RFR: 8259278: Optimize Vector API slice and unslice operations [v2]

[Vladimir Ivanov]

On Thu, 7 Jan 2021 00:33:13 GMT, Sandhya Viswanathan <sviswanathan at openjdk.org> wrote:

>> This pull request optimizes Vector API slice and unslice operations.
>> All the slice and unslice variants that take more than one argument are implemented in terms of already intrinsic methods on similar lines as slice(origin) and unslice(origin).
>> Also, the slice and unslice intrinsics for 256-bit byte/short vectors implemented for x86 platforms supporting AVX2 using a sequence of instructions.
>> 
>> For TestSlice.java attached to JBS (https://bugs.openjdk.java.net/browse/JDK-8259278):
>> Before:
>> Benchmark                                                       (size) Mode  Cnt    Score    Error   Units
>> TestSlice.vectorSliceOrigin                               1024  thrpt    5    17.665 ±  0.980  ops/ms
>> TestSlice.vectorSliceOriginVector                     1024  thrpt    5  604.179 ±  5.795  ops/ms
>> TestSlice.vectorSliceUnsliceOrigin                    1024  thrpt    5      9.286 ±  0.088  ops/ms
>> TestSlice.vectorSliceUnsliceOriginVector          1024  thrpt    5  435.678 ± 30.171 ops/ms
>> TestSlice.vectorSliceUnsliceOriginVectorPart    1024  thrpt    5  440.492 ± 24.592 ops/ms
>> 
>> After:
>> Benchmark                                                        (size)   Mode  Cnt     Score    Error   Units
>> TestSlice.vectorSliceOrigin                                1024  thrpt    5  1319.044 ± 67.862  ops/ms
>> TestSlice.vectorSliceOriginVector                      1024  thrpt    5    969.514 ± 33.411  ops/ms
>> TestSlice.vectorSliceUnsliceOrigin                     1024  thrpt    5    687.804 ± 31.511  ops/ms
>> TestSlice.vectorSliceUnsliceOriginVector           1024  thrpt    5    560.807 ± 20.600  ops/ms
>> TestSlice.vectorSliceUnsliceOriginVectorPart     1024  thrpt    5    560.202 ±  4.012  ops/ms
>> 
>> Please review.
>> 
>> Best Regards,
>> Sandhya
>
> Sandhya Viswanathan has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Use Objects.checkIndex and move code to xxxVector.java

Looks good.

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Marked as reviewed by vlivanov (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/1950