RFR: 8302906: AArch64: Add SVE backend support for vector unsigned comparison [v5]

[Eric Liu]

On Wed, 15 Mar 2023 03:48:01 GMT, changpeng1997 <duke at openjdk.org> wrote:

>> This patch implements unsigned vector comparison on SVE.
>> 
>> 1: Test:
>> All vector API test cases[1][2] passed without new failure. Existing test cases can cover all unsigned comparison conditions for all kinds of vector.
>> 
>> 2: Performance:
>> (1): Benchmark:
>> As existing benchmarks in panama repo (such as [3]) have some issues [4] (We will fix them in a separate patch.), I collected performance data with a reduced jmh benchmark [5]. e.g. for ByteVector unsigned comparison:
>> 
>> 
>> @Benchmark
>>     public void byteVectorUnsignedCompare() {
>>         for (int j = 0; j < 200; j++) {
>>             for (int i = 0; i < bspecies.length(); i++) {
>>                 ByteVector av = ByteVector.fromArray(bspecies, ba, i);
>>                 ByteVector ca = ByteVector.fromArray(bspecies, bb, i);
>>                 av.compare(VectorOperators.UNSIGNED_GT, ca).intoArray(br, i);
>>             }
>>         }
>>     }
>> 
>> 
>> (2): Performance data
>> 
>> Before:
>> 
>> 
>> Benchmark                               Score(op/ms)     Error
>> ByteVector.UNSIGNED_GT#size(1024)       4.846            3.419
>> ShortVector.UNSIGNED_GE#size(1024)      3.055            1.369
>> IntVector.UNSIGNED_LT#size(1024)        3.475            1.269
>> LongVector.UNSIGNED_LE#size(1024)       4.515            1.812
>> 
>> 
>> After:
>> 
>> 
>> Benchmark                               Score(op/ms)     Error
>> ByteVector.UNSIGNED_GT#size(1024)       493.937          1.389
>> ShortVector.UNSIGNED_GE#size(1024)      5308.796         20.557
>> IntVector.UNSIGNED_LT#size(1024)        4944.744         10.606
>> LongVector.UNSIGNED_LE#size(1024)       8459.605         28.683
>> 
>> 
>> [1] https://github.com/openjdk/jdk/tree/master/test/jdk/jdk/incubator/vector
>> [2] https://github.com/openjdk/jdk/tree/master/test/hotspot/jtreg/compiler/vectorapi
>> [3] https://github.com/openjdk/panama-vector/blob/2aade73adeabdf6a924136b17fd96ccc95c1d160/test/micro/org/openjdk/bench/jdk/incubator/vector/operation/ByteMaxVector.java#L1459
>> [4] https://bugs.openjdk.org/browse/JDK-8282850
>> [5] https://gist.github.com/changpeng1997/d311127e1015c107197f9b56a92b0fae
>
> changpeng1997 has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Move cm() and fcm() to advsimd-three-same section.

LGTM

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

Marked as reviewed by eliu (Committer).

PR: https://git.openjdk.org/jdk/pull/12725