Before this CL, the context of the parent frame was used when deoptimizing a
stub failure rather than the context value passed to the stub itself. In order
to guarantee that the right context is passed to the runtime upon stub failure,
this CL adds the context explicitly to the stub's environment that's used to
compute the failure deoptimizing translations. The context can then be extracted
during deoptimization translation to ensure that the precise context that was
passed to the stub is also passed to the runtime.

R=jarin@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/1694183003

Cr-Commit-Position: refs/heads/master@{#34030}

Support SBFX in the instruction selector for sign-extension patterns like
Sar(Shl(x, a), b), where a and b are immediate values.

BUG=

Review URL: https://codereview.chromium.org/1695293002

Cr-Commit-Position: refs/heads/master@{#34029}

Let me know if this is not the right approach

Review URL: https://codereview.chromium.org/1698483002

Cr-Commit-Position: refs/heads/master@{#34028}

Revert of Tweak type info threshold. (patchset #1 id:1 of https://codereview.chromium.org/1684093002/ )

Reason for revert:
Tanks Mandreel-latency.

Original issue's description:
> Tweak type info threshold.
>
> Let the world know (if it cares) that this is the kind of
> silliness that JS engines have to partake in if they want
> to look good on Sunspider (this should give 5% overall).
>
> Committed: https://crrev.com/4f62af4234e8ad74abd8e4cd3e492f7727efc768
> Cr-Commit-Position: refs/heads/master@{#33866}

TBR=yangguo@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.

Review URL: https://codereview.chromium.org/1699063002

Cr-Commit-Position: refs/heads/master@{#34027}

Review URL: https://codereview.chromium.org/1700923002

Cr-Commit-Position: refs/heads/master@{#34026}

Before this fix, we always ended up calling Runtime_LoadPropertyWithInterceptor, which caused the performance regression reported in http://crbug.com/585764.

BUG=585764
LOG=y

Review URL: https://codereview.chromium.org/1699913002

Cr-Commit-Position: refs/heads/master@{#34025}

BUG=

Review URL: https://codereview.chromium.org/1702443002

Cr-Commit-Position: refs/heads/master@{#34024}

This CL improves running our internal benchmarks locally by adding the
--pretty option to tools/run_perf.py. With the flag enabled we print
the run-time of each benchmark directly and avoid the json output at
the end.

NOTRY=true

Review URL: https://codereview.chromium.org/1681283004

Cr-Commit-Position: refs/heads/master@{#34023}

EnsureJSArrayWithWritableFastElements

Having several handles pointing to the backing store of an array that gets
left-trimmed might cause the gc to start marking a stale-handle still pointing
to the old backing-store start. By introducing a separate handle scope for
EnsureJSArrayWithWritableFastElements we avoid this issue. Additionally a
SLOW_DCHECK in Heap::LeftTrimFixedArray ensurse that there are no more than one
active handle pointing to the backing store.

BUG=chr:585787
LOG=n

Review URL: https://codereview.chromium.org/1699733003

Cr-Commit-Position: refs/heads/master@{#34022}

BUG=chromium:587026
LOG=n

Review URL: https://codereview.chromium.org/1698983002

Cr-Commit-Position: refs/heads/master@{#34021}

The LazyBailout operator (modelled as a nop-call) was introduced for
placing a deoptimization point into exception handlers. Now that we are
no longer re-entering lazy deoptimized code, the support can be removed.

R=jarin@chromium.org
BUG=v8:4195
LOG=n

Review URL: https://codereview.chromium.org/1697503002

Cr-Commit-Position: refs/heads/master@{#34020}

Revert of [turbofan] Combine GenericLoweringPhase and ChangeLoweringPhase. (patchset #1 id:1 of https://codereview.chromium.org/1697133002/ )

Reason for revert:
Seems to tank stuff.

Original issue's description:
> [turbofan] Combine GenericLoweringPhase and ChangeLoweringPhase.
>
> There's no need to use a dedicated ChangeLoweringPhase before we go to
> GenericLoweringPhase; instead that change lowering (which is really
> simplified lowering by now) should run together with generic lowering.
>
> R=jarin@chromium.org
>
> Committed: https://crrev.com/0835ed9caf44427755065eb45f9187678ec9844c
> Cr-Commit-Position: refs/heads/master@{#34008}

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

Review URL: https://codereview.chromium.org/1698273002

Cr-Commit-Position: refs/heads/master@{#34019}

BUG=

Review URL: https://codereview.chromium.org/1700903002

Cr-Commit-Position: refs/heads/master@{#34018}

Revert of [tools] add --pretty switch to run_perf.py (patchset #7 id:120001 of https://codereview.chromium.org/1681283004/ )

Reason for revert:
[Sheriff] Breaks android runs. Will look later why.

Original issue's description:
> [tools] add --pretty switch to run_perf.py
>
> This CL improves running our internal benchmarks locally by adding the
> --pretty option to tools/run_perf.py. With the flag enabled we print
> the run-time of each benchmark directly and avoid the json output at
> the end.
>
> NOTRY=true
>
> Committed: https://crrev.com/83f69507ab1b9380b56758b747d4f3fabc849e49
> Cr-Commit-Position: refs/heads/master@{#33981}

TBR=cbruni@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/1696293002

Cr-Commit-Position: refs/heads/master@{#34017}

Fixes a bug in Ignition on Arm64 where lr gets trashed in StaContextSlot
which causes the stack walker to get confused and crash.

BUG=v8:4680
LOG=N

Review URL: https://codereview.chromium.org/1694263002

Cr-Commit-Position: refs/heads/master@{#34016}

This was actually only necessary for dealing with %_Arguments and
%_ArgumentsLength in Crankshaft, which have been removed recently,
so there's no need to keep this piece of awesomeness around any
longer.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1695193003

Cr-Commit-Position: refs/heads/master@{#34015}

This functionality is useful for stubs that need to walk the stack. The new
machine operator, LoadParentFramePointer dosn't force the currently compiling
method to have a frame in contrast to LoadFramePointer. Instead, it adapts
accordingly when frame elision is possible, making efficient stack walks
possible without incurring a performance penalty for small stubs that can
benefit from frame elision.

R=bmeurer@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/1695313002

Cr-Commit-Position: refs/heads/master@{#34014}

BUG=

Review URL: https://codereview.chromium.org/1697283002

Cr-Commit-Position: refs/heads/master@{#34013}

  port 4ff159bd(r33880)

  original commit message:
  Add dedicated %LoadLookupSlot, %LoadLookupSlotInsideTypeof,
  %LoadLookupSlotForCall, %StoreLookupSlot_Sloppy and
  %StoreLookupSlot_Strict runtime entry points and use them
  appropriately in the various compilers. This way we can
  finally drop the machine operators from the JS graph level
  completely in TurboFan.

  Also drop the funky JSLoadDynamic operator from TurboFan,
  which was by now just a small wrapper around the runtime
  call to %LoadLookupSlot.

BUG=

Review URL: https://codereview.chromium.org/1694343002

Cr-Commit-Position: refs/heads/master@{#34012}

  port d1c28849(r33873)

  original commit message:
  Moves InterpreterAssembler out of the compiler directory and into the
  interpreter directory. Makes InterpreterAssembler as subclass of
  CodeStubAssembler.

  As part of this change, the special bytecode dispatch linkage type
  is removed and instead we use a InterfaceDispatchDescriptor and
  a normal CodeStub linkage type.

  Removes a bunch of duplicated logic in InterpreterAssembler and
  instead uses the CodeStubAssembler logic. Refactors Interpreter
  with these changes.

  Modifies CodeStubAssembler to add the extra operations required
  by the Interpreter (extra call types, raw memory access and some extra
  binary ops). Also adds the ability for subclasses to add extra
  prologue and epilogue operations around calls, which is required
  for the Interpreter.

BUG=

Review URL: https://codereview.chromium.org/1696263002

Cr-Commit-Position: refs/heads/master@{#34011}

Rolling v8/tools/clang to 7a1ebdd9ae15490c88e87bf9b34417c318fe1986

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

Review URL: https://codereview.chromium.org/1702543002

Cr-Commit-Position: refs/heads/master@{#34010}

BUG= https://code.google.com/p/v8/issues/detail?id=4203
TEST=manual
R=titzer@chromium.org,aseemgarg@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/1697723002

Cr-Commit-Position: refs/heads/master@{#34009}

There's no need to use a dedicated ChangeLoweringPhase before we go to
GenericLoweringPhase; instead that change lowering (which is really
simplified lowering by now) should run together with generic lowering.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1697133002

Cr-Commit-Position: refs/heads/master@{#34008}

This avoids quite expensive computation further downstream.

Review URL: https://codereview.chromium.org/1697173002

Cr-Commit-Position: refs/heads/master@{#34007}

Port 4eff883b
     c72b49bd

Original commit message:
    Ideally we would not need the StoreWriteBarrier instructions at all,
    but represent the RecordWrite functionality as machine subgraph, but
    that'll take some time to get there. In the mean time we can have a
    shorter instruction sequence by recognizing immediate indices here.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1695333002

Cr-Commit-Position: refs/heads/master@{#34006}

Port e0129d0f

Original commit message:
    Turn the fast case of ArgumentsAccessStub into a new stub
    FastNewSloppyArgumentsStub, which is similar to the existing
    FastNewStrictArgumentsStub, although not polished yet, and the slow
    case always went to the runtime anyway, so we can just directly emit
    a runtime call there.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1699923002

Cr-Commit-Position: refs/heads/master@{#34005}

Port 0d59772b

Original commit message:
    for the special case where the same register is used as both left and
    right input.

R=jkummerow@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1698903002

Cr-Commit-Position: refs/heads/master@{#34004}

Port 09d84535

Original commit message:
The FastNewStrictArgumentsStub is very similar to the recently added
FastNewRestParameterStub, it's actually almost a copy of it, except that
it doesn't have the fast case we have for the empty rest parameter. This
patch improves strict arguments in TurboFan and fullcodegen by up to 10x
compared to the previous version.

Also introduce proper JSSloppyArgumentsObject and JSStrictArgumentsObject
for the in-object properties instead of having them as constants in the
Heap class.

Drive-by-fix: Use this stub and the FastNewRestParameterStub in the
interpreter to avoid the runtime call overhead for strict arguments
and rest parameter creation.

BUG=

Review URL: https://codereview.chromium.org/1698173002

Cr-Commit-Position: refs/heads/master@{#34003}

V8 tracks already most useful information, but lacks proper tracing scopes
that make it possible to distinguish certain events from each other.
- add trace-scope to track lazy-parsing due to optimization
- add trace-scope to track code optimization

BUG=

Review URL: https://codereview.chromium.org/1661883003

Cr-Commit-Position: refs/heads/master@{#34002}

The GraphTrimmer should not ever see a dead node, except for the roots
that are explicitly fed into it. To defend against this, turn the
condition into a DCHECK.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1698883003

Cr-Commit-Position: refs/heads/master@{#34001}

Eventually compiler.h might need to depend on the Pipeline to manage its
life cycle for concurrent recompilation, so we should not have the
cyclic include dependency here.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1698113002

Cr-Commit-Position: refs/heads/master@{#34000}

R=ahaas@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1698133002

Cr-Commit-Position: refs/heads/master@{#33999}

Harvesting maps from the stub cache for megamorphic ICs is both slow
(linear in the size of the stub cache) and imprecise (as it finds all
maps that have a cached handler for the given property name).
In the canonical megamorphic situation, this type feedback is useless
anyway. The interesting case is when we can filter it down to a single
map; however in these cases it is often possible to derive this map
just by looking at the HGraph, which is both faster and more reliable.

Review URL: https://codereview.chromium.org/1669213003

Cr-Commit-Position: refs/heads/master@{#33998}

Now the tool produces a far more readable output format, which bears a
lot of resemblance to YAML. In fact, the output should be machine
parseable as such, one document per testcase. However, the output format
may be subject to changes in future, so don't rely on this property.

In general, the output format has been optimized for producing a meaningful
textual diff, while keeping a decent readability as well. Therefore, not
everything is as compact as it could be, e.g. for an empty const pool we get:

    constant pool: [
    ]

instead of:

    constant pool: []

Also, trailing commas are always inserted in lists.

Additionally, now the tool accepts its output format as input. When
operating in this mode, all the snippets are extracted, processed and
the output is then emitted as usual. If nothing has changed, the output
should match the input. This is very useful for catching bugs in the
bytecode generation by running a textual diff against a known-good file.

The core (namely bytecode-expectations.cc) has been extracted from the
original cc file, which provides the utility as usual. The definitions
in the matching header of the library have been moved into the
v8::internal::interpreter namespace.

The library exposes a class ExpectationPrinter, with a method
PrintExpectation, which takes a test snippet as input, and writes the
formatted expectation to the supplied stream. One might then use a
std::stringstream to retrieve the results as a string and run it through
a diff utility.

BUG=v8:4280
LOG=N

Review URL: https://codereview.chromium.org/1688383003

Cr-Commit-Position: refs/heads/master@{#33997}

for the special case where the same register is used as both left and
right input.

Review URL: https://codereview.chromium.org/1695283002

Cr-Commit-Position: refs/heads/master@{#33996}

By not calling ReloadPropertyInformation, we avoid expensive descriptor array lookup.

BUG=

Review URL: https://codereview.chromium.org/1697153002

Cr-Commit-Position: refs/heads/master@{#33995}

This is effectively a port of 4eff883b (r27731).

BUG=

Review URL: https://codereview.chromium.org/1692253002

Cr-Commit-Position: refs/heads/master@{#33994}

Passing floating point params to/from C has never quite worked correctly,
but we've never enforced the restriction early in the CallDescriptor
creation process because of unittests. Fix unittests to make their own
simple call descriptors and not rely on the C ones.

R=bmeurer@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1701593003

Cr-Commit-Position: refs/heads/master@{#33993}

This creates an isolate with the v8-side valgrind wrapper and
the valgrind binaries from third_party. It's dynamically
checked if the directories are present.

Follow up after https://codereview.chromium.org/1585093002/
and https://codereview.chromium.org/1583933006/

BUG=chromium:535160
LOG=n

Review URL: https://codereview.chromium.org/1700673002

Cr-Commit-Position: refs/heads/master@{#33992}

Properly type String.prototype.concat, String.prototype.charCodeAt,
and String.prototype.toLowerCase/toUpperCase in TurboFan. Also assign
better type to %_StringCharFromCode.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1701673002

Cr-Commit-Position: refs/heads/master@{#33991}