com.oracle.svm.core.graal.phases

Class RemoveUnwindPhase

java.lang.Object

org.graalvm.compiler.phases.BasePhase<Object>

org.graalvm.compiler.phases.Phase

com.oracle.svm.core.graal.phases.RemoveUnwindPhase

All Implemented Interfaces:

org.graalvm.compiler.phases.contract.PhaseSizeContract

public class RemoveUnwindPhase
extends org.graalvm.compiler.phases.Phase

The exception handling mechanism of Substrate VM is capable of jumping over methods that have no exception handler registered. That saves us from emitting boilerplate code in every call site in every method that just forwards the exception object from the InvokeWithExceptionNode to the UnwindNode.

Nested Class Summary

Nested classes/interfaces inherited from class org.graalvm.compiler.phases.BasePhase

org.graalvm.compiler.phases.BasePhase.BasePhaseStatistics, org.graalvm.compiler.phases.BasePhase.PhaseOptions

Constructor Summary

Constructors

Constructor and Description
RemoveUnwindPhase()

Method Summary

Modifier and Type	Method and Description
protected void	run(org.graalvm.compiler.nodes.StructuredGraph graph)
protected void	walkBack(org.graalvm.compiler.graph.Node n, org.graalvm.compiler.graph.Node successor, List<org.graalvm.compiler.nodes.InvokeWithExceptionNode> invocations) We walk back from the UnwindNode to an InvokeWithExceptionNode.

Methods inherited from class org.graalvm.compiler.phases.Phase

apply, apply, run

Methods inherited from class org.graalvm.compiler.phases.BasePhase

apply, apply, codeSizeIncrease, contractorName, getName, shouldDumpAfterAtBasicLevel, shouldDumpBeforeAtBasicLevel

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.graalvm.compiler.phases.contract.PhaseSizeContract

checkContract

Constructor Detail

RemoveUnwindPhase

public RemoveUnwindPhase()

Method Detail

run

protected void run(org.graalvm.compiler.nodes.StructuredGraph graph)

Specified by:

run in class org.graalvm.compiler.phases.Phase

walkBack

protected void walkBack(org.graalvm.compiler.graph.Node n,
                        org.graalvm.compiler.graph.Node successor,
                        List<org.graalvm.compiler.nodes.InvokeWithExceptionNode> invocations)

We walk back from the UnwindNode to an InvokeWithExceptionNode. If the control flow path only contains nodes white-listed in this method, then we know that we have an invoke that just forwards the exception to the UnwindNode. Such invokes are rewritten to a plain InvokeNode, i.e., no exception handler entry is created for such invokes.