Before this change, we attributed samples for the top-most interpreter frame to the second-topmost frame if we were in a bytecode handler with elided frame. With this change we try to detect that we are in a handler without a frame. If we are, we do not drop the topmost frame.

For example, consider the program

function inner() {
  var s = 0;
  for (var i = 0; i < 100000; i++) {
    s += i * i;
  }
  return s;
}

function trivial() {
  return inner();
}

for (var i = 0; i < 2000; i++) {
  trivial();
}

Before this change, d8 --prof --ignition --nocrankshaft and linux-tick-processor would produce:

  [JavaScript]:
   ticks  total  nonlib   name
   4885   83.4%   83.5%  Function: ~trivial a.js:15:17
    759   13.0%   13.0%  Function: ~inner a.js:7:15

After this change, we get

 [JavaScript]:
   ticks  total  nonlib   name
   5486   95.9%   96.2%  Function: ~inner a.js:7:15
      4    0.1%    0.1%  Function: ~trivial a.js:15:17

Review-Url: https://codereview.chromium.org/2667253004
Cr-Commit-Position: refs/heads/master@{#42894}

R=jgruber@chromium.org
BUG=v8:5530

Review-Url: https://codereview.chromium.org/2670823002
Cr-Commit-Position: refs/heads/master@{#42893}

R=mstarzinger@chromium.org

Review-Url: https://codereview.chromium.org/2650193002
Cr-Commit-Position: refs/heads/master@{#42892}

The operator in question does not call arbitrary JavaSciprt, nor throw,
nor trigger a lazy deoptimization. Nodes hence do not need a frame-state
representing the "after" state of the operation.

R=bmeurer@chromium.org

Review-Url: https://codereview.chromium.org/2672763002
Cr-Commit-Position: refs/heads/master@{#42891}

We don't need Code::CALL_IC for anything now that the CallICStub is
migrated and no longer hooks into the traditional IC system.

R=yangguo@chromium.org
BUG=v8:5049

Review-Url: https://codereview.chromium.org/2669193002
Cr-Commit-Position: refs/heads/master@{#42890}

Port the Call feedback machinery from the interpreter to the CallICStub
as second step to unify the feedback collection. This removes a lot of
hand-written native code, and makes the runtime miss handler obsolete.
The next step will be to use the CallICStub from the interpreter as
well.

Drive-by-fix: Adjust CallIC/CallICTrampoline descriptors names.

R=mvstanton@chromium.org
BUG=v8:5049

Review-Url: https://codereview.chromium.org/2670843002
Cr-Commit-Position: refs/heads/master@{#42889}

R=machenbach@chromium.org
BUG=v8:5920
NOTRY=true

Review-Url: https://codereview.chromium.org/2671713002
Cr-Commit-Position: refs/heads/master@{#42888}

R=bmeurer@chromium.org

Review-Url: https://codereview.chromium.org/2675673002
Cr-Commit-Position: refs/heads/master@{#42887}

R=jgruber@chromium.org

Review-Url: https://codereview.chromium.org/2671703002
Cr-Commit-Position: refs/heads/master@{#42886}

This behavior was recently changed. Turns out that for some usage patterns
at least, populating the stub cache is significantly faster overall.

BUG=chromium:684428

Review-Url: https://codereview.chromium.org/2674653002
Cr-Commit-Position: refs/heads/master@{#42885}

This adds optional multi-architecture builds, allowing to compile
x86 and x64 in one build. The correctness fuzzer can be configured to
compare the two executables, e.g. to compare x86 to x64 run the
launcher with: --second-d8=clang_x86/d8 in an x64 build.

Configuring the executable's architecture is now simplified and
inferred from the gn build configuration.

Building for clusterfuzz has now a new canonical target that can be
used by the infrastructure (defaults to d8).

The clusterfuzz release builder is now defined to compile
multi-arch builds, which will have an effect as soon as the
infrastructure refers to the new clusterfuzz target.

BUG=chromium:673246
NOTRY=true
TBR=mstarzinger,jarin

Review-Url: https://codereview.chromium.org/2649133010
Cr-Commit-Position: refs/heads/master@{#42884}

BUG=

Review-Url: https://codereview.chromium.org/2663803002
Cr-Original-Commit-Position: refs/heads/master@{#42881}
Committed: https://chromium.googlesource.com/v8/v8/+/65ad1e35d9a97c1126a55cc9d3014598fd224259
Review-Url: https://codereview.chromium.org/2663803002
Cr-Commit-Position: refs/heads/master@{#42883}

Revert of [string] Migrate String.prototype.{split,replace} to TF (patchset #12 id:220001 of https://codereview.chromium.org/2663803002/ )

Reason for revert:
Breaks win64 debug:
https://build.chromium.org/p/client.v8/builders/V8%20Win64%20-%20debug/builds/14967

Original issue's description:
> [string] Migrate String.prototype.{split,replace} to TF
>
> BUG=
>
> Review-Url: https://codereview.chromium.org/2663803002
> Cr-Commit-Position: refs/heads/master@{#42881}
> Committed: https://chromium.googlesource.com/v8/v8/+/65ad1e35d9a97c1126a55cc9d3014598fd224259

TBR=bmeurer@chromium.org,ishell@chromium.org,yangguo@chromium.org,jgruber@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/2671673003
Cr-Commit-Position: refs/heads/master@{#42882}

BUG=

Review-Url: https://codereview.chromium.org/2663803002
Cr-Commit-Position: refs/heads/master@{#42881}

First discovery by the names section fuzzer I think. During the decoding
of the names of locals only ok() of the outer decoder was checked, not
the ok() of the actual names section decoder.

R=tizer@chromium.org
BUG=chromium:684855

Review-Url: https://codereview.chromium.org/2648383007
Cr-Commit-Position: refs/heads/master@{#42880}

The CallIC is already not a traditional IC in the V8 sense, so it
doesn't make sense to integrate with the traditional IC machinery.
The plan is to migrate it away completely from the IC world and use
the code that is already available in the interpreter instead.

R=yangguo@chromium.org
BUG=v8:5049

Review-Url: https://codereview.chromium.org/2676543002
Cr-Commit-Position: refs/heads/master@{#42879}

- Remove obsolete BreakLocatorType.
- Perform PrepareStepOnThrow after OnException event, in case stepping
  was scheduled in the exception event.
- Use frame count instead of frame pointer for stepping. Frame pointer
  is not reliable due to possible deopts.
- Consistently check for inlined functions in inlined frames.
- Use SharedFunctionInfo in FloodWithOneshot and EnsureDebugInfo.

R=jgruber@chromium.org
BUG=v8:5901

Review-Url: https://codereview.chromium.org/2664793002
Cr-Commit-Position: refs/heads/master@{#42878}

First step to unify CallIC in Ignition, TurboFan/Crankshaft and
fullcodegen.

R=yangguo@chromium.org
BUG=v8:5267

Review-Url: https://codereview.chromium.org/2669123002
Cr-Commit-Position: refs/heads/master@{#42877}

Rename the CallIC factory method to CallICTrampoline and the
CallICInOptimizedCode to CallIC to match the naming of the
stubs and better reflect their functionality.

R=yangguo@chromium.org

Review-Url: https://codereview.chromium.org/2670073002
Cr-Commit-Position: refs/heads/master@{#42876}

This introduces additional verification logic to ensure that the
condition passed to Branch/Select operators is always of type
Boolean.

CQ_INCLUDE_TRYBOTS=master.tryserver.v8:v8_win64_dbg
TBR=jarin@chromium.org
BUG=v8:5267

Review-Url: https://codereview.chromium.org/2672713002
Cr-Commit-Position: refs/heads/master@{#42875}

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/47e07d6..7a418db

Rolling v8/third_party/catapult: https://chromium.googlesource.com/external/github.com/catapult-project/catapult/+log/4ee31ea..fc2f450

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

Review-Url: https://codereview.chromium.org/2671563003
Cr-Commit-Position: refs/heads/master@{#42874}

Remove the cases that deal with a top pointer that is reset. We should always
be in a sane state wrt. top and age mark. Also add more DCHECKs.

BUG=chromium:672678

Review-Url: https://codereview.chromium.org/2674493002
Cr-Commit-Position: refs/heads/master@{#42873}

This avoids the need to pull in the UTF-8 encoding code from the public API,
and allows it to take advantage of any supported way that i::String can be
encoded (one- or two-byte).

Backward compatibility is maintained, but this is the behavior beginning
with this version.

BUG=chromium:686159

Review-Url: https://codereview.chromium.org/2665653004
Cr-Commit-Position: refs/heads/master@{#42872}

Also if the count is not specified, it should wake all waiters.

BUG=v8:4777

Review-Url: https://codereview.chromium.org/2659083004
Cr-Commit-Position: refs/heads/master@{#42871}

- Uses macros to reduce code duplication.
- Uses calls to VisitRO, VisitRR, VisitRROFloat, and VisitFloatUnop to
  reduce code bloat.

LOG=N
BUG=v8:4124

Review-Url: https://codereview.chromium.org/2669683002
Cr-Original-Commit-Position: refs/heads/master@{#42830}
Committed: https://chromium.googlesource.com/v8/v8/+/5e6eb91d0d66c9a118f1cc576accb649a17c5a9d
Review-Url: https://codereview.chromium.org/2669683002
Cr-Commit-Position: refs/heads/master@{#42870}

R=bjaideep@ca.ibm.com, joransiu@ca.ibm.com
BUG=

Review-Url: https://codereview.chromium.org/2667203002
Cr-Commit-Position: refs/heads/master@{#42869}

R=bjaideep@ca.ibm.com, joransiu@ca.ibm.com
BUG=

Review-Url: https://codereview.chromium.org/2668763005
Cr-Commit-Position: refs/heads/master@{#42868}

Even though the elements kind is FAST_DOUBLE_ELEMENTS, if length is zero
the isolate's empty_fixed_array is used. It's illegal to cast this to
FixedDoubleArray, so we avoid the cast.

BUG=chromium:686479

Review-Url: https://codereview.chromium.org/2665313003
Cr-Commit-Position: refs/heads/master@{#42867}

BUG=

Review-Url: https://codereview.chromium.org/2672503002
Cr-Commit-Position: refs/heads/master@{#42866}

- Adds vqadd.s/u, vqsub.s/u for all integer lane sizes.
- Refactors disassembler and simulator, using switches instead
of long if-else chains.

LOG=N
BUG=v8:4124

Review-Url: https://codereview.chromium.org/2649323012
Cr-Commit-Position: refs/heads/master@{#42865}

R=joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Review-Url: https://codereview.chromium.org/2668303002
Cr-Commit-Position: refs/heads/master@{#42864}

This allows support for tagged representations of index/loop variables which
asserted in BuildFastFixedArrayForEach's call to Increment up to this point.

Review-Url: https://codereview.chromium.org/2665143002
Cr-Commit-Position: refs/heads/master@{#42863}

- Uses macros to reduce code duplication.
- Uses calls to VisitRO and VisitRR to reduce code bloat.

LOG=N
BUG=v8:4124

Review-Url: https://codereview.chromium.org/2668753004
Cr-Original-Commit-Position: refs/heads/master@{#42828}
Committed: https://chromium.googlesource.com/v8/v8/+/e8e2e3c826d42490f809e1c45750bbb438b60d8c
Review-Url: https://codereview.chromium.org/2668753004
Cr-Commit-Position: refs/heads/master@{#42862}

The hoist_scope member of DeclarationDescriptor was only used to pass the function
scope for declaration of parameters containing sloppy evals, for example:

  function f(x = eval("var y")) { }

In cases like this, "x" is declared in the function scope but "y" is declared in an inner scope.
Rather than passing the function scope as "hoist_scope", we simply ask for the outer_scope()
of the inner scope as needed in PatternRewriter.

This reduces the cognitive overhead of understanding what a DeclarationDescriptor has; for
example, it removes some dead code from the PreParser which never has to deal
with a situation like the example above.

Review-Url: https://codereview.chromium.org/2662183002
Cr-Commit-Position: refs/heads/master@{#42861}

The int64-lowering only lowered store instructions with a word64 store
representation. For all other stores the default lowering applied. The
default lowering replaces all input nodes with both their replacement
nodes, which can change the number of input nodes of the lowered node.

In WebAssembly there exist stores which take an I64 input and store it
with a different representation, e.g. I32. In TurboFan this translates
to a store node with word32 store representation and a word64 value
input. The default lowering replaces the word64 value input to become
two word32 value inputs, which makes the number of inputs of the store
node invalid. This CL discards the high word replacement of the value
input so that the number of input nodes of a store node does not change
in the default lowering.

R=titzer@chromium.org
CC=rossberg@chromium.org

BUG=

Review-Url: https://codereview.chromium.org/2668023004
Cr-Commit-Position: refs/heads/master@{#42860}

This is a step towards encoding all the necessary information in
the feedback slot kind instead of storing it in the IC dispatcher's
code object flags.

BUG=v8:5849, v8:5917

Review-Url: https://codereview.chromium.org/2662113005
Cr-Commit-Position: refs/heads/master@{#42859}

Port 87d309da

Original Commit Message:

    This is the first step to reduce the size of the out-of-line code of
    TrapIf. Instead of passing the context to the runtime call as a
    parameter, we pass Smi::kZero to the runtime call and then get the
    actual context from the WasmFrame on the stack.

R=ahaas@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=v8:5908
LOG=N

Review-Url: https://codereview.chromium.org/2661363003
Cr-Commit-Position: refs/heads/master@{#42858}

BUG=v8:5294

Review-Url: https://codereview.chromium.org/2662393004
Cr-Commit-Position: refs/heads/master@{#42857}

R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2667123002
Cr-Commit-Position: refs/heads/master@{#42856}

Using .caller, one can get access to the internal function that invokes the
handler passed to Promise.prototype.then.  This internal function is a TF
builtin that was set up as non-native and without an argument adaptor.  As a
consequence of this, when accessing .arguments on it, the frame-walking logic in
the .arguments accessor thinks the number of arguments is -1 and we try to
allocate an array of size -1.

This CL marks the builtin function as native (making its .arguments be null),
along with a few others that may have been incorrect in the same way.

BUG=chromium:682349

Review-Url: https://codereview.chromium.org/2672453002
Cr-Commit-Position: refs/heads/master@{#42855}