org.jikesrvm.compilers.opt.ssa

Class LiveRangeSplitting.LiveRangeSplittingPhase

java.lang.Object

org.jikesrvm.compilers.opt.driver.CompilerPhase

org.jikesrvm.compilers.opt.ssa.LiveRangeSplitting.LiveRangeSplittingPhase

Enclosing class:

LiveRangeSplitting

private static class LiveRangeSplitting.LiveRangeSplittingPhase
extends CompilerPhase

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	LiveRangeSplitting.LiveRangeSplittingPhase.BasicBlockPair A utility class to represent an edge in the CFG.

Field Summary

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

container

Constructor Summary

Constructors

Modifier	Constructor and Description
private	LiveRangeSplittingPhase()

Method Summary

Modifier and Type	Method and Description
private static void	addEntriesForInfrequentBlocks(IR ir, LiveAnalysis live, HashMap<LiveRangeSplitting.LiveRangeSplittingPhase.BasicBlockPair,HashSet<Register>> result) Split live ranges on entry and exit to infrequent regions.
private static HashSet<Register>	findOrCreateSplitSet(HashMap<LiveRangeSplitting.LiveRangeSplittingPhase.BasicBlockPair,HashSet<Register>> map, BasicBlock b1, BasicBlock b2) Given a mapping from BasicBlockPair -> HashSet, find or create the hash set corresponding to a given basic block pair
private static HashMap<LiveRangeSplitting.LiveRangeSplittingPhase.BasicBlockPair,HashSet<Register>>	findSplitPoints(IR ir, LiveAnalysis live, LSTGraph lst) Find the points the IR where live ranges should be split.
String	getName()
CompilerPhase	newExecution(IR ir) Return this instance of this phase.
void	perform(IR ir) This is the method that actually does the work of the phase.
boolean	shouldPerform(OptOptions options) This method determines if the phase should be run, based on the Options object it is passed.
private static void	transform(IR ir, HashMap<LiveRangeSplitting.LiveRangeSplittingPhase.BasicBlockPair,HashSet<Register>> xform) Perform the transformation

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

LiveRangeSplittingPhase

private LiveRangeSplittingPhase()

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.

perform

public final void perform(IR ir)

Description copied from class: CompilerPhase

This is the method that actually does the work of the phase.

Specified by:

perform in class CompilerPhase

Parameters:

ir - the IR on which to apply the phase

findSplitPoints

private static HashMap<LiveRangeSplitting.LiveRangeSplittingPhase.BasicBlockPair,HashSet<Register>> findSplitPoints(IR ir,
                                                                                                                    LiveAnalysis live,
                                                                                                                    LSTGraph lst)

Find the points the IR where live ranges should be split.

Parameters:

ir - the governing IR

live - valid liveness information

lst - a valid loop structure tree

Returns:

the result as a mapping from BasicBlockPair to a set of registers

addEntriesForInfrequentBlocks

private static void addEntriesForInfrequentBlocks(IR ir,
                                                  LiveAnalysis live,
                                                  HashMap<LiveRangeSplitting.LiveRangeSplittingPhase.BasicBlockPair,HashSet<Register>> result)

Split live ranges on entry and exit to infrequent regions. Add this information to 'result', a mapping from BasicBlockPair to a set of registers to split.

Parameters:

ir - the governing IR

live - valid liveness information

result - mapping from BasicBlockPair to a set of registers

findOrCreateSplitSet

private static HashSet<Register> findOrCreateSplitSet(HashMap<LiveRangeSplitting.LiveRangeSplittingPhase.BasicBlockPair,HashSet<Register>> map,
                                                      BasicBlock b1,
                                                      BasicBlock b2)

Given a mapping from BasicBlockPair -> HashSet, find or create the hash set corresponding to a given basic block pair

Parameters:

map - the mapping to search

b1 - the first basic block in the pair

b2 - the second basic block in the pair

Returns:

the set corresponding to the basic block pair

transform

private static void transform(IR ir,
                              HashMap<LiveRangeSplitting.LiveRangeSplittingPhase.BasicBlockPair,HashSet<Register>> xform)

Perform the transformation

Parameters:

ir - the governing IR

xform - a mapping from BasicBlockPair to the set of registers to split