8296426: x86: Narrow UseAVX and UseSSE flags

[cl4es]

This patch narrows down the UseAVX and UseSSE flags to their actual supported range and uses int rather than intx for their type. This avoids need for some silly casts, and surprisingly has a small beneficial effect to binary size (-4kb libjvm on linux-x64)

This changes behavior of previously in-range values: -XX:UseAVX=4 would emit a strongly worded warning, but with the proposed change we'll instead terminate the JVM with an error similar to -XX:UseAVX=100. I believe this is too trivial for a CSR, since it only changes behavior for unsupported values.

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Issue

• JDK-8296426: x86: Narrow UseAVX and UseSSE flags

Reviewers

• Vladimir Ivanov (@iwanowww - Reviewer) ⚠️ Review applies to 38939310
• Vladimir Kozlov (@vnkozlov - Reviewer)

Reviewing

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[cl4es]

/label add hotspot-compiler

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[openjdk]

@cl4es
The hotspot-compiler label was successfully added.

[iwanowww]

Nice! Looks good.

[openjdk]

@cl4es 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:

8296426: x86: Narrow UseAVX and UseSSE flags

Reviewed-by: vlivanov, kvn

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:

• dd5d4df: 8295658: G1: Refactor G1SegmentedArray to indicate that it is an allocator
• cf65605: 8296445: C++ syntax error in jdwpTransport.h
• 1169dc0: 8296447: RISC-V: Make the operands order of vrsub_vx/vrsub_vi consistent with RVV 1.0 spec
• 4c80dff: 8296435: RISC-V: Small refactoring for increment/decrement
• 47d2c7b: 8295376: Improve debug agent virtual thread performance when no debugger is attached
• 76790ad: 8295673: Deprecate and disable legacy parallel class loading workaround for non-parallel-capable class loaders
• b6738c1: 8295663: Rephrase introduction to testing.md
• 7e85b41: 8296154: [macos] Change "/Applications" to "Applications" in DMG image
• 60db5f2: 8294020: improve errors for record declarations
• 520db1e: 8296485: BuildEEBasicConstraints.java test fails with SunCertPathBuilderException
• ... and 15 more: https://git.openjdk.org/jdk/compare/f857f795a9fc8b116bfc6b039114051061950e28...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.

[mlbridge]

Webrevs

• 02: Full - Incremental (781b4abd)
• 01: Full - Incremental (104b2234)
• 00: Full (38939310)

[vnkozlov]

You need to fix these flags type in JVMCI too. JVMCI tests failed.

[cl4es]

You need to fix these flags type in JVMCI too. JVMCI tests failed.

Fixed. Interestingly the only use of these that I could find assume the flags are int already (perhaps a misunderstanding of intx): https://github.com/openjdk/jdk/blob/master/src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.hotspot.amd64/src/jdk/vm/ci/hotspot/amd64/AMD64HotSpotVMConfig.java#L45

[vnkozlov]

Good.

[cl4es]

Thanks!
/integrate

[openjdk]

Going to push as commit d9b25e8.
Since your change was applied there have been 30 commits pushed to the master branch:

• 8146e1a: 8296347: Memory leak from ClassPathDirEntry::_dir
• 671f84b: 8296143: CertAttrSet's set/get mechanism is not type-safe
• d04d656: 8296433: Encountered null CLD while loading shared lambda proxy class
• 74f2b16: 8295303: cleanup debug agent's confusing use of EI_GC_FINISH
• 0ee25de: 8296504: Memory leak in G1PLABAllocator::PLABData
• dd5d4df: 8295658: G1: Refactor G1SegmentedArray to indicate that it is an allocator
• cf65605: 8296445: C++ syntax error in jdwpTransport.h
• 1169dc0: 8296447: RISC-V: Make the operands order of vrsub_vx/vrsub_vi consistent with RVV 1.0 spec
• 4c80dff: 8296435: RISC-V: Small refactoring for increment/decrement
• 47d2c7b: 8295376: Improve debug agent virtual thread performance when no debugger is attached
• ... and 20 more: https://git.openjdk.org/jdk/compare/f857f795a9fc8b116bfc6b039114051061950e28...master

Your commit was automatically rebased without conflicts.

[openjdk]

@cl4es Pushed as commit d9b25e8.

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