8223363: Bad node estimate assertion failure

[TheRealMDoerr]

Backport of JDK-8223363 (including JDK-8223502 and JDK-8224648 as in original commit)
loopTransform.cpp (introduction of policy_unswitching and policy_maximally_unroll) and loopnode.hpp required manual integration. Rest applies cleanly.

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• Change must be properly reviewed

Issues

• JDK-8223363: Bad node estimate assertion failure
• JDK-8223502: Node estimate for loop unswitching is not correct: assert(delta <= 2 * required) failed: Bad node estimate
• JDK-8224648: assert(!exceeding_node_budget()) failed: Too many NODES required! failure with ctw

Reviewers

• Goetz Lindenmaier (@GoeLin - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/jdk11u-dev pull/874/head:pull/874
$ git checkout pull/874

Update a local copy of the PR:
$ git checkout pull/874
$ git pull https://git.openjdk.java.net/jdk11u-dev pull/874/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 874

View PR using the GUI difftool:
$ git pr show -t 874

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/jdk11u-dev/pull/874.diff

[bridgekeeper]

👋 Welcome back mdoerr! 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]

This backport pull request has now been updated with issues and summary from the original commit.

[mlbridge]

Webrevs

• 00: Full (fbd616ba)

[GoeLin]

LGTM. Differences are only minimal.

[GoeLin]

Pre-submit failures: missing dependencies; unrelated.

[openjdk]

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

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

8223363: Bad node estimate assertion failure
8223502: Node estimate for loop unswitching is not correct: assert(delta <= 2 * required) failed: Bad node estimate
8224648: assert(!exceeding_node_budget()) failed: Too many NODES required! failure with ctw

Tighten the node estimates. New est_loop_clone_sz() implementation that will compute a "fan-out" complexity estimate as part of the size estimate (to better estimate complex loop body size after cloning). New est_loop_unroll_sz() function, used to estimate the size of a loop body att full/maximal unrolling. Correction to node budget final tests and asserts.

Reviewed-by: goetz

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 7 new commits pushed to the master branch:

• 1123120: 8279668: x86: AVX2 versions of vpxor should be asserted
• 39974dc: 8186548: move jdk.testlibrary.JcmdBase closer to tests
• 50ac138: 8210022: remove jdk.testlibrary.ProcessThread, TestThread and XRun
• 9d3c940: 8218751: Do not store original classfiles inside the CDS archive
• 51b45e7: 8282589: runtime/ErrorHandling/ErrorHandler.java fails on MacOS aarch64 in jdk 11
• 8770332: 8208697: vmTestbase/metaspace/stressHierarchy/stressHierarchy012/TestDescription.java fails with OutOfMemoryError: Metaspace
• 7d16719: 8212151: jdi/ExclusiveBind.java times out due to "bind failed: Address already in use" on Solaris-X64

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
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.

[TheRealMDoerr]

Thanks for the review and the approval!
/integrate

[openjdk]

Going to push as commit 5f40afc.
Since your change was applied there have been 7 commits pushed to the master branch:

• 1123120: 8279668: x86: AVX2 versions of vpxor should be asserted
• 39974dc: 8186548: move jdk.testlibrary.JcmdBase closer to tests
• 50ac138: 8210022: remove jdk.testlibrary.ProcessThread, TestThread and XRun
• 9d3c940: 8218751: Do not store original classfiles inside the CDS archive
• 51b45e7: 8282589: runtime/ErrorHandling/ErrorHandler.java fails on MacOS aarch64 in jdk 11
• 8770332: 8208697: vmTestbase/metaspace/stressHierarchy/stressHierarchy012/TestDescription.java fails with OutOfMemoryError: Metaspace
• 7d16719: 8212151: jdi/ExclusiveBind.java times out due to "bind failed: Address already in use" on Solaris-X64

Your commit was automatically rebased without conflicts.

[openjdk]

@TheRealMDoerr Pushed as commit 5f40afc.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.