Commit Graph

2595 Commits

Author SHA1 Message Date
ulan@chromium.org
b9e0b87a5a Clear optimized code cache in shared function info when code gets deoptimized.
This adds a pointer to the shared function info into deoptimization data of an optimized code. Whenever the code is deoptimized, it clears the cache in the shared function info.

This fixes the problem when the optimized function dies in new space GC before the code is deoptimized due to code dependency and before the optimized code cache is cleared in old space GC (see mjsunit/regress/regress-343609.js).

This partially reverts r19603 because we need to be able to evict specific code from the optimized code cache.

BUG=343609
LOG=Y
TEST=mjsunit/regress/regress-343609.js
R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/184923002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19635 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-03-03 11:11:39 +00:00
rossberg@chromium.org
5543263c19 Move all Harmony-only tests to harmony/
R=jkummerow@chromium.org
BUG=

Review URL: https://codereview.chromium.org/178583005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19622 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-28 14:26:32 +00:00
ishell@chromium.org
c2601aea8a Check elimination did not mark some dead blocks.
R=danno@chromium.org

Review URL: https://codereview.chromium.org/180483003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19619 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-28 14:16:38 +00:00
svenpanne@chromium.org
e9273332ef Fixed constant folding for Math.clz32.
LOG=y
BUG=347906
R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/184353002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19609 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-28 13:07:10 +00:00
jochen@chromium.org
ba981e58d5 Make a64.release a quickcheck target
I marked all tests as slow that take more than a minute on my machine.
With this, a64.release.quickcheck takes two minutes which is about as
fast as arm.optdebug.quickcheck.

BUG=none
R=ulan@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/183763008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19608 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-28 12:46:13 +00:00
mvstanton@chromium.org
b1ffc7901f A JSArray may have a filler map in the elements pointer.
We already have code that expects this, but incorrectly asserted that the
filler map case would never happen when allocation folding is turned on.
However, even folding has it's limits, bailing out of continued folding
when the object size grows too large. Therefore, it's a general problem
when verifying JSArray objects, that we might encounter a filler map
in elements().

Discovered by ClusterFuzz crbug 347903.

R=hpayer@chromium.org
LOG=N
BUG=347903

Review URL: https://codereview.chromium.org/184493002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19604 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-28 12:29:19 +00:00
yangguo@chromium.org
5c186bb197 Evict from optimized code map in sync with removing from optimized functions list.
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/184443002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19603 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-28 12:27:31 +00:00
bmeurer@chromium.org
70242fe3bb Fix JSObject::PrintTransitions.
BUG=347912
LOG=y
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/183683005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19601 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-28 11:41:07 +00:00
hpayer@chromium.org
38ca2629be Fix representation generalization for doubles.
BUG=
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/184393002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19599 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-28 11:07:10 +00:00
dcarney@chromium.org
98d1cedac4 Get array_function from NativeContext
R=mvstanton@chromium.org
LOG=N
BUG=347528

Review URL: https://codereview.chromium.org/184173003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19595 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-28 10:01:27 +00:00
bmeurer@chromium.org
5945f9ebb9 Fix handling of constant global variable assignments.
BUG=347904
LOG=y
R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/184303003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19594 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-28 09:40:12 +00:00
svenpanne@chromium.org
c4e90c15b8 Removed bogus ASSERT.
LOG=y
BUG=347542
R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/183763007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19592 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-28 08:45:07 +00:00
ishell@chromium.org
2ab83cf192 HAllocate should never generate allocation code if the requested size does not fit into page. Regression test included.
BUG=347543
LOG=N
R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/180803005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19591 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-27 17:33:25 +00:00
rafaelw@chromium.org
d9a66ad941 Runtime::RunMicrotask should silent return if no pending microtask work (rather than asserting)
R=rossberg@chromium.org, rossberg
BUG=347532

Review URL: https://codereview.chromium.org/181013008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19588 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-27 16:49:55 +00:00
verwaest@chromium.org
aa14020bc7 Fix putting of prototype transitions. The length is also subject to GC, just like entry.
BUG=347536
LOG=n
R=danno@chromium.org

Review URL: https://codereview.chromium.org/183193003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19586 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-27 16:07:44 +00:00
jarin@chromium.org
05b98492a4 Handle arguments objects in frame when materializing arguments
R=mstarzinger@chromium.org
BUG=347262

Review URL: https://codereview.chromium.org/177293009

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19584 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-27 15:12:12 +00:00
yangguo@chromium.org
6912a248ca Fix bogus assertion in SetFastDoubleElements.
R=danno@chromium.org
BUG=347530
LOG=N

Review URL: https://codereview.chromium.org/181433016

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19579 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-27 14:45:53 +00:00
mvstanton@chromium.org
b8f8cfabca Fix for Clusterfuzz issue 343928.
The problem was that the debugger didn't expect that a JSFunction could
have a GlobalContext, which it can with harmony scoping.

BUG=343928
R=yangguo@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/183103003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19576 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-27 13:25:05 +00:00
ishell@chromium.org
1ae7e8a1e5 Fix for failing asserts in HBoundsCheck code generation on x64: index register should be zero extended.
BUG=345820
LOG=N
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/180013002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19549 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-25 16:33:54 +00:00
verwaest@chromium.org
d5caecccc5 Revert "Use stability to only conditionally flush information from the CheckMaps table."
R=ishell@chromium.org

Review URL: https://codereview.chromium.org/180023002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19548 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-25 16:11:58 +00:00
jkummerow@chromium.org
e7e93cd433 Mark HCompareMap as having Tagged representation
BUG=chromium:346636
LOG=y
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/176923013

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19545 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-25 15:09:47 +00:00
rossberg@chromium.org
63f1970c6c Fix crasher in Object.getOwnPropertySymbols
R=arv@chromium.org, mstarzinger@chromium.org
BUG=346141
LOG=Y

Review URL: https://codereview.chromium.org/177883002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19539 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-25 12:01:34 +00:00
bmeurer@chromium.org
77f597d387 Don't eliminate loads with incompatible types or representations.
BUG=346343
LOG=y
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/179553002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19536 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-25 09:55:50 +00:00
ishell@chromium.org
6c1659becf Fix for a smi stores optimization on x64 with a regression test.
BUG=345715
LOG=N
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/178833002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19535 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-25 09:55:02 +00:00
dcarney@chromium.org
cb05cff594 negative bounds checking on realm calls
R=rossberg@chromium.org

LOG=N

BUG=344285

Review URL: https://codereview.chromium.org/169393002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19533 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-25 09:15:05 +00:00
jkummerow@chromium.org
37b6fd07c1 Fix optimistic BCE to back off after deopt
BUG=v8:3176
LOG=n
R=danno@chromium.org

Review URL: https://codereview.chromium.org/177523002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19530 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-24 13:15:31 +00:00
verwaest@chromium.org
84b366516e Don't turn objects with empty-string properties into fast-mode.
R=ishell@chromium.org

Review URL: https://codereview.chromium.org/165743003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19511 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-20 16:11:48 +00:00
rossberg@chromium.org
0d34254f8d Upgrade Symbol implementation to match current ES6 behavior.
Refresh the implementation of Symbols to catch up with what the
specification now mandates:

* The global Symbol() function manufactures new Symbol values,
  optionally with a string description attached.

* Invoking Symbol() as a constructor will now throw.

* ToString() over Symbol values still throws, and
  Object.prototype.toString() stringifies like before.

* A Symbol value is wrapped in a Symbol object either implicitly if
  it is the receiver, or explicitly done via Object(symbolValue) or
  (new Object(symbolValue).)

* The Symbol.prototype.toString() method no longer throws on Symbol
  wrapper objects (nor Symbol values.) Ditto for Symbol.prototype.valueOf().

* Symbol.prototype.toString() stringifies as "Symbol("<description>"),
  valueOf() returns the wrapper's Symbol value.

* ToPrimitive() over Symbol wrapper objects now throws.

Overall, this provides a stricter separation between Symbol values and
wrapper objects than before, and the explicit fetching out of the
description (nee name) via the "name" property is no longer supported
(by the spec nor the implementation.)

Adjusted existing Symbol test files to fit current, adding some extra
tests for new/changed behavior.

LOG=N
R=arv@chromium.org, rossberg@chromium.org, arv, rossberg
BUG=v8:3053

Review URL: https://codereview.chromium.org/118553003

Patch from Sigbjorn Finne <sigbjornf@opera.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19490 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-19 14:19:42 +00:00
yangguo@chromium.org
139134acc2 Harmony: optimize Math.clz32.
R=svenpanne@chromium.org
BUG=v8:2938
LOG=N

Review URL: https://codereview.chromium.org/172133003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19487 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-19 13:51:49 +00:00
yangguo@chromium.org
84cf85598d Harmony: implement Math.cbrt, Math.expm1 and Math.log1p.
BUG=v8:2938
LOG=N
R=jarin@chromium.org

Review URL: https://codereview.chromium.org/163563003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19486 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-19 13:49:59 +00:00
ishell@chromium.org
1342cb8b00 Bugfix in check elimination with a regression test.
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/172173003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19481 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-19 12:34:50 +00:00
rossberg@chromium.org
13d99fe778 ES6: Tighten up Object.prototype.__proto__
The spec requires that we throw under certain conditions.

BUG=v8:3064
LOG=y
R=rossberg@chromium.org

Review URL: https://codereview.chromium.org/103853006

Patch from Erik Arvidsson <arv@chromium.org>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19479 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-19 11:59:05 +00:00
jkummerow@chromium.org
6e3b81a7b2 Fix Hydrogen bounds check elimination
When combining bounds checks, they must all be moved before the first load/store
that they are guarding.

BUG=chromium:344186
LOG=y
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/172093002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19475 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-19 10:30:39 +00:00
alexandre.rames@arm.com
62116e2c12 A64: Let the MacroAssembler resolve branches to distant targets.
Code generation would fail when assembling a branch to a label that is bound
outside the immediate range of the instruction. A64 is sensitive to this, as the
various branching instructions have different ranges, going down to +-32KB for
TBZ/TBNZ.  The MacroAssembler is augmented to handle branches to targets that
may exceed the immediate range of instructions.

When branching backward to a label exceeding the instruction range, the
MacroAssembler can simply tweak the generated code to use an unconditional
branch with a longer range. For example instead of
    B(cond, &label);
the MacroAssembler can generate:
    b(InvertCondition(cond), &done);
    b(&label);
    bind(&done);

Since the target is not known when the branch is emitted, forward branches uses
a different mechanism. The MacroAssembler keeps track of forward branches to
unbound labels. When the code generation approaches the end of the range of a
branch, a veneer is generated for the branch.

BUG=v8:3148
LOG=Y
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/169893002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19444 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-18 13:15:32 +00:00
verwaest@chromium.org
60c08a8bf2 Directly store the transition target on LookupResult in TransitionResult.
BUG=chromium:343964
LOG=N
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/170343003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19440 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-18 12:19:32 +00:00
yangguo@chromium.org
be7b023a5c Harmony: implement Math.clz32
R=dslomov@chromium.org, svenpanne@chromium.org
BUG=v8:2938
LOG=N

Review URL: https://codereview.chromium.org/169783002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19435 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-18 10:49:35 +00:00
svenpanne@chromium.org
dbce27047e Fixed and improved code for integral division. Fixed and extended tests.
Arithmetic right shifting is *not* division in two's complement
representation, only in one's complement. So we convert to one's
complement, shift, and go back to two's complement. By permutating the
last steps, one can get efficient branch-free code. This insight comes
from the paleozoic era of computer science, see the paper from 1976:

   Guy Lewis Steele Jr.: "Arithmetic Shifting Considered Harmful"
   ftp://publications.ai.mit.edu/ai-publications/pdf/AIM-378.pdf

This results in better and more correct code than our previous
"neg/shift/neg" dance.

LOG=y
BUG=v8:3151
R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/166793002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19434 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-18 10:45:27 +00:00
yangguo@chromium.org
9ffe004ae4 Harmony: implement Math.fround.
R=jarin@chromium.org
BUG=v8:2938
LOG=N

Review URL: https://codereview.chromium.org/169513002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19433 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-18 10:43:06 +00:00
mvstanton@chromium.org
8bcdbc354f Revert "Add a premonomorphic state to the call target cache."
This reverts commit r19402

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/169713002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19412 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-17 14:22:18 +00:00
mvstanton@chromium.org
be731e6c95 Add a premonomorphic state to the call target cache.
From a CL by kasperl: https://codereview.chromium.org/162903004/

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/163413003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19402 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-17 11:59:45 +00:00
jarin@chromium.org
4c7ed144e1 Comparison in effect context lazy deopt fix.
R=jkummerow@chromium.org
BUG=

Review URL: https://codereview.chromium.org/163623002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19396 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-16 05:51:10 +00:00
ulan@chromium.org
6744ff61ae Fix dictionary element load to pass correct elements kind.
Using FAST_SMI_ELEMENTS triggers optimization on 64-bit architectures that load
only the higher 32 bits of the element. If the element is a pointer to undefined
that has 0 in the higher half than it is erroneously treated as SMI 0.

BUG=v8:3158
LOG=N
TEST=mjsunit/sparse-array-reverse,mjsunit/regress/regress-3158.js
R=danno@chromium.org, ishell@chromium.org

Review URL: https://codereview.chromium.org/166653005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19387 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-14 15:52:24 +00:00
yangguo@chromium.org
68c7523e63 Fix assignment of function name constant.
If it's shadowed by a variable of the same name and both are forcibly
context-allocated, the function is assigned to the wrong context slot.

R=rossberg@chromium.org
BUG=v8:3138
LOG=Y

Review URL: https://codereview.chromium.org/159903008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19379 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-14 12:40:47 +00:00
jarin@chromium.org
8acefb33fe Test and fix for polymorphic named call deoptimization.
The fix removes wrong simulates from the number branch of polymorphic
call/field access handling.

The change also fixes the same thing for polymorphic named field
access even thourgh the field access is probably safe in practice
(because it cannot deoptimize). It is better to keep all our simulates
in sync with full codegen.

R=jkummerow@chromium.org
BUG=

Review URL: https://codereview.chromium.org/166503002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19375 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-14 12:02:39 +00:00
yangguo@chromium.org
a676bc1bbf Fix typed array error message.
R=dslomov@chromium.org
BUG=v8:3159
LOG=N

Review URL: https://codereview.chromium.org/163293002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19369 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-14 09:33:03 +00:00
verwaest@chromium.org
e0960e19aa Fix polymorphic inlining of accessors in a test-context.
R=ishell@chromium.org

Review URL: https://codereview.chromium.org/164003002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19363 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-13 16:55:38 +00:00
m.m.capewell@googlemail.com
028ff21445 A64: Fix some int32 accesses in lithium
This fixes mjsunit/sin-cos. There are further int32 accesses being investigated.

BUG=
R=jochen@chromium.org

Review URL: https://codereview.chromium.org/163553005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19358 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-13 15:49:01 +00:00
ishell@chromium.org
6bb57517c0 Restore of compare-objeq-elim test accidentally removed in r19229.
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/162903005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19354 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-13 12:22:24 +00:00
rafaelw@chromium.org
6b5a4cdef2 V8 Microtask Queue & API
This patch generalizes Object.observe callbacks and promise resolution into a FIFO queue called a "microtask queue".

It also exposes new V8 API which exposes the microtask queue to the embedder. In particular, it allows the embedder to

-schedule a microtask (EnqueueExternalMicrotask)
-run the microtask queue (RunMicrotasks)
-control whether the microtask queue is run automatically within V8 when the last script exits (SetAutorunMicrotasks).

R=dcarney@chromium.org, rossberg@chromium.org, dcarney, rossberg, svenpanne
BUG=

Review URL: https://codereview.chromium.org/154283002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19344 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-12 22:04:19 +00:00
verwaest@chromium.org
161b2f689a Reland: "Use stability to only conditionally flush information from the CheckMaps table."
BUG=
R=ishell@chromium.org

Original CL: https://codereview.chromium.org/153823003

Review URL: https://codereview.chromium.org/153653007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19342 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-12 18:48:12 +00:00