Port 8dad78cd

Original commit message:
This adds the basics necessary to support float32 operations in TurboFan.
The actual functionality required to detect safe float32 operations will
be added based on this later. Therefore this does not affect production
code except for some cleanup/refactoring.

In detail, this patchset contains the following features:
- Add support for float32 operations to arm, arm64, ia32 and x64
  backends.
- Add float32 machine operators.
- Add support for float32 constants to simplified lowering.
- Handle float32 representation for phis in simplified lowering.

In addition, contains the following (related) cleanups:
- Fix/unify naming of backend instructions.
- Use AVX comparisons when available.
- Extend ArchOpcodeField to 9 bits (required for arm64).
- Refactor some code duplication in instruction selectors.

BUG=v8:3589
LOG=n

Review URL: https://codereview.chromium.org/1046953004

Cr-Commit-Position: refs/heads/master@{#27531}

TEST=
BUG=

Review URL: https://codereview.chromium.org/1046873004

Cr-Commit-Position: refs/heads/master@{#27530}

The V8::IdleNotification will only return 'True' when the gc idle time handler
thinks there is no more GC which can be done. However, the gc idle task handler
can end up repeatedly making no progress (e.g., if it can't finalize a sweep)
which causes idle tasks to be repeatedly scheduled in Chrome which do nothing
but wake up Chrome. Fix this by returning Done if we can't make any progress
within an Idle Round.

BUG=chromium:470615
LOG=Y

Review URL: https://codereview.chromium.org/1042483002

Cr-Commit-Position: refs/heads/master@{#27529}

BUG=chromium:470804
LOG=Y

Review URL: https://codereview.chromium.org/1033273005

Cr-Commit-Position: refs/heads/master@{#27528}

R=machenbach@chromium.org

Review URL: https://codereview.chromium.org/1033033002

Cr-Commit-Position: refs/heads/master@{#27527}

We only report the usages when full parse is happening, i.e. only when the function that declares a legacy const is compiled. This is an approximation that is easy to implement, but still should reflect the real-world usage.

BUG=v8:3942
LOG=N

Review URL: https://codereview.chromium.org/1041863002

Cr-Commit-Position: refs/heads/master@{#27526}

Revert of [es6] Update test262 tests (patchset #4 id:60001 of https://codereview.chromium.org/1025043002/)

Reason for revert:
Bot failed to include verifyNotEnumerable function for some screwed up reason.

Original issue's description:
> [es6] Update test262 tests
>
> This updates test262 to revision d24fd10 (2015/03/11).
>
> The files moved around in the test repo and a lot of new tests are
> failing.
>
> BUG=None
> LOG=N
> R=rossberg
>
> Committed: https://crrev.com/4f2fb3835feff3663146f12be42b01a226d0065e
> Cr-Commit-Position: refs/heads/master@{#27522}

TBR=rossberg@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=None

Review URL: https://codereview.chromium.org/1047713002

Cr-Commit-Position: refs/heads/master@{#27525}

This test will fail once we optimize top-level code, because the
aforementioned intrinsic doesn't perform a NumberToUint32 conversion.

R=titzer@chromium.org
TEST=mjsunit/asm/math-clz32

Review URL: https://codereview.chromium.org/1041173002

Cr-Commit-Position: refs/heads/master@{#27524}

This prepares for re-landing crrev.com/956373002

This pulls all decision about the snapshot [no|internal|external] into one rule. Previously, this logic was in separate places and not /quite/ the same, which causes build problems.

BUG=

Review URL: https://codereview.chromium.org/1016603004

Cr-Commit-Position: refs/heads/master@{#27523}

This updates test262 to revision d24fd10 (2015/03/11).

The files moved around in the test repo and a lot of new tests are
failing.

BUG=None
LOG=N
R=rossberg

Review URL: https://codereview.chromium.org/1025043002

Cr-Commit-Position: refs/heads/master@{#27522}

Review URL: https://codereview.chromium.org/1042843002

Cr-Commit-Position: refs/heads/master@{#27521}

R=hpayer@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1040763002

Cr-Commit-Position: refs/heads/master@{#27520}

BUG=

Review URL: https://codereview.chromium.org/1034393002

Cr-Commit-Position: refs/heads/master@{#27519}

R=verwaest@chromium.org,dslomov@chromium.org

BUG=

Review URL: https://codereview.chromium.org/1038313004

Cr-Commit-Position: refs/heads/master@{#27518}

BUG=chromium:468554
LOG=n

Review URL: https://codereview.chromium.org/1034403002

Cr-Commit-Position: refs/heads/master@{#27517}

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/1040053002

Cr-Commit-Position: refs/heads/master@{#27516}

R=verwaest@chromium.org
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/1045763002

Cr-Commit-Position: refs/heads/master@{#27515}

This CL reduces the size of generated code for snapshot by 1.6%.

TEST=
BUG=

Review URL: https://codereview.chromium.org/1039283002

Cr-Commit-Position: refs/heads/master@{#27514}

A follow-up CL will implement incremental sweeping during idle time.

BUG=

Review URL: https://codereview.chromium.org/1038283003

Cr-Commit-Position: refs/heads/master@{#27513}

R=verwaest@chromium.org
BUG=v8:3976
LOG=y

Review URL: https://codereview.chromium.org/1041483004

Cr-Commit-Position: refs/heads/master@{#27512}

A bug allows JSObject literals with elements to have the elements in the
boilerplate modified.

BUG=466993
LOG=N

Review URL: https://codereview.chromium.org/1037273002

Cr-Commit-Position: refs/heads/master@{#27511}

also some drive-by handlescope fixes in api.cc

R=svenpanne@chromium.org

BUG=

Review URL: https://codereview.chromium.org/1040043002

Cr-Commit-Position: refs/heads/master@{#27510}

This adds the basics necessary to support float32 operations in TurboFan.
The actual functionality required to detect safe float32 operations will
be added based on this later. Therefore this does not affect production
code except for some cleanup/refactoring.

In detail, this patchset contains the following features:
- Add support for float32 operations to arm, arm64, ia32 and x64
  backends.
- Add float32 machine operators.
- Add support for float32 constants to simplified lowering.
- Handle float32 representation for phis in simplified lowering.

In addition, contains the following (related) cleanups:
- Fix/unify naming of backend instructions.
- Use AVX comparisons when available.
- Extend ArchOpcodeField to 9 bits (required for arm64).
- Refactor some code duplication in instruction selectors.

BUG=v8:3589
LOG=n
R=dcarney@chromium.org

Review URL: https://codereview.chromium.org/1044793002

Cr-Commit-Position: refs/heads/master@{#27509}

No compiler support for now (BTW: %_NewString, doesn't have that,
either), inline allocation will come later. Hopefully the last
intrisic to add for a StringAddStub POC...

Review URL: https://codereview.chromium.org/1041723002

Cr-Commit-Position: refs/heads/master@{#27508}

And reland "Use a slot that is located on a heap page when removing
invalid entries from the SlotsBuffer."

This reverts commits de018fbd and
d23a9f7a.

Reason for relanding: looking fine on Canary, let's get these fixes back in.

BUG=chromium:454297,chromium:470801
LOG=y
TBR=ishell@chromium.org

Review URL: https://codereview.chromium.org/1043703003

Cr-Commit-Position: refs/heads/master@{#27507}

Port 019096f8

Original commit message:

R=mbrandy@us.ibm.com

BUG=

Review URL: https://codereview.chromium.org/1036273003

Cr-Commit-Position: refs/heads/master@{#27506}

This avoid to depend on MiscField to be big enough to hold the offset/size.
This patch also remove the Arm64PokePair which is no longer used.

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/1039753002

Cr-Commit-Position: refs/heads/master@{#27505}

We do not need to step one instruction further since we do not use Jr to J
optimization anymore for mips64.

TEST=
BUG=

Review URL: https://codereview.chromium.org/1041833002

Cr-Commit-Position: refs/heads/master@{#27504}

This CL also adds useful machinery that helps triggering incremental write barriers.

BUG=chromium:469146
LOG=Y

Review URL: https://codereview.chromium.org/1039733003

Cr-Commit-Position: refs/heads/master@{#27503}

On 'debugger' statement, if anything in debugger calls 'EnsureDebugInfo'
on a function, EnsureDebugInfo would compile and substitute code without
debug break slots. This causes weird behavior later when stepping fails
to work (see added test as an example).
This fix is to make sure the debugger is prepared for breakpoints in
that case as well.

Also adds extra testing for bug 468661.

R=yangguo@chromium.org,yurys@chromium.orh
BUG=v8:3990,chromium:468661
LOG=N

Review URL: https://codereview.chromium.org/1032353002

Cr-Commit-Position: refs/heads/master@{#27502}

R=jochen@chromium.org

Review URL: https://codereview.chromium.org/1041743002

Cr-Commit-Position: refs/heads/master@{#27501}

This fixes simulated debug-mode failures in the following tests:
  mjsunit/regexp-stack-overflow
  mjsunit/regress/regress-crbug-467047

R=mbrandy@us.ibm.com

BUG=

Review URL: https://codereview.chromium.org/1035003002

Cr-Commit-Position: refs/heads/master@{#27500}

TEST=mjsunit/compiler/regress-3, osr-maze1
BUG=

Review URL: https://codereview.chromium.org/1038173003

Cr-Commit-Position: refs/heads/master@{#27499}

R=verwaest@chromium.org
BUG=466084
LOG=N

Review URL: https://codereview.chromium.org/1037213002

Cr-Commit-Position: refs/heads/master@{#27498}

Review URL: https://codereview.chromium.org/1031383002

Cr-Commit-Position: refs/heads/master@{#27497}

Convert a perf trybot JSON file into a pleasing HTML page. It can read
from standard input or via the --filename option. Examples:

  cat results.json | perf-to-html.py --title "ia32 results"
  perf-to-html.py -f results.json -t "ia32 results" -o results.html

Options:
  -h, --help            show this help message and exit
  -f FILENAME, --filename=FILENAME
                        Specifies the filename for the JSON results rather
                        than reading from stdin.
  -t TITLE, --title=TITLE
                        Optional title of the web page.
  -o OUTPUT, --output=OUTPUT
                        Write html output to this file rather than stdout.

R=machenbach@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1033603004

Cr-Commit-Position: refs/heads/master@{#27496}

Revert of [turbofan][arm64] Match fneg for -0.0 - x pattern. (patchset #1 id:1 of https://codereview.chromium.org/1013743006/)

Reason for revert:
Revert due to crash.

Original issue's description:
> [turbofan][arm64] Match fneg for -0.0 - x pattern.
>
> Note that this patch add an extra bit to the ArchOpcodeField.
>
> R=bmeurer@chromium.org
>
> Committed: https://crrev.com/fe7441225100660d01e66ce3bcaefe368f62df81
> Cr-Commit-Position: refs/heads/master@{#27494}

TBR=bmeurer@chromium.org,baptiste.afsa@arm.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1041633002

Cr-Commit-Position: refs/heads/master@{#27495}

Note that this patch add an extra bit to the ArchOpcodeField.

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/1013743006

Cr-Commit-Position: refs/heads/master@{#27494}

The current GC idle time handling heuristics are getting too complicated. Moreover, with longer idle time we are getting more full garbage collections. This CL shrinks the idle round window and reduces complexity in the case where we cause a full garbage collection.

BUG=chromium:468554
LOG=n

Review URL: https://codereview.chromium.org/1024043003

Cr-Commit-Position: refs/heads/master@{#27493}

BUG=

Review URL: https://codereview.chromium.org/1039153002

Cr-Commit-Position: refs/heads/master@{#27492}