RFR: 8267663: [vector] Add unsigned comparison operators on AArch64 [v3]

[Andrew Haley]

On Tue, 8 Jun 2021 13:46:35 GMT, Eric Liu <eliu at openjdk.org> wrote:

>> This patch implements unsigned vector comparison on AArch64. The
>> performance of unsigned comparison improves about 4x~5x in my local with
>> Byte128Vector.java[1].
>> 
>> Before:
>> Benchmark                               Score(op/ms)     Error
>> Byte128Vector.UNSIGNED_GE#size(1024)    99.953           6.17
>> Byte128Vector.UNSIGNED_GT#size(1024)    95.334           8.865
>> Byte128Vector.UNSIGNED_LE#size(1024)    76.908           24.332
>> Byte128Vector.UNSIGNED_LT#size(1024)    78.362           23.507
>> 
>> After:
>> Benchmark                               Score(op/ms)     Error
>> Byte128Vector.UNSIGNED_GE#size(1024)    421.809          25.57
>> Byte128Vector.UNSIGNED_GT#size(1024)    420.653          26.779
>> Byte128Vector.UNSIGNED_LE#size(1024)    316.754          92.889
>> Byte128Vector.UNSIGNED_LT#size(1024)    423.683          26.508
>> 
>> [Test]
>> - All vector API test cases passed without new failure. 8265312[2] has
>>   been implemented this on x86 and supplied sufficient test cases for
>>   all kinds of vector.
>> - No performance regression for other comparisons.
>> - libjvm.so drops off about 200KB after this patch by combining those
>>   vector compare rules.
>> 
>> [1] https://github.com/openjdk/panama-vector/blob/vectorIntrinsics/test/jdk/jdk/incubator/vector/benchmark/src/main/java/benchmark/jdk/incubator/vector/Byte128Vector.java#L1198
>> [2] https://github.com/openjdk/panama-vector/pull/68
>
> Eric Liu has updated the pull request incrementally with one additional commit since the last revision:
> 
>   small fix
>   
>   Change-Id: Iadff93a1d56647f9a21234af226b46492ad188e2

src/hotspot/cpu/aarch64/assembler_aarch64.cpp line 62:

> 60:     return _esize2arrangement_table[esize][isQ];
> 61: }
> 62: 

That's nice.

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PR: https://git.openjdk.java.net/jdk/pull/4358