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Value.h
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1 //===- llvm/Value.h - Definition of the Value class -------------*- 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 // This file declares the Value class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_IR_VALUE_H
15 #define LLVM_IR_VALUE_H
16 
17 #include "llvm-c/Types.h"
19 #include "llvm/IR/Use.h"
21 #include "llvm/Support/Casting.h"
22 #include <cassert>
23 #include <iterator>
24 #include <memory>
25 
26 namespace llvm {
27 
28 class APInt;
29 class Argument;
30 class BasicBlock;
31 class Constant;
32 class ConstantData;
33 class ConstantAggregate;
34 class DataLayout;
35 class Function;
36 class GlobalAlias;
37 class GlobalIFunc;
38 class GlobalIndirectSymbol;
39 class GlobalObject;
40 class GlobalValue;
41 class GlobalVariable;
42 class InlineAsm;
43 class Instruction;
44 class LLVMContext;
45 class Module;
46 class ModuleSlotTracker;
47 class raw_ostream;
48 template<typename ValueTy> class StringMapEntry;
49 class StringRef;
50 class Twine;
51 class Type;
52 class User;
53 
55 
56 //===----------------------------------------------------------------------===//
57 // Value Class
58 //===----------------------------------------------------------------------===//
59 
60 /// \brief LLVM Value Representation
61 ///
62 /// This is a very important LLVM class. It is the base class of all values
63 /// computed by a program that may be used as operands to other values. Value is
64 /// the super class of other important classes such as Instruction and Function.
65 /// All Values have a Type. Type is not a subclass of Value. Some values can
66 /// have a name and they belong to some Module. Setting the name on the Value
67 /// automatically updates the module's symbol table.
68 ///
69 /// Every value has a "use list" that keeps track of which other Values are
70 /// using this Value. A Value can also have an arbitrary number of ValueHandle
71 /// objects that watch it and listen to RAUW and Destroy events. See
72 /// llvm/IR/ValueHandle.h for details.
73 class Value {
74  // The least-significant bit of the first word of Value *must* be zero:
75  // http://www.llvm.org/docs/ProgrammersManual.html#the-waymarking-algorithm
76  Type *VTy;
77  Use *UseList;
78 
79  friend class ValueAsMetadata; // Allow access to IsUsedByMD.
80  friend class ValueHandleBase;
81 
82  const unsigned char SubclassID; // Subclass identifier (for isa/dyn_cast)
83  unsigned char HasValueHandle : 1; // Has a ValueHandle pointing to this?
84 
85 protected:
86  /// \brief Hold subclass data that can be dropped.
87  ///
88  /// This member is similar to SubclassData, however it is for holding
89  /// information which may be used to aid optimization, but which may be
90  /// cleared to zero without affecting conservative interpretation.
91  unsigned char SubclassOptionalData : 7;
92 
93 private:
94  /// \brief Hold arbitrary subclass data.
95  ///
96  /// This member is defined by this class, but is not used for anything.
97  /// Subclasses can use it to hold whatever state they find useful. This
98  /// field is initialized to zero by the ctor.
99  unsigned short SubclassData;
100 
101 protected:
102  /// \brief The number of operands in the subclass.
103  ///
104  /// This member is defined by this class, but not used for anything.
105  /// Subclasses can use it to store their number of operands, if they have
106  /// any.
107  ///
108  /// This is stored here to save space in User on 64-bit hosts. Since most
109  /// instances of Value have operands, 32-bit hosts aren't significantly
110  /// affected.
111  ///
112  /// Note, this should *NOT* be used directly by any class other than User.
113  /// User uses this value to find the Use list.
114  enum : unsigned { NumUserOperandsBits = 28 };
116 
117  // Use the same type as the bitfield above so that MSVC will pack them.
118  unsigned IsUsedByMD : 1;
119  unsigned HasName : 1;
120  unsigned HasHungOffUses : 1;
121  unsigned HasDescriptor : 1;
122 
123 private:
124  template <typename UseT> // UseT == 'Use' or 'const Use'
125  class use_iterator_impl
126  : public std::iterator<std::forward_iterator_tag, UseT *> {
127  friend class Value;
128 
129  UseT *U;
130 
131  explicit use_iterator_impl(UseT *u) : U(u) {}
132 
133  public:
134  use_iterator_impl() : U() {}
135 
136  bool operator==(const use_iterator_impl &x) const { return U == x.U; }
137  bool operator!=(const use_iterator_impl &x) const { return !operator==(x); }
138 
139  use_iterator_impl &operator++() { // Preincrement
140  assert(U && "Cannot increment end iterator!");
141  U = U->getNext();
142  return *this;
143  }
144 
145  use_iterator_impl operator++(int) { // Postincrement
146  auto tmp = *this;
147  ++*this;
148  return tmp;
149  }
150 
151  UseT &operator*() const {
152  assert(U && "Cannot dereference end iterator!");
153  return *U;
154  }
155 
156  UseT *operator->() const { return &operator*(); }
157 
158  operator use_iterator_impl<const UseT>() const {
159  return use_iterator_impl<const UseT>(U);
160  }
161  };
162 
163  template <typename UserTy> // UserTy == 'User' or 'const User'
164  class user_iterator_impl
165  : public std::iterator<std::forward_iterator_tag, UserTy *> {
166  use_iterator_impl<Use> UI;
167  explicit user_iterator_impl(Use *U) : UI(U) {}
168  friend class Value;
169 
170  public:
171  user_iterator_impl() = default;
172 
173  bool operator==(const user_iterator_impl &x) const { return UI == x.UI; }
174  bool operator!=(const user_iterator_impl &x) const { return !operator==(x); }
175 
176  /// \brief Returns true if this iterator is equal to user_end() on the value.
177  bool atEnd() const { return *this == user_iterator_impl(); }
178 
179  user_iterator_impl &operator++() { // Preincrement
180  ++UI;
181  return *this;
182  }
183 
184  user_iterator_impl operator++(int) { // Postincrement
185  auto tmp = *this;
186  ++*this;
187  return tmp;
188  }
189 
190  // Retrieve a pointer to the current User.
191  UserTy *operator*() const {
192  return UI->getUser();
193  }
194 
195  UserTy *operator->() const { return operator*(); }
196 
197  operator user_iterator_impl<const UserTy>() const {
198  return user_iterator_impl<const UserTy>(*UI);
199  }
200 
201  Use &getUse() const { return *UI; }
202  };
203 
204 protected:
205  Value(Type *Ty, unsigned scid);
206 
207  /// Value's destructor should be virtual by design, but that would require
208  /// that Value and all of its subclasses have a vtable that effectively
209  /// duplicates the information in the value ID. As a size optimization, the
210  /// destructor has been protected, and the caller should manually call
211  /// deleteValue.
212  ~Value(); // Use deleteValue() to delete a generic Value.
213 
214 public:
215  Value(const Value &) = delete;
216  Value &operator=(const Value &) = delete;
217 
218  /// Delete a pointer to a generic Value.
219  void deleteValue();
220 
221  /// \brief Support for debugging, callable in GDB: V->dump()
222  void dump() const;
223 
224  /// \brief Implement operator<< on Value.
225  /// @{
226  void print(raw_ostream &O, bool IsForDebug = false) const;
227  void print(raw_ostream &O, ModuleSlotTracker &MST,
228  bool IsForDebug = false) const;
229  /// @}
230 
231  /// \brief Print the name of this Value out to the specified raw_ostream.
232  ///
233  /// This is useful when you just want to print 'int %reg126', not the
234  /// instruction that generated it. If you specify a Module for context, then
235  /// even constanst get pretty-printed; for example, the type of a null
236  /// pointer is printed symbolically.
237  /// @{
238  void printAsOperand(raw_ostream &O, bool PrintType = true,
239  const Module *M = nullptr) const;
240  void printAsOperand(raw_ostream &O, bool PrintType,
241  ModuleSlotTracker &MST) const;
242  /// @}
243 
244  /// \brief All values are typed, get the type of this value.
245  Type *getType() const { return VTy; }
246 
247  /// \brief All values hold a context through their type.
248  LLVMContext &getContext() const;
249 
250  // \brief All values can potentially be named.
251  bool hasName() const { return HasName; }
252  ValueName *getValueName() const;
253  void setValueName(ValueName *VN);
254 
255 private:
256  void destroyValueName();
257  void doRAUW(Value *New, bool NoMetadata);
258  void setNameImpl(const Twine &Name);
259 
260 public:
261  /// \brief Return a constant reference to the value's name.
262  ///
263  /// This guaranteed to return the same reference as long as the value is not
264  /// modified. If the value has a name, this does a hashtable lookup, so it's
265  /// not free.
266  StringRef getName() const;
267 
268  /// \brief Change the name of the value.
269  ///
270  /// Choose a new unique name if the provided name is taken.
271  ///
272  /// \param Name The new name; or "" if the value's name should be removed.
273  void setName(const Twine &Name);
274 
275  /// \brief Transfer the name from V to this value.
276  ///
277  /// After taking V's name, sets V's name to empty.
278  ///
279  /// \note It is an error to call V->takeName(V).
280  void takeName(Value *V);
281 
282  /// \brief Change all uses of this to point to a new Value.
283  ///
284  /// Go through the uses list for this definition and make each use point to
285  /// "V" instead of "this". After this completes, 'this's use list is
286  /// guaranteed to be empty.
287  void replaceAllUsesWith(Value *V);
288 
289  /// \brief Change non-metadata uses of this to point to a new Value.
290  ///
291  /// Go through the uses list for this definition and make each use point to
292  /// "V" instead of "this". This function skips metadata entries in the list.
294 
295  /// replaceUsesOutsideBlock - Go through the uses list for this definition and
296  /// make each use point to "V" instead of "this" when the use is outside the
297  /// block. 'This's use list is expected to have at least one element.
298  /// Unlike replaceAllUsesWith this function does not support basic block
299  /// values or constant users.
301 
302  //----------------------------------------------------------------------
303  // Methods for handling the chain of uses of this Value.
304  //
305  // Materializing a function can introduce new uses, so these methods come in
306  // two variants:
307  // The methods that start with materialized_ check the uses that are
308  // currently known given which functions are materialized. Be very careful
309  // when using them since you might not get all uses.
310  // The methods that don't start with materialized_ assert that modules is
311  // fully materialized.
312  void assertModuleIsMaterializedImpl() const;
313  // This indirection exists so we can keep assertModuleIsMaterializedImpl()
314  // around in release builds of Value.cpp to be linked with other code built
315  // in debug mode. But this avoids calling it in any of the release built code.
317 #ifndef NDEBUG
319 #endif
320  }
321 
322  bool use_empty() const {
324  return UseList == nullptr;
325  }
326 
327  using use_iterator = use_iterator_impl<Use>;
328  using const_use_iterator = use_iterator_impl<const Use>;
329 
332  return const_use_iterator(UseList);
333  }
336  return materialized_use_begin();
337  }
340  return materialized_use_begin();
341  }
346  }
349  }
352  return materialized_uses();
353  }
356  return materialized_uses();
357  }
358 
359  bool user_empty() const {
361  return UseList == nullptr;
362  }
363 
364  using user_iterator = user_iterator_impl<User>;
365  using const_user_iterator = user_iterator_impl<const User>;
366 
369  return const_user_iterator(UseList);
370  }
373  return materialized_user_begin();
374  }
377  return materialized_user_begin();
378  }
383  return *materialized_user_begin();
384  }
385  const User *user_back() const {
387  return *materialized_user_begin();
388  }
391  }
394  }
397  return materialized_users();
398  }
401  return materialized_users();
402  }
403 
404  /// \brief Return true if there is exactly one user of this value.
405  ///
406  /// This is specialized because it is a common request and does not require
407  /// traversing the whole use list.
408  bool hasOneUse() const {
410  if (I == E) return false;
411  return ++I == E;
412  }
413 
414  /// \brief Return true if this Value has exactly N users.
415  bool hasNUses(unsigned N) const;
416 
417  /// \brief Return true if this value has N users or more.
418  ///
419  /// This is logically equivalent to getNumUses() >= N.
420  bool hasNUsesOrMore(unsigned N) const;
421 
422  /// \brief Check if this value is used in the specified basic block.
423  bool isUsedInBasicBlock(const BasicBlock *BB) const;
424 
425  /// \brief This method computes the number of uses of this Value.
426  ///
427  /// This is a linear time operation. Use hasOneUse, hasNUses, or
428  /// hasNUsesOrMore to check for specific values.
429  unsigned getNumUses() const;
430 
431  /// \brief This method should only be used by the Use class.
432  void addUse(Use &U) { U.addToList(&UseList); }
433 
434  /// \brief Concrete subclass of this.
435  ///
436  /// An enumeration for keeping track of the concrete subclass of Value that
437  /// is actually instantiated. Values of this enumeration are kept in the
438  /// Value classes SubclassID field. They are used for concrete type
439  /// identification.
440  enum ValueTy {
441 #define HANDLE_VALUE(Name) Name##Val,
442 #include "llvm/IR/Value.def"
443 
444  // Markers:
445 #define HANDLE_CONSTANT_MARKER(Marker, Constant) Marker = Constant##Val,
446 #include "llvm/IR/Value.def"
447  };
448 
449  /// \brief Return an ID for the concrete type of this object.
450  ///
451  /// This is used to implement the classof checks. This should not be used
452  /// for any other purpose, as the values may change as LLVM evolves. Also,
453  /// note that for instructions, the Instruction's opcode is added to
454  /// InstructionVal. So this means three things:
455  /// # there is no value with code InstructionVal (no opcode==0).
456  /// # there are more possible values for the value type than in ValueTy enum.
457  /// # the InstructionVal enumerator must be the highest valued enumerator in
458  /// the ValueTy enum.
459  unsigned getValueID() const {
460  return SubclassID;
461  }
462 
463  /// \brief Return the raw optional flags value contained in this value.
464  ///
465  /// This should only be used when testing two Values for equivalence.
466  unsigned getRawSubclassOptionalData() const {
467  return SubclassOptionalData;
468  }
469 
470  /// \brief Clear the optional flags contained in this value.
473  }
474 
475  /// \brief Check the optional flags for equality.
476  bool hasSameSubclassOptionalData(const Value *V) const {
478  }
479 
480  /// \brief Return true if there is a value handle associated with this value.
481  bool hasValueHandle() const { return HasValueHandle; }
482 
483  /// \brief Return true if there is metadata referencing this value.
484  bool isUsedByMetadata() const { return IsUsedByMD; }
485 
486  /// \brief Return true if this value is a swifterror value.
487  ///
488  /// swifterror values can be either a function argument or an alloca with a
489  /// swifterror attribute.
490  bool isSwiftError() const;
491 
492  /// \brief Strip off pointer casts, all-zero GEPs, and aliases.
493  ///
494  /// Returns the original uncasted value. If this is called on a non-pointer
495  /// value, it returns 'this'.
496  const Value *stripPointerCasts() const;
498  return const_cast<Value *>(
499  static_cast<const Value *>(this)->stripPointerCasts());
500  }
501 
502  /// \brief Strip off pointer casts, all-zero GEPs, aliases and barriers.
503  ///
504  /// Returns the original uncasted value. If this is called on a non-pointer
505  /// value, it returns 'this'. This function should be used only in
506  /// Alias analysis.
507  const Value *stripPointerCastsAndBarriers() const;
509  return const_cast<Value *>(
510  static_cast<const Value *>(this)->stripPointerCastsAndBarriers());
511  }
512 
513  /// \brief Strip off pointer casts and all-zero GEPs.
514  ///
515  /// Returns the original uncasted value. If this is called on a non-pointer
516  /// value, it returns 'this'.
519  return const_cast<Value *>(
520  static_cast<const Value *>(this)->stripPointerCastsNoFollowAliases());
521  }
522 
523  /// \brief Strip off pointer casts and all-constant inbounds GEPs.
524  ///
525  /// Returns the original pointer value. If this is called on a non-pointer
526  /// value, it returns 'this'.
527  const Value *stripInBoundsConstantOffsets() const;
529  return const_cast<Value *>(
530  static_cast<const Value *>(this)->stripInBoundsConstantOffsets());
531  }
532 
533  /// \brief Accumulate offsets from \a stripInBoundsConstantOffsets().
534  ///
535  /// Stores the resulting constant offset stripped into the APInt provided.
536  /// The provided APInt will be extended or truncated as needed to be the
537  /// correct bitwidth for an offset of this pointer type.
538  ///
539  /// If this is called on a non-pointer value, it returns 'this'.
541  APInt &Offset) const;
543  APInt &Offset) {
544  return const_cast<Value *>(static_cast<const Value *>(this)
546  }
547 
548  /// \brief Strip off pointer casts and inbounds GEPs.
549  ///
550  /// Returns the original pointer value. If this is called on a non-pointer
551  /// value, it returns 'this'.
552  const Value *stripInBoundsOffsets() const;
554  return const_cast<Value *>(
555  static_cast<const Value *>(this)->stripInBoundsOffsets());
556  }
557 
558  /// \brief Returns the number of bytes known to be dereferenceable for the
559  /// pointer value.
560  ///
561  /// If CanBeNull is set by this function the pointer can either be null or be
562  /// dereferenceable up to the returned number of bytes.
563  unsigned getPointerDereferenceableBytes(const DataLayout &DL,
564  bool &CanBeNull) const;
565 
566  /// \brief Returns an alignment of the pointer value.
567  ///
568  /// Returns an alignment which is either specified explicitly, e.g. via
569  /// align attribute of a function argument, or guaranteed by DataLayout.
570  unsigned getPointerAlignment(const DataLayout &DL) const;
571 
572  /// \brief Translate PHI node to its predecessor from the given basic block.
573  ///
574  /// If this value is a PHI node with CurBB as its parent, return the value in
575  /// the PHI node corresponding to PredBB. If not, return ourself. This is
576  /// useful if you want to know the value something has in a predecessor
577  /// block.
578  const Value *DoPHITranslation(const BasicBlock *CurBB,
579  const BasicBlock *PredBB) const;
580  Value *DoPHITranslation(const BasicBlock *CurBB, const BasicBlock *PredBB) {
581  return const_cast<Value *>(
582  static_cast<const Value *>(this)->DoPHITranslation(CurBB, PredBB));
583  }
584 
585  /// \brief The maximum alignment for instructions.
586  ///
587  /// This is the greatest alignment value supported by load, store, and alloca
588  /// instructions, and global values.
589  static const unsigned MaxAlignmentExponent = 29;
590  static const unsigned MaximumAlignment = 1u << MaxAlignmentExponent;
591 
592  /// \brief Mutate the type of this Value to be of the specified type.
593  ///
594  /// Note that this is an extremely dangerous operation which can create
595  /// completely invalid IR very easily. It is strongly recommended that you
596  /// recreate IR objects with the right types instead of mutating them in
597  /// place.
598  void mutateType(Type *Ty) {
599  VTy = Ty;
600  }
601 
602  /// \brief Sort the use-list.
603  ///
604  /// Sorts the Value's use-list by Cmp using a stable mergesort. Cmp is
605  /// expected to compare two \a Use references.
606  template <class Compare> void sortUseList(Compare Cmp);
607 
608  /// \brief Reverse the use-list.
609  void reverseUseList();
610 
611 private:
612  /// \brief Merge two lists together.
613  ///
614  /// Merges \c L and \c R using \c Cmp. To enable stable sorts, always pushes
615  /// "equal" items from L before items from R.
616  ///
617  /// \return the first element in the list.
618  ///
619  /// \note Completely ignores \a Use::Prev (doesn't read, doesn't update).
620  template <class Compare>
621  static Use *mergeUseLists(Use *L, Use *R, Compare Cmp) {
622  Use *Merged;
623  Use **Next = &Merged;
624 
625  while (true) {
626  if (!L) {
627  *Next = R;
628  break;
629  }
630  if (!R) {
631  *Next = L;
632  break;
633  }
634  if (Cmp(*R, *L)) {
635  *Next = R;
636  Next = &R->Next;
637  R = R->Next;
638  } else {
639  *Next = L;
640  Next = &L->Next;
641  L = L->Next;
642  }
643  }
644 
645  return Merged;
646  }
647 
648  /// \brief Tail-recursive helper for \a mergeUseLists().
649  ///
650  /// \param[out] Next the first element in the list.
651  template <class Compare>
652  static void mergeUseListsImpl(Use *L, Use *R, Use **Next, Compare Cmp);
653 
654 protected:
655  unsigned short getSubclassDataFromValue() const { return SubclassData; }
656  void setValueSubclassData(unsigned short D) { SubclassData = D; }
657 };
658 
659 struct ValueDeleter { void operator()(Value *V) { V->deleteValue(); } };
660 
661 /// Use this instead of std::unique_ptr<Value> or std::unique_ptr<Instruction>.
662 /// Those don't work because Value and Instruction's destructors are protected,
663 /// aren't virtual, and won't destroy the complete object.
664 using unique_value = std::unique_ptr<Value, ValueDeleter>;
665 
666 inline raw_ostream &operator<<(raw_ostream &OS, const Value &V) {
667  V.print(OS);
668  return OS;
669 }
670 
671 void Use::set(Value *V) {
672  if (Val) removeFromList();
673  Val = V;
674  if (V) V->addUse(*this);
675 }
676 
678  set(RHS);
679  return RHS;
680 }
681 
682 const Use &Use::operator=(const Use &RHS) {
683  set(RHS.Val);
684  return *this;
685 }
686 
687 template <class Compare> void Value::sortUseList(Compare Cmp) {
688  if (!UseList || !UseList->Next)
689  // No need to sort 0 or 1 uses.
690  return;
691 
692  // Note: this function completely ignores Prev pointers until the end when
693  // they're fixed en masse.
694 
695  // Create a binomial vector of sorted lists, visiting uses one at a time and
696  // merging lists as necessary.
697  const unsigned MaxSlots = 32;
698  Use *Slots[MaxSlots];
699 
700  // Collect the first use, turning it into a single-item list.
701  Use *Next = UseList->Next;
702  UseList->Next = nullptr;
703  unsigned NumSlots = 1;
704  Slots[0] = UseList;
705 
706  // Collect all but the last use.
707  while (Next->Next) {
708  Use *Current = Next;
709  Next = Current->Next;
710 
711  // Turn Current into a single-item list.
712  Current->Next = nullptr;
713 
714  // Save Current in the first available slot, merging on collisions.
715  unsigned I;
716  for (I = 0; I < NumSlots; ++I) {
717  if (!Slots[I])
718  break;
719 
720  // Merge two lists, doubling the size of Current and emptying slot I.
721  //
722  // Since the uses in Slots[I] originally preceded those in Current, send
723  // Slots[I] in as the left parameter to maintain a stable sort.
724  Current = mergeUseLists(Slots[I], Current, Cmp);
725  Slots[I] = nullptr;
726  }
727  // Check if this is a new slot.
728  if (I == NumSlots) {
729  ++NumSlots;
730  assert(NumSlots <= MaxSlots && "Use list bigger than 2^32");
731  }
732 
733  // Found an open slot.
734  Slots[I] = Current;
735  }
736 
737  // Merge all the lists together.
738  assert(Next && "Expected one more Use");
739  assert(!Next->Next && "Expected only one Use");
740  UseList = Next;
741  for (unsigned I = 0; I < NumSlots; ++I)
742  if (Slots[I])
743  // Since the uses in Slots[I] originally preceded those in UseList, send
744  // Slots[I] in as the left parameter to maintain a stable sort.
745  UseList = mergeUseLists(Slots[I], UseList, Cmp);
746 
747  // Fix the Prev pointers.
748  for (Use *I = UseList, **Prev = &UseList; I; I = I->Next) {
749  I->setPrev(Prev);
750  Prev = &I->Next;
751  }
752 }
753 
754 // isa - Provide some specializations of isa so that we don't have to include
755 // the subtype header files to test to see if the value is a subclass...
756 //
757 template <> struct isa_impl<Constant, Value> {
758  static inline bool doit(const Value &Val) {
759  return Val.getValueID() >= Value::ConstantFirstVal &&
760  Val.getValueID() <= Value::ConstantLastVal;
761  }
762 };
763 
764 template <> struct isa_impl<ConstantData, Value> {
765  static inline bool doit(const Value &Val) {
766  return Val.getValueID() >= Value::ConstantDataFirstVal &&
767  Val.getValueID() <= Value::ConstantDataLastVal;
768  }
769 };
770 
771 template <> struct isa_impl<ConstantAggregate, Value> {
772  static inline bool doit(const Value &Val) {
773  return Val.getValueID() >= Value::ConstantAggregateFirstVal &&
774  Val.getValueID() <= Value::ConstantAggregateLastVal;
775  }
776 };
777 
778 template <> struct isa_impl<Argument, Value> {
779  static inline bool doit (const Value &Val) {
780  return Val.getValueID() == Value::ArgumentVal;
781  }
782 };
783 
784 template <> struct isa_impl<InlineAsm, Value> {
785  static inline bool doit(const Value &Val) {
786  return Val.getValueID() == Value::InlineAsmVal;
787  }
788 };
789 
790 template <> struct isa_impl<Instruction, Value> {
791  static inline bool doit(const Value &Val) {
792  return Val.getValueID() >= Value::InstructionVal;
793  }
794 };
795 
796 template <> struct isa_impl<BasicBlock, Value> {
797  static inline bool doit(const Value &Val) {
798  return Val.getValueID() == Value::BasicBlockVal;
799  }
800 };
801 
802 template <> struct isa_impl<Function, Value> {
803  static inline bool doit(const Value &Val) {
804  return Val.getValueID() == Value::FunctionVal;
805  }
806 };
807 
808 template <> struct isa_impl<GlobalVariable, Value> {
809  static inline bool doit(const Value &Val) {
810  return Val.getValueID() == Value::GlobalVariableVal;
811  }
812 };
813 
814 template <> struct isa_impl<GlobalAlias, Value> {
815  static inline bool doit(const Value &Val) {
816  return Val.getValueID() == Value::GlobalAliasVal;
817  }
818 };
819 
820 template <> struct isa_impl<GlobalIFunc, Value> {
821  static inline bool doit(const Value &Val) {
822  return Val.getValueID() == Value::GlobalIFuncVal;
823  }
824 };
825 
826 template <> struct isa_impl<GlobalIndirectSymbol, Value> {
827  static inline bool doit(const Value &Val) {
828  return isa<GlobalAlias>(Val) || isa<GlobalIFunc>(Val);
829  }
830 };
831 
832 template <> struct isa_impl<GlobalValue, Value> {
833  static inline bool doit(const Value &Val) {
834  return isa<GlobalObject>(Val) || isa<GlobalIndirectSymbol>(Val);
835  }
836 };
837 
838 template <> struct isa_impl<GlobalObject, Value> {
839  static inline bool doit(const Value &Val) {
840  return isa<GlobalVariable>(Val) || isa<Function>(Val);
841  }
842 };
843 
844 // Create wrappers for C Binding types (see CBindingWrapping.h).
846 
847 // Specialized opaque value conversions.
849  return reinterpret_cast<Value**>(Vals);
850 }
851 
852 template<typename T>
853 inline T **unwrap(LLVMValueRef *Vals, unsigned Length) {
854 #ifndef NDEBUG
855  for (LLVMValueRef *I = Vals, *E = Vals + Length; I != E; ++I)
856  unwrap<T>(*I); // For side effect of calling assert on invalid usage.
857 #endif
858  (void)Length;
859  return reinterpret_cast<T**>(Vals);
860 }
861 
862 inline LLVMValueRef *wrap(const Value **Vals) {
863  return reinterpret_cast<LLVMValueRef*>(const_cast<Value**>(Vals));
864 }
865 
866 } // end namespace llvm
867 
868 #endif // LLVM_IR_VALUE_H
This is the common base class of value handles.
Definition: ValueHandle.h:30
unsigned short getSubclassDataFromValue() const
Definition: Value.h:655
void sortUseList(Compare Cmp)
Sort the use-list.
Definition: Value.h:687
use_iterator use_end()
Definition: Value.h:342
A parsed version of the target data layout string in and methods for querying it. ...
Definition: DataLayout.h:109
unsigned HasDescriptor
Definition: Value.h:121
iterator_range< use_iterator > uses()
Definition: Value.h:350
void operator()(Value *V)
Definition: Value.h:659
This class represents an incoming formal argument to a Function.
Definition: Argument.h:30
unsigned getValueID() const
Return an ID for the concrete type of this object.
Definition: Value.h:459
const Value * stripInBoundsOffsets() const
Strip off pointer casts and inbounds GEPs.
Definition: Value.cpp:587
static bool doit(const Value &Val)
Definition: Value.h:772
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
void addUse(Use &U)
This method should only be used by the Use class.
Definition: Value.h:432
StringMapEntry - This is used to represent one value that is inserted into a StringMap.
Definition: StringMap.h:126
Various leaf nodes.
Definition: ISDOpcodes.h:60
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:63
bool user_empty() const
Definition: Value.h:359
const Value * stripPointerCastsAndBarriers() const
Strip off pointer casts, all-zero GEPs, aliases and barriers.
Definition: Value.cpp:539
This provides a very simple, boring adaptor for a begin and end iterator into a range type...
use_iterator materialized_use_begin()
Definition: Value.h:330
bool hasValueHandle() const
Return true if there is a value handle associated with this value.
Definition: Value.h:481
iterator_range< const_user_iterator > users() const
Definition: Value.h:399
LLVMContext & getContext() const
All values hold a context through their type.
Definition: Value.cpp:697
static bool doit(const Value &Val)
Definition: Value.h:809
void deleteValue()
Delete a pointer to a generic Value.
Definition: Value.cpp:93
Manage lifetime of a slot tracker for printing IR.
This defines the Use class.
use_iterator_impl< const Use > const_use_iterator
Definition: Value.h:328
const Value * DoPHITranslation(const BasicBlock *CurBB, const BasicBlock *PredBB) const
Translate PHI node to its predecessor from the given basic block.
Definition: Value.cpp:689
unsigned getPointerAlignment(const DataLayout &DL) const
Returns an alignment of the pointer value.
Definition: Value.cpp:642
iterator_range< user_iterator > materialized_users()
Definition: Value.h:389
void dump() const
Support for debugging, callable in GDB: V->dump()
Definition: AsmWriter.cpp:3627
const_user_iterator materialized_user_begin() const
Definition: Value.h:368
iterator_range< const_user_iterator > materialized_users() const
Definition: Value.h:392
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:81
Attribute unwrap(LLVMAttributeRef Attr)
Definition: Attributes.h:195
A Use represents the edge between a Value definition and its users.
Definition: Use.h:56
void setName(const Twine &Name)
Change the name of the value.
Definition: Value.cpp:284
void assertModuleIsMaterializedImpl() const
Definition: Value.cpp:350
static bool doit(const Value &Val)
Definition: Value.h:797
static const unsigned MaximumAlignment
Definition: Value.h:590
#define DEFINE_ISA_CONVERSION_FUNCTIONS(ty, ref)
APInt operator*(APInt a, uint64_t RHS)
Definition: APInt.h:2070
static bool doit(const Value &Val)
Definition: Value.h:785
unsigned getPointerDereferenceableBytes(const DataLayout &DL, bool &CanBeNull) const
Returns the number of bytes known to be dereferenceable for the pointer value.
Definition: Value.cpp:591
Value * stripInBoundsOffsets()
Definition: Value.h:553
unsigned HasHungOffUses
Definition: Value.h:120
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:245
iterator_range< const_use_iterator > materialized_uses() const
Definition: Value.h:347
bool isSwiftError() const
Return true if this value is a swifterror value.
Definition: Value.cpp:718
static bool doit(const Value &Val)
Definition: Value.h:827
const_use_iterator use_end() const
Definition: Value.h:343
const_use_iterator materialized_use_begin() const
Definition: Value.h:331
Value * stripPointerCastsNoFollowAliases()
Definition: Value.h:518
void replaceAllUsesWith(Value *V)
Change all uses of this to point to a new Value.
Definition: Value.cpp:428
Value wrapper in the Metadata hierarchy.
Definition: Metadata.h:337
void takeName(Value *V)
Transfer the name from V to this value.
Definition: Value.cpp:290
use_iterator_impl< Use > use_iterator
Definition: Value.h:327
unsigned getRawSubclassOptionalData() const
Return the raw optional flags value contained in this value.
Definition: Value.h:466
const_use_iterator use_begin() const
Definition: Value.h:338
bool hasNUsesOrMore(unsigned N) const
Return true if this value has N users or more.
Definition: Value.cpp:134
bool hasNUses(unsigned N) const
Return true if this Value has exactly N users.
Definition: Value.cpp:126
void set(Value *Val)
Definition: Value.h:671
bool hasName() const
Definition: Value.h:251
LLVM Basic Block Representation.
Definition: BasicBlock.h:59
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:46
This is an important class for using LLVM in a threaded context.
Definition: LLVMContext.h:69
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
This is an important base class in LLVM.
Definition: Constant.h:42
void replaceNonMetadataUsesWith(Value *V)
Change non-metadata uses of this to point to a new Value.
Definition: Value.cpp:432
amdgpu inline
iterator_range< use_iterator > materialized_uses()
Definition: Value.h:344
bool isUsedInBasicBlock(const BasicBlock *BB) const
Check if this value is used in the specified basic block.
Definition: Value.cpp:143
bool hasSameSubclassOptionalData(const Value *V) const
Check the optional flags for equality.
Definition: Value.h:476
static bool doit(const Value &Val)
Definition: Value.h:821
void print(raw_ostream &O, bool IsForDebug=false) const
Implement operator<< on Value.
Definition: AsmWriter.cpp:3480
Value * stripInBoundsConstantOffsets()
Definition: Value.h:528
const Value * stripPointerCasts() const
Strip off pointer casts, all-zero GEPs, and aliases.
Definition: Value.cpp:527
Value(Type *Ty, unsigned scid)
Definition: Value.cpp:49
void printAsOperand(raw_ostream &O, bool PrintType=true, const Module *M=nullptr) const
Print the name of this Value out to the specified raw_ostream.
Definition: AsmWriter.cpp:3559
Value * stripPointerCasts()
Definition: Value.h:497
Value & operator=(const Value &)=delete
unsigned char SubclassOptionalData
Hold subclass data that can be dropped.
Definition: Value.h:91
iterator_range< T > make_range(T x, T y)
Convenience function for iterating over sub-ranges.
static const unsigned MaxAlignmentExponent
The maximum alignment for instructions.
Definition: Value.h:589
unsigned IsUsedByMD
Definition: Value.h:118
void assertModuleIsMaterialized() const
Definition: Value.h:316
static bool doit(const Value &Val)
Definition: Value.h:839
ValueName * getValueName() const
Definition: Value.cpp:190
const User * user_back() const
Definition: Value.h:385
std::unique_ptr< Value, ValueDeleter > unique_value
Use this instead of std::unique_ptr<Value> or std::unique_ptr<Instruction>.
Definition: Value.h:664
static GCRegistry::Add< StatepointGC > D("statepoint-example", "an example strategy for statepoint")
unsigned NumUserOperands
Definition: Value.h:115
ValueTy
Concrete subclass of this.
Definition: Value.h:440
void setValueSubclassData(unsigned short D)
Definition: Value.h:656
bool isUsedByMetadata() const
Return true if there is metadata referencing this value.
Definition: Value.h:484
A range adaptor for a pair of iterators.
const Value * stripAndAccumulateInBoundsConstantOffsets(const DataLayout &DL, APInt &Offset) const
Accumulate offsets from stripInBoundsConstantOffsets().
Definition: Value.cpp:545
Class for arbitrary precision integers.
Definition: APInt.h:69
const_user_iterator user_begin() const
Definition: Value.h:375
iterator_range< user_iterator > users()
Definition: Value.h:395
user_iterator_impl< const User > const_user_iterator
Definition: Value.h:365
could "use" a pointer
void reverseUseList()
Reverse the use-list.
Definition: Value.cpp:699
iterator_range< const_use_iterator > uses() const
Definition: Value.h:354
use_iterator use_begin()
Definition: Value.h:334
bool operator!=(uint64_t V1, const APInt &V2)
Definition: APInt.h:1948
unsigned getNumUses() const
This method computes the number of uses of this Value.
Definition: Value.cpp:164
unsigned HasName
Definition: Value.h:119
LLVMAttributeRef wrap(Attribute Attr)
Definition: Attributes.h:190
static bool doit(const Value &Val)
Definition: Value.h:791
const Value * stripPointerCastsNoFollowAliases() const
Strip off pointer casts and all-zero GEPs.
Definition: Value.cpp:531
StringRef getName() const
Return a constant reference to the value&#39;s name.
Definition: Value.cpp:218
#define I(x, y, z)
Definition: MD5.cpp:58
#define N
user_iterator_impl< User > user_iterator
Definition: Value.h:364
Value * DoPHITranslation(const BasicBlock *CurBB, const BasicBlock *PredBB)
Definition: Value.h:580
static bool doit(const Value &Val)
Definition: Value.h:758
raw_ostream & operator<<(raw_ostream &OS, const APInt &I)
Definition: APInt.h:2018
void mutateType(Type *Ty)
Mutate the type of this Value to be of the specified type.
Definition: Value.h:598
~Value()
Value&#39;s destructor should be virtual by design, but that would require that Value and all of its subc...
Definition: Value.cpp:67
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
user_iterator user_begin()
Definition: Value.h:371
Value * stripAndAccumulateInBoundsConstantOffsets(const DataLayout &DL, APInt &Offset)
Definition: Value.h:542
Base class for aggregate constants (with operands).
Definition: Constants.h:381
LLVM Value Representation.
Definition: Value.h:73
const_user_iterator user_end() const
Definition: Value.h:380
void clearSubclassOptionalData()
Clear the optional flags contained in this value.
Definition: Value.h:471
static bool doit(const Value &Val)
Definition: Value.h:779
Value * stripPointerCastsAndBarriers()
Definition: Value.h:508
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:44
user_iterator materialized_user_begin()
Definition: Value.h:367
void setValueName(ValueName *VN)
Definition: Value.cpp:201
static bool doit(const Value &Val)
Definition: Value.h:833
bool hasOneUse() const
Return true if there is exactly one user of this value.
Definition: Value.h:408
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
static bool doit(const Value &Val)
Definition: Value.h:815
void replaceUsesOutsideBlock(Value *V, BasicBlock *BB)
replaceUsesOutsideBlock - Go through the uses list for this definition and make each use point to "V"...
Definition: Value.cpp:438
bool operator==(uint64_t V1, const APInt &V2)
Definition: APInt.h:1946
const Value * stripInBoundsConstantOffsets() const
Strip off pointer casts and all-constant inbounds GEPs.
Definition: Value.cpp:535
Base class for constants with no operands.
Definition: Constants.h:58
Value * operator=(Value *RHS)
Definition: Value.h:677
bool use_empty() const
Definition: Value.h:322
static bool doit(const Value &Val)
Definition: Value.h:803
struct LLVMOpaqueValue * LLVMValueRef
Represents an individual value in LLVM IR.
Definition: Types.h:76
User * user_back()
Definition: Value.h:381
static bool doit(const Value &Val)
Definition: Value.h:765
user_iterator user_end()
Definition: Value.h:379