8361112: Use exact float -> Float16 conversion method in Float16 tests

[jddarcy]

Small test enhancement to make the test cases more robust to accidental rounding in float -> Float16 conversions.

A method with this functionality may be added to the API in the future (JDK-8341260).

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8361112: Use exact float -> Float16 conversion method in Float16 tests (Enhancement - P4)

Reviewers

• Raffaello Giulietti (@rgiulietti - Reviewer) Review applies to 7dec9f00
• Chen Liang (@liach - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/26055/head:pull/26055
$ git checkout pull/26055

Update a local copy of the PR:
$ git checkout pull/26055
$ git pull https://git.openjdk.org/jdk.git pull/26055/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 26055

View PR using the GUI difftool:
$ git pr show -t 26055

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/26055.diff

[bridgekeeper]

👋 Welcome back darcy! 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]

@jddarcy This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8361112: Use exact float -> Float16 conversion method in Float16 tests

Reviewed-by: liach, rgiulietti

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 25 new commits pushed to the master branch:

• c6448dc: 8361086: JVMCIGlobals::check_jvmci_flags_are_consistent has incorrect format string
• 1703915: 8361085: MemoryReserver log_on_large_pages_failure has incorrect format usage
• a910b20: 8346914: UB issue in scalbnA
• ... and 22 more: https://git.openjdk.org/jdk/compare/aa1911191cf8c2b855268a76baf0757909d66d1b...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[openjdk]

@jddarcy To determine the appropriate audience for reviewing this pull request, one or more labels corresponding to different subsystems will normally be applied automatically. However, no automatic labelling rule matches the changes in this pull request. In order to have an "RFR" email sent to the correct mailing list, you will need to add one or more applicable labels manually using the /label pull request command.

Applicable Labels

• build
• client
• compiler
• core-libs
• graal
• hotspot
• hotspot-compiler
• hotspot-gc
• hotspot-jfr
• hotspot-runtime
• i18n
• ide-support
• javadoc
• jdk
• jmx
• kulla
• net
• nio
• security
• serviceability
• shenandoah

[liach]

Suggested change

	if (Float.compare(f16.floatValue(), f) != 0 ) {
	if (Float.compare(f16.floatValue(), f) != 0) {