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
Upgraded the CodeGenerator::ToBoolean() function in the ARM backend to use complete JIT code generation and not make runtime calls to ToBool (when VFP is enabled).
This change also includes the vcmp VFP instruction that supports a constant 0.0 as the second operand.
Patch by Subrato K De <subratokde@codeaurora.org>
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5267 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
Eventually indexed property query callbacks will return attributes
(as an integer) or an empty handle if property is not intercepted.
To gradually migrate to this new API, USE_NEW_QUERY_CALLBACK
macro would control if old or new style API is used.
So the migration plan is:
1) introduce new API which should be explictily enabled;
2) switch to new API defining USE_NEW_QUERY_CALLBACK before
include of <v8.h> (that would require changes to client code as well)
3) remove old API from v8
4) remove #define USE_NEW_QUERY_CALLBACK from clients.
BUG=http://code.google.com/p/v8/issues/detail?id=816
Review URL: http://codereview.chromium.org/3101001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5228 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
In one pathalogical case it's possible to have this->IsAsciiRepresentation() &&
!this->TryFlattenGetString()->IsAsciiRepresentation()---if cons string has two byte
string which holds only ascii chars and second is an empty string. In this case we
would return first which is not AsciiRepresentation(), however cons is.
Review URL: http://codereview.chromium.org/3036046
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5188 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
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
Added support for more precise break points when debugging and stepping. To achieve that additional nop instructions are inserted where breaking would otherwise be impossible. The number of nop instructions inserted are sufficient to make place for patching with a call to a debug break code stub. On Intel that is 5 nop's for 32-bit and 13 for 64-bit. Om ARM 3 nop instructions (12 bytes) are required.
In order to avoid inserting nop's in to many places a simple ast checker have been added to check whether there are breakable code in a statement or expression. If it is possible to break in an expression no additional break enabeling code is inserted.
Added break locations to the true and false part of a conditional expression.
Added stepping tests to cover more constructs.
These changes are only in the full compiler.
Changed the default value for the option --debugger in teh d8 shell from true to false. The reason for this is that with --debugger turned on the full compiler will be used for all code in when running d8, which can be unexpeceted.
Review URL: http://codereview.chromium.org/2693002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4820 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Eventually named property query callbacks will return attributes
(as an integer) or an empty handle if property is not intercepted.
To gradually migrate to this new API, USE_NEW_QUERY_CALLBACK
macro would control if old or new style API is used.
So the migration plan is:
1) introduce new API which should be explictily enabled;
2) switch to new API defining USE_NEW_QUERY_CALLBACK before
include of <v8.h> (that would require changes to client code as well)
3) remove old API from v8
4) remove #define USE_NEW_QUERY_CALLBACK from clients.
Review URL: http://codereview.chromium.org/2576003
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4797 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Currently if there is no query callback, V8 finds out intercepted properties'
attributes using getter: if getter returns not empty handle V8 treats
such a property as property with NONE attribues which means this property
is enumerable.
However, if there is no enumerator, this property cannot be enumerated.
Thus I think we should treat such properties as not enumerable.
Drawback of this approach is now one has to implement both query and enumerator
callbacks to implement enumerable intercepted properties.
BUG=725
Review URL: http://codereview.chromium.org/2270005
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4751 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
Changing ScriptData API to serialize its internal representation to a
const char* array.
This decouples the API from the internal representation and avoids the need for
callers to serialize themselves.
As a side-effect, ScriptData::New() no longer assumes ownership of its input.
This shouldn't matter as typical usage patterns for the old API would have
required a copy prior to calling ScriptData::New().
Review URL: http://codereview.chromium.org/2118010/show
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4710 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
