org.graalvm.compiler.core.common

Class LIRKind

java.lang.Object

<any>

org.graalvm.compiler.core.common.LIRKind

public final class LIRKind
extends <any>

Represents the type of values in the LIR. It is composed of a PlatformKind that gives the low level representation of the value, a LIRKind.referenceMask that describes the location of object references in the value, a LIRKind.referenceCompressionMask that indicates which of these references are compressed references, and for derived references a LIRKind.derivedReferenceBase.

Constructing LIRKind instances

During LIR generation, every new Value should get a LIRKind of the correct PlatformKind that also contains the correct reference information. LIRKinds should be created as follows:

If the result value is created from one or more input values, the LIRKind should be created with LIRKind.combine(Value...)(inputs). If the result has a different PlatformKind than the inputs, LIRKind.combine(Value...)(inputs).LIRKind.changeType(PlatformKind)(resultKind) should be used.

If the result is an exact copy of one of the inputs, Value.getValueKind() or LIRKind.mergeReferenceInformation(Value...)can be used. Note that this is only correct for move-like operations, like conditional move or compare-and-swap. For convert operations, LIRKind.combine(Value...) should be used.

If it is known that the result will be a reference (e.g. pointer arithmetic where the end result is a valid oop), LIRKind.reference(PlatformKind) or LIRKind.compressedReference(PlatformKind) should be used.

If it is known that the result will neither be a reference nor be derived from a reference, LIRKind.value(PlatformKind) can be used. If the operation producing this value has inputs, this is very likely wrong, and LIRKind.combine(Value...) should be used instead.

If it is known that the result is derived from a reference in a way that the garbage collector can not track, LIRKind.unknownReference(PlatformKind) can be used. In most cases, LIRKind.combine(Value...) should be used instead, since it is able to detect this automatically.

Field Summary

Fields

Modifier and Type	Field and Description
static LIRKind	Illegal

Method Summary

Modifier and Type	Method and Description
LIRKind	changeType(PlatformKind newPlatformKind) Create a new LIRKind with the same reference information and a new platform kind.
static LIRKind	combine(Value... inputs) Derive a new type from inputs.
static LIRKind	combineDerived(LIRKind kind, AllocatableValue base1, AllocatableValue base2) Helper method to construct derived reference kinds.
static LIRKind	compressedReference(PlatformKind platformKind) Create a LIRKind of type platformKind that contains a single, tracked, compressed oop reference.
static AllocatableValue	derivedBaseFromValue(AllocatableValue value) Helper method to construct derived reference kinds.
static LIRKind	derivedReference(PlatformKind platformKind, AllocatableValue base, boolean compressed) Create a LIRKind of type platformKind that contains a derived reference.
boolean	equals(Object obj)
static LIRKind	fromJavaKind(Architecture arch, JavaKind javaKind) Create the correct LIRKind for a given Architecture and JavaKind.
AllocatableValue	getDerivedReferenceBase() Get the base value of a derived reference.
int	getReferenceCount()
int	hashCode()
boolean	isCompressedReference(int idx) Check whether the idxth part of this value is a compressed reference.
boolean	isDerivedReference() Check whether this value is a derived reference.
boolean	isReference(int idx) Check whether the idxth part of this value is a reference that must be tracked at safepoints.
boolean	isUnknownReference() Check whether this value is derived from a reference in a non-linear way.
static boolean	isUnknownReference(<any> kind)
static boolean	isUnknownReference(Value value)
boolean	isValue() Check whether this kind is a value type that doesn't need to be tracked at safepoints.
static boolean	isValue(<any> kind)
static boolean	isValue(Value value)
LIRKind	makeDerivedReference(AllocatableValue base) Create a derived reference.
LIRKind	makeUnknownReference() Create a new LIRKind with the same type, but marked as containing an LIRKind.unknownReference(PlatformKind).
static LIRKind	mergeReferenceInformation(LIRKind mergeKind, LIRKind inputKind) Merges the reference information of the inputs.
static LIRKind	mergeReferenceInformation(Value... inputs) Merges the reference information of the inputs.
static LIRKind	reference(PlatformKind platformKind) Create a LIRKind of type platformKind that contains a single, tracked, uncompressed oop reference.
LIRKind	repeat(PlatformKind newPlatformKind) Create a new LIRKind with a new platform kind.
void	setDerivedReferenceBase(AllocatableValue derivedReferenceBase) Change the base value of a derived reference.
String	toString()
static LIRKind	unknownReference(PlatformKind platformKind) Create a LIRKind of type platformKind that contains a value that is derived from a reference in a non-linear way.
static LIRKind	value(PlatformKind platformKind) Create a LIRKind of type platformKind that contains a primitive value.
static boolean	verifyMoveKinds(<any> dst, <any> src, RegisterAllocationConfig config)

Methods inherited from class java.lang.Object

clone, getClass, notify, notifyAll, wait, wait, wait

Field Detail

Illegal

public static final LIRKind Illegal

Method Detail

value

public static LIRKind value(PlatformKind platformKind)

Create a LIRKind of type platformKind that contains a primitive value. Should be only used when it's guaranteed that the value is not even indirectly derived from a reference. Otherwise, LIRKind.combine(Value...) should be used instead.

reference

public static LIRKind reference(PlatformKind platformKind)

Create a LIRKind of type platformKind that contains a single, tracked, uncompressed oop reference.

compressedReference

public static LIRKind compressedReference(PlatformKind platformKind)

Create a LIRKind of type platformKind that contains a single, tracked, compressed oop reference.

fromJavaKind

public static LIRKind fromJavaKind(Architecture arch,
                                   JavaKind javaKind)

Create the correct LIRKind for a given Architecture and JavaKind.

derivedReference

public static LIRKind derivedReference(PlatformKind platformKind,
                                       AllocatableValue base,
                                       boolean compressed)

Create a LIRKind of type platformKind that contains a derived reference.

unknownReference

public static LIRKind unknownReference(PlatformKind platformKind)

Create a LIRKind of type platformKind that contains a value that is derived from a reference in a non-linear way. Values of this LIRKind can not be live at safepoints. In most cases, this should not be called directly. LIRKind.combine(Value...) should be used instead to automatically propagate this information.

makeDerivedReference

public LIRKind makeDerivedReference(AllocatableValue base)

Create a derived reference.

Parameters:

base - An AllocatableValue containing the base pointer of the derived reference.

combine

public static LIRKind combine(Value... inputs)

Derive a new type from inputs. The result will have the PlatformKind of one of the inputs. If all inputs are values, the result is a value. Otherwise, the result is an unknown reference. This method should be used to construct the result LIRKind of any operation that modifies values (e.g. arithmetics).

derivedBaseFromValue

public static AllocatableValue derivedBaseFromValue(AllocatableValue value)

Helper method to construct derived reference kinds. Returns the base value of a reference or derived reference. For values it returns null, and for unknown references it returns Value.ILLEGAL.

combineDerived

public static LIRKind combineDerived(LIRKind kind,
                                     AllocatableValue base1,
                                     AllocatableValue base2)

Helper method to construct derived reference kinds. If one of base1 or base2 are set, it creates a derived reference using it as the base. If both are set, the result is an unknown reference.

mergeReferenceInformation

public static LIRKind mergeReferenceInformation(Value... inputs)

Merges the reference information of the inputs. The result will have the PlatformKind of inputs[0]. If all inputs are values (references), the result is a value (reference). Otherwise, the result is an unknown reference. The correctness of the PlatformKind is not verified.

mergeReferenceInformation

public static LIRKind mergeReferenceInformation(LIRKind mergeKind,
                                                LIRKind inputKind)

Merges the reference information of the inputs. The result will have the PlatformKind of mergeKind. If all inputs are values (references), the result is a value (reference). Otherwise, the result is an unknown reference. The correctness of the PlatformKind is not verified.

changeType

public LIRKind changeType(PlatformKind newPlatformKind)

Create a new LIRKind with the same reference information and a new platform kind. If the new kind is a longer vector than this, the new elements are marked as untracked values.

repeat

public LIRKind repeat(PlatformKind newPlatformKind)

Create a new LIRKind with a new platform kind. If the new kind is longer than this, the reference positions are repeated to fill the vector.

makeUnknownReference

public LIRKind makeUnknownReference()

Create a new LIRKind with the same type, but marked as containing an LIRKind.unknownReference(PlatformKind).

isDerivedReference

public boolean isDerivedReference()

Check whether this value is a derived reference.

getDerivedReferenceBase

public AllocatableValue getDerivedReferenceBase()

Get the base value of a derived reference.

setDerivedReferenceBase

public void setDerivedReferenceBase(AllocatableValue derivedReferenceBase)

Change the base value of a derived reference. This must be called on derived references only.

isUnknownReference

public boolean isUnknownReference()

Check whether this value is derived from a reference in a non-linear way. If this returns true, this value must not be live at safepoints.

isUnknownReference

public static boolean isUnknownReference(<any> kind)

isUnknownReference

public static boolean isUnknownReference(Value value)

getReferenceCount

public int getReferenceCount()

isReference

public boolean isReference(int idx)

Check whether the idxth part of this value is a reference that must be tracked at safepoints.

Parameters:

idx - The index into the vector if this is a vector kind. Must be 0 if this is a scalar kind.

isCompressedReference

public boolean isCompressedReference(int idx)

Check whether the idxth part of this value is a compressed reference.

Parameters:

idx - The index into the vector if this is a vector kind. Must be 0 if this is a scalar kind.

isValue

public boolean isValue()

Check whether this kind is a value type that doesn't need to be tracked at safepoints.

isValue

public static boolean isValue(<any> kind)

isValue

public static boolean isValue(Value value)

toString

public String toString()

hashCode

public int hashCode()

equals

public boolean equals(Object obj)

verifyMoveKinds

public static boolean verifyMoveKinds(<any> dst,
                                      <any> src,
                                      RegisterAllocationConfig config)