Commit Graph

40 Commits

Author SHA1 Message Date
Swapnil Gaikwad
ffa9f163e6 Reland "Update GetIterator bytecode to load and call object[Symbol.iterator]"
This is a reland of 8b89a7c32d

Reland after disabling the test getting deadlocked with '--gc_stress' flag.
The CL was reverted because of the 'wasm/grow-shared-memory' test from
the mjsunit test suite deadlocked for the 'gc_stress' variant. This is
the known issue (v8:9221) and the deadlocking test is now disabled (
1c8981e3f4).


Original change's description:
> Update GetIterator bytecode to load and call object[Symbol.iterator]
>
> The functionality of the GetIterator bytecode introduced previously is
> now extended from loading the @@iterator property to calling the property
> as well. This change basically absorbs the functionality of additional
> two bytecodes - Star, CallProperty0 in the GetIterator bytecode.
> Importantly, this change handles the cases of eager and lazy deoptimization
> in the middle of the bytecode, i.e., lazy deopt for LdaNamedProperty and
> eager deopt of the CallProperty0 bytecode, using the continuation builtins.
> This mechanism can work as a template for the future bytecode that require
> handling such inter-bytecode deopt scenario. The tests evaluating the eager
> and lazy deopt scenarios are also included.
>
> Bug: v8:9489
> Change-Id: I93eb022bbc3d37582407820aa8482a343cac6c12
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1758313
> Commit-Queue: Swapnil Gaikwad <swapnilgaikwad@google.com>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#63528}

Bug: v8:9489,v8:9221
Change-Id: I4286255aef457bfdbbe5eb50fc6dabdf9c0955b1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1787427
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Swapnil Gaikwad <swapnilgaikwad@google.com>
Cr-Commit-Position: refs/heads/master@{#63599}
2019-09-06 13:44:12 +00:00
Francis McCabe
af04a51efd Revert "Update GetIterator bytecode to load and call object[Symbol.iterator]"
This reverts commit 8b89a7c32d.

Reason for revert: GC Stress tests timing out.
See https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20gc%20stress/24272

Original change's description:
> Update GetIterator bytecode to load and call object[Symbol.iterator]
> 
> The functionality of the GetIterator bytecode introduced previously is
> now extended from loading the @@iterator property to calling the property
> as well. This change basically absorbs the functionality of additional
> two bytecodes - Star, CallProperty0 in the GetIterator bytecode.
> Importantly, this change handles the cases of eager and lazy deoptimization
> in the middle of the bytecode, i.e., lazy deopt for LdaNamedProperty and
> eager deopt of the CallProperty0 bytecode, using the continuation builtins.
> This mechanism can work as a template for the future bytecode that require
> handling such inter-bytecode deopt scenario. The tests evaluating the eager
> and lazy deopt scenarios are also included.
> 
> Bug: v8:9489
> Change-Id: I93eb022bbc3d37582407820aa8482a343cac6c12
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1758313
> Commit-Queue: Swapnil Gaikwad <swapnilgaikwad@google.com>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#63528}

TBR=rmcilroy@chromium.org,neis@chromium.org,leszeks@chromium.org,tebbi@chromium.org,swapnilgaikwad@google.com

Change-Id: I9ae475f71275f71f1b9e60b8bf0578e21ce2704b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:9489
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1783736
Reviewed-by: Francis McCabe <fgm@chromium.org>
Commit-Queue: Francis McCabe <fgm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63536}
2019-09-03 23:19:12 +00:00
Swapnil Gaikwad
8b89a7c32d Update GetIterator bytecode to load and call object[Symbol.iterator]
The functionality of the GetIterator bytecode introduced previously is
now extended from loading the @@iterator property to calling the property
as well. This change basically absorbs the functionality of additional
two bytecodes - Star, CallProperty0 in the GetIterator bytecode.
Importantly, this change handles the cases of eager and lazy deoptimization
in the middle of the bytecode, i.e., lazy deopt for LdaNamedProperty and
eager deopt of the CallProperty0 bytecode, using the continuation builtins.
This mechanism can work as a template for the future bytecode that require
handling such inter-bytecode deopt scenario. The tests evaluating the eager
and lazy deopt scenarios are also included.

Bug: v8:9489
Change-Id: I93eb022bbc3d37582407820aa8482a343cac6c12
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1758313
Commit-Queue: Swapnil Gaikwad <swapnilgaikwad@google.com>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63528}
2019-09-03 15:09:36 +00:00
Leszek Swirski
ef2f091f3e [ignition] Avoid possible unnecessary Mov around GetIterator
Wrap the obj and method registers in BuildGetIterator in a register
allocation scope, so that they don't get materialised before the
JumpIfJSReceiver jump if they don't have to.

Bug: v8:9649
Change-Id: I8dfdd06a23c396124c495b5cb83c078080f1a7c9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1768583
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63393}
2019-08-26 09:44:15 +00:00
Swapnil Gaikwad
ac8acab28f Add GetIterator bytecode to load object[Symbol.iterator] in accumulator
This is the first in a series of changes to reduce the number of
bytecodes generated for the iteration protocol based operations.
The GetIterator bytecode introduced in this change currently loads the
@@iterator symbol from an object that was previously done using the
LdaNamedProperty bytecode. This change uses builtin-based mechanism
that would be extended to perform additional operations in the future
on absorbing the bytecodes associated with the GetIterator operation
from the iteration protocol.

Bug: v8:9489
Change-Id: I83b8b55c27bae8260bf227f355eeca1ba80cd8f0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1701852
Commit-Queue: Swapnil Gaikwad <swapnilgaikwad@google.com>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63139}
2019-08-09 07:58:32 +00:00
Leszek Swirski
00a2481a24 [ignition] Move destructuring assignments to bytecode generation
Instead of de-sugaring destructuring assignment in the parser (using the
pattern rewriter), pass the Object/ArrayLiterals through to the bytecode
generator, which can desugar them in-place.

This allows us to decrease the amount of AST node creation, and improve
the generated bytecode using domain-specific knowledge. As a side effect
we partially fix an old execution ordering spec bug.

Currently only implemented for assignments, not declarations, as the
latter has some additional complexity.

Bug: v8:4951
Change-Id: I3d69d232bea2968ef20df68a74014d9e05808cfe
Reviewed-on: https://chromium-review.googlesource.com/c/1375660
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58512}
2019-01-03 09:41:27 +00:00
Hai Dang
5f8a42727d Reland "[interpreter] Add bytecode for leading array spreads."
This is a reland of 1c48d52bb1.

It turned out that IterableToList doesn't always behave according to
the ES operation with the same name. Specifically, it allows holey arrays
to take its fast path, which produces an output array with holes where
actually "undefined" elements should appear.

This CL changes the version of IterableToList that is used for spreads
(IterableToListWithSymbolLookup) such that holey arrays take the slow path.
It also includes tests for such situations.

Original change's description:
> [interpreter] Add bytecode for leading array spreads.
>
> This CL improves the performance of creating [...a, b] or [...a].
> If the array literal has a leading spread, this CL emits the bytecode
> [CreateArrayFromIterable] to create the literal. CreateArrayFromIterable
> is implemented by [IterableToListDefault] builtin to create the initial
> array for the leading spread. IterableToListDefault has a fast path to
> clone efficiently if the spread is an actual array.
>
> The bytecode generated is now shorter. Bytecode generation is refactored
> into to BuildCreateArrayLiteral, which allows VisitCallSuper to benefit
> from this optimization also.
> For now, turbofan also lowers the bytecode to the builtin.
>
> The idiomatic use of [...a] to clone the array a now performs better
> than a simple for-loop, but still does not match the performance of slice.
>
> Bug: v8:7980
>
> Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
> Change-Id: Ibde659c82d3c7aa1b1777a3d2f6426ac8cc15e35
> Reviewed-on: https://chromium-review.googlesource.com/1181024
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Commit-Queue: Georg Neis <neis@chromium.org>
> Commit-Queue: Hai Dang <dhai@google.com>
> Cr-Commit-Position: refs/heads/master@{#55520}

Bug: v8:7980
Change-Id: I0b5603a12d2b588327658bf0a9b214bd0f22e237
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/1201882
Commit-Queue: Hai Dang <dhai@google.com>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55639}
2018-09-05 09:29:51 +00:00
Georg Neis
ef56902851 Revert "[interpreter] Add bytecode for leading array spreads."
This reverts commit 1c48d52bb1.

Reason for revert: Clusterfuzz found something.

Original change's description:
> [interpreter] Add bytecode for leading array spreads.
> 
> This CL improves the performance of creating [...a, b] or [...a].
> If the array literal has a leading spread, this CL emits the bytecode
> [CreateArrayFromIterable] to create the literal. CreateArrayFromIterable
> is implemented by [IterableToListDefault] builtin to create the initial
> array for the leading spread. IterableToListDefault has a fast path to
> clone efficiently if the spread is an actual array.
> 
> The bytecode generated is now shorter. Bytecode generation is refactored
> into to BuildCreateArrayLiteral, which allows VisitCallSuper to benefit
> from this optimization also.
> For now, turbofan also lowers the bytecode to the builtin.
> 
> The idiomatic use of [...a] to clone the array a now performs better
> than a simple for-loop, but still does not match the performance of slice.
> 
> Bug: v8:7980
> 
> Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
> Change-Id: Ibde659c82d3c7aa1b1777a3d2f6426ac8cc15e35
> Reviewed-on: https://chromium-review.googlesource.com/1181024
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Commit-Queue: Georg Neis <neis@chromium.org>
> Commit-Queue: Hai Dang <dhai@google.com>
> Cr-Commit-Position: refs/heads/master@{#55520}

TBR=rmcilroy@chromium.org,neis@chromium.org,sigurds@chromium.org,gsathya@chromium.org,jgruber@chromium.org,dhai@google.com

Change-Id: I1c86ddcc24274da9f5a8dd3d8bf8d869cbb55cb6
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7980
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/1199303
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55544}
2018-08-31 11:43:33 +00:00
Hai Dang
1c48d52bb1 [interpreter] Add bytecode for leading array spreads.
This CL improves the performance of creating [...a, b] or [...a].
If the array literal has a leading spread, this CL emits the bytecode
[CreateArrayFromIterable] to create the literal. CreateArrayFromIterable
is implemented by [IterableToListDefault] builtin to create the initial
array for the leading spread. IterableToListDefault has a fast path to
clone efficiently if the spread is an actual array.

The bytecode generated is now shorter. Bytecode generation is refactored
into to BuildCreateArrayLiteral, which allows VisitCallSuper to benefit
from this optimization also.
For now, turbofan also lowers the bytecode to the builtin.

The idiomatic use of [...a] to clone the array a now performs better
than a simple for-loop, but still does not match the performance of slice.

Bug: v8:7980

Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: Ibde659c82d3c7aa1b1777a3d2f6426ac8cc15e35
Reviewed-on: https://chromium-review.googlesource.com/1181024
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Commit-Queue: Hai Dang <dhai@google.com>
Cr-Commit-Position: refs/heads/master@{#55520}
2018-08-30 11:47:58 +00:00
Creddy
bb0975878f [runtime][parser] Use ArrayBoilerplateDescription all the way
* Rename BoilerplateDescription to ObjectBoilerplateDescription
* Add literal_type flag to ObjectBoilerplateDescription,
  which is stored as zeroth element of Fixed array
* Create ArrayBoilerplateDescription with elements_kind and
  constant_elements field
* Replace CompileTimeValue and ConstantElementPair with
  ArrayBoilerplateDescription
* Kill ConstantElementPair and CompileTimeValue

Change-Id: Icb42dcfd575a27e2b64ffd5e2e61f9d703d5e986
Bug: v8:7787, chromium:818642
Reviewed-on: https://chromium-review.googlesource.com/1122411
Commit-Queue: Chandan Reddy <chandanreddy@google.com>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54272}
2018-07-05 19:31:03 +00:00
Georg Neis
cf8cd1c444 [interpreter] Only create spread-related feedback slots when necessary.
Only create spread-related feedback slots when the array literal
actually contains a spread.

Bug: v8:5940
Change-Id: I0afad81d4bf1a86ebc1bf81f1213f680eb22bc49
Reviewed-on: https://chromium-review.googlesource.com/947955
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51721}
2018-03-05 11:01:32 +00:00
Georg Neis
2e2860f74f [ic] Introduce new IC for storing into array literals.
... and use it in the implementation of array literal spreads,
replacing calls to %AppendElement.

Array spreads in destructuring will be taken care of in a separate CL.

Bug: v8:5940, v8:7446
Change-Id: Idec52398902a7fd3c1244852cf73246f142404f0
Reviewed-on: https://chromium-review.googlesource.com/915364
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51709}
2018-03-02 21:12:57 +00:00
Georg Neis
82345e9fbf Reland "[parsing] inline ArrayLiteral creation for spread calls"
This reverts commit f48e734903.

Reason for revert: innocent!!

Original change's description:
> Revert "[parsing] inline ArrayLiteral creation for spread calls"
> 
> This reverts commit 93fc3841c3.
> 
> Reason for revert: may break node.js integration
> 
> Original change's description:
> > [parsing] inline ArrayLiteral creation for spread calls
> > 
> > Instead of using runtime calls to generate the Array Literal passed to
> > %reflect_call / %reflect_construct, we create an ArrayLiteral from the
> > list of arguments, and perform spreads using the interpreter mechanism for
> > spreading in ArrayLiterals (thus, the spreading becomes inline). This
> > array literal is still passed to %reflect_call / %reflect_construct as
> > before.
> > 
> > This cuts the runtime for bench-spread-call.js -> testSpread roughly in
> > half, and will likely improve further once
> > https://chromium-review.googlesource.com/c/v8/v8/+/915364 has landed.
> > 
> > BUG=v8:7446
> > R=​neis@chromium.org, adamk@chromium.org
> > 
> > Change-Id: I74a6acd3a60aad422e4ac575275c7b567659d8ad
> > Reviewed-on: https://chromium-review.googlesource.com/939587
> > Commit-Queue: Georg Neis <neis@chromium.org>
> > Reviewed-by: Georg Neis <neis@chromium.org>
> > Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#51678}
> 
> TBR=adamk@chromium.org,neis@chromium.org,caitp@igalia.com,bmeurer@chromium.org
> 
> Change-Id: I4730077591bce0e5e7b2ce7d59678e8b7135cc08
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: v8:7446
> Reviewed-on: https://chromium-review.googlesource.com/945769
> Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
> Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#51682}

TBR=adamk@chromium.org,neis@chromium.org,sigurds@chromium.org,caitp@igalia.com,bmeurer@chromium.org

Change-Id: I977513bea06a4f3fba03fa4a89270298475422e2
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7446
Reviewed-on: https://chromium-review.googlesource.com/945808
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51686}
2018-03-02 10:03:42 +00:00
Sigurd Schneider
f48e734903 Revert "[parsing] inline ArrayLiteral creation for spread calls"
This reverts commit 93fc3841c3.

Reason for revert: may break node.js integration

Original change's description:
> [parsing] inline ArrayLiteral creation for spread calls
> 
> Instead of using runtime calls to generate the Array Literal passed to
> %reflect_call / %reflect_construct, we create an ArrayLiteral from the
> list of arguments, and perform spreads using the interpreter mechanism for
> spreading in ArrayLiterals (thus, the spreading becomes inline). This
> array literal is still passed to %reflect_call / %reflect_construct as
> before.
> 
> This cuts the runtime for bench-spread-call.js -> testSpread roughly in
> half, and will likely improve further once
> https://chromium-review.googlesource.com/c/v8/v8/+/915364 has landed.
> 
> BUG=v8:7446
> R=​neis@chromium.org, adamk@chromium.org
> 
> Change-Id: I74a6acd3a60aad422e4ac575275c7b567659d8ad
> Reviewed-on: https://chromium-review.googlesource.com/939587
> Commit-Queue: Georg Neis <neis@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#51678}

TBR=adamk@chromium.org,neis@chromium.org,caitp@igalia.com,bmeurer@chromium.org

Change-Id: I4730077591bce0e5e7b2ce7d59678e8b7135cc08
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7446
Reviewed-on: https://chromium-review.googlesource.com/945769
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51682}
2018-03-02 09:29:32 +00:00
Caitlin Potter
93fc3841c3 [parsing] inline ArrayLiteral creation for spread calls
Instead of using runtime calls to generate the Array Literal passed to
%reflect_call / %reflect_construct, we create an ArrayLiteral from the
list of arguments, and perform spreads using the interpreter mechanism for
spreading in ArrayLiterals (thus, the spreading becomes inline). This
array literal is still passed to %reflect_call / %reflect_construct as
before.

This cuts the runtime for bench-spread-call.js -> testSpread roughly in
half, and will likely improve further once
https://chromium-review.googlesource.com/c/v8/v8/+/915364 has landed.

BUG=v8:7446
R=neis@chromium.org, adamk@chromium.org

Change-Id: I74a6acd3a60aad422e4ac575275c7b567659d8ad
Reviewed-on: https://chromium-review.googlesource.com/939587
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51678}
2018-03-02 08:44:26 +00:00
Ross McIlroy
ed592eb03f [Cleanup][Interpreter] Move feedback slot allocation to bytecode generator
Moves the feedback vector slot allocation out of ast-numbering and into
bytecode generation directly. This has a couple of benifits, including reduced
AST size, avoid code duplication and reduced feedback vector sizes in many cases
due to only allocating slots when needed. Also removes AstProperties since
this is no longer needed.

AstNumbering is now only used to allocate suspend ids for generators.

BUG=v8:6921

Change-Id: I103e8593c94ef5b2e56c34ef4f77bd6e7d64796f
Reviewed-on: https://chromium-review.googlesource.com/722959
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48757}
2017-10-19 16:17:14 +00:00
Ross McIlroy
a192639e2f [Interpreter] Make CallJSRuntime implicitly use undefined reciever.
JS runtime calls are always created with undefined recievers, so make the
bytecode behave similarly to CallUndefinedReciever such that we don't need
to push an explicit undefined register for the receiver for such calls.

Modifies the Async[Generator/Function]Await[Caught/Uncaught] runtime calls
to pass the generator in the first argument rather than the reciever since
these runtime calls were desugered in the bytecode generator and explicitly
passed the generator in the receiver.

Change-Id: I36c8087bb3b663dccd805bfdb1eea04eb6a73269
Reviewed-on: https://chromium-review.googlesource.com/654257
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47870}
2017-09-07 12:14:24 +00:00
Leszek Swirski
37680d6563 [objects] Make feedback vector a first-class object
Instead of having feedback vector as a subtype of FixedArray with
reserved slots, make it a first-class variable-sized object with a
fixed-size header. This allows us to compress counters to ints in the
header, rather than forcing them to be Smis.

Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: Icc5f088ffbc2e2651b845bc71ea42060639e3e48
Reviewed-on: https://chromium-review.googlesource.com/585129
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46935}
2017-07-27 13:31:55 +00:00
Leszek Swirski
661726dd39 [runtime] Move profiler ticks from SFI to feedback vector (reland)
Reland of https://chromium-review.googlesource.com/c/544888/.

Instead of counting profiler ticks on the shared function info (which is
shared between native contexts), count them on the feedback vector
(which is not). This allows us to continue pushing optimization
decisions off the SFI, onto the feedback vector.

Note that a side-effect of this is that ICs don't have to walk the stack
to reset profiler ticks, as they can access the feedback vector directly
from their feedback nexus.

Change-Id: I7aa6baed03f726843d1b62629c72b74f05114b48
Reviewed-on: https://chromium-review.googlesource.com/579051
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46868}
2017-07-25 11:54:21 +00:00
Benedikt Meurer
5ee1b7ad5a [turbofan] Add IC support for Call/ConstructWithSpread.
Properly hook up the (existing) IC slots for the CallWithSpread and
ConstructWithSpread bytecodes, and change the interpreter to collect
feedback (call counts and regular target function feedback) for those.
There's no integration with the Array constructor yet, since that
requires some yak shaving to thread through the AllocationSite to the
Array constructor stub. Once we have a solution for that, we can also
remove the current code duplication in the Call/Construct IC logic.

Also properly hook up the newly available feedback in TurboFan. This
will fix not only the missing target feedback, but more importantly
the tear-up decisions for optimization are correct now in the presence
of spread calls, and even more importantly the inlining heurstic has
proper call frequencies for those.

Some follow-up changes will be necessary to make sure we use the
feedback even for corner cases that aren't handled properly yet. Also
we should consider collecting feedback about the map of the spread
at some point to be able to always inline the spread calls.

Bug: v8:6399, v8:6527, v8:6630
Change-Id: I818dbcb411fd3951d8e9d31f5d7e794f8d60fa00
Reviewed-on: https://chromium-review.googlesource.com/582647
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46832}
2017-07-24 07:11:50 +00:00
Leszek Swirski
14c5c4fde7 Revert "[runtime] Move profiler ticks from SFI to feedback vector"
This reverts commit a2fcdc7cc8.

Reason for revert: Large regressions in RCS (https://chromeperf.appspot.com/group_report?bug_id=740126)

Original change's description:
> [runtime] Move profiler ticks from SFI to feedback vector
> 
> Instead of counting profiler ticks on the shared function info (which is
> shared between native contexts), count them on the feedback vector
> (which is not). This allows us to continue pushing optimization
> decisions off the SFI, onto the feedback vector.
> 
> Note that a side-effect of this is that ICs don't have to walk the stack
> to reset profiler ticks, as they can access the feedback vector directly
> from their feedback nexus.
> 
> Change-Id: I232ae9e759fca75cd89d393148a4ff42caa2646f
> Reviewed-on: https://chromium-review.googlesource.com/544888
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#46411}

TBR=rmcilroy@chromium.org,leszeks@chromium.org,ishell@chromium.org

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

Change-Id: Id587e4172e300c420f93c49744a2a0e66696edf8
Reviewed-on: https://chromium-review.googlesource.com/574227
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46702}
2017-07-17 11:51:32 +00:00
Camillo Bruni
36421dc467 [literals] Disable double lazy boilerplate for literals containing Arrays
By creating the boilerplate only on the second instantiation we cannot
propagate back the elements transitions early enough. The resulting literals
would change the initial ElementsKind one step too late and already pollute
ICs that went to monomorphic state.

- Disable lazy AllocationSites for literals containing arrays
- Introduce new ComplexLiteral class to share code between ObjectLiteral
  and ArrayLiteral
- RegexpLiteral now no longer needs a depth_ field

Bug: v8:6517, v8:6519, v8:6211
Change-Id: Ia88d1878954e8895c3d00a7dda8d71e95bba005c
Reviewed-on: https://chromium-review.googlesource.com/563305
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46603}
2017-07-12 19:11:04 +00:00
Alexey Kozyatinskiy
61ea32436d Reland "[parser] moved load property position after dot"
This is a reland of 5b44ba0e34
Original change's description:
> (Reland) [parser] moved load property position after dot
> 
> Currently LdaNamedProperty bytecode for expressions like a.b has position before dot. This CL moves this location after dot.
> It's important for later removing of Nop bytecodes in expressions like a.b() where a is local variable, property call and property load should have the same position.
> 
> R=jgruber@chromium.org
> TBR=marja@chromium.org
> 
> Bug: v8:6425
> Change-Id: I05c21ca5e018da9c432c6bc963c7a96799336d1c
> Reviewed-on: https://chromium-review.googlesource.com/562879
> Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#46484}

TBR=marja@chromium.org,jgruber@chromium.org
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng

Bug: v8:6425
Change-Id: I5eba5fe43ad31c5c781ffcc8c604cd9c98baa57e
Reviewed-on: https://chromium-review.googlesource.com/565907
Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46542}
2017-07-10 22:17:58 +00:00
Michael Achenbach
ed8df4dd4c Revert "(Reland) [parser] moved load property position after dot"
This reverts commit 5b44ba0e34.

Reason for revert: Layout tests:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/16841

Original change's description:
> (Reland) [parser] moved load property position after dot
> 
> Currently LdaNamedProperty bytecode for expressions like a.b has position before dot. This CL moves this location after dot.
> It's important for later removing of Nop bytecodes in expressions like a.b() where a is local variable, property call and property load should have the same position.
> 
> R=​jgruber@chromium.org
> TBR=marja@chromium.org
> 
> Bug: v8:6425
> Change-Id: I05c21ca5e018da9c432c6bc963c7a96799336d1c
> Reviewed-on: https://chromium-review.googlesource.com/562879
> Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#46484}

TBR=kozyatinskiy@chromium.org,jgruber@chromium.org

Change-Id: If9d5fa5f46ed10a407559e9cf10d2a6a54dbe163
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:6425
Reviewed-on: https://chromium-review.googlesource.com/564418
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46491}
2017-07-08 11:37:12 +00:00
Alexey Kozyatinskiy
5b44ba0e34 (Reland) [parser] moved load property position after dot
Currently LdaNamedProperty bytecode for expressions like a.b has position before dot. This CL moves this location after dot.
It's important for later removing of Nop bytecodes in expressions like a.b() where a is local variable, property call and property load should have the same position.

R=jgruber@chromium.org
TBR=marja@chromium.org

Bug: v8:6425
Change-Id: I05c21ca5e018da9c432c6bc963c7a96799336d1c
Reviewed-on: https://chromium-review.googlesource.com/562879
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46484}
2017-07-07 14:57:10 +00:00
Leszek Swirski
a2fcdc7cc8 [runtime] Move profiler ticks from SFI to feedback vector
Instead of counting profiler ticks on the shared function info (which is
shared between native contexts), count them on the feedback vector
(which is not). This allows us to continue pushing optimization
decisions off the SFI, onto the feedback vector.

Note that a side-effect of this is that ICs don't have to walk the stack
to reset profiler ticks, as they can access the feedback vector directly
from their feedback nexus.

Change-Id: I232ae9e759fca75cd89d393148a4ff42caa2646f
Reviewed-on: https://chromium-review.googlesource.com/544888
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46411}
2017-07-05 12:04:50 +00:00
Michael Achenbach
4441809338 Revert "[parser] moved load property position after dot"
This reverts commit 217d654c9b.

Reason for revert: Changes layout tests:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/16520

Original change's description:
> [parser] moved load property position after dot
> 
> Currently LdaNamedProperty bytecode for expressions like a.b has position before dot. This CL moves this location after dot.
> It's important for later removing of Nop bytecodes in expressions like a.b() where a is local variable, property call and property load should have the same position.
> 
> R=​jgruber@chromium.org
> 
> Bug: v8:6425
> Change-Id: I528c5007de52215beba80851ab04693ecec038e2
> Reviewed-on: https://chromium-review.googlesource.com/543047
> Reviewed-by: Marja Hölttä <marja@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#46163}

TBR=marja@chromium.org,kozyatinskiy@chromium.org,jgruber@chromium.org

Change-Id: I94543526f39f0a20452fbce1a7bc6744cac66621
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:6425
Reviewed-on: https://chromium-review.googlesource.com/544993
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46171}
2017-06-23 12:46:57 +00:00
Alexey Kozyatinskiy
217d654c9b [parser] moved load property position after dot
Currently LdaNamedProperty bytecode for expressions like a.b has position before dot. This CL moves this location after dot.
It's important for later removing of Nop bytecodes in expressions like a.b() where a is local variable, property call and property load should have the same position.

R=jgruber@chromium.org

Bug: v8:6425
Change-Id: I528c5007de52215beba80851ab04693ecec038e2
Reviewed-on: https://chromium-review.googlesource.com/543047
Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46163}
2017-06-23 11:05:49 +00:00
Ross McIlroy
11a211ff1b Reland: [TypeFeedbackVector] Store optimized code in the vector
Since the feedback vector is itself a native context structure, why
not store optimized code for a function in there rather than in
a map from native context to code? This allows us to get rid of
the optimized code map in the SharedFunctionInfo, saving a pointer,
and making lookup of any optimized code quicker.

Original patch by Michael Stanton <mvstanton@chromium.org>

BUG=v8:6246,chromium:718891
TBR=yangguo@chromium.org,ulan@chromium.org

Change-Id: I3bb9ec0cfff32e667cca0e1403f964f33a6958a6
Reviewed-on: https://chromium-review.googlesource.com/500134
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45234}
2017-05-10 15:04:35 +00:00
Ross McIlroy
fd749344bf Revert "Reland: [TypeFeedbackVector] Store optimized code in the vector"
This reverts commit 662aa425ba.

Reason for revert: Crashing on Canary
BUG=chromium:718891

Original change's description:
> Reland: [TypeFeedbackVector] Store optimized code in the vector
> 
> Since the feedback vector is itself a native context structure, why
> not store optimized code for a function in there rather than in
> a map from native context to code? This allows us to get rid of
> the optimized code map in the SharedFunctionInfo, saving a pointer,
> and making lookup of any optimized code quicker.
> 
> Original patch by Michael Stanton <mvstanton@chromium.org>
> 
> BUG=v8:6246
> TBR=yangguo@chromium.org,ulan@chromium.org
> 
> Change-Id: Ic83e4011148164ef080c63215a0c77f1dfb7f327
> Reviewed-on: https://chromium-review.googlesource.com/494487
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#45084}

TBR=ulan@chromium.org,rmcilroy@chromium.org,yangguo@chromium.org,jarin@chromium.org
# Not skipping CQ checks because original CL landed > 1 day ago.
BUG=v8:6246

Change-Id: Idab648d6fe260862c2a0e35366df19dcecf13a82
Reviewed-on: https://chromium-review.googlesource.com/498633
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45174}
2017-05-08 20:57:30 +00:00
Ross McIlroy
662aa425ba Reland: [TypeFeedbackVector] Store optimized code in the vector
Since the feedback vector is itself a native context structure, why
not store optimized code for a function in there rather than in
a map from native context to code? This allows us to get rid of
the optimized code map in the SharedFunctionInfo, saving a pointer,
and making lookup of any optimized code quicker.

Original patch by Michael Stanton <mvstanton@chromium.org>

BUG=v8:6246
TBR=yangguo@chromium.org,ulan@chromium.org

Change-Id: Ic83e4011148164ef080c63215a0c77f1dfb7f327
Reviewed-on: https://chromium-review.googlesource.com/494487
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45084}
2017-05-04 11:21:59 +00:00
Michael Achenbach
5fcf508e07 Revert "[TypeFeedbackVector] Store optimized code in the vector"
This reverts commit c5ad9c6d8e.

Reason for revert: Fails on gc stress:
https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20GC%20Stress%20-%20custom%20snapshot/builds/12661

Original change's description:
> [TypeFeedbackVector] Store optimized code in the vector
> 
> Since the feedback vector is itself a native context structure, why
> not store optimized code for a function in there rather than in
> a map from native context to code? This allows us to get rid of
> the optimized code map in the SharedFunctionInfo, saving a pointer,
> and making lookup of any optimized code quicker.
> 
> Original patch by Michael Stanton <mvstanton@chromium.org>
> 
> BUG=v8:6246
> 
> Change-Id: I60ff8c408c3001bc272b4b198c9cbaea2872a9e5
> Reviewed-on: https://chromium-review.googlesource.com/476891
> Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Michael Stanton <mvstanton@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#45022}

TBR=ulan@chromium.org,rmcilroy@chromium.org,yangguo@chromium.org,mvstanton@chromium.org,jarin@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:6246

Change-Id: I9cd5735b03898cae6ae7adea0f19d32fceb31619
Reviewed-on: https://chromium-review.googlesource.com/493287
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45027}
2017-05-02 11:51:01 +00:00
Ross McIlroy
c5ad9c6d8e [TypeFeedbackVector] Store optimized code in the vector
Since the feedback vector is itself a native context structure, why
not store optimized code for a function in there rather than in
a map from native context to code? This allows us to get rid of
the optimized code map in the SharedFunctionInfo, saving a pointer,
and making lookup of any optimized code quicker.

Original patch by Michael Stanton <mvstanton@chromium.org>

BUG=v8:6246

Change-Id: I60ff8c408c3001bc272b4b198c9cbaea2872a9e5
Reviewed-on: https://chromium-review.googlesource.com/476891
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45022}
2017-05-02 11:20:23 +00:00
cbruni
3f73fecb13 [runtime] Ensure slow properties for simple {__proto__:null} literals.
With this CL we reduce the difference between directly using a null prototype
in a literal or using Object.create(null).
- The EmitFastCloneShallowObject builtin now supports cloning slow
  object boilerplates.
- Unified behavior to find the matching Map and instantiating it for
  Object.create(null) and literals with a null prototype.
- Cleanup of literal type parameter of CompileTimeValue, now in sync with
  ObjectLiteral flags.

Review-Url: https://codereview.chromium.org/2445333002
Cr-Commit-Position: refs/heads/master@{#44941}
2017-04-27 14:48:32 +00:00
yangguo
7b4e4ab70f Do not use new struct type where unnecessary.
We can use TUPLE2 or TUPLE3 for structs that do not need special
handling by deoptimizer and compiler.

This frees up a few instance types, so that adding the next few
new structs will not cause ABI compatibility to break.

R=mstarzinger@chromium.org

Review-Url: https://codereview.chromium.org/2811183005
Cr-Commit-Position: refs/heads/master@{#44685}
2017-04-18 12:46:39 +00:00
mvstanton
93f05b64ae [TypeFeedbackVector] Combine the literals array and the feedback vector.
They have the same lifetime. It's a match!

Both structures are native context dependent and dealt with (creation,
clearing, gathering feedback) at the same time. By treating the spaces used
for literal boilerplates as feedback vector slots, we no longer have to keep
track of the materialized literal count elsewhere.

A follow-on CL removes even more parser infrastructure related to this count.

BUG=v8:5456

Review-Url: https://codereview.chromium.org/2655853010
Cr-Commit-Position: refs/heads/master@{#42771}
2017-01-30 12:31:35 +00:00
petermarshall
f9367847b0 [Turbofan] Implement call with spread bytecode in assembly code.
We can share almost all of the architecture-specific builtin code with super-call-with-spread.

Info to port-writers: The code in CheckSpreadAndPushToStack has changed slightly from what was in Generate_ConstructWithSpread, in that we take the length of the spreaded parameters from the JSArray rather than the FixedArray backing store.

BUG=v8:5511

Review-Url: https://codereview.chromium.org/2649143002
Cr-Commit-Position: refs/heads/master@{#42632}
2017-01-24 14:37:01 +00:00
petermarshall
96220730e6 [Ignition/turbo] Add a CallWithSpread bytecode.
Also, emit a NewWithSpread bytecode for CallNew AST nodes where possible, rather than desugaring in the parser.

BUG=v8:5511

Review-Url: https://codereview.chromium.org/2629363002
Cr-Original-Commit-Position: refs/heads/master@{#42455}
Committed: 4bae43471d
Review-Url: https://codereview.chromium.org/2629363002
Cr-Commit-Position: refs/heads/master@{#42590}
2017-01-23 09:03:35 +00:00
petermarshall
75b861210f Revert of [Ignition/turbo] Add a CallWithSpread bytecode. (patchset #10 id:170001 of https://codereview.chromium.org/2629363002/ )
Reason for revert:
Causes a few bugs caught by clusterfuzz.

Original issue's description:
> [Ignition/turbo] Add a CallWithSpread bytecode.
>
> Also, emit a NewWithSpread bytecode for CallNew AST nodes where possible, rather than desugaring in the parser.
>
> BUG=v8:5511
>
> Review-Url: https://codereview.chromium.org/2629363002
> Cr-Commit-Position: refs/heads/master@{#42455}
> Committed: 4bae43471d

TBR=bmeurer@chromium.org,rmcilroy@chromium.org,verwaest@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5511

Review-Url: https://codereview.chromium.org/2642843002
Cr-Commit-Position: refs/heads/master@{#42470}
2017-01-18 17:06:17 +00:00
petermarshall
4bae43471d [Ignition/turbo] Add a CallWithSpread bytecode.
Also, emit a NewWithSpread bytecode for CallNew AST nodes where possible, rather than desugaring in the parser.

BUG=v8:5511

Review-Url: https://codereview.chromium.org/2629363002
Cr-Commit-Position: refs/heads/master@{#42455}
2017-01-18 12:58:58 +00:00