Module jdk.incubator.vector

Package jdk.incubator.vector

Interface VectorSpecies<E>

Type Parameters:

E - the boxed version of ETYPE, the element type of a vector

public interface VectorSpecies<E>

Interface for managing all vectors of the same combination of element type (ETYPE) and shape.

API Note:

User code should not implement this interface. A future release of this type may restrict implementations to be members of the same package.

Implementation Note:

The string representation of an instance of this interface will be of the form "Species[ETYPE, VLENGTH, SHAPE]", where ETYPE is the primitive lane type, VLENGTH is the vector lane count associated with the species, and SHAPE is the vector shape associated with the species.

Vector species objects can be stored in locals and parameters and as static final constants, but storing them in other Java fields or in array elements, while semantically valid, may incur performance penalties.

Method Summary

Modifier and Type	Method	Description
Vector<E>	broadcast(long e)	Returns a vector of the given species where all lane elements are set to the primitive value e.
<F> VectorSpecies<F>	check(Class<F> elementType)	Checks that this species has the given element type, and returns this species unchanged.
long	checkValue(long e)	Checks that this species can represent the given element value, and returns the value unchanged.
int	elementSize()	Returns the lane size, in bits, of vectors of this species.
static int	elementSize(Class<?> elementType)	Returns the bit-size of the given vector element type (ETYPE).
Class<E>	elementType()	Returns the primitive element type of vectors of this species.
boolean	equals(Object obj)	Indicates whether this species is identical to some other object.
Vector<E>	fromArray(Object a, int offset)	Returns a vector of this species where lane elements are initialized from the given array at the given offset.
Vector<E>	fromMemorySegment(MemorySegment ms, long offset, ByteOrder bo)	Loads a vector of this species from a memory segment starting at an offset into the memory segment.
int	hashCode()	Returns a hash code value for the species, based on the vector shape and element type.
VectorMask<E>	indexInRange(int offset, int limit)	Returns a mask of this species where only the lanes at index N such that the adjusted index N+offset is in the range [0..limit-1] are set.
VectorMask<E>	indexInRange(long offset, long limit)	Returns a mask of this species where only the lanes at index N such that the adjusted index N+offset is in the range [0..limit-1] are set.
VectorShuffle<E>	iotaShuffle(int start, int step, boolean wrap)	Creates a shuffle using source indexes set to sequential values starting from start and stepping by the given step.
int	length()	Returns the number of lanes in a vector of this species.
VectorMask<E>	loadMask(boolean[] bits, int offset)	Returns a mask of this species where lane elements are initialized from the given array at the given offset.
int	loopBound(int length)	Loop control function which returns the largest multiple of VLENGTH that is less than or equal to the given length value.
long	loopBound(long length)	Loop control function which returns the largest multiple of VLENGTH that is less than or equal to the given length value.
VectorMask<E>	maskAll(boolean bit)	Returns a mask of this species, where each lane is set or unset according to given single boolean, which is broadcast to all lanes.
Class<? extends VectorMask<E>>	maskType()	Returns the vector mask type for this species.
static <E> VectorSpecies<E>	of(Class<E> elementType, VectorShape shape)	Finds a species for an element type and shape.
static <E> VectorSpecies<E>	ofLargestShape(Class<E> etype)	Finds the largest vector species of the given element type.
static <E> VectorSpecies<E>	ofPreferred(Class<E> etype)	Finds the species preferred by the current platform for a given vector element type.
int	partLimit(VectorSpecies<?> outputSpecies, boolean lanewise)	Given this species and a second one, reports the net expansion or contraction of a (potentially) resizing reinterpretation cast or lane-wise conversion from this species to the second.
VectorShuffle<E>	shuffleFromArray(int[] sourceIndexes, int offset)	Creates a shuffle for this species from an int array starting at an offset.
VectorShuffle<E>	shuffleFromOp(IntUnaryOperator fn)	Creates a shuffle for this species from the successive values of an operator applied to the range [0..VLENGTH-1].
VectorShuffle<E>	shuffleFromValues(int... sourceIndexes)	Creates a shuffle for this species from a series of source indexes.
String	toString()	Returns a string of the form "Species[ETYPE, VLENGTH, SHAPE]", where ETYPE is the primitive lane type, VLENGTH is the vector lane count associated with the species, and SHAPE is the vector shape associated with the species.
int	vectorBitSize()	Returns the total vector size, in bits, of any vector of this species.
int	vectorByteSize()	Returns the total vector size, in bytes, of any vector of this species.
VectorShape	vectorShape()	Returns the shape of vectors produced by this species.
Class<? extends Vector<E>>	vectorType()	Returns the vector type of this species.
<F> VectorSpecies<F>	withLanes(Class<F> newType)	Finds a species with the given element type and the same shape as this species.
VectorSpecies<E>	withShape(VectorShape newShape)	Finds a species with the given shape and the same elementType as this species.
Vector<E>	zero()	Returns a vector of this species where all lane elements are set to the default primitive value, (ETYPE)0.

Method Details

elementType

Class<E> elementType()

Returns the primitive element type of vectors of this species.

Returns:

the primitive element type (ETYPE)

See Also:

• Class.arrayType()

vectorType

Class<? extends Vector<E>> vectorType()

Returns the vector type of this species. A vector is of this species if and only if it is of the corresponding vector type.

Returns:

the vector type of this species

maskType

Class<? extends VectorMask<E>> maskType()

Returns the vector mask type for this species.

Returns:

the mask type

elementSize

int elementSize()

Returns the lane size, in bits, of vectors of this species.

Returns:

the element size, in bits

vectorShape

VectorShape vectorShape()

Returns the shape of vectors produced by this species.

Returns:

the shape of any vectors of this species

length

int length()

Returns the number of lanes in a vector of this species.

API Note:

This is also the number of lanes in a mask or shuffle associated with a vector of this species.

Returns:

the number of vector lanes

vectorBitSize

int vectorBitSize()

Returns the total vector size, in bits, of any vector of this species. This is the same value as this.vectorShape().vectorBitSize().

API Note:

This size may be distinct from the size in bits of a mask or shuffle of this species.

Returns:

the total vector size, in bits

vectorByteSize

int vectorByteSize()

Returns the total vector size, in bytes, of any vector of this species. This is the same value as this.vectorShape().vectorBitSize() / Byte.SIZE.

API Note:

This size may be distinct from the size in bits of a mask or shuffle of this species.

Returns:

the total vector size, in bytes

loopBound

int loopBound(int length)

Loop control function which returns the largest multiple of VLENGTH that is less than or equal to the given length value. Here, VLENGTH is the result of this.length(), and length is interpreted as a number of lanes. The resulting value R satisfies this inequality:

R <= length < R+VLENGTH
 

Specifically, this method computes length - floorMod(length, VLENGTH), where floorMod computes a remainder value by rounding its quotient toward negative infinity. As long as VLENGTH is a power of two, then the result is also equal to length & ~(VLENGTH - 1).

Parameters:

length - the input length

Returns:

the largest multiple of the vector length not greater than the given length

Throws:

IllegalArgumentException - if the length is negative and the result would overflow to a positive value

See Also:

• Math.floorMod(int, int)

loopBound

long loopBound(long length)

Loop control function which returns the largest multiple of VLENGTH that is less than or equal to the given length value. Here, VLENGTH is the result of this.length(), and length is interpreted as a number of lanes. The resulting value R satisfies this inequality:

R <= length < R+VLENGTH
 

Specifically, this method computes length - floorMod(length, VLENGTH), where floorMod computes a remainder value by rounding its quotient toward negative infinity. As long as VLENGTH is a power of two, then the result is also equal to length & ~(VLENGTH - 1).

Parameters:

length - the input length

Returns:

the largest multiple of the vector length not greater than the given length

Throws:

IllegalArgumentException - if the length is negative and the result would overflow to a positive value

Since:

19

See Also:

• Math.floorMod(long, int)

indexInRange

VectorMask<E> indexInRange(int offset,
 int limit)

Returns a mask of this species where only the lanes at index N such that the adjusted index N+offset is in the range [0..limit-1] are set.

This method returns the value of the expression maskAll(true).indexInRange(offset, limit)

Parameters:

offset - the starting index

limit - the upper-bound (exclusive) of index range

Returns:

a mask with out-of-range lanes unset

See Also:

• VectorMask.indexInRange(int, int)

indexInRange

VectorMask<E> indexInRange(long offset,
 long limit)

Returns a mask of this species where only the lanes at index N such that the adjusted index N+offset is in the range [0..limit-1] are set.

This method returns the value of the expression maskAll(true).indexInRange(offset, limit)

Parameters:

offset - the starting index

limit - the upper-bound (exclusive) of index range

Returns:

a mask with out-of-range lanes unset

Since:

19

See Also:

• VectorMask.indexInRange(long, long)

check

<F> VectorSpecies<F> check(Class<F> elementType)

Checks that this species has the given element type, and returns this species unchanged. The effect is similar to this pseudocode: elementType == elementType() ? this : throw new ClassCastException().

Type Parameters:

F - the boxed element type of the required lane type

Parameters:

elementType - the required lane type

Returns:

the same species

Throws:

ClassCastException - if the species has the wrong element type

See Also:

• Vector.check(Class)
• Vector.check(VectorSpecies)

partLimit

int partLimit(VectorSpecies<?> outputSpecies,
 boolean lanewise)

Given this species and a second one, reports the net expansion or contraction of a (potentially) resizing reinterpretation cast or lane-wise conversion from this species to the second. The sign and magnitude of the return value depends on the size difference between the proposed input and output shapes, and (optionally, if lanewise is true) also on the size difference between the proposed input and output lanes.

• First, a logical result size is determined. If lanewise is false, this size that of the input VSHAPE. If lanewise is true, the logical result size is the product of the input VLENGTH times the size of the output ETYPE.
• Next, the logical result size is compared against the size of the proposed output shape, to see how it will fit.
• If the logical result fits precisely in the output shape, the return value is zero, signifying no net expansion or contraction.
• If the logical result would overflow the output shape, the return value is the ratio (greater than one) of the logical result size to the (smaller) output size. This ratio can be viewed as measuring the proportion of "dropped input bits" which must be deleted from the input in order for the result to fit in the output vector. It is also the part limit, a upper exclusive limit on the part parameter to a method that would transform the input species to the output species.
• If the logical result would drop into the output shape with room to spare, the return value is a negative number whose absolute value the ratio (greater than one) between the output size and the (smaller) logical result size. This ratio can be viewed as measuring the proportion of "extra padding bits" which must be added to the logical result to fill up the output vector. It is also the part limit, an exclusive lower limit on the part parameter to a method that would transform the input species to the output species.

Parameters:

outputSpecies - the proposed output species

lanewise - whether to take lane sizes into account

Returns:

an indication of the size change, as a signed ratio or zero

See Also:

• Vector.reinterpretShape(VectorSpecies,int)
• Vector.convertShape(VectorOperators.Conversion,VectorSpecies,int)

withLanes

<F> VectorSpecies<F> withLanes(Class<F> newType)

Finds a species with the given element type and the same shape as this species. Returns the same value as VectorSpecies.of(newType, this.vectorShape()).

Type Parameters:

F - the boxed element type

Parameters:

newType - the new element type

Returns:

a species for the new element type and the same shape

Throws:

IllegalArgumentException - if no such species exists for the given combination of element type and shape or if the given type is not a valid ETYPE

See Also:

• withShape(VectorShape)
• of(Class, VectorShape)

withShape

VectorSpecies<E> withShape(VectorShape newShape)

Finds a species with the given shape and the same elementType as this species. Returns the same value as VectorSpecies.of(this.elementType(), newShape).

Parameters:

newShape - the new shape

Returns:

a species for the same element type and the new shape

Throws:

IllegalArgumentException - if no such species exists for the given combination of element type and shape

See Also:

• withLanes(Class)
• of(Class, VectorShape)

of

static <E> VectorSpecies<E> of(Class<E> elementType,
 VectorShape shape)

Finds a species for an element type and shape.

Type Parameters:

E - the boxed element type

Parameters:

elementType - the element type

shape - the shape

Returns:

a species for the given element type and shape

Throws:

IllegalArgumentException - if no such species exists for the given combination of element type and shape or if the given type is not a valid ETYPE

See Also:

• withLanes(Class)
• withShape(VectorShape)

ofLargestShape

static <E> VectorSpecies<E> ofLargestShape(Class<E> etype)

Finds the largest vector species of the given element type.

The returned species is a species chosen by the platform that has a shape with the largest possible bit-size for the given element type. The underlying vector shape might not support other lane types on some platforms, which may limit the applicability of reinterpretation casts. Vector algorithms which require reinterpretation casts will be more portable if they use the platform's preferred species.

Type Parameters:

E - the boxed element type

Parameters:

etype - the element type

Returns:

a preferred species for an element type

Throws:

IllegalArgumentException - if no such species exists for the element type or if the given type is not a valid ETYPE

See Also:

• ofPreferred(Class)

ofPreferred

static <E> VectorSpecies<E> ofPreferred(Class<E> etype)

Finds the species preferred by the current platform for a given vector element type. This is the same value as VectorSpecies.of(etype, VectorShape.preferredShape()).

This species is chosen by the platform so that it has the largest possible shape that supports all lane element types. This has the following implications:

• The various preferred species for different element types will have the same underlying shape.
• All vectors created from preferred species will have a common bit-size and information capacity.
• Reinterpretation casts between vectors of preferred species will neither truncate lanes nor fill them with default values.
• For any particular element type, some platform might possibly provide a larger vector shape that (as a trade-off) does not support all possible element types.

Implementation Note:

On many platforms there is no behavioral difference between ofLargestShape and ofPreferred, because the preferred shape is usually also the largest available shape for every lane type. Therefore, most vector algorithms will perform well without ofLargestShape.

Type Parameters:

E - the boxed element type

Parameters:

etype - the element type

Returns:

a preferred species for this element type

Throws:

IllegalArgumentException - if no such species exists for the element type or if the given type is not a valid ETYPE

See Also:

• Vector.reinterpretShape(VectorSpecies,int)
• VectorShape.preferredShape()
• ofLargestShape(Class)

elementSize

static int elementSize(Class<?> elementType)

Returns the bit-size of the given vector element type (ETYPE). The element type must be a valid ETYPE, not a wrapper type or other object type. The element type argument must be a mirror for a valid vector ETYPE, such as byte.class, int.class, or double.class. The bit-size of such a type is the SIZE constant for the corresponding wrapper class, such as Byte.SIZE, or Integer.SIZE, or Double.SIZE.

Parameters:

elementType - a vector element type (an ETYPE)

Returns:

the bit-size of elementType, such as 32 for int.class

Throws:

IllegalArgumentException - if the given elementType argument is not a valid vector ETYPE

zero

Vector<E> zero()

Returns a vector of this species where all lane elements are set to the default primitive value, (ETYPE)0. Equivalent to IntVector.zero(this) or an equivalent zero method, on the vector type corresponding to this species.

Returns:

a zero vector of the given species

See Also:

• IntVector.zero(VectorSpecies)
• FloatVector.zero(VectorSpecies)

fromArray

Vector<E> fromArray(Object a,
 int offset)

Returns a vector of this species where lane elements are initialized from the given array at the given offset. The array must be of the correct ETYPE. Equivalent to IntVector.fromArray(this,a,offset) or an equivalent fromArray method, on the vector type corresponding to this species.

Parameters:

a - an array of the ETYPE for this species

offset - the index of the first lane value to load

Returns:

a vector of the given species filled from the array

Throws:

IndexOutOfBoundsException - if offset+N < 0 or offset+N >= a.length for any lane N in the vector

See Also:

• IntVector.fromArray(VectorSpecies,int[],int)
• FloatVector.fromArray(VectorSpecies,float[],int)

fromMemorySegment

Vector<E> fromMemorySegment(MemorySegment ms,
 long offset,
 ByteOrder bo)

Loads a vector of this species from a memory segment starting at an offset into the memory segment. Bytes are composed into primitive lane elements according to the specified byte order. The vector is arranged into lanes according to memory ordering.

Equivalent to IntVector.fromMemorySegment(this,ms,offset,bo), on the vector type corresponding to this species.

Parameters:

ms - the memory segment

offset - the offset into the memory segment

bo - the intended byte order

Returns:

a vector of the given species filled from the memory segment

Throws:

IndexOutOfBoundsException - if offset+N*ESIZE < 0 or offset+(N+1)*ESIZE > a.length for any lane N in the vector

Since:

19

See Also:

• IntVector.fromMemorySegment(VectorSpecies, java.lang.foreign.MemorySegment, long, java.nio.ByteOrder)
• FloatVector.fromMemorySegment(VectorSpecies, java.lang.foreign.MemorySegment, long, java.nio.ByteOrder)

loadMask

VectorMask<E> loadMask(boolean[] bits,
 int offset)

Returns a mask of this species where lane elements are initialized from the given array at the given offset. Equivalent to VectorMask.fromArray(this,a,offset).

Parameters:

bits - the boolean array

offset - the offset into the array

Returns:

the mask loaded from the boolean array

Throws:

IndexOutOfBoundsException - if offset+N < 0 or offset+N >= a.length for any lane N in the vector mask

See Also:

• VectorMask.fromArray(VectorSpecies,boolean[],int)

maskAll

VectorMask<E> maskAll(boolean bit)

Returns a mask of this species, where each lane is set or unset according to given single boolean, which is broadcast to all lanes.

Parameters:

bit - the given mask bit to be replicated

Returns:

a mask where each lane is set or unset according to the given bit

See Also:

• Vector.maskAll(boolean)

broadcast

Vector<E> broadcast(long e)

Returns a vector of the given species where all lane elements are set to the primitive value e.

This method returns the value of this expression: EVector.broadcast(this, (ETYPE)e), where EVector is the vector class specific to the the ETYPE of this species. The long value must be accurately representable by ETYPE, so that e==(long)(ETYPE)e.

Parameters:

e - the value to broadcast

Returns:

a vector where all lane elements are set to the primitive value e

Throws:

IllegalArgumentException - if the given long value cannot be represented by the vector species ETYPE

See Also:

• Vector.broadcast(long)
• checkValue(long)

checkValue

long checkValue(long e)

Checks that this species can represent the given element value, and returns the value unchanged. The long value must be accurately representable by the ETYPE of the vector species, so that e==(long)(ETYPE)e. The effect is similar to this pseudocode: e == (long)(ETYPE)e ? e : throw new IllegalArgumentException().

Parameters:

e - the value to be checked

Returns:

e

Throws:

IllegalArgumentException - if the given long value cannot be represented by the vector species ETYPE

See Also:

• broadcast(long)

shuffleFromValues

VectorShuffle<E> shuffleFromValues(int... sourceIndexes)

Creates a shuffle for this species from a series of source indexes.

For each shuffle lane, where N is the shuffle lane index, the Nth index value is validated against the species VLENGTH, and (if invalid) is partially wrapped to an exceptional index in the range [-VLENGTH..-1].

Parameters:

sourceIndexes - the source indexes which the shuffle will draw from

Returns:

a shuffle where each lane's source index is set to the given int value, partially wrapped if exceptional

Throws:

IndexOutOfBoundsException - if sourceIndexes.length != VLENGTH

See Also:

• VectorShuffle.fromValues(VectorSpecies,int...)

shuffleFromArray

VectorShuffle<E> shuffleFromArray(int[] sourceIndexes,
 int offset)

Creates a shuffle for this species from an int array starting at an offset.

For each shuffle lane, where N is the shuffle lane index, the array element at index i + N is validated against the species VLENGTH, and (if invalid) is partially wrapped to an exceptional index in the range [-VLENGTH..-1].

Parameters:

sourceIndexes - the source indexes which the shuffle will draw from

offset - the offset into the array

Returns:

a shuffle where each lane's source index is set to the given int value, partially wrapped if exceptional

Throws:

IndexOutOfBoundsException - if offset < 0, or offset > sourceIndexes.length - VLENGTH

See Also:

• VectorShuffle.fromArray(VectorSpecies,int[],int)

shuffleFromOp

VectorShuffle<E> shuffleFromOp(IntUnaryOperator fn)

Creates a shuffle for this species from the successive values of an operator applied to the range [0..VLENGTH-1].

For each shuffle lane, where N is the shuffle lane index, the Nth index value is validated against the species VLENGTH, and (if invalid) is partially wrapped to an exceptional index in the range [-VLENGTH..-1].

Care should be taken to ensure VectorShuffle values produced from this method are consumed as constants to ensure optimal generation of code. For example, shuffle values can be held in static final fields or loop-invariant local variables.

This method behaves as if a shuffle is created from an array of mapped indexes as follows:

   int[] a = new int[VLENGTH];
   for (int i = 0; i < a.length; i++) {
       a[i] = fn.applyAsInt(i);
   }
   return VectorShuffle.fromArray(this, a, 0);
 

Parameters:

fn - the lane index mapping function

Returns:

a shuffle of mapped indexes

See Also:

• VectorShuffle.fromOp(VectorSpecies,IntUnaryOperator)

iotaShuffle

VectorShuffle<E> iotaShuffle(int start,
 int step,
 boolean wrap)

Creates a shuffle using source indexes set to sequential values starting from start and stepping by the given step.

This method returns the value of the expression VectorSpecies.shuffleFromOp(i -> R(start + i * step)), where R is wrapIndex if wrap is true, and is the identity function otherwise.

If wrap is false each index is validated against the species VLENGTH, and (if invalid) is partially wrapped to an exceptional index in the range [-VLENGTH..-1]. Otherwise, if wrap is true, also reduce each index, as if by wrapIndex, to the valid range [0..VLENGTH-1].

API Note:

The wrap parameter should be set to true if invalid source indexes should be wrapped. Otherwise, setting it to false allows invalid source indexes to be range-checked by later operations such as unary rearrange.

Parameters:

start - the starting value of the source index sequence, typically 0

step - the difference between adjacent source indexes, typically 1

wrap - whether to wrap resulting indexes modulo VLENGTH

Returns:

a shuffle of sequential lane indexes

See Also:

• VectorShuffle.iota(VectorSpecies,int,int,boolean)

toString

String toString()

Returns a string of the form "Species[ETYPE, VLENGTH, SHAPE]", where ETYPE is the primitive lane type, VLENGTH is the vector lane count associated with the species, and SHAPE is the vector shape associated with the species.

Overrides:

toString in class Object

Returns:

a string of the form "Species[ETYPE, VLENGTH, SHAPE]"

equals

boolean equals(Object obj)

Indicates whether this species is identical to some other object. Two species are identical only if they have the same shape and same element type.

Overrides:

equals in class Object

Parameters:

obj - the reference object with which to compare.

Returns:

whether this species is identical to some other object

See Also:

• Object.hashCode()
• HashMap

hashCode

int hashCode()

Returns a hash code value for the species, based on the vector shape and element type.

Overrides:

hashCode in class Object

Returns:

a hash code value for this species

See Also:

• Object.equals(java.lang.Object)
• System.identityHashCode(java.lang.Object)