8293409: [vectorapi] Intrinsify VectorSupport.indexVector

[XiaohongGong]

"VectorSupport.indexVector()" is used to compute a vector that contains the index values based on a given vector and a scale value (i.e. index = vec + iota * scale). This function is widely used in other APIs like "VectorMask.indexInRange" which is useful to the tail loop vectorization. And it can be easily implemented with the vector instructions.

This patch adds the vector intrinsic implementation of it. The steps are:

1. Load the const "iota" vector.

We extend the "vector_iota_indices" stubs from byte to other integral types. For floating point vectors, it needs an additional vector cast to get the right iota values.

2. Compute indexes with "vec + iota * scale"

Here is the performance result to the new added micro benchmark on ARM NEON:

Benchmark                              Gain
IndexVectorBenchmark.byteIndexVector   1.477
IndexVectorBenchmark.doubleIndexVector 5.031
IndexVectorBenchmark.floatIndexVector  5.342
IndexVectorBenchmark.intIndexVector    5.529
IndexVectorBenchmark.longIndexVector   3.177
IndexVectorBenchmark.shortIndexVector  5.841

Please help to review and share the feedback! Thanks in advance!

---

Progress

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Issue

• JDK-8293409: [vectorapi] Intrinsify VectorSupport.indexVector

Reviewers

• Eric Liu (@theRealELiu - Committer)

Reviewing

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[bridgekeeper[bot]]

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[openjdk[bot]]

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[XiaohongGong]

/label add hotspot-compiler

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@XiaohongGong The hotspot-compiler label was successfully added.

[mlbridge[bot]]

Webrevs

• 01: Full - Incremental (53f042d3)
• 00: Full (2ad157b6)

[XiaohongGong]

Hi, could anyone please help to take a look at this PR? Thanks in advance for your time!

[vnkozlov]

@jatin-bhateja and @sviswa7 please look on this enhancement as Vector API experts.

[XiaohongGong]

Ping again, could anyone please help to take a review at this PR? Thanks in advance!

[XiaohongGong]

Hi @jatin-bhateja , all your comments have been addressed. Please help to look at the changes again! Thanks in advance!

[openjdk[bot]]

@XiaohongGong 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:

8293409: [vectorapi] Intrinsify VectorSupport.indexVector

Reviewed-by: eliu, jbhateja

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 55 new commits pushed to the master branch:

• f502ab85c987be827d36b0a29f77ec5ce5bb3d01: 8295435: Build failure with GCC7 after JDK-8294314 due to strict-overflow warnings
• 3f4964f83d6f03efbee2fb34aa8258d4fc923efb: 8293291: Simplify relocation of native pointers in archive heap
• 1553551d821d92e529116e6ce56846831b13f492: 8286918: Better HttpServer service
• 400aa2fb2c00c783f08b8e8dfc0ef9e63cbc4607: 8286511: Improve macro allocation
• 2cee77444feb7911dc2234cbde0dccee4e6279c9: 8289366: Improve HTTP/2 client usage
• 1ae683652134782745c4a7f261af3cbfc241e683: 8288508: Enhance ECDSA usage
• 40539de8da78294a6d0ff0236687817cd767754b: 8286910: Improve JNDI lookups
• 896a29dfaef6f0fb8e90b85205b599923d6e9e53: 8287446: Enhance icon presentations
• 5a8e5ea3e234dc50935c09519791a59ee84f08c0: 8286526: Improve NTLM support
• c622d56a0da5c27490bbe8ec572865b934499833: 8286519: Better memory handling
• ... and 45 more: https://git.openjdk.org/jdk/compare/d3781ac8a38943d8a20304e770b01d5418ee33d0...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.

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

[XiaohongGong]

Thanks for the review @jatin-bhateja @theRealELiu !

[XiaohongGong]

/integrate

[openjdk[bot]]

Going to push as commit 857b0f9b05bc711f3282a0da85fcff131fffab91. Since your change was applied there have been 56 commits pushed to the master branch:

• 3f3d63d02ada66d5739e690d786684d25dc59004: 8294211: Zero: Decode arch-specific error context if possible
• f502ab85c987be827d36b0a29f77ec5ce5bb3d01: 8295435: Build failure with GCC7 after JDK-8294314 due to strict-overflow warnings
• 3f4964f83d6f03efbee2fb34aa8258d4fc923efb: 8293291: Simplify relocation of native pointers in archive heap
• 1553551d821d92e529116e6ce56846831b13f492: 8286918: Better HttpServer service
• 400aa2fb2c00c783f08b8e8dfc0ef9e63cbc4607: 8286511: Improve macro allocation
• 2cee77444feb7911dc2234cbde0dccee4e6279c9: 8289366: Improve HTTP/2 client usage
• 1ae683652134782745c4a7f261af3cbfc241e683: 8288508: Enhance ECDSA usage
• 40539de8da78294a6d0ff0236687817cd767754b: 8286910: Improve JNDI lookups
• 896a29dfaef6f0fb8e90b85205b599923d6e9e53: 8287446: Enhance icon presentations
• 5a8e5ea3e234dc50935c09519791a59ee84f08c0: 8286526: Improve NTLM support
• ... and 46 more: https://git.openjdk.org/jdk/compare/d3781ac8a38943d8a20304e770b01d5418ee33d0...master

Your commit was automatically rebased without conflicts.

[openjdk[bot]]

@XiaohongGong Pushed as commit 857b0f9b05bc711f3282a0da85fcff131fffab91.

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