com.oracle.svm.core.snippets

Class KnownIntrinsics

java.lang.Object

com.oracle.svm.core.snippets.KnownIntrinsics

public class KnownIntrinsics
extends Object

Functions that are implemented as compiler intrinsics. For implementation see SubstrateGraphBuilderPlugins.registerKnownIntrinsicsPlugins().

Constructor Summary

Constructors

Constructor and Description
KnownIntrinsics()

Method Summary

Modifier and Type	Method and Description
static <T> T	convertUnknownValue(Object obj, Class<T> type) This method is a helper for the static analysis.
static void	farReturn(Object result, org.graalvm.word.Pointer sp, org.graalvm.nativeimage.c.function.CodePointer ip, boolean fromMethodWithCalleeSavedRegisters) Continues execution in the specified caller frame, at the specified instruction pointer.
static org.graalvm.word.Pointer	heapBase() Returns the value of the heap base.
static boolean	isDeoptimizationTarget() For deoptimization testing only.
static org.graalvm.word.Pointer	nonNullPointer(org.graalvm.word.Pointer pointer) Narrow down the range of values to exclude 0 as the possible pointer value.
static int	readArrayLength(Object array) Returns the length of the given array.
static org.graalvm.word.Pointer	readCallerStackPointer() Returns the value of the native stack pointer for the physical caller frame.
static DynamicHub	readHub(Object obj) Returns the hub of the given object.
static org.graalvm.nativeimage.c.function.CodePointer	readReturnAddress() Returns the value of the native instruction pointer for the physical caller frame.
static org.graalvm.word.Pointer	readStackPointer() Returns the value of the native stack pointer.
static void	testDeoptimize() For deoptimization testing only.

Methods inherited from class java.lang.Object

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

Constructor Detail

KnownIntrinsics

public KnownIntrinsics()

Method Detail

heapBase

public static org.graalvm.word.Pointer heapBase()

Returns the value of the heap base.

readArrayLength

public static int readArrayLength(Object array)

Returns the length of the given array. It does not check if the provided object is an array, so the caller has to check that beforehand.

readHub

public static DynamicHub readHub(Object obj)

Returns the hub of the given object.

nonNullPointer

public static org.graalvm.word.Pointer nonNullPointer(org.graalvm.word.Pointer pointer)

Narrow down the range of values to exclude 0 as the possible pointer value.

Parameters:

pointer - that we are narrowing to non-null

Returns:

a pointer with stamp non-null

readStackPointer

public static org.graalvm.word.Pointer readStackPointer()

Returns the value of the native stack pointer.

readCallerStackPointer

public static org.graalvm.word.Pointer readCallerStackPointer()

Returns the value of the native stack pointer for the physical caller frame. The caller of this method must be annotated with NeverInline to ensure that the physical caller frame is deterministic.

readReturnAddress

public static org.graalvm.nativeimage.c.function.CodePointer readReturnAddress()

Returns the value of the native instruction pointer for the physical caller frame. The caller of this method must be annotated with NeverInline to ensure that the physical caller frame is deterministic.

farReturn

public static void farReturn(Object result,
                             org.graalvm.word.Pointer sp,
                             org.graalvm.nativeimage.c.function.CodePointer ip,
                             boolean fromMethodWithCalleeSavedRegisters)

Continues execution in the specified caller frame, at the specified instruction pointer. The result is placed in the register used for object results, simulating the return from a method with an Object return type. Note that this is very dangerous. You have to know what you are doing. The parameters are not checked for correctness in any way.

testDeoptimize

public static void testDeoptimize()

For deoptimization testing only. Performs a deoptimization in a regular method, but is a no-op in a deoptimization target method.

isDeoptimizationTarget

public static boolean isDeoptimizationTarget()

For deoptimization testing only. Folds to true in a deoptimization target method and to false in a deoptimization source method.

convertUnknownValue

public static <T> T convertUnknownValue(Object obj,
                                        Class<T> type)

This method is a helper for the static analysis. It converts objects that have an unknown value, e.g., objects that resulted from a low level memory read, i.e., word-to-object reads, into proper objects. By default during analysis all objects that result from low level reads are treated as having unknown value. We only convert them to proper objects when they are used as a receiver object in calls, loads, stores, etc. Thus, objects that are never used as proper Java objects, but only passed around as data, e.g., in the GC, will not interfere with the points-to analysis. If an unknown value object is used as a proper object, for example as a receiver for a call, an unsupported feature will be reported. The type parameter will reduce the type of the return value from the all instantiated types to the type subtree of the specified type. If Object.class is specified no actual type reduction is done. The method has a default implementation which just returns the obj parameter because it can used in places that are reached at runtime (hence analyzed) but also during image building (e.g., SharedConstantReflectionProvider.unboxPrimitive(JavaConstant)). For the analysis case a call to it is intercepted in SubstrateGraphBuilderPlugins.registerKnownIntrinsicsPlugins() and replaced with a ConvertUnknownValueNode which later is processed during analysis type flow graph building.