8252188: Crash in OrINode::Ideal(PhaseGVN*, bool)+0x8b9

[vnkozlov]

Code added by 8248830 uses Node::is_Con() check when looking for constant shift values.

Unfortunately it does not guarantee that it will be Integer constant because TOP node is also ConNode. I used C2 types to check and get shift values. I also refactor code to consolidate checks.

Method degenerate_vector_rotate() in vectornode.cpp has is_Con() check and, in general, it could be TOP because we do loop optimizations after vectorization. I added isa_int() check and treat 'cnt' in other case as variable to do transformation on 'else' branch and let sub-graph collapse there. I also refactor degenerate_vector_rotate() to make it compact.

I removed OrVNode::Ideal() method added by 8248830 because it is currently not used (it is for Vector API). And its code is convoluted and does not match code in OrINode::Ideal().

I moved Rotate vectorization tests into new test files TestIntVectRotate.java and TestLongVectRotate.java and added more tests methods for which vectors are created.

Tested: tier1, hs-tier2, hs-tier3.
Verified fix with replay file from bug report.
I also checked that RotateBenchmark.java added by 8248830 still creates Rotate vectors after this fix.

I created subtask to add new regerssion test later because this fix is urgent and I did not have time to prepare it.

The fix was already reviewed on mailing list https://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2020-September/039886.html

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Progress

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Issue

• JDK-8252188: Crash in OrINode::Ideal(PhaseGVN*, bool)+0x8b9

Reviewers

• Vladimir Ivanov (@iwanowww - Reviewer)
• thartmann - Reviewer ⚠️ Added manually
• jbhateja - Committer ⚠️ Added manually

Download

$ git fetch https://git.openjdk.java.net/jdk pull/262/head:pull/262
$ git checkout pull/262

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[vnkozlov]

/reviewer credit thartmann
/reviewer credit vlivanov

[openjdk]

@vnkozlov
Reviewer thartmann successfully credited.

[openjdk]

@vnkozlov
Reviewer vlivanov successfully credited.

[vnkozlov]

/reviewer credit jbhateja

[openjdk]

@vnkozlov
Reviewer jbhateja successfully credited.

[mlbridge]

Webrevs

• 00: Full (32a6854)

[iwanowww]

Looks good.

[openjdk]

@vnkozlov This change now passes all automated pre-integration checks. In addition to the automated checks, the change must also fulfill all project specific requirements

After integration, the commit message will be:

8252188: Crash in OrINode::Ideal(PhaseGVN*, bool)+0x8b9

Reviewed-by: vlivanov, thartmann, jbhateja

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Since the source branch of this PR was last updated there have been 2 commits pushed to the master branch:

• 224a30f: 8252311: AArch64: save two words in itable lookup stub
• 22f7af7: 8253317: The "com/apple/eawt" is missed in the "othervm.dirs" config option

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid automatic rebasing, please merge master into your branch, and then specify the current head hash when integrating, like this: /integrate 224a30f12ce27257af94e2607c53e5f59ac2bd0f.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[vnkozlov]

/integrate

[openjdk]

@vnkozlov Since your change was applied there have been 2 commits pushed to the master branch:

• 224a30f: 8252311: AArch64: save two words in itable lookup stub
• 22f7af7: 8253317: The "com/apple/eawt" is missed in the "othervm.dirs" config option

Your commit was automatically rebased without conflicts.

Pushed as commit 1438ce0.

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