[arm64][wasm] Add 8x8 Deinterleave using UZP [v8/v8 : main]

[Matthias Liedtke (Gerrit)]

Attention needed from Emily Boarer

Matthias Liedtke voted and added 1 comment

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Code-Review

+1

1 comment

Patchset-level comments

File-level comment, Patchset 1 (Latest):

Matthias Liedtke . unresolved

LGTM.
This is guarded behind the `--experimental-wasm-simd-opt`, correct?

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[Sam Parker-Haynes (Gerrit)]

Attention needed from Emily Boarer

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Patchset-level comments

File-level comment, Patchset 1 (Latest):

Matthias Liedtke . unresolved

LGTM.
This is guarded behind the `--experimental-wasm-simd-opt`, correct?

Sam Parker-Haynes

Hi Matthias, indeed it is. Emily will have another patch in this area and then, I hope, we'll be happy, performance-wise, with enabling the pass (but without the deinterleaving load support)

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Gerrit-Change-Number: 7165874

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[Matthias Liedtke (Gerrit)]

Attention needed from Emily Boarer

Matthias Liedtke added 1 comment

Patchset-level comments

File-level comment, Patchset 1 (Latest):

Matthias Liedtke . unresolved

LGTM.
This is guarded behind the `--experimental-wasm-simd-opt`, correct?

Sam Parker-Haynes

Hi Matthias, indeed it is. Emily will have another patch in this area and then, I hope, we'll be happy, performance-wise, with enabling the pass (but without the deinterleaving load support)

Matthias Liedtke

We'd probably need a fuzzing story here before shipping.
Right now I guess the chance is low that a fuzzer emits instructions with the "exactly" correct lane configurations to trigger these optimizations, but let's start with enabling these flags on the fuzzers?

https://chromium-review.googlesource.com/c/v8/v8/+/7169185

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Gerrit-Owner: Emily Boarer <emily....@arm.com>

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[Matthias Liedtke (Gerrit)]

Attention needed from Emily Boarer and Sam Parker-Haynes

Matthias Liedtke added 1 comment

Patchset-level comments

File-level comment, Patchset 1 (Latest):

Matthias Liedtke . resolved

LGTM.
This is guarded behind the `--experimental-wasm-simd-opt`, correct?

Sam Parker-Haynes

Hi Matthias, indeed it is. Emily will have another patch in this area and then, I hope, we'll be happy, performance-wise, with enabling the pass (but without the deinterleaving load support)

Matthias Liedtke

We'd probably need a fuzzing story here before shipping.
Right now I guess the chance is low that a fuzzer emits instructions with the "exactly" correct lane configurations to trigger these optimizations, but let's start with enabling these flags on the fuzzers?

https://chromium-review.googlesource.com/c/v8/v8/+/7169185

Matthias Liedtke

Resolving this comment as it's unrelated to the change itself and therefore shouldn't block it from landing.

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[Sam Parker-Haynes (Gerrit)]

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Sam Parker-Haynes voted Code-Review+1

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+1

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[Sam Parker-Haynes (Gerrit)]

Attention needed from Emily Boarer

Sam Parker-Haynes voted Commit-Queue+2

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+2

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[V8 LUCI CQ (Gerrit)]

V8 LUCI CQ submitted the change

Change information

Commit message:

[arm64][wasm] Add 8x8 Deinterleave using UZP

Two UZP/UZP2 instructions can be chained to extract every fourth element
in a shuffle, from a different offset for each combination.

Change-Id: Ifd8960d7df935a09f435cb6bd431717586c6ecb3

Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/7165874

Reviewed-by: Matthias Liedtke <mlie...@chromium.org>

Reviewed-by: Sam Parker-Haynes <sam.p...@arm.com>

Commit-Queue: Sam Parker-Haynes <sam.p...@arm.com>

Cr-Commit-Position: refs/heads/main@{#103803}

Files:

• M src/compiler/backend/arm64/instruction-selector-arm64.cc
• M src/wasm/simd-shuffle.cc
• M src/wasm/simd-shuffle.h
• M test/mjsunit/wasm/half-shuffles.js
• M test/unittests/compiler/arm64/turboshaft-instruction-selector-arm64-unittest.cc

Change size: M

Delta: 5 files changed, 125 insertions(+), 3 deletions(-)

Branch: refs/heads/main

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Gerrit-Change-Id: Ifd8960d7df935a09f435cb6bd431717586c6ecb3

Gerrit-Change-Number: 7165874

Gerrit-PatchSet: 2

Gerrit-Owner: Emily Boarer <emily....@arm.com>

Gerrit-Reviewer: Matthias Liedtke <mlie...@chromium.org>

Gerrit-Reviewer: Sam Parker-Haynes <sam.p...@arm.com>

Gerrit-Reviewer: V8 LUCI CQ <v8-s...@luci-project-accounts.iam.gserviceaccount.com>