org.graalvm.compiler.core.common

Class StrideUtil

java.lang.Object

org.graalvm.compiler.core.common.StrideUtil

public final class StrideUtil
extends Object

This class provides utility methods for "stride-agnostic" intrinsic nodes such as org.graalvm.compiler.replacements.nodes.ArrayRegionCompareToNode. These intrinsics may work with fixed strides of 1, 2 or 4 bytes per element, or with a dynamic parameter containing the stride in log2 format, i.e. 0 -> 1 byte, 1 -> 2 byte, 2 -> 4 byte. If an intrinsic method has two array parameters with potentially different strides, both log2 stride values are encoded into one as follows: (strideA * N_STRIDES) + strideB. This value is used inside the intrinsic as a jump table index to dispatch to separately compiled versions for each possible combination of strides.

Field Summary

Fields

Modifier and Type	Field and Description
static int	N_STRIDES Number of possible values of a single stride parameter.
static JavaKind	NONE Alias for intrinsics that take a JavaKind parameter to declare the type of an array parameter.
static JavaKind	S1 Short aliases for intrinsics that take JavaKind parameters to describe a stride in bytes.
static JavaKind	S2
static JavaKind	S4

Constructor Summary

Constructors

Constructor and Description
StrideUtil()

Method Summary

Modifier and Type	Method and Description
static JavaKind	getConstantStrideA(int directStubCallIndex) Extract strideA from directStubCallIndex.
static JavaKind	getConstantStrideB(int directStubCallIndex) Extract strideB from directStubCallIndex.
static int	getDirectStubCallIndex(int log2StrideA, int log2StrideB) Encode the given stride values into one direct stub call index.
static int	log2(JavaKind stride) Get the given stride's log2 form.
static JavaKind	log2ToStride(int log2Stride) Convert the given log2 stride value to a JavaKind value.
static boolean	useConstantStrides(Value dynamicStride) Returns true if the dynamicStride parameter is unused, which implies constant strides must be used instead.

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

N_STRIDES

public static final int N_STRIDES

Number of possible values of a single stride parameter. Currently, possible values are 0, 1, and 2.

See Also:

Constant Field Values

S1

public static final JavaKind S1

Short aliases for intrinsics that take JavaKind parameters to describe a stride in bytes. The naming is "S" for "stride", followed by the stride width in bytes.

S2

public static final JavaKind S2

S4

public static final JavaKind S4

NONE

public static final JavaKind NONE

Alias for intrinsics that take a JavaKind parameter to declare the type of an array parameter. This parameter "NONE" means that the array type is unknown or a native buffer has been used instead.

Constructor Detail

StrideUtil

public StrideUtil()

Method Detail

getConstantStrideA

public static JavaKind getConstantStrideA(int directStubCallIndex)

Extract strideA from directStubCallIndex.

getConstantStrideB

public static JavaKind getConstantStrideB(int directStubCallIndex)

Extract strideB from directStubCallIndex.

getDirectStubCallIndex

public static int getDirectStubCallIndex(int log2StrideA,
                                         int log2StrideB)

Encode the given stride values into one direct stub call index.

log2

public static int log2(JavaKind stride)

Get the given stride's log2 form.

log2ToStride

public static JavaKind log2ToStride(int log2Stride)

Convert the given log2 stride value to a JavaKind value.

useConstantStrides

public static boolean useConstantStrides(Value dynamicStride)

Returns true if the dynamicStride parameter is unused, which implies constant strides must be used instead.