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https://issues.apache.org/jira/browse/HIVE-10235?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14495522#comment-14495522
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Chengxiang Li commented on HIVE-10235:
--------------------------------------
Environment:
java version "1.8.0_40"
Java(TM) SE Runtime Environment (build 1.8.0_40-b26)
Java HotSpot(TM) 64-Bit Server VM (build 25.40-b25, mixed mode)
Intel(R) Core(TM) i3-2130 CPU @ 3.40GHz
Linux version 2.6.32-279.el6.x86_64
> Loop optimization for SIMD in ColumnDivideColumn.txt
> ----------------------------------------------------
>
> Key: HIVE-10235
> URL: https://issues.apache.org/jira/browse/HIVE-10235
> Project: Hive
> Issue Type: Sub-task
> Components: Vectorization
> Affects Versions: 1.1.0
> Reporter: Chengxiang Li
> Assignee: Chengxiang Li
> Priority: Minor
> Attachments: HIVE-10235.1.patch
>
>
> Found two loop which could be optimized for packed instruction set during
> execution.
> 1. hasDivBy0 depends on the result of last loop, which prevent the loop be
> executed vectorized.
> {code:java}
> for(int i = 0; i != n; i++) {
> <OperandType2> denom = vector2[i];
> outputVector[i] = vector1[0] <OperatorSymbol> denom;
> hasDivBy0 = hasDivBy0 || (denom == 0);
> }
> {code}
> 2. same as HIVE-10180, vector2\[0\] reference provent JVM optimizing loop
> into packed instruction set.
> {code:java}
> for(int i = 0; i != n; i++) {
> outputVector[i] = vector1[i] <OperatorSymbol> vector2[0];
> }
> {code}
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