Evacuating and compacting LayoutDescriptor is meta-circular, i.e., we
need the descriptor to iterate the objects that are copied. Separate the
phases to avoid requiring a publishing store for object payloads.

This reverts commit 6f4a86c1.

CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel

Bug: v8:6884
Change-Id: I71472eaf7671ede20ff4b19f1f0c9490cdb0b629
Reviewed-on: https://chromium-review.googlesource.com/702255Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48307}

Change-Id: Ib36b6e27476f7cc1e2064e147fbfa7d3d1e28b49

These will be used in subsequent CLs to add spec-compliant builtins
on Array.prototype built with the CSA.

Change-Id: Ib36b6e27476f7cc1e2064e147fbfa7d3d1e28b49
Reviewed-on: https://chromium-review.googlesource.com/700694
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48306}

Some comments to clarify the structure of Map objects
for new contributors (and myself).

BUG=
R=adamk@chromium.org, verwaest@chromium.org, littledan@chromium.org

Change-Id: I5b107e2917440a18888599f52f53f0cb07902ab0
Reviewed-on: https://chromium-review.googlesource.com/675565
Commit-Queue: Caitlin Potter <caitp@igalia.com>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48305}

Change-Id: Idd8b5c30607575e3cb5e54177308e68183aa78bb
Reviewed-on: https://chromium-review.googlesource.com/700676Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Daniel Clifford <danno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48304}

This reverts commit d0651bd1.

Reason for revert: Breaks gc stress with embedded snapshot:
https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20GC%20Stress%20-%20custom%20snapshot/builds/15355

Original change's description:
> [language] Implement optional catch binding proposal
> 
> This allows the syntax `try {} catch {}` (with no binding after the
> `catch`).
> 
> See https://github.com/michaelficarra/optional-catch-binding-proposal/
> 
> Currently behind --harmony-optional-catch-binding.
> 
> As part of the implementation, this allows TryCatchStatements to not
> have an associated catch scope; various paths which assumed they
> would have been updated to handle this case.
> 
> Cq-Include-Trybots: master.tryserver.v8:v8_linux_noi18n_rel_ng
> Change-Id: Ic525b45199eef025eb05da562e10fbd4f3d7465f
> Reviewed-on: https://chromium-review.googlesource.com/571453
> Reviewed-by: Marja Hölttä <marja@chromium.org>
> Reviewed-by: Adam Klein <adamk@chromium.org>
> Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Commit-Queue: Kevin Gibbons <bakkot@gmail.com>
> Cr-Commit-Position: refs/heads/master@{#48300}

TBR=rmcilroy@chromium.org,adamk@chromium.org,marja@chromium.org,gsathya@chromium.org,bakkot@gmail.com

Change-Id: I63d68160ec75b87e28d3dcdddca2d8b7d0503b46
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Cq-Include-Trybots: master.tryserver.v8:v8_linux_noi18n_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/702334Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48303}

This reverts commit 0f5d3ed1.

Reason for revert: Reland button relands right away...

Original change's description:
> [heap] Separate map space pointers updating from main bulk
> 
> Evacuating and compacting LayoutDescriptor is meta-circular, i.e., we
> need the descriptor to iterate the objects that are copied. Separate the
> phases to avoid requiring a publishing store for object payloads.
> 
> Bug: v8:6884
> Change-Id: Icc3bb80a938fbd9eec60c79d88ab8fdd9bda0840
> Reviewed-on: https://chromium-review.googlesource.com/700437
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#48288}

TBR=ulan@chromium.org,mlippautz@chromium.org

Change-Id: Ie91ef6ea5a55f4e8165b3fa97b2c2042376998f1
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:6884
Reviewed-on: https://chromium-review.googlesource.com/701756Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48302}

Sometimes, the embedder might want to merge a fix to an abandoned branch
or to a supported branch but the fix is not relevant to Chromium.
This adds a new version string that the embedder can set at compile time
and that will be appended to the official V8 version.
The separator must be provided in the string. For instance, to have a
full version string like "6.0.287.53-emb.1", the embedder must set
V8_EMBEDDER_STRING to "-emb.1".

Related Node.js issue: https://github.com/nodejs/node/pull/9754

BUG=v8:5740
R=machenbach@chromium.org

Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: Ifa2d9bd213795e6d54886436f8c3787ac6162823
Reviewed-on: https://chromium-review.googlesource.com/690475Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Michaël Zasso <mic.besace@gmail.com>
Cr-Commit-Position: refs/heads/master@{#48301}

This allows the syntax `try {} catch {}` (with no binding after the
`catch`).

See https://github.com/michaelficarra/optional-catch-binding-proposal/

Currently behind --harmony-optional-catch-binding.

As part of the implementation, this allows TryCatchStatements to not
have an associated catch scope; various paths which assumed they
would have been updated to handle this case.

Cq-Include-Trybots: master.tryserver.v8:v8_linux_noi18n_rel_ng
Change-Id: Ic525b45199eef025eb05da562e10fbd4f3d7465f
Reviewed-on: https://chromium-review.googlesource.com/571453Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Kevin Gibbons <bakkot@gmail.com>
Cr-Commit-Position: refs/heads/master@{#48300}

Bug: v8:6791
Change-Id: I5e91832bcb74e895eaf7a3d6ee493c832abba7bf
Reviewed-on: https://chromium-review.googlesource.com/699635
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48299}

Previously, we would first fire the PromiseRejectCallback before
fulfilling the promise. This patch changes the behavior to first
fulfill the promise. This behavior is more intuitive.

This patch also merges the check for PromiseHook callback with the
debug callback, since they use the same boolean bit on the isolate.

Bug: v8:6880
Change-Id: Ia04867e16423a1d6006f0f3f93a14fa6026e17ed
Reviewed-on: https://chromium-review.googlesource.com/700980
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48298}

CCalls have significantly less overhead than runtime calls which will improve
runtime performance on programs that make lots of transitions between JS and
Wasm.

Bug: v8:5277
Change-Id: If09dea97f24eb43753847e2b894ebc1ba5168c23
Reviewed-on: https://chromium-review.googlesource.com/688481
Commit-Queue: Eric Holk <eholk@chromium.org>
Reviewed-by: Mircea Trofin <mtrofin@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48297}

This reverts commit 0f5d3ed1.

Reason for revert: Needs to consider invalidated slots too. Roll flaking on GPU bots: https://chromium-review.googlesource.com/c/chromium/src/+/700721

Original change's description:
> [heap] Separate map space pointers updating from main bulk
> 
> Evacuating and compacting LayoutDescriptor is meta-circular, i.e., we
> need the descriptor to iterate the objects that are copied. Separate the
> phases to avoid requiring a publishing store for object payloads.
> 
> Bug: v8:6884
> Change-Id: Icc3bb80a938fbd9eec60c79d88ab8fdd9bda0840
> Reviewed-on: https://chromium-review.googlesource.com/700437
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#48288}

TBR=ulan@chromium.org,mlippautz@chromium.org

Change-Id: I854687c5e40541c62a0bcf15ad251afe5ddaa8d1
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:6884
Reviewed-on: https://chromium-review.googlesource.com/701534Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48296}

Bug: v8:6791
Change-Id: Id889823ff2cf20cf504010ffce3283f0d75bf72f
Reviewed-on: https://chromium-review.googlesource.com/699420Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48295}

This reverts commit 5e76ff5a.

Reason for revert: tsan failures - https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20TSAN/builds/17574

Original change's description:
> Reland "[wasm] always allocate memory when guard regions are needed"
> 
> This reverts commit 7cf29d8d.
> 
> Original change's description:
> > [wasm] always allocate memory when guard regions are needed
> >
> > When using trap handlers, memory references do not get any checks inserted. This
> > means there is no check for a null memory as happens when the memory size is
> > 0. Normally this would be correctly caught as an out of bounds access, since the
> > low memory addresses are not normally mapped. However, if they were mapped for
> > some reason, we would not catch the out of bounds access.
> >
> > The fix is to ensure WebAssembly instances always have a guard region even if
> > the memory is size 0.
> >
> > Bug: chromium:769637
> 
> Change-Id: I09fdaea92b7ccb3a6cc9e28392171ec098538a00
> Reviewed-on: https://chromium-review.googlesource.com/695812
> Commit-Queue: Eric Holk <eholk@chromium.org>
> Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
> Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#48293}

TBR=gdeepti@chromium.org,mtrofin@chromium.org,mlippautz@chromium.org,eholk@chromium.org,eholk@google.com,clemensh@chromium.org

Change-Id: I52d5354126158a92602b08c48703d562ac95075b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/699599Reviewed-by: Eric Holk <eholk@chromium.org>
Commit-Queue: Eric Holk <eholk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48294}

This reverts commit 7cf29d8d.

Original change's description:
> [wasm] always allocate memory when guard regions are needed
>
> When using trap handlers, memory references do not get any checks inserted. This
> means there is no check for a null memory as happens when the memory size is
> 0. Normally this would be correctly caught as an out of bounds access, since the
> low memory addresses are not normally mapped. However, if they were mapped for
> some reason, we would not catch the out of bounds access.
>
> The fix is to ensure WebAssembly instances always have a guard region even if
> the memory is size 0.
>
> Bug: chromium:769637

Change-Id: I09fdaea92b7ccb3a6cc9e28392171ec098538a00
Reviewed-on: https://chromium-review.googlesource.com/695812
Commit-Queue: Eric Holk <eholk@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48293}

No-try: true
Bug: v8:6886
Change-Id: I994b998e9e5006c6de183328603f3545158bd32c
Reviewed-on: https://chromium-review.googlesource.com/700536Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48292}

Fix an error overwriting the `prototype` property of async generator
functions when FLAG_enable_slow_asserts is enabled.

Previously, the `initial_async_generator_prototype` field was never
written to the native context, and was always undefined. This caused
some incorrect runtime behaviour, and would crash when loading the field
using the Context::initial_aysnc_generator_prototype accessor when
attempting to cast the Undefined oddball to a JSObject.

BUG=chromium:771470, v8:5855
R=adamk@chromium.org, verwaest@chromium.org, gsathya@chromium.org

Change-Id: I13f2a518c59852bc77c2de1f2468a4eea457609e
Reviewed-on: https://chromium-review.googlesource.com/700261Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Caitlin Potter <caitp@igalia.com>
Cr-Commit-Position: refs/heads/master@{#48291}

The code in `AsmJsScanner::Next()` checks for both
end of input and parse error:

  if (token_ == kEndOfInput || token_ == kParseError) {
    return;
  }

but until now the code in the parsing loop only checked
for `kEndOfInput`, resulting in an infinite loop on
`kParseError`.

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

Bug: chromium:771428
Change-Id: I9170f090503590b3b9b949a0d00ab4daef85bf66
Reviewed-on: https://chromium-review.googlesource.com/699994
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48290}

In the process, also enable support for PACKED_DOUBLE_ELEMENTS arrays.

Change-Id: I16dd79276f1023e30b072d45216396533077f53c
Reviewed-on: https://chromium-review.googlesource.com/571006
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48289}

Evacuating and compacting LayoutDescriptor is meta-circular, i.e., we
need the descriptor to iterate the objects that are copied. Separate the
phases to avoid requiring a publishing store for object payloads.

Bug: v8:6884
Change-Id: Icc3bb80a938fbd9eec60c79d88ab8fdd9bda0840
Reviewed-on: https://chromium-review.googlesource.com/700437Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48288}

This speeds up the json parser by 10-20%

Bug: chromium:771227
Change-Id: Ib2392471bdd9ff9041237708cb272229b5ece410
Reviewed-on: https://chromium-review.googlesource.com/700494
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48287}

This CL also removes the v8::internal::wasm::testing namespace, which
had methods that were defined in wasm-module.h, moving them to be
*ForTesting methods on the corresponding WASM heap objects.

R=clemensh@chromium.org

Bug: v8:6877
Change-Id: I1b346ec64d93ee3a122b8f7e69772cfe98371754
Reviewed-on: https://chromium-review.googlesource.com/695523Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48286}

Bug: v8:6644
Change-Id: I5cd713465563f2dc803b175684bf04a05559e653
Reviewed-on: https://chromium-review.googlesource.com/693239
Commit-Queue: Georgia Kouveli <georgia.kouveli@arm.com>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48285}

This CL addresses a couple of minor issues that were in the way of
properly inlining polymorphic constructors calls, i.e. as found in
this common pattern using Symbol.species:

  class A {
    static get [Symbol.species]() { return this; }
    clone() { return new this.constructor[Symbol.species](); }
  }
  class B extends A {
    static get [Symbol.species]() { return this; }
  }

  function foo(o) { return o.clone(); }
  foo(new A());
  foo(new B());

Here the call to this.constructor[Symbol.species]() is the interesting
site. To get this fully inlined, we had to

  - make sure we don't introduce too many CheckHeapObject eagerly that
    block later optimizations (instead we try harder to see whether the
    receiver is already provably a HeapObject), and
  - also update the new.target of polymorphic JSConstruct nodes, when
    it refers to the same node as the target that we're specializing
    to (this way the JSCreate becomes fully inlinable later).

This seems to yield a solid 1.5% on the ARES6 ML benchmark (run via the
d8 cli runner), which confirms the previous profiled estimation. On the
micro-benchmark that specifically measures this feature in isolation we
go from

  testClone: 828 ms.

on V8 ToT as of today and

  testClone: 1439 ms.

on V8 6.1 to

  testClone: 219 ms.

which is a 3.7x improvement, on top of the previous ~2x boost that we
got from inlining the polymorphic symbol lookup.

Bug: v8:6885, v8:6278, v8:6344
Change-Id: Ida7abf683c7879978f181ba7f52a125f4f83ae6f
Reviewed-on: https://chromium-review.googlesource.com/700596Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48284}

This CL speeds up a common pattern found in the React framework:

function f(a, b, c) { ... };
let f_bound = f.bind(this, 1);
let f_bound2 = f_bound(this, 2);

This CL yields roughly a 15x improvement for rebinding a bound function.

Change-Id: I4d8580a5bce422af411148bc6b3e4eb287fac9ce
Reviewed-on: https://chromium-review.googlesource.com/695206
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48283}

This ports:
https://chromium-review.googlesource.com/c/chromium/src/+/696886

Bug: chromium:692940, chromium:524758
Change-Id: I158d996ff76c354b8a672b085d476e9687205034
Reviewed-on: https://chromium-review.googlesource.com/700455Reviewed-by: Sergiy Byelozyorov <sergiyb@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48282}

Reuse existing concurrent marking infrastructure for marking in the
atomic pause.

Details:
- Do not stop concurrent marking when entering the atomic pause.
- Start concurrent marking when it was off. This is required for
  non-incremental MC GCs.
- Use atomic marking state in MC.
- Transition through grey and avoid white->black.

CQ_INCLUDE_TRYBOTS=master.tryserver.v8:v8_linux64_tsan_rel;master.tryserver.v8:v8_linux64_tsan_concurrent_marking_rel_ng;master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel

Bug: chromium:750084
Change-Id: I9f84661e69beac6254494907bdfe94e865b1e3ab
Reviewed-on: https://chromium-review.googlesource.com/690002
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48281}

Add instruction cache flish for wrapper table in module compiler
instance builder. This fixes several failures in mjsunit/wasm
and mjsunit/asm test suites on some MIPS boards.

Bug: 
Change-Id: Ia8b640ad73a078d29f458d55663606dbbe8e387c
Reviewed-on: https://chromium-review.googlesource.com/697807Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Ivica Bogosavljevic <ivica.bogosavljevic@imgtec.com>
Cr-Commit-Position: refs/heads/master@{#48280}

Good thing this class is actually being unused. Vector<T> is iterable,
so it should just be iterated using a foreach loop.

R=mstarzinger@chromium.org

Change-Id: Ieb6729e5b1336888989d5ec6128b0782b158b1f7
Reviewed-on: https://chromium-review.googlesource.com/695525Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48279}

Port for: https://chromium-review.googlesource.com/c/v8/v8/+/608975

In code generator for MIPS32, certain instructions are substituted with
corresponding macro-instructions.

TEST=
BUG=

Change-Id: I2ac47a785f0ea14c448f727da124dc78ea6c81af
Reviewed-on: https://chromium-review.googlesource.com/699998Reviewed-by: Ivica Bogosavljevic <ivica.bogosavljevic@imgtec.com>
Commit-Queue: Ivica Bogosavljevic <ivica.bogosavljevic@imgtec.com>
Cr-Commit-Position: refs/heads/master@{#48278}

Change-Id: Id34d21437b3881d829526b89058f26741bee7acc
Reviewed-on: https://chromium-review.googlesource.com/695327Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Daniel Clifford <danno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48277}

After closer investigation, the crashes / regressions we currently have are not
so bad that we couldn't have the flag on.

BUG=v8:5516

Change-Id: I1b70cf99de1707d659b2e0abcd3678ec71a530bf
Reviewed-on: https://chromium-review.googlesource.com/699997Reviewed-by: Michael Hablich <hablich@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48276}

The Object.is builtin provides an entry point to the abstract operation
SameValue, which properly distinguishes -0 and 0, and also identifies
NaNs. Most of the time you don't need these, but rather just regular
strict equality, but when you do, Object.is(o, -0) is the most readable
way to check for minus zero.

This is for example used in Node.js by formatNumber to properly print -0
for negative zero. However since the builtin thus far implemented as C++
builtin and TurboFan didn't know anything about it, Node.js considering
to go with a more performant, less readable version (which also makes
assumptions about the input value) in

  https://github.com/nodejs/node/pull/15726

until the performance of Object.is will be on par (so hopefully we can
go back to Object.is in Node 9).

This CL ports the baseline implementation of Object.is to CSA, which
is pretty straight-forward since SameValue is already available in
CodeStubAssembler, and inlines a few interesting cases into TurboFan,
i.e. comparing same SSA node, and checking for -0 and NaN explicitly.

On the micro-benchmarks we go from

  testNumberIsMinusZero: 1000 ms.
  testObjectIsMinusZero: 929 ms.
  testObjectIsNaN: 954 ms.
  testObjectIsSame: 793 ms.
  testStrictEqualSame: 104 ms.

to

  testNumberIsMinusZero: 89 ms.
  testObjectIsMinusZero: 88 ms.
  testObjectIsNaN: 88 ms.
  testObjectIsSame: 86 ms.
  testStrictEqualSame: 105 ms.

which is a nice 10x to 11x improvement and brings Object.is on par with
strict equality for most cases.

Drive-by-fix: Also refactor and optimize the SameValue check in the
CodeStubAssembler to avoid code bloat (by not inlining StrictEqual
into every user of SameValue, and also avoiding useless checks).

Bug: v8:6882
Change-Id: Ibffd8c36511f219fcce0d89ed4e1073f5d6c6344
Reviewed-on: https://chromium-review.googlesource.com/700254Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48275}

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/05cc4b1..7311b74

Rolling v8/third_party/catapult: https://chromium.googlesource.com/catapult/+log/3f41f93..672cabd

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

Change-Id: I5663213d2835b02d0ed9c953749cb722b8422a58
Reviewed-on: https://chromium-review.googlesource.com/700015Reviewed-by: v8 autoroll <v8-autoroll@chromium.org>
Commit-Queue: v8 autoroll <v8-autoroll@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48274}

When atomic operations are used in loops, return the correct opcode length
for loop assignment.

Bug=v8:6842,v8:6532

Change-Id: I306db704d8a0baa5d98c05702360e6dfae11cbfa
Reviewed-on: https://chromium-review.googlesource.com/699561Reviewed-by: Brad Nelson <bradnelson@chromium.org>
Commit-Queue: Brad Nelson <bradnelson@chromium.org>
Commit-Queue: Deepti Gandluri <gdeepti@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48273}

For an improved debugging experience.

Bug: v8:6791
Change-Id: Id4f7fea47036e4520e7b24edf34f210b664672bc
Reviewed-on: https://chromium-review.googlesource.com/699427Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48272}

Original Commit Message:
  In the test-run-wasm and test-run-wasm-64 cctests it is not possible to
  call runtime functions. To test traps in these cctests we therefore
  replace the runtime call with a call to a c-callback, followed by a
  return. This CL fixes the problem that the return did not clean up stack
  parameters.

R=joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Change-Id: Ia6b95141341635b769acf12b82b4524a56b12b94
Reviewed-on: https://chromium-review.googlesource.com/698424Reviewed-by: Junliang Yan <jyan@ca.ibm.com>
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#48271}

I'd like to make sure changes to microtask handling do not break debugging.

R=jarin@chromium.org

Change-Id: I983bd3340261e472b22b0d5b6cded60b64b19d38
Reviewed-on: https://chromium-review.googlesource.com/691715Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48270}

Change-Id: I0de0ea0798c39831765bb3c00a00d0df7471bc3b
Reviewed-on: https://chromium-review.googlesource.com/695407Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48269}

THe change in https://chromium-review.googlesource.com/695108 flushed
out an issue with the IC::UpdatePolymorphicIC logic, where we'd try to
stay MONOMORPHIC or POLYMORPHIC as long as the internalized name doesn't
change. But the calling code already does the internalization for keyed
accesses with Strings, so we need to double check that the same
combination of (map, handler) is not already in the list, and properly
go to MEGAMORPHIC state if there's such a pair already.

This seriously tanked the six-speed-object-literals-ext-es5.js benchmark
on AWFY.

Bug: v8:6367, v8:6278, v8:6344
Change-Id: I90ea88d1fe61c165990c0a10d4a8687ffe351986
Reviewed-on: https://chromium-review.googlesource.com/695307Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48268}