org.jikesrvm.compilers.opt.escape

Class EscapeTransformations

java.lang.Object

org.jikesrvm.compilers.opt.driver.CompilerPhase

org.jikesrvm.compilers.opt.escape.EscapeTransformations

public class EscapeTransformations
extends CompilerPhase

Transformations that use escape analysis.

• 1. synchronization removal
• 2. scalar replacement of aggregates and short arrays

Field Summary

Fields

Modifier and Type	Field and Description
private static OptimizationPlanElement	escapeCleanUp Transforms to clean the IR prior to another round of escape transformations

Fields inherited from class org.jikesrvm.compilers.opt.driver.CompilerPhase

container

Constructor Summary

Constructors

Constructor and Description
EscapeTransformations()

Method Summary

Modifier and Type	Method and Description
private AggregateReplacer	getAggregateReplacer(Instruction inst, IR ir) Generate an object which will perform scalar replacement of an aggregate allocated by a given instruction PRECONDITION: objects returned by this allocation site do NOT escape the current method
String	getName()
private UnsyncReplacer	getUnsyncReplacer(Register reg, Instruction inst, IR ir) Generate an object which transforms defs & uses of "synchronized" objects to defs & uses of "unsynchronized" objects PRECONDITION: objects pointed to by reg do NOT escape
CompilerPhase	newExecution(IR ir) Return this instance of this phase.
void	perform(IR ir) Perform the transformations
boolean	printingEnabled(OptOptions options, boolean before) Returns true if the phase wants the IR dumped before and/or after it runs.
boolean	shouldPerform(OptOptions options) This method determines if the phase should be run, based on the Options object it is passed.
private static boolean	synchronizesOn(Register r) Is there an instruction in this IR which causes synchronization on an object pointed to by a particular register?

Methods inherited from class org.jikesrvm.compilers.opt.driver.CompilerPhase

dumpIR, dumpIR, getClassConstructor, getCompilerPhaseConstructor, getCompilerPhaseConstructor, performPhase, reportAdditionalStats, setContainer, verify

Methods inherited from class java.lang.Object

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

Field Detail

escapeCleanUp

private static final OptimizationPlanElement escapeCleanUp

Transforms to clean the IR prior to another round of escape transformations

Constructor Detail

EscapeTransformations

public EscapeTransformations()

Method Detail

newExecution

public CompilerPhase newExecution(IR ir)

Return this instance of this phase. This phase contains no per-compilation instance fields.

Overrides:

newExecution in class CompilerPhase

Parameters:

ir - not used

Returns:

this

shouldPerform

public final boolean shouldPerform(OptOptions options)

Description copied from class: CompilerPhase

This method determines if the phase should be run, based on the Options object it is passed. By default, phases are always performed. Subclasses should override this method if they only want to be performed conditionally.

Overrides:

shouldPerform in class CompilerPhase

Parameters:

options - the compiler options for the compilation

Returns:

true if the phase should be performed

getName

public final String getName()

Specified by:

getName in class CompilerPhase

Returns:

a String which is the name of the phase.

printingEnabled

public final boolean printingEnabled(OptOptions options,
                                     boolean before)

Description copied from class: CompilerPhase

Returns true if the phase wants the IR dumped before and/or after it runs. By default, printing is not enabled. Subclasses should override this method if they want to provide IR dumping.

Overrides:

printingEnabled in class CompilerPhase

Parameters:

options - the compiler options for the compilation

before - true when invoked before perform, false otherwise.

Returns:

true if the IR should be printed, false otherwise.

perform

public void perform(IR ir)

Perform the transformations

Specified by:

perform in class CompilerPhase

Parameters:

ir - IR for the target method

getUnsyncReplacer

private UnsyncReplacer getUnsyncReplacer(Register reg,
                                         Instruction inst,
                                         IR ir)

Generate an object which transforms defs & uses of "synchronized" objects to defs & uses of "unsynchronized" objects

PRECONDITION: objects pointed to by reg do NOT escape

Parameters:

reg - the pointer whose defs and uses should be transformed

inst - the allocation site

ir - controlling ir

Returns:

an UnsyncReplacer specialized to the allocation site, null if no legal transformation found

synchronizesOn

private static boolean synchronizesOn(Register r)

Is there an instruction in this IR which causes synchronization on an object pointed to by a particular register? PRECONDITION: register lists computed and valid

Parameters:

r - the object's register

Returns:

whether synchronization occurs on the given object

getAggregateReplacer

private AggregateReplacer getAggregateReplacer(Instruction inst,
                                               IR ir)

Generate an object which will perform scalar replacement of an aggregate allocated by a given instruction

PRECONDITION: objects returned by this allocation site do NOT escape the current method

Parameters:

inst - the allocation site

ir - controlling ir

Returns:

an AggregateReplacer specialized to the allocation site, null if no legal transformation found