8351157: Clean up x86 GC barriers after 32-bit x86 removal

[shipilev]

Assembler GC barriers have quite a bit of coding to support 32-bit x86. As 32-bit x86 is removed, we can clean up those parts.

We can eliminate !LP64 blocks quite easily. We can also prune passing around thread argument, and just trust that r15_thread is always available.

Additional testing:

• Linux x86_64 server fastdebug, tier1
• Linux x86_64 server fastdebug, all

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Progress

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Issue

• JDK-8351157: Clean up x86 GC barriers after 32-bit x86 removal (Sub-task - P4)

Reviewers

• Kim Barrett (@kimbarrett - Reviewer)
• William Kemper (@earthling-amzn - Reviewer)
• Thomas Schatzl (@tschatzl - Reviewer)

Reviewing

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[bridgekeeper]

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[openjdk]

@shipilev 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:

8351157: Clean up x86 GC barriers after 32-bit x86 removal

Reviewed-by: kbarrett, wkemper, tschatzl

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

• bcac42a: 8349479: C2: when a Type node becomes dead, make CFG path that uses it unreachable
• 45b7c74: 8341641: Make %APPDATA% and %LOCALAPPDATA% env variables available in *.cfg files
• 5c438c5: 8352748: Remove com.sun.tools.classfile from the JDK
• ... and 22 more: https://git.openjdk.org/jdk/compare/250eb743c112fbcc45bf2b3ded1c644b19893577...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.

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[openjdk]

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[mlbridge]

Webrevs

• 02: Full (aa518904)
• 01: Full (76b25d7e)
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[kimbarrett]

Looks good.

[shipilev]

@tschatzl, @earthling-amzn -- want to look at G1 and Shenandoah parts, respectively?

[shipilev]

Friendly reminder :)

[kimbarrett]

Still looks good.

[earthling-amzn]

This is a nice simplification.

[shipilev]

@tschatzl -- are you fine with G1 cleanups?

[shipilev]

Thanks! I merged with current mainline locally, and there are no surprises. So I am integrating.

/integrate

[openjdk]

Going to push as commit 73c8c75.
Since your change was applied there have been 27 commits pushed to the master branch:

• c447a10: 8353856: Deprecate FlighRecorderPermission class for removal
• 4f80437: 8353842: C2: Add graph dumps before and after loop opts phase
• bcac42a: 8349479: C2: when a Type node becomes dead, make CFG path that uses it unreachable
• ... and 24 more: https://git.openjdk.org/jdk/compare/250eb743c112fbcc45bf2b3ded1c644b19893577...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit 73c8c75.

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