8256203: Simplify RegMask::Empty

[cl4es]

• Simplify RegMask::Empty to use default constructor.
• Add missing validation in the empty constructor.

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• Change must be properly reviewed

Testing

	Linux x64	Linux x86	Windows x64	macOS x64
Build	✔️ (5/5 passed)	✔️ (2/2 passed)	✔️ (2/2 passed)	✔️ (2/2 passed)
Test (tier1)	✔️ (9/9 passed)	✔️ (9/9 passed)	✔️ (9/9 passed)	✔️ (9/9 passed)

Issue

• JDK-8256203: Simplify RegMask::Empty

Reviewers

• Tobias Hartmann (@TobiHartmann - Reviewer)
• Christian Hagedorn (@chhagedorn - Reviewer)

Download

$ git fetch https://git.openjdk.java.net/jdk pull/1167/head:pull/1167
$ git checkout pull/1167

[bridgekeeper]

👋 Welcome back redestad! 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]

@cl4es The following label will be automatically applied to this pull request:

• hotspot-compiler

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.

[mlbridge]

Webrevs

• 00: Full (f0f901b)

[TobiHartmann]

Looks good to me.

[openjdk]

@cl4es 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:

8256203: Simplify RegMask::Empty

Reviewed-by: thartmann, chagedorn

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 13 new commits pushed to the master branch:

• ec08b3f: 8256188: Adjust output of make/autoconf/configure
• da48003: 8255975: Fix AArch64 OpenJDK build failure with gcc-5
• 14e25e2: 8255982: Extend BasicJMapTest to test with different GC Heap
• 2f06893: 8252526: Remove excessive inclusion of jvmti.h and jvmtiExport.hpp
• ccb48b7: 8248188: Add IntrinsicCandidate and API for Base64 decoding
• 59965c1: 8256237: Zero: non-PCH build fails after JDK-8253064
• bfa060f: 8256051: nmethod_entry_barrier stub miscalculates xmm spill size on x86_32
• 96e0261: 8256106: Bypass intrinsic/barrier when calling Reference.get() from Finalizer
• 3c3469b: 8256020: Shenandoah: Don't resurrect objects during evacuation on AS_NO_KEEPALIVE
• 2e19026: 8253064: monitor list simplifications and getting rid of TSM
• ... and 3 more: https://git.openjdk.java.net/jdk/compare/ed615e3ca0d681e8e67cdbf1d5d964979ccd7888...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.

[chhagedorn]

Looks good!

[cl4es]

@TobiHartmann @chhagedorn - thank you for reviewing!

/integrate

[openjdk]

@cl4es Since your change was applied there have been 16 commits pushed to the master branch:

• 70c7b1d: 8250607: C2: Filter type in PhiNode::Value() for induction variables of trip-counted integer loops
• bd8693a: 8256181: Remove Allocation of old generation on alternate memory devices functionality
• 4df8abc: 8255787: Tag container tests that use cGroups with cgroups keyword
• ec08b3f: 8256188: Adjust output of make/autoconf/configure
• da48003: 8255975: Fix AArch64 OpenJDK build failure with gcc-5
• 14e25e2: 8255982: Extend BasicJMapTest to test with different GC Heap
• 2f06893: 8252526: Remove excessive inclusion of jvmti.h and jvmtiExport.hpp
• ccb48b7: 8248188: Add IntrinsicCandidate and API for Base64 decoding
• 59965c1: 8256237: Zero: non-PCH build fails after JDK-8253064
• bfa060f: 8256051: nmethod_entry_barrier stub miscalculates xmm spill size on x86_32
• ... and 6 more: https://git.openjdk.java.net/jdk/compare/ed615e3ca0d681e8e67cdbf1d5d964979ccd7888...master

Your commit was automatically rebased without conflicts.

Pushed as commit f7685a4.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.