Commit Graph

162 Commits

Author SHA1 Message Date
ager@chromium.org
ea8312ba33 Reapply: Never use classic code generator.
Crankshaft is now the default on all platforms. This is the first
patch on the way to removing the classic code generator from the
system.

This time with no removal of the crankshaft flag. --nocrankshaft is
not at all the same as --always-full-compiler which I had used instead
for testing. That was what caused timeouts on the buildbots because of
repeated attempts to optimize hot functions. It makes sense to keep
the crankshaft flag in case you want to run only with the full
compiler and with no adaptive compilation.

R=vitalyr@chromium.org

Review URL: http://codereview.chromium.org/6759070

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7486 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-04-01 19:46:21 +00:00
sgjesse@chromium.org
8099bf3531 Revert "Never use classic code generator."
This reverts r7469 which might have caused the timeouts on the buildbot.

TBR=ager@chromium.org

BUG=
TEST=

Review URL: http://codereview.chromium.org//6788009

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7481 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-04-01 14:38:30 +00:00
sgjesse@chromium.org
1e8079fcc9 Increase coverage of global loads in optimized code
In the cases where a global property cell cannot be used in the optimized code
use standard load ic to get the property instead of bailing out.

This is re-committing r7212 and r7215 which where reverted in r7239 with the addition of recoring the source position in the hydrogen code for the LoadGlobalCell instruction. To record that position an optional position field has been added to the variable proxy AST node.
Review URL: http://codereview.chromium.org/6758007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7474 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-04-01 11:54:04 +00:00
ager@chromium.org
1528bf7240 Never use classic code generator.
Crankshaft is now the default on all platforms. This is the first
patch on the way to removing the classic code generator from the
system.

R=kmillikin@chromium.org
BUG=
TEST=

Review URL: http://codereview.chromium.org/6771045

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7469 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-04-01 10:52:18 +00:00
ager@chromium.org
9eb3bfadd6 Implement %_IsStringWrapperSafeForDefaultValue in full code generators.
R=sgjesse@chromium.org

Review URL: http://codereview.chromium.org/6689006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7465 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-04-01 08:02:12 +00:00
vitalyr@chromium.org
179aef2b8f VM initialization refactoring.
This patch introduces global once per-process initialization and moves
the OS and CPU setup there. This makes CPU features isolate-independent.

Review URL: http://codereview.chromium.org/6670119

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7462 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-31 16:17:37 +00:00
vitalyr@chromium.org
d89c753152 Only pass isolate parameter to C helper functions that need it.
Review URL: http://codereview.chromium.org/6778018

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7450 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-30 18:05:16 +00:00
ager@chromium.org
94c1058ba9 Cleanup more isolate usage in ia32 files.
Review URL: http://codereview.chromium.org/6696107

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7367 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-25 13:21:30 +00:00
vegorov@chromium.org
b97fc27c93 Check for SSE2 support in FullCodeGenerator::EmitMathPow.
Do not emit call to the MathPowStub when SSE2 is not available because it requires SSE2.

Review URL: http://codereview.chromium.org/6736006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7366 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-25 12:51:32 +00:00
ager@chromium.org
1bdc8031fa Introduce accessors on builtins instance and use them to avoid TLS access when getting builtins.
R=vitalyr@chromium.org

Review URL: http://codereview.chromium.org/6717018

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7327 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-23 13:40:07 +00:00
ager@chromium.org
4f5de28a9b Avoid TLS access for counters.
Get rid of the COUNTERS macro and fetch the counters from a locally
stored isolate instead.

R=karlklose@chromium.org

Review URL: http://codereview.chromium.org/6723014

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7321 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-23 11:13:07 +00:00
ager@chromium.org
b69591bc0f Require an isolate parameter for most external reference creation to
avoid TLS access in connection with external references.

Make the isolate accessible via the assembler.

Only for ia32 at this point. If this looks OK to you I will port it.

R=vitalyr@chromium.org

Review URL: http://codereview.chromium.org/6713074

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7305 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-22 13:20:04 +00:00
fschneider@chromium.org
8066271fd2 Optimize calls to object literal properties that are initialized with a function literal.
This allows fast calls and inlining of functions like:

var o = {f: function() { return "foo"; }}
o.f();


Object literals that contain function literals are initially created a dictionary mode
object and only transformed to fast properties once all properties are computed and
added. This allows us to create constant function properties for functions declared
inside the object literal. Function literals inside object literals are marked for
pretenuring so that they work as contant function properties.

Object literals without functions should just function as before.

Review URL: http://codereview.chromium.org/6240012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7283 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-21 12:25:31 +00:00
vitalyr@chromium.org
7976ca2cbc Merge isolates to bleeding_edge.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7271 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-18 20:35:07 +00:00
vitalyr@chromium.org
76e226f832 Revert r7268: it borked the history.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7269 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-18 19:41:05 +00:00
vitalyr@chromium.org
6ff7fdebd3 Merge isolates to bleeding_edge.
Review URL: http://codereview.chromium.org/6685088

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7268 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-18 18:49:56 +00:00
mmaly@chromium.org
4cbf3478d8 Implement strict mode ThrowTypeError functions for arguments object.
* Reverse order of arguments in-object fields for length and callee.
* Introduce arguments ThrowTypeError functions (caller/callee).
* Create strict mode arguments boilerplate object.
* Strict mode "new arguments object" stub.
* Runtime arguments object allocation.
* Update es5conform test expectations.

Review URL: http://codereview.chromium.org/6698015/

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7252 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-17 20:28:41 +00:00
mmaly@chromium.org
55906eb46e Implement fast path for strict closure creation.
Review URL: http://codereview.chromium.org/6677036/

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7251 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-17 20:28:30 +00:00
mmaly@chromium.org
1d1018aec7 Strict mode ThrowTypeError functions for
- function.caller
- function.arguments

Review URL: http://codereview.chromium.org/6694044/

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7250 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-17 20:28:17 +00:00
ricow@chromium.org
d6caa8872a Revert revisions 7215 and 7212.
This caueses line positions to be off by one in certain cases, causing webkit http/tests/inspector/console-xhr-logging to fail.
Review URL: http://codereview.chromium.org/6667077

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7239 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-17 14:30:48 +00:00
sgjesse@chromium.org
1a6c821b05 Increase coverage of global loads in optimized code
In the cases where a global property cell cannot be used in the optimized code use standard load ic to get the property instead of bailing out.
Review URL: http://codereview.chromium.org/6665026

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7212 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-17 08:16:12 +00:00
mmaly@chromium.org
d12d1c40cc Strict mode renames and formatting cleanup.
BUG=
TEST=

Review URL: http://codereview.chromium.org/6693014

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7180 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-15 18:20:10 +00:00
ager@chromium.org
6428822811 Revert "Strict mode ThrowTypeError functions for"
TBR=mmaly@chromium.org

Review URL: http://codereview.chromium.org/6696018

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7173 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-15 11:01:21 +00:00
erik.corry@gmail.com
941701d0b9 Fix SmiCompare on 64 bit to distinguish between comparisons where
we know that both sides are Smi and those where we don't.  Fix inlined
symbol table probes to cope with strings, undefined and null (indicating
a deleted entry).  Some changes to other architectures that were found
with the new asserts.
Review URL: http://codereview.chromium.org/6682026

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7172 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-15 10:03:57 +00:00
mmaly@chromium.org
80bd958df2 Strict mode ThrowTypeError functions for
- function.caller
- function.arguments

Review URL: http://codereview.chromium.org/6691003/

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7168 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-14 17:46:37 +00:00
kmillikin@chromium.org
d31594feae Refactor construction of switch statements to avoid subgraphs.
Refactor construction of switch statements so it doesn't use class
HSubgraph.

There are also a few improvements.  We do not use an auxiliary list of
comparisons because they're embedded as a linked list in the graph
under construction.  We share a common break block for all breaks from
the same switch.  We do not insert empty blocks unless necessary to
maintain edge-split form.

There is also a bug fix.  The entry to a clause body is a potential
join and must have a join ID set, otherwise deoptimization within the
body can go to an unpredictable place in the unoptimized code.

Review URL: http://codereview.chromium.org/6650021

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7099 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-09 12:06:54 +00:00
mmaly@chromium.org
927f341d3c Strict mode arguments do not share binding with formal parameters.
Move strict mode flag from TemporaryScope to Scope so that it can be accessed from variable binding code.
Arguments do not alias in strict mode (ia32, x64 and arm, codegen and full codegen).
Hydrogen tolerates null arguments_shadow().
In codegen-<arch> arguments object is allocated eagerly to capture values before they get modified.

Review URL: http://codereview.chromium.org/6625048/

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7083 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-07 19:23:46 +00:00
whesse@chromium.org
8ff9165055 Simplify test for typeof x == 'y' on all platforms.
Review URL: http://codereview.chromium.org/6606005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7041 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-03 12:16:21 +00:00
mmaly@chromium.org
1d040083b0 Assignment to read only properties throws in strict mode.
Review URL: http://codereview.chromium.org/6594037/

Revert "Revert "Assignment to read only properties throws in strict mode.""

This reverts commit aefcd82e1d36d458dd071ebf4777340f08aa67b1.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7007 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-02 04:53:43 +00:00
vitalyr@chromium.org
9c05698145 Port eval resolve in call optimization from classic to full codegen.
Review URL: http://codereview.chromium.org/6598066

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6998 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-01 15:34:23 +00:00
fschneider@chromium.org
5a9c4aad23 Make the materialization of smi constants consistent between the two compilers.
This change makes the full code generator always materialize smi constants to match the behavior
 of the environment tracked in the optimizing compiler. The mismatch between environment
and what the non-optimized code causes problems and potentially crashes when doing deoptimization
and OSR.

BUG=67732

Review URL: http://codereview.chromium.org/6592064

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6982 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-01 10:58:43 +00:00
sgjesse@chromium.org
8f78eb7d4c Minor change to FullCodeGenerator::EmitFastAsciiArrayJoin
The counting loop is always run at least once, and checking the loop condition once is sufficient.
Review URL: http://codereview.chromium.org/6592010

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6979 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-01 08:17:13 +00:00
mmaly@chromium.org
749b69853a Revert "Assignment to read only properties throws in strict mode."
This reverts commit 503f2a501e504f330821f247074e731aa649b1f0.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6977 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-01 06:10:41 +00:00
mmaly@chromium.org
98aea3c353 Assignment to read only properties throws in strict mode.
Review URL: http://codereview.chromium.org/6594037/

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6976 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-03-01 01:42:37 +00:00
sgjesse@chromium.org
1e08a785a9 ARM: Align full codegen with IA32 version
Use ToBooleanStub in DoTest instead of runtime call.
Try allocation in generated code in VisitRegExpLiteral.
Use TranscendentalCacheStub for sin, cos and log instead of calling runtime.

Minor "alignment" of the full codegen code across platforms.
Review URL: http://codereview.chromium.org/6597003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6953 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-02-25 13:29:02 +00:00
sgjesse@chromium.org
bd2fb51375 ARM: Port r5445
r5445: Implement for-in cache validity checking in the full codegen on IA-32.
Review URL: http://codereview.chromium.org/6581031

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6930 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-02-24 11:39:27 +00:00
mmaly@chromium.org
3ff7aa0ea9 Fix for bug http://code.google.com/p/v8/issues/detail?id=1176.
Review URL: http://codereview.chromium.org/6469083/

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6904 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-02-22 17:20:25 +00:00
kmillikin@chromium.org
123dbb2f5e Change the baseline compiler to match the Hydrogen graph builder.
The Hydrogen graph translation does not build a branch for unary negation in
an effect context, so the baseline compiler should not do so either.

Review URL: http://codereview.chromium.org/6546050

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6871 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-02-21 16:49:39 +00:00
sgjesse@chromium.org
4ce06204f9 ARM: Add inlined smi binary operations in full code generator
Review URL: http://codereview.chromium.org/6529022

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6806 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-02-16 09:20:16 +00:00
mmaly@chromium.org
9adaeb6a17 Strict mode delete of non-configurable property.
Strict mode flag is passed to runtime DELETE function
and then to JSObject::Delete(Property/Element) as STRICT_DELETION enum.
When deleting non-configurable property/eleemnt, TypeError is thrown.
Adding mozilla test to .gitignore.
Incorporate CR feedback.

Review URL: http://codereview.chromium.org/6515005/

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6782 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-02-14 23:41:47 +00:00
mmaly@chromium.org
3711b87e8c Refactoring codegen for delete.
* keep handling of VariableProxy and Property together
* place clauses in the order of discovery

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6778 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-02-14 17:33:06 +00:00
kmillikin@chromium.org
c73ce4f126 Fix a duplicate AST ID recorded for for/in.
Avoid visiting the subexpressions of a variable that rewrites to a property
when occurring as the 'left-hand side' of for/in.

BUG=v8:1149

Review URL: http://codereview.chromium.org/6475009

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6772 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-02-14 12:51:25 +00:00
mmaly@chromium.org
e0be3072b5 Implement assignment to undefined reference in ES5 Strict Mode.
Strict mode assignment to undefined reference.
Simple assignments (x = <value>) use CODE_TARGET_CONTEXT.
StoreIC stores its own strictness in extra_ic_state.
The strcitness is propagated as further ic stubs are generated.

Details:
* ReferenceError on assignment to non-resolvable reference in strict mode.
* Fix es5conform test expectation file.
* Add es5conform test suite into .gitignore.
* Fix Xcode project.
* Change implemented in virtual frame code generator, as well as full-codegen
  for all architectures.
* Fix debugger test.
* Fix comment for CODE_TARGET_CONTEXT
* Implement remaining StoreIC stubs to be strict mode aware.
* Trace extra_ic_state() for ic code stubs.

Code Review URL: http://codereview.chromium.org/6474026/

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6760 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-02-13 16:19:53 +00:00
mmaly@chromium.org
3f4701df7f Revert r6756. Check failed on V8 arm - debug - crankshaft.
Need to investigate.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6757 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-02-11 23:25:07 +00:00
mmaly@chromium.org
fd6338bdda Implement assignment to undefined reference in ES5 Strict Mode.
Strict mode assignment to undefined reference.
Simple assignments (x = <value>) use CODE_TARGET_CONTEXT.
StoreIC stores its own strictness in extra_ic_state.
The strcitness is propagated as further ic stubs are generated.

Details:
* ReferenceError on assignment to non-resolvable reference in strict mode.
* Fix es5conform test expectation file.
* Add es5conform test suite into .gitignore.
* Fix Xcode project.
* Change implemented in virtual frame code generator, as well as full-codegen
  for all architectures.
* Fix debugger test.
* Fix comment for CODE_TARGET_CONTEXT
* Implement remaining StoreIC stubs to be strict mode aware.
* Trace extra_ic_state() for ic code stubs.

Code Review URL: http://codereview.chromium.org/6474026/

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6756 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-02-11 21:39:59 +00:00
kmillikin@chromium.org
2e08148b06 Fix the semantics of delete on parameters.
Before, an attempt to delete a parameter in a function that used the
arguments object in any way would succeed with true and delete both
the parameter and the corresponding arguments object property.

Now, an attempt to delete such a parameter does not delete and
evaluates to false.

Parameters can be deleted, as before, from functions that use the
arguments object, by deleting the corresponding arguments object
property (this is a spec violation).

BUG=fixes v8:1136

Review URL: http://codereview.chromium.org/6484023

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6745 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-02-11 11:57:11 +00:00
kmillikin@chromium.org
ebebcae4c2 Allow esi to be an allocatable register on IA32.
Make esi available to the register allocator rather than dedicating it
permanently to the context.

The context is still passed in register esi to JavaScript and to the runtime
as part of the calling convention.  Because some stubs might end up calling
JS or the runtime, it is also conservatively passed to stubs.

Roughly half the calls have been modified to use the context as an input
value in fixed register esi.  The other half are marked as calls or deferred
code so esi is spilled and can be explicitly set.

It is no longer necessary to restore the context to esi after a call that
might change it.

Review URL: http://codereview.chromium.org/6452001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6713 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-02-10 09:00:50 +00:00
sgjesse@chromium.org
dabc590527 ARM: Add type-feedback recording for compare
Change the comparison in the full code generator to use CompareIC instead of the CompareStub to record the types. This also implements the patching in the full code generator where the inlined smi code is de-activated by default to call the CompareIC once and then activating the inlined smi code by patching the code.

Fixed the smi comparison in the ICCompareStub.

Fixed ToBooleanStub to ensure that the scratch register used is not the input. Use r9 as default as that will never be input with Crankshaft.

Implemented lithium instruction CmpTAndBranch.

Make sure that the lithium instruction CmpID have operands in registrers as the current optimized code expects that.
Review URL: http://codereview.chromium.org/6461017

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6704 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-02-09 14:57:24 +00:00
whesse@chromium.org
602d5cf427 Fix a bug that occurs when functions are defined with more than 16,382 parameters.
Review URL: http://codereview.chromium.org/6447007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6697 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-02-09 12:46:22 +00:00
kmillikin@chromium.org
bf3c3eb9cb Fix a possible duplicate AST ID for deoptimization.
For redeclarations of variables that alias the parameters in functions
using arguments, we need to avoid re-visiting the shared variable
rewrite.

BUG=v8:1104

Review URL: http://codereview.chromium.org/6453004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6679 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-02-08 14:00:22 +00:00