Commit Graph

13805 Commits

Author SHA1 Message Date
bmeurer@chromium.org
2ee5aa951c Fix missing type feedback check for Generic*String addition.
TEST=mjsunit/regress/regress-crbug-318671
BUG=318671
LOG=y
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/67473007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17772 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-15 09:13:36 +00:00
yurys@chromium.org
1c24c44e22 Mark cctest/test-alloc/CodeRange as flaky on Windows
BUG=v8:3005
LOG=N
R=machenbach@chromium.org

Review URL: https://codereview.chromium.org/65833003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17771 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-15 09:10:44 +00:00
rafaelw@chromium.org
bdf78a7ad3 Reland [Object.observe] Don't force normalization of elements for observed objects
Original Issue: https://codereview.chromium.org/29353003/

Note that this version of the patch includes logic for bailing out of compiled ArrayPush/ArrayPop calls if the array is observed (see stub-cache-*)

R=danno@chromium.org
BUG=v8:2946
LOG=N

Review URL: https://codereview.chromium.org/68343016

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17769 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 21:47:39 +00:00
rafaelw@chromium.org
25b450b2b7 Revert "Improvements in positions handling in optimizing compiler." (r17765)
Original issue: https://codereview.chromium.org/49203002/

TBR=vegorov

Review URL: https://codereview.chromium.org/63343003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17768 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 21:45:01 +00:00
plind44@gmail.com
f923ff3cab MIPS: Also support smi in load-ICs.
Port r17756 (12e5896)

BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/72603006

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17767 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 21:12:22 +00:00
vegorov@chromium.org
9d440ac4c0 Improvements in positions handling in optimizing compiler.
- When building binary arithmetic op and comparison restore source position of the operation itself before building operation itself after it was changed by building operands. This ensures that position recorded for operation points to the operation token instead of pointing to the rightmost operand;

- Add support for recording operands' positions and use these positions when inserting HChange instructions;

- When generating hydrogen.cfg emit H-instruction position as BCI (previously 0 was emitted), additionally on every lithium instruction emit annotation pointing to corresponding hydrogen-instruction. This allows to easily reach from deopt_id to lithium instruction and from it to hydrogen instruction and source position.

BUG=
R=danno@chromium.org

Review URL: https://codereview.chromium.org/49203002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17765 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 21:00:27 +00:00
rafaelw@chromium.org
5e8e9cd408 Fix GCMole warning
R=adamk@chromium.org
TBR=mstarzinger@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/73123002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17763 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 20:51:18 +00:00
plind44@gmail.com
ee575e8f88 MIPS: Handle all object types (minus smi) in load/store ICs.
Port r17755 (bfef904)

BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/72983002

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17762 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 20:35:12 +00:00
plind44@gmail.com
488a0be3ad MIPS: Remove unused LoadNumber* from macro assembler.
Port r17748 (595bed6)

BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/70233011

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17760 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 18:48:54 +00:00
plind44@gmail.com
166799c2c4 MIPS: Inline zero argument array constructor.
Port r17741 (fe14ef8)

Original commit message:
patch from issue 54583003 (dependent code).

Zero arguments - very easy

1 argument - three special cases:
a) If length is a constant in valid array length range,
no need to check it at runtime.
b) respect DoNotInline feedback on the AllocationSite for
cases that the argument is not a smi or is an integer
with a length that should create a dictionary.
c) if kind feedback is non-holey, and length is non-constant,
we'd have to generate a lot of code to be correct.
Don't inline this case.

N arguments - one special case:
a) If a deopt ever occurs because an input argument isn't
compatible with the elements kind, then set the
DoNotInline flag.

BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/72893003

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17759 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 18:44:05 +00:00
rafaelw@chromium.org
161cc3cd2a Handlify JSObject::SetElement & brethren
Because SetElement & co are interdependent, this patch handlfies all of JSObject::
-SetElement
-SetFastElement
-SetDictionaryElement
-SetFastDoubleElement
-SetElementWithInterceptor
-SetElementWithoutInterceptor
-SetElementWithCallbackSetterInPrototype

R=mstarzinger@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/66803002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17757 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 17:30:48 +00:00
verwaest@chromium.org
6befb8d5cd Also support smi in load-ICs.
BUG=
R=ulan@chromium.org

Review URL: https://chromiumcodereview.appspot.com/68523009

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17756 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 16:37:36 +00:00
verwaest@chromium.org
93f2ed48d9 Handle all object types (minus smi) in load/store ICs
R=ulan@chromium.org

Review URL: https://chromiumcodereview.appspot.com/62953007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17755 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 16:25:31 +00:00
mstarzinger@chromium.org
883a5c803c Remove obsolete distance switch in SubStringStub::Generate.
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/72073004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17754 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 16:03:55 +00:00
ulan@chromium.org
31493412c4 Do not update survival rate if the new space size is zero.
BUG=v8:2333
LOG=N
R=hpayer@chromium.org

Review URL: https://chromiumcodereview.appspot.com/48443002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17753 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 15:25:21 +00:00
mstarzinger@chromium.org
9f4591c368 Add ability to disable inline bump-pointer allocation.
R=ulan@chromium.org, yurys@chromium.org
TEST=cctest/test-heap/DisableInlineAllocation

Review URL: https://codereview.chromium.org/69953023

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17752 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 15:14:37 +00:00
machenbach@chromium.org
eef8694a7e [Sheriff] Revert "Add support for keyed-call on arrays of fast elements"
This reverts commit r17746 for breaking layout tests.

TBR=verwaest@chromium.org
BUG=

Review URL: https://codereview.chromium.org/72753002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17751 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 15:00:13 +00:00
machenbach@chromium.org
a2c722a7b3 Fixed blocking dcommit in push-to-trunk script.
BUG=
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/72703002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17750 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 14:50:17 +00:00
machenbach@chromium.org
901e4f60c5 Add ChangeLog presubmit check.
LOG=
BUG=
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/61733023

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17749 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 14:49:07 +00:00
yangguo@chromium.org
fe0987c98d Remove unused LoadNumber* from ARM macro assembler.
R=ulan@chromium.org
BUG=

Review URL: https://codereview.chromium.org/70093002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17748 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 14:15:52 +00:00
yangguo@chromium.org
34c830c086 Fix duplicate check in DependentCode::Insert.
R=ulan@chromium.org
BUG=318454

Review URL: https://codereview.chromium.org/71653008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17747 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 14:14:11 +00:00
verwaest@chromium.org
607a175cbc Add support for keyed-call on arrays of fast elements
R=danno@chromium.org

Review URL: https://chromiumcodereview.appspot.com/23537067

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17746 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 13:46:18 +00:00
yurys@chromium.org
c7b1b79e4d This is the exact copy of r17365 which was reverted in r17488 due to memory corruption. The root cause for the memory corruption - missing check for bump pointer limit before storing filler map must be addressed in r17626 where allocation hooks were removed from the generated code and left only in the runtime.
This is initial implementation of allocation profiler.

Whenever new object allocation is reported to the HeapProfiler and allocation tracking is on we will capture current stack trace, add it to the collection of the allocation traces (a tree) and attribute the allocated size to the top JS function on the stack.

Format of serialized heap snapshot is extended to include information about recorded allocation stack traces.

This patch is r17301 plus a fix for the test crash in debug mode. The test crashed because we were traversing stack trace when just allocated object wasn't completely configured, in particular the map pointer was incorrect. Invalid Map pointer broke heap iteration required to find Code object for a given pc during stack traversal. The solution is to insert free space filler in the newly allocated block just before collecting stack trace.

BUG=chromium:277984,v8:2949
R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/61893031

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17742 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 12:13:26 +00:00
mvstanton@chromium.org
3cf157b43b Inline zero argument array constructor.
patch from issue 54583003 (dependent code).

Zero arguments - very easy

1 argument - three special cases:
  a) If length is a constant in valid array length range,
     no need to check it at runtime.
  b) respect DoNotInline feedback on the AllocationSite for
     cases that the argument is not a smi or is an integer
     with a length that should create a dictionary.
  c) if kind feedback is non-holey, and length is non-constant,
     we'd have to generate a lot of code to be correct.
     Don't inline this case.

N arguments - one special case:
  a) If a deopt ever occurs because an input argument isn't
     compatible with the elements kind, then set the
     DoNotInline flag.

BUG=
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/55933002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17741 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 12:05:09 +00:00
verwaest@chromium.org
f6af4e19f5 Avoid integer overflow in CopyMap.
R=jkummerow@chromium.org

Review URL: https://chromiumcodereview.appspot.com/63173023

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17740 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 11:56:03 +00:00
dslomov@chromium.org
230d5bf3af Runtime CHECK for overflow in NewTypedArray.
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/62713006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17739 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 11:52:24 +00:00
dslomov@chromium.org
aefa2a2161 Reland "Harden NumberToSize against overflows."
The callers to NumberToSize are supposed to validate the number, but
this adds a last line of defense.

TBR=jkummerow@chromium.org, ulan@chromium.org

Review URL: https://codereview.chromium.org/61733021

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17737 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 11:40:32 +00:00
jochen@chromium.org
c6705f5e40 Deprecate v8::Locker::{Start,Stop}Preemption
BUG=v8:3004
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/63173022

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17736 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 11:37:32 +00:00
dslomov@chromium.org
fe70e2d694 Revert "Harden NumberToSize against overflows."
This reverts commit r17733 for breaking Linux build.

TBR=jkummerow@chromium.org
BUG=

Review URL: https://codereview.chromium.org/69243005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17734 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 11:19:30 +00:00
dslomov@chromium.org
10138add57 Harden NumberToSize against overflows.
The callers to NumberToSize are supposed to validate the number, but
this adds a last line of defense.

R=jkummerow@chromium.org, ulan@chromium.org

Review URL: https://codereview.chromium.org/72323003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17733 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 11:14:06 +00:00
machenbach@chromium.org
37dcc41d29 Prepare push to trunk. Now working on version 3.23.5.
R=jkummerow@chromium.org
BUG=

Review URL: https://codereview.chromium.org/72623002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17729 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 10:54:36 +00:00
yangguo@chromium.org
b1fd56dd7c Magic fix for Math.sin/cos.
It turns out that Sunspider 1.0's 3d-morph verifies that the floating
point error must start with 6.

R=jkummerow@chromium.org
BUG=

Review URL: https://codereview.chromium.org/61593008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17725 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 10:11:06 +00:00
danno@chromium.org
28ed69b8fb Fix overflow in TypedArray initialization function
BUG=chromium:319120
TEST=test/mjsunit/regress/regress-319120.js
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/61753013

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17711 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-14 06:20:48 +00:00
plind44@gmail.com
cd7a1c740a MIPS: Simplify behavior of code stubs that accept a variable number of stack arguments in addition to their parameters.
Port r17680 (cc0b972)

Original commit message:
Before, we'd add a special
variable to the environment with the value of a register with the
number of arguments. Now, that register just appears as a parameter to
the code stub.

BUG=
R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/70163006

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17710 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 18:23:42 +00:00
ulan@chromium.org
3099783743 Add a flag to lexer-shell to replicate input file.
R=verwaest@chromium.org

Review URL: https://chromiumcodereview.appspot.com/71783002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17709 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 18:16:19 +00:00
mvstanton@chromium.org
026c5507bd Make HForceRepresentation an idef.
An optimization in the array constructor wasn't firing because the code
would check for constant values, failing to find them through
intervening HForceRepresentation instructions. Repaired this site. A
follow-on CL will provide a better way of making decisions based on
constant HValues.

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/59623009

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17708 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 17:03:11 +00:00
dslomov@chromium.org
e4ddf3ca48 Remove boilerplate code in DataView getter/setter implementations
R=rossberg@chromium.org

Review URL: https://codereview.chromium.org/68503006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17704 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 16:11:36 +00:00
yangguo@chromium.org
8769c92bc9 Slight change to Math.sin approximation.
This is again to make sunspider's weird result verification happy.

R=jkummerow@chromium.org
BUG=

Review URL: https://codereview.chromium.org/61753011

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17703 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 16:10:03 +00:00
rmcilroy@chromium.org
82d7855748 Fix shared library build after r17696
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/71573002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17700 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 15:32:02 +00:00
rmcilroy@chromium.org
96b18590fd Enable physical memory argument to be passed as an argument to ConfigureResourceConstraintsForPlatform.
BUG=312241
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/68203003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17696 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 14:05:06 +00:00
ulan@chromium.org
f621f50fb2 Fix shared library build after r17692.
BUG=
R=jkummerow@chromium.org

Review URL: https://chromiumcodereview.appspot.com/70663003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17693 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 12:59:49 +00:00
ulan@chromium.org
81761f9dc6 Add lexer-shell for running lexer benchmarks.
R=jkummerow@chromium.org

Review URL: https://chromiumcodereview.appspot.com/70263003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17692 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 12:26:09 +00:00
machenbach@chromium.org
f903c0fc9a Prepare push to trunk. Now working on version 3.23.4.
R=jkummerow@chromium.org
BUG=

Review URL: https://codereview.chromium.org/71443002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17689 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 12:19:42 +00:00
rossberg@chromium.org
67edfbaef8 Fix warnings
R=yangguo@chromium.org
BUG=

Review URL: https://codereview.chromium.org/71373003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17688 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 12:18:52 +00:00
machenbach@chromium.org
cbe604f4df [Sheriff] Mark flaky webkit test.
TBR=jkummerow@chromium.org
BUG=v8:2989

Review URL: https://codereview.chromium.org/62283008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17686 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 11:09:47 +00:00
yangguo@chromium.org
7206330260 Change table size for trigonometric functions.
Sunspider verifies floating point results to the last bit, so this is to
make sure that we return the expected result.

R=jkummerow@chromium.org
BUG=

Review URL: https://codereview.chromium.org/71123003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17685 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 10:44:28 +00:00
machenbach@chromium.org
6822e027b3 [Sheriff] Mark flaky webkit test.
TBR=jkummerow@chromium.org
BUG=v8:2989

Review URL: https://codereview.chromium.org/68573003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17684 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 10:43:43 +00:00
rossberg@chromium.org
cec8383cff Provide private symbols through internal APIs
Adds a notion of private symbols, mainly intended for internal use, especially, self-hosting of built-in types that would otherwise require new C++ classes.

On the JS side (i.e., in built-ins), private properties can be created and accessed through a set of macros:

  NEW_PRIVATE(print_name)
  HAS_PRIVATE(obj, sym)
  GET_PRIVATE(obj, sym)
  SET_PRIVATE(obj, sym, val)
  DELETE_PRIVATE(obj, sym)

In the V8 API, they are accessible via a new class Private, and respective HasPrivate/Get/Private/SetPrivate/DeletePrivate methods on calss Object.

These APIs are designed and restricted such that their implementation can later be replaced by whatever ES7+ will officially provide.

R=yangguo@chromium.org
BUG=

Review URL: https://codereview.chromium.org/48923002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17683 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 10:34:06 +00:00
mvstanton@chromium.org
9d6dddb9ae Simplify behavior of code stubs that accept a variable number of stack
arguments in addition to their parameters. Before, we'd add a special
variable to the environment with the value of a register with the
number of arguments. Now, that register just appears as a parameter to
the code stub.

BUG=
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/70203002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17680 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 10:07:04 +00:00
palfia@homejinni.com
93c6ba639b MIPS: Fix usage of EmitBranch in compare-minus-zero-and-branch.
Port r17669 (132efad)

BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/71003003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17675 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 02:56:30 +00:00