8264063: Outer Safepoint poll load should not reference the head of inner strip mined loop.

[vnkozlov]

When loop is "strip mined" polling address load (parse1.cpp#L2280) should be cloned together with safepoint node and pinned outside inner loop. Otherwise we have issues like 8263352

I also remove leftover (unused needs_polling_address_input() method) from 8220051 changes.

Tested hs-tier1-4

---

Progress

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Issue

• JDK-8264063: Outer Safepoint poll load should not reference the head of inner strip mined loop.

Reviewers

• Roland Westrelin (@rwestrel - Reviewer)
• Vladimir Ivanov (@iwanowww - Reviewer)

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[bridgekeeper]

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[openjdk]

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

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[mlbridge]

Webrevs

• 01: Full - Incremental (58a4ce1d)
• 00: Full (1f645337)

[pfustc]

Should we also remove below part of code in loopTransform.cpp in this patch?

3704         if (n->is_CountedLoop() && n->as_CountedLoop()->is_strip_mined()) {
3705           // In strip-mined counted loops, the CountedLoopNode may be
3706           // used by the address polling node of the outer safepoint.
3707           // Skip this use because it's safe.
3708           Node* sfpt = n->as_CountedLoop()->outer_safepoint();
3709           Node* polladr = sfpt->in(TypeFunc::Parms+0);
3710           if (use == polladr) {
3711             continue;
3712           }
3713         }

[vnkozlov]

Should we also remove below part of code in loopTransform.cpp in this patch?

3704         if (n->is_CountedLoop() && n->as_CountedLoop()->is_strip_mined()) {
3705           // In strip-mined counted loops, the CountedLoopNode may be
3706           // used by the address polling node of the outer safepoint.
3707           // Skip this use because it's safe.
3708           Node* sfpt = n->as_CountedLoop()->outer_safepoint();
3709           Node* polladr = sfpt->in(TypeFunc::Parms+0);
3710           if (use == polladr) {
3711             continue;
3712           }
3713         }

I thought that it does not harm to have this code but on other hand it will be not executed anymore.
I will removed it and I will run ArrayFill.java to make sure optimization works with strip mined loops.

[vnkozlov]

I removed pointed code and verified that arrayfill optimization still works with strip mined loops.

[rwestrel]

Looks good to me.

[openjdk]

@vnkozlov 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:

8264063: Outer Safepoint poll load should not reference the head of inner strip mined loop.

Reviewed-by: roland, vlivanov

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 25 new commits pushed to the master branch:

• af13c64: 8264711: More runtime TRAPS cleanups
• 3aec2d9: 8264718: Shenandoah: enable string deduplication during root scanning
• 255afbe: 8264672: runtime/ParallelLoad/ParallelSuperTest.java timed out
• ec599da: 8264633: Add missing logging to PlatformRecording#stop
• e89542f: 8264352: AArch64: Optimize vector "not/andNot" for NEON and SVE
• 016db40: 8263907: Specification of CellRendererPane::paintComponent(..Rectangle) should clearly mention which method it delegates the call to
• 78d1164: 8214455: Relocate CDS archived regions to the top of the G1 heap
• 88eb291: 8264809: test-lib fails to build due to some warnings in ASN1Formatter and jfr
• a863ab6: 8264551: Unexpected warning when jpackage creates an exe
• 6e2b82a: 8264731: Introduce InstanceKlass::method_at_itable_or_null()
• ... and 15 more: https://git.openjdk.java.net/jdk/compare/4bb80f3720936d0cd9836e4f9c7233d2b4d8eee3...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.

[iwanowww]

Looks good.

[vnkozlov]

Thank you Vladimir and Roland.

[vnkozlov]

/integrate

[openjdk]

@vnkozlov Since your change was applied there have been 27 commits pushed to the master branch:

• 04fa1ed: 8264848: [macos] libjvm.dylib linker warning due to macOS version mismatch
• 214d6e2: 8263506: Make sun.net.httpserver.UnmodifiableHeaders unmodifiable
• af13c64: 8264711: More runtime TRAPS cleanups
• 3aec2d9: 8264718: Shenandoah: enable string deduplication during root scanning
• 255afbe: 8264672: runtime/ParallelLoad/ParallelSuperTest.java timed out
• ec599da: 8264633: Add missing logging to PlatformRecording#stop
• e89542f: 8264352: AArch64: Optimize vector "not/andNot" for NEON and SVE
• 016db40: 8263907: Specification of CellRendererPane::paintComponent(..Rectangle) should clearly mention which method it delegates the call to
• 78d1164: 8214455: Relocate CDS archived regions to the top of the G1 heap
• 88eb291: 8264809: test-lib fails to build due to some warnings in ASN1Formatter and jfr
• ... and 17 more: https://git.openjdk.java.net/jdk/compare/4bb80f3720936d0cd9836e4f9c7233d2b4d8eee3...master

Your commit was automatically rebased without conflicts.

Pushed as commit 81d35e4.

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