Commit Graph

9296 Commits

Author SHA1 Message Date
domenic
d346834fdc Implement V8 extras utils object
This adds a utils object meant specifically for V8 extras, presenting a limited
API surface for doing things that would otherwise require %-functions.

BUG=v8:4276
LOG=Y
R=jochen@chromium.org,yangguo@chromium.org

Review URL: https://codereview.chromium.org/1343113003

Cr-Commit-Position: refs/heads/master@{#30773}
2015-09-16 21:00:58 +00:00
aperez
d4e1299f16 ES6: Array.prototype.slice and friends should use ToLength instead of ToUint32
Defines a new --harmony-tolength flag, and a ToLengthFlagged() runtime function,
that is used where ES6 requires ToLength(), but a pre-ES6 conversion existed
before. When the flag is disabled, the function uses TO_UINT32(), which is
the pre-ES6 behaviour. When the flag enabled, the ES6-compliant ToLength()
conversion is used.

Based on a patch initially from Diego Pino <dpino@igalia.com>

BUG=v8:3087
LOG=Y

Review URL: https://codereview.chromium.org/1309243003

Cr-Commit-Position: refs/heads/master@{#30772}
2015-09-16 18:01:52 +00:00
fedor
0d017282d3 [objects] do not visit ArrayBuffer's backing store
ArrayBuffer's backing store is a pointer to external heap, and can't be
treated as a heap object. Doing so will result in crashes, when the
backing store is unaligned.

See: https://github.com/nodejs/node/issues/2791

BUG=chromium:530531
R=mlippautz@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/1327403002

Cr-Commit-Position: refs/heads/master@{#30771}
2015-09-16 17:27:59 +00:00
caitpotter88
b444da41ad [es6] support get and set in shorthand properties
Add support for `get` and `set` as shorthand properties. Also
supports them for CoverInitializedName in BindingPatterns and (once implemented)
AssignmentPatterns.

BUG=v8:4412, v8:3584
LOG=N
R=adamk, aperez, wingo, rossberg

Review URL: https://codereview.chromium.org/1328083002

Cr-Commit-Position: refs/heads/master@{#30769}
2015-09-16 16:02:05 +00:00
mvstanton
b5588f48fd Remove --pretenure-call-new
There isn't a plan to turn it on soon, so we'll take it out in favor of cleaner code.

BUG=

Review URL: https://codereview.chromium.org/1202173002

Cr-Commit-Position: refs/heads/master@{#30767}
2015-09-16 15:12:43 +00:00
mstarzinger
2c54dbda35 [turbofan] Make arguments object materialization inlinable.
This makes sure that the arguments object materialization in the method
prologue is composable with respect to inlining. The generic runtime
functions materializing those objects now respect the deoptimization
information when reconstructing the original arguments.

R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/1340313003

Cr-Commit-Position: refs/heads/master@{#30766}
2015-09-16 13:04:34 +00:00
jarin
92903d0a19 [turbofan] Get rid of type lower bounds.
Review URL: https://codereview.chromium.org/1348073002

Cr-Commit-Position: refs/heads/master@{#30764}
2015-09-16 11:55:43 +00:00
mvstanton
905e008c52 Vector ICs: Hook up vectors in platform builtins to their SharedFunctionInfos.
BUG=v8:4423
LOG=N

Review URL: https://codereview.chromium.org/1342013003

Cr-Commit-Position: refs/heads/master@{#30758}
2015-09-16 10:09:00 +00:00
paul.lind
b4f9a95e6c MIPS64: Fix unittests (to not use invalid load representation).
Same as https://codereview.chromium.org/1340303002/

BUG=

Review URL: https://codereview.chromium.org/1339763005

Cr-Commit-Position: refs/heads/master@{#30756}
2015-09-15 21:28:30 +00:00
binji
f5bec4bcd4 [Atomics] Remove support for atomic accesses on floating-point values.
R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1318713007

Cr-Commit-Position: refs/heads/master@{#30755}
2015-09-15 21:25:14 +00:00
adamk
f44efd6b31 Fix spread operator in ArrayLiterals when nested in other literals
Mark ArrayLiterals utilizing the spread operator as non-simple.
This causes them to return false for IsCompileTimeValue, and thus
causes spread to work as expected in nested literals.

BUG=v8:4417
LOG=y

Review URL: https://codereview.chromium.org/1336123002

Cr-Commit-Position: refs/heads/master@{#30754}
2015-09-15 16:43:39 +00:00
jarin
edf6d2adbd [mips] Fix mips unittests (to not use invalid load representation).
Review URL: https://codereview.chromium.org/1340303002

Cr-Commit-Position: refs/heads/master@{#30753}
2015-09-15 15:50:44 +00:00
mlippautz
4d6c4a3e22 Add barriers to atomic utils.
Loads get an acquire, store/cas a release. Increment gets a full barrier.

R=hpayer@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1343883004

Cr-Commit-Position: refs/heads/master@{#30751}
2015-09-15 14:58:54 +00:00
bmeurer
e2f1c26982 [es6] Move builtin constructors for primitives to strict mode.
The ES6 specification says that "Built-in functions that are ECMAScript
function objects must be strict mode functions", which in particular
means that you can never test for them using the "caller" field of a
sloppy mode function.

CQ_INCLUDE_TRYBOTS=tryserver.v8:v8_linux_layout_dbg,v8_linux_nosnap_dbg
R=mstarzinger@chromium.org
BUG=v8:105
LOG=n

Review URL: https://codereview.chromium.org/1347663002

Cr-Commit-Position: refs/heads/master@{#30750}
2015-09-15 14:32:39 +00:00
hpayer
064be4c296 [heap] Move slots buffer into a separate file.
BUG=

Review URL: https://codereview.chromium.org/1343043002

Cr-Commit-Position: refs/heads/master@{#30746}
2015-09-15 12:35:20 +00:00
mstarzinger
9e47ec6eda [turbofan] Fix JSInliner to handle non-returning bodies.
The assumption that every function body produces a value does not hold
for functions that e.g. unconditionally throw or endlessly loop. This
fixes the inlining logic to handle such cases.

R=bmeurer@chromium.org
TEST=mjsunit/regress/regress-crbug-530598
BUG=chromium:530598
LOG=n

Review URL: https://codereview.chromium.org/1333193005

Cr-Commit-Position: refs/heads/master@{#30738}
2015-09-15 11:19:23 +00:00
mstarzinger
887f876058 [turbofan] Model arguments object materialization in graph.
This models the materialization of arguments objects in the prologue
within the IR graph. It will in turn allow us to optimize access to
these objects and also correctly handle them with inlining.

R=bmeurer@chromium.org,mvstanton@chromium.org
TEST=cctest/test-run-jsobjects/Arguments*

Review URL: https://codereview.chromium.org/1344553003

Cr-Commit-Position: refs/heads/master@{#30735}
2015-09-15 09:07:34 +00:00
Ilija.Pavlovic
863ff3e3dd MIPS: Fix testcases r6_beqzc and mov.
Remove incorrect usage of callee-saved FPU regs (f20 and above).
Also remove unnecessary push/pop which were occasionally unpaired,
and caused crash.

TEST=cctest/test-assembler-mips[64]
BUG=

Review URL: https://codereview.chromium.org/1338713004

Cr-Commit-Position: refs/heads/master@{#30729}
2015-09-15 07:37:16 +00:00
jarin
a86db19e0a [turbofan] Limit the load/store machine types to the ones we actually use.
Review URL: https://codereview.chromium.org/1333353005

Cr-Commit-Position: refs/heads/master@{#30725}
2015-09-15 05:45:30 +00:00
rmcilroy
e7fb233946 [Interpreter] Add support for JS calls.
Adds support for JS calls to the interpreter. In order to support
calls from the interpreter, the PushArgsAndCall builtin is added
which pushes a sequence of arguments onto the stack and calls
builtin::Call.

Adds the Call bytecode.

MIPS port contributed by akos.palfi@imgtec.com in https://codereview.chromium.org/1334873002/

BUG=v8:4280
LOG=N

Review URL: https://codereview.chromium.org/1323463005

Cr-Commit-Position: refs/heads/master@{#30710}
2015-09-14 10:05:35 +00:00
cbruni
2f1df49a6c Fixing Sloppy Symbol.iterator setter
In certiain cases the ArgumentsIteratorSetter would trigger an invalid
state in the LookupIterator when being overridden. This is now solved
by bypassing the SetDataProperty and directly using
DefinePropertyOrElementIgnoringAttributes since we know exactly which
property we're going to install

LOG=N
BUG=chromium:521484

Review URL: https://codereview.chromium.org/1332873002

Cr-Commit-Position: refs/heads/master@{#30705}
2015-09-14 07:22:35 +00:00
akos.palfi
a795aa350f MIPS: Save and restore callee-saved FP registers in cctest/ConvertDToI.
Correctly save and restore FP registers in cctest/ConvertDToI to
avoid accidental register overwriting by the generated code.

Note: This failure is manifested only in R6 mode.

TEST=test/cctest/interpreter/test-interpreter
BUG=

Review URL: https://codereview.chromium.org/1337023002

Cr-Commit-Position: refs/heads/master@{#30700}
2015-09-11 15:31:20 +00:00
mlippautz
9fc4fc141f Make FlushICache part of Assembler(Base) and take Isolate as parameter.
BUG=chromium:524425
LOG=N

Review URL: https://codereview.chromium.org/1332283002

Cr-Commit-Position: refs/heads/master@{#30695}
2015-09-11 12:59:47 +00:00
oth
8df7b4f6b5 [Interpreter] Skeleton bytecode graph builder
Add skeleton version bytecode-graph-builder.{h,cc} for existing
bytecodes.

BUG=v8:4280
LOG=N

Review URL: https://codereview.chromium.org/1291693004

Cr-Commit-Position: refs/heads/master@{#30687}
2015-09-10 16:21:40 +00:00
conradw
33ec0b79b8 Parsing especially large nested functions takes up more memory than necessary.
Inner functions must be eagerly parsed for scope analysis, but the full AST is
also kept around even though it's not needed.

This CL mitigates this problem by allocating some AstNodes of the inner function
to a temporary Zone which is deallocated once the scope information has been
built. The remaining nodes (such as VariableProxy) must persist until scope
analysis actually happens, and have to be allocated to a parser-persistent Zone.

BUG=417697
LOG=N

Review URL: https://codereview.chromium.org/1304923004

Cr-Commit-Position: refs/heads/master@{#30685}
2015-09-10 14:41:14 +00:00
caitpotter88
0cc8eaa4c6 [es6] fixup for rest parameters perf test
BUG=v8:2160
LOG=N
NOTRY=true
R=adamk, machenbach@chromium.org, rossberg

Review URL: https://codereview.chromium.org/1331803003

Cr-Commit-Position: refs/heads/master@{#30682}
2015-09-10 13:45:08 +00:00
mythria
edb30522f9 Continuing removing deprecated functions from cctests
Removes deprecated functions from:
- test-unique.cc
- test-unscopables-hidden-prototype.cc
- test-utils-arm64.cc
- test-utils.cc
- test-version.cc
- test-weakmaps.cc
- test-weaksets.cc
- trace-extension.cc
- trace-extension.h

BUG=v8:4134
LOG=n

Review URL: https://codereview.chromium.org/1331013003

Cr-Commit-Position: refs/heads/master@{#30681}
2015-09-10 13:10:01 +00:00
bmeurer
a1b2ec60b0 [runtime] Move binary operator fallbacks into the runtime.
Replace the ADD, SUB, etc. builtins with proper runtime implementations,
and expose them as runtime calls that can be used by the code stubs and
the interpreter (for now).

Also remove all the support runtime functions for ADD, SUB and friends,
namely %NumberAdd, %NumberSub, and so on.

R=mstarzinger@chromium.org
CQ_INCLUDE_TRYBOTS=tryserver.v8:v8_linux_layout_dbg,v8_linux_nosnap_dbg

Review URL: https://codereview.chromium.org/1333843002

Cr-Commit-Position: refs/heads/master@{#30680}
2015-09-10 13:04:33 +00:00
fedor
6da51b4b66 TypedArray accessor detection: consider entire prototype chain
When looking up a special accessor for known TypedArray fields
("length", "byteLength", "byteOffset"), consider the entire prototype
chain, not only the direct prototype.
This allows subclasses of TypedArrays to benefit from fast specialized
accesses.

Review URL: https://codereview.chromium.org/1313493005

Cr-Commit-Position: refs/heads/master@{#30678}
2015-09-10 12:21:55 +00:00
mstarzinger
5e15679809 [turbofan] Disable test that started to timeout.
The two tests in question got a lot slower and started to timeout now
that the C++ fallback implementation of the %Arguments intrinsics is
composable with respect to inlining.

R=bmeurer@chromium.org,machenbach@chromium.org

Review URL: https://codereview.chromium.org/1330203003

Cr-Commit-Position: refs/heads/master@{#30674}
2015-09-10 10:39:17 +00:00
mstarzinger
a676da3ae0 [turbofan] Remove obsolete --turbo-try-catch flag.
This removes the aforementioned flag which has been on by default for a
while now. Note that this does not control optimization decisions, only
the last-resort bailout in the graph builder.

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/1335543002

Cr-Commit-Position: refs/heads/master@{#30673}
2015-09-10 09:38:40 +00:00
bmeurer
6b3c070db6 [runtime] Sanitize %NewClosure runtime entries.
There are now two runtime entries %NewClosure and %NewClosure_Tenured,
with the same signature (one parameter, the SharedFunctionInfo, and the
context of the caller).

Also remove the HFunctionLiteral special case instruction from Crankshaft,
as HCallWithDescriptor with FastNewClosureStub or HCallRuntime with
either %NewClosure or %NewClosure_Tenured can easily do that for you.

Also remove the redundant context parameter from the JSCreateClosure
operator, because every JS operator already takes a context input.

CQ_INCLUDE_TRYBOTS=tryserver.v8:v8_linux_nosnap_dbg

Review URL: https://codereview.chromium.org/1329293003

Cr-Commit-Position: refs/heads/master@{#30671}
2015-09-10 08:36:15 +00:00
mtrofin
96c0e6f96b [turbofan] relative_id of splinters and their children.
A LiveRange is identified by 2 integers: the vreg() of its TopLevel,
which is the virtual register (operand) ID; and a relative_id(), which has
no meaning in the program, but is valuable in debugging or tracing
scenarios.

This change ensures that relative_id is unique even in cases of splinter
ranges and their children.

Review URL: https://codereview.chromium.org/1318493005

Cr-Commit-Position: refs/heads/master@{#30665}
2015-09-09 19:34:11 +00:00
rmcilroy
23f7d34d42 [Interpreter] Add support for property store operations.
Adds support for property store operations via Store/KeyedStore ICs. Adds the
following bytecodes:
 - StoreIC
 - KeyedStoreIC

The --vector_store flag is now required for --ignition.

BUG=v8:4280
LOG=N

Review URL: https://codereview.chromium.org/1319833004

Cr-Commit-Position: refs/heads/master@{#30660}
2015-09-09 15:46:12 +00:00
mvstanton
164f92d206 Crankshaft: consolidated element loads always deopted on seeing the hole
Update the consolidated load case to carefully chose the load mode
based on the consolidated elements kind.

BUG=v8:4380
LOG=N

Review URL: https://codereview.chromium.org/1329793003

Cr-Commit-Position: refs/heads/master@{#30659}
2015-09-09 15:15:30 +00:00
mstarzinger
a504a184f6 [turbofan] Make %Arguments composable with inlining.
This makes the C++ fallback implementations for the two intrinsics,
%Arguments and %ArgumentsLength composable with respect to inlining.
Using deoptimization information gives us accurate data here.

R=bmeurer@chromium.org
TEST=mjsunit/regress/regress-4374
BUG=v8:4374
LOG=n

Review URL: https://codereview.chromium.org/1328363002

Cr-Commit-Position: refs/heads/master@{#30654}
2015-09-09 14:14:18 +00:00
mstarzinger
c505907dce [turbofan] Handle stack overflow exceptions in JSInliner.
R=bmeurer@chromium.org
BUG=chromium:527364
LOG=n

Review URL: https://codereview.chromium.org/1322203005

Cr-Commit-Position: refs/heads/master@{#30651}
2015-09-09 10:24:31 +00:00
caitpotter88
ce95a4db69 [es6] add js-perf-test for rest parameters
BUG=v8:2160
LOG=N
R=adamk, rossberg, wingo

Review URL: https://codereview.chromium.org/1317113007

Cr-Commit-Position: refs/heads/master@{#30647}
2015-09-08 23:17:11 +00:00
dusan.m.milosavljevic
4329a7c2cf MIPS64: [turbofan] Improve changes from and to Smi.
The instruction selection for following sequences is
improved:

  113: Word64Sar(107, 91) : Internal/Any
  114: TruncateInt64ToInt32(113) : Signed32/UntaggedSigned32
  115: ChangeInt32ToFloat64(114) : Signed32/UntaggedFloat64

TEST=unittests/InstructionSelectorTest.ChangesFromToSmi
BUG=

Review URL: https://codereview.chromium.org/1318153006

Cr-Commit-Position: refs/heads/master@{#30645}
2015-09-08 21:55:00 +00:00
ulan
057514d3fa Use idle task to perform incremental marking steps.
This moves incremental marking steps from gc-idle-time-handler and heap to the new incremental marking task.

BUG=chromium:490559
LOG=NO

Review URL: https://codereview.chromium.org/1265423002

Cr-Commit-Position: refs/heads/master@{#30641}
2015-09-08 15:54:37 +00:00
rmcilroy
c9f0368add [Interpreter] Ensure that implicit return undefined is generated.
When there is no explicit return we need to generate an implicit
return undefined.

BUG=v8:4280
LOG=N

Review URL: https://codereview.chromium.org/1308693014

Cr-Commit-Position: refs/heads/master@{#30639}
2015-09-08 15:02:58 +00:00
mstarzinger
819b40aae8 Use baseline code to compute message locations.
This switches Isolate::ComputeLocation to use baseline code when
computing message locations. This unifies locations between optimized
and non-optimized code by always going through the FrameSummary for
location computation.

R=bmeurer@chromium.org
TEST=message/regress/regress-4266
BUG=v8:4266
LOG=n

Review URL: https://codereview.chromium.org/1331603002

Cr-Commit-Position: refs/heads/master@{#30635}
2015-09-08 14:14:59 +00:00
bmeurer
db2ba190db [runtime] Replace many buggy uses of %_CallFunction with %_Call.
The semantics of the %_CallFunction intrinsic seem to be very unclear,
which resulted in a lot of bugs. Especially the combination with
%IsSloppyModeFunction is always a bug, because the receiver would be
wrapped in the wrong context. So the %IsSloppyModeFunction helper is
gone now, and many of the buggy uses of %_CallFunction are also
eliminated.

If you ever need to call something with a different receiver, then
%_Call is your friend now. It does what you want and implements the
call sequence fully (and correct).

BUG=v8:4413
LOG=n

Review URL: https://codereview.chromium.org/1325573004

Cr-Commit-Position: refs/heads/master@{#30634}
2015-09-08 13:35:32 +00:00
jochen
c161799f2c Start removing deprecated APIs from cctest
BUG=4134
R=vogelheim@chromium.org,rmcilroy@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/1333463002

Cr-Commit-Position: refs/heads/master@{#30622}
2015-09-07 14:44:56 +00:00
cbruni
cbdb13533e Adding ElementsAccessor::Concat
- Moving parts of ArrayConcat from builtins.cc to the ElementsAccessor
- Removing ArrayConcat Runtime Function

BUG=v8:4317
LOG=N

Review URL: https://codereview.chromium.org/1330483003

Cr-Commit-Position: refs/heads/master@{#30619}
2015-09-07 13:45:02 +00:00
paul.lind
c772010486 Fix a -Wsign-compare error under GCC 4.9.2.
BUG=

Review URL: https://codereview.chromium.org/1322693004

Cr-Commit-Position: refs/heads/master@{#30603}
2015-09-05 11:43:09 +00:00
bradnelson
12889b4ad2 Follow symlinks in test/mjsunit to allow linked test directories.
Wasm mjsunit tests aren't being detected when symlinked into
test/mjsunit/wasm. This causes symlinked directories in that
directory to be included.

BUG=None
TEST=local
R=dehrenberg@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/1332463002

Cr-Commit-Position: refs/heads/master@{#30600}
2015-09-04 23:16:09 +00:00
karl
24d481165c Reland: Speedup stringsearch for two byte strings
Uses the lower byte with memchr which is
significantly faster than a naive compare

Performance difference with bench (http://hastebin.com/xuxexataso.js):

old                             new

single character                single character
Κ found at 922                  Κ found at 922
3324                            616
㎡ found at 13217               ㎡ found at 13217
42366                           4931
က found at 4096                 က found at 4096
13369                           9836
＀ found at 65280                ＀ found at 65280
207472                          36149
ᆬ found at 65445                ᆬ found at 65445
209344                          36666
  found at 8197                   found at 8197
26731                           11757
倂 found at 20482               倂 found at 20482
66071                           17193

linear search                   linear search
ΚΛ found at 922                 ΚΛ found at 922
4112                            504
㎡㎢ found at 13217             ㎡㎢ found at 13217
55105                           5119
ᆬᆭ found at 65445               ᆬᆭ found at 65445
268016                          35496

linear + bmh search             linear + bmh search
ΚΛΜΝΞΟΠΡ found at 922           ΚΛΜΝΞΟΠΡ found at 922
2897                            522
ᆬᆭᄃᄄᄅᆰᆱᆲ found at 65445         ᆬᆭᄃᄄᄅᆰᆱᆲ found at 65445
167687                          35283

BUG=

Review URL: https://codereview.chromium.org/1324453007

Cr-Commit-Position: refs/heads/master@{#30597}
2015-09-04 19:58:44 +00:00
mlippautz
cd6631ade9 Add template parameter and unittests to atomic utils.
BUG=

Review URL: https://codereview.chromium.org/1324153003

Cr-Commit-Position: refs/heads/master@{#30589}
2015-09-04 14:02:20 +00:00
machenbach
df966cd287 Revert of Speedup stringsearch for two byte strings (patchset #3 id:40001 of https://codereview.chromium.org/1303033012/ )
Reason for revert:
[Sheriff] Breaks fuzzer and msan:
http://build.chromium.org/p/client.v8/builders/V8%20Fuzzer/builds/4773

Repro with:
tools/fuzz-harness.sh out/Debug/d8
(in a ninja Debug build)

Msan:
http://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20arm64%20-%20sim%20-%20MSAN/builds/4097

Original issue's description:
> Speedup stringsearch for two byte strings
>
> Uses the lower byte with memchr which is
> significantly faster than a naive compare
>
> Performance difference with bench (http://hastebin.com/xuxexataso.js):
>
> old                             new
>
> single character                single character
> Κ found at 922                  Κ found at 922
> 3324                            616
> ㎡ found at 13217               ㎡ found at 13217
> 42366                           4931
> က found at 4096                 က found at 4096
> 13369                           9836
> ＀ found at 65280                ＀ found at 65280
> 207472                          36149
> ᆬ found at 65445                ᆬ found at 65445
> 209344                          36666
>   found at 8197                   found at 8197
> 26731                           11757
> 倂 found at 20482               倂 found at 20482
> 66071                           17193
>
> linear search                   linear search
> ΚΛ found at 922                 ΚΛ found at 922
> 4112                            504
> ㎡㎢ found at 13217             ㎡㎢ found at 13217
> 55105                           5119
> ᆬᆭ found at 65445               ᆬᆭ found at 65445
> 268016                          35496
>
> linear + bmh search             linear + bmh search
> ΚΛΜΝΞΟΠΡ found at 922           ΚΛΜΝΞΟΠΡ found at 922
> 2897                            522
> ᆬᆭᄃᄄᄅᆰᆱᆲ found at 65445         ᆬᆭᄃᄄᄅᆰᆱᆲ found at 65445
> 167687                          158465
>
> Committed: https://crrev.com/fced280f37588f8a232a414201276e053117e9ea
> Cr-Commit-Position: refs/heads/master@{#30587}

TBR=danno@chromium.org,mstarzinger@chromium.org,jkummerow@chromium.org,karl@skomski.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1331433002

Cr-Commit-Position: refs/heads/master@{#30588}
2015-09-04 13:00:35 +00:00