Package org.apache.sysds.hops.rewrite
Class RewriteRemoveReadAfterWrite
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- org.apache.sysds.hops.rewrite.HopRewriteRule
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- org.apache.sysds.hops.rewrite.RewriteRemoveReadAfterWrite
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public class RewriteRemoveReadAfterWrite extends HopRewriteRule
Rule: RemoveReadAfterWrite. If there is a persistent read with the same filename as a persistent write, and read has a higher line number than the write, we remove the read and consume the write input directly. This is important for two reasons (1) correctness and (2) performance. Without this rewrite, we could not guarantee the order of read-after-write because there is not data dependency
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Constructor Summary
Constructors Constructor Description RewriteRemoveReadAfterWrite()
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description HoprewriteHopDAG(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.
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Method Detail
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rewriteHopDAGs
public ArrayList<Hop> rewriteHopDAGs(ArrayList<Hop> roots, ProgramRewriteStatus state)
Description copied from class:HopRewriteRuleHandle a generic (last-level) hop DAG with multiple roots.- Specified by:
rewriteHopDAGsin classHopRewriteRule- Parameters:
roots- high-level operator rootsstate- program rewrite status- Returns:
- list of high-level operators
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rewriteHopDAG
public Hop rewriteHopDAG(Hop root, ProgramRewriteStatus state)
Description copied from class:HopRewriteRuleHandle a predicate hop DAG with exactly one root.- Specified by:
rewriteHopDAGin classHopRewriteRule- Parameters:
root- high-level operator rootstate- program rewrite status- Returns:
- high-level operator
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