8359327: Incorrect AVX3Threshold results into code buffer overflows on APX targets

[jatin-bhateja]

As per the latest architecture-instruction-set-extensions-programming-reference manual version 57[1] , upcoming Diamond Rapids server with APX feature has a different CPU family ID (19) than prior Xeons (6).

Recently integrated EEVEX to REX2 demotion support with JDK-8351994 already handles this through a newly defined VM_Version::is_intel_server_family() API, but the existing AVX3Therehold setting is agnostic to this change, which causes code buffer overflows during arraycopy stubs generation.

Patch fixes this issue and also appropriately increments final code buffer size to prevent buffer overruns during stub generation with non zero AVX3Thereshold.

[1] https://www.intel.com/content/www/us/en/content-details/851355/intel-architecture-instruction-set-extensions-programming-reference.html?wapkw=intel%20architecture%20instruction%20set%20extensions%20programming%20reference

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Issue

• JDK-8359327: Incorrect AVX3Threshold results into code buffer overflows on APX targets (Bug - P3)(⚠️ The fixVersion in this issue is [25] but the fixVersion in .jcheck/conf is 26, a new backport will be created when this pr is integrated.)

Reviewers

• Sandhya Viswanathan (@sviswa7 - Reviewer)

Reviewing

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[bridgekeeper]

👋 Welcome back jbhateja! 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.

[jatin-bhateja]

/label add hotspot-compiler-dev

[openjdk]

@jatin-bhateja 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:

8359327: Incorrect AVX3Threshold results into code buffer overflows on APX targets

Reviewed-by: sviswanathan

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At the time when this comment was updated there had been 16 new commits pushed to the master branch:

• 523a4ef: 8358970: CounterMonitorMBean.getDerivedGaugeTimeStamp() JavaDoc incorrectly documents null
• 0dd7c69: 8357286: (bf) Remove obsolete instanceof checks in CharBuffer.append
• 66535fe: 8358701: Remove misleading javax.management.remote API doc wording about JMX spec, and historic link to JMXMP
• ... and 13 more: https://git.openjdk.org/jdk/compare/b6ec93b038c411d0c49be671c3b44dd231d01305...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.

[openjdk]

@jatin-bhateja
The hotspot-compiler label was successfully added.

[mlbridge]

Webrevs

• 00: Full (3ef8584b)

[sviswa7]

Looks good to me.

[jatin-bhateja]

-Xlog:stubs output before and after this patch. Array copy stubs use a 256-bit vector for non-zero AVX3Threshold, which results in a bulkier stub sequence and shows up in the final stub size.

Before Patch:-
[6.165s][info][stubs] StubRoutines (finalstubs) [0x00007fc74aac46e0, 0x00007fc74aad0f58] used: 31850, free: 19470

After Patch:-
[7.273s][info][stubs] StubRoutines (finalstubs) [0x00007fbf3308eee0, 0x00007fbf3309bf28] used: 26186, free: 27134

The above analysis is done using SDE version 9.57 (internally available)

[jatin-bhateja]

/integrate

[openjdk]

Going to push as commit e7f63ba.
Since your change was applied there have been 23 commits pushed to the master branch:

• a0fb35c: 8359272: Several vmTestbase/compact tests timed out on large memory machine
• 032ead1: 8358483: G1: Remove G1HeapRegionManager::num_available_regions
• a8b4284: 8359293: Make TestNoNULL extensible
• ... and 20 more: https://git.openjdk.org/jdk/compare/b6ec93b038c411d0c49be671c3b44dd231d01305...master

Your commit was automatically rebased without conflicts.

[openjdk]

@jatin-bhateja Pushed as commit e7f63ba.

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