LLVM  3.7.0
Constants.h
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1 //===-- llvm/Constants.h - Constant class subclass definitions --*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 /// @file
11 /// This file contains the declarations for the subclasses of Constant,
12 /// which represent the different flavors of constant values that live in LLVM.
13 /// Note that Constants are immutable (once created they never change) and are
14 /// fully shared by structural equivalence. This means that two structurally
15 /// equivalent constants will always have the same address. Constants are
16 /// created on demand as needed and never deleted: thus clients don't have to
17 /// worry about the lifetime of the objects.
18 //
19 //===----------------------------------------------------------------------===//
20 
21 #ifndef LLVM_IR_CONSTANTS_H
22 #define LLVM_IR_CONSTANTS_H
23 
24 #include "llvm/ADT/APFloat.h"
25 #include "llvm/ADT/APInt.h"
26 #include "llvm/ADT/ArrayRef.h"
27 #include "llvm/IR/Constant.h"
28 #include "llvm/IR/DerivedTypes.h"
29 #include "llvm/IR/OperandTraits.h"
30 
31 namespace llvm {
32 
33 class ArrayType;
34 class IntegerType;
35 class StructType;
36 class PointerType;
37 class VectorType;
38 class SequentialType;
39 
40 struct ConstantExprKeyType;
41 template <class ConstantClass> struct ConstantAggrKeyType;
42 
43 //===----------------------------------------------------------------------===//
44 /// This is the shared class of boolean and integer constants. This class
45 /// represents both boolean and integral constants.
46 /// @brief Class for constant integers.
47 class ConstantInt : public Constant {
48  void anchor() override;
49  void *operator new(size_t, unsigned) = delete;
50  ConstantInt(const ConstantInt &) = delete;
51  ConstantInt(IntegerType *Ty, const APInt& V);
52  APInt Val;
53 
54  friend class Constant;
55  void destroyConstantImpl();
56  Value *handleOperandChangeImpl(Value *From, Value *To, Use *U);
57 
58 protected:
59  // allocate space for exactly zero operands
60  void *operator new(size_t s) {
61  return User::operator new(s, 0);
62  }
63 public:
64  static ConstantInt *getTrue(LLVMContext &Context);
65  static ConstantInt *getFalse(LLVMContext &Context);
66  static Constant *getTrue(Type *Ty);
67  static Constant *getFalse(Type *Ty);
68 
69  /// If Ty is a vector type, return a Constant with a splat of the given
70  /// value. Otherwise return a ConstantInt for the given value.
71  static Constant *get(Type *Ty, uint64_t V, bool isSigned = false);
72 
73  /// Return a ConstantInt with the specified integer value for the specified
74  /// type. If the type is wider than 64 bits, the value will be zero-extended
75  /// to fit the type, unless isSigned is true, in which case the value will
76  /// be interpreted as a 64-bit signed integer and sign-extended to fit
77  /// the type.
78  /// @brief Get a ConstantInt for a specific value.
79  static ConstantInt *get(IntegerType *Ty, uint64_t V,
80  bool isSigned = false);
81 
82  /// Return a ConstantInt with the specified value for the specified type. The
83  /// value V will be canonicalized to a an unsigned APInt. Accessing it with
84  /// either getSExtValue() or getZExtValue() will yield a correctly sized and
85  /// signed value for the type Ty.
86  /// @brief Get a ConstantInt for a specific signed value.
87  static ConstantInt *getSigned(IntegerType *Ty, int64_t V);
88  static Constant *getSigned(Type *Ty, int64_t V);
89 
90  /// Return a ConstantInt with the specified value and an implied Type. The
91  /// type is the integer type that corresponds to the bit width of the value.
92  static ConstantInt *get(LLVMContext &Context, const APInt &V);
93 
94  /// Return a ConstantInt constructed from the string strStart with the given
95  /// radix.
96  static ConstantInt *get(IntegerType *Ty, StringRef Str,
97  uint8_t radix);
98 
99  /// If Ty is a vector type, return a Constant with a splat of the given
100  /// value. Otherwise return a ConstantInt for the given value.
101  static Constant *get(Type* Ty, const APInt& V);
102 
103  /// Return the constant as an APInt value reference. This allows clients to
104  /// obtain a copy of the value, with all its precision in tact.
105  /// @brief Return the constant's value.
106  inline const APInt &getValue() const {
107  return Val;
108  }
109 
110  /// getBitWidth - Return the bitwidth of this constant.
111  unsigned getBitWidth() const { return Val.getBitWidth(); }
112 
113  /// Return the constant as a 64-bit unsigned integer value after it
114  /// has been zero extended as appropriate for the type of this constant. Note
115  /// that this method can assert if the value does not fit in 64 bits.
116  /// @brief Return the zero extended value.
117  inline uint64_t getZExtValue() const {
118  return Val.getZExtValue();
119  }
120 
121  /// Return the constant as a 64-bit integer value after it has been sign
122  /// extended as appropriate for the type of this constant. Note that
123  /// this method can assert if the value does not fit in 64 bits.
124  /// @brief Return the sign extended value.
125  inline int64_t getSExtValue() const {
126  return Val.getSExtValue();
127  }
128 
129  /// A helper method that can be used to determine if the constant contained
130  /// within is equal to a constant. This only works for very small values,
131  /// because this is all that can be represented with all types.
132  /// @brief Determine if this constant's value is same as an unsigned char.
133  bool equalsInt(uint64_t V) const {
134  return Val == V;
135  }
136 
137  /// getType - Specialize the getType() method to always return an IntegerType,
138  /// which reduces the amount of casting needed in parts of the compiler.
139  ///
140  inline IntegerType *getType() const {
141  return cast<IntegerType>(Value::getType());
142  }
143 
144  /// This static method returns true if the type Ty is big enough to
145  /// represent the value V. This can be used to avoid having the get method
146  /// assert when V is larger than Ty can represent. Note that there are two
147  /// versions of this method, one for unsigned and one for signed integers.
148  /// Although ConstantInt canonicalizes everything to an unsigned integer,
149  /// the signed version avoids callers having to convert a signed quantity
150  /// to the appropriate unsigned type before calling the method.
151  /// @returns true if V is a valid value for type Ty
152  /// @brief Determine if the value is in range for the given type.
153  static bool isValueValidForType(Type *Ty, uint64_t V);
154  static bool isValueValidForType(Type *Ty, int64_t V);
155 
156  bool isNegative() const { return Val.isNegative(); }
157 
158  /// This is just a convenience method to make client code smaller for a
159  /// common code. It also correctly performs the comparison without the
160  /// potential for an assertion from getZExtValue().
161  bool isZero() const {
162  return Val == 0;
163  }
164 
165  /// This is just a convenience method to make client code smaller for a
166  /// common case. It also correctly performs the comparison without the
167  /// potential for an assertion from getZExtValue().
168  /// @brief Determine if the value is one.
169  bool isOne() const {
170  return Val == 1;
171  }
172 
173  /// This function will return true iff every bit in this constant is set
174  /// to true.
175  /// @returns true iff this constant's bits are all set to true.
176  /// @brief Determine if the value is all ones.
177  bool isMinusOne() const {
178  return Val.isAllOnesValue();
179  }
180 
181  /// This function will return true iff this constant represents the largest
182  /// value that may be represented by the constant's type.
183  /// @returns true iff this is the largest value that may be represented
184  /// by this type.
185  /// @brief Determine if the value is maximal.
186  bool isMaxValue(bool isSigned) const {
187  if (isSigned)
188  return Val.isMaxSignedValue();
189  else
190  return Val.isMaxValue();
191  }
192 
193  /// This function will return true iff this constant represents the smallest
194  /// value that may be represented by this constant's type.
195  /// @returns true if this is the smallest value that may be represented by
196  /// this type.
197  /// @brief Determine if the value is minimal.
198  bool isMinValue(bool isSigned) const {
199  if (isSigned)
200  return Val.isMinSignedValue();
201  else
202  return Val.isMinValue();
203  }
204 
205  /// This function will return true iff this constant represents a value with
206  /// active bits bigger than 64 bits or a value greater than the given uint64_t
207  /// value.
208  /// @returns true iff this constant is greater or equal to the given number.
209  /// @brief Determine if the value is greater or equal to the given number.
210  bool uge(uint64_t Num) const {
211  return Val.getActiveBits() > 64 || Val.getZExtValue() >= Num;
212  }
213 
214  /// getLimitedValue - If the value is smaller than the specified limit,
215  /// return it, otherwise return the limit value. This causes the value
216  /// to saturate to the limit.
217  /// @returns the min of the value of the constant and the specified value
218  /// @brief Get the constant's value with a saturation limit
219  uint64_t getLimitedValue(uint64_t Limit = ~0ULL) const {
220  return Val.getLimitedValue(Limit);
221  }
222 
223  /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
224  static bool classof(const Value *V) {
225  return V->getValueID() == ConstantIntVal;
226  }
227 };
228 
229 
230 //===----------------------------------------------------------------------===//
231 /// ConstantFP - Floating Point Values [float, double]
232 ///
233 class ConstantFP : public Constant {
234  APFloat Val;
235  void anchor() override;
236  void *operator new(size_t, unsigned) = delete;
237  ConstantFP(const ConstantFP &) = delete;
238  friend class LLVMContextImpl;
239 
240  friend class Constant;
241  void destroyConstantImpl();
242  Value *handleOperandChangeImpl(Value *From, Value *To, Use *U);
243 
244 protected:
245  ConstantFP(Type *Ty, const APFloat& V);
246 protected:
247  // allocate space for exactly zero operands
248  void *operator new(size_t s) {
249  return User::operator new(s, 0);
250  }
251 public:
252  /// Floating point negation must be implemented with f(x) = -0.0 - x. This
253  /// method returns the negative zero constant for floating point or vector
254  /// floating point types; for all other types, it returns the null value.
256 
257  /// get() - This returns a ConstantFP, or a vector containing a splat of a
258  /// ConstantFP, for the specified value in the specified type. This should
259  /// only be used for simple constant values like 2.0/1.0 etc, that are
260  /// known-valid both as host double and as the target format.
261  static Constant *get(Type* Ty, double V);
262  static Constant *get(Type* Ty, StringRef Str);
263  static ConstantFP *get(LLVMContext &Context, const APFloat &V);
264  static Constant *getNaN(Type *Ty, bool Negative = false, unsigned type = 0);
265  static Constant *getNegativeZero(Type *Ty);
266  static Constant *getInfinity(Type *Ty, bool Negative = false);
267 
268  /// isValueValidForType - return true if Ty is big enough to represent V.
269  static bool isValueValidForType(Type *Ty, const APFloat &V);
270  inline const APFloat &getValueAPF() const { return Val; }
271 
272  /// isZero - Return true if the value is positive or negative zero.
273  bool isZero() const { return Val.isZero(); }
274 
275  /// isNegative - Return true if the sign bit is set.
276  bool isNegative() const { return Val.isNegative(); }
277 
278  /// isInfinity - Return true if the value is infinity
279  bool isInfinity() const { return Val.isInfinity(); }
280 
281  /// isNaN - Return true if the value is a NaN.
282  bool isNaN() const { return Val.isNaN(); }
283 
284  /// isExactlyValue - We don't rely on operator== working on double values, as
285  /// it returns true for things that are clearly not equal, like -0.0 and 0.0.
286  /// As such, this method can be used to do an exact bit-for-bit comparison of
287  /// two floating point values. The version with a double operand is retained
288  /// because it's so convenient to write isExactlyValue(2.0), but please use
289  /// it only for simple constants.
290  bool isExactlyValue(const APFloat &V) const;
291 
292  bool isExactlyValue(double V) const {
293  bool ignored;
294  APFloat FV(V);
296  return isExactlyValue(FV);
297  }
298  /// Methods for support type inquiry through isa, cast, and dyn_cast:
299  static bool classof(const Value *V) {
300  return V->getValueID() == ConstantFPVal;
301  }
302 };
303 
304 //===----------------------------------------------------------------------===//
305 /// ConstantAggregateZero - All zero aggregate value
306 ///
308  void *operator new(size_t, unsigned) = delete;
310 
311  friend class Constant;
312  void destroyConstantImpl();
313  Value *handleOperandChangeImpl(Value *From, Value *To, Use *U);
314 
315 protected:
317  : Constant(ty, ConstantAggregateZeroVal, nullptr, 0) {}
318 protected:
319  // allocate space for exactly zero operands
320  void *operator new(size_t s) {
321  return User::operator new(s, 0);
322  }
323 public:
324  static ConstantAggregateZero *get(Type *Ty);
325 
326  /// getSequentialElement - If this CAZ has array or vector type, return a zero
327  /// with the right element type.
329 
330  /// getStructElement - If this CAZ has struct type, return a zero with the
331  /// right element type for the specified element.
332  Constant *getStructElement(unsigned Elt) const;
333 
334  /// getElementValue - Return a zero of the right value for the specified GEP
335  /// index.
337 
338  /// getElementValue - Return a zero of the right value for the specified GEP
339  /// index.
340  Constant *getElementValue(unsigned Idx) const;
341 
342  /// \brief Return the number of elements in the array, vector, or struct.
343  unsigned getNumElements() const;
344 
345  /// Methods for support type inquiry through isa, cast, and dyn_cast:
346  ///
347  static bool classof(const Value *V) {
348  return V->getValueID() == ConstantAggregateZeroVal;
349  }
350 };
351 
352 
353 //===----------------------------------------------------------------------===//
354 /// ConstantArray - Constant Array Declarations
355 ///
356 class ConstantArray : public Constant {
358  ConstantArray(const ConstantArray &) = delete;
359 
360  friend class Constant;
361  void destroyConstantImpl();
362  Value *handleOperandChangeImpl(Value *From, Value *To, Use *U);
363 
364 protected:
366 public:
367  // ConstantArray accessors
368  static Constant *get(ArrayType *T, ArrayRef<Constant*> V);
369 
370 private:
371  static Constant *getImpl(ArrayType *T, ArrayRef<Constant *> V);
372 
373 public:
374  /// Transparently provide more efficient getOperand methods.
376 
377  /// getType - Specialize the getType() method to always return an ArrayType,
378  /// which reduces the amount of casting needed in parts of the compiler.
379  ///
380  inline ArrayType *getType() const {
381  return cast<ArrayType>(Value::getType());
382  }
383 
384  /// Methods for support type inquiry through isa, cast, and dyn_cast:
385  static bool classof(const Value *V) {
386  return V->getValueID() == ConstantArrayVal;
387  }
388 };
389 
390 template <>
392  public VariadicOperandTraits<ConstantArray> {
393 };
394 
396 
397 //===----------------------------------------------------------------------===//
398 // ConstantStruct - Constant Struct Declarations
399 //
400 class ConstantStruct : public Constant {
402  ConstantStruct(const ConstantStruct &) = delete;
403 
404  friend class Constant;
405  void destroyConstantImpl();
406  Value *handleOperandChangeImpl(Value *From, Value *To, Use *U);
407 
408 protected:
410 public:
411  // ConstantStruct accessors
412  static Constant *get(StructType *T, ArrayRef<Constant*> V);
413  static Constant *get(StructType *T, ...) LLVM_END_WITH_NULL;
414 
415  /// getAnon - Return an anonymous struct that has the specified
416  /// elements. If the struct is possibly empty, then you must specify a
417  /// context.
418  static Constant *getAnon(ArrayRef<Constant*> V, bool Packed = false) {
419  return get(getTypeForElements(V, Packed), V);
420  }
422  ArrayRef<Constant*> V, bool Packed = false) {
423  return get(getTypeForElements(Ctx, V, Packed), V);
424  }
425 
426  /// getTypeForElements - Return an anonymous struct type to use for a constant
427  /// with the specified set of elements. The list must not be empty.
428  static StructType *getTypeForElements(ArrayRef<Constant*> V,
429  bool Packed = false);
430  /// getTypeForElements - This version of the method allows an empty list.
431  static StructType *getTypeForElements(LLVMContext &Ctx,
433  bool Packed = false);
434 
435  /// Transparently provide more efficient getOperand methods.
437 
438  /// getType() specialization - Reduce amount of casting...
439  ///
440  inline StructType *getType() const {
441  return cast<StructType>(Value::getType());
442  }
443 
444  /// Methods for support type inquiry through isa, cast, and dyn_cast:
445  static bool classof(const Value *V) {
446  return V->getValueID() == ConstantStructVal;
447  }
448 };
449 
450 template <>
452  public VariadicOperandTraits<ConstantStruct> {
453 };
454 
456 
457 
458 //===----------------------------------------------------------------------===//
459 /// ConstantVector - Constant Vector Declarations
460 ///
461 class ConstantVector : public Constant {
463  ConstantVector(const ConstantVector &) = delete;
464 
465  friend class Constant;
466  void destroyConstantImpl();
467  Value *handleOperandChangeImpl(Value *From, Value *To, Use *U);
468 
469 protected:
471 public:
472  // ConstantVector accessors
473  static Constant *get(ArrayRef<Constant*> V);
474 
475 private:
476  static Constant *getImpl(ArrayRef<Constant *> V);
477 
478 public:
479  /// getSplat - Return a ConstantVector with the specified constant in each
480  /// element.
481  static Constant *getSplat(unsigned NumElts, Constant *Elt);
482 
483  /// Transparently provide more efficient getOperand methods.
485 
486  /// getType - Specialize the getType() method to always return a VectorType,
487  /// which reduces the amount of casting needed in parts of the compiler.
488  ///
489  inline VectorType *getType() const {
490  return cast<VectorType>(Value::getType());
491  }
492 
493  /// getSplatValue - If this is a splat constant, meaning that all of the
494  /// elements have the same value, return that value. Otherwise return NULL.
495  Constant *getSplatValue() const;
496 
497  /// Methods for support type inquiry through isa, cast, and dyn_cast:
498  static bool classof(const Value *V) {
499  return V->getValueID() == ConstantVectorVal;
500  }
501 };
502 
503 template <>
505  public VariadicOperandTraits<ConstantVector> {
506 };
507 
509 
510 //===----------------------------------------------------------------------===//
511 /// ConstantPointerNull - a constant pointer value that points to null
512 ///
514  void *operator new(size_t, unsigned) = delete;
515  ConstantPointerNull(const ConstantPointerNull &) = delete;
516 
517  friend class Constant;
518  void destroyConstantImpl();
519  Value *handleOperandChangeImpl(Value *From, Value *To, Use *U);
520 
521 protected:
523  : Constant(T,
524  Value::ConstantPointerNullVal, nullptr, 0) {}
525 
526 protected:
527  // allocate space for exactly zero operands
528  void *operator new(size_t s) {
529  return User::operator new(s, 0);
530  }
531 public:
532  /// get() - Static factory methods - Return objects of the specified value
533  static ConstantPointerNull *get(PointerType *T);
534 
535  /// getType - Specialize the getType() method to always return an PointerType,
536  /// which reduces the amount of casting needed in parts of the compiler.
537  ///
538  inline PointerType *getType() const {
539  return cast<PointerType>(Value::getType());
540  }
541 
542  /// Methods for support type inquiry through isa, cast, and dyn_cast:
543  static bool classof(const Value *V) {
544  return V->getValueID() == ConstantPointerNullVal;
545  }
546 };
547 
548 //===----------------------------------------------------------------------===//
549 /// ConstantDataSequential - A vector or array constant whose element type is a
550 /// simple 1/2/4/8-byte integer or float/double, and whose elements are just
551 /// simple data values (i.e. ConstantInt/ConstantFP). This Constant node has no
552 /// operands because it stores all of the elements of the constant as densely
553 /// packed data, instead of as Value*'s.
554 ///
555 /// This is the common base class of ConstantDataArray and ConstantDataVector.
556 ///
558  friend class LLVMContextImpl;
559  /// DataElements - A pointer to the bytes underlying this constant (which is
560  /// owned by the uniquing StringMap).
561  const char *DataElements;
562 
563  /// Next - This forms a link list of ConstantDataSequential nodes that have
564  /// the same value but different type. For example, 0,0,0,1 could be a 4
565  /// element array of i8, or a 1-element array of i32. They'll both end up in
566  /// the same StringMap bucket, linked up.
568  void *operator new(size_t, unsigned) = delete;
570 
571  friend class Constant;
572  void destroyConstantImpl();
573  Value *handleOperandChangeImpl(Value *From, Value *To, Use *U);
574 
575 protected:
576  explicit ConstantDataSequential(Type *ty, ValueTy VT, const char *Data)
577  : Constant(ty, VT, nullptr, 0), DataElements(Data), Next(nullptr) {}
578  ~ConstantDataSequential() override { delete Next; }
579 
580  static Constant *getImpl(StringRef Bytes, Type *Ty);
581 
582 protected:
583  // allocate space for exactly zero operands.
584  void *operator new(size_t s) {
585  return User::operator new(s, 0);
586  }
587 public:
588 
589  /// isElementTypeCompatible - Return true if a ConstantDataSequential can be
590  /// formed with a vector or array of the specified element type.
591  /// ConstantDataArray only works with normal float and int types that are
592  /// stored densely in memory, not with things like i42 or x86_f80.
593  static bool isElementTypeCompatible(const Type *Ty);
594 
595  /// getElementAsInteger - If this is a sequential container of integers (of
596  /// any size), return the specified element in the low bits of a uint64_t.
597  uint64_t getElementAsInteger(unsigned i) const;
598 
599  /// getElementAsAPFloat - If this is a sequential container of floating point
600  /// type, return the specified element as an APFloat.
601  APFloat getElementAsAPFloat(unsigned i) const;
602 
603  /// getElementAsFloat - If this is an sequential container of floats, return
604  /// the specified element as a float.
605  float getElementAsFloat(unsigned i) const;
606 
607  /// getElementAsDouble - If this is an sequential container of doubles, return
608  /// the specified element as a double.
609  double getElementAsDouble(unsigned i) const;
610 
611  /// getElementAsConstant - Return a Constant for a specified index's element.
612  /// Note that this has to compute a new constant to return, so it isn't as
613  /// efficient as getElementAsInteger/Float/Double.
614  Constant *getElementAsConstant(unsigned i) const;
615 
616  /// getType - Specialize the getType() method to always return a
617  /// SequentialType, which reduces the amount of casting needed in parts of the
618  /// compiler.
619  inline SequentialType *getType() const {
620  return cast<SequentialType>(Value::getType());
621  }
622 
623  /// getElementType - Return the element type of the array/vector.
624  Type *getElementType() const;
625 
626  /// getNumElements - Return the number of elements in the array or vector.
627  unsigned getNumElements() const;
628 
629  /// getElementByteSize - Return the size (in bytes) of each element in the
630  /// array/vector. The size of the elements is known to be a multiple of one
631  /// byte.
632  uint64_t getElementByteSize() const;
633 
634 
635  /// isString - This method returns true if this is an array of i8.
636  bool isString() const;
637 
638  /// isCString - This method returns true if the array "isString", ends with a
639  /// nul byte, and does not contains any other nul bytes.
640  bool isCString() const;
641 
642  /// getAsString - If this array is isString(), then this method returns the
643  /// array as a StringRef. Otherwise, it asserts out.
644  ///
646  assert(isString() && "Not a string");
647  return getRawDataValues();
648  }
649 
650  /// getAsCString - If this array is isCString(), then this method returns the
651  /// array (without the trailing null byte) as a StringRef. Otherwise, it
652  /// asserts out.
653  ///
655  assert(isCString() && "Isn't a C string");
656  StringRef Str = getAsString();
657  return Str.substr(0, Str.size()-1);
658  }
659 
660  /// getRawDataValues - Return the raw, underlying, bytes of this data. Note
661  /// that this is an extremely tricky thing to work with, as it exposes the
662  /// host endianness of the data elements.
663  StringRef getRawDataValues() const;
664 
665  /// Methods for support type inquiry through isa, cast, and dyn_cast:
666  ///
667  static bool classof(const Value *V) {
668  return V->getValueID() == ConstantDataArrayVal ||
669  V->getValueID() == ConstantDataVectorVal;
670  }
671 private:
672  const char *getElementPointer(unsigned Elt) const;
673 };
674 
675 //===----------------------------------------------------------------------===//
676 /// ConstantDataArray - An array constant whose element type is a simple
677 /// 1/2/4/8-byte integer or float/double, and whose elements are just simple
678 /// data values (i.e. ConstantInt/ConstantFP). This Constant node has no
679 /// operands because it stores all of the elements of the constant as densely
680 /// packed data, instead of as Value*'s.
682  void *operator new(size_t, unsigned) = delete;
683  ConstantDataArray(const ConstantDataArray &) = delete;
684  void anchor() override;
686  explicit ConstantDataArray(Type *ty, const char *Data)
687  : ConstantDataSequential(ty, ConstantDataArrayVal, Data) {}
688 protected:
689  // allocate space for exactly zero operands.
690  void *operator new(size_t s) {
691  return User::operator new(s, 0);
692  }
693 public:
694 
695  /// get() constructors - Return a constant with array type with an element
696  /// count and element type matching the ArrayRef passed in. Note that this
697  /// can return a ConstantAggregateZero object.
698  static Constant *get(LLVMContext &Context, ArrayRef<uint8_t> Elts);
699  static Constant *get(LLVMContext &Context, ArrayRef<uint16_t> Elts);
700  static Constant *get(LLVMContext &Context, ArrayRef<uint32_t> Elts);
701  static Constant *get(LLVMContext &Context, ArrayRef<uint64_t> Elts);
702  static Constant *get(LLVMContext &Context, ArrayRef<float> Elts);
703  static Constant *get(LLVMContext &Context, ArrayRef<double> Elts);
704 
705  /// getFP() constructors - Return a constant with array type with an element
706  /// count and element type of float with precision matching the number of
707  /// bits in the ArrayRef passed in. (i.e. half for 16bits, float for 32bits,
708  /// double for 64bits) Note that this can return a ConstantAggregateZero
709  /// object.
710  static Constant *getFP(LLVMContext &Context, ArrayRef<uint16_t> Elts);
711  static Constant *getFP(LLVMContext &Context, ArrayRef<uint32_t> Elts);
712  static Constant *getFP(LLVMContext &Context, ArrayRef<uint64_t> Elts);
713 
714  /// getString - This method constructs a CDS and initializes it with a text
715  /// string. The default behavior (AddNull==true) causes a null terminator to
716  /// be placed at the end of the array (increasing the length of the string by
717  /// one more than the StringRef would normally indicate. Pass AddNull=false
718  /// to disable this behavior.
719  static Constant *getString(LLVMContext &Context, StringRef Initializer,
720  bool AddNull = true);
721 
722  /// getType - Specialize the getType() method to always return an ArrayType,
723  /// which reduces the amount of casting needed in parts of the compiler.
724  ///
725  inline ArrayType *getType() const {
726  return cast<ArrayType>(Value::getType());
727  }
728 
729  /// Methods for support type inquiry through isa, cast, and dyn_cast:
730  ///
731  static bool classof(const Value *V) {
732  return V->getValueID() == ConstantDataArrayVal;
733  }
734 };
735 
736 //===----------------------------------------------------------------------===//
737 /// ConstantDataVector - A vector constant whose element type is a simple
738 /// 1/2/4/8-byte integer or float/double, and whose elements are just simple
739 /// data values (i.e. ConstantInt/ConstantFP). This Constant node has no
740 /// operands because it stores all of the elements of the constant as densely
741 /// packed data, instead of as Value*'s.
743  void *operator new(size_t, unsigned) = delete;
744  ConstantDataVector(const ConstantDataVector &) = delete;
745  void anchor() override;
747  explicit ConstantDataVector(Type *ty, const char *Data)
748  : ConstantDataSequential(ty, ConstantDataVectorVal, Data) {}
749 protected:
750  // allocate space for exactly zero operands.
751  void *operator new(size_t s) {
752  return User::operator new(s, 0);
753  }
754 public:
755 
756  /// get() constructors - Return a constant with vector type with an element
757  /// count and element type matching the ArrayRef passed in. Note that this
758  /// can return a ConstantAggregateZero object.
759  static Constant *get(LLVMContext &Context, ArrayRef<uint8_t> Elts);
760  static Constant *get(LLVMContext &Context, ArrayRef<uint16_t> Elts);
761  static Constant *get(LLVMContext &Context, ArrayRef<uint32_t> Elts);
762  static Constant *get(LLVMContext &Context, ArrayRef<uint64_t> Elts);
763  static Constant *get(LLVMContext &Context, ArrayRef<float> Elts);
764  static Constant *get(LLVMContext &Context, ArrayRef<double> Elts);
765 
766  /// getFP() constructors - Return a constant with vector type with an element
767  /// count and element type of float with the precision matching the number of
768  /// bits in the ArrayRef passed in. (i.e. half for 16bits, float for 32bits,
769  /// double for 64bits) Note that this can return a ConstantAggregateZero
770  /// object.
771  static Constant *getFP(LLVMContext &Context, ArrayRef<uint16_t> Elts);
772  static Constant *getFP(LLVMContext &Context, ArrayRef<uint32_t> Elts);
773  static Constant *getFP(LLVMContext &Context, ArrayRef<uint64_t> Elts);
774 
775  /// getSplat - Return a ConstantVector with the specified constant in each
776  /// element. The specified constant has to be a of a compatible type (i8/i16/
777  /// i32/i64/float/double) and must be a ConstantFP or ConstantInt.
778  static Constant *getSplat(unsigned NumElts, Constant *Elt);
779 
780  /// getSplatValue - If this is a splat constant, meaning that all of the
781  /// elements have the same value, return that value. Otherwise return NULL.
782  Constant *getSplatValue() const;
783 
784  /// getType - Specialize the getType() method to always return a VectorType,
785  /// which reduces the amount of casting needed in parts of the compiler.
786  ///
787  inline VectorType *getType() const {
788  return cast<VectorType>(Value::getType());
789  }
790 
791  /// Methods for support type inquiry through isa, cast, and dyn_cast:
792  ///
793  static bool classof(const Value *V) {
794  return V->getValueID() == ConstantDataVectorVal;
795  }
796 };
797 
798 
799 
800 /// BlockAddress - The address of a basic block.
801 ///
802 class BlockAddress : public Constant {
803  void *operator new(size_t, unsigned) = delete;
804  void *operator new(size_t s) { return User::operator new(s, 2); }
806 
807  friend class Constant;
808  void destroyConstantImpl();
809  Value *handleOperandChangeImpl(Value *From, Value *To, Use *U);
810 
811 public:
812  /// get - Return a BlockAddress for the specified function and basic block.
813  static BlockAddress *get(Function *F, BasicBlock *BB);
814 
815  /// get - Return a BlockAddress for the specified basic block. The basic
816  /// block must be embedded into a function.
817  static BlockAddress *get(BasicBlock *BB);
818 
819  /// \brief Lookup an existing \c BlockAddress constant for the given
820  /// BasicBlock.
821  ///
822  /// \returns 0 if \c !BB->hasAddressTaken(), otherwise the \c BlockAddress.
823  static BlockAddress *lookup(const BasicBlock *BB);
824 
825  /// Transparently provide more efficient getOperand methods.
827 
828  Function *getFunction() const { return (Function*)Op<0>().get(); }
829  BasicBlock *getBasicBlock() const { return (BasicBlock*)Op<1>().get(); }
830 
831  /// Methods for support type inquiry through isa, cast, and dyn_cast:
832  static inline bool classof(const Value *V) {
833  return V->getValueID() == BlockAddressVal;
834  }
835 };
836 
837 template <>
839  public FixedNumOperandTraits<BlockAddress, 2> {
840 };
841 
843 
844 
845 //===----------------------------------------------------------------------===//
846 /// ConstantExpr - a constant value that is initialized with an expression using
847 /// other constant values.
848 ///
849 /// This class uses the standard Instruction opcodes to define the various
850 /// constant expressions. The Opcode field for the ConstantExpr class is
851 /// maintained in the Value::SubclassData field.
852 class ConstantExpr : public Constant {
853  friend struct ConstantExprKeyType;
854 
855  friend class Constant;
856  void destroyConstantImpl();
857  Value *handleOperandChangeImpl(Value *From, Value *To, Use *U);
858 
859 protected:
860  ConstantExpr(Type *ty, unsigned Opcode, Use *Ops, unsigned NumOps)
861  : Constant(ty, ConstantExprVal, Ops, NumOps) {
862  // Operation type (an Instruction opcode) is stored as the SubclassData.
863  setValueSubclassData(Opcode);
864  }
865 
866 public:
867  // Static methods to construct a ConstantExpr of different kinds. Note that
868  // these methods may return a object that is not an instance of the
869  // ConstantExpr class, because they will attempt to fold the constant
870  // expression into something simpler if possible.
871 
872  /// getAlignOf constant expr - computes the alignment of a type in a target
873  /// independent way (Note: the return type is an i64).
874  static Constant *getAlignOf(Type *Ty);
875 
876  /// getSizeOf constant expr - computes the (alloc) size of a type (in
877  /// address-units, not bits) in a target independent way (Note: the return
878  /// type is an i64).
879  ///
880  static Constant *getSizeOf(Type *Ty);
881 
882  /// getOffsetOf constant expr - computes the offset of a struct field in a
883  /// target independent way (Note: the return type is an i64).
884  ///
885  static Constant *getOffsetOf(StructType *STy, unsigned FieldNo);
886 
887  /// getOffsetOf constant expr - This is a generalized form of getOffsetOf,
888  /// which supports any aggregate type, and any Constant index.
889  ///
890  static Constant *getOffsetOf(Type *Ty, Constant *FieldNo);
891 
892  static Constant *getNeg(Constant *C, bool HasNUW = false, bool HasNSW =false);
893  static Constant *getFNeg(Constant *C);
894  static Constant *getNot(Constant *C);
895  static Constant *getAdd(Constant *C1, Constant *C2,
896  bool HasNUW = false, bool HasNSW = false);
897  static Constant *getFAdd(Constant *C1, Constant *C2);
898  static Constant *getSub(Constant *C1, Constant *C2,
899  bool HasNUW = false, bool HasNSW = false);
900  static Constant *getFSub(Constant *C1, Constant *C2);
901  static Constant *getMul(Constant *C1, Constant *C2,
902  bool HasNUW = false, bool HasNSW = false);
903  static Constant *getFMul(Constant *C1, Constant *C2);
904  static Constant *getUDiv(Constant *C1, Constant *C2, bool isExact = false);
905  static Constant *getSDiv(Constant *C1, Constant *C2, bool isExact = false);
906  static Constant *getFDiv(Constant *C1, Constant *C2);
907  static Constant *getURem(Constant *C1, Constant *C2);
908  static Constant *getSRem(Constant *C1, Constant *C2);
909  static Constant *getFRem(Constant *C1, Constant *C2);
910  static Constant *getAnd(Constant *C1, Constant *C2);
911  static Constant *getOr(Constant *C1, Constant *C2);
912  static Constant *getXor(Constant *C1, Constant *C2);
913  static Constant *getShl(Constant *C1, Constant *C2,
914  bool HasNUW = false, bool HasNSW = false);
915  static Constant *getLShr(Constant *C1, Constant *C2, bool isExact = false);
916  static Constant *getAShr(Constant *C1, Constant *C2, bool isExact = false);
917  static Constant *getTrunc(Constant *C, Type *Ty, bool OnlyIfReduced = false);
918  static Constant *getSExt(Constant *C, Type *Ty, bool OnlyIfReduced = false);
919  static Constant *getZExt(Constant *C, Type *Ty, bool OnlyIfReduced = false);
920  static Constant *getFPTrunc(Constant *C, Type *Ty,
921  bool OnlyIfReduced = false);
922  static Constant *getFPExtend(Constant *C, Type *Ty,
923  bool OnlyIfReduced = false);
924  static Constant *getUIToFP(Constant *C, Type *Ty, bool OnlyIfReduced = false);
925  static Constant *getSIToFP(Constant *C, Type *Ty, bool OnlyIfReduced = false);
926  static Constant *getFPToUI(Constant *C, Type *Ty, bool OnlyIfReduced = false);
927  static Constant *getFPToSI(Constant *C, Type *Ty, bool OnlyIfReduced = false);
928  static Constant *getPtrToInt(Constant *C, Type *Ty,
929  bool OnlyIfReduced = false);
930  static Constant *getIntToPtr(Constant *C, Type *Ty,
931  bool OnlyIfReduced = false);
932  static Constant *getBitCast(Constant *C, Type *Ty,
933  bool OnlyIfReduced = false);
934  static Constant *getAddrSpaceCast(Constant *C, Type *Ty,
935  bool OnlyIfReduced = false);
936 
937  static Constant *getNSWNeg(Constant *C) { return getNeg(C, false, true); }
938  static Constant *getNUWNeg(Constant *C) { return getNeg(C, true, false); }
939  static Constant *getNSWAdd(Constant *C1, Constant *C2) {
940  return getAdd(C1, C2, false, true);
941  }
942  static Constant *getNUWAdd(Constant *C1, Constant *C2) {
943  return getAdd(C1, C2, true, false);
944  }
945  static Constant *getNSWSub(Constant *C1, Constant *C2) {
946  return getSub(C1, C2, false, true);
947  }
948  static Constant *getNUWSub(Constant *C1, Constant *C2) {
949  return getSub(C1, C2, true, false);
950  }
951  static Constant *getNSWMul(Constant *C1, Constant *C2) {
952  return getMul(C1, C2, false, true);
953  }
954  static Constant *getNUWMul(Constant *C1, Constant *C2) {
955  return getMul(C1, C2, true, false);
956  }
957  static Constant *getNSWShl(Constant *C1, Constant *C2) {
958  return getShl(C1, C2, false, true);
959  }
960  static Constant *getNUWShl(Constant *C1, Constant *C2) {
961  return getShl(C1, C2, true, false);
962  }
963  static Constant *getExactSDiv(Constant *C1, Constant *C2) {
964  return getSDiv(C1, C2, true);
965  }
966  static Constant *getExactUDiv(Constant *C1, Constant *C2) {
967  return getUDiv(C1, C2, true);
968  }
969  static Constant *getExactAShr(Constant *C1, Constant *C2) {
970  return getAShr(C1, C2, true);
971  }
972  static Constant *getExactLShr(Constant *C1, Constant *C2) {
973  return getLShr(C1, C2, true);
974  }
975 
976  /// getBinOpIdentity - Return the identity for the given binary operation,
977  /// i.e. a constant C such that X op C = X and C op X = X for every X. It
978  /// returns null if the operator doesn't have an identity.
979  static Constant *getBinOpIdentity(unsigned Opcode, Type *Ty);
980 
981  /// getBinOpAbsorber - Return the absorbing element for the given binary
982  /// operation, i.e. a constant C such that X op C = C and C op X = C for
983  /// every X. For example, this returns zero for integer multiplication.
984  /// It returns null if the operator doesn't have an absorbing element.
985  static Constant *getBinOpAbsorber(unsigned Opcode, Type *Ty);
986 
987  /// Transparently provide more efficient getOperand methods.
989 
990  /// \brief Convenience function for getting a Cast operation.
991  ///
992  /// \param ops The opcode for the conversion
993  /// \param C The constant to be converted
994  /// \param Ty The type to which the constant is converted
995  /// \param OnlyIfReduced see \a getWithOperands() docs.
996  static Constant *getCast(unsigned ops, Constant *C, Type *Ty,
997  bool OnlyIfReduced = false);
998 
999  // @brief Create a ZExt or BitCast cast constant expression
1000  static Constant *getZExtOrBitCast(
1001  Constant *C, ///< The constant to zext or bitcast
1002  Type *Ty ///< The type to zext or bitcast C to
1003  );
1004 
1005  // @brief Create a SExt or BitCast cast constant expression
1006  static Constant *getSExtOrBitCast(
1007  Constant *C, ///< The constant to sext or bitcast
1008  Type *Ty ///< The type to sext or bitcast C to
1009  );
1010 
1011  // @brief Create a Trunc or BitCast cast constant expression
1012  static Constant *getTruncOrBitCast(
1013  Constant *C, ///< The constant to trunc or bitcast
1014  Type *Ty ///< The type to trunc or bitcast C to
1015  );
1016 
1017  /// @brief Create a BitCast, AddrSpaceCast, or a PtrToInt cast constant
1018  /// expression.
1019  static Constant *getPointerCast(
1020  Constant *C, ///< The pointer value to be casted (operand 0)
1021  Type *Ty ///< The type to which cast should be made
1022  );
1023 
1024  /// @brief Create a BitCast or AddrSpaceCast for a pointer type depending on
1025  /// the address space.
1026  static Constant *getPointerBitCastOrAddrSpaceCast(
1027  Constant *C, ///< The constant to addrspacecast or bitcast
1028  Type *Ty ///< The type to bitcast or addrspacecast C to
1029  );
1030 
1031  /// @brief Create a ZExt, Bitcast or Trunc for integer -> integer casts
1032  static Constant *getIntegerCast(
1033  Constant *C, ///< The integer constant to be casted
1034  Type *Ty, ///< The integer type to cast to
1035  bool isSigned ///< Whether C should be treated as signed or not
1036  );
1037 
1038  /// @brief Create a FPExt, Bitcast or FPTrunc for fp -> fp casts
1039  static Constant *getFPCast(
1040  Constant *C, ///< The integer constant to be casted
1041  Type *Ty ///< The integer type to cast to
1042  );
1043 
1044  /// @brief Return true if this is a convert constant expression
1045  bool isCast() const;
1046 
1047  /// @brief Return true if this is a compare constant expression
1048  bool isCompare() const;
1049 
1050  /// @brief Return true if this is an insertvalue or extractvalue expression,
1051  /// and the getIndices() method may be used.
1052  bool hasIndices() const;
1053 
1054  /// @brief Return true if this is a getelementptr expression and all
1055  /// the index operands are compile-time known integers within the
1056  /// corresponding notional static array extents. Note that this is
1057  /// not equivalant to, a subset of, or a superset of the "inbounds"
1058  /// property.
1059  bool isGEPWithNoNotionalOverIndexing() const;
1060 
1061  /// Select constant expr
1062  ///
1063  /// \param OnlyIfReducedTy see \a getWithOperands() docs.
1064  static Constant *getSelect(Constant *C, Constant *V1, Constant *V2,
1065  Type *OnlyIfReducedTy = nullptr);
1066 
1067  /// get - Return a binary or shift operator constant expression,
1068  /// folding if possible.
1069  ///
1070  /// \param OnlyIfReducedTy see \a getWithOperands() docs.
1071  static Constant *get(unsigned Opcode, Constant *C1, Constant *C2,
1072  unsigned Flags = 0, Type *OnlyIfReducedTy = nullptr);
1073 
1074  /// \brief Return an ICmp or FCmp comparison operator constant expression.
1075  ///
1076  /// \param OnlyIfReduced see \a getWithOperands() docs.
1077  static Constant *getCompare(unsigned short pred, Constant *C1, Constant *C2,
1078  bool OnlyIfReduced = false);
1079 
1080  /// get* - Return some common constants without having to
1081  /// specify the full Instruction::OPCODE identifier.
1082  ///
1083  static Constant *getICmp(unsigned short pred, Constant *LHS, Constant *RHS,
1084  bool OnlyIfReduced = false);
1085  static Constant *getFCmp(unsigned short pred, Constant *LHS, Constant *RHS,
1086  bool OnlyIfReduced = false);
1087 
1088  /// Getelementptr form. Value* is only accepted for convenience;
1089  /// all elements must be Constants.
1090  ///
1091  /// \param OnlyIfReducedTy see \a getWithOperands() docs.
1092  static Constant *getGetElementPtr(Type *Ty, Constant *C,
1093  ArrayRef<Constant *> IdxList,
1094  bool InBounds = false,
1095  Type *OnlyIfReducedTy = nullptr) {
1096  return getGetElementPtr(
1097  Ty, C, makeArrayRef((Value * const *)IdxList.data(), IdxList.size()),
1098  InBounds, OnlyIfReducedTy);
1099  }
1100  static Constant *getGetElementPtr(Type *Ty, Constant *C, Constant *Idx,
1101  bool InBounds = false,
1102  Type *OnlyIfReducedTy = nullptr) {
1103  // This form of the function only exists to avoid ambiguous overload
1104  // warnings about whether to convert Idx to ArrayRef<Constant *> or
1105  // ArrayRef<Value *>.
1106  return getGetElementPtr(Ty, C, cast<Value>(Idx), InBounds, OnlyIfReducedTy);
1107  }
1108  static Constant *getGetElementPtr(Type *Ty, Constant *C,
1109  ArrayRef<Value *> IdxList,
1110  bool InBounds = false,
1111  Type *OnlyIfReducedTy = nullptr);
1112 
1113  /// Create an "inbounds" getelementptr. See the documentation for the
1114  /// "inbounds" flag in LangRef.html for details.
1115  static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C,
1116  ArrayRef<Constant *> IdxList) {
1117  return getGetElementPtr(Ty, C, IdxList, true);
1118  }
1119  static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C,
1120  Constant *Idx) {
1121  // This form of the function only exists to avoid ambiguous overload
1122  // warnings about whether to convert Idx to ArrayRef<Constant *> or
1123  // ArrayRef<Value *>.
1124  return getGetElementPtr(Ty, C, Idx, true);
1125  }
1126  static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C,
1127  ArrayRef<Value *> IdxList) {
1128  return getGetElementPtr(Ty, C, IdxList, true);
1129  }
1130 
1131  static Constant *getExtractElement(Constant *Vec, Constant *Idx,
1132  Type *OnlyIfReducedTy = nullptr);
1133  static Constant *getInsertElement(Constant *Vec, Constant *Elt, Constant *Idx,
1134  Type *OnlyIfReducedTy = nullptr);
1135  static Constant *getShuffleVector(Constant *V1, Constant *V2, Constant *Mask,
1136  Type *OnlyIfReducedTy = nullptr);
1137  static Constant *getExtractValue(Constant *Agg, ArrayRef<unsigned> Idxs,
1138  Type *OnlyIfReducedTy = nullptr);
1139  static Constant *getInsertValue(Constant *Agg, Constant *Val,
1140  ArrayRef<unsigned> Idxs,
1141  Type *OnlyIfReducedTy = nullptr);
1142 
1143  /// getOpcode - Return the opcode at the root of this constant expression
1144  unsigned getOpcode() const { return getSubclassDataFromValue(); }
1145 
1146  /// getPredicate - Return the ICMP or FCMP predicate value. Assert if this is
1147  /// not an ICMP or FCMP constant expression.
1148  unsigned getPredicate() const;
1149 
1150  /// getIndices - Assert that this is an insertvalue or exactvalue
1151  /// expression and return the list of indices.
1152  ArrayRef<unsigned> getIndices() const;
1153 
1154  /// getOpcodeName - Return a string representation for an opcode.
1155  const char *getOpcodeName() const;
1156 
1157  /// getWithOperandReplaced - Return a constant expression identical to this
1158  /// one, but with the specified operand set to the specified value.
1159  Constant *getWithOperandReplaced(unsigned OpNo, Constant *Op) const;
1160 
1161  /// getWithOperands - This returns the current constant expression with the
1162  /// operands replaced with the specified values. The specified array must
1163  /// have the same number of operands as our current one.
1164  Constant *getWithOperands(ArrayRef<Constant*> Ops) const {
1165  return getWithOperands(Ops, getType());
1166  }
1167 
1168  /// \brief Get the current expression with the operands replaced.
1169  ///
1170  /// Return the current constant expression with the operands replaced with \c
1171  /// Ops and the type with \c Ty. The new operands must have the same number
1172  /// as the current ones.
1173  ///
1174  /// If \c OnlyIfReduced is \c true, nullptr will be returned unless something
1175  /// gets constant-folded, the type changes, or the expression is otherwise
1176  /// canonicalized. This parameter should almost always be \c false.
1177  Constant *getWithOperands(ArrayRef<Constant *> Ops, Type *Ty,
1178  bool OnlyIfReduced = false) const;
1179 
1180  /// getAsInstruction - Returns an Instruction which implements the same
1181  /// operation as this ConstantExpr. The instruction is not linked to any basic
1182  /// block.
1183  ///
1184  /// A better approach to this could be to have a constructor for Instruction
1185  /// which would take a ConstantExpr parameter, but that would have spread
1186  /// implementation details of ConstantExpr outside of Constants.cpp, which
1187  /// would make it harder to remove ConstantExprs altogether.
1188  Instruction *getAsInstruction();
1189 
1190  /// Methods for support type inquiry through isa, cast, and dyn_cast:
1191  static inline bool classof(const Value *V) {
1192  return V->getValueID() == ConstantExprVal;
1193  }
1194 
1195 private:
1196  // Shadow Value::setValueSubclassData with a private forwarding method so that
1197  // subclasses cannot accidentally use it.
1198  void setValueSubclassData(unsigned short D) {
1200  }
1201 };
1202 
1203 template <>
1205  public VariadicOperandTraits<ConstantExpr, 1> {
1206 };
1207 
1209 
1210 //===----------------------------------------------------------------------===//
1211 /// UndefValue - 'undef' values are things that do not have specified contents.
1212 /// These are used for a variety of purposes, including global variable
1213 /// initializers and operands to instructions. 'undef' values can occur with
1214 /// any first-class type.
1215 ///
1216 /// Undef values aren't exactly constants; if they have multiple uses, they
1217 /// can appear to have different bit patterns at each use. See
1218 /// LangRef.html#undefvalues for details.
1219 ///
1220 class UndefValue : public Constant {
1221  void *operator new(size_t, unsigned) = delete;
1222  UndefValue(const UndefValue &) = delete;
1223 
1224  friend class Constant;
1225  void destroyConstantImpl();
1226  Value *handleOperandChangeImpl(Value *From, Value *To, Use *U);
1227 
1228 protected:
1229  explicit UndefValue(Type *T) : Constant(T, UndefValueVal, nullptr, 0) {}
1230 protected:
1231  // allocate space for exactly zero operands
1232  void *operator new(size_t s) {
1233  return User::operator new(s, 0);
1234  }
1235 public:
1236  /// get() - Static factory methods - Return an 'undef' object of the specified
1237  /// type.
1238  ///
1239  static UndefValue *get(Type *T);
1240 
1241  /// getSequentialElement - If this Undef has array or vector type, return a
1242  /// undef with the right element type.
1243  UndefValue *getSequentialElement() const;
1244 
1245  /// getStructElement - If this undef has struct type, return a undef with the
1246  /// right element type for the specified element.
1247  UndefValue *getStructElement(unsigned Elt) const;
1248 
1249  /// getElementValue - Return an undef of the right value for the specified GEP
1250  /// index.
1251  UndefValue *getElementValue(Constant *C) const;
1252 
1253  /// getElementValue - Return an undef of the right value for the specified GEP
1254  /// index.
1255  UndefValue *getElementValue(unsigned Idx) const;
1256 
1257  /// \brief Return the number of elements in the array, vector, or struct.
1258  unsigned getNumElements() const;
1259 
1260  /// Methods for support type inquiry through isa, cast, and dyn_cast:
1261  static bool classof(const Value *V) {
1262  return V->getValueID() == UndefValueVal;
1263  }
1264 };
1265 
1266 } // End llvm namespace
1267 
1268 #endif
static bool isValueValidForType(Type *Ty, uint64_t V)
This static method returns true if the type Ty is big enough to represent the value V...
Definition: Constants.cpp:1305
ConstantDataVector - A vector constant whose element type is a simple 1/2/4/8-byte integer or float/d...
Definition: Constants.h:742
static ConstantInt * getFalse(LLVMContext &Context)
Definition: Constants.cpp:537
IntegerType * getType() const
getType - Specialize the getType() method to always return an IntegerType, which reduces the amount o...
Definition: Constants.h:140
static Constant * getString(LLVMContext &Context, StringRef Initializer, bool AddNull=true)
getString - This method constructs a CDS and initializes it with a text string.
Definition: Constants.cpp:2612
APFloat getElementAsAPFloat(unsigned i) const
getElementAsAPFloat - If this is a sequential container of floating point type, return the specified ...
Definition: Constants.cpp:2745
~ConstantDataSequential() override
Definition: Constants.h:578
uint64_t getZExtValue() const
Get zero extended value.
Definition: APInt.h:1327
VectorType * getType() const
getType - Specialize the getType() method to always return a VectorType, which reduces the amount of ...
Definition: Constants.h:787
bool isNaN() const
Returns true if and only if the float is a quiet or signaling NaN.
Definition: APFloat.h:424
size_t size() const
size - Get the string size.
Definition: StringRef.h:113
static Constant * getNSWAdd(Constant *C1, Constant *C2)
Definition: Constants.h:939
static Constant * getNaN(Type *Ty, bool Negative=false, unsigned type=0)
Definition: Constants.cpp:682
static Constant * getInfinity(Type *Ty, bool Negative=false)
Definition: Constants.cpp:742
UndefValue(Type *T)
Definition: Constants.h:1229
unsigned getBitWidth() const
getBitWidth - Return the bitwidth of this constant.
Definition: Constants.h:111
ConstantDataSequential(Type *ty, ValueTy VT, const char *Data)
Definition: Constants.h:576
bool isInfinity() const
isInfinity - Return true if the value is infinity
Definition: Constants.h:279
Constant * getElementAsConstant(unsigned i) const
getElementAsConstant - Return a Constant for a specified index's element.
Definition: Constants.cpp:2784
static Constant * getExactSDiv(Constant *C1, Constant *C2)
Definition: Constants.h:963
Constant * getSplatValue() const
getSplatValue - If this is a splat constant, meaning that all of the elements have the same value...
Definition: Constants.cpp:2813
static bool classof(const Value *V)
Methods for support type inquiry through isa, cast, and dyn_cast:
Definition: Constants.h:543
static Constant * getGetElementPtr(Type *Ty, Constant *C, ArrayRef< Constant * > IdxList, bool InBounds=false, Type *OnlyIfReducedTy=nullptr)
Getelementptr form.
Definition: Constants.h:1092
StringRef substr(size_t Start, size_t N=npos) const
Return a reference to the substring from [Start, Start + N).
Definition: StringRef.h:405
static Constant * getNUWShl(Constant *C1, Constant *C2)
Definition: Constants.h:960
uint64_t getLimitedValue(uint64_t Limit=~0ULL) const
If this value is smaller than the specified limit, return it, otherwise return the limit value...
Definition: APInt.h:404
F(f)
static bool classof(const Value *V)
Methods for support type inquiry through isa, cast, and dyn_cast:
Definition: Constants.h:832
FunctionType * getType(LLVMContext &Context, ID id, ArrayRef< Type * > Tys=None)
Return the function type for an intrinsic.
Definition: Function.cpp:822
unsigned getOpcode() const
getOpcode - Return the opcode at the root of this constant expression
Definition: Constants.h:1144
bool isMinusOne() const
This function will return true iff every bit in this constant is set to true.
Definition: Constants.h:177
DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant)
Transparently provide more efficient getOperand methods.
static bool classof(const Value *V)
Methods for support type inquiry through isa, cast, and dyn_cast:
Definition: Constants.h:1261
bool isMinValue(bool isSigned) const
This function will return true iff this constant represents the smallest value that may be represente...
Definition: Constants.h:198
ArrayType * getType() const
getType - Specialize the getType() method to always return an ArrayType, which reduces the amount of ...
Definition: Constants.h:725
bool isNegative() const
Determine sign of this APInt.
Definition: APInt.h:319
bool uge(uint64_t Num) const
This function will return true iff this constant represents a value with active bits bigger than 64 b...
Definition: Constants.h:210
BlockAddress - The address of a basic block.
Definition: Constants.h:802
StringRef getAsCString() const
getAsCString - If this array is isCString(), then this method returns the array (without the trailing...
Definition: Constants.h:654
const APInt & getValue() const
Return the constant as an APInt value reference.
Definition: Constants.h:106
static Constant * getNegativeZero(Type *Ty)
Definition: Constants.cpp:693
ArrayRef< T > makeArrayRef(const T &OneElt)
Construct an ArrayRef from a single element.
Definition: ArrayRef.h:308
UndefValue - 'undef' values are things that do not have specified contents.
Definition: Constants.h:1220
Constant * getSequentialElement() const
getSequentialElement - If this CAZ has array or vector type, return a zero with the right element typ...
Definition: Constants.cpp:773
StructType - Class to represent struct types.
Definition: DerivedTypes.h:191
A Use represents the edge between a Value definition and its users.
Definition: Use.h:69
static bool classof(const Value *V)
Methods for support type inquiry through isa, cast, and dyn_cast:
Definition: Constants.h:445
static Constant * getNUWNeg(Constant *C)
Definition: Constants.h:938
static Constant * getExactAShr(Constant *C1, Constant *C2)
Definition: Constants.h:969
double getElementAsDouble(unsigned i) const
getElementAsDouble - If this is an sequential container of doubles, return the specified element as a...
Definition: Constants.cpp:2773
static bool classof(const Value *V)
Methods for support type inquiry through isa, cast, and dyn_cast:
Definition: Constants.h:498
static bool classof(const Value *V)
Methods for support type inquiry through isa, cast, and dyn_cast:
Definition: Constants.h:731
#define false
Definition: ConvertUTF.c:65
This file implements a class to represent arbitrary precision integral constant values and operations...
bool isNegative() const
Definition: Constants.h:156
ConstantAggregateZero - All zero aggregate value.
Definition: Constants.h:307
uint64_t getZExtValue() const
Return the constant as a 64-bit unsigned integer value after it has been zero extended as appropriate...
Definition: Constants.h:117
ConstantPointerNull(PointerType *T)
Definition: Constants.h:522
#define DEFINE_TRANSPARENT_OPERAND_ACCESSORS(CLASS, VALUECLASS)
Macro for generating out-of-class operand accessor definitions.
ConstantExpr - a constant value that is initialized with an expression using other constant values...
Definition: Constants.h:852
static bool classof(const Value *V)
Methods for support type inquiry through isa, cast, and dyn_cast:
Definition: Constants.h:347
ConstantDataSequential - A vector or array constant whose element type is a simple 1/2/4/8-byte integ...
Definition: Constants.h:557
#define T
ArrayType - Class to represent array types.
Definition: DerivedTypes.h:336
uint64_t getLimitedValue(uint64_t Limit=~0ULL) const
getLimitedValue - If the value is smaller than the specified limit, return it, otherwise return the l...
Definition: Constants.h:219
static bool classof(const Value *V)
Methods for support type inquiry through isa, cast, and dyn_cast:
Definition: Constants.h:793
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: ArrayRef.h:31
unsigned getActiveBits() const
Compute the number of active bits in the value.
Definition: APInt.h:1297
SequentialType * getType() const
getType - Specialize the getType() method to always return a SequentialType, which reduces the amount...
Definition: Constants.h:619
bool isExactlyValue(double V) const
Definition: Constants.h:292
bool isZero() const
isZero - Return true if the value is positive or negative zero.
Definition: Constants.h:273
static Constant * getNSWNeg(Constant *C)
Definition: Constants.h:937
size_t size() const
size - Get the array size.
Definition: ArrayRef.h:134
PointerType - Class to represent pointers.
Definition: DerivedTypes.h:449
static Constant * getGetElementPtr(Type *Ty, Constant *C, Constant *Idx, bool InBounds=false, Type *OnlyIfReducedTy=nullptr)
Definition: Constants.h:1100
A self-contained host- and target-independent arbitrary-precision floating-point software implementat...
Definition: APFloat.h:122
bool isNaN() const
isNaN - Return true if the value is a NaN.
Definition: Constants.h:282
static Constant * getInBoundsGetElementPtr(Type *Ty, Constant *C, ArrayRef< Constant * > IdxList)
Create an "inbounds" getelementptr.
Definition: Constants.h:1115
ConstantExpr(Type *ty, unsigned Opcode, Use *Ops, unsigned NumOps)
Definition: Constants.h:860
static Constant * getImpl(StringRef Bytes, Type *Ty)
getImpl - This is the underlying implementation of all of the ConstantDataSequential::get methods...
Definition: Constants.cpp:2480
ConstantDataArray - An array constant whose element type is a simple 1/2/4/8-byte integer or float/do...
Definition: Constants.h:681
LLVM Basic Block Representation.
Definition: BasicBlock.h:65
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:45
This is an important class for using LLVM in a threaded context.
Definition: LLVMContext.h:41
static Constant * getFP(LLVMContext &Context, ArrayRef< uint16_t > Elts)
getFP() constructors - Return a constant with array type with an element count and element type of fl...
Definition: Constants.cpp:2588
bool isMaxValue(bool isSigned) const
This function will return true iff this constant represents the largest value that may be represented...
Definition: Constants.h:186
This is an important base class in LLVM.
Definition: Constant.h:41
bool isMaxSignedValue() const
Determine if this is the largest signed value.
Definition: APInt.h:353
uint64_t getElementByteSize() const
getElementByteSize - Return the size (in bytes) of each element in the array/vector.
Definition: Constants.cpp:2457
int64_t getSExtValue() const
Get sign extended value.
Definition: APInt.h:1339
StringRef getAsString() const
getAsString - If this array is isString(), then this method returns the array as a StringRef...
Definition: Constants.h:645
StringRef getRawDataValues() const
getRawDataValues - Return the raw, underlying, bytes of this data.
Definition: Constants.cpp:2425
static Constant * getFP(LLVMContext &Context, ArrayRef< uint16_t > Elts)
getFP() constructors - Return a constant with vector type with an element count and element type of f...
Definition: Constants.cpp:2665
ConstantFP - Floating Point Values [float, double].
Definition: Constants.h:233
static Constant * getNSWShl(Constant *C1, Constant *C2)
Definition: Constants.h:957
This file declares a class to represent arbitrary precision floating point values and provide a varie...
unsigned getBitWidth() const
Return the number of bits in the APInt.
Definition: APInt.h:1273
unsigned getValueID() const
Return an ID for the concrete type of this object.
Definition: Value.h:362
opStatus convert(const fltSemantics &, roundingMode, bool *)
APFloat::convert - convert a value of one floating point type to another.
Definition: APFloat.cpp:1972
static bool classof(const Value *V)
Methods for support type inquiry through isa, cast, and dyn_cast:
Definition: Constants.h:385
bool isMaxValue() const
Determine if this is the largest unsigned value.
Definition: APInt.h:347
static bool isValueValidForType(Type *Ty, const APFloat &V)
isValueValidForType - return true if Ty is big enough to represent V.
Definition: Constants.cpp:1326
static bool classof(const Value *V)
Methods to support type inquiry through isa, cast, and dyn_cast.
Definition: Constants.h:224
Class to represent integer types.
Definition: DerivedTypes.h:37
ConstantVector - Constant Vector Declarations.
Definition: Constants.h:461
static Constant * getSplat(unsigned NumElts, Constant *Elt)
getSplat - Return a ConstantVector with the specified constant in each element.
Definition: Constants.cpp:2684
uint64_t getElementAsInteger(unsigned i) const
getElementAsInteger - If this is a sequential container of integers (of any size), return the specified element in the low bits of a uint64_t.
Definition: Constants.cpp:2723
#define DECLARE_TRANSPARENT_OPERAND_ACCESSORS(VALUECLASS)
Macro for generating in-class operand accessor declarations.
#define LLVM_END_WITH_NULL
Definition: Compiler.h:116
static Constant * getInBoundsGetElementPtr(Type *Ty, Constant *C, Constant *Idx)
Definition: Constants.h:1119
bool isCString() const
isCString - This method returns true if the array "isString", ends with a nul byte, and does not contains any other nul bytes.
Definition: Constants.cpp:2798
hexagon gen pred
SequentialType - This is the superclass of the array, pointer and vector type classes.
Definition: DerivedTypes.h:310
static bool classof(const Value *V)
Methods for support type inquiry through isa, cast, and dyn_cast:
Definition: Constants.h:299
ArrayType * getType() const
getType - Specialize the getType() method to always return an ArrayType, which reduces the amount of ...
Definition: Constants.h:380
This is the shared class of boolean and integer constants.
Definition: Constants.h:47
bool isNegative() const
IEEE-754R isSignMinus: Returns true if and only if the current value is negative. ...
Definition: APFloat.h:399
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:222
ConstantPointerNull - a constant pointer value that points to null.
Definition: Constants.h:513
static Constant * getNUWMul(Constant *C1, Constant *C2)
Definition: Constants.h:954
BasicBlock * getBasicBlock() const
Definition: Constants.h:829
static Constant * getNSWSub(Constant *C1, Constant *C2)
Definition: Constants.h:945
bool equalsInt(uint64_t V) const
A helper method that can be used to determine if the constant contained within is equal to a constant...
Definition: Constants.h:133
static ConstantInt * getSigned(IntegerType *Ty, int64_t V)
Return a ConstantInt with the specified value for the specified type.
Definition: Constants.cpp:597
static bool classof(const Value *V)
Methods for support type inquiry through isa, cast, and dyn_cast:
Definition: Constants.h:1191
bool isZero() const
This is just a convenience method to make client code smaller for a common code.
Definition: Constants.h:161
static ConstantInt * getTrue(LLVMContext &Context)
Definition: Constants.cpp:530
ValueTy
Concrete subclass of this.
Definition: Value.h:343
void setValueSubclassData(unsigned short D)
Definition: Value.h:508
static BlockAddress * lookup(const BasicBlock *BB)
Lookup an existing BlockAddress constant for the given BasicBlock.
Definition: Constants.cpp:1514
VectorType - Class to represent vector types.
Definition: DerivedTypes.h:362
ConstantArray - Constant Array Declarations.
Definition: Constants.h:356
Class for arbitrary precision integers.
Definition: APInt.h:73
static Constant * getInBoundsGetElementPtr(Type *Ty, Constant *C, ArrayRef< Value * > IdxList)
Definition: Constants.h:1126
unsigned getNumElements() const
Return the number of elements in the array, vector, or struct.
Definition: Constants.cpp:799
static Constant * getAnon(LLVMContext &Ctx, ArrayRef< Constant * > V, bool Packed=false)
Definition: Constants.h:421
StructType * getType() const
getType() specialization - Reduce amount of casting...
Definition: Constants.h:440
static bool isElementTypeCompatible(const Type *Ty)
isElementTypeCompatible - Return true if a ConstantDataSequential can be formed with a vector or arra...
Definition: Constants.cpp:2433
bool isMinValue() const
Determine if this is the smallest unsigned value.
Definition: APInt.h:361
bool isAllOnesValue() const
Determine if all bits are set.
Definition: APInt.h:337
bool isNegative() const
isNegative - Return true if the sign bit is set.
Definition: Constants.h:276
Constant * getElementValue(Constant *C) const
getElementValue - Return a zero of the right value for the specified GEP index.
Definition: Constants.cpp:785
static Constant * getNSWMul(Constant *C1, Constant *C2)
Definition: Constants.h:951
bool isMinSignedValue() const
Determine if this is the smallest signed value.
Definition: APInt.h:367
float getElementAsFloat(unsigned i) const
getElementAsFloat - If this is an sequential container of floats, return the specified element as a f...
Definition: Constants.cpp:2764
static Constant * getExactLShr(Constant *C1, Constant *C2)
Definition: Constants.h:972
static Constant * getZeroValueForNegation(Type *Ty)
Floating point negation must be implemented with f(x) = -0.0 - x.
Definition: Constants.cpp:705
unsigned getNumElements() const
getNumElements - Return the number of elements in the array or vector.
Definition: Constants.cpp:2449
Compile-time customization of User operands.
Definition: User.h:34
bool isString() const
isString - This method returns true if this is an array of i8.
Definition: Constants.cpp:2792
PointerType * getType() const
getType - Specialize the getType() method to always return an PointerType, which reduces the amount o...
Definition: Constants.h:538
const APFloat & getValueAPF() const
Definition: Constants.h:270
VectorType * getType() const
getType - Specialize the getType() method to always return a VectorType, which reduces the amount of ...
Definition: Constants.h:489
bool isExactlyValue(const APFloat &V) const
isExactlyValue - We don't rely on operator== working on double values, as it returns true for things ...
Definition: Constants.cpp:758
Type * getElementType() const
getElementType - Return the element type of the array/vector.
Definition: Constants.cpp:2421
Function * getFunction() const
Definition: Constants.h:828
DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value)
Transparently provide more efficient getOperand methods.
LLVM Value Representation.
Definition: Value.h:69
bool isZero() const
Returns true if and only if the float is plus or minus zero.
Definition: APFloat.h:414
bool isInfinity() const
IEEE-754R isInfinite(): Returns true if and only if the float is infinity.
Definition: APFloat.h:421
Constant * getStructElement(unsigned Elt) const
getStructElement - If this CAZ has struct type, return a zero with the right element type for the spe...
Definition: Constants.cpp:779
C - The default llvm calling convention, compatible with C.
Definition: CallingConv.h:34
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:40
FixedNumOperandTraits - determine the allocation regime of the Use array when it is a prefix to the U...
Definition: OperandTraits.h:31
static Constant * getExactUDiv(Constant *C1, Constant *C2)
Definition: Constants.h:966
static bool classof(const Value *V)
Methods for support type inquiry through isa, cast, and dyn_cast:
Definition: Constants.h:667
VariadicOperandTraits - determine the allocation regime of the Use array when it is a prefix to the U...
Definition: OperandTraits.h:66
static Constant * getNUWSub(Constant *C1, Constant *C2)
Definition: Constants.h:948
int64_t getSExtValue() const
Return the constant as a 64-bit integer value after it has been sign extended as appropriate for the ...
Definition: Constants.h:125
static Constant * getNUWAdd(Constant *C1, Constant *C2)
Definition: Constants.h:942
const T * data() const
Definition: ArrayRef.h:131
Constant * getWithOperands(ArrayRef< Constant * > Ops) const
getWithOperands - This returns the current constant expression with the operands replaced with the sp...
Definition: Constants.h:1164
const fltSemantics & getSemantics() const
Definition: APFloat.h:435
bool isOne() const
This is just a convenience method to make client code smaller for a common case.
Definition: Constants.h:169