RFR: 8344232: [PPC64] secondary_super_cache does not scale well: C1 and interpreter [v2]

[Martin Doerr]

> PPC64 implementation of https://github.com/openjdk/jdk/commit/ead0116f2624e0e34529e47e4f509142d588b994. I have implemented a couple of rotate instructions.
> The first commit only implements `lookup_secondary_supers_table_var` and uses it in C2. The second commit makes the changes to use it in the interpreter, runtime and C1.
> C1 part is refactored such that the same code as before this patch is generated when `UseSecondarySupersTable` is disabled. Some stubs are modified to provide one more temp register.
> 
> Performance difference can be observed when C2 is disabled (measured on Power10):
> 
> 
> -XX:TieredStopAtLevel=1 -XX:-UseSecondarySupersTable:
> SecondarySuperCacheHits.test  avgt   15  13.028 ± 0.005  ns/op
> SecondarySuperCacheInterContention.test     avgt   15  417.746 ± 19.046  ns/op
> SecondarySuperCacheInterContention.test:t1  avgt   15  417.852 ± 17.814  ns/op
> SecondarySuperCacheInterContention.test:t2  avgt   15  417.641 ± 23.431  ns/op
> SecondarySuperCacheIntraContention.test  avgt   15  340.995 ± 5.620  ns/op
> 
> 
> 
> -XX:TieredStopAtLevel=1 -XX:+UseSecondarySupersTable:
> SecondarySuperCacheHits.test  avgt   15  14.539 ± 0.002  ns/op
> SecondarySuperCacheInterContention.test     avgt   15  25.667 ± 0.576  ns/op
> SecondarySuperCacheInterContention.test:t1  avgt   15  25.709 ± 0.655  ns/op
> SecondarySuperCacheInterContention.test:t2  avgt   15  25.626 ± 0.820  ns/op
> SecondarySuperCacheIntraContention.test  avgt   15  22.466 ± 1.554  ns/op
> 
> 
> `SecondarySuperCacheHits` seems to be slightly slower, but `SecondarySuperCacheInterContention` and `SecondarySuperCacheIntraContention` are much faster (when C2 is disabled).

Martin Doerr has updated the pull request incrementally with one additional commit since the last revision:

  Remove early return from check_klass_subtype_slow_path.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/22881/files
  - new: https://git.openjdk.org/jdk/pull/22881/files/f7c1b79c..37789b38

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22881&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22881&range=00-01

  Stats: 13 lines in 2 files changed: 5 ins; 4 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/22881.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22881/head:pull/22881

PR: https://git.openjdk.org/jdk/pull/22881