8269665: Clean-up toString() methods of some primitive wrappers

[stsypanov]

As of JDK 17 some of primitive wrappers, e.g. Long, Integer, Double and Float in their implementations of Object.toString() delegate to own utility toString(primitive) methods.

Unlike those, Boolean, Byte, Character and Short just duplicate the contents of utility methods in implementations of Object.toString().

Yet another issue is a tiny discrepancy in implementation related to Byte and Short (see the first):

public static String toString(byte b) {
    return Integer.toString((int)b, 10);
}

public String toString() {
    return Integer.toString((int)value);
}

Unlike in overriden method, In utility one they explicitly specify radix which can be skipped, as implementation of Integer.toString(int,int) has a fast-path for radix 10, ending in Integer.toString(int). This simplification gives tiny improvement, see benchmark:

@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@Fork(jvmArgsAppend = {"-Xms2g", "-Xmx2g"})
public class ByteToStringBenchmark {
    @Benchmark
    public String byteToString() {
        return Byte.toString((byte) 1);
    }
}

Results:

before

Benchmark                                                            Mode  Cnt     Score     Error   Units
ByteToStringBenchmark.byteToString                                   avgt   30    11,648 ±   1,906   ns/op
ByteToStringBenchmark.byteToString:·gc.alloc.rate                    avgt   30  3288,576 ± 418,119  MB/sec
ByteToStringBenchmark.byteToString:·gc.alloc.rate.norm               avgt   30    48,001 ±   0,001    B/op
ByteToStringBenchmark.byteToString:·gc.churn.G1_Eden_Space           avgt   30  3301,804 ± 455,932  MB/sec
ByteToStringBenchmark.byteToString:·gc.churn.G1_Eden_Space.norm      avgt   30    48,158 ±   2,085    B/op
ByteToStringBenchmark.byteToString:·gc.churn.G1_Survivor_Space       avgt   30     0,004 ±   0,001  MB/sec
ByteToStringBenchmark.byteToString:·gc.churn.G1_Survivor_Space.norm  avgt   30    ≈ 10⁻⁴              B/op
ByteToStringBenchmark.byteToString:·gc.count                         avgt   30   202,000            counts
ByteToStringBenchmark.byteToString:·gc.time                          avgt   30   413,000                ms

after

Benchmark                                                            Mode  Cnt     Score     Error   Units
ByteToStringBenchmark.byteToString                                   avgt   30    10,016 ±   0,530   ns/op
ByteToStringBenchmark.byteToString:·gc.alloc.rate                    avgt   30  3673,700 ± 167,450  MB/sec
ByteToStringBenchmark.byteToString:·gc.alloc.rate.norm               avgt   30    48,001 ±   0,001    B/op
ByteToStringBenchmark.byteToString:·gc.churn.G1_Eden_Space           avgt   30  3662,406 ± 205,978  MB/sec
ByteToStringBenchmark.byteToString:·gc.churn.G1_Eden_Space.norm      avgt   30    47,870 ±   1,750    B/op
ByteToStringBenchmark.byteToString:·gc.churn.G1_Survivor_Space       avgt   30     0,004 ±   0,002  MB/sec
ByteToStringBenchmark.byteToString:·gc.churn.G1_Survivor_Space.norm  avgt   30    ≈ 10⁻⁴              B/op
ByteToStringBenchmark.byteToString:·gc.count                         avgt   30   224,000            counts
ByteToStringBenchmark.byteToString:·gc.time                          avgt   30   358,000                ms

---

Progress

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

Issue

• JDK-8269665: Clean-up toString() methods of some primitive wrappers

Reviewers

• Claes Redestad (@cl4es - Reviewer)

Reviewing

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$ git checkout pull/4633

Update a local copy of the PR:
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$ git pull https://git.openjdk.java.net/jdk pull/4633/head

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https://git.openjdk.java.net/jdk/pull/4633.diff

[bridgekeeper]

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[openjdk]

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[mlbridge]

Webrevs

• 02: Full - Incremental (b9fb156c)
• 01: Full - Incremental (e939d72b)
• 00: Full (7a5fe65c)

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[stsypanov]

@stsypanov This pull request has been inactive for more than 4 weeks and will be automatically closed if another 4 weeks passes without any activity. To avoid this, simply add a new comment to the pull request. Feel free to ask for assistance if you need help with progressing this pull request towards integration!

Not now

[cl4es]

This change makes sense given the evidence that the radix tests in Integer.toString(int, int) are not elided. Same for the equivalent change in Short.java.

[openjdk]

⚠️ @stsypanov the full name on your profile does not match the author name in this pull requests' HEAD commit. If this pull request gets integrated then the author name from this pull requests' HEAD commit will be used for the resulting commit. If you wish to push a new commit with a different author name, then please run the following commands in a local repository of your personal fork:

$ git checkout 8269665
$ git commit -c user.name='Preferred Full Name' --allow-empty -m 'Update full name'
$ git push

[openjdk]

@stsypanov 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:

8269665: Clean-up toString() methods of some primitive wrappers

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 405 new commits pushed to the master branch:

• 7cc1eb3: Merge
• e351de3: 8271272: C2: assert(!had_error) failed: bad dominance
• 6180cf1: 8271512: ProblemList serviceability/sa/sadebugd/DebugdConnectTest.java due to 8270326
• a1b5b81: 8271507: ProblemList SA tests that are failing with ZGC due to JDK-8248912
• 4bc9b04: 8263059: security/infra/java/security/cert/CertPathValidator/certification/ComodoCA.java fails due to revoked cert
• d6bb846: 8248899: security/infra/java/security/cert/CertPathValidator/certification/QuoVadisCA.java fails, Certificate has been revoked
• 71ca0c0: 8270848: Redundant unsafe opmask register allocation in some instruction patterns.
• 6c68ce2: 8270947: AArch64: C1: use zero_words to initialize all objects
• cd7e30e: 8271242: Add Arena regression tests
• 5b3c418: 8270321: Startup regressions in 18-b5 caused by JDK-8266310
• ... and 395 more: https://git.openjdk.java.net/jdk/compare/ee0247f056daea7a0afdd572d13fb30f5164e889...master

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.

As you do not have Committer status in this project an existing Committer must agree to sponsor your change. Possible candidates are the reviewers of this PR (@cl4es) but any other Committer may sponsor as well.

➡️ To flag this PR as ready for integration with the above commit message, type /integrate in a new comment. (Afterwards, your sponsor types /sponsor in a new comment to perform the integration).

[stsypanov]

/integrate

[openjdk]

@stsypanov
Your change (at version b9fb156) is now ready to be sponsored by a Committer.

[cl4es]

/sponsor

[openjdk]

Going to push as commit 72145f3.
Since your change was applied there have been 405 commits pushed to the master branch:

• 7cc1eb3: Merge
• e351de3: 8271272: C2: assert(!had_error) failed: bad dominance
• 6180cf1: 8271512: ProblemList serviceability/sa/sadebugd/DebugdConnectTest.java due to 8270326
• a1b5b81: 8271507: ProblemList SA tests that are failing with ZGC due to JDK-8248912
• 4bc9b04: 8263059: security/infra/java/security/cert/CertPathValidator/certification/ComodoCA.java fails due to revoked cert
• d6bb846: 8248899: security/infra/java/security/cert/CertPathValidator/certification/QuoVadisCA.java fails, Certificate has been revoked
• 71ca0c0: 8270848: Redundant unsafe opmask register allocation in some instruction patterns.
• 6c68ce2: 8270947: AArch64: C1: use zero_words to initialize all objects
• cd7e30e: 8271242: Add Arena regression tests
• 5b3c418: 8270321: Startup regressions in 18-b5 caused by JDK-8266310
• ... and 395 more: https://git.openjdk.java.net/jdk/compare/ee0247f056daea7a0afdd572d13fb30f5164e889...master

Your commit was automatically rebased without conflicts.

[openjdk]

@cl4es @stsypanov Pushed as commit 72145f3.

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