8293996: C2: fix and simplify IdealLoopTree::do_remove_empty_loop

[TobiHartmann]

Backport of JDK-8293996. Applies cleanly. Approval is pending.

Thanks,
Tobias

---

Progress

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Issue

• JDK-8293996: C2: fix and simplify IdealLoopTree::do_remove_empty_loop

Reviewing

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[bridgekeeper]

👋 Welcome back thartmann! 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 backport pull request has now been updated with issue from the original commit.

[openjdk]

@TobiHartmann 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:

8293996: C2: fix and simplify IdealLoopTree::do_remove_empty_loop

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[mlbridge]

Webrevs

• 00: Full (25164c51)

[TobiHartmann]

/integrate

[openjdk]

Going to push as commit 62db7bb.
Since your change was applied there have been 2 commits pushed to the master branch:

• c8082a3: 8296771: RISC-V: C2: assert(false) failed: bad AD file
• 2adc3e1: 8295414: [Aarch64] C2: assert(false) failed: bad AD file

Your commit was automatically rebased without conflicts.

[openjdk]

@TobiHartmann Pushed as commit 62db7bb.

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