8229845: Decrease memory consumption of BigInteger.toString()

[bplb]

Please review this proposed fix. The review was initially in this thread

http://mail.openjdk.java.net/pipermail/core-libs-dev/2019-August/061914.html

under the old Hg SCM. The changes proposed here are derived from the final (.05) patch in the previous review which was posted in

http://mail.openjdk.java.net/pipermail/core-libs-dev/2019-August/062012.html.

---

Progress

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

Testing

	Linux x32	Linux x64	Windows x64	macOS x64
Build	✔️ (1/1 passed)	✔️ (5/5 passed)	✔️ (2/2 passed)	✔️ (2/2 passed)
Test (tier1)		✔️ (9/9 passed)	❌ (1/9 failed)	✔️ (9/9 passed)

Failed test task

• Windows x64 (hs/tier1 compiler)

Issue

• JDK-8229845: Decrease memory consumption of BigInteger.toString()

Reviewers

• Claes Redestad (@cl4es - Reviewer)

Download

$ git fetch https://git.openjdk.java.net/jdk pull/819/head:pull/819
$ git checkout pull/819

[bridgekeeper]

👋 Welcome back bpb! 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]

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[mlbridge]

Webrevs

• 00: Full (b4106d0)

[cl4es]

LGTM.

A microbenchmark or something that summarizes the improvement and can verify that we don't regress on some variant would've been nice.

[openjdk]

@bplb 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:

8229845: Decrease memory consumption of BigInteger.toString()

Reviewed-by: redestad

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 10 new commits pushed to the master branch:

• 107fb9c: 8255049: Remove support for the hsdis decode_instructions entry point in hotspot
• c1524c5: 8255208: CodeStrings passed to Disassembler::decode are ignored
• 8e5dff0: 8255213: Shenandoah build fails without JFR after JDK-8255036
• fe74f3c: 8255224: x86_32 tests fail with "bad AD file" after JDK-8223051
• 64dc4b1: 8255225: compiler/aot tests fail on Windows with NPE during artifact resolution
• a824781: 8255210: [Vector API] jdk/incubator/vector/Int256VectorTests.java crashes on AVX512 machines
• 2ca7a08: 8255268: 32-bit failures in runtime/Metaspace/elastic
• d8d9197: 8242559: Clean the "libawt_xawt" library from code for headless mode
• ff5f226: 8255086: Update the root locale display names
• 8afdcae: 8255031: Update java/util/prefs/AddNodeChangeListener.java to report more failure info

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.

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[cl4es]

What's the hold-up on this?

[bplb]

/integrate

[openjdk]

@bplb Since your change was applied there have been 456 commits pushed to the master branch:

• ff00c59: 8256569: Add C2 compiler stress flags to CTW
• e7c7469: 8246378: [Windows] assert on MethodHandle logging code
• 98a5d5a: 8256664: Shenandoah: Cleanup after JDK-8212879
• b99fd4c: 8033441: print line numbers with -XX:+PrintOptoAssembly
• 266dea0: 8256688: Shenandoah: Lock rank inversion after JDK-8212879
• aeba925: 8256416: ZGC: Lower ZMarkCompleteTimeout
• 10ba541: 8256727: ZGC: Clean out dead code after JDK-8212879
• eb35ade: 6232281: -XX:-UseLoopSafepoints causes assert(v_false,"Parse::remove_useless_nodes missed this node")
• a25fb03: 8256406: G1 x86 C1/Interpreter post write barrier always uses 32 bit to access variable sized PtrQueue::_index
• f576628: 8256633: Fix product build on Windows+Arm64
• ... and 446 more: https://git.openjdk.java.net/jdk/compare/0aa3c92577687e02f941260dc0f176f9dcd4ae59...master

Your commit was automatically rebased without conflicts.

Pushed as commit 2ae3e51.

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