Port r12492 (479be376)
Original commit message:
This CL adds multiple things:
Transition arrays do not directly point at their descriptor array anymore, but rather do so via an indirect pointer (a JSGlobalPropertyCell).
An ownership bit is added to maps indicating whether it owns its own descriptor array or not.
Maps owning a descriptor array can pass on ownership if a transition from that map is generated; but only if the descriptor array stays exactly the same; or if a descriptor is added.
Maps that don't have ownership get ownership back if their direct child to which ownership was passed is cleared in ClearNonLiveTransitions.
To detect which descriptors in an array are valid, each map knows its own NumberOfOwnDescriptors. Since the descriptors are sorted in order of addition, if we search and find a descriptor with index bigger than this number, it is not valid for the given map.
We currently still build up an enumeration cache (although this may disappear). The enumeration cache is always built for the entire descriptor array, even if not all descriptors are owned by the map. Once a descriptor array has an enumeration cache for a given map; this invariant will always be true, even if the descriptor array was extended. The extended array will inherit the enumeration cache from the smaller descriptor array. If a map with more descriptors needs an enumeration cache, it's EnumLength will still be set to invalid, so it will have to recompute the enumeration cache. This new cache will also be valid for smaller maps since they have their own enumlength; and use this to loop over the cache. If the EnumLength is still invalid, but there is already a cache present that is big enough; we just initialize the EnumLength field for the map.
When we apply ClearNonLiveTransitions and descriptor ownership is passed back to a parent map, the descriptor array is trimmed in-place and resorted. At the same time, the enumeration cache is trimmed in-place.
Only transition arrays contain descriptor arrays. If we transition to a map and pass ownership of the descriptor array along, the child map will not store the descriptor array it owns. Rather its parent will keep the pointer. So for every leaf-map, we find the descriptor array by following the back pointer, reading out the transition array, and fetching the descriptor array from the JSGlobalPropertyCell. If a map has a transition array, we fetch it from there. If a map has undefined as its back-pointer and has no transition array; it is considered to have an empty descriptor array.
When we modify properties, we cannot share the descriptor array. To accommodate this, the child map will get its own transition array; even if there are not necessarily any transitions leaving from the child map. This is necessary since it's the only way to store its own descriptor array.
BUG=
TEST=
Review URL: https://chromiumcodereview.appspot.com/10918287
Patch from Akos Palfi <palfia@homejinni.com>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12549 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This CL adds multiple things:
Transition arrays do not directly point at their descriptor array anymore, but rather do so via an indirect pointer (a JSGlobalPropertyCell).
An ownership bit is added to maps indicating whether it owns its own descriptor array or not.
Maps owning a descriptor array can pass on ownership if a transition from that map is generated; but only if the descriptor array stays exactly the same; or if a descriptor is added.
Maps that don't have ownership get ownership back if their direct child to which ownership was passed is cleared in ClearNonLiveTransitions.
To detect which descriptors in an array are valid, each map knows its own NumberOfOwnDescriptors. Since the descriptors are sorted in order of addition, if we search and find a descriptor with index bigger than this number, it is not valid for the given map.
We currently still build up an enumeration cache (although this may disappear). The enumeration cache is always built for the entire descriptor array, even if not all descriptors are owned by the map. Once a descriptor array has an enumeration cache for a given map; this invariant will always be true, even if the descriptor array was extended. The extended array will inherit the enumeration cache from the smaller descriptor array. If a map with more descriptors needs an enumeration cache, it's EnumLength will still be set to invalid, so it will have to recompute the enumeration cache. This new cache will also be valid for smaller maps since they have their own enumlength; and use this to loop over the cache. If the EnumLength is still invalid, but there is already a cache present that is big enough; we just initialize the EnumLength field for the map.
When we apply ClearNonLiveTransitions and descriptor ownership is passed back to a parent map, the descriptor array is trimmed in-place and resorted. At the same time, the enumeration cache is trimmed in-place.
Only transition arrays contain descriptor arrays. If we transition to a map and pass ownership of the descriptor array along, the child map will not store the descriptor array it owns. Rather its parent will keep the pointer. So for every leaf-map, we find the descriptor array by following the back pointer, reading out the transition array, and fetching the descriptor array from the JSGlobalPropertyCell. If a map has a transition array, we fetch it from there. If a map has undefined as its back-pointer and has no transition array; it is considered to have an empty descriptor array.
When we modify properties, we cannot share the descriptor array. To accommodate this, the child map will get its own transition array; even if there are not necessarily any transitions leaving from the child map. This is necessary since it's the only way to store its own descriptor array.
Review URL: https://chromiumcodereview.appspot.com/10909007
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12492 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
in anticipation of the upcoming lexical global scope.
Mostly automatised as:
for FILE in `egrep -ril "global[ _]?context" src test/cctest`
do
echo $FILE
sed "s/Global context/Native context/g" <$FILE >$FILE.0
sed "s/global context/native context/g" <$FILE.0 >$FILE.1
sed "s/global_context/native_context/g" <$FILE.1 >$FILE.2
sed "s/GLOBAL_CONTEXT/NATIVE_CONTEXT/g" <$FILE.2 >$FILE.3
sed "s/GlobalContext/NativeContext/g" <$FILE.3 >$FILE
rm $FILE.[0-9]
done
R=mstarzinger@chromium.org
BUG=
TEST=
Review URL: https://chromiumcodereview.appspot.com/10832342
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12325 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Now a map points to a transition array which contains the descriptor array. The descriptor array is now immutable. The next step is to share the descriptor array with all back-pointed maps as long as there is a single line of extension. Maps that require a descriptor array but don't need transitions will still need a pseudo-empty transition array to contain the descriptor array.
Review URL: https://chromiumcodereview.appspot.com/10816005
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12298 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
regardless of the detected CPU. This is a requirement for the
debugger and the deoptimizer, which both expect that code from
the snapshot (compiled without VFP and ARM7) should have the
same layout as code compiled later.
This is another change to make snapshots more robust with
arbitrary code.
Review URL: https://chromiumcodereview.appspot.com/10824235
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12287 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The LastAdded points to the descriptor that was last added to the array. From the descriptor we can deduce the NextEnumerationIndex. This allows us to quickly find the property that we are transitioning to, which is necessary for transition-intensive code, eg JSON parsing.
Review URL: https://chromiumcodereview.appspot.com/10695120
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12042 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Only JSObject enumerables with enum cache (fast case properties, no interceptors, no enumerable properties on the prototype) are supported.
HLoadKeyedGeneric with keys produced by for-in enumeration are recognized and rewritten into direct property load by index. For this enum-cache was extended to store property indices in a separate array (see handles.cc).
New hydrogen instructions:
- HForInPrepareMap: checks for-in fast case preconditions and returns map that contains enum-cache;
- HForInCacheArray: extracts enum-cache array from the map;
- HCheckMapValue: map check with HValue map instead of immediate;
- HLoadFieldByIndex: load fast property by it's index, positive indexes denote in-object properties, negative - out of object properties;
Changed hydrogen instructions:
- HLoadKeyedFastElement: added hole check suppression for loads from internal FixedArrays that are knows to have no holes inside.
R=fschneider@chromium.org
BUG=
TEST=
Review URL: https://chromiumcodereview.appspot.com/9425045
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10794 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Loosen the requirement for Map equivalency on several map checks, including checks up the prototype chain, that are not sensitive to ElementsKinds. These selected map checks should also match against FAST_DOUBLE_ELEMENT and FAST_ELEMENT transitions of the original map. This specifically helps all variants of transitioned JSArrays to still efficiently call builtins like push, pop and sort.
BUG=none
TEST=none
Committed: http://code.google.com/p/v8/source/detail?r=10331
Review URL: http://codereview.chromium.org/9015020
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10356 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Loosen the requirement for Map equivalency on several map checks, including checks up the prototype chain, that are not sensitive to ElementsKinds. These selected map checks should also match against FAST_DOUBLE_ELEMENT and FAST_ELEMENT transitions of the original map. This specifically helps all variants of transitioned JSArrays to still efficiently call builtins like push, pop and sort.
BUG=none
TEST=none
Review URL: http://codereview.chromium.org/9015020
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10331 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
Use the BitField helper class for the code flags, so that we do not have to
define both a shift and a mask explicitly. This makes changing the flags
layout simpler.
Also, make the 'mask' and 'max' members of BitField into constants, because
they are constant and so that they can be used as constant expressions.
E.g., so they can be used in declaring other const members or in static
asserts.
R=fschneider@chromium.org
BUG=
TEST=
Review URL: http://codereview.chromium.org/7787028
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9232 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Remove the try/finally used for with and catch. Instead of using
try/finally to handle break and continue from with or catch,
statically track nesting dept and clean up when compiling break or
continue.
And instead of using try/finally to handle throw to handler in a frame
whose pc is inside a with or catch, store the context that the handler
should run in in the handler itself.
BUG=
TEST=
Review URL: http://codereview.chromium.org/7618007
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8922 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
C++'s 'great' idea of implicitly converting an enum to an integral value hit us
again, this time resulting in silly (but currently non-harmful) entries in the
relocation table. Encapsulated the AST ID recording a bit, which helped a lot to
find the culprit.
Review URL: http://codereview.chromium.org/7400016
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8671 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Before: every context cached the nearest enclosing function context. This
assumed that for nested contexts (i.e., with and catch contexts) the
enclosing function had a materialized link in the context chain.
Now: when necessary, we loop up the context chain to find such a context.
This enables catch contexts without forcing the enclosing function to
allocate its own context.
R=ager@chromium.org
BUG=
TEST=
Review URL: http://codereview.chromium.org/7230047
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8452 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This reverts r8381.
It was causing Mozilla test mozilla/ecma/Date/15.9.3.8-5 to fail and Sputnik tests S15.9.3.1_A5_T5, S15.9.3.1_A5_T1, S15.9.3.1_A5_T2, S15.9.3.1_A5_T4, S15.9.3.1_A5_T3 and S15.9.3.1_A5_T6 to timeout.
R=ager@chromium.org
BUG=none
TEST=mozilla/ecma/Date/15.9.3.8-5, S15.9.3.1_A5_T5, S15.9.3.1_A5_T1, S15.9.3.1_A5_T2, S15.9.3.1_A5_T4, S15.9.3.1_A5_T3 and S15.9.3.1_A5_T6
Review URL: http://codereview.chromium.org//7246004
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8397 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
