- Add --harmony-symbols flag.
- Add Symbol constructor; allow symbols as (unreplaced) return value from constructors.
- Introduce %CreateSymbol and %_IsSymbol natives and respective instructions.
- Extend 'typeof' code generation to handle symbols.
- Extend CompareIC with a UNIQUE_NAMES state that (uniformly) handles internalized strings and symbols.
- Property lookup delegates to SymbolDelegate object for symbols, which only carries the toString method.
- Extend Object.prototype.toString to recognise symbols.
Per the current draft spec, symbols are actually pseudo objects that are frozen with a null prototype and only one property (toString). For simplicity, we do not treat them as proper objects for now, although typeof will return "object". Only property access works as if they were (frozen) objects (via the internal delegate object).
(Baseline CL: https://codereview.chromium.org/12223071/)
R=mstarzinger@chromium.org
BUG=v8:2158
Review URL: https://codereview.chromium.org/12296026
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13786 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
in preparation of the introduction of ES6 'symbols' (aka private/unique names).
The SymbolTable became the StringTable. I also made sure to adapt all comments. The only remaining use of the term "symbol" (other than unrelated uses in the parser and such) is now 'NewSymbol' in the API and the 'V8.KeyedLoadGenericSymbol' counter, changing which might break embedders.
The one functional change in this CL is that I removed the former 'empty_string' constant, since it is redundant given the 'empty_symbol' constant that we also had (and both were used inconsistently).
R=yangguo@chromium.org
BUG=
Review URL: https://codereview.chromium.org/12210083
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13781 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Unified parameter order of CreateHandle with the rest of v8 on the way. A few
Isolate::Current()s had to be introduced, which is not nice, and not every place
will win a beauty contest, but we can clean this up later easily in smaller steps.
Review URL: https://codereview.chromium.org/12300018
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13717 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
the speed of deserializing code. The current startup
time improvement for V8 is around 6%, but code deserialization
is speeded up disproportionately, and we will soon have more
code in the snapshot.
* Removed support for deserializing into large object space.
The regular pages are 1Mbyte now and that is plenty. This
is a big simplification.
* Instead of reserving space for the snapshot we actually
allocate it now. This removes some special casing from
the memory management and simplifies deserialization since
we are just bumping a pointer rather than calling the
normal allocation routines during deserialization.
* Record in the snapshot how much we need to boot up and
allocate it instead of just assuming that allocations in
a new VM will always be linear.
* In the snapshot we always address an object as a negative
offset from the current allocation point. We used to
sometimes address from the start of the deserialized data,
but this is less useful now that we have good support for
roots and repetitions in the deserialization data.
* Code objects were previously deserialized (like other
objects) by alternating raw data (deserialized with memcpy)
and pointers (to external references, other objects, etc.).
Now we deserialize code objects with a single memcpy,
followed by a series of skips and pointers that partially
overwrite the code we memcopied out of the snapshot.
The skips are sometimes merged into the following
instruction in the deserialization data to reduce dispatch
time.
* Integers in the snapshot were stored in a variable length
format that gives a compact representation for small positive
integers. This is still the case, but the new encoding can
be decoded without branches or conditional instructions,
which is faster on a modern CPU.
Review URL: https://chromiumcodereview.appspot.com/10918067
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12505 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Now with arm and x64 support. Additionally, added default unreachable case to switch statement in CompareIC::TargetState to make win and mac compilers happy.
Reviewer guide:
This is an exact copy of 10216 except:
src/arm/*
src/x64/*
src/ic.cc (added default case to swith in CompareIC::TargetState)
Review URL: http://codereview.chromium.org/8872060
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10219 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This includes specialcasing the generation when we know that the maps
of the two objects are the same. In addition, a new specialized
compare ic known objects cache is created.
The reason for the cache is that we need to have access to the stub
code from the roots; if we do not, the GC will collect the stub. In
this specialized case we use the map pointer as key in the cache, and
we always do a lookup before generating code. Actually hitting
something in the cache will happen very rarely, but we could
potentially overwrite an existing stub, which again will lead to the
GC collecting this old stub (even if it is referenced from other code
objects)
Review URL: http://codereview.chromium.org/8520006
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10216 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Original commit message:
Add a level of indirection to exception handler addresses.
To support deoptimization of exception handlers, the handler address in the
stack is converted to a pair of code object and an index into a separate
table of code offsets. The index part is invariant under deoptimization.
The index is packed into the handler state field so that handler size does
not change.
R=vegorov@chromium.org
BUG=
TEST=
Review URL: http://codereview.chromium.org/8538011
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9977 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
To support deoptimization of exception handlers, the handler address in the
stack is converted to a pair of code object and an index into a separate
table of code offsets. The index part is invariant under deoptimization.
The index is packed into the handler state field so that handler size does
not change.
R=vegorov@chromium.org,fschneider@chromium.org
BUG=
TEST=
Review URL: http://codereview.chromium.org/8462010
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9975 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
1) Don't make a call to C without having a valid frame on the stack.
2) Don't generate a call to a stub while generating a stub, unless we can be
sure that the stub we are calling has already been generated (the stub
generation code is not reentrant wrt. GC).
Review URL: http://codereview.chromium.org/7891042
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9297 ce2b1a6d-e550-0410-aec6-3dcde31c8c00