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  1. 13 Oct, 2020 30 commits
  3. 12 Oct, 2020 10 commits
    • Ng Zhi An's avatar
      [wasm-simd] Guard i64x2 widen i32x4 behind post-mvp flag · 62a16f14
      Ng Zhi An authored 
      These are still not in proposal, so they should be behind the post-mvp
flag.

Bug: v8:10972
Change-Id: I1b53307f334ddd8e21a095c13d7f7abb8ce05203
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2465654
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Reviewed-by: 's avatarBill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70463}
      62a16f14
    • Ng Zhi An's avatar
      [wasm-simd][x64] Don't force dst to be same as src on AVX · 813ae013
      Ng Zhi An authored 
      On AVX, many instructions can have 3 operands, unlike SSE which only has
2. So on SSE we use DefineSameAsFirst on the dst. But on AVX, using that
will cause some unnecessary moves.

This patch changes a couple of F32x4 and S128 instructions to remove
this restriction when AVX is supported.

We can't use AvxHelper since it duplicates the dst for the call to the
AVX instruction, which isn't what we want. The alternative is to
redefine Mulps and other functions here, but there are other callsites
that depend on this duplicated-dst behavior, so it's harder to change.
We can migrate this as we move more logic over to non-DefineSameAsFirst
for AVX.

With the meshopt_decoder.js in the linked bug, it removes 8 SIMD movs
(from a function that has 300+ lines of assembly.)

Note that from agner's microarchitecture.pdf, page 127, "Elimination of
move instructions", many times such moves can be eliminated by the
processor. So this change won't speed up perf, but it helps a bit with
binary size, and decoder pressure.

Bug: v8:10116,v8:9561
Change-Id: I125bfd44e728ef08312620bc00f6433f376e69e3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2465653Reviewed-by: 's avatarBill Budge <bbudge@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70462}
      813ae013
    • Ng Zhi An's avatar
      [wasm-simd][arm64] Prototype i8x16.popcnt · 102b4b3c
      Ng Zhi An authored 
      This implements i8x16.popcnt on arm64 and interpreter.

Bug: v8:11002
Change-Id: Ia94a053d7e0a0c800057ac80865ba6f86ac7caf8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2461058Reviewed-by: 's avatarBill Budge <bbudge@chromium.org>
Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70461}
      102b4b3c
    • v8-ci-autoroll-builder's avatar
      Update V8 DEPS. · 1c6cd2ac
      v8-ci-autoroll-builder authored 
      Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/7e6351e..3110f72

TBR=machenbach@chromium.org,tmrts@chromium.org,v8-waterfall-sheriff@grotations.appspotmail.com

Change-Id: Iee2196a82440a19603db77170b8f224753ab5479
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2466562Reviewed-by: 's avatarv8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Commit-Queue: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#70460}
      1c6cd2ac
    • Ng Zhi An's avatar
      [wasm-simd][x64] Prototype i64x2.bitmask · ceee7cfe
      Ng Zhi An authored 
      Implement on interpreter and x64.

Bug: v8:10997
Change-Id: I3537ce54e1b56cc3b04d91cb07c430c35b88c3aa
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2459109
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Reviewed-by: 's avatarBill Budge <bbudge@chromium.org>
Reviewed-by: 's avatarTobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70459}
      ceee7cfe
    • Zhi An Ng's avatar
      Revert "[csa] Fix semantics of PopAndReturn" · d813f56c
      Zhi An Ng authored 
      This reverts commit 5e5eaf79.

Reason for revert: Failure on V8 Linux gcc https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20gcc/8929?

Original change's description:
> [csa] Fix semantics of PopAndReturn
>
> This CL prohibits using PopAndReturn from the builtins that
> have calling convention with arguments on the stack.
>
> This CL also updates the PopAndReturn tests so that even off-by-one
> errors in the number of poped arguments are caught which was not the
> case before.
>
> Motivation:
>
> PopAndReturn is supposed to be using ONLY in CSA/Torque builtins for
> dropping ALL JS arguments that are currently located on the stack.
> Disallowing PopAndReturn in builtins with stack arguments simplifies
> semantics of this instruction because in case of presence of declared
> stack parameters it's impossible to distinguish the following cases:
> 1) stack parameter is included in JS arguments (and therefore it will
>    be dropped as a part of 'pop' number of arguments),
> 2) stack parameter is NOT included in JS arguments (and therefore it
>    should be dropped in ADDITION to the 'pop' number of arguments).
>
> This issue wasn't noticed before because builtins with stack parameters
> relied on adapter frames machinery to ensure that the expected
> parameters are present on the stack, but on the same time the adapter
> frame tearing down code was effectively recovering the stack pointer
> potentially broken by the CSA builtin.
>
> Once we get rid of the arguments adapter frames keeping stack pointer
> in a valid state becomes crucial.
>
> Bug: v8:5269, v8:10201
> Change-Id: Id3ea9730bb0d41d17999c73136c4dfada374a822
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2460819
> Commit-Queue: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70454}

TBR=tebbi@chromium.org,ishell@chromium.org

Change-Id: I2673982a8f51cbecf421af11b0ce5ad5031fb406
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:5269
Bug: v8:10201
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2465656Reviewed-by: 's avatarZhi An Ng <zhin@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70458}
      d813f56c
    • Ng Zhi An's avatar
      Add --print-wasm-code-function-index · 3d48ae2d
      Ng Zhi An authored 
      This flag allows you to filter printing Wasm code to one particular
function index.

Bug: v8:10791
Change-Id: I400ccaadb8330e5e31e2faefdeddb169cdc85f71
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2459259
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Reviewed-by: 's avatarClemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70457}
      3d48ae2d
    • Ng Zhi An's avatar
      [wasm-simd][x64] Prototype load lane · 673be63e
      Ng Zhi An authored 
      Load lane loads a value from memory and replaces a single lane of a
simd value.

This implements the load (no stores yet) for x64 and interpreter.

Bug: v8:10975
Change-Id: I95d1b5e781ee9adaec23dda749e514f2485eda10
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2444578
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Reviewed-by: 's avatarTobias Tebbi <tebbi@chromium.org>
Reviewed-by: 's avatarBill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70456}
      673be63e
    • Ng Zhi An's avatar
      [wasm-simd] Remove some I64x2 instructions not in proposal · 2c38a477
      Ng Zhi An authored 
      These instructions are not in the proposal, and will be unlikely to be
requested (poor performance, insufficient use cases). As we get more
instruction suggestions, these are sitting around on useful opcodes and
we have to play musical chairs every time we prototype a new
instruction.

Bug: v8:10933
Change-Id: Ic7ce4e514c343d821f76b8c071e41f9bddfbd1ce
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2457669Reviewed-by: 's avatarBill Budge <bbudge@chromium.org>
Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70455}
      2c38a477
    • Igor Sheludko's avatar
      [csa] Fix semantics of PopAndReturn · 5e5eaf79
      Igor Sheludko authored 
      This CL prohibits using PopAndReturn from the builtins that
have calling convention with arguments on the stack.

This CL also updates the PopAndReturn tests so that even off-by-one
errors in the number of poped arguments are caught which was not the
case before.

Motivation:

PopAndReturn is supposed to be using ONLY in CSA/Torque builtins for
dropping ALL JS arguments that are currently located on the stack.
Disallowing PopAndReturn in builtins with stack arguments simplifies
semantics of this instruction because in case of presence of declared
stack parameters it's impossible to distinguish the following cases:
1) stack parameter is included in JS arguments (and therefore it will
   be dropped as a part of 'pop' number of arguments),
2) stack parameter is NOT included in JS arguments (and therefore it
   should be dropped in ADDITION to the 'pop' number of arguments).

This issue wasn't noticed before because builtins with stack parameters
relied on adapter frames machinery to ensure that the expected
parameters are present on the stack, but on the same time the adapter
frame tearing down code was effectively recovering the stack pointer
potentially broken by the CSA builtin.

Once we get rid of the arguments adapter frames keeping stack pointer
in a valid state becomes crucial.

Bug: v8:5269, v8:10201
Change-Id: Id3ea9730bb0d41d17999c73136c4dfada374a822
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2460819
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: 's avatarTobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70454}
      5e5eaf79