Allow keyed store/load stubs to switch between external array and fast JS arrays without forcing a state transition to the generic stub.
There CL consists of two pieces of functionality. First, code stubs for fast element arrays don't immediately transition to the MEGAMORPHIC state when there's a map mismatch. Second, two ICs are cached per map for fast elements, the MONOMORPHIC version, and a new MEGAMORPHIC version that handles two or more different maps. Currently, the only array types supported by the MEGAMORPHIC stub are fast elements for objects and JSArrays.
BUG=
TEST=
Review URL: http://codereview.chromium.org/6894003
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7917 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
1) Add new type JSProxy for representing proxy objects.
Currently devoid of functionality, i.e., all properties are undefined.
2) Some rudimentary global $Proxy functions to create proxies.
Next step: Hook up getProperty and getOwnProperty handlers. Will probably
require introducing a new LookupResult type, which is a mixture of
INTERCEPTOR (handles any property) and CALLBACK (calls back to JS).
Can we unify this somehow?
TODO: Should probably rename existing Proxy type to something like
"Foreign", to avoid confusion.
Review URL: http://codereview.chromium.org/6932068
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7887 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This allows us to get rid of totally fake LAST_STRING_TYPE and makes
it possible to test for symbols.
I considered splitting HCheckInstanceType into two instructions, but
it seems nice to be able to hide the instance type implementation
details from the hydrogen level.
Review URL: http://codereview.chromium.org/6964011
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7840 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
Worth mentioning:
- Specialized versions of pixel array and store/loads inside the generic stubs have been removed, since to have parity for all external arrays, 8 different versions would have to be inlined/checked.
- There's a new constant in v8.h for external arrays with pixel array elements.
Review URL: http://codereview.chromium.org/6546036
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7106 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
SetElement can cause an exception to be thrown. If its return value
isn't checked, this exception might not be handled at the correct time.
In some cases, it's a matter of returning Exception::Failure() from
a runtime function.
In other cases, code using SetElement on a JSArray has been changed
to setting directly on a FixedArray and only creating the JSArray
at the end.
Review URL: http://codereview.chromium.org/6588130
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7039 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Strict mode flag is passed to runtime DELETE function
and then to JSObject::Delete(Property/Element) as STRICT_DELETION enum.
When deleting non-configurable property/eleemnt, TypeError is thrown.
Adding mozilla test to .gitignore.
Incorporate CR feedback.
Review URL: http://codereview.chromium.org/6515005/
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6782 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
This patch adds H- and L-variants of StringCharCodeAt and StringLength.
StringCharCodeAt is used to inline a constant function call of
String.prototype.charCodeAt and to implement the corresponding inline
runtime function. It does not yet use the recently introduced extra IC
state. (We can specialize on string encoding and avoid deopts because
of out of bounds accesses.)
StringLength needs more work because the stub version of it also
supports strings wrappers and it matters in some cases. (We have to
separate the string only case.)
Review URL: http://codereview.chromium.org/6243008
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6408 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Extra IC state is only two bits and only supported for call IC-s for
now. To change its extra state an IC stub jumps to a new miss stub
that goes to runtime as usual but then instead of going megamorphic
generates a monomorphic stub with the updated state.
Review URL: http://codereview.chromium.org/6344005
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6370 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
In the past we only accepted functions as argument for setting an
accessor. Since one should be able to set an accessor to undefined
this had to be changed to take either.
In addition, we did not lookup properties in the prototype chain,
causing us to call the setter of an existing accessor up the prototype
chain when trying to replace an existing accessor (that was not local)
with a data property.
Review URL: http://codereview.chromium.org/5861006
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6045 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Change more functions used by the Compiler class to have a uniform
interface: they get passed as argument an input/output pointer to a
CompilationInfo that they mutate if they succeed, and they return a
flag telling whether they succeeded.
Also, remove some unnecessary timers.
Review URL: http://codereview.chromium.org/3561012
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5583 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The current parameters (initial slack = 6, kGenerousAllocationsCount = 16)
caused 15-20% performance regression on 3d-raytrace on x64
(visible both in standalone shell and in the web harness). This is very
likely some kind of an alignment problem (it goes away completely with --prof).
A similar problem can be observed on ia32 with initial slack=2.
Increased initial slack to 8 and decreased constructions count to 8.
This made the regression go away (and did not harm any of the other tests).
Review URL: http://codereview.chromium.org/3595002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5571 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The object's space in Page starts after Page header and is aligned to kMapAlignment which is 32 bytes on 32-bit and 8 bytes on 64-bit.
In case of 64-bit target, the current page header size is exactly 32 bytes so we get the code magically aligned at 32 bytes but it is better to have a separate CODE_POINTER_ALIGN macro to make sure the object space in Page is aligned properly for both maps and code.
There could be a small waste of bytes sometimes (since both Page header and Code header sizes are aligned separately) but it seems the optimal one would involve cross-dependencies between .h files and not clear if it's worth it.
This is a back-port from Isolates branch.
Review URL: http://codereview.chromium.org/3461021
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5526 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Finally sovles the problem that r5342 attempted to solve.
When adding a stub to a map's code cache we need to make
sure that this map is not used by object that do not need
this stub.
Existing solution had 2 flaws:
1. It checked that the map is cached by asking the current context.
If the object escaped into another context then NormalizedMapCache::Contains
returns false negative.
2. If a map gets evicted from the cache we should not try to modify it
even though Contains returns false.
This patch implements much less fragile solution of the same problem:
A map now has a flag (is_shared) that is set once the map is added
to a cache, stays set even after the cache eviction, and is cleared
if the object goes back to fast mode.
Added a regression test.
Review URL: http://codereview.chromium.org/3472006
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5518 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The number of inobject properties used to be derived from the number
of this property assignments in the constructor (and increased by 2 to
allow for properties added later). This very often leads to wasted inobject
slots.
This patch reclaims some of the unused inobject space by the following method:
- for each constructor function the first several objects are allocated using the initial
("generous) instance size estimation (this is called 'tracking phase').
- during the tracking phase map transitions are tracked and actual property counts are collected.
- at the end of the tracking phase instance sizes in the maps are decreased if necessary
(starting with the function's initial map and traversing the transition tree).
- all further allocation use more realistic instance size estimation.
Shrinking generously allocated objects without costly heap traversal is made possible
by initializing their inobject properties with one_pointer_filler_map (instead of undefined).
The initial slack for the generous allocation is increased from 2 to 6 which really helps some tests.
Review URL: http://codereview.chromium.org/3329019
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5510 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
r5147 wrongly assumed that a code cache for a slow case map is always empty.
This patch solves this: whenever we attempt to add a stub to a map's code cache
we check that this map is cached. If it is we give the object its own copy
of the map and only then modify the map.
Review URL: http://codereview.chromium.org/3134027
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5342 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Object model changes
----------------------------------------
New fixed_cow_array_map is used for the elements array of a JSObject
to mark it as COW. The JSObject's map and other fields are not
affected. The JSObject's map still has the "fast elements" bit set. It
means we can do only the receiver map check in keyed loads and the
receiver and the elements map checks in keyed stores. So introducing
COW arrays doesn't hurt performance of these operations. But note that
the elements map check is necessary in all mutating operations because
the "has fast elements" bit now means "has fast elements for reading".
EnsureWritableFastElements can be used in runtime functions to perform
the necessary lazy copying.
Generated code changes
----------------------------------------
Generic keyed load is updated to only do the receiver map check (this
could have been done earlier). FastCloneShallowArrayStub now has two
modes: clone elements and use COW elements. AssertFastElements macro
is added to check the elements when necessary. The custom call IC
generators for Array.prototype.{push,pop} are updated to avoid going
to the slow case (and patching the IC) when calling the builtin should
work.
COW enablement
----------------------------------------
Currently we only put shallow and simple literal arrays in the COW
mode. This is done by the parser.
Review URL: http://codereview.chromium.org/3144002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5275 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This should help in cases like:
function Constructor() {
this.foo = constFunction;
this.bar = "baz";
}
for (...) {
o = new Constructor();
// Constant call IC will work.
o.foo();
// Inlined property load will see the same map.
use(o.bar);
}
This change also fixes a latent bug in custom call IC-s for strings
exposed by string-charcodeat.js.
Review URL: http://codereview.chromium.org/3160006
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5254 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This adds a check to the fast case string add to ensure that the String object still have the default valueOf function. The default valueOf is sitting on a hidden prototype of String.prototype.
Before using the fast case valueOf the object is checked for a local valueOf property. For slow case objects this check always reports true (the dictionary is not probed, so valueOf might be there) and for fast case objects the descriptor array is checked for the valueOf symbol (just liniar scan). After that the prototype is checked for beeing the initial value of String.prototype. If this all pass (that is the default valueOf is still in place) this result is cached on the map making the check fast the next time.
This is only implemented in the optimizing compiler, as the two usages of %_IsStringWrapperSafeForDefaultValueOf is never hit by the full compiler.
I will port to x64 and ARM when this has been reviewed for ia32.
I will remove the performance counters prior to final commit.
BUG=http://code.google.com/p/v8/issues/detail?id=760
TEST=test/mjsunit/regress/regress-760-1.js
TEST=test/mjsunit/regress/regress-760-2.js
Review URL: http://codereview.chromium.org/3117006
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5252 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
in allowing more flexible compilation and to simplify builtins lookup.
This changes a number of places where code objects are assigned to
SharedFunctionInfo objects to also assign this code object to the
JSFunction. In addition, the code flushing is changed slightly to
accomodate this (we need to flush the code from functions pointing to
SharedFunctionInfo objects that has already been flushed).
Review URL: http://codereview.chromium.org/3120006
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5233 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
We do not have a GlobalContext class.
We do, however, have a SerializedScopeInfo class that inherits FixedArray.
Starting comment is also slightly misleading, since not all objects in the hierarchy is described in objects.h (e.g., Context is described in contexts.h).
Review URL: http://codereview.chromium.org/2811057
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5101 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The static ScopeInfo members moved into this class.
The new class is named ScopeInfoObject which I am not proud of,
better ideas are very welcome.
Also got rid of the sentinels in the serialized scope info which saves 3 words per function
and is not slower.
Review URL: http://codereview.chromium.org/2908009
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5067 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Use virtually dispatched specialized scavengers instead of single generic ScavengeObjectSlow implementation.
Rollback of r5041 with assertion checking callback alignment removed. Map space is iterated in a special fashion during scavenges so special callback alignment is not required.
Review URL: http://codereview.chromium.org/2950003
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5047 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
A potential issue with this change is creating lots of maps when
objects flip between fast/slow elements modes. We could add special
transitions to avoid this. Yet testing this on our benchmarks, gmail,
and wave seems to indicate that this is not a real problem.
Review URL: http://codereview.chromium.org/2870018
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4941 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This changes the way the constants kJSObjectType, kFirstNonstringType and kProxyType are made available to the inlined part of the V8 API. This change to fixed constants resolves linker this linker error Windows
error LNK2001: unresolved external symbol "public: static int v8::internal::Internals::kJSObjectType" (?kJSObjectType@Internals@internal@v8@@2HA)
when linking against a V8 DLL.
This change also makes it possible to build all the C++ tests with ENABLE_DEBUGGER_SUPPORT not defined. Now C++ tests run ENABLE_DEBUGGER_SUPPORT not defined, and only the JavaScript tests which tests the debugger fails when ENABLE_DEBUGGER_SUPPORT is not defined.
Review URL: http://codereview.chromium.org/2820016
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4898 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
If a two-byte string only contains ascii characters, then we can save
memory when flattening a cons string containing it. Similarly we can
use this in Array.prototype.join implementation. To track this a new
bit is added to instance type. This bit is used as a hint in generated
code and in runtime functions.
To enable testing a new V8 extension is added controlled by
--expose-externalize-string flag.
Review URL: http://codereview.chromium.org/2762008
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4894 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This adds an additional step to full gc, removing code from functions
that are no longer in the compilation cache. The code is replaced with
a lazy compile version enabling us to recompile the function in case
we do actually need it again.
Review URL: http://codereview.chromium.org/2632003
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4814 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
These string methods can be composed from two basic blocks: charCodeAt
and fromCharCode, both of which have fast cases for certain types of
inputs. In this patch these two blocks are refactored to allow
generating the fast cases without having to jump around the slow
cases. In the slow cases since they can now be invoked both from
inline runtime functions and from IC stubs we either have to
save/restore state of the current frame or enter/leave a new internal
frame. This is handled by new RuntimeCallHelper interface. Its
implementation for virtual frame is based on FrameRegisterState class
extracted from DeferredCode class.
Review URL: http://codereview.chromium.org/2087009
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4733 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
- New сardmarking write barrier handles large objects and normal objects in a similar fashion (no more additional space for pointer tracking is required, no conditional branches in WB code).
- Changes to enable oldspaces iteration without maps decoding:
-- layout change for FixedArrays: length is stored as a smis (initial patch by
Kevin Millikin)
-- layout change for SharedFunctionInfo: integer fields are stored as smi on
arm, ia32 and rearranged on x64.
-- layout change for String: meaning of LSB bit is fliped (1 now means hash not
computed); on x64 padding is added.
-- layout of maps is _not_ changed. Map space is currently iterated in a special
way.
Review URL: http://codereview.chromium.org/2144006
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4715 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Currently one can only define accessors on object templates. This patch
allows to create accessors on the fly.
These accessors could control access to elements as well. This element
support is somewhat rudimentary and may require future work (for example,
we probably don't want to convert index into a string.)
Review URL: http://codereview.chromium.org/2123012
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4714 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
-- layout change for FixedArrays: length is stored as a smis (initial patch by Kevin Millikin)
-- layout change for SharedFunctionInfo: integer fields are stored as smi on arm, ia32 and rearranged on x64.
-- layout change for String: meaning of LSB bit is fliped (1 now means hash not computed); on x64 padding is added.
-- layout of maps is _not_ changed. Map space is currently iterated in a special way.
- Cardmarking write barrier. New barrier handles large objects and normal objects in a similar fashion (no more additional space for pointer tracking is required, no conditional branches in WB code).
Review URL: http://codereview.chromium.org/2101002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4685 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
* Faster hashing for sequential strings.
* When adding short external two-byte strings try to convert them
back to ascii. Chances are high the embedder uses two-byte
representation even for ascii strings. This optimization saves
memory and makes hashing faster.
Review URL: http://codereview.chromium.org/1444001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4300 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
A separate object type for the code cache have been added. This object has two different code caches. The first one (default_cache) is a fixed array organized in the same way as the as the code cache was before. The second cache (global_access_cache) is for code stubs to access the global object. This cache is organized as a hash table taking the property name and code flags as the key.
The reason for separating the global access stubs into a hash table representation is that the number of these is not bounded in the same was as the other types.
This is a remake of r3952 (http://codereview.chromium.org/652119) which have the additional ability to look for the index of code stubs for access to the global object.
BUG=http://code.google.com/p/v8/issues/detail?id=613
Review URL: http://codereview.chromium.org/717001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4066 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
A separate object type for the code cache have been added. This object has two different code caches. The first one (default_cache) is a fixed array organized in the same way as the as the code cache was before. The second cache (global_access_cache) is for code stubs to access the global object. This cache is organized as a hash table taking the property name and code flags as the key.
The reason for separating the global access stubs into a hash table representation is that the number of these is not bounded in the same was as the other types.
BUG=613
Review URL: http://codereview.chromium.org/652119
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3952 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Although algorithmically correct, the compiler would not allow to instantiate
a BitField that uses all 32 bits without warnings about a too large shift
count. As a consequence we were limited to 31 bit values when using BitField.
This happened when instantiating a bitfield BitField<T, shift, size> with
[shift=0, size=32] or [shift=31, size=1] or more general any
[shift=X, size=32-X]
As side-effect of the new implementation the compiler now warns if we ever
try instantiating a bitfield with size 0.
Review URL: http://codereview.chromium.org/606063
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3910 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Moved all the logic to a function on SharedFunctionInfo (including the flag check) to make things more readable.
Changed the check for setter to do a lookup for a named setter for each of the properties assigned in the constructor.
Added tests using accessors and interseptors set through the API.
Added fast case objects to the mjsunit test.
TEST=test/mjsunit/setter-on-constructor-prototype.js
TEST=test/cctest/test-api/SetterOnConstructorPrototype
TEST=test/cctest/test-api/InterceptorOnConstructorPrototype
Review URL: http://codereview.chromium.org/619006
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3893 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Simple objects which are constructed without calling the actual constructor function did not take setters defined on prototype chain of the new object into account.
Constructing objects this way is now not done if there are setters involved on the prototype chain of the new object.
This only fixes the case where the setter is found when the first object from a constructor is created. If the prototype chain is changed new objects will on take any change to setters into account.
TEST=test/mjsunit/setter-on-constructor-prototype.js
Review URL: http://codereview.chromium.org/606062
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3879 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
1. Avoid using SKIP_WRITE_BARRIER when we don't have to (smis).
2. Check and document the remaining uses of SKIP_WRITE_BARRIER.
3. Only allow GetWriteBarrierMode when in an AssertNoAllocation scope.
The only functional change should be in DeepCopyBoilerplate where we
no longer use the write barrier mode (because of allocations). I'm
running benchmarks to see if this has a measurable impact on performance.
Review URL: http://codereview.chromium.org/558041
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3743 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Calls to RegExp no longer have to be via a call to the runtime system. A new stub have been added which can handle this call in generated code. The stub checks all the parameters and creates RegExp entry frame in the same way as it is created by the runtime system. Bailout to the runtime system is done whenever an uncommon situation is encountered or when the static data used is not initialized. After running the native RegExp code the last match info is updated like in the runtime system.
Currently only ASCII strings are handled.
Added another argument to the RegExp entry frame. It indicated whether the call is direct from JavaScript code or through the runtime system. This information is used when RegExp execution is interrupted. If an interruption happens when RegExp code is called directly a retry is issued causing the interruption to be handled via the runtime system. The reason for this is that the direct call to RegExp code does not support garbage collection.
Review URL: http://codereview.chromium.org/521028
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3542 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
On 32-bit the maps are now aligned on a 32-byte boundary in order to encode more maps during compacting GC. The actual size of a map on 32-bit is 28 bytes making this change waste 4 bytes per map.
On 64-bit the encoding for compacting GC is now using more than 32-bits and the maps here are still pointer size aligned. The actual size of a map on 64-bit is 48 bytes and this change does not intruduce any waste.
My choice of 16 bits for kMapPageIndexBits for 64-bit should give the same maximum number of pages (8K) for map space. As maps on 64-bit are larger than on 32-bit the total number of maps on 64-bit will be smaller than on 32-bit. We could consider raising this to 17 or 18.
I moved the kPageSizeBits to globals.h as the calculation of the encoding really depended on this.
There are still an #ifdef/#endif in objects.h and this constant could be moved to globaks.h as well, but I kept it together with the related constants.
All the tests run in debug mode with additional options --gc-global --always-compact as well (except for a few tests on which also fails before this change when run with --gc-global --always-compact).
BUG=http://code.google.com/p/v8/issues/detail?id=524
BUG=http://crbug.com/29428
TEST=test/mjsunit/regress/regress-524.js
Review URL: http://codereview.chromium.org/504026
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3481 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
For scripts originating from a call to eval the Script object used to hold a reference to the function from where the eval was called together with the code offset within that function of the eval call. This is used by the stack trace and is part of the debugger protocol. In order to avoid storing the function the script, the position within the script and the name of the function calling eval is stored instead. This avoids holding context dependent objects in the script object.
The calculation of the position of the eval in the script holding the eval is now done when the eval script is compiled as it is not possible to postpone this unless a reference is kept to the generated code for the function calling eval.
BUG=http://code.google.com/p/v8/issues/detail?id=528
TEST=cctest/test-api/Regress528
Review URL: http://codereview.chromium.org/450034
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3393 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Storing a JSArray in the Script object could cause an indirect reference from the compilation cache to a global object to be created. Now the line ends are only stored as a FixedArrya and when that is needed in JavaScript a JSArray copy is created. Changed some of the JavaScript code to cache the line ends in a local variable for better performance.
BUG=http://code.google.com/p/v8/issues/detail?id=528
TEST=test/test-api/Bug528
Review URL: http://codereview.chromium.org/434117
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3374 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The different length string types was used to encode the string length and the hash in one field. This is now split into two fields one for length and one for hash. The hash field still encodes the array index of the string if it has one. If an array index is encoded in the hash field the string length is added to the top bits of the hash field to avoid a hash value of zero.
On 32-bit this causes an additional 4 bytes to be used for all string objects. On 64-bit this will be half on average dur to pointer alignment.
Review URL: http://codereview.chromium.org/436001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3350 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
it in regular flat strings that are part of the snapshot.
After this change we don't need libraries-empty.cc any more. In
this change libraries-empty.cc is just a the same as libraries.cc
and the scons build builds it but does not use it. We can move
in stages to a situation where it is not generated at all for all
the build systems that we have.
Review URL: http://codereview.chromium.org/360050
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3238 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
* Make snapshot more compact by coding the tag and the space
in one byte. Contract some common sequences to one byte.
* Use back references only within one page. Index from the
start of the space otherwise.
* Serialize Smis as raw data rather than int-encoding them.
This takes a little more space but is faster.
Review URL: http://codereview.chromium.org/341079
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3208 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
directly-applied function literals that are themselves compiled with
the top-level code generator.
The choice is guarded by a test that the function is anonymous (thus
not expected to be recursive) and not in a loop.
A compilation hint is set in the shared function info and used to make
the choice.
Review URL: http://codereview.chromium.org/341081
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3206 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
of individual changes:
- Added infrastructure for custom stub caching.
- Push the code object onto the stack in exit calls instead of a
debug/non-debug marker.
- Remove the DEBUG_EXIT frame type.
- Add a new exit stub generator for API getters.
Review URL: http://codereview.chromium.org/330017
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3130 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
specification under development. The optimizations are patterned after
those previously done for CanvasPixelArray. This CL adds all of the
necessary framework but continues to use the generic KeyedLoadIC and
KeyedStoreIC code, to create a baseline for benchmarking purposes. The
next CL will add the optimized ICs to ic-ia32.cc and ic-x64.cc.
These new CanvasArray types have different semantics than
CanvasPixelArray; out-of-range values are clamped via C cast
semantics, which is cheaper than the clamping behavior specified by
CanvasPixelArray. Out-of-range indices raise exceptions instead of
being silently ignored.
As part of this work, pulled FloatingPointHelper::AllocateHeapNumber
up to MacroAssembler on ia32 and x64 platforms. Slightly refactored
KeyedLoadIC and KeyedStoreIC. Fixed encoding for fistp_d on x64 and
added a few more instructions that are needed for the new ICs. The
test cases in test-api.cc have been verified by hand to exercise all
of the generated code paths in the forthcoming specialized ICs.
Review URL: http://codereview.chromium.org/293023
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3096 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
When starting JS profiling under Chromium, a map from function addresses to function names is created. During it, for sourceful scripts, an attempt to access script source is made. This can cause a crash, if a source is an external string, which already has been disposed. We had a similar problem in the past with DebugGetLoadedScripts.
BUG=http://crbug.com/23768
TEST=test-log/Issue23768
Review URL: http://codereview.chromium.org/269003
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3027 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The algorithm for finding the inner-most function containing a script break point was not correct when the script only contained one function. In that case the script function and not the actual function in the script could be returned depending on the order of the objects in the heap.
TEST=cctest/test-debug/ScriptBreakPointReload
BUG=none
Review URL: http://codereview.chromium.org/193059
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2862 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This change moves the allocation of new objects into generated code. The allocation will bail out into the runtime system if the number of properties to allocate for the object exceeds the number of in-object properties.
Review URL: http://codereview.chromium.org/175045
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2797 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
For objects which only have simple assignments of the form this.x = ...; a
specialized constructor stub is now generated. This generated code allocates the
object and fills in the initial properties directly. If this fails for some
reason code continues in the generic constructor stub which in turn might pass
control to the runtime system.
Added counter to see how many objects are constructed using a specialized stub.
The specialized stub is only implemented for ia32 architecture in this change.
For x64 and ARM the generic construct stub is used.
This is change is identical to http://codereview.chromium.org/174392 (committed in r2753 and reverted in r2754) except that a few parts have already been committed from http://codereview.chromium.org/173469 (committed in r2762).
Review URL: http://codereview.chromium.org/173470
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2764 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
For objects which only have simple assignments of the form this.x = ...; a specialized constructor stub is now generated. This generated code allocates the object and fills in the initial properties directly. If this fails for some reason code continues in the generic constructor stub which in turn might pass control to the runtime system.
Added counter to see how many objects are constructed using a specialized stub.
The specialized stub is only implemented for ia32 architecture in this change. For x64 and ARM the generic construct stub is used.
Review URL: http://codereview.chromium.org/174392
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2753 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
During parsing functions are analyzed for statements of the form this.x = ...;. These assignments are categorized in two types: simple and non simple. The simple ones are where the right hand side is known to be either a constant or an argument to the function. If a function only contains statements of this type the property names are collected and for the simple assignments the index of the argument or the constant value assigned are stored as well.
When the initial map for a function is created and the function consists of only this type of assignemnts the initial map is created with a descriptor array describing these properties which will be known to always exist in an object created from the function.
The information on this property assignments is not collected during pre-parsing so if compiling using pre-parse data these optimization hints are not available.
Next step will be to use the information collected for the simple assignments to generate constructor code which will create and initialize the object from this information without calling the code for the function.
Review URL: http://codereview.chromium.org/172088
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2710 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Allocate the code stubs dictionary and non monomorphic cache dictionary with an initial size which avoids these dictionaries to be expanded during bootstrapping. This gets rid of 9 dictionary expansions during bootstrapping.
Preallocate the dictionary when normalizing an object to a size sufficient for holding the number of properties which is expected to be added to the object. This is used when ceating an object from an object literal boilerplate where multiple properties are known to be added. This gets rid of 10 dictionary expansions during bootstrapping.
There are now 3 dictionary expansions left during bootstrapping.
Review URL: http://codereview.chromium.org/160382
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2584 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The abstractions have led to bugs because it looks like descriptor
streams are GC safe but they are not.
I have moved the descriptor stream helper functions to descriptor
arrays and I find most of the code just as readable now as it was
before.
Review URL: http://codereview.chromium.org/149458
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2428 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
space is similar to map space in that it has fixed-size objects. A
common superclass for a space with fixed size objects is used for the
map space and cell space.
Allocate all cells in cell space. Handle it during all GCs. Modify
the free-list node representation (so that the size is not at a fixed
offset in all cells) to allow two-pointer free-list nodes. Clean up
some stuff in the MC collector.
Review URL: http://codereview.chromium.org/155211
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2411 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Error, ReferenceError, etc. are given a stack property that gives a
stack trace. Here's an example stack trace:
ReferenceError: FAIL is not defined
at Constraint.execute (deltablue.js:527)
at Constraint.recalculate (deltablue.js:426)
at Planner.addPropagate (deltablue.js:703)
at Constraint.satisfy (deltablue.js:186)
at Planner.incrementalAdd (deltablue.js:593)
at Constraint.addConstraint (deltablue.js:164)
at Constraint.BinaryConstraint (deltablue.js:348)
at Constraint.EqualityConstraint (deltablue.js:517)
at chainTest (deltablue.js:809)
at deltaBlue (deltablue.js:881)
at deltablue.js:888
If Error.prepareStackTrace holds a function this function is used to
format the stack trace, for instance allowing code generators to
customize the way stack traces are reported to make them easier to
process.
Next step: performance measurements to see if it is feasible to turn
this on by default.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2302 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
* Identify heap numbers that contain non-Smi int32s and do bit
ops on them without calling the fp hardware or emulation.
* Identify results that are non-Smi int32s and write them into
heap numbers without calling the fp hardware or emulation.
* Do unary minus on heap numbers without going into the runtime
system.
* On add, sub and mul if we have both Smi and heapnumber inputs
to the same operation then convert the Smi to a double and do
the op without going into runtime system. This also applies
if we have two Smi inputs but the result is not Smi.
Review URL: http://codereview.chromium.org/119241
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2131 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Scripts now have a compilation type which can be host, eval or JSON. Host scripts are compiled through the API, eval scripts are compiled through call to evan and JSON scripts are compiled as a result of calling JSON.parse.
For scripts scripts compiled through eval the JavaScript function in top of the stack and the pc offset into the code is stored in the script object. This makes it possible to calculate the source position of the eval call later when requested. This information can be obtained through the script mirror object and is part of the script mirror JSON serialization for the debugger protocol.
Moved the enumeration ScripType into class Script and remamed to Type. The new compilation type enumeration is also inside the class Script.
This information is now shown when using the scripts command in he developer shell debugger.
Review URL: http://codereview.chromium.org/119108
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2119 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
interceptors and dont-delete attributes.
Minor change to the behavior of eval: throw exception when calling
eval in a context for which the global has been detached. This
matches the behavior of both Firefox and Safari post navigation in the
browser.
Review URL: http://codereview.chromium.org/118374
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2118 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
submitted in revisions 2093, 2094, 2099, and 2106.
There's no evidence that supports that these changes
should be the cause of the unexplained performance
regressions on the intl2 and DHTML page cyclers.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2109 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The problem was I incorrectly treated NULL result as failure to fetch
a property with a getter. However, if getter returns zero, it is
manifested as NULL pointer (see added test case).
Good news: that gives another boost as before this CL if getter returned
0, I did another slow lookup.
Review URL: http://codereview.chromium.org/119172
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2106 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
called from within a loop or not. In the past we lost the
information if a call site went megamorphic before a lazily
compiled callee was called for the first time. Now we track
that correctly (this is an issue that affects richards).
We still don't manage to track the in-loop state through a
constructor call, since constructor calls use LoadICs instead
of CallICs. This issue affects delta-blue. So in this patch
we assume that lazy compilations that don't happen through a
CallIC happen from inside a loop. I have an idea to fix this
but this patch is big enough already.
With our improved tracking of in-loop state I have switched
off the inlining of in-object loads for code that is not in
a loop. This benefits compile speed. One issue is that
eagerly compiled code now doesn't get the in-object loads
inlined. We need to eagerly compile less code to fix this.
Review URL: http://codereview.chromium.org/115744
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2046 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This issue was raised by Brett Wilson while reviewing my changelist for readability. Craig Silverstein (one of C++ SG maintainers) confirmed that we should declare one namespace per line. Our way of namespaces closing seems not violating style guides (there is no clear agreement on it), so I left it intact.
Review URL: http://codereview.chromium.org/115756
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2038 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Added a simple initial version of a context mirror object which just holds the user data from the context, and does not preserve handle identity.
A script object now holds a reference to the custom data from the context it was compiled in. This data is included in the debugger protocol for scripts.
Changed the serialization for the scripts command to use the mirror objects instaed of custom serialization. This included passing options from the debugger request to the serializer for including the full source of scripts in the response.
Review URL: http://codereview.chromium.org/111001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1877 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
ENABLE_DEBUGGER_SUPPORT is enabled by default unless it is on Android platform.
On Android platform, it can also enabled by passing -DENABLE_DEBUGGER_SUPPORT flag to the compiler.
This should not affect any existing build (I hope, cross my fingers) except the build in real Android environment (in other word, it only affects me now).
There are lot of room for code refactoring in stead of using #ifdef all over the place. I will leave this to v8 folks.
Review URL: http://codereview.chromium.org/77035
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1745 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
numerical order independently of the representation of the object.
Exchanged the order of enumeration of integer and string keys so
integer keys are first instead of string keys to better match
WebKit/JSC behavior.
Added test cases that document our enumeration order choice.
Review URL: http://codereview.chromium.org/75035
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1722 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Currently function name inference is wired with AST optimization pass to avoid introducing another pass over AST. A better solution would be to rewrite AST visitors so they can be naturally combined together in a single pass, as their current implementation doesn't allow it.
For examples of cases where function names can be inferred, see the tests file.
Review URL: http://codereview.chromium.org/62146
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1696 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
an object that holds a setter. If there are no store ics then no
flushing is done. The implementation has been tweaked so that no ICs
are cleared during normal context creation.
This may cost us some performance but I'm submitting it as it is and
if there are problems we can either decide to be smarter about when,
what and/or how we clear, or back this change out altogether.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1509 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Changed the script break points to be able to handle both break points based on script names and script ids. When break points are set through a script id the position is relative to the script itself. This is different from the script break points set through script names where the line/coulmn offset is taken into account.
This has the side effect that function break points are not converted into script break points for named scripts.
Show the script id in the D8 shell debugger when listing all scripts using the 'scripts' command.
Review URL: http://codereview.chromium.org/40317
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1468 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
1418, and 1419 from bleeding_edge until we have a fix
for the crashers we see on the distributed test infra-
structure.
We know that revision 1383 is causing issues, but I
had to revert some of the other recent RegExp changes
in order to get this part out.
Review URL: http://codereview.chromium.org/39186
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1429 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
surrounding context to figure out if the variable could be global. If
the variable could be global we check context extension objects at
runtime and use a global LoadIC if no variables have been introduced
by eval.
Fix crash bug when loading function arguments from inside eval. The
shadowed variable in the DYNAMIC_LOCAL case does not rewrite to a slot in
that case.
Review URL: http://codereview.chromium.org/28027
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1348 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Thus, instead of the following profiler records:
1.5% 1.5% LazyCompile: <anonymous>
we'll now have these:
1.5% 1.5% LazyCompile: <anonymous> richards.js:309
Basically, I translated two functions from messages.js into C++.
In the next CL I will update messages.js to use added native functions.
Review URL: http://codereview.chromium.org/19537
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1216 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Changed the name of Runtime_GetPrototype to Runtime_DebugGetPrototype to indicate that it is a debugger related function and changed its implementation to do the correct __proto__ lookup.
Added some more information to the Map debug print.
Review URL: http://codereview.chromium.org/18658
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1126 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This can lead to large objects which wastes a lot of space if we normalize properties. We therfore clear the inobject properties when normalizing properties. This is done by adjusting the instance size in the new map and overwriting the inobject properties with a filler.
Review URL: http://codereview.chromium.org/17308
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1051 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
operation. I have another version of this change that does not remove the
special inline caches for difference sized strings. The other version is ever
so slightly faster, but the nice thing about this version is that it removes
253 lines of code.
Review URL: http://codereview.chromium.org/8187
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@603 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
If a map has descendents in the map transition tree that are alive,
it is kept. Only maps such that they and all their descendants
have no live objects are collected. This happens in mark-sweep and
mark-compact garbage collections.
Review URL: http://codereview.chromium.org/8099
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@601 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
- Changed the structure of regexp objects from having two internal
fields to having a single field containing a fixed array, since it's
easier to store the whole fixed array in the cache.
- Move printing of the command to after printing std{err,out} in the
compact progress indicators in the test framework.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@579 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
- Changed WeakReferenceCallback to take a Persistent<Value> instead of
a Persistent<Object>.
- Removed Message::GetUnderline and Message::GetScriptData.
- Added Value::IsDate, Date::Cast and Date::Value.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@564 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Here is a description of the background and design of split window in Chrome and V8:
https://docs.google.com/a/google.com/Doc?id=chhjkpg_47fwddxbfr
This change list splits the window object into two parts: 1) an inner window object used as the global object of contexts; 2) an outer window object exposed to JavaScript and accessible by the name 'window'. Firefox did it awhile ago, here are some discussions: https://wiki.mozilla.org/Gecko:SplitWindow. One additional benefit of splitting window in Chrome is that accessing global variables don't need security checks anymore, it can improve applications that use many global variables.
V8 support of split window:
There are a small number of changes on V8 api to support split window:
Security context is removed from V8, so does related API functions;
A global object can be detached from its context and reused by a new context;
Access checks on an object template can be turned on/off by default;
An object can turn on its access checks later;
V8 has a new object type, ApiGlobalObject, which is the outer window object type. The existing JSGlobalObject becomes the inner window object type. Security checks are moved from JSGlobalObject to ApiGlobalObject. ApiGlobalObject is the one exposed to JavaScript, it is accessible through Context::Global(). ApiGlobalObject's prototype is set to JSGlobalObject so that property lookups are forwarded to JSGlobalObject. ApiGlobalObject forwards all other property access requests to JSGlobalObject, such as SetProperty, DeleteProperty, etc.
Security token is moved to a global context, and ApiGlobalObject has a reference to its global context. JSGlobalObject has a reference to its global context as well. When accessing properties on a global object in JavaScript, the domain security check is performed by comparing the security token of the lexical context (Top::global_context()) to the token of global object's context. The check is only needed when the receiver is a window object, such as 'window.document'. Accessing global variables, such as 'var foo = 3; foo' does not need checks because the receiver is the inner window object.
When an outer window is detached from its global context (when a frame navigates away from a page), it is completely detached from the inner window. A new context is created for the new page, and the outer global object is reused. At this point, the access check on the DOMWindow wrapper of the old context is turned on. The code in old context is still able to access DOMWindow properties, but it has to go through domain security checks.
It is debatable on how to implement the outer window object. Currently each property access function has to check if the receiver is ApiGlobalObject type. This approach might be error-prone that one may forget to check the receiver when adding new functions. It is unlikely a performance issue because accessing global variables are more common than 'window.foo' style coding.
I am still working on the ARM port, and I'd like to hear comments and suggestions on the best way to support it in V8.
Review URL: http://codereview.chromium.org/7366
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@540 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
It removes the ReplaceConstantFunction code, and replaces it with
new ConvertDescriptorToField code, that is also used in other places.
Functions CopyRemove and CopyReplace on DescriptorArray are removed.
Function AddFastProperty is simplified by removing the
CONSTANT_TRANSITION case.
Review URL: http://codereview.chromium.org/6528
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@475 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
underlying string representation of the two strings involved.
- Renamed ascii and two byte string classes to sequential ascii and
sequential two byte, and renamed IsAscii and friends to
IsAsciiRepresentation. This is to make a clear distinction between
strings with an ascii/two-byte representation, of which there is
four, and flat sequential ascii/two-byte string.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@474 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
are always odd if the bit-field bits are included.
Modified a couple of debugger tests that relied on the ordering of
elements in descriptor arrays. Descriptor arrays are sorted by
hash-code values, so the order changes if we change the hash code.
Review URL: http://codereview.chromium.org/6489
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@440 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
canonicalize maps for object literals. JSON objects
with the same set of properties names will then
share the same map.
This reduces the amount of generated code associated
with object literals.
- Added a flag canonicalize_object_literal_maps.
(default true)
- Changed the format of a function's literal array.
Only the global context is now stored in the literal prefix.
Review URL: http://codereview.chromium.org/4078
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@371 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Update the lookup and update code for code caches to deal with deleted
elements.
Do not clear the code cache for the builtins object. If there was a
matching element in the code cache, we would have hit the monomorphic
prototype failure case and removed it.
Review URL: http://codereview.chromium.org/3140
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@340 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
occured. After a monomorphic prototype failure has been detected,
other monomorphic inline caches for the same type will have a code
object in the map's code cache which is not the current target. We
recognize this case and use the code object that is in the cache
instead of going megamorphic.
Review URL: http://codereview.chromium.org/2928
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@331 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
it for scripts too. In the context of Chromium, this should
have a very positive impact on memory consumption for web apps
that run multiple tabs from the same domain with a lot of the
same JavaScript code.
For now, the cache retirement policy is really simple:
Whenever a mark-sweep collection is started we clear the
cache. This guarantees that this change will not have a
huge negative impact on memory consumption, but it may
not be ideal. We should consider a more sophisticated LRU
scheme.
Review URL: http://codereview.chromium.org/1933
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@270 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The cache is a hashtable that takes String as key and JSFunction as the value.
Caches are cleared before mark-compact GC's.
Currently I don't put caps on cache size, string size, etc.
This cuts date-parse-totfe.js runtime by half.
Review URL: http://codereview.chromium.org/457
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@173 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
* Make old_data_space non-executable on OSs and hardware that support it.
* Rename old_space to old_pointer_space (can contain pointers, esp. to new space).
* Ensure that individual pages allocated for old_space are only executable when
they are for code objects.
* Ensure Space::Setup can cope with non-aligned memory.
* Make some methods on Spaces virtual. Make a way to iterate over all spaces.
* Replace executability flag with Executability enum in order to make intent at
call site clearer.
* Fix serialization/deserialization to allocate write barrier memory for large
arrays.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@165 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
KeyedLoadIC::GenerateGeneric (on IA32), and the same on ARM.
Re-assignmed FIRST_JS_OBJECT_TYPE to JS_VALUE_TYPE.
Also changed JS_OBJECT_TYPE to FIRST_JS_OBJECT_TYPE in several places where
FIRST_JS_OBJECT_TYPE is intended.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@113 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
- Fixed mozilla test breakage caused by python's obscure module
loading rules.
- Made sure test.py propagates test failures out as the exit code of
the script.
- Remove runtime calls to get number constants. Remove Heap roots for
some special numbers.
- Fix typo in accessors.h.
- Changes CopyMap to not copy descriptors. Adds
CopyMapRemoveTransitions that copies non-transition descriptors.
Changes interface of DescriptorArray::Copy operations to simplify
them.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@21 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Added better test support.
Added load, quit and version functions to the shell sample so it's easier to run benchmarks and tests.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
In the shell sample don't print the result of executing a script, only
evaluating expressions.
Fixed issue when building samples on Windows using a shared V8
library. Added visibility option on Linux build which makes the
generated library 18% smaller.
Changed build system to accept multiple build modes in one build and
generate seperate objects, libraries and executables for each mode.
Removed deferred negation optimization (a * -b => -(a * b)) since this
visibly changes operand conversion order.
Improved parsing performance by introducing stack guard in preparsing.
Without a stack guard preparsing always bails out with stack overflow.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Cleaned up ARM version by removing top of stack caching and by introducing push/pop elimination.
Cleaned up the way runtime functions are called to allow runtime calls with no arguments.
Changed Windows build options to make sure that exceptions are disabled and that optimization flags are enabled.
Added first version of Visual Studio project files.
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Fixed the handling of '>' and '<=' to use right-to-left conversion and left-to-right evaluation as specified by ECMA-262.
Fixed a branch elimination bug on the ARM platform where incorrect code was generated because of overly aggressive branch elimination.
Improved performance of code that repeatedly assigns the same function to the same property of different objects with the same map.
Untangled DEBUG and ENABLE_DISASSEMBLER defines. The disassembler no longer expects DEBUG to be defined.
Added platform-nullos.cc to serve as the basis for new platform implementations.
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Added a few samples and support for building them. The samples include a simple shell that can be used to benchmark and test V8.
Changed V8::GetVersion to return the version as a string.
Added source for lazily loaded scripts to snapshots and made serialization non-destructive.
Improved ARM support by fixing the write barrier code to use aligned loads and stores and by removing premature locals optimization that relied on broken support for callee-saved registers (removed).
Refactored the code for marking live objects during garbage collection and the code for allocating objects in paged spaces. Introduced an abstraction for the map word of a heap-allocated object and changed the memory allocator to allocate executable memory only for spaces that may contain code objects.
Moved StringBuilder to utils.h and ScopedLock to platform.h, where they can be used by debugging and logging modules. Added thread-safe message queues for dealing with debugger events.
Fixed the source code reported by toString for certain builtin empty functions and made sure that the prototype property of a function is enumerable.
Improved performance of converting values to condition flags in generated code.
Merged disassembler-{arch} files.
git-svn-id: http://v8.googlecode.com/svn/trunk@8 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Added propagation of stack overflow exceptions that occur while compiling nested functions.
Improved debugger with support for recursive break points and handling of exceptions that occur in the debugger JavaScript code.
Renamed GetInternal to GetInternalField and SetInternal to SetInternalField in the API and moved InternalFieldCount and SetInternalFieldCount from FunctionTemplate to ObjectTemplate.
git-svn-id: http://v8.googlecode.com/svn/trunk@5 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
