Original message:

Calling Runtime::kAbort through a builtin instead of the c-entry stub
will allow to generate the call in a background thread, because a
builtin provides its own handle, whereas a code stub does not.

@v8-mips-ports: Could you take a special look at the padding that is
done in MacroAssembler::Abort()?

Reason for revert:
The reason for reverting is: Blocks roll:
https://build.chromium.org/p/client.v8.ports/builders/V8%20Linux%20-%20arm64%20-%20sim%20-%20debug/builds/1622

The problem was that on arm64 the builtin for Abort() contained a call to
Abort(). The problem is fixed by using a NoUseRealAbortsScope in the
code generation of Abort().

R=titzer@chromium.org, rmcilroy@chromium.org, rodolph.perfetta@arm.com

Review-Url: https://codereview.chromium.org/2163263002
Cr-Commit-Position: refs/heads/master@{#37929}

We can actually eliminate certain effectful operations like loads and
speculative number operations during representation selection if we
discover that their value outputs are unused (we also propagate this
information through pure operations as well, so that we remove the
maximum number of effectful nodes possible).

R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2168023002
Cr-Commit-Position: refs/heads/master@{#37928}

Revert of Remove stack overflow boilerplate (patchset #3 id:40001 of https://codereview.chromium.org/2161953003/ )

Reason for revert:
Clusterfuzz failures in parent CL https://codereview.chromium.org/2142933003/

Original issue's description:
> Remove stack overflow boilerplate
>
> We no longer need to prepare the stack overflow error in advance now that
> Errors are constructed in C++.
>
> R=yangguo@chromium.org
> BUG=
>
> Committed: https://crrev.com/ba95d10ccbe13e2fca427228483b045576f2dc4c
> Cr-Commit-Position: refs/heads/master@{#37923}

TBR=yangguo@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review-Url: https://codereview.chromium.org/2169563003
Cr-Commit-Position: refs/heads/master@{#37927}

Because of the somewhat strange way default toolchains and custom
toolchains and user-specified arguments work in GN, if you did a v8
build that just set v8_target_cpu, you could end up building two
identical copies of v8 (see the comments in the change for more).

This CL identifies that case and fixes it.

R=machenbach@chromium.org
BUG=629825

Review-Url: https://codereview.chromium.org/2166173002
Cr-Commit-Position: refs/heads/master@{#37926}

Revert of [Intepreter] Always use BytecodeGraphBuilder when --turbo-from-bytecode (patchset #3 id:80001 of https://codereview.chromium.org/2156753002/ )

Reason for revert:
Breaks tsan:
https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20TSAN/builds/10758

Original issue's description:
> [Intepreter] Always use BytecodeGraphBuilder when --turbo-from-bytecode
>
> Always use the BytecodeGraphBuilder when the  --turbo-from-bytecode
> is enabled, assuming the function should be compiled for Ignition.
> Adds a new MaybeOptimizeIgnition function to runtime-profiler
> which is called if the function should be optimized from bytecode
> rather than going via full-codegen.
>
> BUG=v8:4280
>
> Committed: https://crrev.com/9ca7db914be88e6792a88eab4a1988ee031d70c4
> Cr-Commit-Position: refs/heads/master@{#37921}

TBR=mstarzinger@chromium.org,rmcilroy@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4280

Review-Url: https://codereview.chromium.org/2165223002
Cr-Commit-Position: refs/heads/master@{#37925}

R=machenbach@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2167723004
Cr-Commit-Position: refs/heads/master@{#37924}

We no longer need to prepare the stack overflow error in advance now that
Errors are constructed in C++.

R=yangguo@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2161953003
Cr-Commit-Position: refs/heads/master@{#37923}

R=franzih@chromium.org

Review-Url: https://codereview.chromium.org/2157363005
Cr-Commit-Position: refs/heads/master@{#37922}

Always use the BytecodeGraphBuilder when the  --turbo-from-bytecode
is enabled, assuming the function should be compiled for Ignition.
Adds a new MaybeOptimizeIgnition function to runtime-profiler
which is called if the function should be optimized from bytecode
rather than going via full-codegen.

BUG=v8:4280

Review-Url: https://codereview.chromium.org/2156753002
Cr-Commit-Position: refs/heads/master@{#37921}

Putting SloppyBlockFunctionStatement into local_zone_ was too early. It
needs to go into parser_zone_ because Scope refers to it. It will be
moved back to local_zone_ when we can put Scopes into temporary Zones.

A test (to demonstrate we crash without this CL) will follow in a separate CL.

R=verwaest@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2170813002
Cr-Commit-Position: refs/heads/master@{#37920}

The optimizing compilers actually invoke %TransitionElementsKind for
any kind of JSObject, the only relevant thing is the elements kind.
The runtime function was however checking for JSArray unnecessarily.
This only worked by coincindence in Crankshaft because the stub would
normally not call into the runtime fallback.

R=jarin@chromium.org
BUG=chromium:629823

Review-Url: https://codereview.chromium.org/2166963004
Cr-Commit-Position: refs/heads/master@{#37919}

BUG=

Review-Url: https://codereview.chromium.org/2166633003
Cr-Commit-Position: refs/heads/master@{#37918}

Rolling v8/base/trace_event/common to 315bf1e2d45be7d53346c31cfcc37424a32c30c8

Rolling v8/build to 47d75963ee42a9b9688e4f85c097b3a15d4f2bb2

Rolling v8/buildtools to 60f7f9a8b421ebf9a46041dfa2ff11c0fe59c582

Rolling v8/tools/mb to 1815b6867db701b1bba1c223e4f67811196122ea

TBR=machenbach@chromium.org,vogelheim@chromium.org,hablich@chromium.org

Review-Url: https://codereview.chromium.org/2168733003
Cr-Commit-Position: refs/heads/master@{#37917}

There is simply no point in converting between relative and absolute source
positions in both C++ and Javascript code.

R=jgruber@chromium.org

Review-Url: https://codereview.chromium.org/2169463002
Cr-Commit-Position: refs/heads/master@{#37916}

Fixes bug in test-gap-resolver.cc that didn't test different move reps.
Fixes test canonicalization so all slots have the same type (non-float).
Improve test failure text output.

LOG=N
BUG=v8:5187

Review-Url: https://codereview.chromium.org/2169493002
Cr-Commit-Position: refs/heads/master@{#37915}

SharedFunctionInfo::name is always a String if present (never a Symbol),
so there's no need to first test it for IsName() before testing IsString().
This is enforced by a check in %FunctionSetName.

As a bonus, the code no longer looks invalid (unconditionally casting
a Name to a String). The logic came into this broken-looking state
accidentally in the flag cleanup CL https://codereview.chromium.org/2096933002/.

Review-Url: https://codereview.chromium.org/2162853003
Cr-Commit-Position: refs/heads/master@{#37914}

Allows jitted code to be annotated in perf. To use:

1) Report generated code in code-(pid)-1.asm.

  perf record -- d8 --print-code --redirect-code-traces script.js

2) Run perf report from the directory containing the above code file.

  perf report --objdump=v8/tools/objdump-v8

This script supports generated code from both crankshaft or turbofan.

BUG=

Review-Url: https://codereview.chromium.org/2167553002
Cr-Commit-Position: refs/heads/master@{#37913}

NewScope automatically uses scope(), whereas NewScopeWithParent can pass along any local Scope* as outer scope. The number of calls to NewScopeWithParent should be reduced over time.

BUG=v8:5209

Review-Url: https://codereview.chromium.org/2164943002
Cr-Commit-Position: refs/heads/master@{#37912}

This CL more or less reverts commit https://codereview.chromium.org/2107733002/
The use of the MathPow code stub that was introduced by that commit caused
problems on arm64, and the MathPow code stub was also an obstacle in the
implementation of parallel code generation.

In addition this CL turns on the mjsunit/wasm/embenchen tests for arm64
which were turned off because of problems with MathPow on arm64.

R=titzer@chromium.org, bradnelson@chromium.org

Review-Url: https://codereview.chromium.org/2166793002
Cr-Commit-Position: refs/heads/master@{#37911}

This CL fixes weird performance implications when changing layout of Code::flags field:
it happened that the unused ICStateField with MONOMORPHIC value in the handlers' flags
was accidentally offsetting the underflow bug in stub cache probing code on arm, arm64,
mips and mips64.

Stub cache tests now work even when snapshot is enabled.

Drive-by-change: Fixed counters manipulation on arm64 and mips64.

BUG=chromium:618701

Review-Url: https://codereview.chromium.org/2161153002
Cr-Commit-Position: refs/heads/master@{#37910}

R=yangguo@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2163933002
Cr-Commit-Position: refs/heads/master@{#37909}

This ports a large portion of Error methods to C++,
including the constructor, stack setter and getter,
and Error.prototype.toString.

BUG=

Committed: https://crrev.com/5742da056a290caa13a0b8717ddb1e43424e0d31
Review-Url: https://codereview.chromium.org/2142933003
Cr-Original-Commit-Position: refs/heads/master@{#37870}
Cr-Commit-Position: refs/heads/master@{#37908}

It's the only Scope type that has outer scope nullptr; and it always has outer scope nullptr.

BUG=v8:5209

Review-Url: https://codereview.chromium.org/2158913005
Cr-Commit-Position: refs/heads/master@{#37907}

BUG=v8:5215
R=marja@chromium.org

Review-Url: https://codereview.chromium.org/2161033003
Cr-Commit-Position: refs/heads/master@{#37906}

That way, backtraces should work

BUG=
R=machenbach@chromium.org

Review-Url: https://codereview.chromium.org/2168593002
Cr-Commit-Position: refs/heads/master@{#37905}

For some bytecodes it is beneficial to always look for a Star
bytecode when dispatching to the next and inline perform it
without dispatching to the Star handler.

BUG=v8:4280
LOG=N

Review-Url: https://codereview.chromium.org/2142273003
Cr-Commit-Position: refs/heads/master@{#37904}

BUG=chromium:629025
NOTRY=true
NOPRESUBMIT=true
TBR=sergiyb@chromium.org

Review-Url: https://codereview.chromium.org/2165883003
Cr-Commit-Position: refs/heads/master@{#37903}

This additionally makes the invariant obvious that outer_scope==nullptr+is_with_scope is impossible.

BUG=v8:5209

Review-Url: https://codereview.chromium.org/2165923002
Cr-Commit-Position: refs/heads/master@{#37902}

It takes the number of additional elements, not the total target
capacity.

Also, avoid right-shifting a negative integer as this is undefined in general

BUG=v8:4909
R=verwaest@chromium.org

Review-Url: https://codereview.chromium.org/2162333002
Cr-Commit-Position: refs/heads/master@{#37901}

By now TurboFan is shipping on a broad range of language constructs and
wholesale disabling TurboFan can still be done with the --turbo-filter
flag. A dedicated flag controlling AST numbering heuristics is no longer
needed.

R=bmeurer@chromium.org

Review-Url: https://codereview.chromium.org/2155243006
Cr-Commit-Position: refs/heads/master@{#37900}

Revert of [turbofan] Introduce TruncateTaggedToBit operator for ToBoolean truncation. (patchset #2 id:20001 of https://codereview.chromium.org/2167593002/ )

Reason for revert:
Breaks arm64 gc stress:
https://build.chromium.org/p/client.v8.ports/builders/V8%20Linux%20-%20arm64%20-%20sim%20-%20gc%20stress/builds/1605

Original issue's description:
> [turbofan] Introduce TruncateTaggedToBit operator for ToBoolean truncation.
>
> Add a dedicated simplified operator to inline the general case for the
> ToBoolean conversion. In a follow up CL we will also use the ToBoolean
> hints gathered by the baseline compiler.
>
> Committed: https://crrev.com/8c50b51ab3d21efcd2f6900d83962159f21e1590
> Cr-Commit-Position: refs/heads/master@{#37882}

TBR=jarin@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review-Url: https://codereview.chromium.org/2170433002
Cr-Commit-Position: refs/heads/master@{#37899}

This creates the guarantee that we can compute the parent scope later on. We'll do the same for other types of scopes as well (with perhaps a limited number of exceptions that will need to be eagerly allocated).

BUG=v8:5209

Review-Url: https://codereview.chromium.org/2168563002
Cr-Commit-Position: refs/heads/master@{#37898}

As required by the spec.

This is a variant of what I reverted in f47e7224.
It will probably still cause a regression but now it's easier to migrate (parts of)
the current implementation to C++, which is expected to make things faster again.

BUG=chromium:627729,v8:5113

Review-Url: https://codereview.chromium.org/2164923002
Cr-Commit-Position: refs/heads/master@{#37897}

This prepares for relanding:
https://codereview.chromium.org/2058033002/

All toplevel variables are visible in files including v8.gni.
This works around potential name clashes.

BUG=chromium:616034

Review-Url: https://codereview.chromium.org/2169443002
Cr-Commit-Position: refs/heads/master@{#37896}

This avoids implementation-defined signed overflow in the simulator's
AddWithCarry implementation. The implementation of AddWithCarry now uses
unsigned arithmetic exclusively.

Testing coverage is also significantly improved.

BUG=

Review-Url: https://codereview.chromium.org/2157283003
Cr-Commit-Position: refs/heads/master@{#37895}

BUG=v8:5209

Review-Url: https://codereview.chromium.org/2158393002
Cr-Commit-Position: refs/heads/master@{#37894}

Using Isolate is unsafe, because we might parse (and do scope analysis)
on a background thread.

The illegal access happens when encountering f(arguments) { ... }.

Kudos to verwaest@ for finding this bug.

R=verwaest@chromium.org, rossberg@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2158343002
Cr-Commit-Position: refs/heads/master@{#37893}

Review-Url: https://codereview.chromium.org/2162503002
Cr-Commit-Position: refs/heads/master@{#37892}

Look at the output type instead of the output representation,
when converting to tagged representation.

R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2159373004
Cr-Commit-Position: refs/heads/master@{#37891}

BUG=chromium:608617

Review-Url: https://codereview.chromium.org/2163173002
Cr-Commit-Position: refs/heads/master@{#37890}