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From "Gopal V" <go...@hortonworks.com>
Subject Re: Review Request 32918: HIVE-10180 Loop optimization for SIMD in ColumnArithmeticColumn.txt
Date Tue, 07 Apr 2015 05:49:31 GMT

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This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/32918/#review79126
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Ship it!


Minor comments about final vars, to make it clearer to read.


trunk/ql/src/gen/vectorization/ExpressionTemplates/ColumnArithmeticColumn.txt
<https://reviews.apache.org/r/32918/#comment128251>

    For the sake clarity, can you mark these as final variables?



trunk/ql/src/gen/vectorization/ExpressionTemplates/ColumnArithmeticColumn.txt
<https://reviews.apache.org/r/32918/#comment128252>

    Final vars for the other case


- Gopal V


On April 7, 2015, 5:46 a.m., chengxiang li wrote:
> 
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> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/32918/
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> 
> (Updated April 7, 2015, 5:46 a.m.)
> 
> 
> Review request for hive.
> 
> 
> Bugs: Hive-10180
>     https://issues.apache.org/jira/browse/Hive-10180
> 
> 
> Repository: hive
> 
> 
> Description
> -------
> 
> JVM is quite strict on the code schema which may executed with SIMD instructions, take
a loop in DoubleColAddDoubleColumn.java for example,
> for (int i = 0; i != n; i++) {
>   outputVector[i] = vector1[0] + vector2[i];
> }
> The "vector1[0]" reference would prevent JVM to execute this part of code with vectorized
instructions, we need to assign the "vector1[0]" to a variable outside of loop, and use that
variable in loop.
> 
> 
> Diffs
> -----
> 
>   trunk/ql/src/gen/vectorization/ExpressionTemplates/ColumnArithmeticColumn.txt 1671736

> 
> Diff: https://reviews.apache.org/r/32918/diff/
> 
> 
> Testing
> -------
> 
> 
> Thanks,
> 
> chengxiang li
> 
>


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