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