RFR: 8290322: Optimize Vector.rearrange over byte vectors for AVX512BW targets. [v3]

[Jatin Bhateja]

> Hi All,
> 
> Currently re-arrange over 512bit bytevector is optimized for targets supporting AVX512_VBMI feature, this patch generates efficient JIT sequence to handle it for AVX512BW targets.  Following performance results with newly added benchmark shows
> significant speedup.
> 
> System:  Intel(R) Xeon(R) Platinum 8280 CPU @ 2.70GHz (CascadeLake 28C 2S)
> 
> 
> Baseline:
> =========
> Benchmark                                     (size)   Mode  Cnt      Score   Error   Units
> RearrangeBytesBenchmark.testRearrangeBytes16     512  thrpt    2  16350.330          ops/ms
> RearrangeBytesBenchmark.testRearrangeBytes32     512  thrpt    2  15991.346          ops/ms
> RearrangeBytesBenchmark.testRearrangeBytes64     512  thrpt    2     34.423          ops/ms
> RearrangeBytesBenchmark.testRearrangeBytes8      512  thrpt    2  10873.348          ops/ms
> 
> 
> With-opt:
> =========
> Benchmark                                     (size)   Mode  Cnt      Score   Error   Units
> RearrangeBytesBenchmark.testRearrangeBytes16     512  thrpt    2  16062.624          ops/ms
> RearrangeBytesBenchmark.testRearrangeBytes32     512  thrpt    2  16028.494          ops/ms
> RearrangeBytesBenchmark.testRearrangeBytes64     512  thrpt    2   8741.901          ops/ms
> RearrangeBytesBenchmark.testRearrangeBytes8      512  thrpt    2  10983.226          ops/ms
> 
> 
> Kindly review and share your feedback.
> 
> Best Regards,
> Jatin

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 four additional commits since the last revision:

 - 8290322: Review comments resolution.
 - Merge branch 'master' of http://github.com/openjdk/jdk into JDK-8290322
 - Merge branch 'master' of http://github.com/openjdk/jdk into JDK-8290322
 - 8290322: Optimize Vector.rearrange over byte vectors for AVX512BW targets.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/9498/files
  - new: https://git.openjdk.org/jdk/pull/9498/files/71a8436e..61c83c91

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9498&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9498&range=01-02

  Stats: 20011 lines in 880 files changed: 11214 ins; 5561 del; 3236 mod
  Patch: https://git.openjdk.org/jdk/pull/9498.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9498/head:pull/9498

PR: https://git.openjdk.org/jdk/pull/9498