Commit Graph

13603 Commits

Author SHA1 Message Date
rmcilroy
ed7bef5b91 [Interpreter] Optimize the Register Optimizer.
Modify the Bytecode Register Optimizer to be an independent component
rather than part of the BytecodePipeline. This means the BytecodeArrayBuilder
can explicitly call it with register operands when outputting a bytecode
and the Bytecode Register Optimizer doesn't need to work out which operands
are register operands. This also means we don't need to build BytecodeNodes
for Ldar / Star / Mov bytecodes unless they are actually emitted by the
optimizer.

This change also modifies the way the BytecodeArrayBuilder converts
operands to make use of the OperandTypes specified in bytecodes.h.
This avoids having to individually convert operands to their raw output
value before calling Output(...).

BUG=v8:4280

Review-Url: https://codereview.chromium.org/2393683004
Cr-Commit-Position: refs/heads/master@{#40543}
2016-10-24 20:47:53 +00:00
verwaest
caba112d03 Simplify and fix the rewriter
Now we
- always set .result to undefined before a visited loop and switch since we can't know whether they will set a value,
- only visit finally if it can break/continue; and only store/restore .result in that case

BUG=

Review-Url: https://codereview.chromium.org/2427253003
Cr-Commit-Position: refs/heads/master@{#40542}
2016-10-24 19:23:03 +00:00
rmcilroy
381b5437b2 Don't call FastNewFunctionContextStub if context is bigger than kMaxRegularHeapObjectSize.
CL https://codereview.chromium.org/2177273002 changed FastNewFunctionContextStub
to take a number of slots parameter and in-doing so removed the maximum slot
count for FastNewFunctionContextStub. This made it possible to create a
closure which is larger than kMaxRegularHeapObjectSize and so can't be
allocated by FastNewFunctionContextStub.

Reintroduce FastNewFunctionContextStub::kMaxSlots (but make the limit much
larger) to ensure we call the runtime for contexts which need to be
allocated in the LO space.

BUG=chromium:655573

Review-Url: https://codereview.chromium.org/2445703002
Cr-Commit-Position: refs/heads/master@{#40541}
2016-10-24 17:23:21 +00:00
neis
3107fd0788 [modules] Update test262.status after test262 upstream fix.
R=littledan@chromium.org,adamk@chromium.org
BUG=v8:1569

Review-Url: https://codereview.chromium.org/2440103002
Cr-Commit-Position: refs/heads/master@{#40537}
2016-10-24 15:49:29 +00:00
mstarzinger
6dd0587be3 Revert of [compiler] Prepare for partially shipping Ignition. (patchset #1 id:1 of https://codereview.chromium.org/2443573002/ )
Reason for revert:
Causes regressions: https://bugs.chromium.org/p/chromium/issues/detail?id=658711

Original issue's description:
> [compiler] Prepare for partially shipping Ignition.
>
> This prepares the code-base so that Ignition can be enabled on a certain
> subset of compilations without setting the {FLAG_ignition} flag (which
> enables Ignition on all compilations). We should not check the flag in
> question explicitly anywhere outside of the compiler heuristics.
>
> R=mvstanton@chromium.org

BUG=chromium:658711
TBR=mvstanton@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.

Review-Url: https://codereview.chromium.org/2448443002
Cr-Commit-Position: refs/heads/master@{#40534}
2016-10-24 13:02:29 +00:00
ahaas
cc448ff0f0 [wasm] Cleanup the wasm-call fuzzer
I committed https://codereview.chromium.org/2447643002 prematurely, this
is a cleanup.

R=titzer@chromium.org

Review-Url: https://codereview.chromium.org/2444863002
Cr-Commit-Position: refs/heads/master@{#40533}
2016-10-24 12:44:03 +00:00
jgruber
ae3357d216 [regexp] Move RegExp.prototype.test to TF
This results in a speedup of around 2x. RegExpExec is also ported in
this CL.

BUG=v8:5339

Review-Url: https://codereview.chromium.org/2441993002
Cr-Commit-Position: refs/heads/master@{#40532}
2016-10-24 12:41:29 +00:00
ahaas
f8414ead48 [wasm] Add a new fuzzer which can also test wasm function calls.
Depending on the inputs the fuzzer creates multiple functions. These
functions can have signatures with an int32 return value and up to three
parameters of type int32, int64, float32, or float64.

R=titzer@chromium.org, clemensh@chromium.org

Review-Url: https://codereview.chromium.org/2447643002
Cr-Commit-Position: refs/heads/master@{#40530}
2016-10-24 11:15:00 +00:00
yangguo
8971b6b6c3 [inspector] conditionally copy files for inspector test.
R=machenbach@chromium.org

Review-Url: https://codereview.chromium.org/2424313004
Cr-Commit-Position: refs/heads/master@{#40528}
2016-10-24 10:57:37 +00:00
jgruber
f87d73c7cf [regexp] Add regression test for v8:5434
The test ensures that in RegExp.prototype[@@split], exec is neither
accessed too early nor too often.

BUG=v8:5339,v8:5434

Review-Url: https://codereview.chromium.org/2440413002
Cr-Commit-Position: refs/heads/master@{#40526}
2016-10-24 10:39:01 +00:00
bmeurer
6c5fa8b49e [turbofan] Fix deopt loop in out-of-bounds string element access.
We need to check the KeyedLoadIC state to guard against potential
deoptimization loops due to out-of-bounds accesses, because the IC
system uses the MEGAMORPHIC state to also signal that there was an
out-of-bounds access already.

R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2443893002
Cr-Commit-Position: refs/heads/master@{#40525}
2016-10-24 10:32:36 +00:00
ulan
ad815a7b9a [heap] Refactor marking deque.
This patch moves management of marking deque backing store into the
MarkingDeque class, which will simplify unmapping of backing store in
concurrent task.

BUG=

Review-Url: https://codereview.chromium.org/2439063002
Cr-Commit-Position: refs/heads/master@{#40523}
2016-10-24 09:07:28 +00:00
bmeurer
a58d7907ea [turbofan] Fix typed lowering of JSToLength.
When lowering JSToLength, we cannot just smash arbitrary bounds on the
Select nodes, as that will confuse the representation selection later.
Instead properly rename the input using NumberMax and NumberMin.

R=jarin@chromium.org
BUG=chromium:657478

Review-Url: https://codereview.chromium.org/2440333002
Cr-Commit-Position: refs/heads/master@{#40519}
2016-10-24 06:37:22 +00:00
mtrofin
91a5a219d4 [wasm] Avoid double-serializing the wire bytes
Since the public API for deserialization is now just DeserializeOrCompile,
we can trickle down the wire bytes to the deserialization logic, and
avoid the need for duplicating the wire bytes when serializing.

BUG=chromium:657316

Review-Url: https://chromiumcodereview.appspot.com/2433273002
Cr-Commit-Position: refs/heads/master@{#40516}
2016-10-22 15:15:04 +00:00
titzer
71b63a95fa [wasm] Enable all WASM tests (experiment).
R=bradnelson@chromium.org
BUG=

Review-Url: https://chromiumcodereview.appspot.com/2436953004
Cr-Commit-Position: refs/heads/master@{#40513}
2016-10-21 18:16:11 +00:00
neis
cadfe092a2 [modules] Fix bugs in assignments to exported variables.
- Add hole check if needed.
- Preserve the accumulator so that the result is the rhs.

R=adamk@chromium.org
BUG=v8:1569,v8:5547

Review-Url: https://chromiumcodereview.appspot.com/2438653003
Cr-Commit-Position: refs/heads/master@{#40510}
2016-10-21 14:24:31 +00:00
mstarzinger
e31e5e91a5 [compiler] Prepare for partially shipping Ignition.
This prepares the code-base so that Ignition can be enabled on a certain
subset of compilations without setting the {FLAG_ignition} flag (which
enables Ignition on all compilations). We should not check the flag in
question explicitly anywhere outside of the compiler heuristics.

R=mvstanton@chromium.org

Review-Url: https://chromiumcodereview.appspot.com/2443573002
Cr-Commit-Position: refs/heads/master@{#40507}
2016-10-21 13:14:28 +00:00
jgruber
eb10dc4c91 [regexp] Use consistent map checks for fast paths
These map checks were implemented for TF code already. This CL makes
sure that parts implemented in C++ follow the same logic, which is:

An object is an unmodified regexp if:
1) it's a receiver,
2) its map is the initial regexp map,
3) its prototype is a receiver,
4) and its prototype's map is the initial prototype's initial map.

We can now be smarter in @@replace and @@split since checking maps
(unlike the previous check of RegExp.prototype.exec) is not observable,
so we can perform fast-path checks at a time of our choosing.

BUG=v8:5339,v8:5434,v8:5123

Review-Url: https://chromiumcodereview.appspot.com/2434983002
Cr-Commit-Position: refs/heads/master@{#40501}
2016-10-21 11:58:50 +00:00
machenbach
0b7e35ff16 Revert of [regexp] Use consistent map checks for fast paths (patchset #7 id:120001 of https://chromiumcodereview.appspot.com/2434983002/ )
Reason for revert:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/10853

Original issue's description:
> [regexp] Use consistent map checks for fast paths
>
> These map checks were implemented for TF code already. This CL makes
> sure that parts implemented in C++ follow the same logic, which is:
>
> An object is an unmodified regexp if:
> 1) it's a receiver,
> 2) its map is the initial regexp map,
> 3) its prototype is a receiver,
> 4) and its prototype's map is the initial prototype's initial map.
>
> We can now be smarter in @@replace and @@split since checking maps
> (unlike the previous check of RegExp.prototype.exec) is not observable,
> so we can perform fast-path checks at a time of our choosing.
>
> BUG=v8:5339,v8:5434,v8:5123

TBR=yangguo@chromium.org,jgruber@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5339,v8:5434,v8:5123

Review-Url: https://chromiumcodereview.appspot.com/2438283002
Cr-Commit-Position: refs/heads/master@{#40499}
2016-10-21 11:15:20 +00:00
hpayer
726becfb49 Reland Update implementation of atomics with latest Chromium version but use compiler builtin atomics
BUG=

Review-Url: https://chromiumcodereview.appspot.com/2438273002
Cr-Commit-Position: refs/heads/master@{#40496}
2016-10-21 10:05:42 +00:00
jgruber
bac992a114 [regexp] Use consistent map checks for fast paths
These map checks were implemented for TF code already. This CL makes
sure that parts implemented in C++ follow the same logic, which is:

An object is an unmodified regexp if:
1) it's a receiver,
2) its map is the initial regexp map,
3) its prototype is a receiver,
4) and its prototype's map is the initial prototype's initial map.

We can now be smarter in @@replace and @@split since checking maps
(unlike the previous check of RegExp.prototype.exec) is not observable,
so we can perform fast-path checks at a time of our choosing.

BUG=v8:5339,v8:5434,v8:5123

Review-Url: https://chromiumcodereview.appspot.com/2434983002
Cr-Commit-Position: refs/heads/master@{#40495}
2016-10-21 09:58:38 +00:00
hpayer
a007dfc18e [heap] Move typed slot filtering logic into sweeper.
Additionally, remove all code related to the old-style slots filtering and black area end markers.

BUG=chromium:648568

Review-Url: https://chromiumcodereview.appspot.com/2440683002
Cr-Commit-Position: refs/heads/master@{#40494}
2016-10-21 09:05:00 +00:00
machenbach
53aa05cdff [test] Skip flaky test.
BUG=v8:5553
NOTRY=true
TBR=hablich@chromium.org

Review-Url: https://chromiumcodereview.appspot.com/2440693003
Cr-Commit-Position: refs/heads/master@{#40491}
2016-10-21 08:40:12 +00:00
gdeepti
5afa8ed77a [wasm] GrowMemory should update imported memory objects.
When the instance has imported memory, calling GrowMemory should update the memory object to have a consistent view of the memory. This fixes the failing emscripten test case, added a reduced test that simulates the same behavior.

R=titzer@chromium.org, dschuff@chromium.org

Review-Url: https://chromiumcodereview.appspot.com/2438673006
Cr-Commit-Position: refs/heads/master@{#40490}
2016-10-21 08:38:52 +00:00
machenbach
6e162add3e Revert of Update implementation of atomics with latest Chromium version but use compiler builtin atomics (patchset #10 id:190001 of https://chromiumcodereview.appspot.com/2425963002/ )
Reason for revert:
https://build.chromium.org/p/client.v8.ports/builders/V8%20Android%20Arm64%20-%20builder/builds/4851

Original issue's description:
> Update implementation of atomics with latest Chromium version but use compiler builtin atomics
>
> Ideally, we would use the standard library. However, when we are compiling against an older version of the standard library the atomic implementation may be slow.
>
> BUG=

TBR=mlippautz@chromium.org,ulan@chromium.org,jarin@chromium.org,hpayer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review-Url: https://chromiumcodereview.appspot.com/2438983002
Cr-Commit-Position: refs/heads/master@{#40489}
2016-10-21 08:10:31 +00:00
hpayer
343c4ebdd1 Update implementation of atomics with latest Chromium version but use compiler builtin atomics
Ideally, we would use the standard library. However, when we are compiling against an older version of the standard library the atomic implementation may be slow.

BUG=

Review-Url: https://chromiumcodereview.appspot.com/2425963002
Cr-Commit-Position: refs/heads/master@{#40488}
2016-10-21 07:33:10 +00:00
yangguo
2f135d464c [debugger] basic test infrastructure for new debugger test api.
This introduces:
- a way in d8 to send messages to the inspector and receive responses.
- a new test suite where existing debugger tests should migrate to.

R=jgruber@chromium.org, kozyatinskiy@chromium.org, machenbach@chromium.org
BUG=v8:5530

Review-Url: https://chromiumcodereview.appspot.com/2425973002
Cr-Commit-Position: refs/heads/master@{#40487}
2016-10-21 06:38:05 +00:00
neis
209e57e98d [test] Fix typo in assertInstanceOf in mjsunit.js.
R=adamk@chromium.org, marja@chromium.org
BUG=

Review-Url: https://chromiumcodereview.appspot.com/2436073002
Cr-Commit-Position: refs/heads/master@{#40482}
2016-10-20 17:55:52 +00:00
alph
fa0f953297 [profiler] Update cpu profile tracing format.
Encapsulate nodes and samples into cpuProfile object.

BUG=chromium:406277

Review-Url: https://chromiumcodereview.appspot.com/2425093002
Cr-Commit-Position: refs/heads/master@{#40480}
2016-10-20 17:47:09 +00:00
adamk
35a3ccbfac [ignition] Eliminate hole checks where statically possible for loads and stores
Move hole check logic from full-codegen into scope analysis, and store the
"needs hole check" bit on VariableProxy. This makes it easy to re-use in
any backend: it will be trivial to extend the use of this logic in, e.g.,
full-codegen variable stores.

While changing the signatures of the variable loading/storing methods in
Ignition, I took the liberty of replacing the verb "Visit" with "Build", since these
are not part of AST visiting.

BUG=v8:5460

Review-Url: https://chromiumcodereview.appspot.com/2411873004
Cr-Commit-Position: refs/heads/master@{#40479}
2016-10-20 17:32:08 +00:00
jpp
5331e3b616 [V8][asm.js] Adds support to global const variables.
This CL adds support for:
https://discourse.wicg.io/t/allow-const-global-variables/684

It allows global const variables to be used as if they were numeric
literals. For example:

  const f0 = fround(0);
  ...
  function foo() {
    var v = f0;  // no type annotation.
    ...
    return f0;  // no return type annotation.
  }

BUG= https://bugs.chromium.org/p/v8/issues/detail?id=5540

Review-Url: https://chromiumcodereview.appspot.com/2435823002
Cr-Commit-Position: refs/heads/master@{#40477}
2016-10-20 15:48:41 +00:00
heimbuef
ef690ca387 Constrain the zone segment pool size
Added a size constraint to the configuration to limit the segment pool.
This will likely fix the memory alerts from small android devices.

BUG=chromium:655129

Review-Url: https://chromiumcodereview.appspot.com/2424393002
Cr-Commit-Position: refs/heads/master@{#40476}
2016-10-20 14:48:55 +00:00
ahaas
57b14b0606 [wasm] Track in the interpreter if a NaN could have been produced.
The wasm specification does not fully specify the binary representation
of NaN: the sign bit can be non-deterministic. The wasm-code fuzzer
found a test case where the wasm interpreter and the compiled code
produce a different sign bit for a NaN, and as a consequence they
produce different results.

With this CL the interpreter tracks whether it executed an instruction
which can produce a NaN, which are div and sqrt instructions. The
fuzzer uses this information and compares the result of the interpreter
with the result of the compiled code only if there was no instruction
which could have produced a NaN.

R=titzer@chromium.org

TEST=cctest/test-run-wasm-interpreter/TestMayProduceNaN
BUG=chromium:657481

Review-Url: https://chromiumcodereview.appspot.com/2438603003
Cr-Commit-Position: refs/heads/master@{#40474}
2016-10-20 14:27:45 +00:00
mstarzinger
510b56d3f2 Revert "[compiler] Ship Ignition for all TurboFan code."
Breaks layout tests on Blink builders.

TBR=machenbach@chromium.org

Review-Url: https://chromiumcodereview.appspot.com/2428413004
Cr-Commit-Position: refs/heads/master@{#40471}
2016-10-20 14:09:29 +00:00
mstarzinger
2b11a0b92d [interpreter] Enable tests that no longer fail.
R=mythria@chromium.org
BUG=v8:5038

Review-Url: https://chromiumcodereview.appspot.com/2437023002
Cr-Commit-Position: refs/heads/master@{#40470}
2016-10-20 12:48:08 +00:00
ishell
54194b2d8d [stubs] Cleanup CSA::BitFieldDecode(..) and friends.
This CL also introduces IsSetWord<T>(..) and IsSetWord32<T>(..) operations
to ease checking if the bit field is set or not.

BUG=

Review-Url: https://chromiumcodereview.appspot.com/2436893003
Cr-Commit-Position: refs/heads/master@{#40466}
2016-10-20 12:27:42 +00:00
hablich
555a725810 Revert of [inspector] align console implementation with spec (patchset #2 id:20001 of https://chromiumcodereview.appspot.com/2428473003/ )
Reason for revert:
Breaks roll: https://build.chromium.org/p/tryserver.chromium.android/builders/linux_android_rel_ng/builds/164610

See https://chromiumcodereview.appspot.com/2434733002/ for more context

Original issue's description:
> [inspector] align console implementation with spec
>
> console should be non enumerable.
>
> BUG=chromium:656826
> R=dgozman@chromium.org

TBR=dgozman@chromium.org,kozyatinskiy@chromium.org
NOTRY=true
BUG=chromium:656826

Review-Url: https://chromiumcodereview.appspot.com/2435013002
Cr-Commit-Position: refs/heads/master@{#40464}
2016-10-20 11:57:48 +00:00
titzer
85cb43cbb8 [wasm] Fix canonicalization bug for function signatures in CallIndirect.
R=ahaas@chromium.org
BUG=chromium:654231

Review-Url: https://chromiumcodereview.appspot.com/2439613003
Cr-Commit-Position: refs/heads/master@{#40463}
2016-10-20 11:26:26 +00:00
mstarzinger
20d29ff036 [compiler] Ship Ignition for all TurboFan code.
This enables Ignition unconditionally for all code that is destined for
optimization with TurboFan. This ensures all optimization attempts will
go through the BytecodeGraphBuilder and that the AstGraphBuilder pipe is
dried out in practice.

R=mvstanton@chromium.org

Review-Url: https://chromiumcodereview.appspot.com/2427953002
Cr-Commit-Position: refs/heads/master@{#40462}
2016-10-20 10:57:58 +00:00
littledan
1ebe7eb361 test262 roll
Review-Url: https://chromiumcodereview.appspot.com/2435783002
Cr-Commit-Position: refs/heads/master@{#40460}
2016-10-20 10:29:28 +00:00
jkummerow
818d61ab28 [cleanup] Delete MacroAssembler::CopyBytes, it is dead code
Review-Url: https://chromiumcodereview.appspot.com/2434753003
Cr-Commit-Position: refs/heads/master@{#40459}
2016-10-20 10:15:34 +00:00
ulan
0a82f09110 [heap] Add a guard for restarting the memory reducer after mark-compact.
Currently it is possible to get into a cycle of
mark-compact -> memory reducer -> mark-compact -> memory reducer ...
where the memory reducer does not free memory.

This patch ensures that the memory reducer restarts only if the
committed memory increased by sufficient amount after the last run.

BUG=

Review-Url: https://chromiumcodereview.appspot.com/2433933005
Cr-Commit-Position: refs/heads/master@{#40457}
2016-10-20 09:04:37 +00:00
jochen
9780e970ff Add CodeStubAssembler::FlattenString
R=danno@chromium.org
BUG=

Review-Url: https://chromiumcodereview.appspot.com/2435953002
Cr-Commit-Position: refs/heads/master@{#40456}
2016-10-20 08:48:35 +00:00
machenbach
b659cc1e81 Revert of [profiler] Update cpu profile tracing format. (patchset #2 id:20001 of https://chromiumcodereview.appspot.com/2425093002/ )
Reason for revert:
Breaks
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/10805

See also:
https://github.com/v8/v8/wiki/Blink-layout-tests

Original issue's description:
> [profiler] Update cpu profile tracing format.
>
> Encapsulate nodes and samples into cpuProfile object.
>
> BUG=chromium:406277

TBR=caseq@chromium.org,lpy@chromium.org,yangguo@chromium.org,alph@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:406277

Review-Url: https://chromiumcodereview.appspot.com/2432373004
Cr-Commit-Position: refs/heads/master@{#40452}
2016-10-20 07:40:36 +00:00
gdeepti
e936685b0d [wasm] Remove incorrect assembler check.
BUG=chromium:644670
R=ahaas@chromium.org, titzer@chromium.org

Review-Url: https://chromiumcodereview.appspot.com/2438593003
Cr-Commit-Position: refs/heads/master@{#40451}
2016-10-20 07:39:15 +00:00
aseemgarg
cf9ee0ec6c [wasm] simd scalar lowering F32x4Add and I32x4Add
BUG=v8:4124
TEST:test-run-wasm-simd-lowering
R=titzer@chromium.org,bradnelson@chromium.org,gdeepti@chromium.org

Review-Url: https://chromiumcodereview.appspot.com/2294743003
Cr-Commit-Position: refs/heads/master@{#40448}
2016-10-20 00:20:07 +00:00
alph
71e390faf6 [profiler] Update cpu profile tracing format.
Encapsulate nodes and samples into cpuProfile object.

BUG=chromium:406277

Review-Url: https://chromiumcodereview.appspot.com/2425093002
Cr-Commit-Position: refs/heads/master@{#40447}
2016-10-19 19:16:15 +00:00
ahaas
9902368259 [wasm] Trim graph before scheduling.
The scheduler expects a trimmed graph, so we have to trim the graph
before scheduling.

R=titzer@chromium.org, bmeurer@chromium.org
TEST=cctest/test-run-wasm/RunWasmCompiled_GraphTrimming

Review-Url: https://chromiumcodereview.appspot.com/2428443002
Cr-Commit-Position: refs/heads/master@{#40446}
2016-10-19 16:21:36 +00:00
jochen
f4be20cbda Add tests for CodeStubAssembler::ToString
R=danno@chromium.org

Review-Url: https://chromiumcodereview.appspot.com/2438483002
Cr-Commit-Position: refs/heads/master@{#40437}
2016-10-19 13:37:24 +00:00
titzer
418b239f0b [wasm] Use a Managed<WasmModule> to hold metadata about modules.
This CL refactors the handling of metadata associated with WebAssembly
modules to reduce the duplicate marshalling of data from the C++ world
to the JavaScript world. It does this by wrapping the C++ WasmModule*
object in a Foreign that is rooted from the on-heap WasmCompiledModule
(which is itself just a FixedArray). Upon serialization, the C++ object
is ignored and the original WASM wire bytes are serialized. Upon
deserialization, the C++ object is reconstituted by reparsing the bytes.

This is motivated by increasing complications in implementing the JS
API, in particular WebAssembly.Table, which must perform signature
canonicalization across instances.

Additionally, this CL implements the proper base + offset initialization
behavior for tables.

R=rossberg@chromium.org,bradnelson@chromium.org,mtrofin@chromium.org,yangguo@chromium.org
BUG=v8:5507, chromium:575167, chromium:657316

Review-Url: https://chromiumcodereview.appspot.com/2424623002
Cr-Commit-Position: refs/heads/master@{#40434}
2016-10-19 13:07:22 +00:00