Commit Graph

28 Commits

Author SHA1 Message Date
Camillo Bruni
8ab75a56a2 [runtime] Rename Builtins::Name to Builtin 1/2
- Add new Builtin enum
- Move Builtins::Name:kXXX to Builtin::kXXX
- Update existing code

Follow CLs will unify the mix of using int builtin-ids and
Builtins::Name to only use the new Builtin enum and changing it to
an enum class.

Change-Id: Ib39aa45a25696acdf147f46392901b1e051deaa4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2905592
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74995}
2021-06-07 20:05:44 +00:00
Georg Neis
5a8f1efe7f Remove obsolete {Binary,Number}OperationHint::kSigned32
Change-Id: Ib1855adbf0292381f2b279d5b44fbddff551a4d5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2557499
Auto-Submit: Georg Neis <neis@chromium.org>
Commit-Queue: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71365}
2020-11-24 11:12:10 +00:00
Leszek Swirski
7281cb1d36 [compiler] Make is_compiled_scope take an explicit Isolate
This will allow it to take an OffThreadIsolate in the future, without
requiring GetIsolate on SharedFunctionInfo.

Change-Id: I7db56d5f0587585f829b26e60683c133760d8ff1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2282534
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68696}
2020-07-06 15:49:55 +00:00
Mythri A
a9b7830d3a Ensure bytecode isn't flushed when allocating feedback vector
This is a followup of the cl [1] that fixes a bug where bytecode was
getting flushed when allocating feedback vector. The fix added
IsCompiledScope before allocating a new feedback vector. We now pass
IsCompiledScope to JSFunction::EnsureFeedbackVector. This makes it
explicit that EnsureFeedbackVector expects a function that is compiled
and the bytecode shouldn't be flushed during the allocation.Also adds
a test.


[1] https://chromium-review.googlesource.com/c/v8/v8/+/2218066

Bug: v8:10560
Change-Id: I552c449a57555dffa625b2e4efa04c2c276fc0b4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2222347
Commit-Queue: Mythri Alle <mythria@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68142}
2020-06-03 13:50:17 +00:00
Georg Neis
53c1525df2 [turbofan] Distinguish two further modes of CheckBounds
Extend the flag parameter with a bit that decides if the input should
be converted (-0 to 0, and a string to the array index it represents).
Instruct redundancy elimination to never replace x with CheckBounds(x)
when this CheckBounds is of the converting kind.

Bug: chromium:1070892, chromium:1071743
Change-Id: I3125a6e267d56dae6bf6cb2f5f52d27ef65d7c79
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2157365
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67408}
2020-04-27 19:45:35 +00:00
Georg Neis
fd9e54a997 [turbofan] Preserve CheckBounds's kAbortOnOutOfBounds mode
A previous CL made the mode an explicit argument but failed to
keep SimplifiedLowering from overriding it.

Moreover, CheckedUint64Bounds so far didn't support the two modes.

Change-Id: I01d8bf90fca77940fbeb428da57608a59f812c75
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2124833
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66921}
2020-03-31 12:41:30 +00:00
Santiago Aboy Solanes
6e90f2f292 [ptr-compr] Remove Compressed mentions from in the pipeline
Including but not limiting to removing:
 * BitcastCompressedXXX
 * CheckedCompressedXXX
 * ChangeXXXToCompressedYYY
 * ChangeCompressedXXX

As a note, ChangeTaggedToCompressed can't be removed just yet as it
is still in use.

Bug: v8:7703
Change-Id: I98cf88a32adfa976d419e69702d1cac4d3e811a5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1903435
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64880}
2019-11-11 12:23:41 +00:00
Maya Lekova
156f187c53 Reland "[turbofan] Further brokerize BytecodeGraphBuilder"
This is a reland of 8ff8ddbaf5

Original change's description:
> [turbofan] Further brokerize BytecodeGraphBuilder
> 
> Replace all usages of VectorSlotPair with FeedbackSource.
> 
> Bug: v8:7790
> Change-Id: I0ac6e9cd8f5730154cc1842e267ca1ebfdebc874
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1763536
> Commit-Queue: Maya Lekova <mslekova@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#63378}

Bug: v8:7790
Change-Id: I54fbf4433a65681780fda4ded09ec2d145d36ec1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1768361
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63391}
2019-08-26 08:58:44 +00:00
Bill Budge
070cc9d141 Revert "[turbofan] Further brokerize BytecodeGraphBuilder"
This reverts commit 8ff8ddbaf5.

Reason for revert: Causes failures on GC Stress and TSan:

https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20gc%20stress/24138
https://ci.chromium.org/p/v8/builders/ci/V8%20Linux64%20TSAN/27969

Original change's description:
> [turbofan] Further brokerize BytecodeGraphBuilder
> 
> Replace all usages of VectorSlotPair with FeedbackSource.
> 
> Bug: v8:7790
> Change-Id: I0ac6e9cd8f5730154cc1842e267ca1ebfdebc874
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1763536
> Commit-Queue: Maya Lekova <mslekova@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#63378}

TBR=neis@chromium.org,mslekova@chromium.org

Change-Id: Ieb6fb24dd0626fd9eb2183844614ac5b3c8084e8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7790
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1769287
Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63387}
2019-08-23 17:55:00 +00:00
Maya Lekova
8ff8ddbaf5 [turbofan] Further brokerize BytecodeGraphBuilder
Replace all usages of VectorSlotPair with FeedbackSource.

Bug: v8:7790
Change-Id: I0ac6e9cd8f5730154cc1842e267ca1ebfdebc874
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1763536
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63378}
2019-08-23 16:04:01 +00:00
Santiago Aboy Solanes
d6b6565829 [ptr-compr] Add CheckedInt32ToCompressedSigned and use it
Also add tests for it.

Drive-by fix: Use ChangeInt32ToCompressedSmi since we have it

Cq-Include-Trybots: luci.v8.try:v8_linux64_pointer_compression_rel_ng
Cq-Include-Trybots: luci.v8.try:v8_linux64_arm64_pointer_compression_rel_ng
Bug: v8:7703
Change-Id: I45f04f8857acfc57b69eb4022a24ba082d28a91f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1708480
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62871}
2019-07-23 13:19:55 +00:00
Tobias Tebbi
4f48d04f97 [turbofan] introduce a deterministic tick measurement and assert optimization doesn't take too long
This adds a simple counter to Turbofan that's incremented throughout the compilation, hopefully
frequently enough so we can use it to detect divergence and performance bugs.
In addition, we assert that this counter never gets too high. That's the equivalent of a simple
timeout, just more deterministic. The limitations on Turbofan input size should guarantee that
we never exceed this limit. Since we probably do exceed it rarely, this check is only a DCHECK and
intended to detect performance and divergence issues, but not supposed to be performed in release
builds.

In addition, this CL adds UMA stats to observe the real world distribution of the tick measurement.

Bug: v8:9444

Change-Id: I182dac6ecac64715e3f5885ff5c7c17549351cd0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1695475
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62754}
2019-07-17 07:00:00 +00:00
Georg Neis
f434acc458 Revert recent ConsString-related changes
We see crashes in the wild that we suspect are caused by these changes.
This is a manual revert because of conflicts.

Revert "[turbofan] Fix incorrect CheckNonEmptyString lowering."
This reverts commit b3b7011867.

Revert "[turbofan] Fix incorrect lowering of CheckNonEmptyString."
This reverts commit 5758209026.

Revert "[turbofan] Significantly improve ConsString creation performance."
This reverts commit d6a60a0ee1.

Bug: v8:9147
Change-Id: I262c21e5406a9c4c8ad0e0f995582c5802f0fa1e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1571613
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60919}
2019-04-18 12:24:53 +00:00
Santiago Aboy Solanes
70b2216240 [Turbofan][ptr-compr] Add representation changes for and to Compressed* values
Includes both changing from compressed pointers and to compressed pointers.

Also added tests to the representation changer test

B

Cq-Include-Trybots: luci.v8.try:v8_linux64_pointer_compression_rel_ng,v8_linux64_arm64_pointer_compression_rel_ng
Bug: v8:8977
Change-Id: I8a13f6b7ec2208442aa354949173cc9061bce168
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1533866
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60587}
2019-04-03 09:45:53 +00:00
Mythri
7629afdb9d [lite] Allocate feedback vectors lazily
Allocate feedback vectors lazily when the function's interrupt budget has
reached a specified threshold. This cl introduces a new field in the
ClosureFeedbackCellArray to track the interrupt budget for allocating
feedback vectors. Using the interrupt budget on the bytecode array could
cause problems when there are closures across native contexts and we may
delay allocating feedback vectors in one of them causing unexpected
performance cliffs. In the long term we may want to remove interrupt budget
from bytecode array and use context specific budget for tiering up decisions
as well.

Bug: v8:8394
Change-Id: Ia8fbb71f5e8543a92f14c44aa762973da82d445c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1520719
Commit-Queue: Mythri Alle <mythria@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60450}
2019-03-25 16:02:38 +00:00
Benedikt Meurer
d6a60a0ee1 [turbofan] Significantly improve ConsString creation performance.
This change significantly improves the performance of string
concatenation in optimized code for the case where the resulting string
is represented as a ConsString. On the relevant test cases we go from

  serializeNaive: 10762 ms.
  serializeClever: 7813 ms.
  serializeConcat: 10271 ms.

to

  serializeNaive: 10278 ms.
  serializeClever: 5533 ms.
  serializeConcat: 10310 ms.

which represents a 30% improvement on the "clever" benchmark, which
tests specifically the ConsString creation performance.

This was accomplished via a couple of different steps, which are briefly
outlined here:

  1. The empty_string gets its own map, so that we can easily recognize
     and handle it appropriately in the TurboFan type system. This
     allows us to express (and assert) that the inputs to NewConsString
     are non-empty strings, making sure that TurboFan no longer creates
     "crippled ConsStrings" with empty left or right hand sides.
  2. Further split the existing String types in TurboFan to be able to
     distinguish between OneByte and TwoByte strings on the type system
     level. This allows us to avoid having to dynamically lookup the
     resulting ConsString map in case of ConsString creation (i.e. when
     we know that both input strings are OneByte strings or at least
     one of the input strings is TwoByte).
  3. We also introduced more finegrained feedback for the Add bytecode
     in the interpreter, having it collect feedback about ConsStrings,
     specifically ConsOneByteString and ConsTwoByteString. This feedback
     can be used by TurboFan to only inline the relevant code for what
     was seen so far. This allows us to remove the Octane/Splay specific
     magic in JSTypedLowering to detect ConsString creation, and instead
     purely rely on the feedback of what was seen so far (also making it
     possible to change the semantics of NewConsString to be a low-level
     operator, which is only introduced in SimplifiedLowering by looking
     at the input types of StringConcat).
  4. On top of the before mentioned type and interpreter changes we added
     new operators CheckNonEmptyString, CheckNonEmptyOneByteString, and
     CheckNonEmptyTwoByteString, which perform the appropriate (dynamic)
     checks.

There are several more improvements that are possible based on this, but
since the change was already quite big, we decided not to put everything
into the first change, but do some follow up tweaks to the type system,
and builtin optimizations later.

Tbr: mstarzinger@chromium.org
Bug: v8:8834, v8:8931, v8:8939, v8:8951
Change-Id: Ia24e17c6048bf2b04df966d3cd441f0edda05c93
Cq-Include-Trybots: luci.chromium.try:linux-blink-rel
Doc: https://bit.ly/fast-string-concatenation-in-javascript
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1499497
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60318}
2019-03-19 10:43:00 +00:00
Mythri
71c66873d6 [lite] Allocate FeedbackCell arrays for create closures in lite mode
We want to allocate feedback vectors lazily in lite mode. To do that,
we should create closures with the correct feedback cell. This cl
allocates feedback cell arrays to hold these feedback cells in lite mode.
This cl also modifies the compile lazy to builtin to expect these arrays
in the feedback cell.

Drive-by fix: InterpreterEntryTrampoline no longer has argument count in
a register. So updated comments and removed unnecessary push/pop of this
register.

Bug: v8:8394
Change-Id: I10d8ca67cebce61a284f0c80b200e1f0c24577a2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1511274
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60189}
2019-03-12 14:28:29 +00:00
Jaroslav Sevcik
7bb6dc0e06 [turbofan] Introduce aborting bounds checks.
Instead of eliminating bounds checks based on types, we introduce
an aborting bounds check that crashes rather than deopts.

Bug: v8:8806
Change-Id: Icbd9c4554b6ad20fe4135b8622590093679dac3f
Reviewed-on: https://chromium-review.googlesource.com/c/1460461
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59467}
2019-02-08 16:14:23 +00:00
Benedikt Meurer
15c31fe461 [turbofan] Add support for huge DataViews.
This introduces Word64 support for the CheckBounds operator, which now
lowers to either CheckedUint32Bounds or CheckedUint64Bounds after the
representation selection. The right hand side of CheckBounds can now
be any positive safe integer on 64-bit architectures, whereas it remains
Unsigned31 for 32-bit architectures. We only use the extended Word64
support when the right hand side is outside the Unsigned31 range, so
for everything except DataViews this means that the performance should
remain the same. The typing rule for the CheckBounds operator was
updated to reflect this new behavior.

The CheckBounds with a right hand side outside the Unsigned31 range will
pass a new Signed64 feedback kind, which is handled with newly introduced
CheckedFloat64ToInt64 and CheckedTaggedToInt64 operators in representation
selection.

The JSCallReducer lowering for DataView getType()/setType() methods was
updated to not smi-check the [[ByteLength]] and [[ByteOffset]] anymore,
but instead just use the raw uintptr_t values and operate on any value
(for 64-bit architectures these fields can hold any positive safe
integer, for 32-bit architectures it's limited to Unsigned31 range as
before). This means that V8 can now handle huge DataViews fully, without
falling off a performance cliff.

This refactoring even gave us some performance improvements, on a simple
micro-benchmark just exercising different DataView accesses we go from

  testDataViewGetUint8: 796 ms.
  testDataViewGetUint16: 997 ms.
  testDataViewGetInt32: 994 ms.
  testDataViewGetFloat64: 997 ms.

to

  testDataViewGetUint8: 895 ms.
  testDataViewGetUint16: 889 ms.
  testDataViewGetInt32: 888 ms.
  testDataViewGetFloat64: 890 ms.

meaning we lost around 10% on the single byte case, but gained 10% across
the board for all the other element sizes.

Design-Document: http://bit.ly/turbofan-word64
Bug: chromium:225811, v8:4153, v8:7881, v8:8171, v8:8383
Change-Id: Ic9d1bf152e47802c04dcfd679372e5c85e4abc83
Reviewed-on: https://chromium-review.googlesource.com/c/1303732
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57095}
2018-10-29 15:17:57 +00:00
Benedikt Meurer
f19c4a594f [turbofan] ReceiverOrNullOrUndefined feedback for JSEqual.
This changes the ReceiverOrOddball feedback on JSStrictEqual to
ReceiverOrNullOrUndefined feedback, which can also safely be
consumed by JSEqual (we cannot generally accept any oddball here
since booleans trigger implicit conversions, unfortunately).
Thus we replace the previously introduced CheckReceiverOrOddball
with CheckReceiverOrNullOrUndefined, and drop CheckOddball, since
we will no longer collect Oddball feedback separately.

TurboFan will then turn a JSEqual[ReceiverOrNullOrUndefined] into
a sequence like this:

```
left = CheckReceiverOrNullOrUndefined(left);
right = CheckReceiverOrNullOrUndefined(right);
result = if ObjectIsUndetectable(left) then
           ObjectIsUndetectable(right)
         else
           ReferenceEqual(left, right);
```

This significantly improves the peak performance of abstract equality
with Receiver, Null or Undefined inputs. On the test case outlined in
http://crbug.com/v8/8356 we go from

  naive: 2946 ms.
  tenary: 2134 ms.

to

  naive: 2230 ms.
  tenary: 2250 ms.

which corresponds to a 25% improvement on the abstract equality case.
For regular code this will probably yield more performance, since we
get rid of the JSEqual operator, which might have arbitrary side
effects and thus blocks all kinds of TurboFan optimizations. The
JSStrictEqual case is slightly slower now, since it has to rule out
booleans as well (even though that's not strictly necessary, but
consistency is key here).

This way developers can safely use `a == b` instead of doing a dance
like `a == null ? b == null : a === b` (which is what dart2js does
right now) when both `a` and `b` are known to be Receiver, Null or
Undefined. The abstract equality is not only faster to parse than
the tenary, but also generates a shorter bytecode sequence. In the
test case referenced in http://crbug.com/v8/8356 the bytecode for
`naive` is

```
StackCheck
Ldar a1
TestEqual a0, [0]
JumpIfFalse [5]
LdaSmi [1]
Return
LdaSmi [2]
Return
```

which is 14 bytes, whereas the `tenary` function generates

```
StackCheck
Ldar a0
TestUndetectable
JumpIfFalse [7]
Ldar a1
TestUndetectable
Jump [7]
Ldar a1
TestEqualStrict a0, [0]
JumpIfToBooleanFalse [5]
LdaSmi [1]
Return
LdaSmi [2]
Return
```

which is 24 bytes. So the `naive` version is 40% smaller and requires
fewer bytecode dispatches.

Bug: chromium:898455, v8:8356
Change-Id: If3961b2518b4438700706b3bd6071d546305e233
Reviewed-on: https://chromium-review.googlesource.com/c/1297315
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56948}
2018-10-24 13:45:22 +00:00
Benedikt Meurer
8f00d61dae [turbofan] Collect and consume (ReceiverOr)Oddball feedback for StrictEqual.
This CL introduces proper Oddball and ReceiverOrOddball states for the
CompareOperationFeedback, and updates the StrictEqual IC to collect this
feedback as well. Previously it would not collect Oddball feedback, not
even in the sense of NumberOrOddball, since that's not usable for the
SpeculativeNumberEqual.

The new feedback is handled via newly introduced CheckReceiverOrOddball
and CheckOddball operators in TurboFan, introduced by JSTypedLowering.
Just like with the Receiver feedback, it's enough to check one side and
do a ReferenceEqual afterwards, since strict equal can only yield true
if both sides refer to the same instance.

This improves the benchmark mentioned in http://crbug.com/v8/8356 from

  naive: 2950 ms.
  tenary: 2456 ms.

to around

  naive: 2996 ms.
  tenary: 2192 ms.

which corresponds to a roughly 10% improvement in the case for the
tenary pattern, which is currently used by dart2js. In real world
scenarios this will probably help even more, since TurboFan is able
to optimize across the strict equality, i.e. there's no longer a stub
call forcibly spilling all registers that are live across the call.

This new feedback will be used as a basis for the JSEqual support for
ReceiverOrOddball, which will allow dart2js switching to the shorter
a==b form, at the same peak performance.

Bug: v8:8356
Change-Id: Iafbf5d64fcc9312f9e575b54c32c631ce9b572b2
Reviewed-on: https://chromium-review.googlesource.com/c/1297309
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56925}
2018-10-24 04:37:14 +00:00
Georg Neis
be41df9646 [turbofan] Rename "js_heap_broker" to "broker".
There's no ambiguity and the shorter name makes things easier to read.

Bug: v8:7790
Change-Id: Ibcf3fd7f38a91e26a83cd335fad0ec80a5fe9be1
Reviewed-on: https://chromium-review.googlesource.com/c/1278392
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56623}
2018-10-15 08:17:17 +00:00
Benedikt Meurer
bcdede0c53 [turbofan] Eliminate redundant Smi checks around array accesses.
As identified in the web-tooling-benchmark, there are specific code
patterns involving array indexed property accesses and subsequent
comparisons of those indices that lead to repeated Smi checks in the
optimized code, which in turn leads to high register pressure and
generally bad register allocation. An example of this pattern is
code like this:

```js
function f(a, n) {
  const i = a[n];
  if (n >= 1) return i;
}
```

The `a[n]` property access introduces a CheckBounds on `n`, which
later lowers to a `CheckedTaggedToInt32[dont-check-minus-zero]`,
however the `n >= 1` comparison has collected `SignedSmall` feedback
and so it introduces a `CheckedTaggedToTaggedSigned` operation. This
second Smi check is redundant and cannot easily be combined with the
earlier tagged->int32 conversion, since that also deals with heap
numbers and even truncates -0 to 0.

So we teach the RedundancyElimination to look at the inputs of these
speculative number comparisons and if there's a leading bounds check
on either of these inputs, we change the input to the result of the
bounds check. This avoids the redundant Smi checks later and generally
allows the SimplifiedLowering to do a significantly better job on the
number comparisons. We only do this in case of SignedSmall feedback
and only for inputs that are not already known to be in UnsignedSmall
range, to avoid doing too many (unnecessary) expensive lookups during
RedundancyElimination.

All of this is safe despite the fact that CheckBounds truncates -0
to 0, since the regular number comparisons in JavaScript identify
0 and -0 (unlike Object.is()). This also adds appropriate tests,
especially for the interesting cases where -0 is used only after
the code was optimized.

Bug: v8:6936, v8:7094
Change-Id: Ie37114fb6192e941ae1a4f0bfe00e9c0a8305c07
Reviewed-on: https://chromium-review.googlesource.com/c/1246181
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56428}
2018-10-07 12:00:01 +00:00
Benedikt Meurer
248fd5ffe0 Revert "[turbofan] Do not consume SignedSmall feedback in TurboFan anymore."
This reverts commit 4fd92b252b.

Reason for revert: Significant tankage on the no-mitigations bots (bad timing on the regular bots)

Original change's description:
> [turbofan] Do not consume SignedSmall feedback in TurboFan anymore.
> 
> This changes TurboFan to treat SignedSmall feedback similar to Signed32
> feedback for binary and compare operations, in order to simplify and
> unify the machinery.
> 
> This is an experiment. If this turns out to tank performance, we will
> need to revisit and ideally revert this change.
> 
> Bug: v8:7094
> Change-Id: I885769c2fe93d8413e59838fbe844650c848c3f1
> Reviewed-on: https://chromium-review.googlesource.com/c/1261442
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#56411}

TBR=jarin@chromium.org,bmeurer@chromium.org

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

Bug: v8:7094
Change-Id: I9fff3b40e6dc0ceb7611b55e1ca9940089470404
Reviewed-on: https://chromium-review.googlesource.com/c/1267175
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56427}
2018-10-07 10:19:01 +00:00
Benedikt Meurer
4fd92b252b [turbofan] Do not consume SignedSmall feedback in TurboFan anymore.
This changes TurboFan to treat SignedSmall feedback similar to Signed32
feedback for binary and compare operations, in order to simplify and
unify the machinery.

This is an experiment. If this turns out to tank performance, we will
need to revisit and ideally revert this change.

Bug: v8:7094
Change-Id: I885769c2fe93d8413e59838fbe844650c848c3f1
Reviewed-on: https://chromium-review.googlesource.com/c/1261442
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56411}
2018-10-05 12:41:22 +00:00
Georg Neis
74b40e34d5 [turbofan] Remove redundant isolate argument from typers.
This is just a cleanup.

Bug: v8:7790
Change-Id: Ic0114451159b8c504f527f3cf3bdaed6a8cc8741
Reviewed-on: https://chromium-review.googlesource.com/1243103
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56206}
2018-09-25 13:00:05 +00:00
Benedikt Meurer
3a9466a89c [turbofan] Unify RedundancyElimination for speculative number operations.
Remove the NumberConstant right hand side limitation for the speculative
number operation optimization, and extend the logic to also deal with
SpeculativeToNumber, which is common when dealing with postfix increment
and array operations.

Also add appropriate tests for all the relevant cases, specifically we
mjsunit tests to increase the general coverage for the various cases
here (in addition to dedicated unittests).

Bug: v8:8015
Change-Id: I8c92f98490c63b07eb19686efd404322979e57c4
Reviewed-on: https://chromium-review.googlesource.com/1235919
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56072}
2018-09-20 12:08:55 +00:00
Benedikt Meurer
4491072507 [turbofan] Fix RedundancyElimination and add more test coverage.
Make the RedundancyElimination handle all simplified operators that are
listed in the SIMPLIFIED_CHECKED_OP_LIST, and fix a couple of bugs and
oversights in the code. This also adds a lot of test coverage for all
the cases that we care about in RedundancyElimination (with respect to
Check/Checked simplified operators).

Bug: v8:8015
Change-Id: I57d29113389841b09abcd013313bf5dd1c67735f
Reviewed-on: https://chromium-review.googlesource.com/1233655
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56032}
2018-09-19 13:08:12 +00:00