Package org.apache.sysds.hops.rewrite

Class RewriteIndexingVectorization

java.lang.Object

org.apache.sysds.hops.rewrite.HopRewriteRule

org.apache.sysds.hops.rewrite.RewriteIndexingVectorization

public class RewriteIndexingVectorization
extends HopRewriteRule

Rule: Indexing vectorization. This rewrite rule set simplifies multiple right / left indexing accesses within a DAG into row/column index accesses, which is beneficial for two reasons: (1) it is an enabler for later row/column partitioning, and (2) it reduces the number of operations over potentially large data (i.e., prevents unnecessary MR operations and reduces pressure on the buffer pool due to copy on write on left indexing).

Constructor Summary

Constructors

Constructor	Description
RewriteIndexingVectorization()

Method Summary

Modifier and Type	Method	Description
Hop	rewriteHopDAG(Hop root, ProgramRewriteStatus state)	Handle a predicate hop DAG with exactly one root.
ArrayList<Hop>	rewriteHopDAGs(ArrayList<Hop> roots, ProgramRewriteStatus state)	Handle a generic (last-level) hop DAG with multiple roots.

Methods inherited from class java.lang.Object

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

Constructor Detail

RewriteIndexingVectorization

public RewriteIndexingVectorization()

Method Detail

rewriteHopDAGs

public ArrayList<Hop> rewriteHopDAGs(ArrayList<Hop> roots,
                                     ProgramRewriteStatus state)

Description copied from class: HopRewriteRule

Handle a generic (last-level) hop DAG with multiple roots.

Specified by:

rewriteHopDAGs in class HopRewriteRule

Parameters:

roots - high-level operator roots

state - program rewrite status

Returns:

list of high-level operators

rewriteHopDAG

public Hop rewriteHopDAG(Hop root,
                         ProgramRewriteStatus state)

Description copied from class: HopRewriteRule

Handle a predicate hop DAG with exactly one root.

Specified by:

rewriteHopDAG in class HopRewriteRule

Parameters:

root - high-level operator root

state - program rewrite status

Returns:

high-level operator