Package org.apache.sysds.hops.rewrite

Class RewriteAlgebraicSimplificationStatic

java.lang.Object

org.apache.sysds.hops.rewrite.HopRewriteRule

org.apache.sysds.hops.rewrite.RewriteAlgebraicSimplificationStatic

public class RewriteAlgebraicSimplificationStatic
extends HopRewriteRule

Rule: Algebraic Simplifications. Simplifies binary expressions in terms of two major purposes: (1) rewrite binary operations to unary operations when possible (in CP this reduces the memory estimate, in MR this allows map-only operations and hence prevents unnecessary shuffle and sort) and (2) remove binary operations that are in itself are unnecessary (e.g., *1 and /1).

Constructor Summary

Constructors

Constructor	Description
RewriteAlgebraicSimplificationStatic()

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

RewriteAlgebraicSimplificationStatic

public RewriteAlgebraicSimplificationStatic()

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