RFR: 8331126: [s390x] secondary_super_cache does not scale well [v8]

[Amit Kumar]

> s390x Port for [JDK-8180450](https://bugs.openjdk.org/browse/JDK-8180450)
> 
> I ran `tier1` test with  `-XX:+UseSecondarySupersTable -XX:+VerifySecondarySupers -XX:+StressSecondarySupers` in fastdebug vm and didn't see any new failure appearing; Except one I have mentioned [here](https://github.com/openjdk/jdk/pull/19368#issuecomment-2154983693); But this is reproducible on every other architecture with these flags. 
> 
> 
> Without Patch: 
> 
> SecondarySuperCacheHits.test  avgt   15  0.929 ± 0.010  ns/op
> 
> SecondarySuperCacheInterContention.test     avgt   15  1.413 ± 0.007  ns/op
> SecondarySuperCacheInterContention.test:t1  avgt   15  1.415 ± 0.016  ns/op
> SecondarySuperCacheInterContention.test:t2  avgt   15  1.410 ± 0.017  ns/op
> 
> Benchmark                             Mode  Cnt   Score   Error  Units
> SecondarySupersLookup.testNegative00  avgt   15   1.806 ± 0.325  ns/op
> SecondarySupersLookup.testNegative01  avgt   15   2.364 ± 0.236  ns/op
> SecondarySupersLookup.testNegative02  avgt   15   2.903 ± 0.215  ns/op
> SecondarySupersLookup.testNegative03  avgt   15   3.417 ± 0.199  ns/op
> SecondarySupersLookup.testNegative04  avgt   15   3.758 ± 0.102  ns/op
> SecondarySupersLookup.testNegative05  avgt   15   4.352 ± 0.123  ns/op
> SecondarySupersLookup.testNegative06  avgt   15   4.800 ± 0.099  ns/op
> SecondarySupersLookup.testNegative07  avgt   15   5.365 ± 0.060  ns/op
> SecondarySupersLookup.testNegative08  avgt   15   6.316 ± 0.092  ns/op
> SecondarySupersLookup.testNegative09  avgt   15   6.669 ± 0.164  ns/op
> SecondarySupersLookup.testNegative10  avgt   15   7.041 ± 0.164  ns/op
> SecondarySupersLookup.testNegative16  avgt   15   9.336 ± 0.185  ns/op
> SecondarySupersLookup.testNegative20  avgt   15  11.373 ± 0.029  ns/op
> SecondarySupersLookup.testNegative30  avgt   15  15.236 ± 0.051  ns/op
> SecondarySupersLookup.testNegative32  avgt   15  16.031 ± 0.091  ns/op
> SecondarySupersLookup.testNegative40  avgt   15  19.197 ± 0.279  ns/op
> SecondarySupersLookup.testNegative50  avgt   15  23.804 ± 2.387  ns/op
> SecondarySupersLookup.testNegative55  avgt   15  25.610 ± 1.155  ns/op
> SecondarySupersLookup.testNegative56  avgt   15  26.128 ± 2.203  ns/op
> SecondarySupersLookup.testNegative57  avgt   15  26.126 ± 0.881  ns/op
> SecondarySupersLookup.testNegative58  avgt   15  26.314 ± 0.521  ns/op
> SecondarySupersLookup.testNegative59  avgt   15  26.750 ± 0.837  ns/op
> SecondarySupersLookup.testNegative60  avgt   15  27.118 ± 0.557  ns/op
> SecondarySupersLookup.testNegative61  avgt   15  27.763 ± 1.628  ns...

Amit Kumar has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains ten commits:

 - Merge branch 'master' into ssc_v0
 - comments from martin
 - add2reg -> z_la
 - comments from Lutz
 - Update src/hotspot/cpu/s390/macroAssembler_s390.cpp
 - rename: r_scratch to r_result in repne_scan method
 - Update src/hotspot/cpu/s390/macroAssembler_s390.cpp
 - Removes unused Labels & makes comment more sensible
 - [s390x] secondary super cache port

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

Changes: https://git.openjdk.org/jdk/pull/19544/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19544&range=07
  Stats: 431 lines in 5 files changed: 430 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/19544.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19544/head:pull/19544

PR: https://git.openjdk.org/jdk/pull/19544