Recent Fuchsia SDKs have begun removing both symbols for unsupported
POSIX APIs, and also the relevant definitions, and even headers.
This CL:
- Removes dependencies on <sys/resource.h>.
- Adds a working implementation of GetUserTime().
- Fixes GetCurrentThreadId() to use the native (32-bit) Fuchsia thread
handle, rather than the (64-bit) pthread*, to avoid potential for id
clashes when truncating the value into a 32-bit int.
Bug: chromium:707030
Change-Id: Ic5774e138f7657123dd65d0fb7ef5d87876766e8
Reviewed-on: https://chromium-review.googlesource.com/933247
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Commit-Queue: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51579}
This reverts commit 800daded0b.
Reason for revert: breaks arm64 build
Original change's description:
> [turbofan] Masking/poisoning in codegen (optimized code, arm64)
>
> This introduces masking of loads with speculation bit during code generation.
> At the moment, this is done only under the
> --branch-load-poisoning flag, and this CL enlarges the set of supported
> platforms from {x64, arm} to {x64, arm, arm64}.
>
> Overview of changes:
> - new register configuration configuration with one register reserved for
> the speculation poison/mask (kSpeculationPoisonRegister).
> - in codegen, we introduce an update to the poison register at the starts
> of all successors of branches (and deopts) that are marked as safety
> branches (deopts).
> - in memory optimizer, we lower all field and element loads to PoisonedLoads.
> - poisoned loads are then masked in codegen with the poison register.
> * only integer loads are masked at the moment.
>
> Bug: chromium:798964
> Change-Id: Ie6bc9c3bdac9998b0ef81f050a9c844399ca3ae4
> Reviewed-on: https://chromium-review.googlesource.com/928724
> Commit-Queue: Michael Stanton <mvstanton@chromium.org>
> Reviewed-by: Martyn Capewell <martyn.capewell@arm.com>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#51576}
TBR=rmcilroy@chromium.org,mvstanton@chromium.org,mstarzinger@chromium.org,jarin@chromium.org,rodolph.perfetta@arm.com,martyn.capewell@arm.com,pierre.langlois@arm.com
Change-Id: I1b5dad27f9620c7da3277602081f392de6221caf
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:798964
Reviewed-on: https://chromium-review.googlesource.com/937861
Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51578}
This reverts commit c41c7a0943.
Reason for revert: relanding now that the perf waterfall has had a stab at this revert.
Original change's description:
> Revert "Use all available workers for concurrent marking."
>
> This reverts commit 3c62f7ae07.
> (and commit 4939463c77)
>
> The goal of this revert is to contrast the effect on perf bots of
> landing it vs reverting it to more easily attribute its impact.
>
> R=hpayer@chromium.org
>
> Bug: chromium:812178
> Change-Id: I7c977b1b0b587f787263272400d87f6aae7af634
> Reviewed-on: https://chromium-review.googlesource.com/936761
> Commit-Queue: Hannes Payer <hpayer@chromium.org>
> Reviewed-by: Hannes Payer <hpayer@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#51546}
TBR=gab@chromium.org,hpayer@chromium.org
Change-Id: I1ecfc70867dc5424cba1a9ecd229ae031c3e9aa4
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:812178
Reviewed-on: https://chromium-review.googlesource.com/937725
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Commit-Queue: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51577}
This introduces masking of loads with speculation bit during code generation.
At the moment, this is done only under the
--branch-load-poisoning flag, and this CL enlarges the set of supported
platforms from {x64, arm} to {x64, arm, arm64}.
Overview of changes:
- new register configuration configuration with one register reserved for
the speculation poison/mask (kSpeculationPoisonRegister).
- in codegen, we introduce an update to the poison register at the starts
of all successors of branches (and deopts) that are marked as safety
branches (deopts).
- in memory optimizer, we lower all field and element loads to PoisonedLoads.
- poisoned loads are then masked in codegen with the poison register.
* only integer loads are masked at the moment.
Bug: chromium:798964
Change-Id: Ie6bc9c3bdac9998b0ef81f050a9c844399ca3ae4
Reviewed-on: https://chromium-review.googlesource.com/928724
Commit-Queue: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Martyn Capewell <martyn.capewell@arm.com>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51576}
Implement Load and Store instructions for liftoff on MIPS.
Function CallTrapCallbackForTesting also implemented to prevent
test from failing when address is out of range.
Bug: v8:6600
Change-Id: I85e48334d171ad6d86a02eeba51e4f07edaf9648
Reviewed-on: https://chromium-review.googlesource.com/934133
Commit-Queue: Sreten Kovacevic <sreten.kovacevic@mips.com>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Ivica Bogosavljevic <ivica.bogosavljevic@mips.com>
Cr-Commit-Position: refs/heads/master@{#51575}
Previously, Strings without an iterator would go to the runtime path
and fail on because it expected a JSReceiver type. This was in-line
with what the elements accessor expected. We can actually handle all
object types in the final slow path (using LookupIterator) so it is no
problem to change the accept types.
Bug: chromium:816289
Change-Id: Iebb8de0bb7551aee3894c8a23836d079c93726a7
Reviewed-on: https://chromium-review.googlesource.com/937461
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51574}
This is a reland of e7f9fb4a0d.
Original change's description:
> [Assembler][x64] Make Operand immutable
>
> This CL removes all setters from the Operand and removes the friendship
> relation between Assembler and Operand. All data fields of the Operand
> are set exactly once in the constructor, the Operand is immutable
> afterwards.
> In order to construct the data of an Operand easily, the OperandBuilder
> is introduced. After building an Operand, the data is copied to the
> const field of the Operand.
>
> R=mstarzinger@chromium.org
>
> Bug: v8:7310
> Change-Id: I1628052b8a0c47cbfbc3645dfdac5a0e9705977b
> Reviewed-on: https://chromium-review.googlesource.com/936741
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#51563}
Bug: v8:7310
Change-Id: I84df5e11b1811585fbba7309e3bb9c6b17e18c0b
Reviewed-on: https://chromium-review.googlesource.com/936628
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51573}
These helpers support off-heap code objects, for which they return
start, end, and size of the off-heap instruction stream.
Bug: v8:6666
Change-Id: Ib5e819d976eee3073b0354b8d8ce324b691f1b15
Reviewed-on: https://chromium-review.googlesource.com/937281
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51572}
Refactor EmitUnOp to be templatized in the type and the emit function,
similar to EmitBinOp. This simplified adding f32 and f64 unops.
R=ahaas@chromium.org
Bug: v8:6600
Change-Id: Iaab473a3bbcc45673ff6190d6b56244c48bfa5a6
Reviewed-on: https://chromium-review.googlesource.com/937201
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51568}
I loosened the DCHECKs here but I think they are still fundamentally
safe: `length` must be <= the actual length of the source (so that
there are actually enough elements to copy), and `length` must also be
<= the destination length, minus the offset (so there is enough space
to copy the elements into).
Bug: chromium:816317
Change-Id: Ice00ac60f4884363f6065ffee71f6ab1d1b32dbc
Reviewed-on: https://chromium-review.googlesource.com/937209
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51566}
This reverts commit e7f9fb4a0d.
Reason for revert: msvc compile error: https://build.chromium.org/p/client.v8/builders/V8%20Win64%20-%20msvc/builds/1573
Original change's description:
> [Assembler][x64] Make Operand immutable
>
> This CL removes all setters from the Operand and removes the friendship
> relation between Assembler and Operand. All data fields of the Operand
> are set exactly once in the constructor, the Operand is immutable
> afterwards.
> In order to construct the data of an Operand easily, the OperandBuilder
> is introduced. After building an Operand, the data is copied to the
> const field of the Operand.
>
> R=mstarzinger@chromium.org
>
> Bug: v8:7310
> Change-Id: I1628052b8a0c47cbfbc3645dfdac5a0e9705977b
> Reviewed-on: https://chromium-review.googlesource.com/936741
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#51563}
TBR=mstarzinger@chromium.org,clemensh@chromium.org
Change-Id: I8ae40de35e81765549f93ffe58f1b12286de6333
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7310
Reviewed-on: https://chromium-review.googlesource.com/936627
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51564}
This CL removes all setters from the Operand and removes the friendship
relation between Assembler and Operand. All data fields of the Operand
are set exactly once in the constructor, the Operand is immutable
afterwards.
In order to construct the data of an Operand easily, the OperandBuilder
is introduced. After building an Operand, the data is copied to the
const field of the Operand.
R=mstarzinger@chromium.org
Bug: v8:7310
Change-Id: I1628052b8a0c47cbfbc3645dfdac5a0e9705977b
Reviewed-on: https://chromium-review.googlesource.com/936741
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51563}
There's two considerations involving off-heap code and safepoint
tables.
1. Since the safepoint table is embedded within the instructions area
of code objects, we need to ensure that the actual instruction size
(i.e. safepoint_table_offset if a code object has safepoints) is
large enough for the off-heap trampoline.
2. The pc-relative calculation in SafepointTable::FindEntry must be
able to handle off-heap pcs.
Bug: v8:6666
Change-Id: I92a5ecc49d0a78755b89c3c5774523afb21cd724
Reviewed-on: https://chromium-review.googlesource.com/934242
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51561}
The key -> value edge is shown as "<index> / WeakMap", where <index> is
the index of the edge in the key.
Bug: chromium:778739, chromium:749502
Change-Id: I657051695f2a171372788dbb777543a55a35d554
Reviewed-on: https://chromium-review.googlesource.com/926524
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Alexei Filippov <alph@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51559}
This CL changes the builtin
StringSubstring(string, start, end)
to take start and end as untagged IntPtr values.
Bug: v8:7250, v8:7340
Change-Id: I39700d087da903f076a6ca163a8f880d31eea3a0
Reviewed-on: https://chromium-review.googlesource.com/923961
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51556}
The Operand class is small enough to be efficiently passed by value.
This saves binary size and performance because the Operand does not need
to be emitted to the caller's frame and loaded in the callee.
Binary saving is 37kB in release mode on ia32.
R=mstarzinger@chromium.org
Bug: v8:7310
Change-Id: Ibc103622ec216725c762c2ba4bb96451c99db556
Reviewed-on: https://chromium-review.googlesource.com/934264
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51555}
Snapshots don't yet work in 64-bit win/cross builds, so disable them
until they do.
No behavior change in builds that aren't 64-bit win/cross builds.
Bug: chromium:803591
Change-Id: I7a04c7e01a58a95a2bfb78c7d2593c7c5c5041cf
Reviewed-on: https://chromium-review.googlesource.com/936668
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51554}
This adds support for poisoning the stack pointer and implicit register
arguments like the context register and the function register in the
prologue of generated code with JavaScript linkage. The speculation
poison is computed similarly to the interpreter by matching expected
with actual code start addresses.
R=jarin@chromium.org,rmcilroy@chromium.org
BUG=chromium:798964
Change-Id: I5fa48844745459cf7b3d00c407a7b835f61c857b
Reviewed-on: https://chromium-review.googlesource.com/919167
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51553}
Currently we didn't always consistently use the String feedback on
JSAdd, but only if JSTypedLowering would already figure out statically
that one of the inputs is already a String. That leads to some odd
performance cliffs, as highlighted in the referenced bug.
This CL fixes the JSTypedLowering::ReduceJSAdd to always bake in the
String feedback. This improves the relevant performance tests from the
bug from
console.timeEnd: Runtime join3, 967.512000
console.timeEnd: Runtime join, 1004.599000
console.timeEnd: Runtime join3, 1124.764000
console.timeEnd: Runtime join, 966.164000
console.timeEnd: Runtime join3, 1145.296000
console.timeEnd: Runtime join, 966.176000
console.timeEnd: Runtime join3, 1145.272000
console.timeEnd: Runtime join, 931.266000
to
console.timeEnd: Runtime join3, 903.050000
console.timeEnd: Runtime join, 856.509000
console.timeEnd: Runtime join3, 945.144000
console.timeEnd: Runtime join, 840.038000
console.timeEnd: Runtime join3, 927.965000
console.timeEnd: Runtime join, 841.263000
console.timeEnd: Runtime join3, 929.342000
console.timeEnd: Runtime join, 858.143000
which corresponds to an 8-18% improvement.
Bug: v8:7415
Change-Id: I62e008298e4ee0864885b37817c91d055acf2a09
Reviewed-on: https://chromium-review.googlesource.com/936643
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51551}
Removing includes which are not needed and also not indirectly pulled in.
BUG=v8:7490, v8:7310
Change-Id: I219ba92c3281c3c245cc6c5574c85c2d51a217a9
Reviewed-on: https://chromium-review.googlesource.com/934722
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51550}
The CreateClosureMode introduced with 2ece046c5 is still not 100%
fail-safe and doesn't scale. What we really need instead, especially
when we might start removing the SharedFunctionInfo::code field
eventually, is to tell the JSCreateClosure node which code object to
use. So instead of adding magic around it, let's just pass it to the
node.
Bug: v8:2206, v8:7253, v8:7310
Change-Id: Iedb6ae468a763643617975f47d96854d1aeafbe9
Reviewed-on: https://chromium-review.googlesource.com/937121
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51548}
We use JSCreateClosure to also constructs closures for builtins, i.e.
for the callbacks created by the Promise constructor. For these builtins
we cannot set code to CompileLazy builtin, but need to use the code from
the SharedFunctionInfo. The explicit mode tells the lowering what it
should do (instead of relying on SharedFunctionInfo::native(), which is
not the right bit).
Bug: v8:2206, v8:7253, v8:7310
Change-Id: Ic956814e137c57b36ebb5d7b4d964dde5ee51a0d
Reviewed-on: https://chromium-review.googlesource.com/930964
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51547}
This reverts commit 3c62f7ae07.
(and commit 4939463c77)
The goal of this revert is to contrast the effect on perf bots of
landing it vs reverting it to more easily attribute its impact.
R=hpayer@chromium.org
Bug: chromium:812178
Change-Id: I7c977b1b0b587f787263272400d87f6aae7af634
Reviewed-on: https://chromium-review.googlesource.com/936761
Commit-Queue: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51546}
This implements the full set of f32 comparisons (f32.eq, f32.ne,
f32.lt, f32.gt, f32.le, f32.ge) on ia32 and x64.
R=titzer@chromium.org
Bug: v8:6600
Change-Id: I2be786431d01b4ed540b70f3e4a27c19b7d2649e
Reviewed-on: https://chromium-review.googlesource.com/928982
Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51545}
This is a follow-up to https://chromium-review.googlesource.com/904164
now that I've realized raw TRACE_EVENTs work in v8 (initially thought
had to go through heap()->tracer()).
After adding events to EvacuatePage(), the subitem event for evacuation tasks
became redundant. Since this results in a better output this CL applies
this approach to all paralell work items.
Not using TRACE_BACKGROUND_GC also avoids polluting logs with subitems
when using v8's tracing flags.
R=mlippautz@chromium.org
Bug: chromium:651354
Change-Id: I62efbde69da2a0a9bd255e34093d64924e339974
Reviewed-on: https://chromium-review.googlesource.com/934263
Commit-Queue: Gabriel Charette <gab@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51544}
I think those are safe to keep and add useful information to highlight
the type of evacuate copy step being performed.
This is a prerequisite for https://chromium-review.googlesource.com/c/v8/v8/+/934263
as it will drop tracing individual work items and will
leave it to top-level item trace events like these to
highlight individual work item's work.
Will reland after reverting them all however to confirm the re-adding
these doesn't cause regressions as the fine grain trace events
initially did.
R=hpayer@chromium.org
Bug: chromium:813824
Change-Id: I8e53b880ce0aeae08afa7a2c0f36a455f645bcfa
Reviewed-on: https://chromium-review.googlesource.com/934248
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Commit-Queue: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51543}
Change lowering for Store to use input replacement type.
Change-Id: Ic1fbbb37a3cc938fca7015d838933284bae6068e
Reviewed-on: https://chromium-review.googlesource.com/903266
Commit-Queue: Jing Bao <jing.bao@intel.com>
Reviewed-by: Aseem Garg <aseemgarg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51540}
Fuzzers after switching to ToT mjsunit.js, which accesses
Date.prototype, while for correctness fuzzing it's mocked out as a
proxy.
This makes the proxy return the property correctly.
TBR=yangguo@chromium.org
NOTRY=true
Bug: chromium:813833
Change-Id: Ic4b6412063f42c4e75905fbd568b7f81bc54daff
Reviewed-on: https://chromium-review.googlesource.com/936046
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51539}
This patch removes one unnecessary sub instruction in ComputeCodeStartAddress for SpeculationPoison generation at the beginning of each bytecode handler.
leaq rbx,[rip+0x0] => leaq rbx,[rip+0xfffffff9]
subq rbx,0x7 => To be removed
movq r9,0x0
cmpq rcx,rbx
movq rbx,0xffffffff
cmovzq r9,rbx
Change-Id: I7648ae27d4039488d1fc0f4c25477a5cb889bd6d
Reviewed-on: https://chromium-review.googlesource.com/933593
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Shiyu Zhang <shiyu.zhang@intel.com>
Cr-Commit-Position: refs/heads/master@{#51537}
Previously the API allowed the embedder to re fulfill a non pending
promise. This was changed as part of
c041296189.
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: I53dc028fecdcc6ab05c05cfc7795e89519ed9633
Reviewed-on: https://chromium-review.googlesource.com/932968
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51536}
`CodeStubAssembler::ToInteger_Inline` performs a `TaggedIsSmi` check,
and calls `ToInteger` with the appropriate truncation mode if the
input is not a Smi.
When we already know we’re dealing with something that’s not a Smi,
this check is redundant, and we can use
`CallBuiltin(Builtins::kToInteger*)` directly.
Bug: v8:7310
Change-Id: If538e39bcb738014bd03f10edd0051dac72b7ea3
Reviewed-on: https://chromium-review.googlesource.com/934901
Commit-Queue: Mathias Bynens <mathias@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51535}
Since we only need to store 18 different function kinds,
the bitfield approach was wasting space (requiring 11 bits).
This patch replaces the bitfield with a regular enum, and
updates all the FunctionKind predicates to use comparisons
instead of bitwise ops.
For the small amount of builtin code that depended upon being
able to do masking to determine whether something is a class
constructor, we still store two extra bits on FunctionKind,
which are computed when the SFI is initialized.
If this approach causes performance regressions (i.e., if it
turns out that other code was implicitly depending on masking
for fast checks), we can revert this or address it in
other ways (e.g., by doing similar caching of repeated checks
in the caller).
This is a reland of 42667bab5b.
Bug: v8:7310
Change-Id: I2ec54289ea687399c61d75b7aff2d849861a64f2
Reviewed-on: https://chromium-review.googlesource.com/934864
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51534}
