8293654: Improve SharedRuntime handling of continuation helper out-arguments

[shipilev]

(Found this while adapting current mainline to x86_32 port)

After JDK-8292584, we have gen_continuation_yield() that generates compiled entry, and implicitly uses the defaults for other ones (interpreter, exception). We should be more explicit about these, and verify the generators properly initialized all out-parameters.

I think we are only using interpreter/exception entry in enterContinuation, but not in yield. Notably, exception_offset should be -1 for nmethod::new_native_nmethod to treat it as "no exception handlers".

There a many ways to strengthen this, this PR is the one I like. I can do the symmetric change in aarch64, once we are agree on x86_64 version.

Additional testing:

• Linux x86_64 fastdebug, hotspot_loom jdk_loom
• Linux x86_64 fastdebug, tier1

---

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Issue

• JDK-8293654: Improve SharedRuntime handling of continuation helper out-arguments

Reviewers

• Dean Long (@dean-long - Reviewer) ⚠️ Review applies to f9101ab7
• Vladimir Kozlov (@vnkozlov - Reviewer)

Reviewing

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• 02: Full - Incremental (e0b244a3)
• 01: Full - Incremental (f187415f)
• 00: Full (f9101ab7)

[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:

8293654: Improve SharedRuntime handling of continuation helper out-arguments

Reviewed-by: dlong, kvn

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At the time when this comment was updated there had been 24 new commits pushed to the master branch:

• 7e02039: 8293647: Avoid unnecessary boxing in jdk.hotspot.agent
• 9039022: 8287394: AArch64: Remove cbuf parameter from far_call/far_jump/trampoline_call
• 1dc5039: 8293626: AccessFlag::locations(ClassFileFormatVersion cffv) does not throw NPEx when parameter is null
• 6f2223f: 8288180: C2: VectorPhase must ensure that SafePointNode memory input is a MergeMemNode
• 725f41f: 8293351: Add second tmp register to aarch64 BarrierSetAssembler::load_at
• 37234c8: 8291912: Introduce per-allocation target struct for members in G1PLABAllocator
• 1e1db5d: 8292591: Experimentally add back barrier-less Java thread transitions
• dfc16e0: 8292302: Windows GetLastError value overwritten by ThreadLocalStorage::thread
• 8bd79d3: 8170305: URLConnection doesn't handle HTTP/1.1 1xx (informational) messages
• 9cd3e35: 4834298: JFileChooser.getSelectedFiles() failed with multi-selection and double-click
• ... and 14 more: https://git.openjdk.org/jdk/compare/37df5f56259429482cfdbe38e8b6256f1efaf9e8...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.

[shipilev]

As promised, also added the symmetric AArch64 part. hotspot_loom jdk_loom passes there, running tier1 now.

[shipilev]

I think this one is pretty simple, but any other Reviews?

[vnkozlov]

Good.

[shipilev]

Thank you!

/integrate

[openjdk]

Going to push as commit 2baf251.
Since your change was applied there have been 26 commits pushed to the master branch:

• 60f59a4: 8293660: Fix frame::sender_for_compiled_frame frame size assert
• b3461c1: 8293680: PPC64BE build failure after JDK-8293344
• 7e02039: 8293647: Avoid unnecessary boxing in jdk.hotspot.agent
• 9039022: 8287394: AArch64: Remove cbuf parameter from far_call/far_jump/trampoline_call
• 1dc5039: 8293626: AccessFlag::locations(ClassFileFormatVersion cffv) does not throw NPEx when parameter is null
• 6f2223f: 8288180: C2: VectorPhase must ensure that SafePointNode memory input is a MergeMemNode
• 725f41f: 8293351: Add second tmp register to aarch64 BarrierSetAssembler::load_at
• 37234c8: 8291912: Introduce per-allocation target struct for members in G1PLABAllocator
• 1e1db5d: 8292591: Experimentally add back barrier-less Java thread transitions
• dfc16e0: 8292302: Windows GetLastError value overwritten by ThreadLocalStorage::thread
• ... and 16 more: https://git.openjdk.org/jdk/compare/37df5f56259429482cfdbe38e8b6256f1efaf9e8...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit 2baf251.

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