The new flags are
- v8_enable_atomic_object_field_writes that makes field write operations
  relaxed atomic.
- v8_enable_atomic_marking_state that makes the marking state and the
  write-barrier thread-safe.

The motivation is that we want to disable atomic object fields while
keeping the marking states thread-safe. This allows us to increase
TSAN coverage for background compilation and streaming tasks while
keeping the write-barrier used by the tasks thread-safe.

Bug: v8:10988
Change-Id: I11d66954dda4bf36d24c5e6f14ee5bc7a0f86094
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2448467Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70329}

This reverts commit 3f4e9bbe, along
with the following dependent changes (reverted to make this a clean revert):
76ad3ab5 [identity-map] Change resize heuristic
77cc96aa [identity-map] Cache the calculated Hash
bee5b996 [serializer] Remove Deserializer::Initialize
c8f73f22 [serializer] Cache instance type in PostProcessNewObject
4e7c99ab [identity-map] Remove double-lookups in IdentityMap

Reason for revert: major crash spike on Canary (https://crbug.com/1135027)

Original change's description:
> Reland^3 "[serializer] Allocate during deserialization"
>
> This is a reland of c4a062a9
> which was a reland of 28a30c57
> which was a reland of 5d7a29c9
>
> Fixes TSAN errors from non-atomic writes in the deserializer. Now all
> writes are (relaxed) atomic.
>
> Original change's description:
> > Reland^2 "[serializer] Allocate during deserialization"
> >
> > This is a reland of 28a30c57
> > which was a reland of 5d7a29c9
> >
> > The crashes were from calling RegisterDeserializerFinished on a null
> > Isolate pointer, for a deserializer that was never initialised
> > (specifically, ReadOnlyDeserializer when ROHeap is shared).
> >
> > Original change's description:
> > > Reland "[serializer] Allocate during deserialization"
> > >
> > > This is a reland of 5d7a29c9
> > >
> > > This reland shuffles around the order of checks in Heap::AllocateRawWith
> > > to not check the new space addresses until it's known that this is a new
> > > space allocation. This fixes an UBSan failure during read-only space
> > > deserialization, which happens before the new space is initialized.
> > >
> > > It also fixes some issues discovered by --stress-snapshot, around
> > > serializing ThinStrings (which are now elided as part of serialization),
> > > handle counts (I bumped the maximum handle count in that check), and
> > > clearing map transitions (the map backpointer field needed a Smi
> > > uninitialized value check).
> > >
> > > Original change's description:
> > > > [serializer] Allocate during deserialization
> > > >
> > > > This patch removes the concept of reservations and a specialized
> > > > deserializer allocator, and instead makes the deserializer allocate
> > > > directly with the Heap's Allocate method.
> > > >
> > > > The major consequence of this is that the GC can now run during
> > > > deserialization, which means that:
> > > >
> > > >   a) Deserialized objects are visible to the GC, and
> > > >   b) Objects that the deserializer/deserialized objects point to can
> > > >      move.
> > > >
> > > > Point a) is mostly not a problem due to previous work in making
> > > > deserialized objects "GC valid", i.e. making sure that they have a valid
> > > > size before any subsequent allocation/safepoint. We now additionally
> > > > have to initialize the allocated space with a valid tagged value -- this
> > > > is a magic Smi value to keep "uninitialized" checks simple.
> > > >
> > > > Point b) is solved by Handlifying the deserializer. This involves
> > > > changing any vectors of objects into vectors of Handles, and any object
> > > > keyed map into an IdentityMap (we can't use Handles as keys because
> > > > the object's address is no longer a stable hash).
> > > >
> > > > Back-references can no longer be direct chunk offsets, so instead the
> > > > deserializer stores a Handle to each deserialized object, and the
> > > > backreference is an index into this handle array. This encoding could
> > > > be optimized in the future with e.g. a second pass over the serialized
> > > > array which emits a different bytecode for objects that are and aren't
> > > > back-referenced.
> > > >
> > > > Additionally, the slot-walk over objects to initialize them can no
> > > > longer use absolute slot offsets, as again an object may move and its
> > > > slot address would become invalid. Now, slots are walked as relative
> > > > offsets to a Handle to the object, or as absolute slots for the case of
> > > > root pointers. A concept of "slot accessor" is introduced to share the
> > > > code between these two modes, and writing the slot (including write
> > > > barriers) is abstracted into this accessor.
> > > >
> > > > Finally, the Code body walk is modified to deserialize all objects
> > > > referred to by RelocInfos before doing the RelocInfo walk itself. This
> > > > is because RelocInfoIterator uses raw pointers, so we cannot allocate
> > > > during a RelocInfo walk.
> > > >
> > > > As a drive-by, the VariableRawData bytecode is tweaked to use tagged
> > > > size rather than byte size -- the size is expected to be tagged-aligned
> > > > anyway, so now we get an extra few bits in the size encoding.
> > > >
> > > > Bug: chromium:1075999
> > > > Change-Id: I672c42f553f2669888cc5e35d692c1b8ece1845e
> > > > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2404451
> > > > Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> > > > Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> > > > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > > > Cr-Commit-Position: refs/heads/master@{#70229}
> > >
> > > Bug: chromium:1075999
> > > Change-Id: Ibc77cc48b3440b4a28b09746cfc47e50c340ce54
> > > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2440828
> > > Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> > > Auto-Submit: Leszek Swirski <leszeks@chromium.org>
> > > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > > Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> > > Cr-Commit-Position: refs/heads/master@{#70267}
> >
> > Tbr: jgruber@chromium.org,ulan@chromium.org
> > Bug: chromium:1075999
> > Change-Id: Iaa8dc54895866ada0e34a7c9e8fff9ae1cb13f2d
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2444991
> > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#70279}
>
> Tbr: jgruber@chromium.org,ulan@chromium.org
> Cq-Include-Trybots: luci.v8.try:v8_linux64_tsan_rel_ng,v8_linux64_tsan_no_cm_rel_ng,v8_linux64_tsan_isolates_rel_ng
> Bug: chromium:1075999
> Change-Id: I0b9b11644aebc4cc8b07c62a0f765b24e4d73d89
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2445872
> Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> Auto-Submit: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70288}

TBR=ulan@chromium.org,jgruber@chromium.org,leszeks@chromium.org,dinfuehr@chromium.org

Bug: chromium:1075999, chromium:1135027
Change-Id: I5d0d9e49c0302d94ff7291834f5f18e7a0839eb7
Cq-Include-Trybots: luci.v8.try:v8_linux64_tsan_rel_ng,v8_linux64_tsan_no_cm_rel_ng,v8_linux64_tsan_isolates_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2451030Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70328}

Due to the lane numbering difference between Intel and IBM machines,
we need to switch the input registers when doing a vector pack.

Change-Id: I40e1fdae308e5dcd67aafab2abf099d4be0bb1a2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2450832Reviewed-by: Junliang Yan <junyan@redhat.com>
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/master@{#70327}

This reverts commit 6e621f84.

Reason for revert: Suspicion of GC stress failures like https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20gc%20stress/30260

Original change's description:
> [heap] String::MakeThin can get away without NotifyObjectLayoutChange
>
> String::MakeThin doesn't need to invoke NotifyObjectLayoutChange because
> ThinString will only introduce tagged values and hence will not
> overwrite recorded slots with untagged values.
>
> Bug: v8:10315
> Change-Id: Iaff9c06cef763462eb57bf3debc5183ae8db6fa0
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2448792
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70321}

TBR=ulan@chromium.org,leszeks@chromium.org,dinfuehr@chromium.org

Change-Id: I11c12e25702eb816cf616593d817a6ee3f691188
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:10315
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2451029Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70326}

Currently, when accessing a field that doesn't have a constant offset,
Torque emits code to compute each preceding indexed field's length and
add them all together. This works, but such code can get super long if a
class has many indexed fields, and especially if the length expressions
of some indexed fields refer to other indexed fields. We'd like the
output of the new C++ backend to be short enough to go in inline headers
which will be included in many compilation units.

This change attempts to reorganize the code so that the computation of
each length expression can only be emitted exactly once. This only
shortens the generated C++ code; the resulting TurboFan output should be
identical. There are two main parts:
1. For each indexed field, we already generate a macro that can get a
   Slice referring to that field. Update these macros to not use the dot
   operator on that field. Using the dot operator on the predecessor
   field is allowed.
2. Update the dot operator for indexed fields to emit a call to the
   macro from step 1.

This sort of reverses the dependency added by the previous change
https://crrev.com/c/2429566 : rather than the slice macros depending on
the dot operator, this change makes the dot operator depend on the slice
macros.

The overall torque_generated directory shrinks by under 1% with this
change, but the runtime_macros.cc file (which should eventually become
inline headers) shrinks by 24%. More to the point, this change keeps
runtime_macros.cc from ballooning out of control when we add a
work-in-progress Torque definition for ScopeInfo
( https://crrev.com/c/2357758 ).

Bug: v8:7793
Change-Id: I989dda9c3666f1a49281fef03acb35baebb5b63a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2432070Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#70325}

Change the resizing behaviour on insert to match that of the hash map
in base. Specifically, resize when hitting 80% occupancy.

Locally, I measure a ~6% improvement in serialization time from this
change.

Change-Id: I3fe84de39b2337859fe75fa6b3848198b82071ae
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2448798
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70324}

Bug: chromium:1130844, v8:10973
Change-Id: I912f2cf6cedaf22dd50d456622880ea266b65dcd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2445509
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70323}

... so that they match the corresponding DECL_* macros.

Change-Id: Idb26901eeb1219945a1e701dd7c28a58ce978bf9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2449977Reviewed-by: Santiago Aboy Solanes <solanes@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Auto-Submit: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70322}

String::MakeThin doesn't need to invoke NotifyObjectLayoutChange because
ThinString will only introduce tagged values and hence will not
overwrite recorded slots with untagged values.

Bug: v8:10315
Change-Id: Iaff9c06cef763462eb57bf3debc5183ae8db6fa0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2448792Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70321}

Fuzzers are executed in their own process, so instead of resetting flags
after execution, we can just keep the flag values.
This CL introduces a shared function to enable all staged features,
without ever resetting the value. This fixes a data race.

R=ahaas@chromium.org

Bug: v8:10979
Change-Id: I82ea35b887841850edd8b394a3644cf8df1e3bf8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2449969
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70320}

In IdentityMap, explicitly pass the key's hash so that it can be cached
between Lookup and Insert.

Change-Id: Ib8a2d96cc399ae025f54c61c129dd4cd18d86c7e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2448795
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70319}

We used not to emit canonical indexes for arrays and structs into
WasmModule::signature_ids, which resulted in signature_ids not referring
to the correct type indices in a WasmModule.

Changes:
- Rename signature_ids to canonical_type_ids.
- Emit trivial canonical type ids for structs and arrays.
- Add a test to catch the existing bug.
- Improve DCHECKs for module type accessors.

Bug: v8:7748
Change-Id: I67ad58865e35b459b21db12557564b652035db75
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2444989
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70318}

This splits WeakObjects into explicit global and local worklists.
The latter are defined in WeakObjects::Local and are thread-local.

The main thread local worklist is stored in
MarkCompactCollector::local_weak_objects and exists during marking
similar to local_marking_worklists. Concurrent markers create their
own local worklists that are published at the end.

Change-Id: I093fdc580b4609ce83455b860b90a5099085beac
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2440607
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70317}

The test does not expect GC to happen while it is running

Bug: v8:10988
Change-Id: Idcd30bde4ae1a7c3386a5d8c4c46e46e839e0fe9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2449971Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70316}

When debugging WebAssembly, calls to evaluateOnCallFrame always return
undefined. This CL enables evaluateOnCallFrame for WebAssembly and
creates a proxy object that is injected into the evaluation context.

Bug: chromium:1127914
Change-Id: I3f5cff3be2c9de45c7b1f3f7ed4fc2e1cc545ac6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2429265
Commit-Queue: Philip Pfaffe <pfaffe@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70315}

These three wasm methods do not use the context, but were passed one:
 * WasmInt32ToHeapNumber
 * WasmFloat32ToNumber
 * WasmFloat64ToNumber

Bug: v8:6949, v8:10933
Change-Id: I55e4264f7e06f3fb8338df77d12132c938acfcff
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2445934Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70314}

This change adds a new code generator, which supports a subset of the
instructions supported by the existing CSAGenerator, and instead of
generating CSA it generates runtime C++ code. The new generator is used
to generate a set of Torque macros that return slices to indexed fields.
These new macros should be sufficient to eventually support
Torque-generated field accessors, BodyDescriptors, verifier functions,
and postmortem field inspection in debug_helper.

Bug: v8:7793
Change-Id: Ife2d25cfd55a08238c625a8b04aca3ff2a0f4c63
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2429566Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#70313}

If we're testing printing in UTC timezone, then we have to be careful to
also input the date in UTC, else local timezone will affect the test.

Fixed: chromium:1135116
Change-Id: I49981c263e7b1fa1492b4644c5d4846fd94e5613
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2448793
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70312}

This was not happening when there was no need to typecheck the entry.

Additional changes:
- Add tests with null table entries for typed and untyped function
  tables.
- Allow AddIndirectFunctionTable in wasm-run-utils to specify table
  type.
- Add possibility to define tables in test-gc.cc.
- Merge trapTableOutOfBounds with trapInvalidFunc.
- Use trapTableOutOfBounds in call_indirect as appropriate.
- Fix emission of table types in wasm-module-builder.cc.

Bug: v8:9495
Change-Id: I4a857ff4378e5a87dc0646d94b4c75635a43c55b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2442622Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70311}

Remove the separate Initialize method from Deserializer, opting instead
to pass around SnapshotData where appropriate and pass the isolate
directly into the Deserializer's constructor.

Change-Id: I0092fadd9c81f14b2ce75145fd81af37c3947c65
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2448466
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70310}

Make all writes to JSMember.val_ atomic and atomically check for
emptiness in Trace.

Bug: chromium:1056170
Change-Id: Ia7034b9318df081aa61c9b6664903dd4f73402a5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2431569Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70309}

This CL extracts weak object worklist related code into separate files
and uses a macro to specify all weak object worklists in a generic way.

The motivation of the refactoring is twofold:
1) We can now enforce that each weak object worklist is updated after
   Scavenge. (Forgetting to define the update function causes a link
   time error.)
2) The reduced boilerplate will be useful for transitioning to the
   new ::heap::base::Worklist.

Change-Id: Ic80a7ccca010c09370d6525f43d78de24192f8ea
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2442624Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70308}

As a drive-by, rename "sanity check" to "check" in sharedarraybuffer.

Bug: v8:6949, v8:10933
Change-Id: Ifa2eac381ed309a099b018de4033816ebe3d828d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2429410
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70307}

We can use tag dispatching to distinguish between the synchronized and
non-synchronized accessors. Also eliminated the need of adding explicit
"synchronized" in the name when using the macros.

As a note, we currently have one case of using both relaxed and
synchronized accessors (Map::instance_descriptors).

Cleaned up:
 * BytecodeArray::source_position_table
 * Code::code_data_container
 * Code::source_position_table
 * FunctionTemplateInfo::call_code
 * Map::instance_descriptors
 * Map::layout_descriptor
 * SharedFunctionInfo::function_data

Bug: v8:7790
Change-Id: I5a502f4b2df6addb6c45056e77061271012c7d90
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2424130
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70306}

Other WebAssembly tools like wabt and wasmparser ignore empty strings
for local variable and parameter names, and just generate their own
names for it. Update V8 to comply with this convention.

Bug: chromium:1134531
Change-Id: Ic724482d93398feaf6b0797eec5a55f8ca508ca5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2448457Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Kim-Anh Tran <kimanh@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70305}

Instead of loading the map from the feedback vector for monomorphic
access, this CL directly inlines the expected map constant as a static
check.

In case this static check fails, we call out to a builtin which performs
additional dynamic map checks.

There are several dynamic map checks performed by the builtin for various
cases such as:
(a) IC is monomorphic with a map that's different from the initial
static map that we checked, in which case we perform another dynamic
map check.
(b) IC is monomorphic but incoming map is a deprecated map in which case
we call out the runtime to migrate this incoming object to a new map and
then try to handle it.
(c) IC has now transitioned to polymorphic in which we use the old
dynamic polymorphic checks to validate the map and handler.

Bug: v8:10582, v8:9684
Change-Id: Id87265ed513e4aef87b8e66c826afbf10f50a1d0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2429034
Commit-Queue: Sathya Gunasekaran  <gsathya@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70304}

Codegen timing and cache ageing are two important parameters for NCI
performance. This adds runtime flags for them:

 --turbo-nci-cache-ageing (default: false)
 --turbo-nci-delayed-codegen (default: true)

Note the behavioral change of disabling ageing by default for now.

Bug: v8:8888
Change-Id: Id9611185566f5c4828ad48e58c42424833d3323b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2438456
Commit-Queue: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Auto-Submit: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70303}

The lower 32 bits of output FPURegister is undefined now, this CL
copies the input FPURegister's lower 32 bits to output FPURegister.

Change-Id: I10c078fafeddd5de207ced4f7c01f35d32999733
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2449153Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
Cr-Commit-Position: refs/heads/master@{#70302}

Rather than having repeated IsFoo checks in PostProcessNewObject, which
means repeated handle accesses, map word accesses, and map pointer
decompressions, cache the instance type once and check it with
InstanceTypeChecker.

This gives a measurable 2-3% improvement in deserialization time (in my
informal local measurements).

Bug: chromium:1075999
Change-Id: I3e11588ad5d1c6ee2bbf93b82fa52c66496a325c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2440578
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70301}

Remove the pattern of calling 'Find' followed by 'Set' for IdentityMap,
with a single 'FindOrInsert' that explicitly returns whether an existing
entry was found, or the entry was inserted. This replaces 'Get', which
would return either an initialised or uninitialised entry (and callers
would rely on default initialisation to check this).

Also replace 'Set' with 'Insert', which explicitly requires that the
element didn't exist before. This matches expectations where it was
used (where those weren't replaced wholesale with 'FindOrInsert'), and
makes the naming consistent with 'FindOrInsert'.

Change-Id: I8fb76f4ac14fb92b88474965aafb1ace5fb79145
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2443135
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70300}

Run variant stress_concurrent_allocation in debug mode and with TSAN.
Failing tests will close tree and block CQ.

Bug: v8:10315
Change-Id: I0ba2921a3718a08b88516f209364b52c8817c331
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2436343
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70299}

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/bfc3ca5..1cb6993

Rolling v8/tools/clang: https://chromium.googlesource.com/chromium/src/tools/clang/+log/ab5ac1c..f513a0b

TBR=machenbach@chromium.org,tmrts@chromium.org,v8-waterfall-sheriff@grotations.appspotmail.com

Change-Id: I744a353ec4c80ccee5b63df024002bc0e77aabc7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2448646Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Commit-Queue: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#70298}

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/0f7a5f7..bfc3ca5

Rolling v8/third_party/aemu-linux-x64: L4Yg7-xN6xRY3FEAIYBqj7hMnWwvvnPYTNQr_umZm-IC..FgthknmEoQugl3GqOyqz_RsAjIMmeLsa960mZcmhE9UC

TBR=machenbach@chromium.org,tmrts@chromium.org,v8-waterfall-sheriff@grotations.appspotmail.com

Change-Id: If6ba34b7cc1e8cd00b9b331265ebc82c55e0294c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2447962Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Commit-Queue: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#70297}

The build location is now universally in out/build after infra change:
https://crrev.com/c/2426643

TBR=mslekova@chromium.org

Bug: chromium:1132088
Change-Id: I0d8867ed58adec79ed66f5e4dac375827e2679e3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2448451Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70296}

Change-Id: Ib879c4b1d473faa80863373d98631dfd67cfde9c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2448449
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70295}

We used to have extra data in this but now it's just an indirection to
CodeEntryAndLineNumber so use that everywhere instead.

Change-Id: I6dcedabc1502bc1eed25c05e23f04b996b91bae7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2440829
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70294}

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/9cc0704..0f7a5f7

Rolling v8/third_party/aemu-linux-x64: UABC8VAzZj56bPNLe3ou7AIlBjwHbiXOu6R9f5RbZWcC..L4Yg7-xN6xRY3FEAIYBqj7hMnWwvvnPYTNQr_umZm-IC

Rolling v8/third_party/catapult: https://chromium.googlesource.com/catapult/+log/8c88c75..d82d30d

Rolling v8/third_party/depot_tools: https://chromium.googlesource.com/chromium/tools/depot_tools/+log/69e30b2..1407cfd

Rolling v8/tools/clang: https://chromium.googlesource.com/chromium/src/tools/clang/+log/921f371..ab5ac1c

TBR=machenbach@chromium.org,tmrts@chromium.org,v8-waterfall-sheriff@grotations.appspotmail.com

Change-Id: I0aa95680425f45b63f692c7cb0e166546f0222be
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2446854Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Commit-Queue: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#70293}

`vperm` indices are taken from the five least significant bits
of the input byte. We need to make sure bigger values
are saturated to 31 to make vperm select 0 as the output.

Change-Id: I74715e909e4a50dec23f5423e53254836fe0ff8e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2446553Reviewed-by: Junliang Yan <junyan@redhat.com>
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/master@{#70292}

R=zhin@chromium.org

Bug: chromium:1134324
Change-Id: Ica1f8c290ba496c7c24d8ec46f963f389ad9e8fa
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2445875Reviewed-by: Zhi An Ng <zhin@chromium.org>
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70291}

Remove a spurious assert probably introduced by a bad merge that
disallowed RO_SPACE sharing when pointer compression is enabled.

Change-Id: I8a59a242667252dcbb098e5be405ac67a4e01a3d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2445877
Auto-Submit: Dan Elphick <delphick@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70290}