>(Value::getType()); 553 } 554 555 /// Methods for support type inquiry through isa, cast, and dyn_cast: 556 static bool classof(const Value *V) { 557 return V->getValueID() == ConstantPointerNullVal; 558 } 559 }; 560 561 //===----------------------------------------------------------------------===// 562 /// ConstantDataSequential - A vector or array constant whose element type is a 563 /// simple 1/2/4/8-byte integer or half/bfloat/float/double, and whose elements 564 /// are just simple data values (i.e. ConstantInt/ConstantFP). This Constant 565 /// node has no operands because it stores all of the elements of the constant 566 /// as densely packed data, instead of as Value*'s. 567 /// 568 /// This is the common base class of ConstantDataArray and ConstantDataVector. 569 /// 570 class ConstantDataSequential : public ConstantData { 571 friend class LLVMContextImpl; 572 friend class Constant; 573 574 /// A pointer to the bytes underlying this constant (which is owned by the 575 /// uniquing StringMap). 576 const char *DataElements; 577 578 /// This forms a link list of ConstantDataSequential nodes that have 579 /// the same value but different type. For example, 0,0,0,1 could be a 4 580 /// element array of i8, or a 1-element array of i32. They'll both end up in 581 /// the same StringMap bucket, linked up. 582 std::unique_ptr<ConstantDataSequential> Next; 583 584 void destroyConstantImpl(); 585 586 protected: 587 explicit ConstantDataSequential(Type *ty, ValueTy VT, const char *Data) 588 : ConstantData(ty, VT), DataElements(Data) {} 589 590 static Constant *getImpl(StringRef Bytes, Type *Ty); 591 592 public: 593 ConstantDataSequential(const ConstantDataSequential &) = delete; 594 595 /// Return true if a ConstantDataSequential can be formed with a vector or 596 /// array of the specified element type. 597 /// ConstantDataArray only works with normal float and int types that are 598 /// stored densely in memory, not with things like i42 or x86_f80. 599 static bool isElementTypeCompatible(Type *Ty); 600 601 /// If this is a sequential container of integers (of any size), return the 602 /// specified element in the low bits of a uint64_t. 603 uint64_t getElementAsInteger(unsigned i) const; 604 605 /// If this is a sequential container of integers (of any size), return the 606 /// specified element as an APInt. 607 APInt getElementAsAPInt(unsigned i) const; 608 609 /// If this is a sequential container of floating point type, return the 610 /// specified element as an APFloat. 611 APFloat getElementAsAPFloat(unsigned i) const; 612 613 /// If this is an sequential container of floats, return the specified element 614 /// as a float. 615 float getElementAsFloat(unsigned i) const; 616 617 /// If this is an sequential container of doubles, return the specified 618 /// element as a double. 619 double getElementAsDouble(unsigned i) const; 620 621 /// Return a Constant for a specified index's element. 622 /// Note that this has to compute a new constant to return, so it isn't as 623 /// efficient as getElementAsInteger/Float/Double. 624 Constant *getElementAsConstant(unsigned i) const; 625 626 /// Return the element type of the array/vector. 627 Type *getElementType() const; 628 629 /// Return the number of elements in the array or vector. 630 unsigned getNumElements() const; 631 632 /// Return the size (in bytes) of each element in the array/vector. 633 /// The size of the elements is known to be a multiple of one byte. 634 uint64_t getElementByteSize() const; 635 636 /// This method returns true if this is an array of \p CharSize integers. 637 bool isString(unsigned CharSize = 8) const; 638 639 /// This method returns true if the array "isString", ends with a null byte, 640 /// and does not contains any other null bytes. 641 bool isCString() const; 642 643 /// If this array is isString(), then this method returns the array as a 644 /// StringRef. Otherwise, it asserts out. 645 StringRef getAsString() const { 646 assert(isString() && "Not a string"); 647 return getRawDataValues(); 648 } 649 650 /// If this array is isCString(), then this method returns the array (without 651 /// the trailing null byte) as a StringRef. Otherwise, it asserts out. 652 StringRef getAsCString() const { 653 assert(isCString() && "Isn't a C string"); 654 StringRef Str = getAsString(); 655 return Str.substr(0, Str.size() - 1); 656 } 657 658 /// Return the raw, underlying, bytes of this data. Note that this is an 659 /// extremely tricky thing to work with, as it exposes the host endianness of 660 /// the data elements. 661 StringRef getRawDataValues() const; 662 663 /// Methods for support type inquiry through isa, cast, and dyn_cast: 664 static bool classof(const Value *V) { 665 return V->getValueID() == ConstantDataArrayVal || 666 V->getValueID() == ConstantDataVectorVal; 667 } 668 669 private: 670 const char *getElementPointer(unsigned Elt) const; 671 }; 672 673 //===----------------------------------------------------------------------===// 674 /// An array constant whose element type is a simple 1/2/4/8-byte integer or 675 /// float/double, and whose elements are just simple data values 676 /// (i.e. ConstantInt/ConstantFP). This Constant node has no operands because it 677 /// stores all of the elements of the constant as densely packed data, instead 678 /// of as Value*'s. 679 class ConstantDataArray final : public ConstantDataSequential { 680 friend class ConstantDataSequential; 681 682 explicit ConstantDataArray(Type *ty, const char *Data) 683 : ConstantDataSequential(ty, ConstantDataArrayVal, Data) {} 684 685 public: 686 ConstantDataArray(const ConstantDataArray &) = delete; 687 688 /// get() constructor - Return a constant with array type with an element 689 /// count and element type matching the ArrayRef passed in. Note that this 690 /// can return a ConstantAggregateZero object. 691 template <typename ElementTy> 692 static Constant *get(LLVMContext &Context, ArrayRef<ElementTy> Elts) { 693 const char *Data = reinterpret_cast<const char *>(Elts.data()); 694 return getRaw(StringRef(Data, Elts.size() * sizeof(ElementTy)), Elts.size(), 695 Type::getScalarTy<ElementTy>(Context)); 696 } 697 698 /// get() constructor - ArrayTy needs to be compatible with 699 /// ArrayRef<ElementTy>. Calls get(LLVMContext, ArrayRef<ElementTy>). 700 template <typename ArrayTy> 701 static Constant *get(LLVMContext &Context, ArrayTy &Elts) { 702 return ConstantDataArray::get(Context, makeArrayRef(Elts)); 703 } 704 705 /// getRaw() constructor - Return a constant with array type with an element 706 /// count and element type matching the NumElements and ElementTy parameters 707 /// passed in. Note that this can return a ConstantAggregateZero object. 708 /// ElementTy must be one of i8/i16/i32/i64/half/bfloat/float/double. Data is 709 /// the buffer containing the elements. Be careful to make sure Data uses the 710 /// right endianness, the buffer will be used as-is. 711 static Constant *getRaw(StringRef Data, uint64_t NumElements, 712 Type *ElementTy) { 713 Type *Ty = ArrayType::get(ElementTy, NumElements); 714 return getImpl(Data, Ty); 715 } 716 717 /// getFP() constructors - Return a constant of array type with a float 718 /// element type taken from argument `ElementType', and count taken from 719 /// argument `Elts'. The amount of bits of the contained type must match the 720 /// number of bits of the type contained in the passed in ArrayRef. 721 /// (i.e. half or bfloat for 16bits, float for 32bits, double for 64bits) Note 722 /// that this can return a ConstantAggregateZero object. 723 static Constant *getFP(Type *ElementType, ArrayRef<uint16_t> Elts); 724 static Constant *getFP(Type *ElementType, ArrayRef<uint32_t> Elts); 725 static Constant *getFP(Type *ElementType, ArrayRef<uint64_t> Elts); 726 727 /// This method constructs a CDS and initializes it with a text string. 728 /// The default behavior (AddNull==true) causes a null terminator to 729 /// be placed at the end of the array (increasing the length of the string by 730 /// one more than the StringRef would normally indicate. Pass AddNull=false 731 /// to disable this behavior. 732 static Constant *getString(LLVMContext &Context, StringRef Initializer, 733 bool AddNull = true); 734 735 /// Specialize the getType() method to always return an ArrayType, 736 /// which reduces the amount of casting needed in parts of the compiler. 737 inline ArrayType *getType() const { 738 return cast<ArrayType>(Value::getType()); 739 } 740 741 /// Methods for support type inquiry through isa, cast, and dyn_cast: 742 static bool classof(const Value *V) { 743 return V->getValueID() == ConstantDataArrayVal; 744 } 745 }; 746 747 //===----------------------------------------------------------------------===// 748 /// A vector constant whose element type is a simple 1/2/4/8-byte integer or 749 /// float/double, and whose elements are just simple data values 750 /// (i.e. ConstantInt/ConstantFP). This Constant node has no operands because it 751 /// stores all of the elements of the constant as densely packed data, instead 752 /// of as Value*'s. 753 class ConstantDataVector final : public ConstantDataSequential { 754 friend class ConstantDataSequential; 755 756 explicit ConstantDataVector(Type *ty, const char *Data) 757 : ConstantDataSequential(ty, ConstantDataVectorVal, Data), 758 IsSplatSet(false) {} 759 // Cache whether or not the constant is a splat. 760 mutable bool IsSplatSet : 1; 761 mutable bool IsSplat : 1; 762 bool isSplatData() const; 763 764 public: 765 ConstantDataVector(const ConstantDataVector &) = delete; 766 767 /// get() constructors - Return a constant with vector type with an element 768 /// count and element type matching the ArrayRef passed in. Note that this 769 /// can return a ConstantAggregateZero object. 770 static Constant *get(LLVMContext &Context, ArrayRef<uint8_t> Elts); 771 static Constant *get(LLVMContext &Context, ArrayRef<uint16_t> Elts); 772 static Constant *get(LLVMContext &Context, ArrayRef<uint32_t> Elts); 773 static Constant *get(LLVMContext &Context, ArrayRef<uint64_t> Elts); 774 static Constant *get(LLVMContext &Context, ArrayRef<float> Elts); 775 static Constant *get(LLVMContext &Context, ArrayRef<double> Elts); 776 777 /// getRaw() constructor - Return a constant with vector type with an element 778 /// count and element type matching the NumElements and ElementTy parameters 779 /// passed in. Note that this can return a ConstantAggregateZero object. 780 /// ElementTy must be one of i8/i16/i32/i64/half/bfloat/float/double. Data is 781 /// the buffer containing the elements. Be careful to make sure Data uses the 782 /// right endianness, the buffer will be used as-is. 783 static Constant *getRaw(StringRef Data, uint64_t NumElements, 784 Type *ElementTy) { 785 Type *Ty = VectorType::get(ElementTy, ElementCount::getFixed(NumElements)); 786 return getImpl(Data, Ty); 787 } 788 789 /// getFP() constructors - Return a constant of vector type with a float 790 /// element type taken from argument `ElementType', and count taken from 791 /// argument `Elts'. The amount of bits of the contained type must match the 792 /// number of bits of the type contained in the passed in ArrayRef. 793 /// (i.e. half or bfloat for 16bits, float for 32bits, double for 64bits) Note 794 /// that this can return a ConstantAggregateZero object. 795 static Constant *getFP(Type *ElementType, ArrayRef<uint16_t> Elts); 796 static Constant *getFP(Type *ElementType, ArrayRef<uint32_t> Elts); 797 static Constant *getFP(Type *ElementType, ArrayRef<uint64_t> Elts); 798 799 /// Return a ConstantVector with the specified constant in each element. 800 /// The specified constant has to be a of a compatible type (i8/i16/ 801 /// i32/i64/half/bfloat/float/double) and must be a ConstantFP or ConstantInt. 802 static Constant *getSplat(unsigned NumElts, Constant *Elt); 803 804 /// Returns true if this is a splat constant, meaning that all elements have 805 /// the same value. 806 bool isSplat() const; 807 808 /// If this is a splat constant, meaning that all of the elements have the 809 /// same value, return that value. Otherwise return NULL. 810 Constant *getSplatValue() const; 811 812 /// Specialize the getType() method to always return a FixedVectorType, 813 /// which reduces the amount of casting needed in parts of the compiler. 814 inline FixedVectorType *getType() const { 815 return cast<FixedVectorType>(Value::getType()); 816 } 817 818 /// Methods for support type inquiry through isa, cast, and dyn_cast: 819 static bool classof(const Value *V) { 820 return V->getValueID() == ConstantDataVectorVal; 821 } 822 }; 823 824 //===----------------------------------------------------------------------===// 825 /// A constant token which is empty 826 /// 827 class ConstantTokenNone final : public ConstantData { 828 friend class Constant; 829 830 explicit ConstantTokenNone(LLVMContext &Context) 831 : ConstantData(Type::getTokenTy(Context), ConstantTokenNoneVal) {} 832 833 void destroyConstantImpl(); 834 835 public: 836 ConstantTokenNone(const ConstantTokenNone &) = delete; 837 838 /// Return the ConstantTokenNone. 839 static ConstantTokenNone *get(LLVMContext &Context); 840 841 /// Methods to support type inquiry through isa, cast, and dyn_cast. 842 static bool classof(const Value *V) { 843 return V->getValueID() == ConstantTokenNoneVal; 844 } 845 }; 846 847 /// The address of a basic block. 848 /// 849 class BlockAddress final : public Constant { 850 friend class Constant; 851 852 BlockAddress(Function *F, BasicBlock *BB); 853 854 void *operator new(size_t S) { return User::operator new(S, 2); } 855 856 void destroyConstantImpl(); 857 Value *handleOperandChangeImpl(Value *From, Value *To); 858 859 public: 860 void operator delete(void *Ptr) { User::operator delete(Ptr); } 861 862 /// Return a BlockAddress for the specified function and basic block. 863 static BlockAddress *get(Function *F, BasicBlock *BB); 864 865 /// Return a BlockAddress for the specified basic block. The basic 866 /// block must be embedded into a function. 867 static BlockAddress *get(BasicBlock *BB); 868 869 /// Lookup an existing \c BlockAddress constant for the given BasicBlock. 870 /// 871 /// \returns 0 if \c !BB->hasAddressTaken(), otherwise the \c BlockAddress. 872 static BlockAddress *lookup(const BasicBlock *BB); 873 874 /// Transparently provide more efficient getOperand methods. 875 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value); 876 877 Function *getFunction() const { return (Function *)Op<0>().get(); } 878 BasicBlock *getBasicBlock() const { return (BasicBlock *)Op<1>().get(); } 879 880 /// Methods for support type inquiry through isa, cast, and dyn_cast: 881 static bool classof(const Value *V) { 882 return V->getValueID() == BlockAddressVal; 883 } 884 }; 885 886 template <> 887 struct OperandTraits<BlockAddress> 888 : public FixedNumOperandTraits<BlockAddress, 2> {}; 889 890 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(BlockAddress, Value) 891 892 /// Wrapper for a function that represents a value that 893 /// functionally represents the original function. This can be a function, 894 /// global alias to a function, or an ifunc. 895 class DSOLocalEquivalent final : public Constant { 896 friend class Constant; 897 898 DSOLocalEquivalent(GlobalValue *GV); 899 900 void *operator new(size_t S) { return User::operator new(S, 1); } 901 902 void destroyConstantImpl(); 903 Value *handleOperandChangeImpl(Value *From, Value *To); 904 905 public: 906 void operator delete(void *Ptr) { User::operator delete(Ptr); } 907 908 /// Return a DSOLocalEquivalent for the specified global value. 909 static DSOLocalEquivalent *get(GlobalValue *GV); 910 911 /// Transparently provide more efficient getOperand methods. 912 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value); 913 914 GlobalValue *getGlobalValue() const { 915 return cast<GlobalValue>(Op<0>().get()); 916 } 917 918 /// Methods for support type inquiry through isa, cast, and dyn_cast: 919 static bool classof(const Value *V) { 920 return V->getValueID() == DSOLocalEquivalentVal; 921 } 922 }; 923 924 template <> 925 struct OperandTraits<DSOLocalEquivalent> 926 : public FixedNumOperandTraits<DSOLocalEquivalent, 1> {}; 927 928 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(DSOLocalEquivalent, Value) 929 930 /// Wrapper for a value that won't be replaced with a CFI jump table 931 /// pointer in LowerTypeTestsModule. 932 class NoCFIValue final : public Constant { 933 friend class Constant; 934 935 NoCFIValue(GlobalValue *GV); 936 937 void *operator new(size_t S) { return User::operator new(S, 1); } 938 939 void destroyConstantImpl(); 940 Value *handleOperandChangeImpl(Value *From, Value *To); 941 942 public: 943 /// Return a NoCFIValue for the specified function. 944 static NoCFIValue *get(GlobalValue *GV); 945 946 /// Transparently provide more efficient getOperand methods. 947 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value); 948 949 GlobalValue *getGlobalValue() const { 950 return cast<GlobalValue>(Op<0>().get()); 951 } 952 953 /// Methods for support type inquiry through isa, cast, and dyn_cast: 954 static bool classof(const Value *V) { 955 return V->getValueID() == NoCFIValueVal; 956 } 957 }; 958 959 template <> 960 struct OperandTraits<NoCFIValue> : public FixedNumOperandTraits<NoCFIValue, 1> { 961 }; 962 963 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(NoCFIValue, Value) 964 965 //===----------------------------------------------------------------------===// 966 /// A constant value that is initialized with an expression using 967 /// other constant values. 968 /// 969 /// This class uses the standard Instruction opcodes to define the various 970 /// constant expressions. The Opcode field for the ConstantExpr class is 971 /// maintained in the Value::SubclassData field. 972 class ConstantExpr : public Constant { 973 friend struct ConstantExprKeyType; 974 friend class Constant; 975 976 void destroyConstantImpl(); 977 Value *handleOperandChangeImpl(Value *From, Value *To); 978 979 protected: 980 ConstantExpr(Type *ty, unsigned Opcode, Use *Ops, unsigned NumOps) 981 : Constant(ty, ConstantExprVal, Ops, NumOps) { 982 // Operation type (an Instruction opcode) is stored as the SubclassData. 983 setValueSubclassData(Opcode); 984 } 985 986 ~ConstantExpr() = default; 987 988 public: 989 // Static methods to construct a ConstantExpr of different kinds. Note that 990 // these methods may return a object that is not an instance of the 991 // ConstantExpr class, because they will attempt to fold the constant 992 // expression into something simpler if possible. 993 994 /// getAlignOf constant expr - computes the alignment of a type in a target 995 /// independent way (Note: the return type is an i64). 996 static Constant *getAlignOf(Type *Ty); 997 998 /// getSizeOf constant expr - computes the (alloc) size of a type (in 999 /// address-units, not bits) in a target independent way (Note: the return 1000 /// type is an i64). 1001 /// 1002 static Constant *getSizeOf(Type *Ty); 1003 1004 /// getOffsetOf constant expr - computes the offset of a struct field in a 1005 /// target independent way (Note: the return type is an i64). 1006 /// 1007 static Constant *getOffsetOf(StructType *STy, unsigned FieldNo); 1008 1009 /// getOffsetOf constant expr - This is a generalized form of getOffsetOf, 1010 /// which supports any aggregate type, and any Constant index. 1011 /// 1012 static Constant *getOffsetOf(Type *Ty, Constant *FieldNo); 1013 1014 static Constant *getNeg(Constant *C, bool HasNUW = false, 1015 bool HasNSW = false); 1016 static Constant *getFNeg(Constant *C); 1017 static Constant *getNot(Constant *C); 1018 static Constant *getAdd(Constant *C1, Constant *C2, bool HasNUW = false, 1019 bool HasNSW = false); 1020 static Constant *getSub(Constant *C1, Constant *C2, bool HasNUW = false, 1021 bool HasNSW = false); 1022 static Constant *getMul(Constant *C1, Constant *C2, bool HasNUW = false, 1023 bool HasNSW = false); 1024 static Constant *getAnd(Constant *C1, Constant *C2); 1025 static Constant *getOr(Constant *C1, Constant *C2); 1026 static Constant *getXor(Constant *C1, Constant *C2); 1027 static Constant *getUMin(Constant *C1, Constant *C2); 1028 static Constant *getShl(Constant *C1, Constant *C2, bool HasNUW = false, 1029 bool HasNSW = false); 1030 static Constant *getLShr(Constant *C1, Constant *C2, bool isExact = false); 1031 static Constant *getAShr(Constant *C1, Constant *C2, bool isExact = false); 1032 static Constant *getTrunc(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1033 static Constant *getSExt(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1034 static Constant *getZExt(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1035 static Constant *getFPTrunc(Constant *C, Type *Ty, 1036 bool OnlyIfReduced = false); 1037 static Constant *getFPExtend(Constant *C, Type *Ty, 1038 bool OnlyIfReduced = false); 1039 static Constant *getUIToFP(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1040 static Constant *getSIToFP(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1041 static Constant *getFPToUI(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1042 static Constant *getFPToSI(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1043 static Constant *getPtrToInt(Constant *C, Type *Ty, 1044 bool OnlyIfReduced = false); 1045 static Constant *getIntToPtr(Constant *C, Type *Ty, 1046 bool OnlyIfReduced = false); 1047 static Constant *getBitCast(Constant *C, Type *Ty, 1048 bool OnlyIfReduced = false); 1049 static Constant *getAddrSpaceCast(Constant *C, Type *Ty, 1050 bool OnlyIfReduced = false); 1051 1052 static Constant *getNSWNeg(Constant *C) { return getNeg(C, false, true); } 1053 static Constant *getNUWNeg(Constant *C) { return getNeg(C, true, false); } 1054 1055 static Constant *getNSWAdd(Constant *C1, Constant *C2) { 1056 return getAdd(C1, C2, false, true); 1057 } 1058 1059 static Constant *getNUWAdd(Constant *C1, Constant *C2) { 1060 return getAdd(C1, C2, true, false); 1061 } 1062 1063 static Constant *getNSWSub(Constant *C1, Constant *C2) { 1064 return getSub(C1, C2, false, true); 1065 } 1066 1067 static Constant *getNUWSub(Constant *C1, Constant *C2) { 1068 return getSub(C1, C2, true, false); 1069 } 1070 1071 static Constant *getNSWMul(Constant *C1, Constant *C2) { 1072 return getMul(C1, C2, false, true); 1073 } 1074 1075 static Constant *getNUWMul(Constant *C1, Constant *C2) { 1076 return getMul(C1, C2, true, false); 1077 } 1078 1079 static Constant *getNSWShl(Constant *C1, Constant *C2) { 1080 return getShl(C1, C2, false, true); 1081 } 1082 1083 static Constant *getNUWShl(Constant *C1, Constant *C2) { 1084 return getShl(C1, C2, true, false); 1085 } 1086 1087 static Constant *getExactAShr(Constant *C1, Constant *C2) { 1088 return getAShr(C1, C2, true); 1089 } 1090 1091 static Constant *getExactLShr(Constant *C1, Constant *C2) { 1092 return getLShr(C1, C2, true); 1093 } 1094 1095 /// If C is a scalar/fixed width vector of known powers of 2, then this 1096 /// function returns a new scalar/fixed width vector obtained from logBase2 1097 /// of C. Undef vector elements are set to zero. 1098 /// Return a null pointer otherwise. 1099 static Constant *getExactLogBase2(Constant *C); 1100 1101 /// Return the identity constant for a binary opcode. 1102 /// The identity constant C is defined as X op C = X and C op X = X for every 1103 /// X when the binary operation is commutative. If the binop is not 1104 /// commutative, callers can acquire the operand 1 identity constant by 1105 /// setting AllowRHSConstant to true. For example, any shift has a zero 1106 /// identity constant for operand 1: X shift 0 = X. 1107 /// If this is a fadd/fsub operation and we don't care about signed zeros, 1108 /// then setting NSZ to true returns the identity +0.0 instead of -0.0. 1109 /// Return nullptr if the operator does not have an identity constant. 1110 static Constant *getBinOpIdentity(unsigned Opcode, Type *Ty, 1111 bool AllowRHSConstant = false, 1112 bool NSZ = false); 1113 1114 /// Return the absorbing element for the given binary 1115 /// operation, i.e. a constant C such that X op C = C and C op X = C for 1116 /// every X. For example, this returns zero for integer multiplication. 1117 /// It returns null if the operator doesn't have an absorbing element. 1118 static Constant *getBinOpAbsorber(unsigned Opcode, Type *Ty); 1119 1120 /// Transparently provide more efficient getOperand methods. 1121 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant); 1122 1123 /// Convenience function for getting a Cast operation. 1124 /// 1125 /// \param ops The opcode for the conversion 1126 /// \param C The constant to be converted 1127 /// \param Ty The type to which the constant is converted 1128 /// \param OnlyIfReduced see \a getWithOperands() docs. 1129 static Constant *getCast(unsigned ops, Constant *C, Type *Ty, 1130 bool OnlyIfReduced = false); 1131 1132 // Create a ZExt or BitCast cast constant expression 1133 static Constant * 1134 getZExtOrBitCast(Constant *C, ///< The constant to zext or bitcast 1135 Type *Ty ///< The type to zext or bitcast C to 1136 ); 1137 1138 // Create a SExt or BitCast cast constant expression 1139 static Constant * 1140 getSExtOrBitCast(Constant *C, ///< The constant to sext or bitcast 1141 Type *Ty ///< The type to sext or bitcast C to 1142 ); 1143 1144 // Create a Trunc or BitCast cast constant expression 1145 static Constant * 1146 getTruncOrBitCast(Constant *C, ///< The constant to trunc or bitcast 1147 Type *Ty ///< The type to trunc or bitcast C to 1148 ); 1149 1150 /// Create either an sext, trunc or nothing, depending on whether Ty is 1151 /// wider, narrower or the same as C->getType(). This only works with 1152 /// integer or vector of integer types. 1153 static Constant *getSExtOrTrunc(Constant *C, Type *Ty); 1154 1155 /// Create a BitCast, AddrSpaceCast, or a PtrToInt cast constant 1156 /// expression. 1157 static Constant * 1158 getPointerCast(Constant *C, ///< The pointer value to be casted (operand 0) 1159 Type *Ty ///< The type to which cast should be made 1160 ); 1161 1162 /// Create a BitCast or AddrSpaceCast for a pointer type depending on 1163 /// the address space. 1164 static Constant *getPointerBitCastOrAddrSpaceCast( 1165 Constant *C, ///< The constant to addrspacecast or bitcast 1166 Type *Ty ///< The type to bitcast or addrspacecast C to 1167 ); 1168 1169 /// Create a ZExt, Bitcast or Trunc for integer -> integer casts 1170 static Constant * 1171 getIntegerCast(Constant *C, ///< The integer constant to be casted 1172 Type *Ty, ///< The integer type to cast to 1173 bool IsSigned ///< Whether C should be treated as signed or not 1174 ); 1175 1176 /// Create a FPExt, Bitcast or FPTrunc for fp -> fp casts 1177 static Constant *getFPCast(Constant *C, ///< The integer constant to be casted 1178 Type *Ty ///< The integer type to cast to 1179 ); 1180 1181 /// Return true if this is a convert constant expression 1182 bool isCast() const; 1183 1184 /// Return true if this is a compare constant expression 1185 bool isCompare() const; 1186 1187 /// Select constant expr 1188 /// 1189 /// \param OnlyIfReducedTy see \a getWithOperands() docs. 1190 static Constant *getSelect(Constant *C, Constant *V1, Constant *V2, 1191 Type *OnlyIfReducedTy = nullptr); 1192 1193 /// get - Return a unary operator constant expression, 1194 /// folding if possible. 1195 /// 1196 /// \param OnlyIfReducedTy see \a getWithOperands() docs. 1197 static Constant *get(unsigned Opcode, Constant *C1, unsigned Flags = 0, 1198 Type *OnlyIfReducedTy = nullptr); 1199 1200 /// get - Return a binary or shift operator constant expression, 1201 /// folding if possible. 1202 /// 1203 /// \param OnlyIfReducedTy see \a getWithOperands() docs. 1204 static Constant *get(unsigned Opcode, Constant *C1, Constant *C2, 1205 unsigned Flags = 0, Type *OnlyIfReducedTy = nullptr); 1206 1207 /// Return an ICmp or FCmp comparison operator constant expression. 1208 /// 1209 /// \param OnlyIfReduced see \a getWithOperands() docs. 1210 static Constant *getCompare(unsigned short pred, Constant *C1, Constant *C2, 1211 bool OnlyIfReduced = false); 1212 1213 /// get* - Return some common constants without having to 1214 /// specify the full Instruction::OPCODE identifier. 1215 /// 1216 static Constant *getICmp(unsigned short pred, Constant *LHS, Constant *RHS, 1217 bool OnlyIfReduced = false); 1218 static Constant *getFCmp(unsigned short pred, Constant *LHS, Constant *RHS, 1219 bool OnlyIfReduced = false); 1220 1221 /// Getelementptr form. Value* is only accepted for convenience; 1222 /// all elements must be Constants. 1223 /// 1224 /// \param InRangeIndex the inrange index if present or None. 1225 /// \param OnlyIfReducedTy see \a getWithOperands() docs. 1226 static Constant *getGetElementPtr(Type *Ty, Constant *C, 1227 ArrayRef<Constant *> IdxList, 1228 bool InBounds = false, 1229 Optional<unsigned> InRangeIndex = None, 1230 Type *OnlyIfReducedTy = nullptr) { 1231 return getGetElementPtr( 1232 Ty, C, makeArrayRef((Value *const *)IdxList.data(), IdxList.size()), 1233 InBounds, InRangeIndex, OnlyIfReducedTy); 1234 } 1235 static Constant *getGetElementPtr(Type *Ty, Constant *C, Constant *Idx, 1236 bool InBounds = false, 1237 Optional<unsigned> InRangeIndex = None, 1238 Type *OnlyIfReducedTy = nullptr) { 1239 // This form of the function only exists to avoid ambiguous overload 1240 // warnings about whether to convert Idx to ArrayRef<Constant *> or 1241 // ArrayRef<Value *>. 1242 return getGetElementPtr(Ty, C, cast<Value>(Idx), InBounds, InRangeIndex, 1243 OnlyIfReducedTy); 1244 } 1245 static Constant *getGetElementPtr(Type *Ty, Constant *C, 1246 ArrayRef<Value *> IdxList, 1247 bool InBounds = false, 1248 Optional<unsigned> InRangeIndex = None, 1249 Type *OnlyIfReducedTy = nullptr); 1250 1251 /// Create an "inbounds" getelementptr. See the documentation for the 1252 /// "inbounds" flag in LangRef.html for details. 1253 static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C, 1254 ArrayRef<Constant *> IdxList) { 1255 return getGetElementPtr(Ty, C, IdxList, true); 1256 } 1257 static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C, 1258 Constant *Idx) { 1259 // This form of the function only exists to avoid ambiguous overload 1260 // warnings about whether to convert Idx to ArrayRef<Constant *> or 1261 // ArrayRef<Value *>. 1262 return getGetElementPtr(Ty, C, Idx, true); 1263 } 1264 static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C, 1265 ArrayRef<Value *> IdxList) { 1266 return getGetElementPtr(Ty, C, IdxList, true); 1267 } 1268 1269 static Constant *getExtractElement(Constant *Vec, Constant *Idx, 1270 Type *OnlyIfReducedTy = nullptr); 1271 static Constant *getInsertElement(Constant *Vec, Constant *Elt, Constant *Idx, 1272 Type *OnlyIfReducedTy = nullptr); 1273 static Constant *getShuffleVector(Constant *V1, Constant *V2, 1274 ArrayRef<int> Mask, 1275 Type *OnlyIfReducedTy = nullptr); 1276 1277 /// Return the opcode at the root of this constant expression 1278 unsigned getOpcode() const { return getSubclassDataFromValue(); } 1279 1280 /// Return the ICMP or FCMP predicate value. Assert if this is not an ICMP or 1281 /// FCMP constant expression. 1282 unsigned getPredicate() const; 1283 1284 /// Assert that this is a shufflevector and return the mask. See class 1285 /// ShuffleVectorInst for a description of the mask representation. 1286 ArrayRef<int> getShuffleMask() const; 1287 1288 /// Assert that this is a shufflevector and return the mask. 1289 /// 1290 /// TODO: This is a temporary hack until we update the bitcode format for 1291 /// shufflevector. 1292 Constant *getShuffleMaskForBitcode() const; 1293 1294 /// Return a string representation for an opcode. 1295 const char *getOpcodeName() const; 1296 1297 /// This returns the current constant expression with the operands replaced 1298 /// with the specified values. The specified array must have the same number 1299 /// of operands as our current one. 1300 Constant *getWithOperands(ArrayRef<Constant *> Ops) const { 1301 return getWithOperands(Ops, getType()); 1302 } 1303 1304 /// Get the current expression with the operands replaced. 1305 /// 1306 /// Return the current constant expression with the operands replaced with \c 1307 /// Ops and the type with \c Ty. The new operands must have the same number 1308 /// as the current ones. 1309 /// 1310 /// If \c OnlyIfReduced is \c true, nullptr will be returned unless something 1311 /// gets constant-folded, the type changes, or the expression is otherwise 1312 /// canonicalized. This parameter should almost always be \c false. 1313 Constant *getWithOperands(ArrayRef<Constant *> Ops, Type *Ty, 1314 bool OnlyIfReduced = false, 1315 Type *SrcTy = nullptr) const; 1316 1317 /// Returns an Instruction which implements the same operation as this 1318 /// ConstantExpr. If \p InsertBefore is not null, the new instruction is 1319 /// inserted before it, otherwise it is not inserted into any basic block. 1320 /// 1321 /// A better approach to this could be to have a constructor for Instruction 1322 /// which would take a ConstantExpr parameter, but that would have spread 1323 /// implementation details of ConstantExpr outside of Constants.cpp, which 1324 /// would make it harder to remove ConstantExprs altogether. 1325 Instruction *getAsInstruction(Instruction *InsertBefore = nullptr) const; 1326 1327 /// Whether creating a constant expression for this binary operator is 1328 /// desirable. 1329 static bool isDesirableBinOp(unsigned Opcode); 1330 1331 /// Whether creating a constant expression for this binary operator is 1332 /// supported. 1333 static bool isSupportedBinOp(unsigned Opcode); 1334 1335 /// Methods for support type inquiry through isa, cast, and dyn_cast: 1336 static bool classof(const Value *V) { 1337 return V->getValueID() == ConstantExprVal; 1338 } 1339 1340 private: 1341 // Shadow Value::setValueSubclassData with a private forwarding method so that 1342 // subclasses cannot accidentally use it. 1343 void setValueSubclassData(unsigned short D) { 1344 Value::setValueSubclassData(D); 1345 } 1346 }; 1347 1348 template <> 1349 struct OperandTraits<ConstantExpr> 1350 : public VariadicOperandTraits<ConstantExpr, 1> {}; 1351 1352 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantExpr, Constant) 1353 1354 //===----------------------------------------------------------------------===// 1355 /// 'undef' values are things that do not have specified contents. 1356 /// These are used for a variety of purposes, including global variable 1357 /// initializers and operands to instructions. 'undef' values can occur with 1358 /// any first-class type. 1359 /// 1360 /// Undef values aren't exactly constants; if they have multiple uses, they 1361 /// can appear to have different bit patterns at each use. See 1362 /// LangRef.html#undefvalues for details. 1363 /// 1364 class UndefValue : public ConstantData { 1365 friend class Constant; 1366 1367 explicit UndefValue(Type *T) : ConstantData(T, UndefValueVal) {} 1368 1369 void destroyConstantImpl(); 1370 1371 protected: 1372 explicit UndefValue(Type *T, ValueTy vty) : ConstantData(T, vty) {} 1373 1374 public: 1375 UndefValue(const UndefValue &) = delete; 1376 1377 /// Static factory methods - Return an 'undef' object of the specified type. 1378 static UndefValue *get(Type *T); 1379 1380 /// If this Undef has array or vector type, return a undef with the right 1381 /// element type. 1382 UndefValue *getSequentialElement() const; 1383 1384 /// If this undef has struct type, return a undef with the right element type 1385 /// for the specified element. 1386 UndefValue *getStructElement(unsigned Elt) const; 1387 1388 /// Return an undef of the right value for the specified GEP index if we can, 1389 /// otherwise return null (e.g. if C is a ConstantExpr). 1390 UndefValue *getElementValue(Constant *C) const; 1391 1392 /// Return an undef of the right value for the specified GEP index. 1393 UndefValue *getElementValue(unsigned Idx) const; 1394 1395 /// Return the number of elements in the array, vector, or struct. 1396 unsigned getNumElements() const; 1397 1398 /// Methods for support type inquiry through isa, cast, and dyn_cast: 1399 static bool classof(const Value *V) { 1400 return V->getValueID() == UndefValueVal || 1401 V->getValueID() == PoisonValueVal; 1402 } 1403 }; 1404 1405 //===----------------------------------------------------------------------===// 1406 /// In order to facilitate speculative execution, many instructions do not 1407 /// invoke immediate undefined behavior when provided with illegal operands, 1408 /// and return a poison value instead. 1409 /// 1410 /// see LangRef.html#poisonvalues for details. 1411 /// 1412 class PoisonValue final : public UndefValue { 1413 friend class Constant; 1414 1415 explicit PoisonValue(Type *T) : UndefValue(T, PoisonValueVal) {} 1416 1417 void destroyConstantImpl(); 1418 1419 public: 1420 PoisonValue(const PoisonValue &) = delete; 1421 1422 /// Static factory methods - Return an 'poison' object of the specified type. 1423 static PoisonValue *get(Type *T); 1424 1425 /// If this poison has array or vector type, return a poison with the right 1426 /// element type. 1427 PoisonValue *getSequentialElement() const; 1428 1429 /// If this poison has struct type, return a poison with the right element 1430 /// type for the specified element. 1431 PoisonValue *getStructElement(unsigned Elt) const; 1432 1433 /// Return an poison of the right value for the specified GEP index if we can, 1434 /// otherwise return null (e.g. if C is a ConstantExpr). 1435 PoisonValue *getElementValue(Constant *C) const; 1436 1437 /// Return an poison of the right value for the specified GEP index. 1438 PoisonValue *getElementValue(unsigned Idx) const; 1439 1440 /// Methods for support type inquiry through isa, cast, and dyn_cast: 1441 static bool classof(const Value *V) { 1442 return V->getValueID() == PoisonValueVal; 1443 } 1444 }; 1445 1446 } // end namespace llvm 1447 1448 #endif // LLVM_IR_CONSTANTS_H 1449