Commit Graph

1960 Commits

Author SHA1 Message Date
jgruber
8df547d402 [regexp] Avoid unneeded accesses to lastIndex
This implements https://github.com/tc39/ecma262/pull/627/.

BUG=v8:5360

Review-Url: https://codereview.chromium.org/2339443002
Cr-Commit-Position: refs/heads/master@{#39402}
2016-09-14 07:39:44 +00:00
mstarzinger
85289749f4 [interpreter] Add regression test for bogus OSR entry.
This adds a regression test for a bug where {OsrPoll} instructions
within the bytecode stream ended up outside of actual loops. This has
been fixed already, by merging {OsrPoll} into the backwards branch.

R=rmcilroy@chromium.org
TEST=mjsunit/regress/regress-crbug-645888
BUG=chromium:645888

Review-Url: https://codereview.chromium.org/2337033002
Cr-Commit-Position: refs/heads/master@{#39385}
2016-09-13 13:23:21 +00:00
mvstanton
2ab3fcf42f Record call counts also for megamorphic calls.
To make better inlining decisions, it's good to have call counts for poly/mega-morphic cases. This CL makes it work for calls, and another will follow to better unify the code between constructor calls and normal calls (and thence, to record megamorphic call counts there as well).

BUG=

Review-Url: https://codereview.chromium.org/2325083003
Cr-Commit-Position: refs/heads/master@{#39377}
2016-09-13 11:04:22 +00:00
cbruni
621f4af720 [elements] Handlify SloppyArguments IndexOfValueImpl
The raw pointer to the parameter_map might get stale in case of accessors present on
the arguments object.
Drive-by-fix: use nullptr instead of the_hole with isolate access.

BUG=chromium:645680

Review-Url: https://codereview.chromium.org/2332503002
Cr-Commit-Position: refs/heads/master@{#39359}
2016-09-12 17:32:09 +00:00
adamk
58325e616d [turbofan] Switch from a whitelist to a blacklist for NeedsFrameStateInput
The whitelist is populated with those inline intrinsics that are lowered
in JSIntrinsicInlining and were not previously blacklisted. Thus the only
additional FrameStates this CL adds are those where the caller tries to
call the INLINE version of an intrinsic but ends up calling the RUNTIME
version instead.

R=bmeurer@chromium.org
BUG=chromium:644631

Review-Url: https://codereview.chromium.org/2331543002
Cr-Commit-Position: refs/heads/master@{#39357}
2016-09-12 16:12:57 +00:00
mstarzinger
0681deb914 [interpreter] Fix destroyed new.target register use.
This fixes a corner-case where the bytecode was using the <new.target>
register directly without going through the local variable. The value
might be clobbered because the deoptimizer doesn't properly restore the
value. The label will causes bytecode pipeline to be flushed and hence
ensure {BytecodeRegisterOptimizer} doesn't reuse <new.target> anymore.

R=rmcilroy@chromium.org
TEST=mjsunit/regress/regress-crbug-645103
BUG=chromium:645103

Review-Url: https://codereview.chromium.org/2325133002
Cr-Commit-Position: refs/heads/master@{#39306}
2016-09-09 12:20:20 +00:00
adamk
e4273007b6 Properly handle holes following spreads in array literals
Before this change, the spread desugaring would naively call
`%AppendElement($R, the_hole)` and in some cases $R would have
a non-holey elements kind, putting the array into the bad state
of exposing holes to author code.

This patch avoids calling %AppendElement with a hole, instead
simply incrementing $R.length when it sees a hole in the literal
(this is safe because $R is known to be an Array). The existing
logic for elements transitions takes care of giving the array a
holey ElementsKind.

BUG=chromium:644215

Review-Url: https://codereview.chromium.org/2321533003
Cr-Commit-Position: refs/heads/master@{#39294}
2016-09-08 18:50:41 +00:00
mstarzinger
9984d6f689 [deoptimizer] Support materialization of ContextExtension.
This adds support to the deoptimizer to materialize ContextExtension
objects that have been de-materialized by escape analysis. This is
follow-up to the inline allocation of such objects during the create
lowering phase (i.e. JSCreateWithContext and JSCreateCatchContext).

R=bmeurer@chromium.org
TEST=mjsunit/regress/regress-crbug-644245
BUG=chromium:644245

Review-Url: https://codereview.chromium.org/2317353003
Cr-Commit-Position: refs/heads/master@{#39270}
2016-09-08 10:33:20 +00:00
bmeurer
4ed27fc836 [turbofan] Ensure that all prototypes are stable for push/pop.
When lowering Array.prototype.push/.pop to the fast inlined version, we
first need to ensure that all prototypes (including the Object.prototype)
are stable.

R=mvstanton@chromium.org
BUG=chromium:644689

Review-Url: https://codereview.chromium.org/2319533005
Cr-Commit-Position: refs/heads/master@{#39266}
2016-09-08 08:48:32 +00:00
bmeurer
91ed540ee6 [turbofan] Revert "Avoid overflow checks on SpeculativeNumberAdd/Subtract/Multiply."
The optimization is not correct for unsigned output types, and we the
overall complexity seems too high. We need to find a better way to
take into account the input/output type restrictions.

Also added a regression test for the unsigned output bug.

BUG=v8:5267,v8:5270,v8:5357
TBR=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2320013002
Cr-Commit-Position: refs/heads/master@{#39262}
2016-09-08 04:20:31 +00:00
lpy
7a38b927c8 Reland - Allow lexically declared "arguments" in function scope in sloppy mode.
Lexically declared "arguments" in sloppy mode will throw redeclaration error
currently, this patch fixes it by delaying the declaration of arguments until we
fully parse parameter list and function body.

BUG=v8:4577
LOG=N

Committed: https://crrev.com/70a613dd0a5f5d205b46559b55702764464851fa
Review-Url: https://codereview.chromium.org/2290753003
Cr-Original-Commit-Position: refs/heads/master@{#39109}
Cr-Commit-Position: refs/heads/master@{#39230}
2016-09-07 06:54:54 +00:00
mstarzinger
553d504923 [turbofan] Handle ObjectIsReceiver in escape analysis.
This adds handling of {IrOpcode::kObjectIsReceiver} nodes to the escape
status analysis. Such uses are treated as escaping for now until we add
dedicated handling to the escape analysis reducer.

R=bmeurer@chromium.org
TEST=mjsunit/regress/regress-crbug-631027
BUG=chromium:631027

Review-Url: https://codereview.chromium.org/2317623003
Cr-Commit-Position: refs/heads/master@{#39205}
2016-09-06 11:59:31 +00:00
rmcilroy
c950256013 [Turbofan] Fix CallSuper argument order in BytecodeGraphBuilder.
The constructor and new.target arguments were passed to CallConstruct in
the wrong order by BytecodeGraphBuilder, which caused subclassing to be
incorrect when optimizing from bytecode.

Also clean up some unecessary functions in interpreter.cc found while
figuring this out.

BUG=chromium:642409

Review-Url: https://codereview.chromium.org/2312103002
Cr-Commit-Position: refs/heads/master@{#39204}
2016-09-06 11:53:19 +00:00
mstarzinger
cc1249b779 [compiler] Bytecode preparation fails for asm.js modules.
This handles the case where preparation of bytecode might fail inside
Compiler::EnsureBytecode due to the underlying function being a fully
validated asm.js module. We simply bailout of bytecode preparation.

R=bradnelson@chromium.org
TEST=mjsunit/regress/regress-crbug-644111
BUG=chromium:644111

Review-Url: https://codereview.chromium.org/2309853002
Cr-Commit-Position: refs/heads/master@{#39187}
2016-09-05 23:03:07 +00:00
jgruber
64c518d06d Do not include Error.captureStackTrace in the trace
BUG=v8:5342

Review-Url: https://codereview.chromium.org/2307783002
Cr-Commit-Position: refs/heads/master@{#39124}
2016-09-02 09:51:42 +00:00
bmeurer
86af343749 [test] Add regression test for http://crbug.com/642056.
The bug itself was already fixed in ToT as part of
http://crrev.com/2263273003.

R=machenbach@chromium.org
BUG=chromium:642056

Review-Url: https://codereview.chromium.org/2306913002
Cr-Commit-Position: refs/heads/master@{#39117}
2016-09-02 07:08:29 +00:00
machenbach
d67fedb12c Revert of Allow lexically declared "arguments" in function scope in sloppy mode. (patchset #5 id:100001 of https://codereview.chromium.org/2290753003/ )
Reason for revert:
Breaks layout tests:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/9470

Original issue's description:
> Allow lexically declared "arguments" in function scope in sloppy mode.
>
> Lexically declared "arguments" in sloppy mode will throw redeclaration error
> currently, this patch fixes it by delaying the declaration of arguments until we
> fully parse parameter list and function body.
>
> BUG=v8:4577
> LOG=N
>
> Committed: https://crrev.com/70a613dd0a5f5d205b46559b55702764464851fa
> Cr-Commit-Position: refs/heads/master@{#39109}

TBR=adamk@chromium.org,mythria@chromium.org,lpy@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4577

Review-Url: https://codereview.chromium.org/2304853002
Cr-Commit-Position: refs/heads/master@{#39115}
2016-09-02 06:23:57 +00:00
lpy
70a613dd0a Allow lexically declared "arguments" in function scope in sloppy mode.
Lexically declared "arguments" in sloppy mode will throw redeclaration error
currently, this patch fixes it by delaying the declaration of arguments until we
fully parse parameter list and function body.

BUG=v8:4577
LOG=N

Review-Url: https://codereview.chromium.org/2290753003
Cr-Commit-Position: refs/heads/master@{#39109}
2016-09-01 22:10:34 +00:00
bmeurer
432790c92c [turbofan] Only check semantic axis for Type::None.
R=jarin@chromium.org
BUG=chromium:643073

Review-Url: https://codereview.chromium.org/2299903002
Cr-Commit-Position: refs/heads/master@{#39065}
2016-09-01 07:11:21 +00:00
bmeurer
64a7bd3877 [turbofan] Don't treat the hole NaN as constant inside the compiler.
We use a signaling NaN to represent the hole in
FAST_HOLEY_DOUBLE_ELEMENTS backing stores, but on Intel processors, the
C++ compiler may decide to (or be forced to due to calling conventions)
use X87 registers for double values. However transfering to X87
registers automatically quietens the NaNs and there's no way to disable
this. Therefore we should just always load the hole NaN from the canonical
place identified by the address_of_hole_nan external reference instead,
which might even be more efficient in some cases.

R=jarin@chromium.org, jkummerow@chromium.org
BUG=v8:5332

Review-Url: https://codereview.chromium.org/2303643002
Cr-Commit-Position: refs/heads/master@{#39062}
2016-09-01 06:02:19 +00:00
bmeurer
7b79224b21 [crankshaft] Disable further folding already folded allocations.
When we try to further fold previously folded allocations in Crankshaft
GVN we don't properly transform the allocations involved, which causes
the mechanism to leave holes in the new/old space (and thereby violate
the iterability property of the new/old space).

BUG=chromium:621868
R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2297983003
Cr-Commit-Position: refs/heads/master@{#39040}
2016-08-31 09:48:45 +00:00
bmeurer
864cdc124c [test] Speed-up regression test for growing stores.
TBR=machenbach@chromium.org
BUG=chromium:635798,chromium:638295

Review-Url: https://codereview.chromium.org/2288813003
Cr-Commit-Position: refs/heads/master@{#38991}
2016-08-30 04:04:32 +00:00
littledan
5af4cd9840 Disallow tail calls from async functions and generators
Tail calls don't make sense from async functions and generators, as
each activation of these functions needs to make a new, distnict,
non-reused generator object. These tail calls are not required per
spec. This patch disables both syntactic and implicit tail calls
in async functions and generators.

R=neis
BUG=v8:5301,chromium:639270

Review-Url: https://codereview.chromium.org/2278413003
Cr-Commit-Position: refs/heads/master@{#38986}
2016-08-29 18:31:35 +00:00
mstarzinger
b52aecac7e [compiler] Make Compiler::EnsureBytecode not switch tiers.
This preserves the original shared code of the underlying function when
bytecode is provided. The method in question should only ensure bytecode
is present, but should avoid switching compilation tiers of the given
function. It might be that the function was fast-tracked to baseline by
inlining without going through the interpreted tier first.

R=rmcilroy@chromium.org
TEST=mjsunit/regress/regress-crbug-635923
BUG=chromium:635923

Review-Url: https://codereview.chromium.org/2278543002
Cr-Commit-Position: refs/heads/master@{#38866}
2016-08-24 14:09:59 +00:00
bmeurer
6646d73b6f [turbofan] Use ObjectIsReceiver directly for inlining.
Don't bother using %_IsJSReceiver, which immediately gets lowered to
ObjectIsReceiver anyways (by the JSIntrinsicLowering), but requires
some complicated rewiring of effect/control chains.

R=mstarzinger@chromium.org
BUG=chromium:640369

Review-Url: https://codereview.chromium.org/2271973003
Cr-Commit-Position: refs/heads/master@{#38864}
2016-08-24 11:09:32 +00:00
bradnelson
e5f5ac7d2b [wasm] asm.js - Remove Wasm.instantiateModuleFromAsm, use asm.js directly.
Make use of %IsAsmWasmCode in place of Wasm.instantiateModuleFromAsm,
in order to reduce the surface area of the Wasm object,
and to focus on testing asm.js coming in via the parser.

Ignore extra CONST_LEGACY assignment introduced by the parser
when modules have the form:
(function Foo(a, b, c) {..});
This requires both a validator and AsmWasmBuilder change.

Move stdlib use collection to import time,
to reject modules that import a function, even if not used.

BUG= https://bugs.chromium.org/p/v8/issues/detail?id=4203
LOG=N
R=jpp@chromium.org,titzer@chromium.org

Review-Url: https://codereview.chromium.org/2264913002
Cr-Commit-Position: refs/heads/master@{#38806}
2016-08-23 04:07:23 +00:00
bradnelson
561bfcb70d [wasm] asm.js - Check stdlib.NaN is valid, prepare for the rest.
Record which asm.js stdlib members are used and add a check that NaN is actually correctly set. Other stdlib members to be added in a later change.

Also add a stdlib argument to Wasm.instantiateModuleFromAsm, in preparation for that function to be replaced by normal asm.js instantiation.

BUG= https://bugs.chromium.org/p/v8/issues/detail?id=4203
LOG=N
R=jpp@chromium.org,titzer@chromium.org

Review-Url: https://codereview.chromium.org/2251433002
Cr-Commit-Position: refs/heads/master@{#38760}
2016-08-19 18:26:24 +00:00
mstarzinger
8ab555cc15 [interpreter] Fix canonicalization when preserving bytecode.
This fixes canonicalization of {SharedFunctionInfo} objects in the
{Compiler::GetSharedFunctionInfo} method when bytecode is preserved.
Eager compilation is only triggered when no code is present.

R=rmcilroy@chromium.org
TEST=mjsunit/regress/regress-crbug-638551
BUG=chromium:638551

Review-Url: https://codereview.chromium.org/2245263006
Cr-Commit-Position: refs/heads/master@{#38709}
2016-08-18 10:42:40 +00:00
rmcilroy
477495c886 [Parser] Track ContainsDot for SMI values.
Ensures SMI values have SMI type even if they have a dot (e.g., 1.0).
Adds SMI_WITH_DOT type to maintain this.

BUG=chromium:638134

Review-Url: https://codereview.chromium.org/2248693005
Cr-Commit-Position: refs/heads/master@{#38698}
2016-08-18 08:15:43 +00:00
bmeurer
665f0e4020 [turbofan] Fix CheckedInt32Mod lowering for -0 case with negative left hand side.
Properly deoptimize if the left hand side of a CheckedInt32Mod is
negative and the result of the operation is zero.

R=jarin@chromium.org
BUG=v8:5286

Review-Url: https://codereview.chromium.org/2243803002
Cr-Commit-Position: refs/heads/master@{#38615}
2016-08-12 12:13:51 +00:00
jgruber
d252808011 Handle missing context when getting frame details
This bug was triggered by a very specific combination:

* A context-allocated variable at script scope.
* OSR optimization.
* A scheduled breakpoint, which triggers at stack checks.

Stack checks differ from other possible breakpoint locations in that
the context (among other things) may be in a register and not on the
stack, making it impossible to recover during deoptimization. The
frame_inspector then returns undefined when asked for the context.

In GetFrameDetails, handle this case by omitting all context-allocated
variables.

BUG=v8:5279

Review-Url: https://codereview.chromium.org/2245603002
Cr-Commit-Position: refs/heads/master@{#38611}
2016-08-12 11:20:19 +00:00
bmeurer
7060bab81c [turbofan] Properly guard keyed stores wrt. setters in the prototype chain.
For holey/growing keyed stores, we need to check that there are no
setters in the prototype chain and protect against changes to that
via code dependencies.

R=verwaest@chromium.org
BUG=v8:5275,v8:5276

Review-Url: https://codereview.chromium.org/2231683002
Cr-Commit-Position: refs/heads/master@{#38514}
2016-08-10 06:30:22 +00:00
bmeurer
78727d4362 [runtime] %GrowArrayElements doesn't have a native context in TurboFan.
When we compile a growing store in TurboFan, we don't pass a (native)
context to the %GrowArrayElements fallback function, as the whole logic
is actually context independent. However, that means that we need to
bailout early in case the object is a prototype, which requires context
dependent checks in the array protector code.

R=cbruni@chromium.org
BUG=chromium:635798

Review-Url: https://codereview.chromium.org/2224253003
Cr-Commit-Position: refs/heads/master@{#38491}
2016-08-09 13:03:07 +00:00
rmcilroy
c1ae15d930 [Interpreter] Don't try to create bytecode array if HasStackOverflow().
BUG=chromium:635429

Review-Url: https://codereview.chromium.org/2228503004
Cr-Commit-Position: refs/heads/master@{#38474}
2016-08-09 07:24:13 +00:00
hpayer
caf5c5a194 [heap] Use smaller minimum allocation limit growing step when optimizing for memory usage.
BUG=chromium:634900

Review-Url: https://codereview.chromium.org/2223493002
Cr-Commit-Position: refs/heads/master@{#38435}
2016-08-08 11:32:01 +00:00
mstarzinger
f00b42ae31 [interpreter] Fix profiler when hitting OSR frame.
This fixes the runtime profiler to no longer assume that seeing an
optimized frame on the stack implies the underlying function is not
being interpreted when entered normally. This no longer holds with code
generated for OSR directly from bytecode (not installed on function).

R=rmcilroy@chromium.org
TEST=mjsunit/regress/regress-crbug-632800
BUG=chromium:632800

Review-Url: https://codereview.chromium.org/2208603005
Cr-Commit-Position: refs/heads/master@{#38360}
2016-08-05 08:47:48 +00:00
mstarzinger
5671b663f9 [interpreter] Avoid tier-up when there is an OSR activation.
This makes sure we prevent a tier-up for function which also have an
optimized activation of OSR code on the stack. In case the OSR code
deoptimizes, it needs the bytecode to still be around.

R=rmcilroy@chromium.org
TEST=mjsunit/regress/regress-5262
BUG=v8:5262

Review-Url: https://codereview.chromium.org/2206363004
Cr-Commit-Position: refs/heads/master@{#38359}
2016-08-05 07:55:03 +00:00
yangguo
771b81f806 [debug] fix exception prediction for asm frames.
R=mstarzinger@chromium.org
BUG=chromium:633999

Review-Url: https://codereview.chromium.org/2215713002
Cr-Commit-Position: refs/heads/master@{#38358}
2016-08-05 07:14:21 +00:00
bmeurer
cad5b29610 [turbofan] Remove unnecessary prototype checks for element access.
We don't need to add stability dependencies on JSObject prototypes when
storing to an element, because we do the map check (and thereby guard
the elements kind) and we also properly deoptimize on holes if the array
protector is not usable.

R=verwaest@chromium.org
BUG=chromium:616709

Review-Url: https://codereview.chromium.org/2198833002
Cr-Commit-Position: refs/heads/master@{#38355}
2016-08-05 04:55:03 +00:00
adamk
e6d2c9b584 Properly pass InitializationFlag back from ScriptContextTable lookups
This was dropped accidentally in bb97d27ab.

R=verwaest@chromium.org
BUG=chromium:633884

Review-Url: https://codereview.chromium.org/2203213003
Cr-Commit-Position: refs/heads/master@{#38345}
2016-08-04 16:13:41 +00:00
mstarzinger
667d8ad099 [turbofan] Fix missing bailout for accessors in literals.
This adds the missing lazy bailout point when defining accessor pairs
within object literals via Runtime::kDefineAccessorPropertyUnchecked.
The runtime function in question can indeed trigger a lazy deopt due
to a DependentCode::kPrototypeCheckGroup dependency.

R=bmeurer@chromium.org
TEST=mjsunit/regress/regress-crbug-633585
BUG=chromium:633585

Review-Url: https://codereview.chromium.org/2207413002
Cr-Commit-Position: refs/heads/master@{#38336}
2016-08-04 10:28:46 +00:00
jgruber
ea6b9609a6 Handle stack overflows in NoSideEffectToString
An infinite recursion can be triggered when NoSideEffectToString is
called on an error object with its name property set to itself.

BUG=633998

Review-Url: https://codereview.chromium.org/2206313002
Cr-Commit-Position: refs/heads/master@{#38325}
2016-08-04 07:45:11 +00:00
rmcilroy
aacbdacb89 [Crankshaft] Move don't crankshaft check before EnsureDeoptimizationSupport.
Avoids compiling baseline code when the function isn't able to be
optimized by crankshaft.

BUG=chromium:632289

Review-Url: https://codereview.chromium.org/2194453002
Cr-Commit-Position: refs/heads/master@{#38304}
2016-08-03 15:02:38 +00:00
jgruber
d48170dbf5 Move NoSideEffectToString to C++
BUG=

Review-Url: https://codereview.chromium.org/2206573002
Cr-Commit-Position: refs/heads/master@{#38289}
2016-08-03 12:22:23 +00:00
bmeurer
c9324fe6c5 [turbofan] Fix invalid representation selection for Phis/Selects.
We cannot just blindly make a representation selection for Phi or Select
based on the truncations, but we also need to consider the type of the
inputs (or actually of the Phi/Select node itself). We can only use
Word32 representation based on Word32 truncation if the inputs are
Number or Oddball, same for Float64.

R=epertoso@chromium.org
BUG=v8:5255

Review-Url: https://codereview.chromium.org/2206553002
Cr-Commit-Position: refs/heads/master@{#38241}
2016-08-02 12:11:09 +00:00
mstarzinger
962fd4ae4b [interpreter] Elide OSR polling from fake loops.
This makes sure we are not inserting {OsrPoll} instructions for any
statements that are not actually loops and have no back edges. Without
back edges the {BytecodeGraphBuilder} is unable to deduce loop ranges
and hence cannot construct a graph for OSR entry.

R=neis@chromium.org
TEST=mjsunit/regress/regress-5252
BUG=v8:5252

Review-Url: https://codereview.chromium.org/2200733002
Cr-Commit-Position: refs/heads/master@{#38233}
2016-08-02 09:16:59 +00:00
bmeurer
a758144329 [turbofan] Fix invalid comparison operator narrowing.
When we narrow a signed32 comparison to uint8 or uint16 representation,
we also need to change the condition to unsigned comparisons otherwise
the comparison will be done on int16/int8 which interprets the narrowed
bits wrong.

R=epertoso@chromium.org
BUG=v8:5254

Review-Url: https://codereview.chromium.org/2202803003
Cr-Commit-Position: refs/heads/master@{#38231}
2016-08-02 07:46:15 +00:00
jgruber
061d082dd3 Properly set function index in CallSite constructor
BUG=632965
R=yangguo@chromium.org

Review-Url: https://codereview.chromium.org/2199673002
Cr-Commit-Position: refs/heads/master@{#38208}
2016-08-01 12:59:57 +00:00
jgruber
1c7c0521f1 Set Error.stack property writable
Previously, the stack property was set up in JS as read-only; but since
it had a JS setter, writability was ignored and writing to stack was
possible.

This is no longer the case now that stack is either an actual data
property, or is associated with C++ accessors. Explicitly set the
property as writable to preserve old behavior.

BUG=5245
R=yangguo@chromium.org

Review-Url: https://codereview.chromium.org/2190313002
Cr-Commit-Position: refs/heads/master@{#38158}
2016-07-29 08:15:26 +00:00
ishell
fc66694de8 [fullcode][mips][mips64][ppc][s390] Avoid trashing of a home object when doing a count operation with keyed load/store to a super.
BUG=chromium:631917

Review-Url: https://codereview.chromium.org/2191663004
Cr-Commit-Position: refs/heads/master@{#38139}
2016-07-28 14:31:07 +00:00