This is an important base class in LLVM. More...

#include "llvm/IR/Constant.h"

Inheritance diagram for llvm::Constant:

Public Member Functions
void	operator= (const Constant &)=delete

	Constant (const Constant &)=delete

LLVM_ABI bool	isNullValue () const
	Return true if this is the value that would be returned by getNullValue.

LLVM_ABI bool	isOneValue () const
	Returns true if the value is one.

LLVM_ABI bool	isNotOneValue () const
	Return true if the value is not the one value, or, for vectors, does not contain one value elements.

LLVM_ABI bool	isAllOnesValue () const
	Return true if this is the value that would be returned by getAllOnesValue.

LLVM_ABI bool	isNegativeZeroValue () const
	Return true if the value is what would be returned by getZeroValueForNegation.

LLVM_ABI bool	isZeroValue () const
	Return true if the value is negative zero or null value.

LLVM_ABI bool	isNotMinSignedValue () const
	Return true if the value is not the smallest signed value, or, for vectors, does not contain smallest signed value elements.

LLVM_ABI bool	isMinSignedValue () const
	Return true if the value is the smallest signed value.

LLVM_ABI 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.

LLVM_ABI 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.

LLVM_ABI 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.

LLVM_ABI bool	isNaN () const
	Return true if this is a floating-point NaN constant or a vector floating-point constant with all NaN elements.

LLVM_ABI bool	isElementWiseEqual (Value *Y) const
	Return true if this constant and a constant 'Y' are element-wise equal.

LLVM_ABI bool	containsUndefOrPoisonElement () const
	Return true if this is a vector constant that includes any undef or poison elements.

LLVM_ABI bool	containsPoisonElement () const
	Return true if this is a vector constant that includes any poison elements.

LLVM_ABI bool	containsUndefElement () const
	Return true if this is a vector constant that includes any strictly undef (not poison) elements.

LLVM_ABI bool	containsConstantExpression () const
	Return true if this is a fixed width vector constant that includes any constant expressions.

LLVM_ABI bool	isThreadDependent () const
	Return true if the value can vary between threads.

LLVM_ABI bool	isDLLImportDependent () const
	Return true if the value is dependent on a dllimport variable.

LLVM_ABI bool	isConstantUsed () const
	Return true if the constant has users other than constant expressions and other dangling things.

LLVM_ABI bool	needsRelocation () const
	This method classifies the entry according to whether or not it may generate a relocation entry (either static or dynamic).

LLVM_ABI bool	needsDynamicRelocation () const

LLVM_ABI Constant *	getAggregateElement (unsigned Elt) const
	For aggregates (struct/array/vector) return the constant that corresponds to the specified element if possible, or null if not.

LLVM_ABI Constant *	getAggregateElement (Constant *Elt) const

LLVM_ABI Constant *	getSplatValue (bool AllowPoison=false) const
	If all elements of the vector constant have the same value, return that value.

LLVM_ABI const APInt &	getUniqueInteger () 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.

LLVM_ABI ConstantRange	toConstantRange () const
	Convert constant to an approximate constant range.

LLVM_ABI void	destroyConstant ()
	Called if some element of this constant is no longer valid.

LLVM_ABI void	handleOperandChange (Value , Value )
	This method is a special form of User::replaceUsesOfWith (which does not work on constants) that does work on constants.

LLVM_ABI void	removeDeadConstantUsers () const
	If there are any dead constant users dangling off of this constant, remove them.

LLVM_ABI bool	hasOneLiveUse () const
	Return true if the constant has exactly one live use.

LLVM_ABI bool	hasZeroLiveUses () const
	Return true if the constant has no live uses.

const Constant *	stripPointerCasts () const

Constant *	stripPointerCasts ()

LLVM_ABI 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

LLVM_ABI void	operator delete (void *Usr)
	Free memory allocated for User and Use objects.

void	operator delete (void *Usr, HungOffOperandsAllocMarker)
	Placement delete - required by std, called if the ctor throws.

void	operator delete (void *Usr, IntrusiveOperandsAllocMarker)
	Placement delete - required by std, called if the ctor throws.

void	operator delete (void *Usr, IntrusiveOperandsAndDescriptorAllocMarker)
	Placement delete - required by std, called if the ctor throws.

const Use *	getOperandList () const

Use *	getOperandList ()

Value *	getOperand (unsigned i) const

void	setOperand (unsigned i, Value *Val)

const Use &	getOperandUse (unsigned i) const

Use &	getOperandUse (unsigned i)

unsigned	getNumOperands () const

LLVM_ABI ArrayRef< const uint8_t >	getDescriptor () const
	Returns the descriptor co-allocated with this User instance.

LLVM_ABI MutableArrayRef< uint8_t >	getDescriptor ()
	Returns the descriptor co-allocated with this User instance.

void	setNumHungOffUseOperands (unsigned NumOps)
	Subclasses with hung off uses need to manage the operand count themselves.

LLVM_ABI 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_iterator >	operand_values ()

const_value_op_iterator	value_op_begin () const

const_value_op_iterator	value_op_end () const

iterator_range< const_value_op_iterator >	operand_values () const

void	dropAllReferences ()
	Drop all references to operands.

LLVM_ABI bool	replaceUsesOfWith (Value From, Value To)
	Replace uses of one Value with another.

Public Member Functions inherited from llvm::Value
	Value (const Value &)=delete

Value &	operator= (const Value &)=delete

LLVM_ABI void	deleteValue ()
	Delete a pointer to a generic Value.

LLVM_ABI void	dump () const
	Support for debugging, callable in GDB: V->dump()

Type *	getType () const
	All values are typed, get the type of this value.

LLVM_ABI LLVMContext &	getContext () const
	All values hold a context through their type.

bool	hasName () const

LLVM_ABI ValueName *	getValueName () const

LLVM_ABI void	setValueName (ValueName *VN)

LLVM_ABI StringRef	getName () const
	Return a constant reference to the value's name.

LLVM_ABI void	setName (const Twine &Name)
	Change the name of the value.

LLVM_ABI void	takeName (Value *V)
	Transfer the name from V to this value.

LLVM_ABI std::string	getNameOrAsOperand () const

LLVM_ABI void	replaceAllUsesWith (Value *V)
	Change all uses of this to point to a new Value.

LLVM_ABI void	replaceNonMetadataUsesWith (Value *V)
	Change non-metadata uses of this to point to a new Value.

LLVM_ABI 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.

LLVM_ABI 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.

LLVM_ABI void	assertModuleIsMaterializedImpl () const

void	assertModuleIsMaterialized () const

bool	hasUseList () const
	Check if this Value has a use-list.

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_iterator >	materialized_uses ()

iterator_range< const_use_iterator >	materialized_uses () const

iterator_range< use_iterator >	uses ()

iterator_range< const_use_iterator >	uses () 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

User *	user_back ()

const User *	user_back () const

iterator_range< user_iterator >	materialized_users ()

iterator_range< const_user_iterator >	materialized_users () const

iterator_range< user_iterator >	users ()

iterator_range< const_user_iterator >	users () const

bool	hasOneUse () const
	Return true if there is exactly one use of this value.

LLVM_ABI bool	hasNUses (unsigned N) const
	Return true if this Value has exactly N uses.

LLVM_ABI bool	hasNUsesOrMore (unsigned N) const
	Return true if this value has N uses or more.

LLVM_ABI bool	hasOneUser () const
	Return true if there is exactly one user of this value.

LLVM_ABI Use *	getSingleUndroppableUse ()
	Return true if there is exactly one use of this value that cannot be dropped.

const Use *	getSingleUndroppableUse () const

LLVM_ABI User *	getUniqueUndroppableUser ()
	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 User *	getUniqueUndroppableUser () const

LLVM_ABI bool	hasNUndroppableUses (unsigned N) const
	Return true if there this value.

LLVM_ABI bool	hasNUndroppableUsesOrMore (unsigned N) const
	Return true if this value has N uses or more.

LLVM_ABI void	dropDroppableUses (llvm::function_ref< bool(const Use )> ShouldDrop=[](const Use ) { return true;})
	Remove every uses that can safely be removed.

LLVM_ABI void	dropDroppableUsesIn (User &Usr)
	Remove every use of this value in `User` that can safely be removed.

LLVM_ABI bool	isUsedInBasicBlock (const BasicBlock *BB) const
	Check if this value is used in the specified basic block.

LLVM_ABI 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.

LLVM_ABI bool	isSwiftError () const
	Return true if this value is a swifterror value.

LLVM_ABI const Value *	stripPointerCasts () const
	Strip off pointer casts, all-zero GEPs and address space casts.

Value *	stripPointerCasts ()

LLVM_ABI const Value *	stripPointerCastsAndAliases () const
	Strip off pointer casts, all-zero GEPs, address space casts, and aliases.

Value *	stripPointerCastsAndAliases ()

LLVM_ABI const Value *	stripPointerCastsSameRepresentation () const
	Strip off pointer casts, all-zero GEPs and address space casts but ensures the representation of the result stays the same.

Value *	stripPointerCastsSameRepresentation ()

LLVM_ABI const Value *	stripPointerCastsForAliasAnalysis () const
	Strip off pointer casts, all-zero GEPs, single-argument phi nodes and invariant group info.

Value *	stripPointerCastsForAliasAnalysis ()

LLVM_ABI const Value *	stripInBoundsConstantOffsets () const
	Strip off pointer casts and all-constant inbounds GEPs.

Value *	stripInBoundsConstantOffsets ()

LLVM_ABI const Value *	stripAndAccumulateConstantOffsets (const DataLayout &DL, APInt &Offset, bool AllowNonInbounds, bool AllowInvariantGroup=false, function_ref< bool(Value &Value, APInt &Offset)> ExternalAnalysis=nullptr, bool LookThroughIntToPtr=false) const
	Accumulate the constant offset this value has compared to a base pointer.

Value *	stripAndAccumulateConstantOffsets (const DataLayout &DL, APInt &Offset, bool AllowNonInbounds, bool AllowInvariantGroup=false, function_ref< bool(Value &Value, APInt &Offset)> ExternalAnalysis=nullptr, bool LookThroughIntToPtr=false)

const Value *	stripAndAccumulateInBoundsConstantOffsets (const DataLayout &DL, APInt &Offset) const
	This is a wrapper around stripAndAccumulateConstantOffsets with the in-bounds requirement set to false.

Value *	stripAndAccumulateInBoundsConstantOffsets (const DataLayout &DL, APInt &Offset)

LLVM_ABI const Value *	stripInBoundsOffsets (function_ref< void(const Value )> Func=[](const Value ) {}) const
	Strip off pointer casts and inbounds GEPs.

Value *	stripInBoundsOffsets (function_ref< void(const Value )> Func=[](const Value ) {})

LLVM_ABI 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.

LLVM_ABI 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.

LLVM_ABI uint64_t	getPointerDereferenceableBytes (const DataLayout &DL, bool &CanBeNull, bool &CanBeFreed) const
	Returns the number of bytes known to be dereferenceable for the pointer value.

LLVM_ABI Align	getPointerAlignment (const DataLayout &DL) const
	Returns an alignment of the pointer value.

LLVM_ABI const Value *	DoPHITranslation (const BasicBlock CurBB, const BasicBlock PredBB) const
	Translate PHI node to its predecessor from the given basic block.

Value *	DoPHITranslation (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.

LLVM_ABI void	reverseUseList ()
	Reverse the use-list.

LLVM_ABI void	print (raw_ostream &O, bool IsForDebug=false) const
	Implement operator<< on Value.

LLVM_ABI void	print (raw_ostream &O, ModuleSlotTracker &MST, bool IsForDebug=false) const

LLVM_ABI 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.

LLVM_ABI void	printAsOperand (raw_ostream &O, bool PrintType, ModuleSlotTracker &MST) const

Static Public Member Functions
static bool	classof (const Value *V)

static LLVM_ABI Constant *	getNullValue (Type *Ty)
	Constructor to create a '0' constant of arbitrary type.

static LLVM_ABI Constant *	getAllOnesValue (Type *Ty)

static LLVM_ABI Constant *	getIntegerValue (Type *Ty, const APInt &V)
	Return the value for an integer or pointer constant, or a vector thereof, with the given scalar value.

static LLVM_ABI Constant *	replaceUndefsWith (Constant C, Constant Replacement)
	Try to replace undefined constant C or undefined elements in C with Replacement.

static LLVM_ABI Constant *	mergeUndefsWith (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 LLVM_ABI void	dropDroppableUse (Use &U)
	Remove the droppable use `U`.

Protected Member Functions
	Constant (Type *ty, ValueTy vty, AllocInfo AllocInfo)

	~Constant ()=default

Protected Member Functions inherited from llvm::User
void *	operator new (size_t Size)=delete

LLVM_ABI void *	operator new (size_t Size, HungOffOperandsAllocMarker)
	Allocate a User with an operand pointer co-allocated.

LLVM_ABI void *	operator new (size_t Size, IntrusiveOperandsAllocMarker allocTrait)
	Allocate a User with the operands co-allocated.

LLVM_ABI void *	operator new (size_t Size, IntrusiveOperandsAndDescriptorAllocMarker allocTrait)
	Allocate a User with the operands co-allocated.

	User (Type *ty, unsigned vty, AllocInfo AllocInfo)

LLVM_ABI void	allocHungoffUses (unsigned N, bool IsPhi=false)
	Allocate the array of Uses, followed by a pointer (with bottom bit set) to the User.

LLVM_ABI void	growHungoffUses (unsigned N, bool IsPhi=false)
	Grow the number of hung off uses.

	~User ()=default

template<int Idx>
Use &	Op ()

template<int Idx>
const Use &	Op () const

Protected Member Functions inherited from llvm::Value
LLVM_ABI	Value (Type *Ty, unsigned scid)

LLVM_ABI	~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.

LLVM_ABI 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.

LLVM_ABI bool	eraseMetadata (unsigned KindID)
	Erase all metadata attachments with the given kind.

LLVM_ABI void	eraseMetadataIf (function_ref< bool(unsigned, MDNode *)> Pred)
	Erase all metadata attachments matching the given predicate.

LLVM_ABI void	clearMetadata ()
	Erase all metadata attached to this Value.

LLVM_ABI MDNode *	getMetadataImpl (unsigned KindID) const
	Get metadata for the given kind, if any.

unsigned short	getSubclassDataFromValue () const

void	setValueSubclassData (unsigned short D)

MDNode *	getMetadata (unsigned KindID) const
	Get the current metadata attachments for the given kind, if any.

LLVM_ABI MDNode *	getMetadata (StringRef Kind) const

LLVM_ABI void	getMetadata (unsigned KindID, SmallVectorImpl< MDNode * > &MDs) const
	Appends all attachments with the given ID to `MDs` in insertion order.

LLVM_ABI 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

LLVM_ABI void	setMetadata (unsigned KindID, MDNode *Node)
	Set a particular kind of metadata attachment.

LLVM_ABI void	setMetadata (StringRef Kind, MDNode *Node)

LLVM_ABI void	addMetadata (unsigned KindID, MDNode &MD)
	Add a metadata attachment.

LLVM_ABI void	addMetadata (StringRef Kind, MDNode &MD)

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...

Static Protected Member Functions inherited from llvm::User
template<int Idx, typename U >
static Use &	OpFrom (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

This is an important base class in LLVM.

It provides the common facilities of all constant values in an LLVM program. A constant is a value that is immutable at runtime. Functions are constants because their address is immutable. Same with global variables.

All constants share the capabilities provided in this class. All constants can have a null value. They can have an operand list. Constants can be simple (integer and floating point values), complex (arrays and structures), or expression based (computations yielding a constant value composed of only certain operators and other constant values).

Note that Constants are immutable (once created they never change) and are fully shared by structural equivalence. This means that two structurally equivalent constants will always have the same address. Constants are created on demand as needed and never deleted: thus clients don't have to worry about the lifetime of the objects. LLVM Constant Representation

Definition at line 43 of file Constant.h.

Constructor & Destructor Documentation

◆ Constant() [1/2]

llvm::Constant::Constant	(	Type *	ty,
		ValueTy	vty,
		AllocInfo	AllocInfo
	)

inlineprotected

Definition at line 45 of file Constant.h.

◆ ~Constant()

llvm::Constant::~Constant ( )

protecteddefault

◆ Constant() [2/2]

llvm::Constant::Constant ( const Constant & )

delete

Member Function Documentation

◆ classof()

static bool llvm::Constant::classof ( const Value * V )

inlinestatic

Definition at line 173 of file Constant.h.

◆ containsConstantExpression()

bool Constant::containsConstantExpression ( ) const

Return true if this is a fixed width vector constant that includes any constant expressions.

Definition at line 360 of file Constants.cpp.

References getAggregateElement(), and llvm::Value::getType().

◆ containsPoisonElement()

bool Constant::containsPoisonElement ( ) const

Return true if this is a vector constant that includes any poison elements.

Definition at line 349 of file Constants.cpp.

References llvm::CallingConv::C, and containsUndefinedElement().

◆ containsUndefElement()

bool Constant::containsUndefElement ( ) const

Return true if this is a vector constant that includes any strictly undef (not poison) elements.

Definition at line 354 of file Constants.cpp.

References llvm::CallingConv::C, and containsUndefinedElement().

◆ containsUndefOrPoisonElement()

bool Constant::containsUndefOrPoisonElement ( ) const

Return true if this is a vector constant that includes any undef or poison elements.

Since it is impossible to inspect a scalable vector element- wise at compile time, this function returns true only if the entire vector is undef or poison.

Definition at line 344 of file Constants.cpp.

References llvm::CallingConv::C, and containsUndefinedElement().

◆ destroyConstant()

void Constant::destroyConstant ( )

Called if some element of this constant is no longer valid.

At this point only other constants may be on the use_list for this constant. Any constants on our Use list must also be destroy'd. The implementation must be sure to remove the constant from the list of available cached constants. Implementations should implement destroyConstantImpl to remove constants from any pools/maps they are contained it.

First call destroyConstantImpl on the subclass. This gives the subclass a chance to remove the constant from any maps/pools it's contained in.

Definition at line 489 of file Constants.cpp.

References assert(), llvm::dbgs(), llvm::deleteConstant(), llvm::Value::getValueID(), llvm_unreachable, llvm::Value::use_empty(), and llvm::Value::user_back().

Referenced by handleOperandChange(), llvm::MergeBasicBlockIntoOnlyPred(), and processBlockAddr().

◆ getAggregateElement() [1/2]

Constant * Constant::getAggregateElement ( Constant * Elt ) const

Definition at line 478 of file Constants.cpp.

References assert(), getAggregateElement(), and llvm::Value::getType().

◆ getAggregateElement() [2/2]

Constant * Constant::getAggregateElement ( unsigned Elt ) const

For aggregates (struct/array/vector) return the constant that corresponds to the specified element if possible, or null if not.

This can return null if the element index is a ConstantExpr, if 'this' is a constant expr or if the constant does not fit into an uint64_t.

Definition at line 435 of file Constants.cpp.

References assert(), llvm::Value::getContext(), and llvm::Value::getType().

Referenced by areInverseVectorBitmasks(), CheckAndCreateOffsetAdd(), checkOffsetSize(), llvm::InstCombinerImpl::commonIDivRemTransforms(), computeKnownBits(), llvm::SelectionDAG::computeKnownBits(), computeKnownFPClass(), llvm::SelectionDAG::ComputeNumSignBits(), llvm::ConstantFoldExtractElementInstruction(), llvm::ConstantFoldExtractValueInstruction(), llvm::ConstantFoldInsertValueInstruction(), containsConstantExpression(), emitGlobalConstantVector(), llvm::FlushFPConstant(), foldConstantInsEltIntoShuffle(), getAggregateElement(), getGapMask(), getSplatableConstant(), getTargetConstantBitsFromNode(), getUniqueInteger(), hasExactInverseFP(), isFiniteNonZeroFP(), isKnownIntegral(), isNaN(), isNormalFP(), isNotMinSignedValue(), isNotOneValue(), matchStridedConstant(), matchSubIntegerPackFromVector(), llvm::InstCombinerImpl::SimplifyDemandedVectorElts(), simplifySelectInst(), and WriteConstantInternal().

◆ getAllOnesValue()

Constant * Constant::getAllOnesValue ( Type * Ty )

static

Returns: the value for an integer or vector of integer constant of the given type that has all its bits set to true. Get the all ones value

Definition at line 420 of file Constants.cpp.

References llvm::APInt::getAllOnes(), llvm::APFloat::getAllOnesValue(), getAllOnesValue(), llvm::Type::getContext(), llvm::VectorType::getElementCount(), llvm::VectorType::getElementType(), llvm::Type::getFltSemantics(), llvm::ConstantVector::getSplat(), and llvm::Type::isFloatingPointTy().

◆ getIntegerValue()

Constant * Constant::getIntegerValue	(	Type *	Ty,
		const APInt &	V
	)

static

Return the value for an integer or pointer constant, or a vector thereof, with the given scalar value.

Definition at line 403 of file Constants.cpp.

References llvm::CallingConv::C, llvm::Type::getContext(), llvm::ConstantExpr::getIntToPtr(), llvm::Type::getScalarType(), and llvm::ConstantVector::getSplat().

Referenced by constantFoldUser(), createIRLevelProfileFlagVar(), createMemprofHistogramFlagVar(), llvm::createProfileSamplingVar(), llvm::AtomicInfo::EmitAtomicCompareExchangeLibcall(), llvm::InstCombinerImpl::foldBinOpOfSelectAndCastOfSelectCondition(), foldCtpopPow2Test(), llvm::InstCombinerImpl::foldICmpBinOp(), llvm::InstCombinerImpl::foldICmpUsingKnownBits(), foldSwitchToSelect(), llvm::dxil::ResourceInfo::getAsMetadata(), getConstantVector(), llvm::ConstantExpr::getIntrinsicIdentity(), llvm::MinMaxIntrinsic::getSaturationPoint(), llvm::InstCombinerImpl::SimplifyDemandedUseBits(), llvm::InstCombinerImpl::SimplifyMultipleUseDemandedBits(), simplifyX86pack(), and llvm::InstCombinerImpl::visitCallInst().

◆ getNullValue()

Constant * Constant::getNullValue ( Type * Ty )

static

Constructor to create a '0' constant of arbitrary type.

Definition at line 373 of file Constants.cpp.

References llvm::Type::ArrayTyID, llvm::Type::BFloatTyID, llvm::Type::DoubleTyID, llvm::Type::FixedVectorTyID, llvm::Type::FloatTyID, llvm::Type::FP128TyID, llvm::ConstantTokenNone::get(), llvm::ConstantPointerNull::get(), llvm::ConstantTargetNone::get(), llvm::ConstantAggregateZero::get(), llvm::Type::getContext(), llvm::Type::getFltSemantics(), llvm::Type::getTypeID(), llvm::APFloat::getZero(), llvm::Type::HalfTyID, llvm::Type::IntegerTyID, llvm_unreachable, llvm::Type::PointerTyID, llvm::Type::PPC_FP128TyID, llvm::Type::ScalableVectorTyID, llvm::Type::StructTyID, llvm::Type::TargetExtTyID, llvm::Type::TokenTyID, and llvm::Type::X86_FP80TyID.

◆ getSplatValue()

Constant * Constant::getSplatValue ( bool AllowPoison = false ) const

If all elements of the vector constant have the same value, return that value.

Otherwise, return nullptr. Ignore poison elements by setting AllowPoison to true.

Definition at line 1713 of file Constants.cpp.

References llvm::all_of(), assert(), llvm::PoisonValue::get(), llvm::Value::getContext(), getNullValue(), llvm::User::getOperand(), llvm::Value::getType(), and I.

Referenced by llvm::SelectionDAG::computeKnownBits(), computeKnownBitsFromOperator(), llvm::ConstantFoldBinaryInstruction(), llvm::ConstantFoldCompareInstruction(), llvm::ConstantFoldExtractElementInstruction(), llvm::FlushFPConstant(), getUniqueInteger(), hasExactInverseFP(), isAllOnesValue(), isFiniteNonZeroFP(), isMinSignedValue(), isNaN(), isNegativeZeroValue(), isNormalFP(), isNotMinSignedValue(), isNotOneValue(), isOneValue(), isZeroValue(), toConstantRange(), and WriteConstantInternal().

◆ getUniqueInteger()

const APInt & Constant::getUniqueInteger ( ) 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.

Definition at line 1778 of file Constants.cpp.

References assert(), llvm::CallingConv::C, getAggregateElement(), and getSplatValue().

Referenced by foldShiftIntoShiftInAnotherHandOfAndInICmp().

◆ handleOperandChange()

void Constant::handleOperandChange	(	Value *	From,
		Value *	To
	)

This method is a special form of User::replaceUsesOfWith (which does not work on constants) that does work on constants.

Update this constant array to change uses of 'From' to be uses of 'To'.

Basically this method goes through the trouble of building a new constant that is equivalent to the current one, with all uses of From replaced with uses of To. After this construction is completed, all of the users of 'this' are replaced to use the new constant, and then 'this' is deleted. In general, you should not call this method, instead, use Value::replaceAllUsesWith, which automatically dispatches to this method as needed.

This must update the uniquing data structures etc.

Note that we intentionally replace all uses of From with To here. Consider a large array that uses 'From' 1000 times. By handling this case all here, ConstantArray::handleOperandChange is only invoked once, and that single invocation handles all 1000 uses. Handling them one at a time would work, but would be really slow because it would have to unique each updated array instance.

Definition at line 3261 of file Constants.cpp.

References assert(), destroyConstant(), llvm::Value::getValueID(), llvm_unreachable, and llvm::Value::replaceAllUsesWith().

◆ hasExactInverseFP()

bool Constant::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.

Definition at line 256 of file Constants.cpp.

References getAggregateElement(), getSplatValue(), llvm::Value::getType(), and I.

◆ hasOneLiveUse()

bool Constant::hasOneLiveUse ( ) const

Return true if the constant has exactly one live use.

This returns the same result as calling Value::hasOneUse after Constant::removeDeadConstantUsers, but doesn't remove dead constants.

Definition at line 766 of file Constants.cpp.

◆ hasZeroLiveUses()

bool Constant::hasZeroLiveUses ( ) const

Return true if the constant has no live uses.

This returns the same result as calling Value::use_empty after Constant::removeDeadConstantUsers, but doesn't remove dead constants.

Definition at line 768 of file Constants.cpp.

◆ isAllOnesValue()

bool Constant::isAllOnesValue ( ) const

Return true if this is the value that would be returned by getAllOnesValue.

Definition at line 107 of file Constants.cpp.

References getSplatValue(), and llvm::Value::getType().

Referenced by simplifyICmpInst().

◆ isConstantUsed()

bool Constant::isConstantUsed ( ) const

Return true if the constant has users other than constant expressions and other dangling things.

Definition at line 639 of file Constants.cpp.

References isConstantUsed(), and llvm::Value::users().

Referenced by findPartitions(), and isConstantUsed().

◆ isDLLImportDependent()

bool Constant::isDLLImportDependent ( ) const

Return true if the value is dependent on a dllimport variable.

Definition at line 632 of file Constants.cpp.

References ConstHasGlobalValuePredicate().

◆ isElementWiseEqual()

bool Constant::isElementWiseEqual ( Value * Y ) const

Return true if this constant and a constant 'Y' are element-wise equal.

This is identical to just comparing the pointers, with the exception that for vectors, if only one of the constants has an undef element in some lane, the constants still match.

Definition at line 298 of file Constants.cpp.

References llvm::ConstantFoldCompareInstruction(), llvm::ConstantExpr::getBitCast(), llvm::VectorType::getInteger(), llvm::Value::getType(), llvm::CmpInst::ICMP_EQ, llvm::PatternMatch::m_One(), llvm::PatternMatch::match(), and Y.

Referenced by llvm::InstCombinerImpl::visitSExt(), and llvm::InstCombinerImpl::visitSub().

◆ isFiniteNonZeroFP()

bool Constant::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.

Definition at line 214 of file Constants.cpp.

References getAggregateElement(), getSplatValue(), llvm::Value::getType(), and I.

◆ isManifestConstant()

bool Constant::isManifestConstant ( ) const

Return true if a constant is ConstantData or a ConstantAggregate or ConstantExpr that contain only ConstantData.

Definition at line 843 of file Constants.cpp.

References isManifestConstant(), and llvm::User::operand_values().

Referenced by isManifestConstant().

◆ isMinSignedValue()

bool Constant::isMinSignedValue ( ) const

Return true if the value is the smallest signed value.

Definition at line 169 of file Constants.cpp.

References getSplatValue(), and llvm::Value::getType().

◆ isNaN()

bool Constant::isNaN ( ) const

Return true if this is a floating-point NaN constant or a vector floating-point constant with all NaN elements.

Definition at line 277 of file Constants.cpp.

References getAggregateElement(), getSplatValue(), llvm::Value::getType(), and I.

Referenced by propagateNaN().

◆ isNegativeZeroValue()

bool Constant::isNegativeZeroValue ( ) const

Return true if the value is what would be returned by getZeroValueForNegation.

Definition at line 56 of file Constants.cpp.

References getSplatValue(), llvm::Value::getType(), and isNullValue().

◆ isNormalFP()

bool Constant::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.

See APFloat::isNormal.

Definition at line 235 of file Constants.cpp.

References getAggregateElement(), getSplatValue(), llvm::Value::getType(), and I.

Referenced by foldFDivConstantDividend(), and llvm::InstCombinerImpl::foldFMulReassoc().

◆ isNotMinSignedValue()

bool Constant::isNotMinSignedValue ( ) const

Return true if the value is not the smallest signed value, or, for vectors, does not contain smallest signed value elements.

Definition at line 186 of file Constants.cpp.

References getAggregateElement(), getSplatValue(), llvm::Value::getType(), I, and isNotMinSignedValue().

Referenced by isNotMinSignedValue(), and llvm::InstCombinerImpl::visitMul().

◆ isNotOneValue()

bool Constant::isNotOneValue ( ) const

Return true if the value is not the one value, or, for vectors, does not contain one value elements.

Definition at line 141 of file Constants.cpp.

References getAggregateElement(), getSplatValue(), llvm::Value::getType(), I, and isNotOneValue().

Referenced by isNotOneValue().

◆ isNullValue()

bool Constant::isNullValue ( ) const

Return true if this is the value that would be returned by getNullValue.

Definition at line 90 of file Constants.cpp.

Referenced by addConditions(), addTryBlockMapEntry(), calculateSEHStateNumbers(), llvm::InstCombinerImpl::commonIDivRemTransforms(), llvm::ConstantFoldCompareInstOperands(), llvm::ConstantFoldCompareInstruction(), llvm::ConstantFoldGetElementPtr(), llvm::ConstantFoldInsertElementInstruction(), llvm::ConstantFoldShuffleVectorInstruction(), llvm::InstCombinerImpl::foldICmpInstWithConstantNotInt(), foldShiftIntoShiftInAnotherHandOfAndInICmp(), foldSwitchToSelect(), llvm::getConstantDataArrayInfo(), getPredicateResult(), llvm::inferAttribute(), llvm::GCNTTIImpl::instCombineIntrinsic(), isCatchAll(), llvm::ConstantPtrAuth::isKnownCompatibleWith(), isKnownNonZero(), isNegativeZeroValue(), isZeroValue(), llvm::AsmPrinter::lowerConstant(), optimizeOnceStoredGlobal(), runImpl(), shouldUseSwitchConditionAsTableIndex(), llvm::InstCombinerImpl::SimplifyDemandedVectorElts(), simplifyICmpInst(), and TryToShrinkGlobalToBoolean().

◆ isOneValue()

bool Constant::isOneValue ( ) const

Returns true if the value is one.

Definition at line 124 of file Constants.cpp.

References getSplatValue(), and llvm::Value::getType().

Referenced by findBestNonTrivialUnswitchCandidate(), llvm::InstCombinerImpl::SimplifyDemandedVectorElts(), and unswitchNontrivialInvariants().

◆ isThreadDependent()

bool Constant::isThreadDependent ( ) const

Return true if the value can vary between threads.

Definition at line 625 of file Constants.cpp.

References ConstHasGlobalValuePredicate().

◆ isZeroValue()

bool Constant::isZeroValue ( ) const

Return true if the value is negative zero or null value.

Definition at line 76 of file Constants.cpp.

References getSplatValue(), llvm::Value::getType(), and isNullValue().

Referenced by computeKnownBitsFromOperator(), expandVecReduceAdd(), shouldConvertImpl(), and llvm::InstCombinerImpl::visitXor().

◆ mergeUndefsWith()

Constant * Constant::mergeUndefsWith	(	Constant *	C,
		Constant *	Other
	)

static

Merges undefs of a Constant with another Constant, along with the undefs already present.

Other doesn't have to be the same type as C, but both must either be scalars or vectors with the same element count. If no changes are made, the constant C is returned.

Definition at line 808 of file Constants.cpp.

References assert(), llvm::CallingConv::C, llvm::ConstantVector::get(), llvm::UndefValue::get(), I, llvm::PatternMatch::m_Undef(), llvm::PatternMatch::match(), and llvm::Other.

Referenced by llvm::InstCombinerImpl::convertOrOfShiftsToFunnelShift(), foldSelectZeroOrFixedOp(), llvm::InstCombinerImpl::visitAShr(), llvm::InstCombinerImpl::visitSExt(), llvm::InstCombinerImpl::visitTrunc(), and llvm::InstCombinerImpl::visitXor().

◆ needsDynamicRelocation()

bool Constant::needsDynamicRelocation ( ) const

Definition at line 651 of file Constants.cpp.

◆ needsRelocation()

bool Constant::needsRelocation ( ) const

This method classifies the entry according to whether or not it may generate a relocation entry (either static or dynamic).

This must be conservative, so if it might codegen to a relocatable entry, it should say so.

FIXME: This really should not be in IR.

Definition at line 655 of file Constants.cpp.

◆ operator=()

void llvm::Constant::operator= ( const Constant & )

delete

◆ removeDeadConstantUsers()

void Constant::removeDeadConstantUsers ( ) const

If there are any dead constant users dangling off of this constant, remove them.

This method is useful for clients that want to check to see if a global is unused, but don't want to deal with potentially dead constants hanging off of the globals.

Definition at line 739 of file Constants.cpp.

References constantIsDead(), I, llvm::Value::user_begin(), and llvm::Value::user_end().

Referenced by CleanupConstantGlobalUsers(), CleanupPointerRootUsers(), deleteIfDead(), hasAddressTakenAndUsed(), mustPreserveGV(), llvm::CallGraphUpdater::replaceFunctionWith(), llvm::GlobalDCEPass::run(), SRAGlobal(), and llvm::GlobalValue::~GlobalValue().

◆ replaceUndefsWith()

Constant * Constant::replaceUndefsWith	(	Constant *	C,
		Constant *	Replacement
	)

static

Try to replace undefined constant C or undefined elements in C with Replacement.

If no changes are made, the constant C is returned.

Definition at line 784 of file Constants.cpp.

References assert(), llvm::CallingConv::C, llvm::ConstantVector::get(), llvm::Value::getType(), llvm::PatternMatch::m_Undef(), and llvm::PatternMatch::match().

Referenced by dropRedundantMaskingOfLeftShiftInput(), llvm::getFlippedStrictnessPredicateAndConstant(), llvm::InstCombinerImpl::visitFreeze(), visitMaskedMerge(), and llvm::InstCombinerImpl::visitXor().

◆ stripPointerCasts() [1/2]

Constant * llvm::Constant::stripPointerCasts ( )

inline

Definition at line 223 of file Constant.h.

References stripPointerCasts().

◆ stripPointerCasts() [2/2]

const Constant * llvm::Constant::stripPointerCasts ( ) const

inline

Definition at line 219 of file Constant.h.

References llvm::Value::stripPointerCasts().

Referenced by addTryBlockMapEntry(), llvm::CanInlineCallSite(), llvm::AsmPrinter::emitGlobalAlias(), llvm::ARMAsmPrinter::emitXXStructor(), hasUsesToReplace(), llvm::InlineFunctionImpl(), OptimizeGlobalAliases(), runImpl(), stripPointerCasts(), and llvm::InstCombinerImpl::visitLandingPadInst().

◆ toConstantRange()

ConstantRange Constant::toConstantRange ( ) const

Convert constant to an approximate constant range.

For vectors, the range is the union over the element ranges. Poison elements are ignored.

Definition at line 1792 of file Constants.cpp.

References llvm::BitWidth, llvm::User::getOperand(), llvm::Type::getScalarSizeInBits(), getSplatValue(), llvm::Value::getType(), I, and llvm::ConstantRange::unionWith().

Referenced by llvm::ValueLatticeElement::asConstantRange(), and llvm::ValueLatticeElement::mergeIn().

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

include/llvm/IR/Constant.h
lib/IR/Constants.cpp

Public Member Functions

Static Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Constant() [1/2]

◆ ~Constant()

◆ Constant() [2/2]

Member Function Documentation

◆ classof()

◆ containsConstantExpression()

◆ containsPoisonElement()

◆ containsUndefElement()

◆ containsUndefOrPoisonElement()

◆ destroyConstant()

◆ getAggregateElement() [1/2]

◆ getAggregateElement() [2/2]

◆ getAllOnesValue()

◆ getIntegerValue()

◆ getNullValue()

◆ getSplatValue()

◆ getUniqueInteger()

◆ handleOperandChange()

◆ hasExactInverseFP()

◆ hasOneLiveUse()

◆ hasZeroLiveUses()

◆ isAllOnesValue()

◆ isConstantUsed()

◆ isDLLImportDependent()

◆ isElementWiseEqual()

◆ isFiniteNonZeroFP()

◆ isManifestConstant()

◆ isMinSignedValue()

◆ isNaN()

◆ isNegativeZeroValue()

◆ isNormalFP()

◆ isNotMinSignedValue()

◆ isNotOneValue()

◆ isNullValue()

◆ isOneValue()

◆ isThreadDependent()

◆ isZeroValue()

◆ mergeUndefsWith()

◆ needsDynamicRelocation()

◆ needsRelocation()

◆ operator=()

◆ removeDeadConstantUsers()

◆ replaceUndefsWith()

◆ stripPointerCasts() [1/2]

◆ stripPointerCasts() [2/2]

◆ toConstantRange()