Annotation Interface GenerateUncached

@Retention(CLASS)
@Target(TYPE)
public @interface GenerateUncached

Generates an uncached version of a node with specializations. Uncached versions of nodes don't specialize and don't use any profiling state. This allows to store them statically and to use them whenever no specialization/profiling is desired. The uncached version of the node is accessible using a static method called getUncached() on the generated node. GenerateUncached is inherited to subclasses if inherit() is set to true (default false).

A node subclass must fullfill the following requirements in order to be uncachable:

• At least one specialization and one execute method must be specified.
• The node has no instance fields.
• All Cached parameters provide valid uncached initializers.
• All guards/cache/limit expressions must not bind the node receiver.

If any of these requirements are violated then an error will be shown. If node uses the NodeChild or NodeField annotations then they will return constant null or the primitive equivalent for the uncached node.

* By default every specialization is included for GenerateUncached, except specializations that require a limit and are replaced, those are excluded by default. By setting Specialization.excludeForUncached() explicitly the default behavior can be overridden, e.g. to include or exclude a specialization for uncached.

Example:

@GenerateUncached
abstract static class UncachableNode extends Node {

    abstract Object execute(Object arg);

    @Specialization(guards = "v == cachedV", limit = "3")
    static Object doCached(int v, @Cached("v") int cachedV) {
        // do cached
    }

    @Specialization(replaces = "doCached")
    static String doGeneric(int v) {
        // do uncached
    }

}

This node produces the following uncached version of the execute method:

@Override
Object execute(Object arg0Value) {
    if (arg0Value instanceof Integer) {
        int arg0Value_ = (int) arg0Value;
        return UncachableNode.doGeneric(arg0Value_);
    }
    throw new UnsupportedSpecializationException(this, new Node[]{null}, arg0Value);
}

Note that the doCached specialization is removed from the uncached version by default. This behavior can be customized by setting Specialization.excludeForUncached().

Since:

19.0

See Also:

• Cached
• Specialization.excludeForUncached()

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element	Description
boolean	inherit	Inherits the semantics of the annotation to subclasses.
boolean	value	If true enables the generation of an uncached version of this specializing node.

Element Details

value

boolean value

If true enables the generation of an uncached version of this specializing node. It is disabled by default.

Since:

19.0

Default:

true

inherit

boolean inherit

Inherits the semantics of the annotation to subclasses.

Since:

19.1.0

Default:

false