Additionally handlify the "transition" field so that GC can stop caring about it.
BUG=
Review URL: https://codereview.chromium.org/935033003
Cr-Commit-Position: refs/heads/master@{#26718}
Previous approach for property reconfiguration was to create a free-floating map with generalized representations of all fields. This patch does it right.
When property is reconfigured either by changing its kind (kData <-> kAccessor) or its attributes it implies creation of a new branch in transition tree. If such a branch already existed before reconfiguration then it should be merged with the old (or source) branch of the transition tree. Merging procedure includes all the heavy machinery such as property location changes (kDescriptor -> kField), field representation/field type generalization, map deprecation, etc.
Review URL: https://codereview.chromium.org/888623002
Cr-Commit-Position: refs/heads/master@{#26667}
First step towards replacing PropertyType with two enums: {DATA,ACCESSOR} x {CONST,WRITABLE}.
Review URL: https://codereview.chromium.org/733253004
Cr-Commit-Position: refs/heads/master@{#25417}
This is an initial step towards tracking the exact types instead of just
the representations of fields. It adds support to track up to one map of
heap object field values, eliminating various map checks on values
loaded from such fields, at the cost of making stores to such fields
slightly more expensive.
Issues with transitioning stores and fast object literals in Crankshaft
fixed.
TEST=mjsunit/field-type-tracking
R=svenpanne@chromium.org
Review URL: https://codereview.chromium.org/238773002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20746 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This is an initial step towards tracking the exact types instead of just the representations of fields. It adds support to track up to one map of heap object field values, eliminating various map checks on values loaded from such fields, at the cost of making stores to such fields slightly more expensive.
TEST=mjsunit/field-type-tracking
R=verwaest@chromium.org
Review URL: https://codereview.chromium.org/167303005
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20701 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The order by name is maintained as secondary order by using unused bits in the property details.
This is preliminary work towards sharing descriptors arrays.
The change allows us
- to get rid of the LastAdded bits in the map, binding it to the number of valid descriptors for the given map
- to avoid resorting by enumeration index to create the cache
- (maybe in the future, depending on performance) to get rid of the enumeration cache altogether.
Although generally the number_of_descriptors equals the NumberOfOwnDescriptors in the current version, this is preliminary work towards sharing descriptors, where maps may have more descriptors than are valid for the map.
Review URL: https://chromiumcodereview.appspot.com/10879013
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12385 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
In this design maps contain descriptor arrays, which in turn can contain transition arrays. If transitions are needed when no descriptor array is present, a descriptor array without real descriptors is inserted just so it can point at the transition array.
The transition array does not contain details about the field it transitions to. In order to weed out transitions to FIELDs from CONSTANT_FUNCTION (what used to be MAP_TRANSITION vs CONSTANT_TRANSITION), the transition needs to be followed and the details need to be looked up in the target map. CALLBACKS transitions are still easy to recognize since the transition targets are stored as an AccessorPair containing the maps, rather than the maps directly.
Currently AccessorPairs containing a transition and an accessor are shared between the descriptor array and the transition array. This simplifies lookup since we only have to look in one of both arrays. This will change in subsequent revisions, when descriptor arrays will become shared between multiple maps, since transitions cannot be shared.
Review URL: https://chromiumcodereview.appspot.com/10697015
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11994 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Instead of overwriting non-live transitions with NULL_DESCRIPTORs, we remove them from the array by compacting the array (shifting live values to the left) and in-place trimming the array. If the final descriptor array contains no live values (only contained transitions which are now all cleared), we move bit_field3 back from the descriptor array to the map. The descriptor array itself will be collected in the next GC.
BUG=
TEST=
Review URL: https://chromiumcodereview.appspot.com/10575032
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11922 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
With the upcoming changes to CALLBACKS properties, a predicate on the transition
type alone doesn't make sense anymore: For CALLBACKS one has to look into the
property's value to decide, and there is even the possibility of having a an
accessor function *and* a transition in the same property.
I am not completely happy with some parts of this CL, because they contain
redundant code, but given the various representations we currently have for
property type/value pairs, I can see no easy way around that. Perhaps one can
improve this a bit in a different CL, the current diversity really, really hurts
productivity...
As a bonus, this CL includes a few minor things:
* CaseClause::RecordTypeFeedback has been cleaned up and it handles the
NULL_DESCRIPTOR case correctly now. Under some (very unlikely) circumstances,
we previously missed some opportunities for monomorphic calls. In general, it
is rather unfortunate that NULL_DESCRIPTOR "shines through", it is just a
hack for the inability to remove a descriptor entry during GC, something
callers shouldn't have to be aware of.
* DescriptorArray::CopyInsert has been cleaned up a bit, preparing it for later
CALLBACKS-related changes.
* LookupResult::Print is now more informative for CONSTANT_TRANSITION.
Review URL: https://chromiumcodereview.appspot.com/9320066
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10600 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
Replaced IsValid by IsPropertyOrTransition and used IsProperty in most
of the places where IsValid was used before. Most of the time when
inspecting a lookup result we really want to know if there is a real
property present. Only for stores are we interested in transitions.
BUG=http://crbug.com/20104
TEST=cctest/test-api/NamedInterceptorMapTransitionRead
Review URL: http://codereview.chromium.org/647015
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3901 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
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 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