8363910: Avoid tuning for Power10 CPUs on Linux ppc64le when gcc < 10 is used

[MBaesken]

Older gcc version (8, 9) do not support the -mtune=power10 flag. We should set this only when recent gcc versions are used.

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Issue

• JDK-8363910: Avoid tuning for Power10 CPUs on Linux ppc64le when gcc < 10 is used (Bug - P4)

Reviewers

• Thomas Stuefe (@tstuefe - Reviewer)

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👋 Welcome back mbaesken! 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.

[openjdk]

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

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

8363910: Avoid tuning for Power10 CPUs on Linux ppc64le when gcc < 10 is used

Reviewed-by: stuefe

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At the time when this comment was updated there had been 24 new commits pushed to the master branch:

• 518d5f4: 8361871: [GCC static analyzer] complains about use of uninitialized value ckpObject in p11_util.c
• f79bd54: 8362882: Update SubmissionPublisher() specification to reflect use of ForkJoinPool.asyncCommonPool()
• 52155db: 8364082: jdk/jfr/event/gc/heapsummary/TestHeapSummaryEventPSParOld.java Eden should be placed first in young
• ... and 21 more: https://git.openjdk.org/jdk/compare/e6ac956a7ac613b916c0dbfda7e57856c1b8a83c...master

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[mlbridge]

Webrevs

• 00: Full (ddc2c047)

[MBaesken]

@jerboaa is that what you would like to have ?

[RealLucy]

Just for my understanding:
If -mtune=power10 is already in the arguments, nothing is changed/added. In any other case (e.g. -mtune=power11), the string -mtune=power8 is added. Is that intended?

[MBaesken]

Just for my understanding: If -mtune=power10 is already in the arguments, nothing is changed/added. In any other case (e.g. -mtune=power11), the string -mtune=power8 is added. Is that intended?

We do not set '-mtune=power11' , just power10 (default for recent gcc versions) and for old ones where it is not supported (like gcc8) now with this change power8.
In case the user brings in own -mtune=power<x> settings via additional c/cxx flags set by configure , it is up to the user to set them at the right place to overwrite the default .

[tstuefe]

Very good, this helps our CI errors.

/Thomas

[MBaesken]

Thanks for the review !

/integrate

[openjdk]

Going to push as commit 41c94ee.
Since your change was applied there have been 24 commits pushed to the master branch:

• 518d5f4: 8361871: [GCC static analyzer] complains about use of uninitialized value ckpObject in p11_util.c
• f79bd54: 8362882: Update SubmissionPublisher() specification to reflect use of ForkJoinPool.asyncCommonPool()
• 52155db: 8364082: jdk/jfr/event/gc/heapsummary/TestHeapSummaryEventPSParOld.java Eden should be placed first in young
• ... and 21 more: https://git.openjdk.org/jdk/compare/e6ac956a7ac613b916c0dbfda7e57856c1b8a83c...master

Your commit was automatically rebased without conflicts.

[openjdk]

@MBaesken Pushed as commit 41c94ee.

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