8267969: Add vectorized implementation for VectorMask.eq()

[XiaohongGong]

Currently "VectorMask.eq()" is not vectorized:

    public VectorMask<E> eq(VectorMask<E> m) {
        // FIXME: Generate good code here.
        return bOp(m, (i, a, b) -> a == b);
    }

This can be implemented by calling "xor(m.not())" directly.

The performance improved about 1.4x ~ 1.9x for the following benchmark with different basic types:

@Benchmark
public Object eq() {
    boolean[] ma = fm.apply(size);
    boolean[] mb = fmb.apply(size);
    boolean[] mt = fmt.apply(size);
    VectorMask<Byte> m = VectorMask.fromArray(SPECIES, mt, 0);

    for (int ic = 0; ic < INVOC_COUNT; ic++) {
        for (int i = 0; i < ma.length; i += SPECIES.length()) {
            var av = SPECIES.loadMask(ma, i);
            var bv = SPECIES.loadMask(mb, i);

            // accumulate results, so JIT can't eliminate relevant computations
            m = m.and(av.eq(bv));
        }
    }

    return m;
}

---

Progress

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Issue

• JDK-8267969: Add vectorized implementation for VectorMask.eq()

Reviewers

• Paul Sandoz (@PaulSandoz - Reviewer) ⚠️ Review applies to 0e8e0e8
• Nils Eliasson (@neliasso - Reviewer)

Reviewing

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[bridgekeeper]

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[XiaohongGong]

/label hotspot-compiler

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[XiaohongGong]

/label core-libs

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@XiaohongGong
The hotspot-compiler label was successfully added.

[XiaohongGong]

/label hotspot-compiler

[openjdk]

@XiaohongGong
The core-libs label was successfully added.

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[mlbridge]

Webrevs

• 01: Full - Incremental (f3a48026)
• 00: Full (0e8e0e84)

[PaulSandoz]

Looks. Later we may want to consider pushing this down as an intrinsic, perhaps reusing VectorSupport.compare.

[openjdk]

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

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

8267969: Add vectorized implementation for VectorMask.eq()

Reviewed-by: psandoz, neliasso

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At the time when this comment was updated there had been 3 new commits pushed to the master branch:

• 1cea6ca: 8260360: IGV: Short name of combined nodes is hidden by background color
• 7530c00: 8266559: XPathEvaluationResult.XPathResultType.NODESET maps to incorrect type
• b98e52a: 8267570: The comment of the class JavacParser is not appropriate

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[XiaohongGong]

Looks. Later we may want to consider pushing this down as an intrinsic, perhaps reusing VectorSupport.compare.

Thanks for your review @PaulSandoz ! Yes, reusing VectorSupport.compare is an alternative way to do the vectorization.

[XiaohongGong]

/integrate

[openjdk]

@XiaohongGong
Your change (at version f3a4802) is now ready to be sponsored by a Committer.

[neliasso]

Looks good.

[neliasso]

Please wait until you have two reviewers before integrating.

[neliasso]

/sponsor

[openjdk]

@neliasso @XiaohongGong Since your change was applied there have been 3 commits pushed to the master branch:

• 1cea6ca: 8260360: IGV: Short name of combined nodes is hidden by background color
• 7530c00: 8266559: XPathEvaluationResult.XPathResultType.NODESET maps to incorrect type
• b98e52a: 8267570: The comment of the class JavacParser is not appropriate

Your commit was automatically rebased without conflicts.

Pushed as commit 496fb90.

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

[XiaohongGong]

Please wait until you have two reviewers before integrating.

Sure! Thanks so much for looking at this PR!