8319973: AArch64: Save and restore FPCR in the call stub

[theRealAph]

On AArch64 we don't save and restore the default floating-point control state when we enter and leave Java code. We really should, because if we're called via the JNI invocation interface with a weird FP control state we'll not be Java compatible.

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Progress

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Issue

• JDK-8319973: AArch64: Save and restore FPCR in the call stub (Bug - P3)

Reviewers

• Andrew Dinn (@adinn - Reviewer)
• Thomas Stuefe (@tstuefe - Reviewer)

Reviewing

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[openjdk]

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[mlbridge]

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• 00: Full (af4450bf)

[adinn]

All looks good.

[openjdk]

@theRealAph 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:

8319973: AArch64: Save and restore FPCR in the call stub

Reviewed-by: adinn, stuefe

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At the time when this comment was updated there had been 170 new commits pushed to the master branch:

• 04fd17e: 8320410: Reflow markdown in building.md
• 7f23110: 8319928: Exceptions thrown by cleanup actions should be handled correctly
• a6098e4: 8320280: RISC-V: Avoid passing t0 as temp register to MacroAssembler::lightweight_lock/unlock
• 60c8d9c: 8320300: Adjust hs_err output in malloc/mmap error cases
• 9f6a4a3: 8320386: Remove java/nio/channels/vthread/BlockingChannelOps.java#direct-register from ProblemList
• db1d823: 8320168: handle setsocktopt return values
• 6c5e15c: 8316557: Make fields final in 'sun.util' package
• de51aa1: 8283214: [macos] Screen magnifier does not show the magnified text for JcomboBox
• 179f505: 8320361: Doc error in RemoteRecordingStream.java
• 8ff7d6e: 8295391: Add discussion of binary <-> decimal conversion issues
• ... and 160 more: https://git.openjdk.org/jdk/compare/8fb94fd4fe46bc12885c7cc0c7ebbbc10fba47e5...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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[tstuefe]

Looks good, one question inline.

[tstuefe]

Why the 1-word gap? Alignment?

[theRealAph]

Yes, exactly. AArch64 stack is 16-aligned, and this is enforced by hardware.

[theRealAph]

/integrate

[openjdk]

Going to push as commit 6e86904.
Since your change was applied there have been 170 commits pushed to the master branch:

• 04fd17e: 8320410: Reflow markdown in building.md
• 7f23110: 8319928: Exceptions thrown by cleanup actions should be handled correctly
• a6098e4: 8320280: RISC-V: Avoid passing t0 as temp register to MacroAssembler::lightweight_lock/unlock
• 60c8d9c: 8320300: Adjust hs_err output in malloc/mmap error cases
• 9f6a4a3: 8320386: Remove java/nio/channels/vthread/BlockingChannelOps.java#direct-register from ProblemList
• db1d823: 8320168: handle setsocktopt return values
• 6c5e15c: 8316557: Make fields final in 'sun.util' package
• de51aa1: 8283214: [macos] Screen magnifier does not show the magnified text for JcomboBox
• 179f505: 8320361: Doc error in RemoteRecordingStream.java
• 8ff7d6e: 8295391: Add discussion of binary <-> decimal conversion issues
• ... and 160 more: https://git.openjdk.org/jdk/compare/8fb94fd4fe46bc12885c7cc0c7ebbbc10fba47e5...master

Your commit was automatically rebased without conflicts.

[openjdk]

@theRealAph Pushed as commit 6e86904.

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