org.jikesrvm.compilers.opt.ir

Class ExceptionHandlerBasicBlock

java.lang.Object

org.jikesrvm.compilers.opt.util.SpaceEffGraphNode

org.jikesrvm.compilers.opt.util.SortedGraphNode

org.jikesrvm.compilers.opt.ir.BasicBlock

org.jikesrvm.compilers.opt.ir.ExceptionHandlerBasicBlock

All Implemented Interfaces:

GraphNode

public final class ExceptionHandlerBasicBlock
extends BasicBlock

A basic block that marks the start of an exception handler. Exception Handler Basic Block; acronym EHBB.

Nested Class Summary

Nested classes/interfaces inherited from class org.jikesrvm.compilers.opt.ir.BasicBlock

BasicBlock.BBEnum, BasicBlock.ComputedBBEnum, BasicBlock.ExceptionOutEdgeEnum, BasicBlock.InEdgeEnum, BasicBlock.NormalOutEdgeEnum, BasicBlock.OutEdgeEnum

Nested classes/interfaces inherited from class org.jikesrvm.compilers.opt.util.SpaceEffGraphNode

SpaceEffGraphNode.GraphEdgeEnumeration<T extends GraphEdge>, SpaceEffGraphNode.OutEdgeEnumeration

Field Summary

Fields

Modifier and Type	Field and Description
private TypeOperand[]	exceptionTypes The RVMType(s) of the exception(s) caught by this block.
private LiveSet	liveSet The liveness information at the beginning of this block.

Fields inherited from class org.jikesrvm.compilers.opt.ir.BasicBlock

CAN_THROW_EXCEPTIONS, end, EXCEPTION_HANDLER, EXCEPTION_HANDLER_WITH_NORMAL_IN, exceptionHandlers, flags, freq, IMPLICIT_EXIT_EDGE, INFREQUENT, LANDING_PAD, REACHABLE_FROM_EXCEPTION_HANDLER, SCRATCH, start

Fields inherited from class org.jikesrvm.compilers.opt.util.SortedGraphNode

backwardSortNumber, forwardSortNumber, sortedNext, sortedPrev

Fields inherited from class org.jikesrvm.compilers.opt.util.SpaceEffGraphNode

_inEdgeEnd, _inEdgeStart, _outEdgeEnd, _outEdgeStart, info, next, nextSorted, prev

Constructor Summary

Constructors

Constructor and Description
ExceptionHandlerBasicBlock(int loc, InlineSequence position, TypeOperand type, ControlFlowGraph cfg) Creates a new exception handler basic block at the specified location, which catches the specified type of exception.

Method Summary

Modifier and Type	Method and Description
void	addCaughtException(TypeOperand et) Add a new exception type to an extant exception handler block.
Enumeration<TypeOperand>	getExceptionTypes() This method is mainly intended for creation of exception tables during final assembly.
LiveSet	getLiveSet() Returns the set of registers live before the first instruction of this basic block
int	getNumberOfExceptionTableEntries() Gets the number of table entries required for this EHBB.
byte	mayCatchException(TypeReference cand) Return YES/NO/MAYBE values that answer the question is it possible for this handler block to catch an exception of the type et.
byte	mustCatchException(TypeReference cand) Return YES/NO/MAYBE values that answer the question is it guarenteed that this handler block will catch an exception of type cand
void	setLiveSet(LiveSet liveSet) Set the set of registers live before the first instruction of this basic block
String	toString() Return a string representation of the basic block (augment BasicBlock.toString() with the exceptions caught by this handler block).

Methods inherited from class org.jikesrvm.compilers.opt.ir.BasicBlock

appendInstruction, appendInstructionRespectingTerminalBranch, appendInstructionRespectingTerminalBranchOrPEI, augmentExecutionFrequency, canThrowExceptions, clearCanThrowExceptions, clearExceptionHandlerBasicBlock, clearInfrequent, clearLandingPad, clearMayThrowUncaughtException, clearReachableFromExceptionHandler, clearScratchFlag, copyWithoutLinks, createSubBlock, createSubBlock, deleteNormalOut, discardInstructions, enumerateBranchInstructions, firstBranchInstruction, firstInstruction, firstRealInstruction, forwardInstrEnumerator, forwardRealInstrEnumerator, getApplicableExceptionalOut, getExceptionalOut, getExceptionHandlers, getExecutionFrequency, getFallThroughBlock, getIn, getInfrequent, getInNodes, getLandingPad, getNormalOut, getNotTakenNextBlock, getNumberOfExceptionalOut, getNumberOfNormalOut, getNumberOfRealInstructions, getOut, getOutNodes, getReachableExceptionHandlers, getScratchFlag, hasApplicableExceptionalOut, hasAthrowInst, hasExceptionHandlers, hasGoto, hasNonReturningCall, hasNonReturningOsr, hasReachableExceptionHandlers, hasReturn, hasSwitch, hasTrap, initInOutSets, isEmpty, isExceptionalOut, isExceptionHandlerBasicBlock, isExceptionHandlerEquivalent, isExceptionHandlerWithNormalIn, isExit, isIn, isNormalOut, isOut, isReachableFromExceptionHandler, killFallThrough, lastInstruction, lastRealInstruction, makeExit, makeGOTO, makeJumpTarget, mayThrowUncaughtException, mergeFallThrough, moveBehind, nextBasicBlockInCodeOrder, prependInstruction, prependInstructionRespectingPrologue, prevBasicBlockInCodeOrder, printExtended, pruneExceptionalOut, recomputeNormalOut, redirectOuts, replicateNormalOut, replicateThisOut, replicateThisOut, reverseInstrEnumerator, reverseRealInstrEnumerator, scaleExecutionFrequency, segregateInstruction, setCanThrowExceptions, setExceptionHandlerBasicBlock, setExceptionHandlerWithNormalIn, setExecutionFrequency, setInfrequent, setInfrequent, setLandingPad, setMayThrowUncaughtException, setReachableFromExceptionHandler, setScratchFlag, splitNodeAt, splitNodeWithLinksAt, unfactor

Methods inherited from class org.jikesrvm.compilers.opt.util.SortedGraphNode

getBackwardSortedNext, getBackwardSortNumber, getForwardSortedNext, getForwardSortNumber, getNewSortMarker, getSortedNext, getSortMarker, getSortNumber, isSortMarkedWith, setBackwardSortNumber, setForwardSortNumber, setSortedNext, setSortMarker, setSortNumber, setSortNumber

Methods inherited from class org.jikesrvm.compilers.opt.util.SpaceEffGraphNode

_sortDFS, _sortRevTop, _sortTop, append, appendInEdge, appendOutEdge, clearDfsVisited, clearFlags, clearInFlags, clearLoopHeader, clearOnStack, clearOutFlags, clearTopVisited, deleteIn, deleteOut, deleteOut, deleteOut, dfsVisited, findOutEdgeTo, firstInEdge, firstInNode, firstOutEdge, firstOutNode, flagsOn, getIndex, getNext, getNumber, getNumberOfIn, getNumberOfOut, getPrev, hasIn, hasOneIn, hasOneIn, hasOneOut, hasOneOut, hasOut, hasZeroIn, hasZeroOut, inEdges, inNodes, insertOut, insertOut, isLoopHeader, onStack, outEdges, outNodes, pointsIn, pointsOut, printInEdges, printInNodes, printOutEdges, printOutNodes, remove, removeIn, removeIn, removeOut, removeOut, replaceInEdge, replaceOut, setDfsVisited, setDfsVisitedOnStack, setIndex, setLoopHeader, setNumber, setOnStack, setTopVisited, sortDFS, sortRevTop, sortTop, topVisited

Methods inherited from class java.lang.Object

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

Field Detail

exceptionTypes

private TypeOperand[] exceptionTypes

The RVMType(s) of the exception(s) caught by this block.

liveSet

private LiveSet liveSet

The liveness information at the beginning of this block.

NOTE: If we decide to store this for all blocks, we should move this field to BasicBlock (the parent class)

Constructor Detail

ExceptionHandlerBasicBlock

public ExceptionHandlerBasicBlock(int loc,
                                  InlineSequence position,
                                  TypeOperand type,
                                  ControlFlowGraph cfg)

Creates a new exception handler basic block at the specified location, which catches the specified type of exception.

Parameters:

loc - Bytecode index to create basic block at

position - The inline context for this basic block

type - The exception type

cfg - The ControlFlowGraph that will contain the basic block

Method Detail

addCaughtException

public void addCaughtException(TypeOperand et)

Add a new exception type to an extant exception handler block. Do filtering of duplicates internally for efficiency. NOTE: this routine is only intended to be called by BC2IR.

Parameters:

et - the exception type to be added

mayCatchException

public byte mayCatchException(TypeReference cand)

Return YES/NO/MAYBE values that answer the question is it possible for this handler block to catch an exception of the type et.

Parameters:

cand - the TypeReference of the exception in question.

Returns:

YES, NO, MAYBE

mustCatchException

public byte mustCatchException(TypeReference cand)

Return YES/NO/MAYBE values that answer the question is it guarenteed that this handler block will catch an exception of type cand

Parameters:

cand - the TypeReference of the exception in question.

Returns:

YES, NO, MAYBE

getExceptionTypes

public Enumeration<TypeOperand> getExceptionTypes()

This method is mainly intended for creation of exception tables during final assembly. Most other clients shouldn't care about this level of detail.

Returns:

an Enumeration of the caught exception types

getNumberOfExceptionTableEntries

public int getNumberOfExceptionTableEntries()

Gets the number of table entries required for this EHBB.

Really only of interest during final assembly.

Returns:

the number of table entries for this basic block

See Also:

exception table and its opt-compiler specific subclasses

getLiveSet

public LiveSet getLiveSet()

Returns the set of registers live before the first instruction of this basic block

Returns:

the set of registers live before the first instruction of this basic block

setLiveSet

public void setLiveSet(LiveSet liveSet)

Set the set of registers live before the first instruction of this basic block

Parameters:

liveSet - The set of registers live before the first instruction of this basic block

toString

public String toString()

Return a string representation of the basic block (augment BasicBlock.toString() with the exceptions caught by this handler block).

Overrides:

toString in class BasicBlock

Returns:

a string representation of the block