This CL passes feedback from the element kind deopt points
in Array.push to the deoptimizer. If the deopt points are
triggered, further speculation on Array.push is disallowed.
Bug: v8:7127, v8:7204
Change-Id: Ie91dee598bd8b8797110c8f468406327226893a4
Reviewed-on: https://chromium-review.googlesource.com/831523
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50171}
Add feedback to GrowFastElements operator and thread it
through to the deoptimize node it the lowering. The CL
uses the feedback to allow Array.push to disable speculation
if the grow operation deopts.
Bug: v8:7127, v8:7204
Change-Id: Ib5850a93759b9194c0fc2f191f6adf5d49cb7f55
Reviewed-on: https://chromium-review.googlesource.com/827128
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50145}
This reverts commit 917b9cb9fc.
In this CL, we canonicalize the fixed array when allocating storage for
empty fixed array. During initialization, we also make sure that we do
not write to the empty fixed array. This is quite hacky, but it
seems to be the least intrusive change.
Bug: chromium:793863
Change-Id: I1449ebac7c1e390467566a759bf70e7e2fabda31
Reviewed-on: https://chromium-review.googlesource.com/827013
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50119}
Add support for disallowing speculation upon deoptimize from
a CheckBound node, and use this in the case of array builtins
in js-call-reducer to prevent deoptimization loops.
Bug: v8:7127
Change-Id: I04cf655b10178d2938d2f0ee6b336601fab6463b
Reviewed-on: https://chromium-review.googlesource.com/822195
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50097}
This disallows speculation after deoptimization from any of
Array.{forEach,map,filter,find} due to CheckMap fails. Such
CheckMap fails happen if the builtins' function argument
causes the map of the array to change. The js-call-lowering
refrains from optimizing builtins for which speculation was
disallowed.
Bug: v8:6898, v8:7127
Change-Id: Ied6696f8fb023ee404fb82e9d37bfb061f293854
Reviewed-on: https://chromium-review.googlesource.com/819354
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50069}
This relands commit e71b802279.
This can now back in as the fix for chromium:787301 had enough time to
be tested in Canary.
Original change's description:
> [deoptimizer] Staged materialization of objects.
>
> The existing object materialization in the deoptimizer has the following problems:
>
> - Objects do not necessarily verify during materialization (because during the
> depth first walk we might have inconsistent objects).
>
> - Stack can overflow (because we just materialize using recursive calls).
>
> - We generalize object fields.
>
>
> This CL re-implements the materialization algorithm to solve this problem. The
> new implementation creates the objects in two steps:
>
> 1. We allocate space for all the objects. In general, we allocate ByteArrays
> of the right size. For leaf objects that cannot participate in cycles,
> we build and initialize the materialized objects completely.
>
> For JS objects, we insert markers into the byte array at the positions
> where unboxed doubles are expected.
>
> 2. We initialize all the objects with the proper field values and change the
> map from the ByteArray map to the correct map. This requires some sync
> with the concurrent marker (Heap::NotifyObjectLayoutChange).
>
> When initializing the JS object fields, we make sure that we respect
> the unboxed double marker.
>
> Bug: chromium:770106, v8:3836
> Change-Id: I1ec466a9d19db9538df4ba915516d4c3ca825632
> Reviewed-on: https://chromium-review.googlesource.com/777559
> Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#49821}
Bug: chromium:770106, v8:3836
Change-Id: Ied6c4e0fbae52713e55ae6dc13794a7521dbb8a5
Reviewed-on: https://chromium-review.googlesource.com/817745
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49982}
We cannot remove a speculative operation when it's type relies on it to deopt.
Fix this by only relying on the lowering to remove operations.
Bug: chromium:786521
Change-Id: I2cf45e8d45b76cfeb06e6329f323cade74719124
Reviewed-on: https://chromium-review.googlesource.com/793043
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49882}
The proper fix would be to make TruncatingUseInfoFromRepresentation
respect tagged signed use representation, but requires extra work
to refine typing for all values that are stored into Smi fields.
Bug: chromium:791245
Change-Id: I83965bcc18a836d2c758a6a8b1477a4aa2c6133d
Reviewed-on: https://chromium-review.googlesource.com/808866
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49870}
Eventually, we want to fix this also for tagged pointers (tracking bug: https://crbug.com/v8/7162).
Bug: chromium:791245
Change-Id: I93d6deff36cedcc9a4665fab0abe6fffdae9b61b
Reviewed-on: https://chromium-review.googlesource.com/806457
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49850}
This reverts commit e71b802279.
Reason for revert: Need to have a back-mergeable fix.
Original change's description:
> [deoptimizer] Staged materialization of objects.
>
> The existing object materialization in the deoptimizer has the following problems:
>
> - Objects do not necessarily verify during materialization (because during the
> depth first walk we might have inconsistent objects).
>
> - Stack can overflow (because we just materialize using recursive calls).
>
> - We generalize object fields.
>
>
> This CL re-implements the materialization algorithm to solve this problem. The
> new implementation creates the objects in two steps:
>
> 1. We allocate space for all the objects. In general, we allocate ByteArrays
> of the right size. For leaf objects that cannot participate in cycles,
> we build and initialize the materialized objects completely.
>
> For JS objects, we insert markers into the byte array at the positions
> where unboxed doubles are expected.
>
> 2. We initialize all the objects with the proper field values and change the
> map from the ByteArray map to the correct map. This requires some sync
> with the concurrent marker (Heap::NotifyObjectLayoutChange).
>
> When initializing the JS object fields, we make sure that we respect
> the unboxed double marker.
>
> Bug: chromium:770106, v8:3836
> Change-Id: I1ec466a9d19db9538df4ba915516d4c3ca825632
> Reviewed-on: https://chromium-review.googlesource.com/777559
> Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#49821}
TBR=ulan@chromium.org,mstarzinger@chromium.org,jarin@chromium.org
Change-Id: I0657fb75330700dd7883c600dacb25676ebb47f9
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:770106, v8:3836
Reviewed-on: https://chromium-review.googlesource.com/806160
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49834}
The existing object materialization in the deoptimizer has the following problems:
- Objects do not necessarily verify during materialization (because during the
depth first walk we might have inconsistent objects).
- Stack can overflow (because we just materialize using recursive calls).
- We generalize object fields.
This CL re-implements the materialization algorithm to solve this problem. The
new implementation creates the objects in two steps:
1. We allocate space for all the objects. In general, we allocate ByteArrays
of the right size. For leaf objects that cannot participate in cycles,
we build and initialize the materialized objects completely.
For JS objects, we insert markers into the byte array at the positions
where unboxed doubles are expected.
2. We initialize all the objects with the proper field values and change the
map from the ByteArray map to the correct map. This requires some sync
with the concurrent marker (Heap::NotifyObjectLayoutChange).
When initializing the JS object fields, we make sure that we respect
the unboxed double marker.
Bug: chromium:770106, v8:3836
Change-Id: I1ec466a9d19db9538df4ba915516d4c3ca825632
Reviewed-on: https://chromium-review.googlesource.com/777559
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49821}
Finally address that long-standing TODO where ConsString allocation in
TurboFan would always go for the two byte map instead of choosing the
one byte map if the inputs are one byte strings.
Bug: v8:5269, v8:7109
Change-Id: Ibcfceaf499ceebef0ef928ebc5f204bcacf29bc0
Reviewed-on: https://chromium-review.googlesource.com/799700
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49744}
This addresses two TODOs in Ignition where the Construct and the
ConstructWithSpread bytecodes didn't collect JSBoundFunction
new.target feedback. This is fairly trivial to add now with the
existing machinery and the TurboFan side of this was already fixed
before, so we can leverage the new feedback.
Bug: v8:5267, v8:7109
Change-Id: Iae257836716c14f05f5d301326cbe8b2acaeb38b
Reviewed-on: https://chromium-review.googlesource.com/793048
Reviewed-by: Mythri Alle <mythria@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49712}
In TurboFan we can easily recognize calls to String.prototype.slice
where the start parameter is -1 and the end parameter is either
undefined or not present. These calls either return an empty string if
the input string is empty, or the last character of the input string
as a single character string. So we can just make use of the existing
StringCharAt operator.
This reduces the overhead of the String.prototype.slice calls from
optimized code in the chai test of the web-tooling-benchmark
significantly. We observe a 2-3% improvement on the test.
Bug: v8:6936, v8:7137
Change-Id: Iebe02667446880f5760e3e8c80f8b7cc712df663
Reviewed-on: https://chromium-review.googlesource.com/795726
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49704}
Properly handle known JSBoundFunction instances as targets to
JSConstruct by inlining the construction of the eventual target.
Also if the target is the result of a JSCreateBoundFunction call,
where we can also fold the construction and construct the bound
target function directly instead.
This addresses half of the TODO in the JSConstruct lowering in the
JSCallReducer where so far we didn't handle bound functions.
Bug: v8:5267, v8:7109
Change-Id: I022dc7d4fbbe2c9972472e78a6d64f51e3134c94
Reviewed-on: https://chromium-review.googlesource.com/792947
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49664}
This extends the typing rule for NumberTrunc to deal with general number
inputs properly, thus addressing a long-standing TODO. We also add test
cases to ensure that the typing rule gets the corner cases for NaN and
-0 right.
Bug: v8:5267, v8:7109
Change-Id: Iedc541a0f4619f37da37ea36940f92472034cdf2
Reviewed-on: https://chromium-review.googlesource.com/792932
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49652}
This extends the typing rule for NumberRound to deal with general number
inputs properly, thus addressing a long-standing TODO. We also add test
cases to ensure that the typing rule gets the corner cases for NaN and
-0 right.
Bug: v8:5267, v8:7109
Change-Id: Ia865ec1d6f8d96f20641bee96891740a9fc6e627
Reviewed-on: https://chromium-review.googlesource.com/792931
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49651}
This extends the typing rule for NumberCeil to deal with general number
inputs properly, thus addressing a long-standing TODO. We also add test
cases to ensure that the typing rule gets the corner cases for NaN and
-0 right.
Bug: v8:5267, v8:7109
Change-Id: I9154e47e58ad106791613db0030051f2a802a981
Reviewed-on: https://chromium-review.googlesource.com/792930
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49650}
The typer's ToNumber (and thus ToInteger etc.) returns type None when
the input type is BigInt, but we weren't quite ready for that in a few
places.
R=jarin@chromium.org
Bug: v8:7121
Change-Id: Ib12c726338f1ec3dfb9ba5cf54b00cc8d1351a89
Reviewed-on: https://chromium-review.googlesource.com/785130
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49604}
Reland of https://chromium-review.googlesource.com/c/v8/v8/+/727893
The crashes should be fixed by https://chromium-review.googlesource.com/c/v8/v8/+/763531
Original change's description:
> Revert "Reland^5 "[turbofan] eagerly prune None types and deadness from the graph""
>
> This reverts commit ac0661b358.
>
> Reason for revert: Clusterfuzz unhappy: chromium:783019 chromium:783035
>
> Original change's description:
> > Reland^5 "[turbofan] eagerly prune None types and deadness from the graph"
> >
> > This gives up on earlier attempts to interpret DeadValue as a signal of
> > unreachable code. This does not work because free-floating dead value
> > nodes, and even pure branch nodes that use them, can get scheduled so
> > early that they get reachable. Instead, we now eagerly remove branches
> > that use DeadValue in DeadCodeElimination and replace DeadValue inputs
> > to value phi nodes with dummy values.
> >
> > Reland of https://chromium-review.googlesource.com/715716
> >
> > Bug: chromium:741225 chromium:776256
> > Change-Id: I251efd507c967d4a8882ad8fd2fd96c4185781fe
> > Reviewed-on: https://chromium-review.googlesource.com/727893
> > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#49188}
>
> TBR=jarin@chromium.org,tebbi@chromium.org
>
> Bug: chromium:741225 chromium:776256 chromium:783019 chromium:783035
> Change-Id: I6a8fa3a08ce2824a858ae01817688e63ed1f442e
> Reviewed-on: https://chromium-review.googlesource.com/758770
> Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#49262}
TBR=jarin@chromium.org,tebbi@chromium.org
# Not skipping CQ checks because original CL landed > 1 day ago.
Bug: chromium:741225 chromium:776256 chromium:783019 chromium:783035
Change-Id: I6c02b4beb02997ec34015ed2f6791a93c70f5e36
Reviewed-on: https://chromium-review.googlesource.com/772150
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49429}
This reverts commit ac0661b358.
Reason for revert: Clusterfuzz unhappy: chromium:783019 chromium:783035
Original change's description:
> Reland^5 "[turbofan] eagerly prune None types and deadness from the graph"
>
> This gives up on earlier attempts to interpret DeadValue as a signal of
> unreachable code. This does not work because free-floating dead value
> nodes, and even pure branch nodes that use them, can get scheduled so
> early that they get reachable. Instead, we now eagerly remove branches
> that use DeadValue in DeadCodeElimination and replace DeadValue inputs
> to value phi nodes with dummy values.
>
> Reland of https://chromium-review.googlesource.com/715716
>
> Bug: chromium:741225 chromium:776256
> Change-Id: I251efd507c967d4a8882ad8fd2fd96c4185781fe
> Reviewed-on: https://chromium-review.googlesource.com/727893
> Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#49188}
TBR=jarin@chromium.org,tebbi@chromium.org
Bug: chromium:741225 chromium:776256 chromium:783019 chromium:783035
Change-Id: I6a8fa3a08ce2824a858ae01817688e63ed1f442e
Reviewed-on: https://chromium-review.googlesource.com/758770
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49262}
This gives up on earlier attempts to interpret DeadValue as a signal of
unreachable code. This does not work because free-floating dead value
nodes, and even pure branch nodes that use them, can get scheduled so
early that they get reachable. Instead, we now eagerly remove branches
that use DeadValue in DeadCodeElimination and replace DeadValue inputs
to value phi nodes with dummy values.
Reland of https://chromium-review.googlesource.com/715716
Bug: chromium:741225 chromium:776256
Change-Id: I251efd507c967d4a8882ad8fd2fd96c4185781fe
Reviewed-on: https://chromium-review.googlesource.com/727893
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49188}
This adds support to the KeyedLoadIC to ignore out of bounds accesses
for Strings and return undefined instead. We add a dedicated bit to the
Smi handler to encode the OOB state and have TurboFan generate appropriate
code for that case as well. This is mostly useful when programs
accidentially access past the length of a string, which was observed and
fixed for example in Babel recently, see
https://github.com/babel/babel/pull/6589
for details. The idea is to also extend this mechanism to Arrays and
maybe other receivers, as reading beyond the length is also often used
in jQuery and other popular libraries.
Note that this is considered a mitigation for a performance cliff and
not a general optimization of OOB accesses. These should still be
avoided and handled properly instead.
This seems to further improve the babel test on the web-tooling-benchmark
by around 1%, because the OOB access no longer turns the otherwise
MONOMORPHIC access into MEGAMORPHIC state.
Bug: v8:6936, v8:7014
Change-Id: I9df03304e056d7001a65da8e9621119f8e9bb55b
Reviewed-on: https://chromium-review.googlesource.com/744022
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49049}
Following up on adding n-ary nodes, this extends the parser and
interpreter to support n-ary logical operations.
Bug: v8:6964
Bug: chromium:731861
Change-Id: Ife2141c389b9abccd917ab2aaddf399c436ef777
Reviewed-on: https://chromium-review.googlesource.com/735497
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49029}
We now represent the SameValue operation explicitly in TurboFan and the
operation can thus participate in all kinds of optimizations. Especially
we get rid of the JSCall node in the general case, which blocks several
optimizations across the call. The general, baseline performance is now
always on par with StrictEqual.
Once the StrictEqual operator is also a simplified operator, we should
start unifying the type based optimizations in SimplifiedLowering.
In the micro-benchmark we go from
testStrictEqual: 1422 ms.
testObjectIs: 1520 ms.
testManualSameValue: 1759 ms.
to
testStrictEqual: 1426 ms.
testObjectIs: 1357 ms.
testManualSameValue: 1766 ms.
which gives the expected result.
Bug: v8:7007
Change-Id: I0de3ff6ff6209ab4c3edb69de6a16e387295a9c8
Reviewed-on: https://chromium-review.googlesource.com/741228
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48994}
Expressions of the form
a_0 + a_1 + a_2 + a_3 + ... + a_n
seem to be reasonably common for cases such as building templates.
However, parsing these expressions results in a n-deep expression tree:
...
/
+
/ \
+ a_2
/ \
a_0 a_1
Traversing this tree during compilation can cause a stack overflow when n is
large.
Instead, for left-associate operations such as add, we now build up an
n-ary node in the parse tree, of the form
n-ary +
/ | \
/ | ... \
a_0 a_1 a_n
The bytecode compiler can now iterate through the child expressions
rather than recursing.
This patch only supports arithmetic operations -- subsequent patches
will enable the same optimization for logical tests and comma
expressions.
Bug: v8:6964
Bug: chromium:724961
Bug: chromium:731861
Bug: chromium:752081
Bug: chromium:771653
Bug: chromium:777302
Change-Id: Ie97e4ce42506fe62a7bc4ffbdaa90a9f698352cb
Reviewed-on: https://chromium-review.googlesource.com/733120
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48920}
When TurboFan sees a call to Reflect.get with exactly two parameters,
we can lower that to a direct call to the GetPropertyStub, which is
certainly faster than the general C++ builtin. This gives a nice
7-8% improvement on the chai test in the web-tooling-benchmark.
The micro-benchmark on the issue goes from
reflectGetPresent: 461 ms.
reflectGetAbsent: 470 ms.
to
reflectGetPresent: 141 ms.
reflectGetAbsent: 245 ms.
which is an up to 3.2x improvement.
Bug: v8:5996, v8:6936, v8:6937
Change-Id: Ic439fccb13f1a2f84386bf9fc31b4283d101afc4
Reviewed-on: https://chromium-review.googlesource.com/732988
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48841}
This adds a new InstanceOfIC where the TestInstanceOf bytecode collects
constant feedback about the right-hand side of instanceof operators,
including both JSFunction and JSBoundFunction instances. TurboFan then
uses the feedback to optimize instanceof in places where the right-hand
side is not a known constant (known to TurboFan).
This addresses the odd performance cliff that we see with instanceof in
functions with multiple closures. It was discovered as one of the main
bottlenecks on the uglify-es test in the web-tooling-benchmark. The
uglify-es test (run in separation) is ~18% faster with this change.
On the micro-benchmark in the tracking bug we go from
instanceofSingleClosure_Const: 69 ms.
instanceofSingleClosure_Class: 246 ms.
instanceofMultiClosure: 246 ms.
instanceofParameter: 246 ms.
to
instanceofSingleClosure_Const: 70 ms.
instanceofSingleClosure_Class: 75 ms.
instanceofMultiClosure: 76 ms.
instanceofParameter: 73 ms.
boosting performance by roughly 3.6x and thus effectively removing the
performance cliff around instanceof.
Bug: v8:6936, v8:6971
Change-Id: Ib88dbb9eaef9cafa4a0e260fbbde73427a54046e
Reviewed-on: https://chromium-review.googlesource.com/730686
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48820}
This revert is manual, but almost completely automatic.
It was just blocked by a single-line irrelevant refactoring change.
This reverts commit 1cee0e012e.
Reason for revert: chromium:776256
Original change's description:
> Reland^4 "[turbofan] eagerly prune None types and deadness from the graph"
>
> This fixes https://bugs.chromium.org/p/chromium/issues/detail?id=773954.
> The issue was that in the EffectControlLinearizer, the effect input of an
> {Unreachable} node was not updated, leaving a {Checkpoint} behind.
>
> This is a reland of 4cf476458f
> Original change's description:
> > Reland^3 "[turbofan] eagerly prune None types and deadness from the graph"
> >
> > This fixes the issues
> > https://bugs.chromium.org/p/chromium/issues/detail?id=772873
> > and https://bugs.chromium.org/p/chromium/issues/detail?id=772872.
> >
> > One problem was that mutating an effect node into Unreachable confused
> > the LoadElimination sidetables, so I just always create a new node now.
> >
> > The other problem was that UpdateBlockControl() was executed after
> > UpdateEffectPhi() in the lazy case. This reverted the update to the Merge input.
> > So now I make sure that UpdateEffectPhi() is always executed last.
> >
> > This is a reland of 6ddb5e7da7
> > Original change's description:
> > > Reland^2 "[turbofan] eagerly prune None types and deadness from the graph"
> > >
> > > Now, the EffectControlLinearizer connects all occurrences of Unreachable to the
> > > graph end. This fixes issues with later phases running DeadCodeElimination and
> > > introducing new DeadValue nodes when processing uses of Unreachable.
> > >
> > > This is a reland of 3c4bc27f13
> > > Original change's description:
> > > > Reland "[turbofan] eagerly prune None types and deadness from the graph"
> > > >
> > > > This is a reland of e1cdda2512
> > > > Original change's description:
> > > > > [turbofan] eagerly prune None types and deadness from the graph
> > > > >
> > > > > In addition to using the {Dead} node to prune dead control nodes and nodes that
> > > > > depend on them, we introduce a {DeadValue} node representing an impossible value
> > > > > that can occur at any position in the graph. The extended {DeadCodeElimination}
> > > > > prunes {DeadValue} and its uses, inserting a crashing {Unreachable} node into
> > > > > the effect chain when possible. The remaining uses of {DeadValue} are handled
> > > > > in {EffectControlLinearizer}, where we always have access to the effect chain.
> > > > > In addition to explicitly introduced {DeadValue} nodes, we consider any value use
> > > > > of a node with type {None} as dead.
> > > > >
> > > > > Bug: chromium:741225
> > > > > Change-Id: Icc4b636d1d018c452ba1a2fa7cd3e00e522f1655
> > > > > Reviewed-on: https://chromium-review.googlesource.com/641250
> > > > > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> > > > > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> > > > > Cr-Commit-Position: refs/heads/master@{#48208}
> > > >
> > > > Bug: chromium:741225
> > > > Change-Id: I21316913dae02864f7a6d7c9269405a79f054138
> > > > Reviewed-on: https://chromium-review.googlesource.com/692034
> > > > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> > > > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> > > > Cr-Commit-Position: refs/heads/master@{#48232}
> > >
> > > Bug: chromium:741225
> > > Change-Id: I5702ec34856c075717162153adc765774453c45f
> > > Reviewed-on: https://chromium-review.googlesource.com/702264
> > > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> > > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> > > Cr-Commit-Position: refs/heads/master@{#48366}
> >
> > Bug: chromium:741225
> > Change-Id: I4054a694d2521c2e1f0c4a3ad0f3cf100b5c536f
> > Reviewed-on: https://chromium-review.googlesource.com/709214
> > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#48469}
>
> Bug: chromium:741225
> Change-Id: Id9d4f3a3ae36cb3e38f80edcdba88efa7922ca24
> Reviewed-on: https://chromium-review.googlesource.com/715716
> Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#48660}
TBR=jarin@chromium.org,tebbi@chromium.org,bmeurer@chromium.org
Bug: chromium:741225 chromium:776256
Change-Id: Iaf2af3cb6dea5fdece43297cb9d987e7decc726d
Reviewed-on: https://chromium-review.googlesource.com/727804
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48749}
This addresses the odd performance cliff, where the CallIC tracks known
JSFunction targets, but goes MEGAMORPHIC when it sees a JSBoundFunction
target. With this fix in place the micro-benchmark on the bug goes from
arrowCall: 82 ms.
boundCall: 234 ms.
to
arrowCall: 81 ms.
boundCall: 80 ms.
so Function#bind doesn't cause any additional overhead anymore.
Bug: v8:5267, v8:6962
Change-Id: Iaceaf89fd3e99e2afe2ae45e96a6813a3ef8b1d2
Reviewed-on: https://chromium-review.googlesource.com/727879
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48722}
So far the JSCallReducer was only able to unfold constant
JSBoundFunction targets for JSCall nodes, which is not the
common case. With the introduction of JSCreateBoundFunction
operator earlier, we can now also recognize calls to bound
functions where the bind happens earlier in the function,
i.e. as the example of
a.map(f.bind(self))
in https://twitter.com/BenLesh/status/920700003974123520, which
is a handy way to use Function#bind. So this transformation
takes a node like
JSCall(JSCreateBoundFunction(bound_target_function,
bound_this,
a1,...,aN),
receiver, p1,...,pM)
and turns that into
JSCall(bound_target_function, bound_this, a1,...,aN,p1,...,pM)
allowing TurboFan to further inline the bound_target_function
at this call site if that's also inlinable (i.e. it's a known
constant JSFunction or the result of a JSCreateClosure call).
This improves the micro-benchmark from
arrowCall: 55 ms.
boundCall: 221 ms.
arrowMap: 181 ms.
boundMap: 806 ms.
to
arrowCall: 71 ms.
boundCall: 76 ms.
arrowMap: 188 ms.
boundMap: 186 ms.
so that Function#bind in this case is as fast as using closures,
which is an up to 4.3x improvement in the Array#map example.
Bug: v8:5257, v8:6961
Change-Id: Ibca650faad912bf9db1db6fbc48772e7551289a6
Reviewed-on: https://chromium-review.googlesource.com/727799
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48713}
This fixes https://bugs.chromium.org/p/chromium/issues/detail?id=773954.
The issue was that in the EffectControlLinearizer, the effect input of an
{Unreachable} node was not updated, leaving a {Checkpoint} behind.
This is a reland of 4cf476458f
Original change's description:
> Reland^3 "[turbofan] eagerly prune None types and deadness from the graph"
>
> This fixes the issues
> https://bugs.chromium.org/p/chromium/issues/detail?id=772873
> and https://bugs.chromium.org/p/chromium/issues/detail?id=772872.
>
> One problem was that mutating an effect node into Unreachable confused
> the LoadElimination sidetables, so I just always create a new node now.
>
> The other problem was that UpdateBlockControl() was executed after
> UpdateEffectPhi() in the lazy case. This reverted the update to the Merge input.
> So now I make sure that UpdateEffectPhi() is always executed last.
>
> This is a reland of 6ddb5e7da7
> Original change's description:
> > Reland^2 "[turbofan] eagerly prune None types and deadness from the graph"
> >
> > Now, the EffectControlLinearizer connects all occurrences of Unreachable to the
> > graph end. This fixes issues with later phases running DeadCodeElimination and
> > introducing new DeadValue nodes when processing uses of Unreachable.
> >
> > This is a reland of 3c4bc27f13
> > Original change's description:
> > > Reland "[turbofan] eagerly prune None types and deadness from the graph"
> > >
> > > This is a reland of e1cdda2512
> > > Original change's description:
> > > > [turbofan] eagerly prune None types and deadness from the graph
> > > >
> > > > In addition to using the {Dead} node to prune dead control nodes and nodes that
> > > > depend on them, we introduce a {DeadValue} node representing an impossible value
> > > > that can occur at any position in the graph. The extended {DeadCodeElimination}
> > > > prunes {DeadValue} and its uses, inserting a crashing {Unreachable} node into
> > > > the effect chain when possible. The remaining uses of {DeadValue} are handled
> > > > in {EffectControlLinearizer}, where we always have access to the effect chain.
> > > > In addition to explicitly introduced {DeadValue} nodes, we consider any value use
> > > > of a node with type {None} as dead.
> > > >
> > > > Bug: chromium:741225
> > > > Change-Id: Icc4b636d1d018c452ba1a2fa7cd3e00e522f1655
> > > > Reviewed-on: https://chromium-review.googlesource.com/641250
> > > > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> > > > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> > > > Cr-Commit-Position: refs/heads/master@{#48208}
> > >
> > > Bug: chromium:741225
> > > Change-Id: I21316913dae02864f7a6d7c9269405a79f054138
> > > Reviewed-on: https://chromium-review.googlesource.com/692034
> > > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> > > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> > > Cr-Commit-Position: refs/heads/master@{#48232}
> >
> > Bug: chromium:741225
> > Change-Id: I5702ec34856c075717162153adc765774453c45f
> > Reviewed-on: https://chromium-review.googlesource.com/702264
> > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#48366}
>
> Bug: chromium:741225
> Change-Id: I4054a694d2521c2e1f0c4a3ad0f3cf100b5c536f
> Reviewed-on: https://chromium-review.googlesource.com/709214
> Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#48469}
Bug: chromium:741225
Change-Id: Id9d4f3a3ae36cb3e38f80edcdba88efa7922ca24
Reviewed-on: https://chromium-review.googlesource.com/715716
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48660}
Ensure we only lower SpeculativeNumberBinops to a pure operator for
non-string plain primitives. Previously we could lower if a value might be
the-hole, however this would fail a CHECK in ConvertInputsToNumber which
expects a plain primitive.
BUG=chromium:772420
Change-Id: I0c755d10db7afd9cabfb638eca5662d70dfc8d51
Reviewed-on: https://chromium-review.googlesource.com/715717
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48649}
OSR for functions which use arguments no longer needs to be disabled, since
TurboFan handles the case.
Bug:
Change-Id: I121f1190a142c18f113bd5f875e258812645c43f
Reviewed-on: https://chromium-review.googlesource.com/721661
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48631}
Port the baseline version of Reflect.has to the CodeStubAssembler and
reuse the existing logic for HasProperty (i.e. the HasProperty builtin).
Also inline the Reflect.has builtin into TurboFan, by adding a check
on the target in front of a use of the JSHasProperty operator.
Technically this additional check is not necessary, because the
JSHasProperty operator already throws if the target is not a JSReceiver,
but the exception message is confusing then.
This improves the performance of the micro-benchmark from
reflectHasPresent: 337 ms.
reflectHasAbsent: 472 ms.
to
reflectHasPresent: 121 ms.
reflectHasAbsent: 216 ms.
which is a nice 2.8x improvement in the best case. It also improves the
chai test on the web-tooling-benchmark by around 1-2%, which is roughly
the expected win (since Reflect.has overall accounts for around 3-4%).
Bug: v8:5996, v8:6936, v8:6937
Change-Id: I856183229677a71c19936f06f2a4fc7a794a9a4a
Reviewed-on: https://chromium-review.googlesource.com/720959
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48608}
This reverts commit 4cf476458f.
Reason for revert: Broken effect chains detected by Clusterfuzz. Playing it safe for the 63 branch.
Original change's description:
> Reland^3 "[turbofan] eagerly prune None types and deadness from the graph"
>
> This fixes the issues
> https://bugs.chromium.org/p/chromium/issues/detail?id=772873
> and https://bugs.chromium.org/p/chromium/issues/detail?id=772872.
>
> One problem was that mutating an effect node into Unreachable confused
> the LoadElimination sidetables, so I just always create a new node now.
>
> The other problem was that UpdateBlockControl() was executed after
> UpdateEffectPhi() in the lazy case. This reverted the update to the Merge input.
> So now I make sure that UpdateEffectPhi() is always executed last.
>
> This is a reland of 6ddb5e7da7
> Original change's description:
> > Reland^2 "[turbofan] eagerly prune None types and deadness from the graph"
> >
> > Now, the EffectControlLinearizer connects all occurrences of Unreachable to the
> > graph end. This fixes issues with later phases running DeadCodeElimination and
> > introducing new DeadValue nodes when processing uses of Unreachable.
> >
> > This is a reland of 3c4bc27f13
> > Original change's description:
> > > Reland "[turbofan] eagerly prune None types and deadness from the graph"
> > >
> > > This is a reland of e1cdda2512
> > > Original change's description:
> > > > [turbofan] eagerly prune None types and deadness from the graph
> > > >
> > > > In addition to using the {Dead} node to prune dead control nodes and nodes that
> > > > depend on them, we introduce a {DeadValue} node representing an impossible value
> > > > that can occur at any position in the graph. The extended {DeadCodeElimination}
> > > > prunes {DeadValue} and its uses, inserting a crashing {Unreachable} node into
> > > > the effect chain when possible. The remaining uses of {DeadValue} are handled
> > > > in {EffectControlLinearizer}, where we always have access to the effect chain.
> > > > In addition to explicitly introduced {DeadValue} nodes, we consider any value use
> > > > of a node with type {None} as dead.
> > > >
> > > > Bug: chromium:741225
> > > > Change-Id: Icc4b636d1d018c452ba1a2fa7cd3e00e522f1655
> > > > Reviewed-on: https://chromium-review.googlesource.com/641250
> > > > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> > > > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> > > > Cr-Commit-Position: refs/heads/master@{#48208}
> > >
> > > Bug: chromium:741225
> > > Change-Id: I21316913dae02864f7a6d7c9269405a79f054138
> > > Reviewed-on: https://chromium-review.googlesource.com/692034
> > > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> > > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> > > Cr-Commit-Position: refs/heads/master@{#48232}
> >
> > Bug: chromium:741225
> > Change-Id: I5702ec34856c075717162153adc765774453c45f
> > Reviewed-on: https://chromium-review.googlesource.com/702264
> > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#48366}
>
> Bug: chromium:741225
> Change-Id: I4054a694d2521c2e1f0c4a3ad0f3cf100b5c536f
> Reviewed-on: https://chromium-review.googlesource.com/709214
> Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#48469}
TBR=jarin@chromium.org,tebbi@chromium.org
Change-Id: Icf6a6af4feaafd4bde28cb7b996735ff91bb3810
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:741225
Reviewed-on: https://chromium-review.googlesource.com/715096
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48482}
This fixes the issues
https://bugs.chromium.org/p/chromium/issues/detail?id=772873
and https://bugs.chromium.org/p/chromium/issues/detail?id=772872.
One problem was that mutating an effect node into Unreachable confused
the LoadElimination sidetables, so I just always create a new node now.
The other problem was that UpdateBlockControl() was executed after
UpdateEffectPhi() in the lazy case. This reverted the update to the Merge input.
So now I make sure that UpdateEffectPhi() is always executed last.
This is a reland of 6ddb5e7da7
Original change's description:
> Reland^2 "[turbofan] eagerly prune None types and deadness from the graph"
>
> Now, the EffectControlLinearizer connects all occurrences of Unreachable to the
> graph end. This fixes issues with later phases running DeadCodeElimination and
> introducing new DeadValue nodes when processing uses of Unreachable.
>
> This is a reland of 3c4bc27f13
> Original change's description:
> > Reland "[turbofan] eagerly prune None types and deadness from the graph"
> >
> > This is a reland of e1cdda2512
> > Original change's description:
> > > [turbofan] eagerly prune None types and deadness from the graph
> > >
> > > In addition to using the {Dead} node to prune dead control nodes and nodes that
> > > depend on them, we introduce a {DeadValue} node representing an impossible value
> > > that can occur at any position in the graph. The extended {DeadCodeElimination}
> > > prunes {DeadValue} and its uses, inserting a crashing {Unreachable} node into
> > > the effect chain when possible. The remaining uses of {DeadValue} are handled
> > > in {EffectControlLinearizer}, where we always have access to the effect chain.
> > > In addition to explicitly introduced {DeadValue} nodes, we consider any value use
> > > of a node with type {None} as dead.
> > >
> > > Bug: chromium:741225
> > > Change-Id: Icc4b636d1d018c452ba1a2fa7cd3e00e522f1655
> > > Reviewed-on: https://chromium-review.googlesource.com/641250
> > > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> > > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> > > Cr-Commit-Position: refs/heads/master@{#48208}
> >
> > Bug: chromium:741225
> > Change-Id: I21316913dae02864f7a6d7c9269405a79f054138
> > Reviewed-on: https://chromium-review.googlesource.com/692034
> > Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> > Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#48232}
>
> Bug: chromium:741225
> Change-Id: I5702ec34856c075717162153adc765774453c45f
> Reviewed-on: https://chromium-review.googlesource.com/702264
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#48366}
Bug: chromium:741225
Change-Id: I4054a694d2521c2e1f0c4a3ad0f3cf100b5c536f
Reviewed-on: https://chromium-review.googlesource.com/709214
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48469}
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/700254
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48275}
Until now keyed accesses to properties with string or symbol keys were
only optimized properly while the IC was monomorphic and would go
megamorphic as soon as there's another receiver map, even if the name
was still the same (i.e. the same symbol or internalized string). This
was a weird performance-cliff, that'll hurt modern code especially
because for symbols you can only access them via keyed loads and stores.
This CL fixes the state machine inside the ICs to properly transition to
POLYMORPHIC state (and stay there) as long as the new name matches the
previously recorded name. The FeedbackVector and TurboFan were already
able to deal with this and didn't need any updates.
On the micro-benchmark from the tracking bug we go from
testStringMonomorphic: 429 ms.
testSymbolMonomorphic: 431 ms.
testStringPolymorphic: 429 ms.
testSymbolPolymorphic: 5621 ms.
to
testStringMonomorphic: 429 ms.
testSymbolMonomorphic: 429 ms.
testStringPolymorphic: 429 ms.
testSymbolPolymorphic: 430 ms.
effectively eliminating the overhead for symbols completely, and
yielding a 13.5x performance boost.
This also seems to yield a 1% improvement on the ARES6 ML benchmark,
because it eliminates the KEYED_LOAD_ICs for the Symbol.species lookups.
Bug: v8:6367, v8:6278, v8:6344
Change-Id: I879fe56387b4c56203c1ad8ef8cafb6cc4c32897
Reviewed-on: https://chromium-review.googlesource.com/695108
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48261}
The TypedArray.prototype[Symbol.toStringTag] getter is currently the best (and
as far as I can tell only definitely side-effect free) way to check whether an
arbitrary object is a TypedArray - either generally TypedArray or a specific
one like Uint8Array. Using the getter is thus emerging as the general pattern
to detect TypedArrays, even Node.js now adapted it starting with
https://github.com/nodejs/node/pull/15663
for the isTypedArray and isUint8Array type checks in lib/internal/util/types.js
now.
The getter returns either the string with the TypedArray subclass name
(i.e. "Uint8Array") or undefined if the receiver is not a TypedArray.
This can be implemented with a simple elements kind dispatch, instead of
checking the instance type and then loading the class name from the
constructor, which requires a loop walking up the transition tree. This
CL ports the builtin to CSA and TurboFan, and changes the logic to a
simple elements kind check. On the micro-benchmark mentioned in the
referenced bug, the time goes from
testIsArrayBufferView: 565 ms.
testIsTypedArray: 2403 ms.
testIsUint8Array: 3847 ms.
to
testIsArrayBufferView: 566 ms.
testIsTypedArray: 965 ms.
testIsUint8Array: 965 ms.
which presents an up to 4x improvement.
Bug: v8:6874
Change-Id: I9c330b4529d9631df2f052acf023c6a4fae69611
Reviewed-on: https://chromium-review.googlesource.com/695021
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48254}
