RFR: 8342393: Promote commutative vector IR node sharing [v2]

[Jatin Bhateja]

> Patch promotes the sharing of commutative vector IR with the same inputs but different input ordering.
> Unlike scalar IR where we perform edge swapping by [sorting inputs](https://github.com/openjdk/jdk/blob/master/src/hotspot/share/opto/addnode.cpp#L122) based on node indices during IR idealization, for vector IR we chose a simpler approach to decorate commutative operations with a special node-level flag during IR construction thus
> obviating any dependency on explicit idealization routines. This flag is later used during GVN hashing to enable node sharing.  
> 
> Following are the performance stats for JMH included with the patch.
> 
> 
> Granite Rapids (P-core Xeon Server)
> Baseline : 
> Benchmark                                                                (size)   Mode  Cnt      Score   Error   Units
> VectorCommutativeOperSharingBenchmark.commutativeByteOperationShairing     1024  thrpt    2   8982.549          ops/ms
> VectorCommutativeOperSharingBenchmark.commutativeIntOperationShairing      1024  thrpt    2   6072.773          ops/ms
> VectorCommutativeOperSharingBenchmark.commutativeLongOperationShairing     1024  thrpt    2   2368.856          ops/ms
> VectorCommutativeOperSharingBenchmark.commutativeShortOperationShairing    1024  thrpt    2  15215.087          ops/ms
> 
> Withopt:
> Benchmark                                                                (size)   Mode  Cnt      Score   Error   Units
> VectorCommutativeOperSharingBenchmark.commutativeByteOperationShairing     1024  thrpt    2  11963.554          ops/ms
> VectorCommutativeOperSharingBenchmark.commutativeIntOperationShairing      1024  thrpt    2   7036.088          ops/ms
> VectorCommutativeOperSharingBenchmark.commutativeLongOperationShairing     1024  thrpt    2   2906.731          ops/ms
> VectorCommutativeOperSharingBenchmark.commutativeShortOperationShairing    1024  thrpt    2  17148.131          ops/ms
> 
> Sierra Forest (E-core Xeon Server)
> Baseline:
> Benchmark                                                                (size)   Mode  Cnt     Score   Error   Units
> VectorCommutativeOperSharingBenchmark.commutativeByteOperationShairing     1024  thrpt    2  2444.359          ops/ms
> VectorCommutativeOperSharingBenchmark.commutativeIntOperationShairing      1024  thrpt    2  1710.256          ops/ms
> VectorCommutativeOperSharingBenchmark.commutativeLongOperationShairing     1024  thrpt    2   308.766          ops/ms
> VectorCommutativeOperSharingBenchmark.commutativeShortOperationShairing    1024  thrpt    2  390...

Jatin Bhateja has updated the pull request incrementally with one additional commit since the last revision:

  removing spaces

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/22863/files
  - new: https://git.openjdk.org/jdk/pull/22863/files/21b2ffd8..f42645a1

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22863&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22863&range=00-01

  Stats: 5 lines in 2 files changed: 0 ins; 5 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/22863.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22863/head:pull/22863

PR: https://git.openjdk.org/jdk/pull/22863