This CL changes SharedFunctionInfo::GetBytecodeArray to a function
template, which is specialized for Isolate and LocalIsolate arguments.
This allows main thread only uses to avoid taking a lock.

Bug: v8:7790, chromium:1154603
Change-Id: I3462c4e36b66073e09393c01c765dd8a018a98f0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2595307
Commit-Queue: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71833}

When dereferencing handles check whether the main thread is parked
similar to background threads.

Bug: chromium:1152995
Change-Id: Ic79680f1b1c49f5f0ad872d6377ca45920a18b98
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2575061Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Georg Neis (ooo until January 5) <neis@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71760}

Apart from removing Min and Max (utils.h), this is mostly a renaming.

In a few cases I had to add a cast. In a bunch of cases I had to use
initializer lists to force call-by-value for static member constants
because call-by-reference wouldn't compile (like in the previous CL).
In a few places I used initializer lists in place of nested min/max
operations.

Bug: v8:11074
Change-Id: I53a5411be6334ff41e7a8517e6b87fb46f14d086
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2545523
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71380}

Because of LocalHeap safepoints, our existing assert scopes don't
necessarily maintain the same guarantees as desired. In particular,
DisallowHeapAllocation no longer guarantees that objects don't move.

This patch transitions DisallowHeapAllocation to
DisallowGarbageCollection, to ensure that code using this scope is
also protected against safepoints.

Change-Id: I0411425884f6849982611205fb17bb072881c722
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2540547
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71319}

Reset main_thread_local_isolate_ only after Heap::TearDown was executed.
main_thread_local_isolate_ is still needed in there for e.g.
HandleBase::IsDereferenceAllowed in MemoryMeasurement.

Bug: chromium:1150867, v8:10315
Change-Id: Ia1ebfd561b7a3ab2d346f0c17b239f75ad77471f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2549969Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71310}

This is a reland of e95e1b62

After landing https://crrev.com/c/2546682, this CL can be relanded
without changes.

Original change's description:
> [heap] Introduce LocalIsolate for main thread
>
> Add a LocalIsolate for the main thread to Isolate. This LocalIsolate is
> kept alive during the whole lifetime of the Isolate. The main thread
> LocalIsolate starts in the Running state in contrast to the background
> thread LocalIsolates (those start in Parked).
>
> Code paths in Turbofan that used to create a LocalIsolate on the main
> thread can now simply use the main thread LocalIsolate.
>
> LocalIsolate for the main thread will help in reducing differences
> between the main and background threads. The goal is that the main
> thread behaves more like a background thread.
>
> The main thread LocalIsolate should also make it simpler to share code
> between main thread and background threads by using LocalIsolate for
> both.
>
> Bug: v8:10315
> Change-Id: I7fd61d305a6fd7079e2319d75c291c1021e70018
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2509593
> Reviewed-by: Simon Zünd <szuend@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#71226}

Bug: v8:10315
Change-Id: I418b1217aeac4f3c44a0aa514dea9864f8a58656
TBR: szuend@chromium.org, yangguo@chromium.org, ulan@chromium.org, leszeks@chromium.org, neis@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2543399Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71274}

Add a "combination" assert scope class, which combines multiple existing
assert scopes.  This will allow scopes with functional overlap, e.g.
DisallowGarbageCollection and DisallowHeapAllocation, to share an assert
type rather than rather than requiring users to remember to set both. To
demonstrate this, this redefines DisallowGarbageCollection to a
combination of DisallowHeapAllocation and a new DisallowSafepoints, and
some of the DCHECKs checking both are simplified to only check one or
the other, as appropriate.

The combination classes become subclasses of the existing assert scopes,
so that they can be used in their place as e.g. a function parameter,
e.g. DisallowGarbageCollection can be passed to a function expecting
const DisallowHeapAllocation&.

As a drive-by, this also changes the per-thread assert scopes to use a
bitmask, rather than a bool array, to store their per-thread data. The
per-isolate scopes already used a bitmask, so this unifies the
behaviour between the two.

Change-Id: I209e0a56f45e124c0ccadbd9fb77f39e070612fe
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2534814
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71231}

This reverts commit e95e1b62.

Reason for revert:
https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20arm%20-%20sim%20-%20debug/23064

Original change's description:
> [heap] Introduce LocalIsolate for main thread
>
> Add a LocalIsolate for the main thread to Isolate. This LocalIsolate is
> kept alive during the whole lifetime of the Isolate. The main thread
> LocalIsolate starts in the Running state in contrast to the background
> thread LocalIsolates (those start in Parked).
>
> Code paths in Turbofan that used to create a LocalIsolate on the main
> thread can now simply use the main thread LocalIsolate.
>
> LocalIsolate for the main thread will help in reducing differences
> between the main and background threads. The goal is that the main
> thread behaves more like a background thread.
>
> The main thread LocalIsolate should also make it simpler to share code
> between main thread and background threads by using LocalIsolate for
> both.
>
> Bug: v8:10315
> Change-Id: I7fd61d305a6fd7079e2319d75c291c1021e70018
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2509593
> Reviewed-by: Simon Zünd <szuend@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#71226}

TBR=ulan@chromium.org,yangguo@chromium.org,neis@chromium.org,leszeks@chromium.org,szuend@chromium.org,dinfuehr@chromium.org

Change-Id: Ia70b4bfe3b8fa26bf8d6a7dc612a310b0ed54073
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:10315
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2543937Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71228}

Add a LocalIsolate for the main thread to Isolate. This LocalIsolate is
kept alive during the whole lifetime of the Isolate. The main thread
LocalIsolate starts in the Running state in contrast to the background
thread LocalIsolates (those start in Parked).

Code paths in Turbofan that used to create a LocalIsolate on the main
thread can now simply use the main thread LocalIsolate.

LocalIsolate for the main thread will help in reducing differences
between the main and background threads. The goal is that the main
thread behaves more like a background thread.

The main thread LocalIsolate should also make it simpler to share code
between main thread and background threads by using LocalIsolate for
both.

Bug: v8:10315
Change-Id: I7fd61d305a6fd7079e2319d75c291c1021e70018
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2509593Reviewed-by: Simon Zünd <szuend@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71226}

Bug: v8:10927
Change-Id: Icbdc0d7329ddd466e7d67a954246a35795b4dece
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2507310
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71220}

Instead of caching only the default formatter, cache the last used
formatter if possible.

This is better because it's a common use case to create a formatter
in a different language and reuse it a lot, rather than create
several formatters in various languages.

Running the following benchmark:
```
let i = 0;

function toLocaleString() {
  i++;
  return i.toLocaleString();
}

i = 0;
function toLocaleStringWithLocale() {
  i++;
  return i.toLocaleString('en-US');
}

const functions = [toLocaleString, toLocaleStringWithLocale];

for (const f of functions) {
  let start = performance.now();
  for (let i = 0; i < 10e5; i++) {
    f();
  }
  let end = performance.now();
  print(`${f.name}: ${end - start}`);
}
```
sees the following improvements:

With this patch:
  toLocaleString: 384.292
  toLocaleStringWithLocale: 450.48900000000003

Without this patch:
  toLocaleString: 341.952
  toLocaleStringWithLocale: 23439.694

This a little over 50x improvement.

Bug: chromium:926075
Change-Id: I0e316e959c90243e175df985854832a7abddbf54
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2536461
Commit-Queue: Sathya Gunasekaran  <gsathya@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71188}

This reverts commit 8156dd85.

Reason for revert: https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Win64%20ASAN/15800/overview

Original change's description:
> GetCurrentStackPosition() -> base::Stack::GetCurrentStackPosition()
>
> Remove the duplicate utility function and use the base::Stack
> equivalent instead which provides more stack utilitiy functionality.
>
> Change-Id: Ia7a79f2530b64ceb6e2ce33445c876980b4b2a3d
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2509595
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Reviewed-by: Clemens Backes <clemensb@chromium.org>
> Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70930}

TBR=mlippautz@chromium.org,clemensb@chromium.org,verwaest@chromium.org

Change-Id: Id18949a3c82171e74370e729cd303607d46c8805
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2515431Reviewed-by: Sathya Gunasekaran  <gsathya@chromium.org>
Commit-Queue: Sathya Gunasekaran  <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70940}

Remove the duplicate utility function and use the base::Stack
equivalent instead which provides more stack utilitiy functionality.

Change-Id: Ia7a79f2530b64ceb6e2ce33445c876980b4b2a3d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2509595Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70930}

Change-Id: I7df25ca2c7caabed429cfdc0b4aab0aeb5e03fcd
Bug: v8:10201
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2463222Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70926}

.. and add a --text-is-readable flag to support non-readable .text
sections.

This splits the embedded blob hash into two dedicated hashes for data
and code sections. The main benefit is that we can now keep at least a
partial hash even with non-readable .text sections.

The second part of this CL adds a --text-is-readable runtime flag to
support such platforms (with non-readable .text).

It currently doesn't do much; setting it enables a few additional
DCHECKs, disables the constant pool on x64, and and disables
verification of the embedded blob's *code* hash.

Bug: v8:10707
Change-Id: Ib91ed8b50b50f2cd81677f62920bea6fb92af453
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2504251Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70827}

This CL provides synchronized get/set to feedback vector slots.
The FeedbackNexus is set up to use order preserving reads when used
on the background thread, and a lock to ensure coherent read
of information for ICKinds with two slots. The main thread takes
the lock on sets.

This test provides patterns to be followed by concurrent TurboFan.

We don't yet access the FeedbackVector on the background thread.
This CL only makes it safe to do so. The next step will come when
the optimizing compiler begins to query the the vector from the
background thread. Currently, with --concurrent-inlining turned on
this is done in bytecode serialization on the main thread. Without
concurrent inlining, it's also done on the main thread, in both
cases using the FeedbackNexus.

Bug: v8:7790
Change-Id: I49d8b8031190f91a0da1c24f375b6b6d8a9fe038
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2276210
Commit-Queue: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70797}

This addresses comments from [0] by extending comments to also
describe embedded builtins in code.h, and by improving language
around various meaning of 'metadata':

- The Code object's metadata section is still called 'metadata'.
- The embedded blob's table of layout descriptions for builtins is
  now called 'layout descriptions'.
- The embedded blob's data section (containing hashes and layout
  descriptions) is now called 'data' section.

[0] chromium-review.googlesource.com/c/v8/v8/+/2491025

Bug: v8:11036
Change-Id: Ibe84fddb9784cc5d3b66482612dcdb7a2e8d14ae
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2501284
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70793}

This is a reland of b66993bc

Nothing changed in the reland, the original CL was not the
culprit for win32 failures. They started earlier, at
https://ci.chromium.org/p/v8/builders/ci/V8%20Win32/29444

Original change's description:
> [code] Separate instruction and metadata areas
>
> In this CL, Code object layout changes s.t. the instruction
> area is distinct / non-overlapping from the metadata area.
>
> On-heap Code objects now have a variable-size `body` area,
> containing distinct-but-adjacent `instruction` and `metadata`
> areas.
>
> Off-heap code (= embedded builtins) currently have the same,
> but in the future the metadata area will move elsewhere and
> no longer be adjacent to instructions.
>
> To implement this, the main changes are:
>
>  - The Code object header now contains instruction and metadata
>    sizes, and no longer contains the safepoint table offset
>    (it's implicitly the first table of the metadata section).
>  - The embedded metadata table contains information about both
>    instruction and metadata areas.
>
> I've also added assertions in spots that currently rely on a
> contiguous body area.
>
> Bug: v8:11036
> Change-Id: I940f0c70c07ad511dafd2d2c3e337de8c92cd4b9
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2491025
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Clemens Backes <clemensb@chromium.org>
> Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70743}

No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Tbr: leszeks@chromium.org, clemensb@chromium.org, dinfuehr@chromium.org
Bug: v8:11036
Change-Id: I238562d7e25cf28cc689856ee8b17f25627aaee7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2497162
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Auto-Submit: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70747}

This reverts commit b66993bc.

Reason for revert: Broke v8 win32 https://ci.chromium.org/p/v8/builders/ci/V8%20Win32/29454?

Original change's description:
> [code] Separate instruction and metadata areas
>
> In this CL, Code object layout changes s.t. the instruction
> area is distinct / non-overlapping from the metadata area.
>
> On-heap Code objects now have a variable-size `body` area,
> containing distinct-but-adjacent `instruction` and `metadata`
> areas.
>
> Off-heap code (= embedded builtins) currently have the same,
> but in the future the metadata area will move elsewhere and
> no longer be adjacent to instructions.
>
> To implement this, the main changes are:
>
>  - The Code object header now contains instruction and metadata
>    sizes, and no longer contains the safepoint table offset
>    (it's implicitly the first table of the metadata section).
>  - The embedded metadata table contains information about both
>    instruction and metadata areas.
>
> I've also added assertions in spots that currently rely on a
> contiguous body area.
>
> Bug: v8:11036
> Change-Id: I940f0c70c07ad511dafd2d2c3e337de8c92cd4b9
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2491025
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Clemens Backes <clemensb@chromium.org>
> Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70743}

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

Change-Id: Ia52ac609a47b8a2038a2511f0af8526ebdfe4719
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:11036
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2497381Reviewed-by: Zhi An Ng <zhin@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70744}

In this CL, Code object layout changes s.t. the instruction
area is distinct / non-overlapping from the metadata area.

On-heap Code objects now have a variable-size `body` area,
containing distinct-but-adjacent `instruction` and `metadata`
areas.

Off-heap code (= embedded builtins) currently have the same,
but in the future the metadata area will move elsewhere and
no longer be adjacent to instructions.

To implement this, the main changes are:

 - The Code object header now contains instruction and metadata
   sizes, and no longer contains the safepoint table offset
   (it's implicitly the first table of the metadata section).
 - The embedded metadata table contains information about both
   instruction and metadata areas.

I've also added assertions in spots that currently rely on a
contiguous body area.

Bug: v8:11036
Change-Id: I940f0c70c07ad511dafd2d2c3e337de8c92cd4b9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2491025Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70743}

This is a reland of eb6b4ce1

Skip test that serializes Error which references a Script. All errors
created by ThrowAt store the current Script under the
error_script_symbol.

Original change's description:
> [runtime] Use Isolate::ThrowAt with MessageLocation
>
> Fix various missing source positions when reporting parse and compile
> errors. Namely this fixes missing source positions when having invalid
> module imports.
>
> - Use Isolate::ThrowAt with valid MessageLocation objects
> - Change public Isolate::Throw to no longer accept MessageLocation to
>   avoid misues
> - Introduce private Isolate::ThrowInternal that accepts MessageLocation
>
> Bug: v8:6513
> Change-Id: I3ee633c9fff8c9d361bddb37f56e28a50c280ec1
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2467839
> Commit-Queue: Camillo Bruni <cbruni@chromium.org>
> Reviewed-by: Marja Hölttä <marja@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70623}

Bug: v8:6513
Change-Id: Icba74f74178e28fbda0fd0c237eeb7bacbc33570
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2487123Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70741}

R=petermarshall@chromium.org, yangguo@chromium.org

Change-Id: I3d1cb354f6aeae10fda56f4c51bcb43c9fa5462c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2491028Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70710}

This is a reland of fbfa9bf4

The arm64 was missing proper codegen for CFI, thus sizes were off.

Original change's description:
> Reland "[deoptimizer] Change deopt entries into builtins"
>
> This is a reland of 7f58ced7
>
> It fixes the different exit size emitted on x64/Atom CPUs due to
> performance tuning in TurboAssembler::Call. Additionally, add
> cctests to verify the fixed size exits.
>
> Original change's description:
> > [deoptimizer] Change deopt entries into builtins
> >
> > While the overall goal of this commit is to change deoptimization
> > entries into builtins, there are multiple related things happening:
> >
> > - Deoptimization entries, formerly stubs (i.e. Code objects generated
> >   at runtime, guaranteed to be immovable), have been converted into
> >   builtins. The major restriction is that we now need to preserve the
> >   kRootRegister, which was formerly used on most architectures to pass
> >   the deoptimization id. The solution differs based on platform.
> > - Renamed DEOPT_ENTRIES_OR_FOR_TESTING code kind to FOR_TESTING.
> > - Removed heap/ support for immovable Code generation.
> > - Removed the DeserializerData class (no longer needed).
> > - arm64: to preserve 4-byte deopt exits, introduced a new optimization
> >   in which the final jump to the deoptimization entry is generated
> >   once per Code object, and deopt exits can continue to emit a
> >   near-call.
> > - arm,ia32,x64: change to fixed-size deopt exits. This reduces exit
> >   sizes by 4/8, 5, and 5 bytes, respectively.
> >
> > On arm the deopt exit size is reduced from 12 (or 16) bytes to 8 bytes
> > by using the same strategy as on arm64 (recalc deopt id from return
> > address). Before:
> >
> >  e300a002       movw r10, <id>
> >  e59fc024       ldr ip, [pc, <entry offset>]
> >  e12fff3c       blx ip
> >
> > After:
> >
> >  e59acb35       ldr ip, [r10, <entry offset>]
> >  e12fff3c       blx ip
> >
> > On arm64 the deopt exit size remains 4 bytes (or 8 bytes in same cases
> > with CFI). Additionally, up to 4 builtin jumps are emitted per Code
> > object (max 32 bytes added overhead per Code object). Before:
> >
> >  9401cdae       bl <entry offset>
> >
> > After:
> >
> >  # eager deoptimization entry jump.
> >  f95b1f50       ldr x16, [x26, <eager entry offset>]
> >  d61f0200       br x16
> >  # lazy deoptimization entry jump.
> >  f95b2b50       ldr x16, [x26, <lazy entry offset>]
> >  d61f0200       br x16
> >  # the deopt exit.
> >  97fffffc       bl <eager deoptimization entry jump offset>
> >
> > On ia32 the deopt exit size is reduced from 10 to 5 bytes. Before:
> >
> >  bb00000000     mov ebx,<id>
> >  e825f5372b     call <entry>
> >
> > After:
> >
> >  e8ea2256ba     call <entry>
> >
> > On x64 the deopt exit size is reduced from 12 to 7 bytes. Before:
> >
> >  49c7c511000000 REX.W movq r13,<id>
> >  e8ea2f0700     call <entry>
> >
> > After:
> >
> >  41ff9560360000 call [r13+<entry offset>]
> >
> > Bug: v8:8661,v8:8768
> > Change-Id: I13e30aedc360474dc818fecc528ce87c3bfeed42
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2465834
> > Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> > Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> > Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#70597}
>
> Tbr: ulan@chromium.org, tebbi@chromium.org, rmcilroy@chromium.org
> Bug: v8:8661,v8:8768,chromium:1140165
> Change-Id: Ibcd5c39c58a70bf2b2ac221aa375fc68d495e144
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485506
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70655}

Tbr: ulan@chromium.org, tebbi@chromium.org, rmcilroy@chromium.org
Bug: v8:8661
Bug: v8:8768
Bug: chromium:1140165
Change-Id: I471cc94fc085e527dc9bfb5a84b96bd907c2333f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2488682Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70672}

This reverts commit fbfa9bf4.

Reason for revert: Seems to break arm64 sim CFI build (please see DeoptExitSizeIfFixed) - https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20arm64%20-%20sim%20-%20CFI/2808

Original change's description:
> Reland "[deoptimizer] Change deopt entries into builtins"
>
> This is a reland of 7f58ced7
>
> It fixes the different exit size emitted on x64/Atom CPUs due to
> performance tuning in TurboAssembler::Call. Additionally, add
> cctests to verify the fixed size exits.
>
> Original change's description:
> > [deoptimizer] Change deopt entries into builtins
> >
> > While the overall goal of this commit is to change deoptimization
> > entries into builtins, there are multiple related things happening:
> >
> > - Deoptimization entries, formerly stubs (i.e. Code objects generated
> >   at runtime, guaranteed to be immovable), have been converted into
> >   builtins. The major restriction is that we now need to preserve the
> >   kRootRegister, which was formerly used on most architectures to pass
> >   the deoptimization id. The solution differs based on platform.
> > - Renamed DEOPT_ENTRIES_OR_FOR_TESTING code kind to FOR_TESTING.
> > - Removed heap/ support for immovable Code generation.
> > - Removed the DeserializerData class (no longer needed).
> > - arm64: to preserve 4-byte deopt exits, introduced a new optimization
> >   in which the final jump to the deoptimization entry is generated
> >   once per Code object, and deopt exits can continue to emit a
> >   near-call.
> > - arm,ia32,x64: change to fixed-size deopt exits. This reduces exit
> >   sizes by 4/8, 5, and 5 bytes, respectively.
> >
> > On arm the deopt exit size is reduced from 12 (or 16) bytes to 8 bytes
> > by using the same strategy as on arm64 (recalc deopt id from return
> > address). Before:
> >
> >  e300a002       movw r10, <id>
> >  e59fc024       ldr ip, [pc, <entry offset>]
> >  e12fff3c       blx ip
> >
> > After:
> >
> >  e59acb35       ldr ip, [r10, <entry offset>]
> >  e12fff3c       blx ip
> >
> > On arm64 the deopt exit size remains 4 bytes (or 8 bytes in same cases
> > with CFI). Additionally, up to 4 builtin jumps are emitted per Code
> > object (max 32 bytes added overhead per Code object). Before:
> >
> >  9401cdae       bl <entry offset>
> >
> > After:
> >
> >  # eager deoptimization entry jump.
> >  f95b1f50       ldr x16, [x26, <eager entry offset>]
> >  d61f0200       br x16
> >  # lazy deoptimization entry jump.
> >  f95b2b50       ldr x16, [x26, <lazy entry offset>]
> >  d61f0200       br x16
> >  # the deopt exit.
> >  97fffffc       bl <eager deoptimization entry jump offset>
> >
> > On ia32 the deopt exit size is reduced from 10 to 5 bytes. Before:
> >
> >  bb00000000     mov ebx,<id>
> >  e825f5372b     call <entry>
> >
> > After:
> >
> >  e8ea2256ba     call <entry>
> >
> > On x64 the deopt exit size is reduced from 12 to 7 bytes. Before:
> >
> >  49c7c511000000 REX.W movq r13,<id>
> >  e8ea2f0700     call <entry>
> >
> > After:
> >
> >  41ff9560360000 call [r13+<entry offset>]
> >
> > Bug: v8:8661,v8:8768
> > Change-Id: I13e30aedc360474dc818fecc528ce87c3bfeed42
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2465834
> > Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> > Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> > Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#70597}
>
> Tbr: ulan@chromium.org, tebbi@chromium.org, rmcilroy@chromium.org
> Bug: v8:8661,v8:8768,chromium:1140165
> Change-Id: Ibcd5c39c58a70bf2b2ac221aa375fc68d495e144
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485506
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70655}

TBR=ulan@chromium.org,rmcilroy@chromium.org,jgruber@chromium.org,tebbi@chromium.org

Change-Id: I4739a3475bfd8ee0cfbe4b9a20382f91a6ef1bf0
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8661
Bug: v8:8768
Bug: chromium:1140165
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485223Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70658}

This is a reland of 7f58ced7

It fixes the different exit size emitted on x64/Atom CPUs due to
performance tuning in TurboAssembler::Call. Additionally, add
cctests to verify the fixed size exits.

Original change's description:
> [deoptimizer] Change deopt entries into builtins
>
> While the overall goal of this commit is to change deoptimization
> entries into builtins, there are multiple related things happening:
>
> - Deoptimization entries, formerly stubs (i.e. Code objects generated
>   at runtime, guaranteed to be immovable), have been converted into
>   builtins. The major restriction is that we now need to preserve the
>   kRootRegister, which was formerly used on most architectures to pass
>   the deoptimization id. The solution differs based on platform.
> - Renamed DEOPT_ENTRIES_OR_FOR_TESTING code kind to FOR_TESTING.
> - Removed heap/ support for immovable Code generation.
> - Removed the DeserializerData class (no longer needed).
> - arm64: to preserve 4-byte deopt exits, introduced a new optimization
>   in which the final jump to the deoptimization entry is generated
>   once per Code object, and deopt exits can continue to emit a
>   near-call.
> - arm,ia32,x64: change to fixed-size deopt exits. This reduces exit
>   sizes by 4/8, 5, and 5 bytes, respectively.
>
> On arm the deopt exit size is reduced from 12 (or 16) bytes to 8 bytes
> by using the same strategy as on arm64 (recalc deopt id from return
> address). Before:
>
>  e300a002       movw r10, <id>
>  e59fc024       ldr ip, [pc, <entry offset>]
>  e12fff3c       blx ip
>
> After:
>
>  e59acb35       ldr ip, [r10, <entry offset>]
>  e12fff3c       blx ip
>
> On arm64 the deopt exit size remains 4 bytes (or 8 bytes in same cases
> with CFI). Additionally, up to 4 builtin jumps are emitted per Code
> object (max 32 bytes added overhead per Code object). Before:
>
>  9401cdae       bl <entry offset>
>
> After:
>
>  # eager deoptimization entry jump.
>  f95b1f50       ldr x16, [x26, <eager entry offset>]
>  d61f0200       br x16
>  # lazy deoptimization entry jump.
>  f95b2b50       ldr x16, [x26, <lazy entry offset>]
>  d61f0200       br x16
>  # the deopt exit.
>  97fffffc       bl <eager deoptimization entry jump offset>
>
> On ia32 the deopt exit size is reduced from 10 to 5 bytes. Before:
>
>  bb00000000     mov ebx,<id>
>  e825f5372b     call <entry>
>
> After:
>
>  e8ea2256ba     call <entry>
>
> On x64 the deopt exit size is reduced from 12 to 7 bytes. Before:
>
>  49c7c511000000 REX.W movq r13,<id>
>  e8ea2f0700     call <entry>
>
> After:
>
>  41ff9560360000 call [r13+<entry offset>]
>
> Bug: v8:8661,v8:8768
> Change-Id: I13e30aedc360474dc818fecc528ce87c3bfeed42
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2465834
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70597}

Tbr: ulan@chromium.org, tebbi@chromium.org, rmcilroy@chromium.org
Bug: v8:8661,v8:8768,chromium:1140165
Change-Id: Ibcd5c39c58a70bf2b2ac221aa375fc68d495e144
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485506Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70655}

This reverts commit 7f58ced7.

Reason for revert: Segfaults on Atom_x64 https://ci.chromium.org/p/v8-internal/builders/ci/v8_linux64_atom_perf/5686?

Original change's description:
> [deoptimizer] Change deopt entries into builtins
>
> While the overall goal of this commit is to change deoptimization
> entries into builtins, there are multiple related things happening:
>
> - Deoptimization entries, formerly stubs (i.e. Code objects generated
>   at runtime, guaranteed to be immovable), have been converted into
>   builtins. The major restriction is that we now need to preserve the
>   kRootRegister, which was formerly used on most architectures to pass
>   the deoptimization id. The solution differs based on platform.
> - Renamed DEOPT_ENTRIES_OR_FOR_TESTING code kind to FOR_TESTING.
> - Removed heap/ support for immovable Code generation.
> - Removed the DeserializerData class (no longer needed).
> - arm64: to preserve 4-byte deopt exits, introduced a new optimization
>   in which the final jump to the deoptimization entry is generated
>   once per Code object, and deopt exits can continue to emit a
>   near-call.
> - arm,ia32,x64: change to fixed-size deopt exits. This reduces exit
>   sizes by 4/8, 5, and 5 bytes, respectively.
>
> On arm the deopt exit size is reduced from 12 (or 16) bytes to 8 bytes
> by using the same strategy as on arm64 (recalc deopt id from return
> address). Before:
>
>  e300a002       movw r10, <id>
>  e59fc024       ldr ip, [pc, <entry offset>]
>  e12fff3c       blx ip
>
> After:
>
>  e59acb35       ldr ip, [r10, <entry offset>]
>  e12fff3c       blx ip
>
> On arm64 the deopt exit size remains 4 bytes (or 8 bytes in same cases
> with CFI). Additionally, up to 4 builtin jumps are emitted per Code
> object (max 32 bytes added overhead per Code object). Before:
>
>  9401cdae       bl <entry offset>
>
> After:
>
>  # eager deoptimization entry jump.
>  f95b1f50       ldr x16, [x26, <eager entry offset>]
>  d61f0200       br x16
>  # lazy deoptimization entry jump.
>  f95b2b50       ldr x16, [x26, <lazy entry offset>]
>  d61f0200       br x16
>  # the deopt exit.
>  97fffffc       bl <eager deoptimization entry jump offset>
>
> On ia32 the deopt exit size is reduced from 10 to 5 bytes. Before:
>
>  bb00000000     mov ebx,<id>
>  e825f5372b     call <entry>
>
> After:
>
>  e8ea2256ba     call <entry>
>
> On x64 the deopt exit size is reduced from 12 to 7 bytes. Before:
>
>  49c7c511000000 REX.W movq r13,<id>
>  e8ea2f0700     call <entry>
>
> After:
>
>  41ff9560360000 call [r13+<entry offset>]
>
> Bug: v8:8661,v8:8768
> Change-Id: I13e30aedc360474dc818fecc528ce87c3bfeed42
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2465834
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70597}

TBR=ulan@chromium.org,rmcilroy@chromium.org,jgruber@chromium.org,tebbi@chromium.org

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

Bug: v8:8661,v8:8768,chromium:1140165
Change-Id: I3df02ab42f6e02233d9f6fb80e8bb18f76870d91
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485504Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70649}

This is a reland of c5379162

The reland fixes Code::clear_padding to correctly clear trailing
padding.

Original change's description:
> [code] Move the unwinding info into metadata area
>
> Semantically, the unwinding info is a variable-size metadata table
> with untagged (i.e. no relocation needed) contents, packed inside Code
> objects. This is just like other metadata tables (safepoint table,
> handler table, constant pool, code comments); but for historical
> reasons it's been treated differently so far. Unlike these other
> tables, the unwinding info was located *after* InstructionEnd, and its
> size was written to the first 8 bytes after InstructionEnd.
>
> This CL makes unwinding info handling more consistent with other
> metadata tables by writing its offset into a dedicated
> kUnwindingInfoOffsetOffset header slot, and by moving the actual data
> inside the [InstructionStart,InstructionEnd[ area. In follow-up CLs,
> this area will be split into dedicated instruction- and metadata
> areas.
>
> A picture is worth 1000 words, before:
>
>  +--------------------------+  <-- raw_instruction_start()
>  |       instructions       |
>  |           ...            |
>  +--------------------------+
>  |     embedded metadata    |  <-- safepoint_table_offset()
>  |           ...            |  <-- handler_table_offset()
>  |                          |  <-- constant_pool_offset()
>  |                          |  <-- code_comments_offset()
>  |    padding to the next   |
>  |  8-byte aligned address  |
>  +--------------------------+  <-- raw_instruction_end()
>  |   [unwinding_info_size]  |
>  |        as uint64_t       |
>  +--------------------------+  <-- unwinding_info_start()
>  |       unwinding info     |
>  |            ...           |
>  +--------------------------+  <-- unwinding_info_end()
>
> After:
>
>  +--------------------------+  <-- raw_instruction_start()
>  |       instructions       |
>  |           ...            |
>  +--------------------------+
>  |     embedded metadata    |  <-- safepoint_table_offset()
>  |           ...            |  <-- handler_table_offset()
>  |                          |  <-- constant_pool_offset()
>  |                          |  <-- code_comments_offset()
>  |                          |  <-- unwinding_info_offset()
>  |                          |
>  +--------------------------+  <-- raw_instruction_end()
>
> Bug: v8:11036
> Change-Id: I649708821acc5365186ca2c9cff2669fc3e91fd3
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2484795
> Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70640}

Cq-Include-Trybots: luci.v8.try:v8_linux64_msan_rel_ng
Tbr: leszeks@chromium.org
Bug: v8:11036
Change-Id: I2ea056fe2a53217e0b5ae25661b92f5ddec6fca5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485501
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70645}

This reverts commit c5379162.

Reason for revert: Seems to cause MSAN failure - https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20arm64%20-%20sim%20-%20MSAN/34931

Original change's description:
> [code] Move the unwinding info into metadata area
>
> Semantically, the unwinding info is a variable-size metadata table
> with untagged (i.e. no relocation needed) contents, packed inside Code
> objects. This is just like other metadata tables (safepoint table,
> handler table, constant pool, code comments); but for historical
> reasons it's been treated differently so far. Unlike these other
> tables, the unwinding info was located *after* InstructionEnd, and its
> size was written to the first 8 bytes after InstructionEnd.
>
> This CL makes unwinding info handling more consistent with other
> metadata tables by writing its offset into a dedicated
> kUnwindingInfoOffsetOffset header slot, and by moving the actual data
> inside the [InstructionStart,InstructionEnd[ area. In follow-up CLs,
> this area will be split into dedicated instruction- and metadata
> areas.
>
> A picture is worth 1000 words, before:
>
>  +--------------------------+  <-- raw_instruction_start()
>  |       instructions       |
>  |           ...            |
>  +--------------------------+
>  |     embedded metadata    |  <-- safepoint_table_offset()
>  |           ...            |  <-- handler_table_offset()
>  |                          |  <-- constant_pool_offset()
>  |                          |  <-- code_comments_offset()
>  |    padding to the next   |
>  |  8-byte aligned address  |
>  +--------------------------+  <-- raw_instruction_end()
>  |   [unwinding_info_size]  |
>  |        as uint64_t       |
>  +--------------------------+  <-- unwinding_info_start()
>  |       unwinding info     |
>  |            ...           |
>  +--------------------------+  <-- unwinding_info_end()
>
> After:
>
>  +--------------------------+  <-- raw_instruction_start()
>  |       instructions       |
>  |           ...            |
>  +--------------------------+
>  |     embedded metadata    |  <-- safepoint_table_offset()
>  |           ...            |  <-- handler_table_offset()
>  |                          |  <-- constant_pool_offset()
>  |                          |  <-- code_comments_offset()
>  |                          |  <-- unwinding_info_offset()
>  |                          |
>  +--------------------------+  <-- raw_instruction_end()
>
> Bug: v8:11036
> Change-Id: I649708821acc5365186ca2c9cff2669fc3e91fd3
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2484795
> Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70640}

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

Change-Id: If8417f88f4c55771e455ec85f5efdc6343671ad3
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:11036
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485500Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70641}

Semantically, the unwinding info is a variable-size metadata table
with untagged (i.e. no relocation needed) contents, packed inside Code
objects. This is just like other metadata tables (safepoint table,
handler table, constant pool, code comments); but for historical
reasons it's been treated differently so far. Unlike these other
tables, the unwinding info was located *after* InstructionEnd, and its
size was written to the first 8 bytes after InstructionEnd.

This CL makes unwinding info handling more consistent with other
metadata tables by writing its offset into a dedicated
kUnwindingInfoOffsetOffset header slot, and by moving the actual data
inside the [InstructionStart,InstructionEnd[ area. In follow-up CLs,
this area will be split into dedicated instruction- and metadata
areas.

A picture is worth 1000 words, before:

 +--------------------------+  <-- raw_instruction_start()
 |       instructions       |
 |           ...            |
 +--------------------------+
 |     embedded metadata    |  <-- safepoint_table_offset()
 |           ...            |  <-- handler_table_offset()
 |                          |  <-- constant_pool_offset()
 |                          |  <-- code_comments_offset()
 |    padding to the next   |
 |  8-byte aligned address  |
 +--------------------------+  <-- raw_instruction_end()
 |   [unwinding_info_size]  |
 |        as uint64_t       |
 +--------------------------+  <-- unwinding_info_start()
 |       unwinding info     |
 |            ...           |
 +--------------------------+  <-- unwinding_info_end()

After:

 +--------------------------+  <-- raw_instruction_start()
 |       instructions       |
 |           ...            |
 +--------------------------+
 |     embedded metadata    |  <-- safepoint_table_offset()
 |           ...            |  <-- handler_table_offset()
 |                          |  <-- constant_pool_offset()
 |                          |  <-- code_comments_offset()
 |                          |  <-- unwinding_info_offset()
 |                          |
 +--------------------------+  <-- raw_instruction_end()

Bug: v8:11036
Change-Id: I649708821acc5365186ca2c9cff2669fc3e91fd3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2484795Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70640}

This reverts commit eb6b4ce1.

Reason for revert: Might need rebaseline:
https://ci.chromium.org/p/v8/builders/ci/V8%20Blink%20Linux/7519

Original change's description:
> [runtime] Use Isolate::ThrowAt with MessageLocation
>
> Fix various missing source positions when reporting parse and compile
> errors. Namely this fixes missing source positions when having invalid
> module imports.
>
> - Use Isolate::ThrowAt with valid MessageLocation objects
> - Change public Isolate::Throw to no longer accept MessageLocation to
>   avoid misues
> - Introduce private Isolate::ThrowInternal that accepts MessageLocation
>
> Bug: v8:6513
> Change-Id: I3ee633c9fff8c9d361bddb37f56e28a50c280ec1
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2467839
> Commit-Queue: Camillo Bruni <cbruni@chromium.org>
> Reviewed-by: Marja Hölttä <marja@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70623}

TBR=marja@chromium.org,cbruni@chromium.org,ishell@chromium.org

Change-Id: Ifa16ef8b6e5e411712fbad2e2a58fd700da12a69
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:6513
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485498Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70631}

Fix various missing source positions when reporting parse and compile
errors. Namely this fixes missing source positions when having invalid
module imports.

- Use Isolate::ThrowAt with valid MessageLocation objects
- Change public Isolate::Throw to no longer accept MessageLocation to
  avoid misues
- Introduce private Isolate::ThrowInternal that accepts MessageLocation

Bug: v8:6513
Change-Id: I3ee633c9fff8c9d361bddb37f56e28a50c280ec1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2467839
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70623}

While the overall goal of this commit is to change deoptimization
entries into builtins, there are multiple related things happening:

- Deoptimization entries, formerly stubs (i.e. Code objects generated
  at runtime, guaranteed to be immovable), have been converted into
  builtins. The major restriction is that we now need to preserve the
  kRootRegister, which was formerly used on most architectures to pass
  the deoptimization id. The solution differs based on platform.
- Renamed DEOPT_ENTRIES_OR_FOR_TESTING code kind to FOR_TESTING.
- Removed heap/ support for immovable Code generation.
- Removed the DeserializerData class (no longer needed).
- arm64: to preserve 4-byte deopt exits, introduced a new optimization
  in which the final jump to the deoptimization entry is generated
  once per Code object, and deopt exits can continue to emit a
  near-call.
- arm,ia32,x64: change to fixed-size deopt exits. This reduces exit
  sizes by 4/8, 5, and 5 bytes, respectively.

On arm the deopt exit size is reduced from 12 (or 16) bytes to 8 bytes
by using the same strategy as on arm64 (recalc deopt id from return
address). Before:

 e300a002       movw r10, <id>
 e59fc024       ldr ip, [pc, <entry offset>]
 e12fff3c       blx ip

After:

 e59acb35       ldr ip, [r10, <entry offset>]
 e12fff3c       blx ip

On arm64 the deopt exit size remains 4 bytes (or 8 bytes in same cases
with CFI). Additionally, up to 4 builtin jumps are emitted per Code
object (max 32 bytes added overhead per Code object). Before:

 9401cdae       bl <entry offset>

After:

 # eager deoptimization entry jump.
 f95b1f50       ldr x16, [x26, <eager entry offset>]
 d61f0200       br x16
 # lazy deoptimization entry jump.
 f95b2b50       ldr x16, [x26, <lazy entry offset>]
 d61f0200       br x16
 # the deopt exit.
 97fffffc       bl <eager deoptimization entry jump offset>

On ia32 the deopt exit size is reduced from 10 to 5 bytes. Before:

 bb00000000     mov ebx,<id>
 e825f5372b     call <entry>

After:

 e8ea2256ba     call <entry>

On x64 the deopt exit size is reduced from 12 to 7 bytes. Before:

 49c7c511000000 REX.W movq r13,<id>
 e8ea2f0700     call <entry>

After:

 41ff9560360000 call [r13+<entry offset>]

Bug: v8:8661,v8:8768
Change-Id: I13e30aedc360474dc818fecc528ce87c3bfeed42
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2465834
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70597}

- Use kNoBuiltinId instead of literal -1.
- Remove support for non-embedded builtins.
- Update Code object layout comment.

Bug: v8:10933
Change-Id: Ie75c6ccc0a0f19348ae214249a8fc81f7e91df0c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2474115
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Auto-Submit: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70557}

- Add a frame inheritance hierarchy comment.
- Rename StandardFrame from frame.h to CommonFrame: StandardFrame usually means a JavaScript frame in other files.
- Create a TypedFrame and adjust every frame that depends on it.

Change-Id: I105a4ba95954c02e43bcbe2b677e554b9e9af092
Bug: v8:10933
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2431568
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70532}

Code objects for builtins are immortal and immovable and can thus be
dereferenced like read-only-objects.

Bug: v8:10315
Change-Id: I60d961fee71056160ad2913bffe3ca50280cb9d2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2465835Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70471}

This relands commit 3f4e9bbe.
which was a reland of c4a062a9
which was a reland of 28a30c57
which was a reland of 5d7a29c9

The change had an issue that embedders implementing heap tracing (e.g.
Unified Heap with Blink) could be passed an uninitialized pointer if
marking happened during deserialization of an object containing such a
pointer. Because of the 0xdeadbed0 uninitialized filler value, these
embedders would then receive the value 0xdeadbed0deadbed0 as the
'pointer', and crash on dereference.

There is, however, special handling already for null pointers in heap
tracing, also for dealing with not-yet initialized values. So, we can
make the uninitialized Smi filler be 0x00000000, and that will make such
embedded fields have a nullptr representation, making them follow the
normal uninitialized value bailouts.

In addition, it relands the following dependent changes, which are
relanding unchanged and are followup performance improvements.
Relanding them in the same change should allow for cleaner reverts
should they be needed.

This relands commit 76ad3ab5
[identity-map] Change resize heuristic

This relands commit 77cc96aa
[identity-map] Cache the calculated Hash

This relands commit bee5b996
[serializer] Remove Deserializer::Initialize

This relands commit c8f73f22
[serializer] Cache instance type in PostProcessNewObject

This relands commit 4e7c99ab
[identity-map] Remove double-lookups in IdentityMap

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: Ib514a4ef16bd02bfb60d046ecbf8fae1ead64a98
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2452689
Commit-Queue: 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@{#70366}

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}

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}

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}

This reverts commit c4a062a9.

Reason for revert: TSan issues: https://ci.chromium.org/p/v8/builders/ci/V8%20Linux64%20TSAN/33504

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

Change-Id: Ib2f01db4cd9b55639d6a4af971bda865edb45e84
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:1075999
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2445250Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70280}