RFR: 8357554: Enable vectorization of Bool -> CMove with different type size (on riscv) [v4]

[Hamlin Li]

> Hi,
> 
> Can you help to review this patch?
> 
> This patch enables the vectorization of statement like `op_1 bop op_2 ? res_f_d_1 : res_f_d_2` in a loop, where op_x's size is different from res_f_d_x's.
> 
> To assist with code review, this pr contains only the shared code change, is splitted from https://github.com/openjdk/jdk/pull/28230, which enable & implement the riscv part. The similar optimization could be extended to other platforms. 
> 
> ## Some background
> 
> Previously, it's https://github.com/openjdk/jdk/pull/25336, which was blocked by unsigned comparison issue. The issue was recently resolved by https://github.com/openjdk/jdk/pull/27942, so I'm re-start working on this optimization.
> 
> This pr only relaxes one of the constraints in https://github.com/openjdk/jdk/pull/25336, i.e. transform CMoveF/D to vector operations no matter what's the size of comparison's operator, but remove the optimization of transform CMoveI/L to vector operations which I think need more investigation.
> 
> # Test
> ## Jtreg
> 
> in progress...
> 
> ## Performance
> 
> check the performance data in https://github.com/openjdk/jdk/pull/25341 on riscv.
> 
> Thanks

Hamlin Li 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 32 additional commits since the last revision:

 - Merge branch 'master' into vectorize-CMove-Bool
 - Merge branch 'openjdk:master' into master
 - Merge branch 'openjdk:master' into master
 - fix typo
 - Update src/hotspot/share/opto/superword.cpp
   
   refactor `is_velt_basic_type_compatible_use_def`
   
   Co-authored-by: Emanuel Peter <emanuel.peter at oracle.com>
 - comments
 - simplify
 - fix code path change in VectorNode::implemented
 - fix JDK-8371297: assert in BoolTest
 - revert supports_transform_cmove_to_vectorblend for all cpus
 - ... and 22 more: https://git.openjdk.org/jdk/compare/07be77ed...8e84017f

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/28231/files
  - new: https://git.openjdk.org/jdk/pull/28231/files/a89d26c4..8e84017f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=28231&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=28231&range=02-03

  Stats: 173302 lines in 1205 files changed: 118510 ins; 25624 del; 29168 mod
  Patch: https://git.openjdk.org/jdk/pull/28231.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28231/head:pull/28231

PR: https://git.openjdk.org/jdk/pull/28231