LLVM 19.0.0git
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llvm::ConstantPointerNull Class Referencefinal

A constant pointer value that points to null. More...

#include "llvm/IR/Constants.h"

Inheritance diagram for llvm::ConstantPointerNull:
Inheritance graph
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Public Member Functions

 ConstantPointerNull (const ConstantPointerNull &)=delete
 
PointerTypegetType () const
 Specialize the getType() method to always return an PointerType, which reduces the amount of casting needed in parts of the compiler.
 
- Public Member Functions inherited from llvm::ConstantData
void operator delete (void *Ptr)
 
 ConstantData (const ConstantData &)=delete
 
- Public Member Functions inherited from llvm::Constant
void operator= (const Constant &)=delete
 
 Constant (const Constant &)=delete
 
bool isNullValue () const
 Return true if this is the value that would be returned by getNullValue.
 
bool isOneValue () const
 Returns true if the value is one.
 
bool isNotOneValue () const
 Return true if the value is not the one value, or, for vectors, does not contain one value elements.
 
bool isAllOnesValue () const
 Return true if this is the value that would be returned by getAllOnesValue.
 
bool isNegativeZeroValue () const
 Return true if the value is what would be returned by getZeroValueForNegation.
 
bool isZeroValue () const
 Return true if the value is negative zero or null value.
 
bool isNotMinSignedValue () const
 Return true if the value is not the smallest signed value, or, for vectors, does not contain smallest signed value elements.
 
bool isMinSignedValue () const
 Return true if the value is the smallest signed value.
 
bool isFiniteNonZeroFP () const
 Return true if this is a finite and non-zero floating-point scalar constant or a fixed width vector constant with all finite and non-zero elements.
 
bool isNormalFP () const
 Return true if this is a normal (as opposed to denormal, infinity, nan, or zero) floating-point scalar constant or a vector constant with all normal elements.
 
bool hasExactInverseFP () const
 Return true if this scalar has an exact multiplicative inverse or this vector has an exact multiplicative inverse for each element in the vector.
 
bool isNaN () const
 Return true if this is a floating-point NaN constant or a vector floating-point constant with all NaN elements.
 
bool isElementWiseEqual (Value *Y) const
 Return true if this constant and a constant 'Y' are element-wise equal.
 
bool containsUndefOrPoisonElement () const
 Return true if this is a vector constant that includes any undef or poison elements.
 
bool containsPoisonElement () const
 Return true if this is a vector constant that includes any poison elements.
 
bool containsUndefElement () const
 Return true if this is a vector constant that includes any strictly undef (not poison) elements.
 
bool containsConstantExpression () const
 Return true if this is a fixed width vector constant that includes any constant expressions.
 
bool isThreadDependent () const
 Return true if the value can vary between threads.
 
bool isDLLImportDependent () const
 Return true if the value is dependent on a dllimport variable.
 
bool isConstantUsed () const
 Return true if the constant has users other than constant expressions and other dangling things.
 
bool needsRelocation () const
 This method classifies the entry according to whether or not it may generate a relocation entry (either static or dynamic).
 
bool needsDynamicRelocation () const
 
ConstantgetAggregateElement (unsigned Elt) const
 For aggregates (struct/array/vector) return the constant that corresponds to the specified element if possible, or null if not.
 
ConstantgetAggregateElement (Constant *Elt) const
 
ConstantgetSplatValue (bool AllowUndefs=false) const
 If all elements of the vector constant have the same value, return that value.
 
const APIntgetUniqueInteger () const
 If C is a constant integer then return its value, otherwise C must be a vector of constant integers, all equal, and the common value is returned.
 
void destroyConstant ()
 Called if some element of this constant is no longer valid.
 
void handleOperandChange (Value *, Value *)
 This method is a special form of User::replaceUsesOfWith (which does not work on constants) that does work on constants.
 
void removeDeadConstantUsers () const
 If there are any dead constant users dangling off of this constant, remove them.
 
bool hasOneLiveUse () const
 Return true if the constant has exactly one live use.
 
bool hasZeroLiveUses () const
 Return true if the constant has no live uses.
 
const ConstantstripPointerCasts () const
 
ConstantstripPointerCasts ()
 
bool isManifestConstant () const
 Return true if a constant is ConstantData or a ConstantAggregate or ConstantExpr that contain only ConstantData.
 
- Public Member Functions inherited from llvm::User
 User (const User &)=delete
 
void operator delete (void *Usr)
 Free memory allocated for User and Use objects.
 
void operator delete (void *Usr, unsigned)
 Placement delete - required by std, called if the ctor throws.
 
void operator delete (void *Usr, unsigned, unsigned)
 Placement delete - required by std, called if the ctor throws.
 
const UsegetOperandList () const
 
UsegetOperandList ()
 
ValuegetOperand (unsigned i) const
 
void setOperand (unsigned i, Value *Val)
 
const UsegetOperandUse (unsigned i) const
 
UsegetOperandUse (unsigned i)
 
unsigned getNumOperands () const
 
ArrayRef< const uint8_t > getDescriptor () const
 Returns the descriptor co-allocated with this User instance.
 
MutableArrayRef< uint8_t > getDescriptor ()
 Returns the descriptor co-allocated with this User instance.
 
void setGlobalVariableNumOperands (unsigned NumOps)
 Set the number of operands on a GlobalVariable.
 
void setNumHungOffUseOperands (unsigned NumOps)
 Subclasses with hung off uses need to manage the operand count themselves.
 
bool isDroppable () const
 A droppable user is a user for which uses can be dropped without affecting correctness and should be dropped rather than preventing a transformation from happening.
 
op_iterator op_begin ()
 
const_op_iterator op_begin () const
 
op_iterator op_end ()
 
const_op_iterator op_end () const
 
op_range operands ()
 
const_op_range operands () const
 
value_op_iterator value_op_begin ()
 
value_op_iterator value_op_end ()
 
iterator_range< value_op_iteratoroperand_values ()
 
const_value_op_iterator value_op_begin () const
 
const_value_op_iterator value_op_end () const
 
iterator_range< const_value_op_iteratoroperand_values () const
 
void dropAllReferences ()
 Drop all references to operands.
 
bool replaceUsesOfWith (Value *From, Value *To)
 Replace uses of one Value with another.
 
- Public Member Functions inherited from llvm::Value
 Value (const Value &)=delete
 
Valueoperator= (const Value &)=delete
 
void deleteValue ()
 Delete a pointer to a generic Value.
 
void dump () const
 Support for debugging, callable in GDB: V->dump()
 
TypegetType () const
 All values are typed, get the type of this value.
 
LLVMContextgetContext () const
 All values hold a context through their type.
 
bool hasName () const
 
ValueNamegetValueName () const
 
void setValueName (ValueName *VN)
 
StringRef getName () const
 Return a constant reference to the value's name.
 
void setName (const Twine &Name)
 Change the name of the value.
 
void takeName (Value *V)
 Transfer the name from V to this value.
 
std::string getNameOrAsOperand () const
 
void replaceAllUsesWith (Value *V)
 Change all uses of this to point to a new Value.
 
void replaceNonMetadataUsesWith (Value *V)
 Change non-metadata uses of this to point to a new Value.
 
void replaceUsesWithIf (Value *New, llvm::function_ref< bool(Use &U)> ShouldReplace)
 Go through the uses list for this definition and make each use point to "V" if the callback ShouldReplace returns true for the given Use.
 
void replaceUsesOutsideBlock (Value *V, BasicBlock *BB)
 replaceUsesOutsideBlock - Go through the uses list for this definition and make each use point to "V" instead of "this" when the use is outside the block.
 
void assertModuleIsMaterializedImpl () const
 
void assertModuleIsMaterialized () const
 
bool use_empty () const
 
bool materialized_use_empty () const
 
use_iterator materialized_use_begin ()
 
const_use_iterator materialized_use_begin () const
 
use_iterator use_begin ()
 
const_use_iterator use_begin () const
 
use_iterator use_end ()
 
const_use_iterator use_end () const
 
iterator_range< use_iteratormaterialized_uses ()
 
iterator_range< const_use_iteratormaterialized_uses () const
 
iterator_range< use_iteratoruses ()
 
iterator_range< const_use_iteratoruses () const
 
bool user_empty () const
 
user_iterator materialized_user_begin ()
 
const_user_iterator materialized_user_begin () const
 
user_iterator user_begin ()
 
const_user_iterator user_begin () const
 
user_iterator user_end ()
 
const_user_iterator user_end () const
 
Useruser_back ()
 
const Useruser_back () const
 
iterator_range< user_iteratormaterialized_users ()
 
iterator_range< const_user_iteratormaterialized_users () const
 
iterator_range< user_iteratorusers ()
 
iterator_range< const_user_iteratorusers () const
 
bool hasOneUse () const
 Return true if there is exactly one use of this value.
 
bool hasNUses (unsigned N) const
 Return true if this Value has exactly N uses.
 
bool hasNUsesOrMore (unsigned N) const
 Return true if this value has N uses or more.
 
bool hasOneUser () const
 Return true if there is exactly one user of this value.
 
UsegetSingleUndroppableUse ()
 Return true if there is exactly one use of this value that cannot be dropped.
 
const UsegetSingleUndroppableUse () const
 
UsergetUniqueUndroppableUser ()
 Return true if there is exactly one unique user of this value that cannot be dropped (that user can have multiple uses of this value).
 
const UsergetUniqueUndroppableUser () const
 
bool hasNUndroppableUses (unsigned N) const
 Return true if there this value.
 
bool hasNUndroppableUsesOrMore (unsigned N) const
 Return true if this value has N uses or more.
 
void dropDroppableUses (llvm::function_ref< bool(const Use *)> ShouldDrop=[](const Use *) { return true;})
 Remove every uses that can safely be removed.
 
void dropDroppableUsesIn (User &Usr)
 Remove every use of this value in User that can safely be removed.
 
bool isUsedInBasicBlock (const BasicBlock *BB) const
 Check if this value is used in the specified basic block.
 
unsigned getNumUses () const
 This method computes the number of uses of this Value.
 
void addUse (Use &U)
 This method should only be used by the Use class.
 
unsigned getValueID () const
 Return an ID for the concrete type of this object.
 
unsigned getRawSubclassOptionalData () const
 Return the raw optional flags value contained in this value.
 
void clearSubclassOptionalData ()
 Clear the optional flags contained in this value.
 
bool hasSameSubclassOptionalData (const Value *V) const
 Check the optional flags for equality.
 
bool hasValueHandle () const
 Return true if there is a value handle associated with this value.
 
bool isUsedByMetadata () const
 Return true if there is metadata referencing this value.
 
bool isSwiftError () const
 Return true if this value is a swifterror value.
 
const ValuestripPointerCasts () const
 Strip off pointer casts, all-zero GEPs and address space casts.
 
ValuestripPointerCasts ()
 
const ValuestripPointerCastsAndAliases () const
 Strip off pointer casts, all-zero GEPs, address space casts, and aliases.
 
ValuestripPointerCastsAndAliases ()
 
const ValuestripPointerCastsSameRepresentation () const
 Strip off pointer casts, all-zero GEPs and address space casts but ensures the representation of the result stays the same.
 
ValuestripPointerCastsSameRepresentation ()
 
const ValuestripPointerCastsForAliasAnalysis () const
 Strip off pointer casts, all-zero GEPs, single-argument phi nodes and invariant group info.
 
ValuestripPointerCastsForAliasAnalysis ()
 
const ValuestripInBoundsConstantOffsets () const
 Strip off pointer casts and all-constant inbounds GEPs.
 
ValuestripInBoundsConstantOffsets ()
 
const ValuestripAndAccumulateConstantOffsets (const DataLayout &DL, APInt &Offset, bool AllowNonInbounds, bool AllowInvariantGroup=false, function_ref< bool(Value &Value, APInt &Offset)> ExternalAnalysis=nullptr) const
 Accumulate the constant offset this value has compared to a base pointer.
 
ValuestripAndAccumulateConstantOffsets (const DataLayout &DL, APInt &Offset, bool AllowNonInbounds, bool AllowInvariantGroup=false)
 
const ValuestripAndAccumulateInBoundsConstantOffsets (const DataLayout &DL, APInt &Offset) const
 This is a wrapper around stripAndAccumulateConstantOffsets with the in-bounds requirement set to false.
 
ValuestripAndAccumulateInBoundsConstantOffsets (const DataLayout &DL, APInt &Offset)
 
const ValuestripInBoundsOffsets (function_ref< void(const Value *)> Func=[](const Value *) {}) const
 Strip off pointer casts and inbounds GEPs.
 
ValuestripInBoundsOffsets (function_ref< void(const Value *)> Func=[](const Value *) {})
 
std::optional< int64_t > getPointerOffsetFrom (const Value *Other, const DataLayout &DL) const
 If this ptr is provably equal to Other plus a constant offset, return that offset in bytes.
 
bool canBeFreed () const
 Return true if the memory object referred to by V can by freed in the scope for which the SSA value defining the allocation is statically defined.
 
uint64_t getPointerDereferenceableBytes (const DataLayout &DL, bool &CanBeNull, bool &CanBeFreed) const
 Returns the number of bytes known to be dereferenceable for the pointer value.
 
Align getPointerAlignment (const DataLayout &DL) const
 Returns an alignment of the pointer value.
 
const ValueDoPHITranslation (const BasicBlock *CurBB, const BasicBlock *PredBB) const
 Translate PHI node to its predecessor from the given basic block.
 
ValueDoPHITranslation (const BasicBlock *CurBB, const BasicBlock *PredBB)
 
void mutateType (Type *Ty)
 Mutate the type of this Value to be of the specified type.
 
template<class Compare >
void sortUseList (Compare Cmp)
 Sort the use-list.
 
void reverseUseList ()
 Reverse the use-list.
 
void print (raw_ostream &O, bool IsForDebug=false) const
 Implement operator<< on Value.
 
void print (raw_ostream &O, ModuleSlotTracker &MST, bool IsForDebug=false) const
 
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.
 
void printAsOperand (raw_ostream &O, bool PrintType, ModuleSlotTracker &MST) const
 

Static Public Member Functions

static ConstantPointerNullget (PointerType *T)
 Static factory methods - Return objects of the specified value.
 
static bool classof (const Value *V)
 Methods for support type inquiry through isa, cast, and dyn_cast:
 
- Static Public Member Functions inherited from llvm::ConstantData
static bool classof (const Value *V)
 Methods to support type inquiry through isa, cast, and dyn_cast.
 
- Static Public Member Functions inherited from llvm::Constant
static bool classof (const Value *V)
 
static ConstantgetNullValue (Type *Ty)
 Constructor to create a '0' constant of arbitrary type.
 
static ConstantgetAllOnesValue (Type *Ty)
 
static ConstantgetIntegerValue (Type *Ty, const APInt &V)
 Return the value for an integer or pointer constant, or a vector thereof, with the given scalar value.
 
static ConstantreplaceUndefsWith (Constant *C, Constant *Replacement)
 Try to replace undefined constant C or undefined elements in C with Replacement.
 
static ConstantmergeUndefsWith (Constant *C, Constant *Other)
 Merges undefs of a Constant with another Constant, along with the undefs already present.
 
- Static Public Member Functions inherited from llvm::User
static bool classof (const Value *V)
 
- Static Public Member Functions inherited from llvm::Value
static void dropDroppableUse (Use &U)
 Remove the droppable use U.
 

Friends

class Constant
 

Additional Inherited Members

- Public Types inherited from llvm::User
using op_iterator = Use *
 
using const_op_iterator = const Use *
 
using op_range = iterator_range< op_iterator >
 
using const_op_range = iterator_range< const_op_iterator >
 
- Public Types inherited from llvm::Value
enum  ValueTy
 Concrete subclass of this. More...
 
using use_iterator = use_iterator_impl< Use >
 
using const_use_iterator = use_iterator_impl< const Use >
 
using user_iterator = user_iterator_impl< User >
 
using const_user_iterator = user_iterator_impl< const User >
 
- Static Public Attributes inherited from llvm::Value
static constexpr unsigned MaxAlignmentExponent = 32
 The maximum alignment for instructions.
 
static constexpr uint64_t MaximumAlignment = 1ULL << MaxAlignmentExponent
 
- Protected Types inherited from llvm::Value
enum  : unsigned { NumUserOperandsBits = 27 }
 The number of operands in the subclass. More...
 
- Protected Member Functions inherited from llvm::ConstantData
 ConstantData (Type *Ty, ValueTy VT)
 
void * operator new (size_t S)
 
- Protected Member Functions inherited from llvm::Constant
 Constant (Type *ty, ValueTy vty, Use *Ops, unsigned NumOps)
 
 ~Constant ()=default
 
- Protected Member Functions inherited from llvm::User
void * operator new (size_t Size)
 Allocate a User with an operand pointer co-allocated.
 
void * operator new (size_t Size, unsigned Us)
 Allocate a User with the operands co-allocated.
 
void * operator new (size_t Size, unsigned Us, unsigned DescBytes)
 Allocate a User with the operands co-allocated.
 
 User (Type *ty, unsigned vty, Use *, unsigned NumOps)
 
void allocHungoffUses (unsigned N, bool IsPhi=false)
 Allocate the array of Uses, followed by a pointer (with bottom bit set) to the User.
 
void growHungoffUses (unsigned N, bool IsPhi=false)
 Grow the number of hung off uses.
 
 ~User ()=default
 
template<int Idx>
UseOp ()
 
template<int Idx>
const UseOp () const
 
- Protected Member Functions inherited from llvm::Value
 Value (Type *Ty, unsigned scid)
 
 ~Value ()
 Value's destructor should be virtual by design, but that would require that Value and all of its subclasses have a vtable that effectively duplicates the information in the value ID.
 
void getAllMetadata (SmallVectorImpl< std::pair< unsigned, MDNode * > > &MDs) const
 Appends all metadata attached to this value to MDs, sorting by KindID.
 
bool hasMetadata () const
 Return true if this value has any metadata attached to it.
 
bool eraseMetadata (unsigned KindID)
 Erase all metadata attachments with the given kind.
 
void eraseMetadataIf (function_ref< bool(unsigned, MDNode *)> Pred)
 Erase all metadata attachments matching the given predicate.
 
void clearMetadata ()
 Erase all metadata attached to this Value.
 
MDNodegetMetadataImpl (unsigned KindID) const
 Get metadata for the given kind, if any.
 
unsigned short getSubclassDataFromValue () const
 
void setValueSubclassData (unsigned short D)
 
MDNodegetMetadata (unsigned KindID) const
 Get the current metadata attachments for the given kind, if any.
 
MDNodegetMetadata (StringRef Kind) const
 
void getMetadata (unsigned KindID, SmallVectorImpl< MDNode * > &MDs) const
 Appends all attachments with the given ID to MDs in insertion order.
 
void getMetadata (StringRef Kind, SmallVectorImpl< MDNode * > &MDs) const
 
bool hasMetadata (unsigned KindID) const
 Return true if this value has the given type of metadata attached.
 
bool hasMetadata (StringRef Kind) const
 
void setMetadata (unsigned KindID, MDNode *Node)
 Set a particular kind of metadata attachment.
 
void setMetadata (StringRef Kind, MDNode *Node)
 
void addMetadata (unsigned KindID, MDNode &MD)
 Add a metadata attachment.
 
void addMetadata (StringRef Kind, MDNode &MD)
 
- Static Protected Member Functions inherited from llvm::User
template<int Idx, typename U >
static UseOpFrom (const U *that)
 
- Protected Attributes inherited from llvm::Value
unsigned char SubclassOptionalData: 7
 Hold subclass data that can be dropped.
 
unsigned NumUserOperands: NumUserOperandsBits
 
unsigned IsUsedByMD: 1
 
unsigned HasName: 1
 
unsigned HasMetadata: 1
 
unsigned HasHungOffUses: 1
 
unsigned HasDescriptor: 1
 

Detailed Description

A constant pointer value that points to null.

Definition at line 547 of file Constants.h.

Constructor & Destructor Documentation

◆ ConstantPointerNull()

llvm::ConstantPointerNull::ConstantPointerNull ( const ConstantPointerNull )
delete

Member Function Documentation

◆ classof()

static bool llvm::ConstantPointerNull::classof ( const Value V)
inlinestatic

Methods for support type inquiry through isa, cast, and dyn_cast:

Definition at line 568 of file Constants.h.

◆ get()

ConstantPointerNull * ConstantPointerNull::get ( PointerType T)
static

◆ getType()

PointerType * llvm::ConstantPointerNull::getType ( ) const
inline

Specialize the getType() method to always return an PointerType, which reduces the amount of casting needed in parts of the compiler.

Definition at line 563 of file Constants.h.

References llvm::Value::getType().

Referenced by llvm::ObjectSizeOffsetVisitor::visitConstantPointerNull().

Friends And Related Function Documentation

◆ Constant

friend class Constant
friend

Definition at line 548 of file Constants.h.


The documentation for this class was generated from the following files: