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8365153: AArch64: Set JVM flags for Neoverse N3 and V3 cores #26701

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@ruben-arm ruben-arm commented Aug 8, 2025

For Neoverse N1, N2, V1, and V2, the following JVM flags are set:

  • UseSIMDForMemoryOps=true
  • OnSpinWaitInst=isb
  • OnSpinWaitInstCount=1
  • AlwaysMergeDMB=false

Additionally, for Neoverse V1 and V2 only, these flags are set:

  • UseCryptoPmullForCRC32=true
  • CodeEntryAlignment=32

Set the same flags for Neoverse N3 and V3, respectively.


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  • Commit message must refer to an issue

Issue

  • JDK-8365153: AArch64: Set JVM flags for Neoverse N3 and V3 cores (Enhancement - P4)

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Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/26701/head:pull/26701
$ git checkout pull/26701

Update a local copy of the PR:
$ git checkout pull/26701
$ git pull https://git.openjdk.org/jdk.git pull/26701/head

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Checkout this PR locally:
$ git pr checkout 26701

View PR using the GUI difftool:
$ git pr show -t 26701

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Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/26701.diff

For Neoverse N1, N2, V1, and V2, the following JVM flags are set:
 - UseSIMDForMemoryOps=true
 - OnSpinWaitInst=isb
 - OnSpinWaitInstCount=1
 - AlwaysMergeDMB=false

Additionally, for Neoverse V1 and V2 only, these flags are set:
 - UseCryptoPmullForCRC32=true
 - CodeEntryAlignment=32

Set the same flags for Neoverse N3 and V3, respectively.
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bridgekeeper bot commented Aug 8, 2025

👋 Welcome back ruben-arm! 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.

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openjdk bot commented Aug 8, 2025

❗ This change is not yet ready to be integrated.
See the Progress checklist in the description for automated requirements.

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openjdk bot commented Aug 8, 2025

@ruben-arm The following label will be automatically applied to this pull request:

  • hotspot

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.

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