Package com.oracle.truffle.api

Class HostCompilerDirectives

java.lang.Object

com.oracle.truffle.api.HostCompilerDirectives

public final class HostCompilerDirectives
extends Object

Directives that influence the optimizations of the host compiler. These operations affect how the Truffle interpreter is itself compiled.

Since:

21.0

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static @interface	HostCompilerDirectives.BytecodeInterpreterSwitch	Marks a method that is an implementation of a Truffle interpreter, and which should receive additional optimization budget.
static @interface	HostCompilerDirectives.BytecodeInterpreterSwitchBoundary	Deprecated. use is no longer needed.
static @interface	HostCompilerDirectives.InliningCutoff	Hints to Truffle host inlining that a particular method is partial evaluatable, but it would be a good place for a cutoff when performing host inlining.

Method Summary

Modifier and Type	Method	Description
static boolean	inInterpreterFastPath()	Indicates whether a branch is executed only in the interpreter.

Methods inherited from class java.lang.Object

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

Method Details

inInterpreterFastPath

public static boolean inInterpreterFastPath()

Indicates whether a branch is executed only in the interpreter. In addition to CompilerDirectives.inInterpreter(), this method instructs the host compiler to treat the positive branch as frequently executed code of high importance. Branches protected by this method should be treated as if they were runtime compiled code paths, even if they may never actually be compiled. This means that slow-paths must be protected using either CompilerDirectives.transferToInterpreterAndInvalidate() or CompilerDirectives.TruffleBoundary.

A common use case for this directive is in counting condition profiles, where counters must be protected by CompilerDirectives.inInterpreter() but also need to be optimized as fast-path by the host compiler. Without this directive, the host compiler may treat the branch as a slow-path branch.

Returns:

true if executed in the interpreter, false in compiled code.

Since:

23.0