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.
static Hop	simplifyConstantConjunction(Hop parent, Hop hi, int pos)

Methods inherited from class java.lang.Object

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

Constructor Details

RewriteAlgebraicSimplificationStatic

public RewriteAlgebraicSimplificationStatic()

Method Details

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

simplifyConstantConjunction

public static Hop simplifyConstantConjunction(Hop parent,
 Hop hi,
 int pos)