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RFR: 8264352: AArch64: Optimize vector "not/andNot" for NEON and SVE

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Xiaohong Gong

RFR: 8264352: AArch64: Optimize vector "not/andNot" for NEON and SVE

Since the vector bitwise `"andNot"` is implemented with `"v1.and(v2.xor(-1))"`, the generated codes with SVE look like:
mov z16.b, #-1
eor z17.d, z20.d, z16.d
and z18.d, z18.d, z17.d
This could be improved with a single instruction:
bic z16.d, z16.d, z18.d
Similarly, the following optimization for NEON is also needed:
not v21.16b, v21.16b
and v21.16b, v21.16b, v18.16b ==> bic v21.16b, v18.16b, v21.16b
This patch also adds the following optimization to vector` "not"` for SVE which has already been added for NEON:
mov z16.b, #-1
eor z17.d, z20.d, z16.d ==> not z17.d, p7/m, z20.d
The performance can improve about `16% ~ 36%` with NEON for the `"AND_NOT"` benchmark [1].

[1] https://github.com/openjdk/panama-vector/blob/vectorIntrinsics/test/jdk/jdk/incubator/vector/benchmark/src/main/java/benchmark/jdk/incubator/vector/ByteMaxVector.java#L343

Tested tier1 and jdk:tier3.

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Commit messages:
- 8264352: AArch64: Optimize vector "not/andNot" for NEON and SVE

Changes: https://git.openjdk.java.net/jdk/pull/3370/files
Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3370&range=00
Issue: https://bugs.openjdk.java.net/browse/JDK-8264352
Stats: 219 lines in 7 files changed: 185 ins; 0 del; 34 mod
Patch: https://git.openjdk.java.net/jdk/pull/3370.diff
Fetch: git fetch https://git.openjdk.java.net/jdk pull/3370/head:pull/3370

PR: https://git.openjdk.java.net/jdk/pull/3370

Andrew Haley-2

Re: RFR: 8264352: AArch64: Optimize vector "not/andNot" for NEON and SVE

On Wed, 7 Apr 2021 05:53:46 GMT, Xiaohong Gong <[hidden email]> wrote:

> Since the vector bitwise `"andNot"` is implemented with `"v1.and(v2.xor(-1))"`, the generated codes with SVE look like:
> mov z16.b, #-1
> eor z17.d, z20.d, z16.d
> and z18.d, z18.d, z17.d
> This could be improved with a single instruction:
> bic z16.d, z16.d, z18.d
> Similarly, the following optimization for NEON is also needed:
> not v21.16b, v21.16b
> and v21.16b, v21.16b, v18.16b ==> bic v21.16b, v18.16b, v21.16b
> This patch also adds the following optimization to vector` "not"` for SVE which has already been added for NEON:
> mov z16.b, #-1
> eor z17.d, z20.d, z16.d ==> not z17.d, p7/m, z20.d
> The performance can improve about `16% ~ 36%` with NEON for the `"AND_NOT"` benchmark [1].
>
> [1] https://github.com/openjdk/panama-vector/blob/vectorIntrinsics/test/jdk/jdk/incubator/vector/benchmark/src/main/java/benchmark/jdk/incubator/vector/ByteMaxVector.java#L343
>
> Tested tier1 and jdk:tier3.

Looks OK. Is there any test code for this is mainline?

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PR: https://git.openjdk.java.net/jdk/pull/3370

Xiaohong Gong

Re: RFR: 8264352: AArch64: Optimize vector "not/andNot" for NEON and SVE

On Wed, 7 Apr 2021 08:31:19 GMT, Andrew Haley <[hidden email]> wrote:

> Looks OK. Is there any test code for this is mainline?

Hi @theRealAph , thanks for looking at this PR. Yes, there is the Vector API jtreg tests that have covered the opcode `NOT/AND_NOT`.
Please see the tests for byte vector: https://github.com/openjdk/jdk/blob/master/test/jdk/jdk/incubator/vector/ByteMaxVectorTests.java#L1708
and https://github.com/openjdk/jdk/blob/master/test/jdk/jdk/incubator/vector/ByteMaxVectorTests.java#L4602

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PR: https://git.openjdk.java.net/jdk/pull/3370

Andrew Haley-2

Re: RFR: 8264352: AArch64: Optimize vector "not/andNot" for NEON and SVE

In reply to this post by Xiaohong Gong

On Wed, 7 Apr 2021 05:53:46 GMT, Xiaohong Gong <[hidden email]> wrote:

Marked as reviewed by aph (Reviewer).

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PR: https://git.openjdk.java.net/jdk/pull/3370

Ningsheng Jian-2

Re: RFR: 8264352: AArch64: Optimize vector "not/andNot" for NEON and SVE

In reply to this post by Xiaohong Gong

On Wed, 7 Apr 2021 05:53:46 GMT, Xiaohong Gong <[hidden email]> wrote:

Looks good.

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Marked as reviewed by njian (Committer).

PR: https://git.openjdk.java.net/jdk/pull/3370

Xiaohong Gong

Re: RFR: 8264352: AArch64: Optimize vector "not/andNot" for NEON and SVE

In reply to this post by Andrew Haley-2

On Wed, 7 Apr 2021 09:03:55 GMT, Andrew Haley <[hidden email]> wrote:

>> Since the vector bitwise `"andNot"` is implemented with `"v1.and(v2.xor(-1))"`, the generated codes with SVE look like:
>> mov z16.b, #-1
>> eor z17.d, z20.d, z16.d
>> and z18.d, z18.d, z17.d
>> This could be improved with a single instruction:
>> bic z16.d, z16.d, z18.d
>> Similarly, the following optimization for NEON is also needed:
>> not v21.16b, v21.16b
>> and v21.16b, v21.16b, v18.16b ==> bic v21.16b, v18.16b, v21.16b
>> This patch also adds the following optimization to vector` "not"` for SVE which has already been added for NEON:
>> mov z16.b, #-1
>> eor z17.d, z20.d, z16.d ==> not z17.d, p7/m, z20.d
>> The performance can improve about `16% ~ 36%` with NEON for the `"AND_NOT"` benchmark [1].
>>
>> [1] https://github.com/openjdk/panama-vector/blob/vectorIntrinsics/test/jdk/jdk/incubator/vector/benchmark/src/main/java/benchmark/jdk/incubator/vector/ByteMaxVector.java#L343
>>
>> Tested tier1 and jdk:tier3.
>
> Marked as reviewed by aph (Reviewer).

Thanks for the review @theRealAph @nsjian !

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PR: https://git.openjdk.java.net/jdk/pull/3370

Xiaohong Gong

Integrated: 8264352: AArch64: Optimize vector "not/andNot" for NEON and SVE

In reply to this post by Xiaohong Gong

On Wed, 7 Apr 2021 05:53:46 GMT, Xiaohong Gong <[hidden email]> wrote:

This pull request has now been integrated.

Changeset: e89542fb
Author: Xiaohong Gong <[hidden email]>
Committer: Ningsheng Jian <[hidden email]>
URL: https://git.openjdk.java.net/jdk/commit/e89542fb
Stats: 219 lines in 7 files changed: 185 ins; 0 del; 34 mod

8264352: AArch64: Optimize vector "not/andNot" for NEON and SVE

Reviewed-by: aph, njian

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PR: https://git.openjdk.java.net/jdk/pull/3370