at.dms.kjc.backendSupport
Class Channel

java.lang.Object
  at.dms.kjc.backendSupport.Channel

Direct Known Subclasses:

ChannelAsArray, DelegatingChannel, InterSPUChannel, OffChipBuffer, UnbufferredPopChannel, UnbufferredPushChannel

public class Channel
extends Object

A Buffer is an implementation of an Edge in a back end. It refers to nodes in a slice graph like an edge does, but a Buffer also contains code that a back end can emit to pass data between nodes in the slice graph.

Author:

dimock

Field Summary

protected static HashMap<Edge,Channel>	bufferStore the store for all Buffers, indexed by edge.
protected int	extraCount set to 1 for double bufferring or higher if even more extra buffers desired
protected String	ident unique ident for the buffer
protected int	rotationLength the rotation length of this buffer for software pipelining Includes any length from extraLength field.
protected Edge	theEdge Technical note: a Buffer in a backend implements an Edge in a slice graph This data structure uses an Edge to store source, destination, and type information.
protected int	unique_id used to make sure ident is unique

Constructor Summary

protected	Channel(Edge edge) Create a channel given an edge.
protected	Channel(SliceNode src, SliceNode dst) Create a buffer given src and dst SliceNode's

Method Summary

static void	addChannel(Channel c) Add a Channel to our collection of channels.
JMethodDeclaration	assignFromPeekMethod()
String	assignFromPeekMethodName()
JMethodDeclaration	assignFromPopMethod()
String	assignFromPopMethodName()
List<JStatement>	beginInitRead()
List<JStatement>	beginInitWrite()
List<JStatement>	beginSteadyRead()
List<JStatement>	beginSteadyWrite()
List<JStatement>	dataDecls()
List<JStatement>	dataDeclsH()
List<JStatement>	endInitRead()
List<JStatement>	endInitWrite()
List<JStatement>	endSteadyRead()
List<JStatement>	endSteadyWrite()
static Channel	findChannel(Edge edge) Determine whther a channel for an edge exists in out collection of channels.
static Collection<Channel>	getBuffers()
SliceNode	getDest()
int	getExtraCount()
String	getIdent()
SliceNode	getSource()
CType	getType()
JMethodDeclaration	peekMethod()
String	peekMethodName()
JMethodDeclaration	popManyMethod() Pop many items at once ignoring them.
String	popManyMethodName()
JMethodDeclaration	popMethod()
String	popMethodName()
List<JStatement>	postPreworkInitRead()
static void	printBuffers() For debugging.
JMethodDeclaration	pushMethod()
String	pushMethodName()
List<JStatement>	readDecls()
List<JStatement>	readDeclsExtern()
static void	reset() Reset the buffer store and create all number buffer objects.
void	setExtralength(int extracount)
static void	setRotationLengths(BasicSpaceTimeSchedule sched) Set rotation count: number of buffers needed during primePump phase.
List<JStatement>	topOfWorkSteadyRead()
List<JStatement>	topOfWorkSteadyWrite()
List<JStatement>	writeDecls()
List<JStatement>	writeDeclsExtern()

Methods inherited from class java.lang.Object

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

Field Detail

theEdge

protected Edge theEdge

Technical note: a Buffer in a backend implements an Edge in a slice graph This data structure uses an Edge to store source, destination, and type information. XXX fix this? is sharing edges with the sliceGraph can see wanting to optimize buffers to remove useless edges and wanting to change source and dest, presumably without changing slice graph.

ident

protected String ident

unique ident for the buffer

unique_id

protected int unique_id

used to make sure ident is unique

bufferStore

protected static HashMap<Edge,Channel> bufferStore

the store for all Buffers, indexed by edge.

rotationLength

protected int rotationLength

the rotation length of this buffer for software pipelining Includes any length from extraLength field.

extraCount

protected int extraCount

set to 1 for double bufferring or higher if even more extra buffers desired

Constructor Detail

Channel

protected Channel(Edge edge)

Create a channel given an edge. Subclasses should provide factories for their channel types.

Parameters:

edge -

Channel

protected Channel(SliceNode src,
                  SliceNode dst)

Create a buffer given src and dst SliceNode's

Parameters:

src -

dst -

Method Detail

findChannel

public static Channel findChannel(Edge edge)

Determine whther a channel for an edge exists in out collection of channels.

Parameters:

edge - Edge that the channel should implement

Returns:

an existing channel if there is one, else null.

addChannel

public static void addChannel(Channel c)

Add a Channel to our collection of channels.

Parameters:

c - Channel to add to our collection of channels.

reset

public static void reset()

Reset the buffer store and create all number buffer objects. Used if one wants to munge the trace graph.

printBuffers

public static void printBuffers()

For debugging.

getIdent

public String getIdent()

getBuffers

public static Collection<Channel> getBuffers()

Returns:

of the buffers of this stream program

getType

public CType getType()

getExtraCount

public int getExtraCount()

setExtralength

public void setExtralength(int extracount)

getSource

public SliceNode getSource()

getDest

public SliceNode getDest()

setRotationLengths

public static void setRotationLengths(BasicSpaceTimeSchedule sched)

Set rotation count: number of buffers needed during primePump phase. Also adds in extracount to set up double-bufferring if desired.

Parameters:

sched - BasicSpaceTimeSchedule gives primePump multiplicities.

popMethodName

public String popMethodName()

popMethod

public JMethodDeclaration popMethod()

popManyMethodName

public String popManyMethodName()

popManyMethod

public JMethodDeclaration popManyMethod()

Pop many items at once ignoring them. Default method generated here to call popMethod() repeatedly.

assignFromPopMethodName

public String assignFromPopMethodName()

assignFromPopMethod

public JMethodDeclaration assignFromPopMethod()

peekMethodName

public String peekMethodName()

peekMethod

public JMethodDeclaration peekMethod()

assignFromPeekMethodName

public String assignFromPeekMethodName()

assignFromPeekMethod

public JMethodDeclaration assignFromPeekMethod()

pushMethodName

public String pushMethodName()

pushMethod

public JMethodDeclaration pushMethod()

beginInitRead

public List<JStatement> beginInitRead()

postPreworkInitRead

public List<JStatement> postPreworkInitRead()

endInitRead

public List<JStatement> endInitRead()

beginInitWrite

public List<JStatement> beginInitWrite()

endInitWrite

public List<JStatement> endInitWrite()

beginSteadyRead

public List<JStatement> beginSteadyRead()

endSteadyRead

public List<JStatement> endSteadyRead()

beginSteadyWrite

public List<JStatement> beginSteadyWrite()

endSteadyWrite

public List<JStatement> endSteadyWrite()

topOfWorkSteadyRead

public List<JStatement> topOfWorkSteadyRead()

topOfWorkSteadyWrite

public List<JStatement> topOfWorkSteadyWrite()

dataDeclsH

public List<JStatement> dataDeclsH()

dataDecls

public List<JStatement> dataDecls()

readDeclsExtern

public List<JStatement> readDeclsExtern()

readDecls

public List<JStatement> readDecls()

writeDeclsExtern

public List<JStatement> writeDeclsExtern()

writeDecls

public List<JStatement> writeDecls()