8311220: Optimization for StringLatin UpperLower

[wkia]

This is backport of "JDK-8311220 Optimization for StringLatin UpperLower"

It seems good to have it backported as I see improvements even locally on my i7-12700H (benchmarks command line was taken from original PR):

sh make/devkit/createJMHBundle.sh
bash configure --with-jmh=build/jmh/jars
make test TEST="micro:java.lang.StringUpperLower.*"

----- Baseline JDK21
Benchmark                      Mode  Cnt   Score   Error  Units
StringUpperLower.lowerToLower  avgt   15  24.146 ± 0.216  ns/op
StringUpperLower.lowerToUpper  avgt   15  43.720 ± 2.689  ns/op
StringUpperLower.mixedToLower  avgt   15  27.335 ± 1.120  ns/op
StringUpperLower.mixedToUpper  avgt   15  43.239 ± 3.731  ns/op
StringUpperLower.upperToLower  avgt   15  28.310 ± 1.557  ns/op
StringUpperLower.upperToUpper  avgt   15  35.032 ± 1.840  ns/op

----- Backported
Benchmark                      Mode  Cnt   Score   Error  Units
StringUpperLower.lowerToLower  avgt   15  13.890 ± 0.786  ns/op
StringUpperLower.lowerToUpper  avgt   15  38.636 ± 2.103  ns/op
StringUpperLower.mixedToLower  avgt   15  28.087 ± 1.639  ns/op
StringUpperLower.mixedToUpper  avgt   15  33.970 ± 0.502  ns/op
StringUpperLower.upperToLower  avgt   15  28.394 ± 1.443  ns/op
StringUpperLower.upperToUpper  avgt   15  17.347 ± 0.578  ns/op

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8311220 needs maintainer approval

Issue

• JDK-8311220: Optimization for StringLatin UpperLower (Enhancement - P4 - Requested)

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[bridgekeeper]

👋 Welcome back rmarchenko! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

❗ This change is not yet ready to be integrated.
See the Progress checklist in the description for automated requirements.

[openjdk]

This backport pull request has now been updated with issue from the original commit.

[openjdk]

⚠️ @wkia This change is now ready for you to apply for maintainer approval. This can be done directly in each associated issue or by using the /approval command.

[mlbridge]

Webrevs

• 00: Full (b3f2f5d5)

[openjdk]

@wkia
8311220: The approval request has been created successfully.

[wkia]

/approval request This is backport of JDK-8311220. Clean backport. All checks are passed. It'd be good to backport this as I see improvements even locally.

[openjdk]

@wkia
8311220: The approval request was already up to date.