Duplicate identifier detection must be an early syntax error in strict code,
so errors in otherwise lazily compiled functions must be caught in the
preparser.
Originally introduced in r8541 and reverted in r8542.
Now really compiles on Windows.
Review URL: http://codereview.chromium.org/7782023
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9172 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
common.gypi now contains global target defaults and is included by all .gyp files;
standalone.gypi contains definitions for stand-alone v8 builds.
This fixes d8 for the ARM simulator.
TEST=compiles and tests pass on all platforms
Review URL: http://codereview.chromium.org/7740020
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9019 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Advantage is that it's much easier to add new element types (like FAST_SMI_ELEMENTS), and that handling logic for each element kind is (more) consolidated.
Currently, only GetElementsWithReceiver uses the new encapsulation, but the goal is to move much more element functionality into the class incrementally.
BUG=none
TEST=none
Review URL: http://codereview.chromium.org/7527001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8810 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The preprocessor defines ENABLE_LOGGING_AND_PROFILING and ENABLE_VMSTATE_TRACKING has been removed as these where required to be turned on for Crankshaft to work. To re-enable reducing the binary size by leaving out heap and CPU profiler a new set of defines needs to be created.
R=ager@chromium.org
BUG=v8:1271
TEST=all
Review URL: http://codereview.chromium.org//7350014
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8622 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Generate Mach-O in-memory objects for OSX. Dump locals and parameters
for non-optimized frames.
Unfortunately, it seems like more-recent-GDB on OSX there is a little
temperamental (eg, the version from macports will be missing symbols
from gdb-integration_g when the version included in xcode will not--
and this is with --gdbjit off).
Includes some Python scripts to make dealing with V8 values in gdb more
pleasant.
Patch by Luke Zarko.
Review URL: http://codereview.chromium.org/6995161
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8483 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
- Introduce a class JSReceiver, that is a common superclass of JSObject and
JSProxy. Use JSReceiver where appropriate (probably lots of places that we
still have to migrate, but we will find those later with proxy test suite).
- Move appropriate methods to JSReceiver class (SetProperty,
GetPropertyAttribute, Get/SetPrototype, Lookup, and so on).
- Introduce new JSFunctionProxy subclass of JSProxy. Currently only a stub.
- Overhaul enum InstanceType:
* Introduce FIRST/LAST_SPEC_OBJECT_TYPE that ranges over all types that
represent JS objects, and use that consistently to check language types.
* Rename FIRST/LAST_JS_OBJECT_TYPE and FIRST/LAST_FUNCTION_CLASS_TYPE
to FIRST/LAST_[NON]CALLABLE_SPEC_OBJECT_TYPE for clarity.
* Eliminate the overlap over JS_REGEXP_TYPE.
* Also replace FIRST_JS_OBJECT with FIRST_JS_RECEIVER, but only use it where
we exclusively talk about the internal representation type.
* Insert JS_PROXY and JS_FUNCTION_PROXY in the appropriate places.
- Fix all checks concerning classification, especially for functions, to
use the CALLABLE_SPEC_OBJECT range (that includes funciton proxies).
- Handle proxies in SetProperty (that was the easiest part :) ).
- A few simple test cases.
R=kmillikin@chromium.org
Review URL: http://codereview.chromium.org/6992072
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8126 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Always use CpuFeaturesImpliedByCompiler() when selecting CPU features. This checks both for CAN_USE_ARMV7_INSTRUCTIONS and CAN_USE_VFP_INSTRUCTIONS and for GCC preprocessor symbols. This will support using the CAN_USE_XXX for a simulator build used for generating a snapshot followed by a crosscompile using -march= and -mfpu= for selecting the (minimal) target device CPU features. The snapshot will use instructions based on the CAN_USE_XXX whereas the target will at least use features based on both CAN_USE_XXX and -march= and -mfpu=, but will try runtime CPU feature detection a well looking for somethis better.
Remove the compiler based CPU feature detection from the OS::CpuFeaturesImpliedByPlatform() as it did not belong there. Also was already in the CpuFeaturesImpliedByCompiler().
Add the variable 'v8_can_use_vfp_instructions' to the GYP file which can be used to turn on CAN_USE_VFP_INSTRUCTIONS when building V8. I did not add any -mfpu= cflags for this, as there are several options here (e.g. vfp and neon).
R=erik.corry@gmail.com, karlklose@chromium.org
BUG=none
TEST=none
Review URL: http://codereview.chromium.org//6904164
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7754 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Switched to using binary low-level log instead of the textual log used
by the ticks processor. The binary log contains code-related events,
code object names, and their bodies. When writing to the log we ask
glibc to use a larger buffer. To avoid complex processing of the
snapshot log (which is still textual) the serializer emits final
snapshot position to code name mappings that can be quickly be read
without replaying the snapshot log. (This might be useful for the
ticks processor.)
Review URL: http://codereview.chromium.org/6904127
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7729 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This is for mobile platforms where application footprint size is
important. To avoid including compression libraries into V8, we assume
that the host machine have them (true for Linux), and rely on embedder
to provide decompressed data.
Currently, only snapshot data can be comressed. It is also possible to
compress libraries sources, but it is more involved and will be
addressed in another CL.
BUG=none
TEST=none
Review URL: http://codereview.chromium.org/6901090
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7724 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Add option armeabi to the SCons build for selecting the floating point variant to use. Also add externally defined CCFLAGS environment for all targets. Run test.py with option -S armeabi=hardfloat to test with hardfloat enabled.
Make selecting hardfloat EABI variant a build-time option instead of a runtime option.
Add a simple check of the EABI variant during V8 initialization to exit if the compilation was not configured correctly. The reason for this is that GCC does not provide a compile time symbol defining the EABI variant. This check is not fool-proof as it cannot check the compilation configuration used for the snapshot if any.
R=karlklose@chromium.org, erik.corry@gmail.com
BUG=none
TEST=none
Review URL: http://codereview.chromium.org//6905098
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7715 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Crankshaft is now the default on all platforms. This is the first
patch on the way to removing the classic code generator from the
system.
This time with no removal of the crankshaft flag. --nocrankshaft is
not at all the same as --always-full-compiler which I had used instead
for testing. That was what caused timeouts on the buildbots because of
repeated attempts to optimize hot functions. It makes sense to keep
the crankshaft flag in case you want to run only with the full
compiler and with no adaptive compilation.
R=vitalyr@chromium.org
Review URL: http://codereview.chromium.org/6759070
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7486 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The test suite builds the preparser test program and runs it on each .js file in
the test/preparser directory.
Currently it only checks that preparsing runs without crashing or erroring.
This also implicitly tests that the preparser library can be built.
TEST=test/preparser/*.js
Review URL: http://codereview.chromium.org/6777010
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7436 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This patch adds common infrastructure for fast TLS support and
implementation on win32. More implementations will be added soon.
Fast TLS is controlled by V8_FAST_TLS define which is enabled by
default in our gyp and scons builds. The scons build has
fasttls={on,off} option so that we can see the effects of slow TLS
when needed.
Review URL: http://codereview.chromium.org/6696112
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7375 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Fix the shell to not use functions from the v8::internal namespace when building with V8 in a shared library.
Remove the v8_preparser library. The dependencies for this target needs to be resolved after isolates have landed.
Review URL: http://codereview.chromium.org/6696067
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7337 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Because we run all tests three times with different variant flags (to
test crankshaft) we might end up in a situation where we try to write
to the same serilization file from two different threads
simultaneously. The patch concats the variant flags at the end of the
serialization file name.
Review URL: http://codereview.chromium.org/6688068
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7285 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The main issue was due to multiple recompilations of functions. Now
code objects are grouped by function using SFI object address.
JSFunction objects are no longer tracked, instead we track SFI object
moves. To pick a correct code version, we now sample return addresses
instead of JSFunction addresses.
tools/{linux|mac|windows}-tickprocessor scripts differentiate
between code optimization states for the same function
(using * and ~ prefixes introduced earlier).
DevTools CPU profiler treats all variants of function code as
a single function.
ll_prof treats each optimized variant as a separate entry, because
it can disassemble each one of them.
tickprocessor.py not updated -- it is deprecated and will be removed.
BUG=v8/1087,b/3178160
TEST=all existing tests pass, including Chromium layout tests
Review URL: http://codereview.chromium.org/6551011
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6902 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Analyses full minidump (.dmp) files.
Shows the processor state at the point of exception including the
stack of the active thread and the referenced objects in the V8
heap. Code objects are disassembled and the addresses linked from the
stack (pushed return addresses) are marked with "=>".
Review URL: http://codereview.chromium.org/6312058
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6896 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Strict mode assignment to undefined reference.
Simple assignments (x = <value>) use CODE_TARGET_CONTEXT.
StoreIC stores its own strictness in extra_ic_state.
The strcitness is propagated as further ic stubs are generated.
Details:
* ReferenceError on assignment to non-resolvable reference in strict mode.
* Fix es5conform test expectation file.
* Add es5conform test suite into .gitignore.
* Fix Xcode project.
* Change implemented in virtual frame code generator, as well as full-codegen
for all architectures.
* Fix debugger test.
* Fix comment for CODE_TARGET_CONTEXT
* Implement remaining StoreIC stubs to be strict mode aware.
* Trace extra_ic_state() for ic code stubs.
Code Review URL: http://codereview.chromium.org/6474026/
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6760 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Strict mode assignment to undefined reference.
Simple assignments (x = <value>) use CODE_TARGET_CONTEXT.
StoreIC stores its own strictness in extra_ic_state.
The strcitness is propagated as further ic stubs are generated.
Details:
* ReferenceError on assignment to non-resolvable reference in strict mode.
* Fix es5conform test expectation file.
* Add es5conform test suite into .gitignore.
* Fix Xcode project.
* Change implemented in virtual frame code generator, as well as full-codegen
for all architectures.
* Fix debugger test.
* Fix comment for CODE_TARGET_CONTEXT
* Implement remaining StoreIC stubs to be strict mode aware.
* Trace extra_ic_state() for ic code stubs.
Code Review URL: http://codereview.chromium.org/6474026/
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6756 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Instead of constructing a temporary container for all LOperands of each
instruction, the register works directly on the LIR instructions that
provide an abstract interface for input/output/temp operands.
This saves allocation of zone memory and speeds up LIR construction,
but makes iterating over all uses in the register allocator slightly
more expensive because environment uses are stored in a linked list of
environments. We can fix this by using a flat representation of LOperands.
Review URL: http://codereview.chromium.org/6352006
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6638 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Instead of spilling and then immediately restoring eax to resolve
memory to memory moves, the gap move resolver now tracks registers
that are known to be free and uses one if available. If not it spills
but restores lazily when the spilled value is needed or at the end of
the algorithm.
Instead of using esi for resolving cycles and assuming it is free to
overwrite because it can be rematerialized, the gap move resolver now
resolves cycles using swaps, possibly using a free register as above.
The algorithm is also changed to be simpler: a recursive depth-first
traversal of the move dependence graph. It uses a list of moves to be
performed (because it mutates the moves themselves), but does not use
any auxiliary structure other than the control stack. It does not
build up a separate list of scheduled moves to be interpreted by the
code generate, but emits code on the fly.
Review URL: http://codereview.chromium.org/6263005
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6344 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This patch enables two new flags for the tools/test.py script;
--shard-count - giving the ability to split the tests to be run
into shard-count chunks.
--shard-run - giving the ability to specify which of the shards to actually run.
Example
tools/test.py -j15 --shard-count=2 --shard-run=1 mozilla
would split the mozilla tests into two chunks and run the tests in the first chunk
Running:
tools/test.py -j15 --shard-count=2 --shard-run=1 mozilla
tools/test.py -j15 --shard-count=2 --shard-run=2 mozilla
is equivalent (in terms of test coverage) of just running:
tools/test.py -j15 mozilla
In addition, tests are now sorted before they are returned from the
test specific ListTests methods (sputnik and mozilla tests where
already sorted before they where returned).
This change is needed to split a single test suite over two slaves on
the waterfall.
Review URL: http://codereview.chromium.org/6127003
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6248 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
objectprint=on (defaults to off) option (which defines OBJECT_PRINT).
2. Added the ability to print objects to a specified file instead of
just stdout.
3. Added a use_verbose_printer flag (true by default) to allow some
object printouts to be less verbose when the flag is false.
4. Fixed a bug in VSNPrintF() where it can potentially write into an
empty char vector.
Patch by Mark Lam from Hewlett-Packard Development Company, LP
Review URL: http://codereview.chromium.org/5998001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6080 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This is based on the structore used in chromium with a script wrapping the call to gyp itself and the default processing of common.gypi.
It is possible to build all our targets on Intel Linux for all architectures (ia32, x64 and ARM simulator). When this is committed I wil take a look at Windows.
See the README.txt file in the changelist for the current way of using it.
Review URL: http://codereview.chromium.org/5701001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6000 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
x64 where crankshaft is not the default. Add ability to add custom
expectations for running in this special crankshaft mode.
The expectations are not updated in this change. There are a couple of
bugs that I would like to fix before doing that. Otherwise the lists
will be very long. :)
Review URL: http://codereview.chromium.org/5787001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5962 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Make checks.h not depend on flags.h or global.h (or anything else except
include/v8stdint.h). Only checks.cc has the dependencies (so another
implementation of checks.cc can be provided by the preparser).
Now files depending on checks.h (using ASSERT macros) can include it
directly without depending on all of v8.
Review URL: http://codereview.chromium.org/4576001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5775 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Since 2.6.31 perf_events interface has been available in the
kernel. There's a nice tool called "perf" (linux-2.6/tools/perf) that
uses this interface and provides capabilities similar to oprofile. The
simplest form of its usage is just dumping the raw log (trace) of
events generated by the kernel. In this patch I'm adding a script
(tools/ll_prof.py) to build profiles based on perf trace and our code
log. All the heavy-lifting is done by perf. Compared to oprofile agent
this approach does not require recompilation and supports code moving
garbage collections.
Expected usage is documented in the ll_prof's help. Basically one
should run V8 under perf passing --ll-prof flag and then the produced
logs can be analyzed by tools/ll_prof.py.
The new --ll-prof flag enables logging of generated code object
locations and names (like --log-code), and also of their bodies, which
can be later disassembled and annotated by the script.
Review URL: http://codereview.chromium.org/3831002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5663 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
o Only substitute constant values for full-words and not for
accidental partial matches.
o Keep the order of macros as in macros.py and allow depending on the
previous macros. We used to allow depending on macros that
happened to sort after the current one in the dictionary.
Review URL: http://codereview.chromium.org/2800042
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5022 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Fix issues so v8 could be built as a DLL.
-. get rid of all the compiler warning by moving dllexport/dllimport
to the individual members for classes which have inline members.
-. update v8 gyp to build v8.dll for chromium multi-dll version (win
and component==shared_library)
Note: most of the code are contributed by sjesse.
Code review URL: http://codereview.chromium.org/2882009/show
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5006 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Chromium build.
v8.gyp no longer sets any V8_TARGET_ARCH_* macro on the Mac. Instead, the
proper V8_TARGET_ARCH_* macro will be set by src/globals.h in the same way as
the V8_HOST_ARCH_* macro when it detects that no target macro is currently
defined. The Mac build will attempt to compile all ia32 and x86_64 .cc files.
#ifdef guards in each of these target-specific source files prevent their
compilation when the associated target is not selected. For completeness,
these #ifdef guards are also provided for the arm and mips .cc files.
BUG=706
TEST=x86_64 Mac GYP/Xcode-based Chromium build (still depends on other changes)
Review URL: http://codereview.chromium.org/2133003
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4666 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
of having a list of virtual frame pointers in the jump
target we have one virtual frame, which is the frame that
all have to merge to to branch to that frame. The virtual
frame in the JumpTarget is inside the JumpTarget, rather than
being an allocated object that is pointed to. Unfortunately
this means that the JumpTarget class has to be able to see
the size of a VirtualFrame object to compile, which in turn
lead to a major reorganization of related .h files. The
actual change of functionality in this change is intended
to be minimal (we now assert that the virtual frames match
when using JumpTarget instead of just assuming that they do).
Review URL: http://codereview.chromium.org/1961004
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4631 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The V8 GYP file now uses its own target architecture. It default to the standard target_arch, but can be set to a separate value. E.g. using
export GYP_DEFINES="target_arch=ia32 v8_target_arch=arm"
makes it possible to have the V8 ARM simulator be used in a IA32 build.
Added some checking of supported host/target architecture combinations.
Review URL: http://codereview.chromium.org/1790001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4490 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This is to make possible enabling usage of the new profiling subsystem
in Chromium without much hassle. The idea is pretty simple: unless the
new profiling API is used, all works as usual, as soon as Chromium
starts to use the new API, it will work too.
Review URL: http://codereview.chromium.org/1635005
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4382 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Instead of testing the value of a constant frame element to determine
the type we compute its type information at construction time.
This speeds up querying the type information during code generation.
This change also adds support for Integer32 constants and sets
the type information accordingly.
Review URL: http://codereview.chromium.org/1277001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4256 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Circular queues serve as a transport for communicating between
VM, stack sampler and analyzer threads. Logging requirements
for VM and stack sampler are completely different, that's why
I introduced two different versions of CQs.
Review URL: http://codereview.chromium.org/1047002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4159 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
A variable usage analysis pass was run on toplevel and lazily-compiled
code but never used. Remove this pass and the data structures it
builds.
The representation of variable usage for Variables has been changed
from a struct containing a (weighted) count of reads and writes to a
simple flag. VariableProxies are always used, as before. The unused
"object uses" is removed.
Review URL: http://codereview.chromium.org/669270
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4052 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Introducing a virtual-frame-inl.h file containing some platform-independent
virtual frame function which are small enough to be inlined.
Removed unnecessary #include of virtual-frame.h from register-allocator-inl.h
and added the necessary explicit includes in a number of files.
Review URL: http://codereview.chromium.org/660104
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3962 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Each frame element gets a new attribute with number type information. A frame element can be:
- smi
- heap number
- number (i.e. either of the above)
- or something else.
The type information is propagated along with all virtual frame operations.
Results popped from the frame carry the number information with them.
Two optimizations in the code generator make use of the new
information:
- GenericBinaryOpSyub omits map checks if input operands are numbers.
- Boolean conversion for numbers: Emit inline code for converting a number (smi or heap number) to boolean. Do not emit call to ToBoolean stub in this case.
Review URL: http://codereview.chromium.org/545007
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3861 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This change adds a post-order numbering to AST nodes that
are relevant for the fast code generator. It is only invoked
together with the fast compiler.
Also changed the ast printer to print the numbering for
testing purposes if it is present.
Review URL: http://codereview.chromium.org/553134
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3738 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The problem appeared due to a fact that stubs doesn't create a stack
frame, reusing the stack frame of the caller function. When building
stack traces, the current function is retrieved from PC, and its
callees are retrieved by traversing the stack backwards. Thus, for
stubs, the stub itself was discovered via PC, and then stub's caller's
caller was retrieved from stack.
To fix this problem, a pointer to JSFunction object is now captured
from the topmost stack frame, and is saved into stack trace log
record. Then a simple heuristics is applied whether a referred
function should be added to decoded stack, or not, to avoid reporting
the same function twice (from PC and from the pointer.)
BUG=553
TEST=added to mjsunit/tools/tickprocessor
Review URL: http://codereview.chromium.org/546089
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3673 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
