RFR: 8322768: Optimize non-subword vector compress and expand APIs for AVX2 target. [v9]

[Emanuel Peter]

On Tue, 23 Jan 2024 11:56:58 GMT, Jatin Bhateja <jbhateja at openjdk.org> wrote:

>> Hi,
>> 
>> Patch optimizes non-subword vector compress and expand APIs for x86 AVX2 only targets.
>> Upcoming E-core Xeons (Sierra Forest) and Hybrid CPUs only support AVX2 instruction set.
>> These are very frequently used APIs in columnar database filter operation.
>> 
>> Implementation uses a lookup table to record permute indices. Table index is computed using
>> mask argument of compress/expand operation.
>> 
>> Following are the performance number of JMH micro included with the patch.
>> 
>> 
>> System : Intel(R) Xeon(R) Platinum 8480+ (Sapphire Rapids)
>> 
>> Baseline:
>> Benchmark                                 (size)   Mode  Cnt    Score   Error   Units
>> ColumnFilterBenchmark.filterDoubleColumn    1024  thrpt    2  142.767          ops/ms
>> ColumnFilterBenchmark.filterDoubleColumn    2047  thrpt    2   71.436          ops/ms
>> ColumnFilterBenchmark.filterDoubleColumn    4096  thrpt    2   35.992          ops/ms
>> ColumnFilterBenchmark.filterFloatColumn     1024  thrpt    2  182.151          ops/ms
>> ColumnFilterBenchmark.filterFloatColumn     2047  thrpt    2   91.096          ops/ms
>> ColumnFilterBenchmark.filterFloatColumn     4096  thrpt    2   44.757          ops/ms
>> ColumnFilterBenchmark.filterIntColumn       1024  thrpt    2  184.099          ops/ms
>> ColumnFilterBenchmark.filterIntColumn       2047  thrpt    2   91.981          ops/ms
>> ColumnFilterBenchmark.filterIntColumn       4096  thrpt    2   45.170          ops/ms
>> ColumnFilterBenchmark.filterLongColumn      1024  thrpt    2  148.017          ops/ms
>> ColumnFilterBenchmark.filterLongColumn      2047  thrpt    2   73.516          ops/ms
>> ColumnFilterBenchmark.filterLongColumn      4096  thrpt    2   36.844          ops/ms
>> 
>> Withopt:
>> Benchmark                                 (size)   Mode  Cnt     Score   Error   Units
>> ColumnFilterBenchmark.filterDoubleColumn    1024  thrpt    2  2051.707          ops/ms
>> ColumnFilterBenchmark.filterDoubleColumn    2047  thrpt    2   914.072          ops/ms
>> ColumnFilterBenchmark.filterDoubleColumn    4096  thrpt    2   489.898          ops/ms
>> ColumnFilterBenchmark.filterFloatColumn     1024  thrpt    2  5324.195          ops/ms
>> ColumnFilterBenchmark.filterFloatColumn     2047  thrpt    2  2587.229          ops/ms
>> ColumnFilterBenchmark.filterFloatColumn     4096  thrpt    2  1278.665          ops/ms
>> ColumnFilterBenchmark.filterIntColumn       1024  thrpt    2  4149.384          ops/ms
>> ColumnFilterBenchmark.filterIntColumn       2047  thrpt  ...
>
> Jatin Bhateja has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 10 additional commits since the last revision:
> 
>  - Merge branch 'master' of http://github.com/openjdk/jdk into JDK-8322768
>  - Modifying comments.
>  - Review comments resolution
>  - Modified code comment for clarity.
>  - Space fixup
>  - Using emulated variable blend E-Core optimized instruction.
>  - Review suggestions incorporated.
>  - Review comments resolutions.
>  - Updating copyright year of modified files.
>  - 8322768: Optimize non-subword vector compress and expand APIs for AVX2 target.

Testing passed, looks good now :)
Nice progress, the code now is simpler and much more understandable!

-------------

Marked as reviewed by epeter (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/17261#pullrequestreview-1843198049