tells us that a map can transition to another map when we are generating
code for load operations. This may cause us to deopt if the same routine
is seeing different maps caused by branching in constructors. If so, I
have a different change that is around 100 times more complicated that
lets us generated Crankshaft code for negative lookups.
Review URL: https://chromiumcodereview.appspot.com/10306010
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11524 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
As a special case, for checks on index expressions with the form (expr + constant) if a smaller constant is checked later in the DT also eliminate the check.
Finally, if a larger constant is checked later in the same BB do the more general check (larger constant) earlier instead of the less general one.
This will not cause useless deoptimizations because, since we are in the same BB, all the checks would have been executed anyway.
BUG=
TEST=
Review URL: https://chromiumcodereview.appspot.com/10032029
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11437 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This change allows hydrogen instructions to keep track of instructions
that dominate certain side-effects (GVN flags) in the hydrogen graph. We
use the GVN pass to keep track of side-effects because accurate flags
are already in place.
It also adds a new side-effect (kChangesNewSpacePromotion) indicating
whether an instruction can cause a GC and have objects be promoted to
old-space. An object allocated in new-space is sure to stay on paths not
having said side-effect.
R=erik.corry@gmail.com
TEST=mjsunit/compiler/inline-construct
Review URL: https://chromiumcodereview.appspot.com/10031031
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11270 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This CL is a step towards removing ZoneObject's new operator without a Zone
parameter, which uses Isolate::Current. For e.g. the bulletben benchmark, this
CL reduces the number of calls to this new operator by roughly 120k, but we are
still left with 780k calls from other sites...
Review URL: https://chromiumcodereview.appspot.com/9487010
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10860 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
This extends the current support for nested object literals we already
have in Crankshaft, to also support nested array literals and mixed
nested literals containing arrays and objects. All three types are
generated by the unified HFastLiteral instruction.
All previous upper bounds on nested literal graphs remain unchanged,
keeping the size of generated code in check.
The main intention is to boost performance of two-dimensional array
literals containing constant elements (aka. matrices).
R=danno@chromium.org
TEST=mjsunit/compiler/literals-optimized
Review URL: https://chromiumcodereview.appspot.com/9403018
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10734 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Yak shaving for map sharing with accessor properties contd.: When CALLBACKS can
have map transitions, simply looking at the property type is not sufficient
anymore to decide if a property is there or not. One has to look at the actual
contents of the descriptor entry then, but this breaks down sometimes when the
lookup is being done with a NULL holder. Luckily enough, we can oftren replace
IsProperty by the simpler IsFound, because we inspect the type immediately
afterwards, anyway.
Review URL: https://chromiumcodereview.appspot.com/9280007
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10474 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This generates optimized code for deep-copying of nested object literal
boilerplates which are statically known. Most of the boilerplates have
already been generated at crankshaft time, so this optimization should
kick in for virtually every object literal. Only nested object literal
graphs up to a certain depth and containing up to a certain total number
of properties are considered for this optimization. This will prevent
explosion of code size due to large object literals (e.g. eval on JSON).
Improves splay performance because object literals are created often.
R=fschneider@chromium.org
Review URL: http://codereview.chromium.org/8640001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10061 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This time, we initially leave the HTypeof instruction in the Hydrogen graph,
even for the special cases. We later try to remove this instruction (and any
HConstant) in the canonicalization pass, if possible. Always removing the
HTypeof during the initial graph construction is wrong if e.g. it is used in an
HSimulate.
The removals can be generalized a bit, but this will happen in a separate CL.
TEST=mjsunit/optimized-typeof.js
Review URL: http://codereview.chromium.org/8334021
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9688 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
