8350663: AArch64: Enable UseSignumIntrinsic by default

[cnqpzhang]

According to tests on Arm CPUs Neoverse-N1/N2/V1/V2 and Ampere-Altra/AmpereOne, -XX:+UseSignumIntrinsic can provide consistent positive performance boost on singnum microbenchmarks (1-4,5,7 in below list) and no obvious regression (ops/s change <0.1%) on other relevant tests (6,9-12). In addition, "Apple M1 shows no regression with signum intrinsics" (verified by @theRealAph). So, it can be the time to enable this UseSignumIntrinsic flag by default for aarch64-port. By the way, x86 and riscv ports have already configured it on by default.

Tests: passed JTReg tier1 tests on Ampere-1A, no regression found, and particularly checked test results of two signum cases (13,14), both are in good state.

1. org.openjdk.bench.java.lang.MathBench.signumDouble
2. org.openjdk.bench.java.lang.MathBench.signumFloat
3. org.openjdk.bench.java.lang.StrictMathBench.sigNumDouble
4. org.openjdk.bench.java.lang.StrictMathBench.signumFloat
5. org.openjdk.bench.vm.compiler.Signum._1_signumFloatTest
6. org.openjdk.bench.vm.compiler.Signum._2_overheadFloat
7. org.openjdk.bench.vm.compiler.Signum._3_signumDoubleTest
8. org.openjdk.bench.vm.compiler.Signum._4_overheadDouble
9. org.openjdk.bench.vm.compiler.Signum._5_copySignFloatTest
10. org.openjdk.bench.vm.compiler.Signum._6_overheadCopySignFloat
11. org.openjdk.bench.vm.compiler.Signum._7_copySignDoubleTest
12. org.openjdk.bench.vm.compiler.Signum._8_overheadCopySignDouble
13. JTReg: compiler/vectorization/TestSignumVector.java
14. JTReg: compiler/intrinsics/math/TestSignumIntrinsic.java

---

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Issue

• JDK-8350663: AArch64: Enable UseSignumIntrinsic by default (Enhancement - P4)

Reviewers

• Andrew Dinn (@adinn - Reviewer)

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[openjdk]

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

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

8350663: AArch64: Enable UseSignumIntrinsic by default

Reviewed-by: adinn

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At the time when this comment was updated there had been 177 new commits pushed to the master branch:

• a37d843: 8352015: LIBVERIFY_OPTIMIZATION remove special optimization settings
• b891bfa: 8352022: RISC-V: Support Zfa fminm_h/fmaxm_h for float16
• 20f1bca: 8351187: Add JFR monitor notification event
• 46b3d1d: 8351382: New test containers/docker/TestMemoryWithSubgroups.java is failing
• 558c015: 8351921: G1: Pinned regions with pinned objects only reachable by native code crash VM
• f8c2122: 8352138: G1: Remove G1AddMetaspaceDependency.java test
• e1bcff3: 8345687: Improve the implementation of SegmentFactories::allocateSegment
• f4ddac5: 8331201: UBSAN enabled build reports on Linux x86_64 runtime error: shift exponent 65 is too large for 64-bit type 'long unsigned int'
• 38499b3: 8352084: Add more test code in TestSetupAOT.java
• 19154f7: 8351970: Retire JavaLangAccess::exit
• ... and 167 more: https://git.openjdk.org/jdk/compare/1f10ffba88119caab169b1fc43ccfd143e3b85a6...master

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[mlbridge]

Webrevs

• 00: Full (2e012df3)

[cnqpzhang]

Hi @theRealAph Could you please help review this? Thanks.

[adinn]

The change is good.

[cnqpzhang]

/integrate

[openjdk]

@cnqpzhang
Your change (at version 2e012df) is now ready to be sponsored by a Committer.

[adinn]

/sponsor

[openjdk]

Going to push as commit b025d8c.
Since your change was applied there have been 177 commits pushed to the master branch:

• a37d843: 8352015: LIBVERIFY_OPTIMIZATION remove special optimization settings
• b891bfa: 8352022: RISC-V: Support Zfa fminm_h/fmaxm_h for float16
• 20f1bca: 8351187: Add JFR monitor notification event
• 46b3d1d: 8351382: New test containers/docker/TestMemoryWithSubgroups.java is failing
• 558c015: 8351921: G1: Pinned regions with pinned objects only reachable by native code crash VM
• f8c2122: 8352138: G1: Remove G1AddMetaspaceDependency.java test
• e1bcff3: 8345687: Improve the implementation of SegmentFactories::allocateSegment
• f4ddac5: 8331201: UBSAN enabled build reports on Linux x86_64 runtime error: shift exponent 65 is too large for 64-bit type 'long unsigned int'
• 38499b3: 8352084: Add more test code in TestSetupAOT.java
• 19154f7: 8351970: Retire JavaLangAccess::exit
• ... and 167 more: https://git.openjdk.org/jdk/compare/1f10ffba88119caab169b1fc43ccfd143e3b85a6...master

Your commit was automatically rebased without conflicts.

[openjdk]

@adinn @cnqpzhang Pushed as commit b025d8c.

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