8299323: Allow extended registers for cmpw

[fisk]

The current instruction encoder for cmpw(Address, int16_t) on x64 does not allow rex extended registers. Generational ZGC needs to use this for arbitrary registers. Let's add support for it instead of asserting the input Address uses a subset of registers.

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Progress

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Issue

• JDK-8299323: Allow extended registers for cmpw

Reviewers

• Sandhya Viswanathan (@sviswa7 - Reviewer)
• Vladimir Kozlov (@vnkozlov - Reviewer)

Reviewing

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[fisk]

/contributor add xmas92

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[mlbridge]

Webrevs

• 00: Full (9445fe23)

[sviswa7]

LGTM

[openjdk]

@fisk This change now passes all automated pre-integration checks.

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After integration, the commit message for the final commit will be:

8299323: Allow extended registers for cmpw

Reviewed-by: sviswanathan, kvn

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At the time when this comment was updated there had been 316 new commits pushed to the master branch:

• f52f6e6: 8299972: Remove metaprogramming/removeReference.hpp
• 4c1e66e: 8299971: Remove metaprogramming/conditional.hpp
• 4073b68: 8298047: Remove all non-significant trailing whitespace from properties files
• 506c818: 8296401: ConcurrentHashTable::bulk_delete might miss to delete some objects
• 319de6a: 8300124: Remove unnecessary assert in GenCollectedHeap::initialize
• 289aed4: 8298128: runtime/ErrorHandling/TestSigInfoInHsErrFile.java fails to find pattern with slowdebug
• a2f6766: 8288415: java/awt/PopupMenu/PopupMenuLocation.java is unstable in MacOS machines
• a734285: 8299879: CollectedHeap hierarchy should use override
• 98d75f1: 8299038: Add AArch64 backend support for auto-vectorized FP16 conversions
• cac72a6: 8300053: Shenandoah: Handle more GCCauses in ShenandoahControlThread::request_gc
• ... and 306 more: https://git.openjdk.org/jdk/compare/fa322e40b68abf0a253040d14414d41f4e01e028...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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[fisk]

Thanks for the review @sviswa7!

[fisk]

Any takers?

[vnkozlov]

Looks reasonable.
Did you verify that the code works when extended registers are used? It does match how we encode other 16bit instructions.

[fisk]

Thanks for the review, @vnkozlov! I did indeed check that the code generation is accurate for extended registers.

[fisk]

/integrate

[openjdk]

Going to push as commit b7fb8ef.
Since your change was applied there have been 327 commits pushed to the master branch:

• 07d5753: 8300168: Typo in AccessibleJTableHeaderEntry javadoc
• e82dc69: 8300205: Swing test bug8078268 make latch timeout configurable
• 9a36f8a: 8299673: Simplify object pinning interactions with string deduplication
• 3462438: 8299576: Reimplement java.io.Bits using VarHandle access
• f829a67: 8300227: [macos_aarch64] assert(cpu_has("hw.optional.arm.FEAT_AES")) failed after JDK-8297092
• 6a81d52: 8299213: Bad cast in GrowableArrayWithAllocator<>::grow
• 8365c67: 8300084: AquaFileChooserUI.getDefaultButton returns null
• 382fe51: 8163229: several regression tests have a main method that is never executed
• 06f9374: 8298867: Basics.java fails with SSL handshake exception
• 859ccd1: 8299847: RISC-V: Improve PrintOptoAssembly output of CMoveI/L nodes
• ... and 317 more: https://git.openjdk.org/jdk/compare/fa322e40b68abf0a253040d14414d41f4e01e028...master

Your commit was automatically rebased without conflicts.

[openjdk]

@fisk Pushed as commit b7fb8ef.

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