Package org.apache.sysds.hops.rewrite

Class RewriteInjectOOCTee

java.lang.Object

org.apache.sysds.hops.rewrite.StatementBlockRewriteRule

org.apache.sysds.hops.rewrite.RewriteInjectOOCTee

public class RewriteInjectOOCTee
extends StatementBlockRewriteRule

This Rewrite rule injects a Tee Operator for specific Out-Of-Core (OOC) patterns where a value or an intermediate result is shared twice. Since for OOC we data streams can only be consumed once.

Pattern identified t(X) %*% X, where the data X will be shared by t(X) and %*% multiplication.

The rewrite uses a stable two-pass approach: 1. Find candidates (Read-Only): Traverse the entire HOP DAG to identify candidates the fit the target pattern. 2. Apply Rewrites (Modification): Iterate over the collected candidate and put TeeOp, and safely rewire the graph.

Field Summary

Fields

Modifier and Type	Field	Description
static boolean	APPLY_ONLY_XtX_PATTERN

Constructor Summary

Constructors

Constructor	Description
RewriteInjectOOCTee()

Method Summary

Modifier and Type	Method	Description
boolean	createsSplitDag()	Indicates if the rewrite potentially splits dags, which is used for phase ordering of rewrites.
List<StatementBlock>	rewriteStatementBlock(StatementBlock sb, ProgramRewriteStatus state)	Handle an arbitrary statement block.
List<StatementBlock>	rewriteStatementBlocks(List<StatementBlock> sbs, ProgramRewriteStatus state)	Handle a list of statement blocks.

Methods inherited from class org.apache.sysds.hops.rewrite.StatementBlockRewriteRule

createCutVarName

Methods inherited from class java.lang.Object

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

Field Details

APPLY_ONLY_XtX_PATTERN

public static boolean APPLY_ONLY_XtX_PATTERN

Constructor Details

RewriteInjectOOCTee

public RewriteInjectOOCTee()

Method Details

createsSplitDag

public boolean createsSplitDag()

Description copied from class: StatementBlockRewriteRule

Indicates if the rewrite potentially splits dags, which is used for phase ordering of rewrites.

Specified by:

createsSplitDag in class StatementBlockRewriteRule

Returns:

true if dag splits are possible.

rewriteStatementBlock

public List<StatementBlock> rewriteStatementBlock(StatementBlock sb,
 ProgramRewriteStatus state)

Description copied from class: StatementBlockRewriteRule

Handle an arbitrary statement block. Specific type constraints have to be ensured within the individual rewrites. If a rewrite does not apply to individual blocks, it should simply return the input block.

Specified by:

rewriteStatementBlock in class StatementBlockRewriteRule

Parameters:

sb - statement block

state - program rewrite status

Returns:

list of statement blocks

rewriteStatementBlocks

public List<StatementBlock> rewriteStatementBlocks(List<StatementBlock> sbs,
 ProgramRewriteStatus state)

Description copied from class: StatementBlockRewriteRule

Handle a list of statement blocks. Specific type constraints have to be ensured within the individual rewrites. If a rewrite does not require sequence access, it should simply return the input list of statement blocks.

Specified by:

rewriteStatementBlocks in class StatementBlockRewriteRule

Parameters:

sbs - list of statement blocks

state - program rewrite status

Returns:

list of statement blocks