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/STLExtras.h" 27 #include "llvm/ADT/StringRef.h" 28 #include "llvm/IR/Constant.h" 29 #include "llvm/IR/DerivedTypes.h" 30 #include "llvm/IR/OperandTraits.h" 31 #include "llvm/IR/User.h" 32 #include "llvm/IR/Value.h" 33 #include "llvm/Support/Casting.h" 34 #include "llvm/Support/Compiler.h" 35 #include "llvm/Support/ErrorHandling.h" 36 #include <cassert> 37 #include <cstddef> 38 #include <cstdint> 39 #include <optional> 40 41 namespace llvm { 42 43 template <class ConstantClass> struct ConstantAggrKeyType; 44 45 /// Base class for constants with no operands. 46 /// 47 /// These constants have no operands; they represent their data directly. 48 /// Since they can be in use by unrelated modules (and are never based on 49 /// GlobalValues), it never makes sense to RAUW them. 50 class ConstantData : public Constant { 51 friend class Constant; 52 53 Value *handleOperandChangeImpl(Value *From, Value *To) { 54 llvm_unreachable("Constant data does not have operands!"); 55 } 56 57 protected: 58 explicit ConstantData(Type *Ty, ValueTy VT) : Constant(Ty, VT, nullptr, 0) {} 59 60 void *operator new(size_t S) { return User::operator new(S, 0); } 61 62 public: 63 void operator delete(void *Ptr) { User::operator delete(Ptr); } 64 65 ConstantData(const ConstantData &) = delete; 66 67 /// Methods to support type inquiry through isa, cast, and dyn_cast. 68 static bool classof(const Value *V) { 69 return V->getValueID() >= ConstantDataFirstVal && 70 V->getValueID() <= ConstantDataLastVal; 71 } 72 }; 73 74 //===----------------------------------------------------------------------===// 75 /// This is the shared class of boolean and integer constants. This class 76 /// represents both boolean and integral constants. 77 /// Class for constant integers. 78 class ConstantInt final : public ConstantData { 79 friend class Constant; 80 81 APInt Val; 82 83 ConstantInt(IntegerType *Ty, const APInt &V); 84 85 void destroyConstantImpl(); 86 87 public: 88 ConstantInt(const ConstantInt &) = delete; 89 90 static ConstantInt *getTrue(LLVMContext &Context); 91 static ConstantInt *getFalse(LLVMContext &Context); 92 static ConstantInt *getBool(LLVMContext &Context, bool V); 93 static Constant *getTrue(Type *Ty); 94 static Constant *getFalse(Type *Ty); 95 static Constant *getBool(Type *Ty, bool V); 96 97 /// If Ty is a vector type, return a Constant with a splat of the given 98 /// value. Otherwise return a ConstantInt for the given value. 99 static Constant *get(Type *Ty, uint64_t V, bool IsSigned = false); 100 101 /// Return a ConstantInt with the specified integer value for the specified 102 /// type. If the type is wider than 64 bits, the value will be zero-extended 103 /// to fit the type, unless IsSigned is true, in which case the value will 104 /// be interpreted as a 64-bit signed integer and sign-extended to fit 105 /// the type. 106 /// Get a ConstantInt for a specific value. 107 static ConstantInt *get(IntegerType *Ty, uint64_t V, bool IsSigned = false); 108 109 /// Return a ConstantInt with the specified value for the specified type. The 110 /// value V will be canonicalized to a an unsigned APInt. Accessing it with 111 /// either getSExtValue() or getZExtValue() will yield a correctly sized and 112 /// signed value for the type Ty. 113 /// Get a ConstantInt for a specific signed value. 114 static ConstantInt *getSigned(IntegerType *Ty, int64_t V); 115 static Constant *getSigned(Type *Ty, int64_t V); 116 117 /// Return a ConstantInt with the specified value and an implied Type. The 118 /// type is the integer type that corresponds to the bit width of the value. 119 static ConstantInt *get(LLVMContext &Context, const APInt &V); 120 121 /// Return a ConstantInt constructed from the string strStart with the given 122 /// radix. 123 static ConstantInt *get(IntegerType *Ty, StringRef Str, uint8_t Radix); 124 125 /// If Ty is a vector type, return a Constant with a splat of the given 126 /// value. Otherwise return a ConstantInt for the given value. 127 static Constant *get(Type *Ty, const APInt &V); 128 129 /// Return the constant as an APInt value reference. This allows clients to 130 /// obtain a full-precision copy of the value. 131 /// Return the constant's value. 132 inline const APInt &getValue() const { return Val; } 133 134 /// getBitWidth - Return the bitwidth of this constant. 135 unsigned getBitWidth() const { return Val.getBitWidth(); } 136 137 /// Return the constant as a 64-bit unsigned integer value after it 138 /// has been zero extended as appropriate for the type of this constant. Note 139 /// that this method can assert if the value does not fit in 64 bits. 140 /// Return the zero extended value. 141 inline uint64_t getZExtValue() const { return Val.getZExtValue(); } 142 143 /// Return the constant as a 64-bit integer value after it has been sign 144 /// extended as appropriate for the type of this constant. Note that 145 /// this method can assert if the value does not fit in 64 bits. 146 /// Return the sign extended value. 147 inline int64_t getSExtValue() const { return Val.getSExtValue(); } 148 149 /// Return the constant as an llvm::MaybeAlign. 150 /// Note that this method can assert if the value does not fit in 64 bits or 151 /// is not a power of two. 152 inline MaybeAlign getMaybeAlignValue() const { 153 return MaybeAlign(getZExtValue()); 154 } 155 156 /// Return the constant as an llvm::Align, interpreting `0` as `Align(1)`. 157 /// Note that this method can assert if the value does not fit in 64 bits or 158 /// is not a power of two. 159 inline Align getAlignValue() const { 160 return getMaybeAlignValue().valueOrOne(); 161 } 162 163 /// A helper method that can be used to determine if the constant contained 164 /// within is equal to a constant. This only works for very small values, 165 /// because this is all that can be represented with all types. 166 /// Determine if this constant's value is same as an unsigned char. 167 bool equalsInt(uint64_t V) const { return Val == V; } 168 169 /// getType - Specialize the getType() method to always return an IntegerType, 170 /// which reduces the amount of casting needed in parts of the compiler. 171 /// 172 inline IntegerType *getType() const { 173 return cast<IntegerType>(Value::getType()); 174 } 175 176 /// This static method returns true if the type Ty is big enough to 177 /// represent the value V. This can be used to avoid having the get method 178 /// assert when V is larger than Ty can represent. Note that there are two 179 /// versions of this method, one for unsigned and one for signed integers. 180 /// Although ConstantInt canonicalizes everything to an unsigned integer, 181 /// the signed version avoids callers having to convert a signed quantity 182 /// to the appropriate unsigned type before calling the method. 183 /// @returns true if V is a valid value for type Ty 184 /// Determine if the value is in range for the given type. 185 static bool isValueValidForType(Type *Ty, uint64_t V); 186 static bool isValueValidForType(Type *Ty, int64_t V); 187 188 bool isNegative() const { return Val.isNegative(); } 189 190 /// This is just a convenience method to make client code smaller for a 191 /// common code. It also correctly performs the comparison without the 192 /// potential for an assertion from getZExtValue(). 193 bool isZero() const { return Val.isZero(); } 194 195 /// This is just a convenience method to make client code smaller for a 196 /// common case. It also correctly performs the comparison without the 197 /// potential for an assertion from getZExtValue(). 198 /// Determine if the value is one. 199 bool isOne() const { return Val.isOne(); } 200 201 /// This function will return true iff every bit in this constant is set 202 /// to true. 203 /// @returns true iff this constant's bits are all set to true. 204 /// Determine if the value is all ones. 205 bool isMinusOne() const { return Val.isAllOnes(); } 206 207 /// This function will return true iff this constant represents the largest 208 /// value that may be represented by the constant's type. 209 /// @returns true iff this is the largest value that may be represented 210 /// by this type. 211 /// Determine if the value is maximal. 212 bool isMaxValue(bool IsSigned) const { 213 if (IsSigned) 214 return Val.isMaxSignedValue(); 215 else 216 return Val.isMaxValue(); 217 } 218 219 /// This function will return true iff this constant represents the smallest 220 /// value that may be represented by this constant's type. 221 /// @returns true if this is the smallest value that may be represented by 222 /// this type. 223 /// Determine if the value is minimal. 224 bool isMinValue(bool IsSigned) const { 225 if (IsSigned) 226 return Val.isMinSignedValue(); 227 else 228 return Val.isMinValue(); 229 } 230 231 /// This function will return true iff this constant represents a value with 232 /// active bits bigger than 64 bits or a value greater than the given uint64_t 233 /// value. 234 /// @returns true iff this constant is greater or equal to the given number. 235 /// Determine if the value is greater or equal to the given number. 236 bool uge(uint64_t Num) const { return Val.uge(Num); } 237 238 /// getLimitedValue - If the value is smaller than the specified limit, 239 /// return it, otherwise return the limit value. This causes the value 240 /// to saturate to the limit. 241 /// @returns the min of the value of the constant and the specified value 242 /// Get the constant's value with a saturation limit 243 uint64_t getLimitedValue(uint64_t Limit = ~0ULL) const { 244 return Val.getLimitedValue(Limit); 245 } 246 247 /// Methods to support type inquiry through isa, cast, and dyn_cast. 248 static bool classof(const Value *V) { 249 return V->getValueID() == ConstantIntVal; 250 } 251 }; 252 253 //===----------------------------------------------------------------------===// 254 /// ConstantFP - Floating Point Values [float, double] 255 /// 256 class ConstantFP final : public ConstantData { 257 friend class Constant; 258 259 APFloat Val; 260 261 ConstantFP(Type *Ty, const APFloat &V); 262 263 void destroyConstantImpl(); 264 265 public: 266 ConstantFP(const ConstantFP &) = delete; 267 268 /// Floating point negation must be implemented with f(x) = -0.0 - x. This 269 /// method returns the negative zero constant for floating point or vector 270 /// floating point types; for all other types, it returns the null value. 271 static Constant *getZeroValueForNegation(Type *Ty); 272 273 /// This returns a ConstantFP, or a vector containing a splat of a ConstantFP, 274 /// for the specified value in the specified type. This should only be used 275 /// for simple constant values like 2.0/1.0 etc, that are known-valid both as 276 /// host double and as the target format. 277 static Constant *get(Type *Ty, double V); 278 279 /// If Ty is a vector type, return a Constant with a splat of the given 280 /// value. Otherwise return a ConstantFP for the given value. 281 static Constant *get(Type *Ty, const APFloat &V); 282 283 static Constant *get(Type *Ty, StringRef Str); 284 static ConstantFP *get(LLVMContext &Context, const APFloat &V); 285 static Constant *getNaN(Type *Ty, bool Negative = false, 286 uint64_t Payload = 0); 287 static Constant *getQNaN(Type *Ty, bool Negative = false, 288 APInt *Payload = nullptr); 289 static Constant *getSNaN(Type *Ty, bool Negative = false, 290 APInt *Payload = nullptr); 291 static Constant *getZero(Type *Ty, bool Negative = false); 292 static Constant *getNegativeZero(Type *Ty) { return getZero(Ty, true); } 293 static Constant *getInfinity(Type *Ty, bool Negative = false); 294 295 /// Return true if Ty is big enough to represent V. 296 static bool isValueValidForType(Type *Ty, const APFloat &V); 297 inline const APFloat &getValueAPF() const { return Val; } 298 inline const APFloat &getValue() const { return Val; } 299 300 /// Return true if the value is positive or negative zero. 301 bool isZero() const { return Val.isZero(); } 302 303 /// Return true if the sign bit is set. 304 bool isNegative() const { return Val.isNegative(); } 305 306 /// Return true if the value is infinity 307 bool isInfinity() const { return Val.isInfinity(); } 308 309 /// Return true if the value is a NaN. 310 bool isNaN() const { return Val.isNaN(); } 311 312 /// We don't rely on operator== working on double values, as it returns true 313 /// for things that are clearly not equal, like -0.0 and 0.0. 314 /// As such, this method can be used to do an exact bit-for-bit comparison of 315 /// two floating point values. The version with a double operand is retained 316 /// because it's so convenient to write isExactlyValue(2.0), but please use 317 /// it only for simple constants. 318 bool isExactlyValue(const APFloat &V) const; 319 320 bool isExactlyValue(double V) const { 321 bool ignored; 322 APFloat FV(V); 323 FV.convert(Val.getSemantics(), APFloat::rmNearestTiesToEven, &ignored); 324 return isExactlyValue(FV); 325 } 326 327 /// Methods for support type inquiry through isa, cast, and dyn_cast: 328 static bool classof(const Value *V) { 329 return V->getValueID() == ConstantFPVal; 330 } 331 }; 332 333 //===----------------------------------------------------------------------===// 334 /// All zero aggregate value 335 /// 336 class ConstantAggregateZero final : public ConstantData { 337 friend class Constant; 338 339 explicit ConstantAggregateZero(Type *Ty) 340 : ConstantData(Ty, ConstantAggregateZeroVal) {} 341 342 void destroyConstantImpl(); 343 344 public: 345 ConstantAggregateZero(const ConstantAggregateZero &) = delete; 346 347 static ConstantAggregateZero *get(Type *Ty); 348 349 /// If this CAZ has array or vector type, return a zero with the right element 350 /// type. 351 Constant *getSequentialElement() const; 352 353 /// If this CAZ has struct type, return a zero with the right element type for 354 /// the specified element. 355 Constant *getStructElement(unsigned Elt) const; 356 357 /// Return a zero of the right value for the specified GEP index if we can, 358 /// otherwise return null (e.g. if C is a ConstantExpr). 359 Constant *getElementValue(Constant *C) const; 360 361 /// Return a zero of the right value for the specified GEP index. 362 Constant *getElementValue(unsigned Idx) const; 363 364 /// Return the number of elements in the array, vector, or struct. 365 ElementCount getElementCount() const; 366 367 /// Methods for support type inquiry through isa, cast, and dyn_cast: 368 /// 369 static bool classof(const Value *V) { 370 return V->getValueID() == ConstantAggregateZeroVal; 371 } 372 }; 373 374 /// Base class for aggregate constants (with operands). 375 /// 376 /// These constants are aggregates of other constants, which are stored as 377 /// operands. 378 /// 379 /// Subclasses are \a ConstantStruct, \a ConstantArray, and \a 380 /// ConstantVector. 381 /// 382 /// \note Some subclasses of \a ConstantData are semantically aggregates -- 383 /// such as \a ConstantDataArray -- but are not subclasses of this because they 384 /// use operands. 385 class ConstantAggregate : public Constant { 386 protected: 387 ConstantAggregate(Type *T, ValueTy VT, ArrayRef<Constant *> V); 388 389 public: 390 /// Transparently provide more efficient getOperand methods. 391 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant); 392 393 /// Methods for support type inquiry through isa, cast, and dyn_cast: 394 static bool classof(const Value *V) { 395 return V->getValueID() >= ConstantAggregateFirstVal && 396 V->getValueID() <= ConstantAggregateLastVal; 397 } 398 }; 399 400 template <> 401 struct OperandTraits<ConstantAggregate> 402 : public VariadicOperandTraits<ConstantAggregate> {}; 403 404 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantAggregate, Constant) 405 406 //===----------------------------------------------------------------------===// 407 /// ConstantArray - Constant Array Declarations 408 /// 409 class ConstantArray final : public ConstantAggregate { 410 friend struct ConstantAggrKeyType<ConstantArray>; 411 friend class Constant; 412 413 ConstantArray(ArrayType *T, ArrayRef<Constant *> Val); 414 415 void destroyConstantImpl(); 416 Value *handleOperandChangeImpl(Value *From, Value *To); 417 418 public: 419 // ConstantArray accessors 420 static Constant *get(ArrayType *T, ArrayRef<Constant *> V); 421 422 private: 423 static Constant *getImpl(ArrayType *T, ArrayRef<Constant *> V); 424 425 public: 426 /// Specialize the getType() method to always return an ArrayType, 427 /// which reduces the amount of casting needed in parts of the compiler. 428 inline ArrayType *getType() const { 429 return cast<ArrayType>(Value::getType()); 430 } 431 432 /// Methods for support type inquiry through isa, cast, and dyn_cast: 433 static bool classof(const Value *V) { 434 return V->getValueID() == ConstantArrayVal; 435 } 436 }; 437 438 //===----------------------------------------------------------------------===// 439 // Constant Struct Declarations 440 // 441 class ConstantStruct final : public ConstantAggregate { 442 friend struct ConstantAggrKeyType<ConstantStruct>; 443 friend class Constant; 444 445 ConstantStruct(StructType *T, ArrayRef<Constant *> Val); 446 447 void destroyConstantImpl(); 448 Value *handleOperandChangeImpl(Value *From, Value *To); 449 450 public: 451 // ConstantStruct accessors 452 static Constant *get(StructType *T, ArrayRef<Constant *> V); 453 454 template <typename... Csts> 455 static std::enable_if_t<are_base_of<Constant, Csts...>::value, Constant *> 456 get(StructType *T, Csts *...Vs) { 457 return get(T, ArrayRef<Constant *>({Vs...})); 458 } 459 460 /// Return an anonymous struct that has the specified elements. 461 /// If the struct is possibly empty, then you must specify a context. 462 static Constant *getAnon(ArrayRef<Constant *> V, bool Packed = false) { 463 return get(getTypeForElements(V, Packed), V); 464 } 465 static Constant *getAnon(LLVMContext &Ctx, ArrayRef<Constant *> V, 466 bool Packed = false) { 467 return get(getTypeForElements(Ctx, V, Packed), V); 468 } 469 470 /// Return an anonymous struct type to use for a constant with the specified 471 /// set of elements. The list must not be empty. 472 static StructType *getTypeForElements(ArrayRef<Constant *> V, 473 bool Packed = false); 474 /// This version of the method allows an empty list. 475 static StructType *getTypeForElements(LLVMContext &Ctx, 476 ArrayRef<Constant *> V, 477 bool Packed = false); 478 479 /// Specialization - reduce amount of casting. 480 inline StructType *getType() const { 481 return cast<StructType>(Value::getType()); 482 } 483 484 /// Methods for support type inquiry through isa, cast, and dyn_cast: 485 static bool classof(const Value *V) { 486 return V->getValueID() == ConstantStructVal; 487 } 488 }; 489 490 //===----------------------------------------------------------------------===// 491 /// Constant Vector Declarations 492 /// 493 class ConstantVector final : public ConstantAggregate { 494 friend struct ConstantAggrKeyType<ConstantVector>; 495 friend class Constant; 496 497 ConstantVector(VectorType *T, ArrayRef<Constant *> Val); 498 499 void destroyConstantImpl(); 500 Value *handleOperandChangeImpl(Value *From, Value *To); 501 502 public: 503 // ConstantVector accessors 504 static Constant *get(ArrayRef<Constant *> V); 505 506 private: 507 static Constant *getImpl(ArrayRef<Constant *> V); 508 509 public: 510 /// Return a ConstantVector with the specified constant in each element. 511 /// Note that this might not return an instance of ConstantVector 512 static Constant *getSplat(ElementCount EC, Constant *Elt); 513 514 /// Specialize the getType() method to always return a FixedVectorType, 515 /// which reduces the amount of casting needed in parts of the compiler. 516 inline FixedVectorType *getType() const { 517 return cast<FixedVectorType>(Value::getType()); 518 } 519 520 /// If all elements of the vector constant have the same value, return that 521 /// value. Otherwise, return nullptr. Ignore undefined elements by setting 522 /// AllowUndefs to true. 523 Constant *getSplatValue(bool AllowUndefs = false) const; 524 525 /// Methods for support type inquiry through isa, cast, and dyn_cast: 526 static bool classof(const Value *V) { 527 return V->getValueID() == ConstantVectorVal; 528 } 529 }; 530 531 //===----------------------------------------------------------------------===// 532 /// A constant pointer value that points to null 533 /// 534 class ConstantPointerNull final : public ConstantData { 535 friend class Constant; 536 537 explicit ConstantPointerNull(PointerType *T) 538 : ConstantData(T, Value::ConstantPointerNullVal) {} 539 540 void destroyConstantImpl(); 541 542 public: 543 ConstantPointerNull(const ConstantPointerNull &) = delete; 544 545 /// Static factory methods - Return objects of the specified value 546 static ConstantPointerNull *get(PointerType *T); 547 548 /// Specialize the getType() method to always return an PointerType, 549 /// which reduces the amount of casting needed in parts of the compiler. 550 inline PointerType *getType() const { 551 return cast<PointerType>(Value::getType()); 552 } 553 554 /// Methods for support type inquiry through isa, cast, and dyn_cast: 555 static bool classof(const Value *V) { 556 return V->getValueID() == ConstantPointerNullVal; 557 } 558 }; 559 560 //===----------------------------------------------------------------------===// 561 /// ConstantDataSequential - A vector or array constant whose element type is a 562 /// simple 1/2/4/8-byte integer or half/bfloat/float/double, and whose elements 563 /// are just simple data values (i.e. ConstantInt/ConstantFP). This Constant 564 /// node has no operands because it stores all of the elements of the constant 565 /// as densely packed data, instead of as Value*'s. 566 /// 567 /// This is the common base class of ConstantDataArray and ConstantDataVector. 568 /// 569 class ConstantDataSequential : public ConstantData { 570 friend class LLVMContextImpl; 571 friend class Constant; 572 573 /// A pointer to the bytes underlying this constant (which is owned by the 574 /// uniquing StringMap). 575 const char *DataElements; 576 577 /// This forms a link list of ConstantDataSequential nodes that have 578 /// the same value but different type. For example, 0,0,0,1 could be a 4 579 /// element array of i8, or a 1-element array of i32. They'll both end up in 580 /// the same StringMap bucket, linked up. 581 std::unique_ptr<ConstantDataSequential> Next; 582 583 void destroyConstantImpl(); 584 585 protected: 586 explicit ConstantDataSequential(Type *ty, ValueTy VT, const char *Data) 587 : ConstantData(ty, VT), DataElements(Data) {} 588 589 static Constant *getImpl(StringRef Bytes, Type *Ty); 590 591 public: 592 ConstantDataSequential(const ConstantDataSequential &) = delete; 593 594 /// Return true if a ConstantDataSequential can be formed with a vector or 595 /// array of the specified element type. 596 /// ConstantDataArray only works with normal float and int types that are 597 /// stored densely in memory, not with things like i42 or x86_f80. 598 static bool isElementTypeCompatible(Type *Ty); 599 600 /// If this is a sequential container of integers (of any size), return the 601 /// specified element in the low bits of a uint64_t. 602 uint64_t getElementAsInteger(unsigned i) const; 603 604 /// If this is a sequential container of integers (of any size), return the 605 /// specified element as an APInt. 606 APInt getElementAsAPInt(unsigned i) const; 607 608 /// If this is a sequential container of floating point type, return the 609 /// specified element as an APFloat. 610 APFloat getElementAsAPFloat(unsigned i) const; 611 612 /// If this is an sequential container of floats, return the specified element 613 /// as a float. 614 float getElementAsFloat(unsigned i) const; 615 616 /// If this is an sequential container of doubles, return the specified 617 /// element as a double. 618 double getElementAsDouble(unsigned i) const; 619 620 /// Return a Constant for a specified index's element. 621 /// Note that this has to compute a new constant to return, so it isn't as 622 /// efficient as getElementAsInteger/Float/Double. 623 Constant *getElementAsConstant(unsigned i) const; 624 625 /// Return the element type of the array/vector. 626 Type *getElementType() const; 627 628 /// Return the number of elements in the array or vector. 629 unsigned getNumElements() const; 630 631 /// Return the size (in bytes) of each element in the array/vector. 632 /// The size of the elements is known to be a multiple of one byte. 633 uint64_t getElementByteSize() const; 634 635 /// This method returns true if this is an array of \p CharSize integers. 636 bool isString(unsigned CharSize = 8) const; 637 638 /// This method returns true if the array "isString", ends with a null byte, 639 /// and does not contains any other null bytes. 640 bool isCString() const; 641 642 /// If this array is isString(), then this method returns the array as a 643 /// StringRef. Otherwise, it asserts out. 644 StringRef getAsString() const { 645 assert(isString() && "Not a string"); 646 return getRawDataValues(); 647 } 648 649 /// If this array is isCString(), then this method returns the array (without 650 /// the trailing null byte) as a StringRef. Otherwise, it asserts out. 651 StringRef getAsCString() const { 652 assert(isCString() && "Isn't a C string"); 653 StringRef Str = getAsString(); 654 return Str.substr(0, Str.size() - 1); 655 } 656 657 /// Return the raw, underlying, bytes of this data. Note that this is an 658 /// extremely tricky thing to work with, as it exposes the host endianness of 659 /// the data elements. 660 StringRef getRawDataValues() const; 661 662 /// Methods for support type inquiry through isa, cast, and dyn_cast: 663 static bool classof(const Value *V) { 664 return V->getValueID() == ConstantDataArrayVal || 665 V->getValueID() == ConstantDataVectorVal; 666 } 667 668 private: 669 const char *getElementPointer(unsigned Elt) const; 670 }; 671 672 //===----------------------------------------------------------------------===// 673 /// An array constant whose element type is a simple 1/2/4/8-byte integer or 674 /// float/double, and whose elements are just simple data values 675 /// (i.e. ConstantInt/ConstantFP). This Constant node has no operands because it 676 /// stores all of the elements of the constant as densely packed data, instead 677 /// of as Value*'s. 678 class ConstantDataArray final : public ConstantDataSequential { 679 friend class ConstantDataSequential; 680 681 explicit ConstantDataArray(Type *ty, const char *Data) 682 : ConstantDataSequential(ty, ConstantDataArrayVal, Data) {} 683 684 public: 685 ConstantDataArray(const ConstantDataArray &) = delete; 686 687 /// get() constructor - Return a constant with array type with an element 688 /// count and element type matching the ArrayRef passed in. Note that this 689 /// can return a ConstantAggregateZero object. 690 template <typename ElementTy> 691 static Constant *get(LLVMContext &Context, ArrayRef<ElementTy> Elts) { 692 const char *Data = reinterpret_cast<const char *>(Elts.data()); 693 return getRaw(StringRef(Data, Elts.size() * sizeof(ElementTy)), Elts.size(), 694 Type::getScalarTy<ElementTy>(Context)); 695 } 696 697 /// get() constructor - ArrayTy needs to be compatible with 698 /// ArrayRef<ElementTy>. Calls get(LLVMContext, ArrayRef<ElementTy>). 699 template <typename ArrayTy> 700 static Constant *get(LLVMContext &Context, ArrayTy &Elts) { 701 return ConstantDataArray::get(Context, ArrayRef(Elts)); 702 } 703 704 /// getRaw() constructor - Return a constant with array type with an element 705 /// count and element type matching the NumElements and ElementTy parameters 706 /// passed in. Note that this can return a ConstantAggregateZero object. 707 /// ElementTy must be one of i8/i16/i32/i64/half/bfloat/float/double. Data is 708 /// the buffer containing the elements. Be careful to make sure Data uses the 709 /// right endianness, the buffer will be used as-is. 710 static Constant *getRaw(StringRef Data, uint64_t NumElements, 711 Type *ElementTy) { 712 Type *Ty = ArrayType::get(ElementTy, NumElements); 713 return getImpl(Data, Ty); 714 } 715 716 /// getFP() constructors - Return a constant of array type with a float 717 /// element type taken from argument `ElementType', and count taken from 718 /// argument `Elts'. The amount of bits of the contained type must match the 719 /// number of bits of the type contained in the passed in ArrayRef. 720 /// (i.e. half or bfloat for 16bits, float for 32bits, double for 64bits) Note 721 /// that this can return a ConstantAggregateZero object. 722 static Constant *getFP(Type *ElementType, ArrayRef<uint16_t> Elts); 723 static Constant *getFP(Type *ElementType, ArrayRef<uint32_t> Elts); 724 static Constant *getFP(Type *ElementType, ArrayRef<uint64_t> Elts); 725 726 /// This method constructs a CDS and initializes it with a text string. 727 /// The default behavior (AddNull==true) causes a null terminator to 728 /// be placed at the end of the array (increasing the length of the string by 729 /// one more than the StringRef would normally indicate. Pass AddNull=false 730 /// to disable this behavior. 731 static Constant *getString(LLVMContext &Context, StringRef Initializer, 732 bool AddNull = true); 733 734 /// Specialize the getType() method to always return an ArrayType, 735 /// which reduces the amount of casting needed in parts of the compiler. 736 inline ArrayType *getType() const { 737 return cast<ArrayType>(Value::getType()); 738 } 739 740 /// Methods for support type inquiry through isa, cast, and dyn_cast: 741 static bool classof(const Value *V) { 742 return V->getValueID() == ConstantDataArrayVal; 743 } 744 }; 745 746 //===----------------------------------------------------------------------===// 747 /// A vector constant whose element type is a simple 1/2/4/8-byte integer or 748 /// float/double, and whose elements are just simple data values 749 /// (i.e. ConstantInt/ConstantFP). This Constant node has no operands because it 750 /// stores all of the elements of the constant as densely packed data, instead 751 /// of as Value*'s. 752 class ConstantDataVector final : public ConstantDataSequential { 753 friend class ConstantDataSequential; 754 755 explicit ConstantDataVector(Type *ty, const char *Data) 756 : ConstantDataSequential(ty, ConstantDataVectorVal, Data), 757 IsSplatSet(false) {} 758 // Cache whether or not the constant is a splat. 759 mutable bool IsSplatSet : 1; 760 mutable bool IsSplat : 1; 761 bool isSplatData() const; 762 763 public: 764 ConstantDataVector(const ConstantDataVector &) = delete; 765 766 /// get() constructors - Return a constant with vector type with an element 767 /// count and element type matching the ArrayRef passed in. Note that this 768 /// can return a ConstantAggregateZero object. 769 static Constant *get(LLVMContext &Context, ArrayRef<uint8_t> Elts); 770 static Constant *get(LLVMContext &Context, ArrayRef<uint16_t> Elts); 771 static Constant *get(LLVMContext &Context, ArrayRef<uint32_t> Elts); 772 static Constant *get(LLVMContext &Context, ArrayRef<uint64_t> Elts); 773 static Constant *get(LLVMContext &Context, ArrayRef<float> Elts); 774 static Constant *get(LLVMContext &Context, ArrayRef<double> Elts); 775 776 /// getRaw() constructor - Return a constant with vector type with an element 777 /// count and element type matching the NumElements and ElementTy parameters 778 /// passed in. Note that this can return a ConstantAggregateZero object. 779 /// ElementTy must be one of i8/i16/i32/i64/half/bfloat/float/double. Data is 780 /// the buffer containing the elements. Be careful to make sure Data uses the 781 /// right endianness, the buffer will be used as-is. 782 static Constant *getRaw(StringRef Data, uint64_t NumElements, 783 Type *ElementTy) { 784 Type *Ty = VectorType::get(ElementTy, ElementCount::getFixed(NumElements)); 785 return getImpl(Data, Ty); 786 } 787 788 /// getFP() constructors - Return a constant of vector type with a float 789 /// element type taken from argument `ElementType', and count taken from 790 /// argument `Elts'. The amount of bits of the contained type must match the 791 /// number of bits of the type contained in the passed in ArrayRef. 792 /// (i.e. half or bfloat for 16bits, float for 32bits, double for 64bits) Note 793 /// that this can return a ConstantAggregateZero object. 794 static Constant *getFP(Type *ElementType, ArrayRef<uint16_t> Elts); 795 static Constant *getFP(Type *ElementType, ArrayRef<uint32_t> Elts); 796 static Constant *getFP(Type *ElementType, ArrayRef<uint64_t> Elts); 797 798 /// Return a ConstantVector with the specified constant in each element. 799 /// The specified constant has to be a of a compatible type (i8/i16/ 800 /// i32/i64/half/bfloat/float/double) and must be a ConstantFP or ConstantInt. 801 static Constant *getSplat(unsigned NumElts, Constant *Elt); 802 803 /// Returns true if this is a splat constant, meaning that all elements have 804 /// the same value. 805 bool isSplat() const; 806 807 /// If this is a splat constant, meaning that all of the elements have the 808 /// same value, return that value. Otherwise return NULL. 809 Constant *getSplatValue() const; 810 811 /// Specialize the getType() method to always return a FixedVectorType, 812 /// which reduces the amount of casting needed in parts of the compiler. 813 inline FixedVectorType *getType() const { 814 return cast<FixedVectorType>(Value::getType()); 815 } 816 817 /// Methods for support type inquiry through isa, cast, and dyn_cast: 818 static bool classof(const Value *V) { 819 return V->getValueID() == ConstantDataVectorVal; 820 } 821 }; 822 823 //===----------------------------------------------------------------------===// 824 /// A constant token which is empty 825 /// 826 class ConstantTokenNone final : public ConstantData { 827 friend class Constant; 828 829 explicit ConstantTokenNone(LLVMContext &Context) 830 : ConstantData(Type::getTokenTy(Context), ConstantTokenNoneVal) {} 831 832 void destroyConstantImpl(); 833 834 public: 835 ConstantTokenNone(const ConstantTokenNone &) = delete; 836 837 /// Return the ConstantTokenNone. 838 static ConstantTokenNone *get(LLVMContext &Context); 839 840 /// Methods to support type inquiry through isa, cast, and dyn_cast. 841 static bool classof(const Value *V) { 842 return V->getValueID() == ConstantTokenNoneVal; 843 } 844 }; 845 846 /// A constant target extension type default initializer 847 class ConstantTargetNone final : public ConstantData { 848 friend class Constant; 849 850 explicit ConstantTargetNone(TargetExtType *T) 851 : ConstantData(T, Value::ConstantTargetNoneVal) {} 852 853 void destroyConstantImpl(); 854 855 public: 856 ConstantTargetNone(const ConstantTargetNone &) = delete; 857 858 /// Static factory methods - Return objects of the specified value. 859 static ConstantTargetNone *get(TargetExtType *T); 860 861 /// Specialize the getType() method to always return an TargetExtType, 862 /// which reduces the amount of casting needed in parts of the compiler. 863 inline TargetExtType *getType() const { 864 return cast<TargetExtType>(Value::getType()); 865 } 866 867 /// Methods for support type inquiry through isa, cast, and dyn_cast. 868 static bool classof(const Value *V) { 869 return V->getValueID() == ConstantTargetNoneVal; 870 } 871 }; 872 873 /// The address of a basic block. 874 /// 875 class BlockAddress final : public Constant { 876 friend class Constant; 877 878 BlockAddress(Function *F, BasicBlock *BB); 879 880 void *operator new(size_t S) { return User::operator new(S, 2); } 881 882 void destroyConstantImpl(); 883 Value *handleOperandChangeImpl(Value *From, Value *To); 884 885 public: 886 void operator delete(void *Ptr) { User::operator delete(Ptr); } 887 888 /// Return a BlockAddress for the specified function and basic block. 889 static BlockAddress *get(Function *F, BasicBlock *BB); 890 891 /// Return a BlockAddress for the specified basic block. The basic 892 /// block must be embedded into a function. 893 static BlockAddress *get(BasicBlock *BB); 894 895 /// Lookup an existing \c BlockAddress constant for the given BasicBlock. 896 /// 897 /// \returns 0 if \c !BB->hasAddressTaken(), otherwise the \c BlockAddress. 898 static BlockAddress *lookup(const BasicBlock *BB); 899 900 /// Transparently provide more efficient getOperand methods. 901 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value); 902 903 Function *getFunction() const { return (Function *)Op<0>().get(); } 904 BasicBlock *getBasicBlock() const { return (BasicBlock *)Op<1>().get(); } 905 906 /// Methods for support type inquiry through isa, cast, and dyn_cast: 907 static bool classof(const Value *V) { 908 return V->getValueID() == BlockAddressVal; 909 } 910 }; 911 912 template <> 913 struct OperandTraits<BlockAddress> 914 : public FixedNumOperandTraits<BlockAddress, 2> {}; 915 916 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(BlockAddress, Value) 917 918 /// Wrapper for a function that represents a value that 919 /// functionally represents the original function. This can be a function, 920 /// global alias to a function, or an ifunc. 921 class DSOLocalEquivalent final : public Constant { 922 friend class Constant; 923 924 DSOLocalEquivalent(GlobalValue *GV); 925 926 void *operator new(size_t S) { return User::operator new(S, 1); } 927 928 void destroyConstantImpl(); 929 Value *handleOperandChangeImpl(Value *From, Value *To); 930 931 public: 932 void operator delete(void *Ptr) { User::operator delete(Ptr); } 933 934 /// Return a DSOLocalEquivalent for the specified global value. 935 static DSOLocalEquivalent *get(GlobalValue *GV); 936 937 /// Transparently provide more efficient getOperand methods. 938 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value); 939 940 GlobalValue *getGlobalValue() const { 941 return cast<GlobalValue>(Op<0>().get()); 942 } 943 944 /// Methods for support type inquiry through isa, cast, and dyn_cast: 945 static bool classof(const Value *V) { 946 return V->getValueID() == DSOLocalEquivalentVal; 947 } 948 }; 949 950 template <> 951 struct OperandTraits<DSOLocalEquivalent> 952 : public FixedNumOperandTraits<DSOLocalEquivalent, 1> {}; 953 954 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(DSOLocalEquivalent, Value) 955 956 /// Wrapper for a value that won't be replaced with a CFI jump table 957 /// pointer in LowerTypeTestsModule. 958 class NoCFIValue final : public Constant { 959 friend class Constant; 960 961 NoCFIValue(GlobalValue *GV); 962 963 void *operator new(size_t S) { return User::operator new(S, 1); } 964 965 void destroyConstantImpl(); 966 Value *handleOperandChangeImpl(Value *From, Value *To); 967 968 public: 969 /// Return a NoCFIValue for the specified function. 970 static NoCFIValue *get(GlobalValue *GV); 971 972 /// Transparently provide more efficient getOperand methods. 973 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value); 974 975 GlobalValue *getGlobalValue() const { 976 return cast<GlobalValue>(Op<0>().get()); 977 } 978 979 /// Methods for support type inquiry through isa, cast, and dyn_cast: 980 static bool classof(const Value *V) { 981 return V->getValueID() == NoCFIValueVal; 982 } 983 }; 984 985 template <> 986 struct OperandTraits<NoCFIValue> : public FixedNumOperandTraits<NoCFIValue, 1> { 987 }; 988 989 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(NoCFIValue, Value) 990 991 //===----------------------------------------------------------------------===// 992 /// A constant value that is initialized with an expression using 993 /// other constant values. 994 /// 995 /// This class uses the standard Instruction opcodes to define the various 996 /// constant expressions. The Opcode field for the ConstantExpr class is 997 /// maintained in the Value::SubclassData field. 998 class ConstantExpr : public Constant { 999 friend struct ConstantExprKeyType; 1000 friend class Constant; 1001 1002 void destroyConstantImpl(); 1003 Value *handleOperandChangeImpl(Value *From, Value *To); 1004 1005 protected: 1006 ConstantExpr(Type *ty, unsigned Opcode, Use *Ops, unsigned NumOps) 1007 : Constant(ty, ConstantExprVal, Ops, NumOps) { 1008 // Operation type (an Instruction opcode) is stored as the SubclassData. 1009 setValueSubclassData(Opcode); 1010 } 1011 1012 ~ConstantExpr() = default; 1013 1014 public: 1015 // Static methods to construct a ConstantExpr of different kinds. Note that 1016 // these methods may return a object that is not an instance of the 1017 // ConstantExpr class, because they will attempt to fold the constant 1018 // expression into something simpler if possible. 1019 1020 /// getAlignOf constant expr - computes the alignment of a type in a target 1021 /// independent way (Note: the return type is an i64). 1022 static Constant *getAlignOf(Type *Ty); 1023 1024 /// getSizeOf constant expr - computes the (alloc) size of a type (in 1025 /// address-units, not bits) in a target independent way (Note: the return 1026 /// type is an i64). 1027 /// 1028 static Constant *getSizeOf(Type *Ty); 1029 1030 /// getOffsetOf constant expr - computes the offset of a struct field in a 1031 /// target independent way (Note: the return type is an i64). 1032 /// 1033 static Constant *getOffsetOf(StructType *STy, unsigned FieldNo); 1034 1035 /// getOffsetOf constant expr - This is a generalized form of getOffsetOf, 1036 /// which supports any aggregate type, and any Constant index. 1037 /// 1038 static Constant *getOffsetOf(Type *Ty, Constant *FieldNo); 1039 1040 static Constant *getNeg(Constant *C, bool HasNUW = false, 1041 bool HasNSW = false); 1042 static Constant *getNot(Constant *C); 1043 static Constant *getAdd(Constant *C1, Constant *C2, bool HasNUW = false, 1044 bool HasNSW = false); 1045 static Constant *getSub(Constant *C1, Constant *C2, bool HasNUW = false, 1046 bool HasNSW = false); 1047 static Constant *getMul(Constant *C1, Constant *C2, bool HasNUW = false, 1048 bool HasNSW = false); 1049 static Constant *getAnd(Constant *C1, Constant *C2); 1050 static Constant *getOr(Constant *C1, Constant *C2); 1051 static Constant *getXor(Constant *C1, Constant *C2); 1052 static Constant *getUMin(Constant *C1, Constant *C2); 1053 static Constant *getShl(Constant *C1, Constant *C2, bool HasNUW = false, 1054 bool HasNSW = false); 1055 static Constant *getLShr(Constant *C1, Constant *C2, bool isExact = false); 1056 static Constant *getAShr(Constant *C1, Constant *C2, bool isExact = false); 1057 static Constant *getTrunc(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1058 static Constant *getSExt(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1059 static Constant *getZExt(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1060 static Constant *getFPTrunc(Constant *C, Type *Ty, 1061 bool OnlyIfReduced = false); 1062 static Constant *getFPExtend(Constant *C, Type *Ty, 1063 bool OnlyIfReduced = false); 1064 static Constant *getUIToFP(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1065 static Constant *getSIToFP(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1066 static Constant *getFPToUI(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1067 static Constant *getFPToSI(Constant *C, Type *Ty, bool OnlyIfReduced = false); 1068 static Constant *getPtrToInt(Constant *C, Type *Ty, 1069 bool OnlyIfReduced = false); 1070 static Constant *getIntToPtr(Constant *C, Type *Ty, 1071 bool OnlyIfReduced = false); 1072 static Constant *getBitCast(Constant *C, Type *Ty, 1073 bool OnlyIfReduced = false); 1074 static Constant *getAddrSpaceCast(Constant *C, Type *Ty, 1075 bool OnlyIfReduced = false); 1076 1077 static Constant *getNSWNeg(Constant *C) { return getNeg(C, false, true); } 1078 static Constant *getNUWNeg(Constant *C) { return getNeg(C, true, false); } 1079 1080 static Constant *getNSWAdd(Constant *C1, Constant *C2) { 1081 return getAdd(C1, C2, false, true); 1082 } 1083 1084 static Constant *getNUWAdd(Constant *C1, Constant *C2) { 1085 return getAdd(C1, C2, true, false); 1086 } 1087 1088 static Constant *getNSWSub(Constant *C1, Constant *C2) { 1089 return getSub(C1, C2, false, true); 1090 } 1091 1092 static Constant *getNUWSub(Constant *C1, Constant *C2) { 1093 return getSub(C1, C2, true, false); 1094 } 1095 1096 static Constant *getNSWMul(Constant *C1, Constant *C2) { 1097 return getMul(C1, C2, false, true); 1098 } 1099 1100 static Constant *getNUWMul(Constant *C1, Constant *C2) { 1101 return getMul(C1, C2, true, false); 1102 } 1103 1104 static Constant *getNSWShl(Constant *C1, Constant *C2) { 1105 return getShl(C1, C2, false, true); 1106 } 1107 1108 static Constant *getNUWShl(Constant *C1, Constant *C2) { 1109 return getShl(C1, C2, true, false); 1110 } 1111 1112 static Constant *getExactAShr(Constant *C1, Constant *C2) { 1113 return getAShr(C1, C2, true); 1114 } 1115 1116 static Constant *getExactLShr(Constant *C1, Constant *C2) { 1117 return getLShr(C1, C2, true); 1118 } 1119 1120 /// If C is a scalar/fixed width vector of known powers of 2, then this 1121 /// function returns a new scalar/fixed width vector obtained from logBase2 1122 /// of C. Undef vector elements are set to zero. 1123 /// Return a null pointer otherwise. 1124 static Constant *getExactLogBase2(Constant *C); 1125 1126 /// Return the identity constant for a binary opcode. 1127 /// The identity constant C is defined as X op C = X and C op X = X for every 1128 /// X when the binary operation is commutative. If the binop is not 1129 /// commutative, callers can acquire the operand 1 identity constant by 1130 /// setting AllowRHSConstant to true. For example, any shift has a zero 1131 /// identity constant for operand 1: X shift 0 = X. 1132 /// If this is a fadd/fsub operation and we don't care about signed zeros, 1133 /// then setting NSZ to true returns the identity +0.0 instead of -0.0. 1134 /// Return nullptr if the operator does not have an identity constant. 1135 static Constant *getBinOpIdentity(unsigned Opcode, Type *Ty, 1136 bool AllowRHSConstant = false, 1137 bool NSZ = false); 1138 1139 /// Return the absorbing element for the given binary 1140 /// operation, i.e. a constant C such that X op C = C and C op X = C for 1141 /// every X. For example, this returns zero for integer multiplication. 1142 /// It returns null if the operator doesn't have an absorbing element. 1143 static Constant *getBinOpAbsorber(unsigned Opcode, Type *Ty); 1144 1145 /// Transparently provide more efficient getOperand methods. 1146 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant); 1147 1148 /// Convenience function for getting a Cast operation. 1149 /// 1150 /// \param ops The opcode for the conversion 1151 /// \param C The constant to be converted 1152 /// \param Ty The type to which the constant is converted 1153 /// \param OnlyIfReduced see \a getWithOperands() docs. 1154 static Constant *getCast(unsigned ops, Constant *C, Type *Ty, 1155 bool OnlyIfReduced = false); 1156 1157 // Create a ZExt or BitCast cast constant expression 1158 static Constant * 1159 getZExtOrBitCast(Constant *C, ///< The constant to zext or bitcast 1160 Type *Ty ///< The type to zext or bitcast C to 1161 ); 1162 1163 // Create a SExt or BitCast cast constant expression 1164 static Constant * 1165 getSExtOrBitCast(Constant *C, ///< The constant to sext or bitcast 1166 Type *Ty ///< The type to sext or bitcast C to 1167 ); 1168 1169 // Create a Trunc or BitCast cast constant expression 1170 static Constant * 1171 getTruncOrBitCast(Constant *C, ///< The constant to trunc or bitcast 1172 Type *Ty ///< The type to trunc or bitcast C to 1173 ); 1174 1175 /// Create either an sext, trunc or nothing, depending on whether Ty is 1176 /// wider, narrower or the same as C->getType(). This only works with 1177 /// integer or vector of integer types. 1178 static Constant *getSExtOrTrunc(Constant *C, Type *Ty); 1179 1180 /// Create a BitCast, AddrSpaceCast, or a PtrToInt cast constant 1181 /// expression. 1182 static Constant * 1183 getPointerCast(Constant *C, ///< The pointer value to be casted (operand 0) 1184 Type *Ty ///< The type to which cast should be made 1185 ); 1186 1187 /// Create a BitCast or AddrSpaceCast for a pointer type depending on 1188 /// the address space. 1189 static Constant *getPointerBitCastOrAddrSpaceCast( 1190 Constant *C, ///< The constant to addrspacecast or bitcast 1191 Type *Ty ///< The type to bitcast or addrspacecast C to 1192 ); 1193 1194 /// Create a ZExt, Bitcast or Trunc for integer -> integer casts 1195 static Constant * 1196 getIntegerCast(Constant *C, ///< The integer constant to be casted 1197 Type *Ty, ///< The integer type to cast to 1198 bool IsSigned ///< Whether C should be treated as signed or not 1199 ); 1200 1201 /// Create a FPExt, Bitcast or FPTrunc for fp -> fp casts 1202 static Constant *getFPCast(Constant *C, ///< The integer constant to be casted 1203 Type *Ty ///< The integer type to cast to 1204 ); 1205 1206 /// Return true if this is a convert constant expression 1207 bool isCast() const; 1208 1209 /// Return true if this is a compare constant expression 1210 bool isCompare() const; 1211 1212 /// Select constant expr 1213 /// 1214 /// \param OnlyIfReducedTy see \a getWithOperands() docs. 1215 static Constant *getSelect(Constant *C, Constant *V1, Constant *V2, 1216 Type *OnlyIfReducedTy = nullptr); 1217 1218 /// get - Return a binary or shift operator constant expression, 1219 /// folding if possible. 1220 /// 1221 /// \param OnlyIfReducedTy see \a getWithOperands() docs. 1222 static Constant *get(unsigned Opcode, Constant *C1, Constant *C2, 1223 unsigned Flags = 0, Type *OnlyIfReducedTy = nullptr); 1224 1225 /// Return an ICmp or FCmp comparison operator constant expression. 1226 /// 1227 /// \param OnlyIfReduced see \a getWithOperands() docs. 1228 static Constant *getCompare(unsigned short pred, Constant *C1, Constant *C2, 1229 bool OnlyIfReduced = false); 1230 1231 /// get* - Return some common constants without having to 1232 /// specify the full Instruction::OPCODE identifier. 1233 /// 1234 static Constant *getICmp(unsigned short pred, Constant *LHS, Constant *RHS, 1235 bool OnlyIfReduced = false); 1236 static Constant *getFCmp(unsigned short pred, Constant *LHS, Constant *RHS, 1237 bool OnlyIfReduced = false); 1238 1239 /// Getelementptr form. Value* is only accepted for convenience; 1240 /// all elements must be Constants. 1241 /// 1242 /// \param InRangeIndex the inrange index if present or std::nullopt. 1243 /// \param OnlyIfReducedTy see \a getWithOperands() docs. 1244 static Constant * 1245 getGetElementPtr(Type *Ty, Constant *C, ArrayRef<Constant *> IdxList, 1246 bool InBounds = false, 1247 std::optional<unsigned> InRangeIndex = std::nullopt, 1248 Type *OnlyIfReducedTy = nullptr) { 1249 return getGetElementPtr( 1250 Ty, C, ArrayRef((Value *const *)IdxList.data(), IdxList.size()), 1251 InBounds, InRangeIndex, OnlyIfReducedTy); 1252 } 1253 static Constant * 1254 getGetElementPtr(Type *Ty, Constant *C, Constant *Idx, bool InBounds = false, 1255 std::optional<unsigned> InRangeIndex = std::nullopt, 1256 Type *OnlyIfReducedTy = nullptr) { 1257 // This form of the function only exists to avoid ambiguous overload 1258 // warnings about whether to convert Idx to ArrayRef<Constant *> or 1259 // ArrayRef<Value *>. 1260 return getGetElementPtr(Ty, C, cast<Value>(Idx), InBounds, InRangeIndex, 1261 OnlyIfReducedTy); 1262 } 1263 static Constant * 1264 getGetElementPtr(Type *Ty, Constant *C, ArrayRef<Value *> IdxList, 1265 bool InBounds = false, 1266 std::optional<unsigned> InRangeIndex = std::nullopt, 1267 Type *OnlyIfReducedTy = nullptr); 1268 1269 /// Create an "inbounds" getelementptr. See the documentation for the 1270 /// "inbounds" flag in LangRef.html for details. 1271 static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C, 1272 ArrayRef<Constant *> IdxList) { 1273 return getGetElementPtr(Ty, C, IdxList, true); 1274 } 1275 static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C, 1276 Constant *Idx) { 1277 // This form of the function only exists to avoid ambiguous overload 1278 // warnings about whether to convert Idx to ArrayRef<Constant *> or 1279 // ArrayRef<Value *>. 1280 return getGetElementPtr(Ty, C, Idx, true); 1281 } 1282 static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C, 1283 ArrayRef<Value *> IdxList) { 1284 return getGetElementPtr(Ty, C, IdxList, true); 1285 } 1286 1287 static Constant *getExtractElement(Constant *Vec, Constant *Idx, 1288 Type *OnlyIfReducedTy = nullptr); 1289 static Constant *getInsertElement(Constant *Vec, Constant *Elt, Constant *Idx, 1290 Type *OnlyIfReducedTy = nullptr); 1291 static Constant *getShuffleVector(Constant *V1, Constant *V2, 1292 ArrayRef<int> Mask, 1293 Type *OnlyIfReducedTy = nullptr); 1294 1295 /// Return the opcode at the root of this constant expression 1296 unsigned getOpcode() const { return getSubclassDataFromValue(); } 1297 1298 /// Return the ICMP or FCMP predicate value. Assert if this is not an ICMP or 1299 /// FCMP constant expression. 1300 unsigned getPredicate() const; 1301 1302 /// Assert that this is a shufflevector and return the mask. See class 1303 /// ShuffleVectorInst for a description of the mask representation. 1304 ArrayRef<int> getShuffleMask() const; 1305 1306 /// Assert that this is a shufflevector and return the mask. 1307 /// 1308 /// TODO: This is a temporary hack until we update the bitcode format for 1309 /// shufflevector. 1310 Constant *getShuffleMaskForBitcode() const; 1311 1312 /// Return a string representation for an opcode. 1313 const char *getOpcodeName() const; 1314 1315 /// This returns the current constant expression with the operands replaced 1316 /// with the specified values. The specified array must have the same number 1317 /// of operands as our current one. 1318 Constant *getWithOperands(ArrayRef<Constant *> Ops) const { 1319 return getWithOperands(Ops, getType()); 1320 } 1321 1322 /// Get the current expression with the operands replaced. 1323 /// 1324 /// Return the current constant expression with the operands replaced with \c 1325 /// Ops and the type with \c Ty. The new operands must have the same number 1326 /// as the current ones. 1327 /// 1328 /// If \c OnlyIfReduced is \c true, nullptr will be returned unless something 1329 /// gets constant-folded, the type changes, or the expression is otherwise 1330 /// canonicalized. This parameter should almost always be \c false. 1331 Constant *getWithOperands(ArrayRef<Constant *> Ops, Type *Ty, 1332 bool OnlyIfReduced = false, 1333 Type *SrcTy = nullptr) const; 1334 1335 /// Returns an Instruction which implements the same operation as this 1336 /// ConstantExpr. If \p InsertBefore is not null, the new instruction is 1337 /// inserted before it, otherwise it is not inserted into any basic block. 1338 /// 1339 /// A better approach to this could be to have a constructor for Instruction 1340 /// which would take a ConstantExpr parameter, but that would have spread 1341 /// implementation details of ConstantExpr outside of Constants.cpp, which 1342 /// would make it harder to remove ConstantExprs altogether. 1343 Instruction *getAsInstruction(Instruction *InsertBefore = nullptr) const; 1344 1345 /// Whether creating a constant expression for this binary operator is 1346 /// desirable. 1347 static bool isDesirableBinOp(unsigned Opcode); 1348 1349 /// Whether creating a constant expression for this binary operator is 1350 /// supported. 1351 static bool isSupportedBinOp(unsigned Opcode); 1352 1353 /// Methods for support type inquiry through isa, cast, and dyn_cast: 1354 static bool classof(const Value *V) { 1355 return V->getValueID() == ConstantExprVal; 1356 } 1357 1358 private: 1359 // Shadow Value::setValueSubclassData with a private forwarding method so that 1360 // subclasses cannot accidentally use it. 1361 void setValueSubclassData(unsigned short D) { 1362 Value::setValueSubclassData(D); 1363 } 1364 }; 1365 1366 template <> 1367 struct OperandTraits<ConstantExpr> 1368 : public VariadicOperandTraits<ConstantExpr, 1> {}; 1369 1370 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantExpr, Constant) 1371 1372 //===----------------------------------------------------------------------===// 1373 /// 'undef' values are things that do not have specified contents. 1374 /// These are used for a variety of purposes, including global variable 1375 /// initializers and operands to instructions. 'undef' values can occur with 1376 /// any first-class type. 1377 /// 1378 /// Undef values aren't exactly constants; if they have multiple uses, they 1379 /// can appear to have different bit patterns at each use. See 1380 /// LangRef.html#undefvalues for details. 1381 /// 1382 class UndefValue : public ConstantData { 1383 friend class Constant; 1384 1385 explicit UndefValue(Type *T) : ConstantData(T, UndefValueVal) {} 1386 1387 void destroyConstantImpl(); 1388 1389 protected: 1390 explicit UndefValue(Type *T, ValueTy vty) : ConstantData(T, vty) {} 1391 1392 public: 1393 UndefValue(const UndefValue &) = delete; 1394 1395 /// Static factory methods - Return an 'undef' object of the specified type. 1396 static UndefValue *get(Type *T); 1397 1398 /// If this Undef has array or vector type, return a undef with the right 1399 /// element type. 1400 UndefValue *getSequentialElement() const; 1401 1402 /// If this undef has struct type, return a undef with the right element type 1403 /// for the specified element. 1404 UndefValue *getStructElement(unsigned Elt) const; 1405 1406 /// Return an undef of the right value for the specified GEP index if we can, 1407 /// otherwise return null (e.g. if C is a ConstantExpr). 1408 UndefValue *getElementValue(Constant *C) const; 1409 1410 /// Return an undef of the right value for the specified GEP index. 1411 UndefValue *getElementValue(unsigned Idx) const; 1412 1413 /// Return the number of elements in the array, vector, or struct. 1414 unsigned getNumElements() const; 1415 1416 /// Methods for support type inquiry through isa, cast, and dyn_cast: 1417 static bool classof(const Value *V) { 1418 return V->getValueID() == UndefValueVal || 1419 V->getValueID() == PoisonValueVal; 1420 } 1421 }; 1422 1423 //===----------------------------------------------------------------------===// 1424 /// In order to facilitate speculative execution, many instructions do not 1425 /// invoke immediate undefined behavior when provided with illegal operands, 1426 /// and return a poison value instead. 1427 /// 1428 /// see LangRef.html#poisonvalues for details. 1429 /// 1430 class PoisonValue final : public UndefValue { 1431 friend class Constant; 1432 1433 explicit PoisonValue(Type *T) : UndefValue(T, PoisonValueVal) {} 1434 1435 void destroyConstantImpl(); 1436 1437 public: 1438 PoisonValue(const PoisonValue &) = delete; 1439 1440 /// Static factory methods - Return an 'poison' object of the specified type. 1441 static PoisonValue *get(Type *T); 1442 1443 /// If this poison has array or vector type, return a poison with the right 1444 /// element type. 1445 PoisonValue *getSequentialElement() const; 1446 1447 /// If this poison has struct type, return a poison with the right element 1448 /// type for the specified element. 1449 PoisonValue *getStructElement(unsigned Elt) const; 1450 1451 /// Return an poison of the right value for the specified GEP index if we can, 1452 /// otherwise return null (e.g. if C is a ConstantExpr). 1453 PoisonValue *getElementValue(Constant *C) const; 1454 1455 /// Return an poison of the right value for the specified GEP index. 1456 PoisonValue *getElementValue(unsigned Idx) const; 1457 1458 /// Methods for support type inquiry through isa, cast, and dyn_cast: 1459 static bool classof(const Value *V) { 1460 return V->getValueID() == PoisonValueVal; 1461 } 1462 }; 1463 1464 } // end namespace llvm 1465 1466 #endif // LLVM_IR_CONSTANTS_H 1467