Bug: v8:7777
Change-Id: I0227ee37018e718014b8a8fbdba93e82a2209ae0
Reviewed-on: https://chromium-review.googlesource.com/c/1480372Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59761}

- Remove unused IsSpecialization
- Simplify IsCompatibleForLoad

Change-Id: I555adf9869322b600072c5006ff71f6b846d4241
Reviewed-on: https://chromium-review.googlesource.com/c/1479958Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59760}

This change adds two spilling modes: SpillAtDefinition and SpillDeferred.
The former is the known spilling mode where we spill at definition. The
latter spills only in deferred code regions. This is implemented based on
control flow aware allocation and its invariants.

The effect is mostly the same as splintering with the exception of
forward looking allocation decisions still being impacted by register
constraints in deferred code.

Change-Id: Ia708e5765dd095196a8127deb2d8bec950d37e04
Reviewed-on: https://chromium-review.googlesource.com/c/1437118Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Stephan Herhut <herhut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59759}

This merges the "do-nothing" case with the "done" case as the former
is no longer useful. This also fixes a bug where the idle time handler
would not make progress by always returning "do-nothing".

Change-Id: Ibdd3189e4fd35acc5405aa82a13ea8ee2fd74cc6
Reviewed-on: https://chromium-review.googlesource.com/c/1478695
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59758}

This is a reland of 49de5875

Original change's description:
> [heap] Perform more embedder tracing in incremental marking step
> 
> This should fix GC latency regressions introduced in 4c6598.
> 
> Bug: chromium:926189, chromium:930844, chromium:930693,chromium:931629
> Change-Id: I81c91829badbeea82d6e44670d07794632869424
> Reviewed-on: https://chromium-review.googlesource.com/c/1477216
> Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#59668}

Bug: chromium:926189, chromium:930844, chromium:930693, chromium:931629
Change-Id: Ifa77647668bb052bb102b643182baf406cb9e059
Reviewed-on: https://chromium-review.googlesource.com/c/1477279Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59757}

Change-Id: Ib45690bb03b9c76502afed89a71e1dc9a545893b
Reviewed-on: https://chromium-review.googlesource.com/c/1481213
Commit-Queue: Sven Sauleau <ssauleau@igalia.com>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59756}

This cl moves the valid feeback vector checks to the builtins and uses
fast paths runtime when possible even whithout a valid feedback vector.
For LoadNamedProperty it calls LoadIC_Uninitialized which does not need
any type feedback and for LoadKeyedProperty it follows the megamorphic path
but doesnot use the stub cache.

Bug: v8:8293
Change-Id: I6ef9653e3f43c15cb882cbf82c3c2f63fb705a81
Reviewed-on: https://chromium-review.googlesource.com/c/1475393Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59755}

TBR=santa

Change-Id: I0ff05d47526d7e648c026daecb63ad80b668d9d8
Reviewed-on: https://chromium-review.googlesource.com/c/1481215Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59754}

The DCHECK verified capacity just before the call to EnsureCapacity()
(which extends capacity if needed). This DCHECK can just be removed
since FixedArray::set() already checks the given index is in-bounds.

Drive-by: Remove similar duplicate DCHECKs in FixedArrayBuilder.

Bug: chromium:933776
Change-Id: I9f058548063a170ea6dce112a3877792887efcca
Reviewed-on: https://chromium-review.googlesource.com/c/1479955Reviewed-by: Simon Zünd <szuend@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59753}

The default TracingController (used by d8 and Node) has some concurrency
issues. The new test flushes these out, when a second thread logs trace
events while the main thread calls StopTracing().

- Use an acquire load in UpdateCategoryGroupEnabledFlags() because this
  was racing with GetCategoryGroupEnabled() where a new category is
  added in the slow path. g_category_groups is append-only, but
  reads/writes to g_category_index need to be correctly ordered so that
  new categories are added and only then is the change to the index
  visible. The relaxed load ignored this and caused unsynchronized
  read/write.
- Use a relaxed load in ~ScopedTracer() to access category_group_enabled
  as this previously used a non-atomic operation which caused a race
  with UpdateCategoryGroupEnabledFlag() which does a relaxed store.
- Replace TracingController::mode_ with an atomic bool as read/writes to
  mode_ were not synchronized and caused TSAN errors. It only has two
  states and it doesn't seem like we will extend this so just convert it
  to bool.
- Take the lock around calling trace_object->Initialize in
  AddTraceEvent(), and around trace_buffer_->Flush() in StopTracing().
  These two raced previously as the underlying TraceBufferRingBuffer
  passes out pointers to TraceObjects in a synchronized way, but the
  caller (AddTraceEvent) then writes into the object without
  synchronization. This leads to races when Flush() is called, at which
  time TraceBufferRingBuffer assumes that all the pointers it handed out
  are to valid, initialized TraceObjects - which is not true because
  AddTraceEvent may still be calling Initialize on them. This could be
  the cause of issues in Node.js where the last line of tracing/logging
  sometimes gets cut off. This is kind of a band-aid solution - access
  to the TraceObjects handed out by the ring buffer really needs proper
  synchronization which at this point would require redesign. It's quite
  likely we will replace this with Perfetto in the near future so not
  much point investing in this code right now.
- Enable TracingCpuProfiler test which was flaky due to these bugs.

Bug: v8:8821
Change-Id: I141296800c6906ac0e7f3f21dd16d861b07dae62
Reviewed-on: https://chromium-review.googlesource.com/c/1477283
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Ali Ijaz Sheikh <ofrobots@google.com>
Cr-Commit-Position: refs/heads/master@{#59752}

Bug: v8:7790
Change-Id: I92657d3aae6ba34b2aeeb6f000962707577811b6
Reviewed-on: https://chromium-review.googlesource.com/c/1478696Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59751}

In the Crankshaft days we (mis)used the Representation to also express
the various internal representations that the compiler understands. But
with TurboFan we now have proper MachineRepresentation and MachineType,
which do that independently. So there's no need to have this in the
Representation class anymore, and instead the Representation class only
needs to deal with the field representations.

Bug: v8:8749, v8:8834, v8:8865
Change-Id: I34ea9558b5fdf20d6c7939b52762eaffd4316b06
Reviewed-on: https://chromium-review.googlesource.com/c/1479954
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59750}

Bug: chromium:933331
Change-Id: I598a32b1efe2d4b7e8278ddf84140c72f787afa8
Reviewed-on: https://chromium-review.googlesource.com/c/1475496Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59749}

This is a reland of 1fdf6405

Original change's description:
> Make format torque tools work on win
>
> Reformatting Torque file is required to upload a CL
> but it can only work on POSIX
>
> Change-Id: I51283e3f6b29abf492be7efb5b8f10454d09fb37
> Reviewed-on: https://chromium-review.googlesource.com/c/1475919
> Reviewed-by: Michael Stanton <mvstanton@chromium.org>
> Commit-Queue: Michael Stanton <mvstanton@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#59719}

Change-Id: I09a19a9989091205eb413fd60b2e8bec289092fd
Reviewed-on: https://chromium-review.googlesource.com/c/1479530
Commit-Queue: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59748}

Change-Id: I808ce4d0089accd3f6afaeab98bd6237e169f793
Reviewed-on: https://chromium-review.googlesource.com/c/1475915
Commit-Queue: Matt Gardner <magardn@microsoft.com>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59747}

Throw error when accessing private field on super.

Bug: v8:8872
Change-Id: Iad383890fafbdccdd6b6b75a8f9eb32c9d6f5044
Reviewed-on: https://chromium-review.googlesource.com/c/1478219Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59746}

New tests added for these calls:

* evaluateOnCallFrame
* setAsyncCallStackDepth
* setBreakpoint
* setVariableValue

For setAsyncCallStackDepth, this change updates the test to manufacture async callstacks in a different way so that there is more than one. The previous promise chain method was broken by f61facfd.

Change-Id: I9083b0b1c08849d4c7ebb5349cfa4489f551aa39
Reviewed-on: https://chromium-review.googlesource.com/c/1465118
Commit-Queue: Jeff Fisher <jeffish@microsoft.com>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59745}

Currently, it is possible to make the Torque compiler emit uncompilable
C++ code if a 'generates' clause is missing. Rather than making the
developer spelunk through generated code to find out what went wrong,
we can catch this error earlier and print a useful message.

Bug: v8:7793
Change-Id: I49fabc1d39f398bf322523901941494b8dab0506
Reviewed-on: https://chromium-review.googlesource.com/c/1477964Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#59744}

I missed this one in my previous CL.

R=jarin@chromium.org

Change-Id: Ie4b912ee7e3367da48c0d4b092ad09e3f81de788
Reviewed-on: https://chromium-review.googlesource.com/c/1477677Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59743}

Bug: v8:7468
Change-Id: I4e0d99b8ea4580b9cf7abb57f3d6974dd98041e5
Reviewed-on: https://chromium-review.googlesource.com/c/1478215Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59742}

The test started passing on android arm64 after
https://chromium-review.googlesource.com/c/1477736

Change-Id: I52e8372678e37b68d2af4d53b06025ed3660f159
Reviewed-on: https://chromium-review.googlesource.com/c/1478206Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59741}

This reverts commit bd45b89e.

Reason for revert: Android Arm64 failures ( https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8%20Android%20Arm64%20-%20N5X/3243)

Original change's description:
> Roll ICU to 07e7295d from 960f195
> 
>  https://chromium.googlesource.com/chromium/deps/icu.git/+log/07e7295d..960f195
> 
> The following change includes:
> 
>   960f195 Cherry-pick 3 locale fixes
> 
> Bug: v8:8242,v8:8260
> Change-Id: I0b0641db5c75d2ce926dce0e30162f0f6c106ebe
> Reviewed-on: https://chromium-review.googlesource.com/c/1476290
> Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
> Commit-Queue: Frank Tang <ftang@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#59711}

TBR=jshin@chromium.org,gsathya@chromium.org,ftang@chromium.org

Change-Id: I5b9ff7e27e12663ac63063c945608a7abfa2cecf
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8242, v8:8260
Reviewed-on: https://chromium-review.googlesource.com/c/1478208Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59740}

Adds the src side definitions for integrating
"V8 Linux64 GC Stress - custom snapshot" waterfall bot into the try jobs.

R=machenbach@chromium.org
CC=​yangguo@chromium.org,sergiyb@chromium.org

Bug: v8:8718
No-Try: true
Change-Id: Ie75846486b15127ea35ef6bbd478beb513f6d299
Reviewed-on: https://chromium-review.googlesource.com/c/1478194
Commit-Queue: Tamer Tas <tmrts@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Sergiy Belozorov <sergiyb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59739}

This extends the "test-jump-table-assembler" stress test to supported
architectures. Note that on both PPC and S390 the tests flushes out the
race during jump table patching pretty reliably. Fixing this issue is
outside the scope of this change, this just ensures test coverage exists
but keeps the test in question disabled.

R=clemensh@chromium.org
TEST=cctest/test-jump-table-assembler
BUG=v8:8018

Change-Id: Ia299ed2a42f9858019627270a25026b53f3628d3
Reviewed-on: https://chromium-review.googlesource.com/c/1478200Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59738}

Those shard configs should stay in sync with master builders.

NOTRY=true
TBR=sergiyb@chromium.org

Change-Id: I083a4eed8ded884ad8345ba65153f424c9f0ef2f
Reviewed-on: https://chromium-review.googlesource.com/c/1475536Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59737}

This reverts commit 1fdf6405.

Reason for revert: Alters behavior on linux; we need to investigate

Original change's description:
> Make format torque tools work on win
> 
> Reformatting Torque file is required to upload a CL
> but it can only work on POSIX
> 
> Change-Id: I51283e3f6b29abf492be7efb5b8f10454d09fb37
> Reviewed-on: https://chromium-review.googlesource.com/c/1475919
> Reviewed-by: Michael Stanton <mvstanton@chromium.org>
> Commit-Queue: Michael Stanton <mvstanton@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#59719}

TBR=mvstanton@chromium.org,bmsdave@gmail.com,duongn@microsoft.com

Change-Id: I8845fa1d1ddf5ce841a84ef59c9572673e4a2510
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/1478199Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59736}

This reverts commit 0052f12a.

Reason for revert: Fix available

Original change's description:
> [torque] Temporarily disable torque format check to pass presubmit
> 
> Revert this once the bug is fixed.
> 
> Change-Id: I28490ecc9290b5c1f09e1ee8bcd8b600f79f017d
> Bug: v8:8873
> Notry: true
> Notreechecks: true
> Reviewed-on: https://chromium-review.googlesource.com/c/1477747
> Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
> Reviewed-by: Michael Achenbach <machenbach@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#59720}

TBR=machenbach@chromium.org,sigurds@chromium.org,tebbi@chromium.org

Change-Id: I1a51ee93d7adbd1f14103da68e64548141163706
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8873
Reviewed-on: https://chromium-review.googlesource.com/c/1478198Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59735}

This reverts commit 91213b5c.

Reason for revert: Fix available

Original change's description:
> [torque] Temporarily remove torque format check to pass presubmit
> 
> Revert this once the bug is fixed.
> 
> TBR=machenbach@chromium.org
> 
> Change-Id: I32c9ef41b968e37b6de9eddb7e4e27c1d60c87c8
> Bug: v8:8873
> Notry: true
> Notreechecks: true
> Reviewed-on: https://chromium-review.googlesource.com/c/1477749
> Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
> Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#59721}

TBR=sigurds@chromium.org

Change-Id: Icf4454ca9ed1d276fe0a0a3fa0bba3553a6b8a87
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8873
Reviewed-on: https://chromium-review.googlesource.com/c/1478197Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59734}

Bug: v8:7793
Change-Id: I41382177f44b090e51b3a61f29dc9f54bdfad72e
Reviewed-on: https://chromium-review.googlesource.com/c/1475534
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Daniel Clifford <danno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59733}

This reverts commit 5a161ce3.

Reason for revert: Fix is available

Original change's description:
> [torque] Temporarily remove torque format check to pass presubmit
> 
> .. also from v8_presubmit.py
> 
> Revert this once the bug is fixed.
> 
> TBR=machenbach@chromium.org
> 
> Change-Id: I82f443e1d6bea4c4c43d50631f559b3aa25f8410
> Bug: v8:8873
> Notry: true
> Notreechecks: true
> Reviewed-on: https://chromium-review.googlesource.com/c/1478690
> Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
> Reviewed-by: Michael Achenbach <machenbach@chromium.org>
> Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#59722}

TBR=machenbach@chromium.org,sigurds@chromium.org

Change-Id: I9b8f01e9563cc53d34c0835872fb6fe8b5ddb240
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8873
Reviewed-on: https://chromium-review.googlesource.com/c/1478195Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59732}

Bug: chromium:932392
Change-Id: Icf5690585303a7f61421bdfe7729823c98950d13
Reviewed-on: https://chromium-review.googlesource.com/c/1478192Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59731}

This is a reland of 6202c445.
Moved skipped test from 'variant == jitless' to
'lite_mode or variant == jitless'.

Original change's description:
> [inspector] Add wasm profiling test
>
> This adds a first simple test to check that CPU profiles contain wasm
> function names.
>
> R=herhut@chromium.org, kozyatinskiy@chromium.org
>
> Bug: v8:8783
> Change-Id: I26b1fd2b7ec555c073d80a464ee8a799b017b07a
> Reviewed-on: https://chromium-review.googlesource.com/c/1454597
> Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
> Reviewed-by: Stephan Herhut <herhut@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#59703}

TBR=herhut@chromium.org

Bug: v8:8783
Change-Id: I4f68db86bf1caa4f0d68dd4fa227ded25bf5145a
Reviewed-on: https://chromium-review.googlesource.com/c/1477678Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59730}

This introduces a new {base::SharedMutex}, which mimics
{std::shared_mutex}, available in C++17.
It is being used for synchronizing the WebAssembly background compile
tasks. This removes a lot of unnecessary contention, leading to
synchronization of background tasks that should be able to run in
parallel ideally.
Locally, this reduces Liftoff compilation time by more than 20 percent.

R=mstarzinger@chromium.org, mlippautz@chromium.org

Bug: chromium:924956
Cq-Include-Trybots: luci.v8.try:v8_linux64_tsan_rel
Change-Id: I8c522faf385149bfe2cf00d777a7942c537f9cd2
Reviewed-on: https://chromium-review.googlesource.com/c/1477731
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59729}

This is a reland of c9ef0405

Original change's description:
> [builtins]: Optimize CreateTypedArray to use element size log 2 for calculations.
>
> TypedArrayElementsInfo now represents an element's size as a log 2 and typed as
> uintptr.  This simplifies and speeds up (avoids possible HeapNumber allocations) a
> number of calculations:
>
>   - Number of Elements (length) -> Byte Length - is now a WordShl
>   - Byte Length -> Number of Elements (length) - is now a WordShr
>   - Testing alignment (byte offset or length)  - is now a WordAnd
>
> These element/byte length related calculations are encapsulated in
> TypedArrayElementsInfo as struct methods.
>
> This reduces the size of CreateTypedArray by 2.125 KB (24%) on Mac x64.release:
>   - Before: 9,088
>   - After:  6,896
>
> This improves the performance of the following microbencmarks
>   - TypedArrays-ConstructWithBuffer: ~87%
>   - TypedArrays-SubarrayNoSpecies:   ~28%
>
> Bug: v8:7161
> Change-Id: I2239fd0e0af9d3ad55cd52318088d3c7c913ae44
> Reviewed-on: https://chromium-review.googlesource.com/c/1456299
> Commit-Queue: Peter Wong <peter.wm.wong@gmail.com>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Simon Zünd <szuend@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#59531}

Bug: v8:7161, chromium:932034
Change-Id: I5c3dc34c549234417f95b404e7d49b2fd496fa69
Reviewed-on: https://chromium-review.googlesource.com/c/1476306
Commit-Queue: Peter Wong <peter.wm.wong@gmail.com>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59728}

Since these Recheck() calls are usually combined with a bailout,
doing them at the end of loops means we have to increment one or
more bailout variables, which is hard to understand.

Change-Id: I595ea592f31762da5abd85bfa7556eb39e3c9430
Reviewed-on: https://chromium-review.googlesource.com/c/1478694Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59727}

The ReplacementStringBuilder had a tricky API that required manually
growing the backing store if needed. This saves a few int additions
and comparisons, but is probably not worth the potential for errors.
This CL changes to automatic growth that is invisible to the user.

Bug: chromium:933521
Change-Id: I7d2404a48fe47ccce9af919910c06a9eca598120
Reviewed-on: https://chromium-review.googlesource.com/c/1477748Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59726}

This reverts commit f8962ae1.

Reason for revert: breaks Arm bots, e.g. https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8%20Arm/9655, task: https://chromium-swarm.appspot.com/task?d=true&id=431dfa503db16d10

Original change's description:
> Preparing v8 to use with python3 /test
> 
> There are now less that 400 days until the end of life
> of Python 2(aka _legacy_ Python) https://pythonclock.org/ .
> The code compatibility check for python2 and python3
> used the following tools: futurize, flake8
> You can see the reports here: https://travis-ci.com/bmsdave/v8/builds
> 
> This CL was uploaded by git cl split.
> 
> Bug: v8:8594
> Change-Id: Idbf467daf629a4e808345a6a88036c2a3f259138
> Reviewed-on: https://chromium-review.googlesource.com/c/1470121
> Commit-Queue: Michael Achenbach <machenbach@chromium.org>
> Reviewed-by: Michael Achenbach <machenbach@chromium.org>
> Reviewed-by: Sergiy Belozorov <sergiyb@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#59679}

TBR=machenbach@chromium.org,sergiyb@chromium.org,herhut@chromium.org,bmsdave@gmail.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: v8:8594
Change-Id: I17a0a7b203fa2c0ab0f965240ee1415b7513e1cf
Reviewed-on: https://chromium-review.googlesource.com/c/1478692Reviewed-by: Sergiy Belozorov <sergiyb@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Sergiy Belozorov <sergiyb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59725}

On Intel processors it seems to be generally beneficial to use pushes
instead of explicit stack massaging to allocate the function callback
arguments on the stack for the API callback.

This yields a 5% improvement on the API callback performance, and
recovers an earlier regression (which was probably due to changing this
code to use movs instead of pushes).

Bug: v8:8820, v8:8848, chromium:913553
Change-Id: I3a82cf9bd49498728cae579dd39a9a3cfef37cea
Reviewed-on: https://chromium-review.googlesource.com/c/1477745Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59724}

NOTRY=true

Bug: v8:3770
Change-Id: I2357aae4f6be8158cb5fd75e467aa943f4929abe
Reviewed-on: https://chromium-review.googlesource.com/c/1477281Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59723}

.. also from v8_presubmit.py

Revert this once the bug is fixed.

TBR=machenbach@chromium.org

Change-Id: I82f443e1d6bea4c4c43d50631f559b3aa25f8410
Bug: v8:8873
Notry: true
Notreechecks: true
Reviewed-on: https://chromium-review.googlesource.com/c/1478690Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59722}