Commit Graph

110 Commits

Author SHA1 Message Date
Greg Fischer
00018e58af
Change EliminateDeadInputComponentsPass to EliminateDeadIOComponentsPass (#4997)
To reflect processing of both Input and Output variables.

Also renamed files as needed.
2022-11-25 16:48:13 -07:00
Greg Fischer
c8e1588cfa
Add passes to eliminate dead output stores (#4970)
This adds two passes to accomplish this: one pass to analyze a shader
to determine the input slots that are live. The second pass is run on
the preceding shader to eliminate any stores to output slots that are
not consumed by the following shader.

These passes support vert, tesc, tese, geom, and frag shaders.

These passes are currently only available through the API.

These passes together with dead code elimination, and elimination of
dead input and output components and variables (WIP), will allow users
to do dead code elimination across shader boundaries.
2022-11-02 11:23:25 -06:00
Jaebaek Seo
ad3514b732
spirv-opt: add pass for interface variable scalar replacement (#4779)
Replace shader's stage variables whose types are array or matrix
with scalars/vectors.
For example,
```
Before:
  %foo = OpVariable %_ptr_Output__arr_v2float_uint_4 Output
After:
  %foo = OpVariable %_ptr_Output_v2float Output
  %foo_0 = OpVariable %_ptr_Output_v2float Output
  %foo_1 = OpVariable %_ptr_Output_v2float Output
  %foo_2 = OpVariable %_ptr_Output_v2float Output
```
2022-05-09 14:04:52 -04:00
JiaoluAMD
c11ea09652
spirv-opt : Add FixFuncCallArgumentsPass (#4775)
spirv validation require OpFunctionCall with memory object, usually this
is non issue as all the functions are inlined.
This pass deal with some case for
DontInline function. accesschain input operand would be replaced new
created variable
2022-05-06 10:39:26 -04:00
Greg Fischer
9d1b572884
spirv-opt: (WIP) Eliminate Dead Input Component Pass (#4720)
This adds the --eliminate-dead-input-components pass which currently
removes trailing unused components from input arrays.

Fixes #4532
2022-03-22 20:50:52 -06:00
Steven Perron
920156cf18
Add pass to remove DontInline function control (#4747)
Swift shader needs a way to inline all functions, even those marked as
DontInline.  See https://github.com/KhronosGroup/SPIRV-Tools/pull/4471.
This implements the suggestion I made in the PR.  We add a pass that
will remove the DontInline function control, so that the inlining passes
will inline them.

SwiftShader will still have to modify their code to add this pass before
the other passes are run.
2022-03-07 12:45:17 -05:00
Jaebaek Seo
fb9a10cd48
spirv-opt: add pass to Spread Volatile semantics (#4667)
Add a pass to spread Volatile semantics to variables with SMIDNV,
WarpIDNV, SubgroupSize, SubgroupLocalInvocationId, SubgroupEqMask,
SubgroupGeMask, SubgroupGtMask, SubgroupLeMask, or SubgroupLtMask BuiltIn
decorations or OpLoad for them when the shader model is the ray
generation, closest hit, miss, intersection, or callable shaders. This
pass can be used for VUID-StandaloneSpirv-VulkanMemoryModel-04678 and
VUID-StandaloneSpirv-VulkanMemoryModel-04679 (See "Standalone SPIR-V
Validation" section of Vulkan spec "Appendix A: Vulkan Environment for
SPIR-V").

Handle variables used by multiple entry points:

1. Update error check to make it working regardless of the order of
   entry points.
2. For a variable, if it is used by two entry points E1 and E2 and
   it needs the Volatile semantics for E1 while it does not for E2
  - If VulkanMemoryModel capability is enabled, which means we have to
    set memory operation of load instructions for the variable, we
    update load instructions in E1, but do not update the ones in E2.
  - If VulkanMemoryModel capability is disabled, which means we have
    to add Volatile decoration for the variable, we report an error
    because E1 needs to add Volatile decoration for the variable while
    E2 does not.

For the simplicity of the implementation, we assume that all functions
other than entry point functions are inlined.
2022-01-25 13:14:36 -05:00
Steven Perron
354a46a2a2
Rename strip reflect to strip nonsemantic (#4661)
In https://github.com/KhronosGroup/SPIRV-Tools/pull/3110, the strip reflect
pass was changed to also remove all explicitly nonsemantic instructions.  This
makes it so that the name of the pass no longer reflects what the pass actually
does.  This change renames the pass so that it reflects what the pass actaully does.
2021-12-15 09:55:30 -05:00
Jaebaek Seo
d997c83b10
Add spirv-opt pass to replace descriptor accesses based on variable indices (#4574)
This commit adds a spirv-opt pass to replace accesses to
descriptor array based on variable indices with constant
elements.

Before:
```
%descriptor = OpVariable %_ptr_array_Image Uniform
...
%ac = OpAccessChain %_ptr_Image %descriptor %variable_index
(some image instructions using %ac)
```
After:
```
%descriptor = OpVariable %_ptr_array_Image Uniform
...
OpSwitch %variable_index 0 %case0 1 %case1 ...
...
%case0 = OpLabel
%ac = OpAccessChain %_ptr_Image %descriptor %uint_0
...
%case1 = OpLabel
%ac = OpAccessChain %_ptr_Image %descriptor %uint_1
...
(use OpPhi for value with concrete type)
```
2021-10-26 17:20:58 -04:00
Jaebaek Seo
57e1d8ebe3
Add spirv-opt convert-to-sampled-image pass (#4340)
convert-to-sampled-image pass converts images and/or samplers with
given pairs of descriptor set and binding to sampled image.

If a pair of an image and a sampler have the same pair of descriptor
set and binding that is one of the given pairs, they will be
converted to a sampled image. In addition, if only an image has the
descriptor set and binding that is one of the given pairs, it will
be converted to a sampled image as well.

For example, when we have

  %a = OpLoad %type_2d_image %texture
  %b = OpLoad %type_sampler %sampler
  %combined = OpSampledImage %type_sampled_image %a %b
  %value = OpImageSampleExplicitLod %v4float %combined ...

1. If %texture and %sampler have the same descriptor set and binding

  %combine_texture_and_sampler = OpVaraible %ptr_type_sampled_image_Uniform
  ...
  %combined = OpLoad %type_sampled_image %combine_texture_and_sampler
  %value = OpImageSampleExplicitLod %v4float %combined ...

2. If %texture and %sampler have different pairs of descriptor set and binding

  %a = OpLoad %type_sampled_image %texture
  %extracted_image = OpImage %type_2d_image %a
  %b = OpLoad %type_sampler %sampler
  %combined = OpSampledImage %type_sampled_image %extracted_image %b
  %value = OpImageSampleExplicitLod %v4float %combined ...
2021-08-18 08:30:48 -04:00
dong-ja
c4c6f2ba5c
spirv-opt: Add dataflow analysis framework (#4402)
This PR adds a generic dataflow analysis framework to SPIRV-opt, with the intent of being used in SPIRV-lint. This may also be useful for SPIRV-opt, as existing ad-hoc analyses can be rewritten to use a common framework, but this is not the target of this PR.
2021-08-09 16:43:36 -04:00
dong-ja
7dadcf9c76
Add control dependence analysis to opt (#4380)
Control dependence analysis constructs a control dependence graph,
representing the conditions for a block's execution relative to the
results of other blocks with conditional branches, etc.
This is an analysis pass that will be useful for the linter and
potentially also useful in opt. Currently it is unused except for the
added unit tests.
2021-07-28 12:44:32 -04:00
ZHOU He
f9893c4549
spirv-opt: A pass to removed unused input on OpEntryPoint instructions. (#4275)
The new pass will removed interface variable on the OpEntryPoint instruction when they are not statically referenced in the call tree of the entry point.

It can be enabled on the command line using the options `remove-unused-interface-variables`.
2021-06-29 11:33:58 -04:00
Greg Fischer
48007a5c7f
Add interpolate legalization pass (#4220)
This pass converts an internal form of GLSLstd450 Interpolate ops
to the externally valid form. The external form takes the lvalue
of the interpolant. The internal form can do a load of the interpolant.
The pass replaces the load with its pointer. The internal form is
generated by glslang and possibly other frontends for HLSL shaders.
The new pass is called as part of HLSL legalization after all
propagation is complete.

Also adds internal interpolate form to pre-legalization validation
2021-03-31 14:26:36 -04:00
Ryan Harrison
9150cd441f
Remove WebGPU support (#4108)
Leaves SPV_ENV_WEBGPU_0 enum in place, but marked deprecated, so users
of the library are not broken by an API enum being removed.

Fixes #4101
2021-01-14 16:45:18 -05:00
Jaebaek Seo
56d0f50357
Propagate OpLine to all applied instructions in spirv-opt (#3951)
Based on the OpLine spec, an OpLine instruction must be applied to
the instructions physically following it up to the first occurrence
of the next end of block, the next OpLine instruction, or the next
OpNoLine instruction.

```
OpLine %file 0 0
OpNoLine
OpLine %file 1 1
OpStore %foo %int_1
%value = OpLoad %int %foo
OpLine %file 2 2
```

For the above code, the current spirv-opt keeps three line
instructions `OpLine %file 0 0`, `OpNoLine`, and `OpLine %file 1 1`
in `std::vector<Instruction> dbg_line_insts_` of Instruction class
for `OpStore %foo %int_1`. It does not put any line instruction to
`std::vector<Instruction> dbg_line_insts_` of
`%value = OpLoad %int %foo` even though `OpLine %file 1 1` must be
applied to `%value = OpLoad %int %foo` based on the spec.

This results in the missing line information for
`%value = OpLoad %int %foo` while each spirv-opt pass optimizes the
code. We have to put `OpLine %file 1 1` to
`std::vector<Instruction> dbg_line_insts_` of
both `%value = OpLoad %int %foo` and `OpStore %foo %int_1`.

This commit conducts the line instruction propagation and skips
emitting the eliminated line instructions at the end, which are the same
with PropagateLineInfoPass and RedundantLineInfoElimPass. This
commit removes PropagateLineInfoPass and RedundantLineInfoElimPass.

KhronosGroup/glslang#2440 is a related PR that stop using
PropagateLineInfoPass and RedundantLineInfoElimPass from glslang.
When the code in this PR applied, the glslang tests will pass.
2020-10-29 13:06:30 -04:00
Jaebaek Seo
42268740c9
Add debug information analysis (#3305)
We need an analysis for OpenCL.DebugInfo.100 extension instructions such
as a map between function id and its DebugFunction. This commit add an
analysis for it.
2020-04-27 15:18:55 -04:00
greg-lunarg
1fe9bcc108
Instrument: Debug Printf support (#3215)
Create a pass to instrument OpDebugPrintf instructions.  This pass replaces all OpDebugPrintf instructions with instructions to write a record containing the string id and the all specified values into a special printf output buffer (if space allows). This pass is designed to support the printf validation in the Vulkan validation layers.

Fixes #3210
2020-03-12 09:19:52 -04:00
greg-lunarg
d11725b1d4 Add --relax-float-ops and --convert-relaxed-to-half (#2808)
The first pass applies the RelaxedPrecision decoration to all executable
instructions with float32 based type results. The second pass converts
all executable instructions with RelaxedPrecision result to the equivalent
float16 type, inserting converts where necessary.
2019-09-03 13:22:13 -04:00
Steven Perron
35d98be3bc
Amd ext to khr (#2811)
Add the first steps to removing the AMD extension VK_AMD_shader_ballot.
Splitting up to make the PRs smaller.

Adding utilities to add capabilities and change the version of the
module.

Replaces the instructions:

OpGroupIAddNonUniformAMD = 5000
OpGroupFAddNonUniformAMD = 5001
OpGroupFMinNonUniformAMD = 5002
OpGroupUMinNonUniformAMD = 5003
OpGroupSMinNonUniformAMD = 5004
OpGroupFMaxNonUniformAMD = 5005
OpGroupUMaxNonUniformAMD = 5006
OpGroupSMaxNonUniformAMD = 5007

and extentend instructions

WriteInvocationAMD = 3
MbcntAMD = 4

Part of #2814
2019-08-29 12:48:17 -04:00
greg-lunarg
06407250a1 Instrument: Add support for Buffer Device Address extension (#2792) 2019-08-16 09:18:34 -04:00
Steven Perron
60043edfa1
Replace OpKill With function call. (#2790)
We are no able to inline OpKill instructions into a continue construct.
See #2433.  However, we have to be able to inline to correctly do
legalization.  This commit creates a pass that will wrap OpKill
instructions into a function of its own.  That way we are able to inline
the rest of the code.

The follow up to this will be to not inline any function that contains
an OpKill.

Fixes #2726
2019-08-14 09:27:12 -04:00
Steven Perron
4b64beb1ae
Add descriptor array scalar replacement (#2742)
Creates a pass that will replace a descriptor array with individual variables.  See #2740 for details.

Fixes #2740.
2019-08-08 10:53:19 -04:00
David Neto
31590104ec
Add pass to inject code for robust-buffer-access semantics (#2771)
spirv-opt: Add --graphics-robust-access

Clamps access chain indices so they are always
in bounds.

Assumes:
- Logical addressing mode
- No runtime-array-descriptor-indexing
- No variable pointers

Adds stub code for clamping coordinate and samples
for OpImageTexelPointer.

Adds SinglePassRunAndFail optimizer test fixture.

Android.mk: add source/opt/graphics_robust_access_pass.cpp

Adds Constant::GetSignExtendedValue, Constant::GetZeroExtendedValue
2019-07-30 19:52:46 -04:00
greg-lunarg
92c41ff1e7 Remove Common Uniform Elimination Pass (#2731)
Remove Common Uniform Elimination Pass

Fixes #2520.
2019-07-12 11:02:10 -04:00
Ryan Harrison
f6d9a17843
Add pass to fix some invalid unreachable blocks for WebGPU (#2563)
Attempts to split up unreachable blocks that are used both as a
merge-block and a continue-target.

Fixes #2429
2019-05-09 12:56:10 -04:00
Steven Perron
32af42616a
Change implementation of post order CFG traversal (#2543)
* Change implementation of post order CFG traversal

It seems like the recursion is going very deep, and causing some problem
is particular situations.  I've reimplemented the CFG post order
traversal to not use recursion.

Fixes #2539.
2019-04-29 17:09:20 -04:00
Ryan Harrison
048dcd38ce
Implement WebGPU->Vulkan initializer conversion for 'Function' variables (#2513)
WebGPU requires certain variables to be initialized, whereas there are
known issues with using initializers in Vulkan. This PR is the first
of three implementing a pass to decompose initialized variables into
a variable declaration followed by a store. This has been broken up
into multiple PRs, because there 3 distinct cases that need to be
handled, which require separate implementations.

This first PR implements the basic infrastructure that is needed, and
handling of Function storage class variables. Private and Output will
be handled in future PRs.

This is part of resolving #2388
2019-04-16 14:31:36 -04:00
Ryan Harrison
102e430a88
Add pass to legalize OpVectorShuffle for WebGPU (#2509)
In WebGPU, the component operand 0xFFFFFFFF is forbidden, but in
Vulkan it is used to indicate a value is undefined. When converting to
WebGPU, 0xFFFFFFFF needs to converted to a legal value, though the
specific one does not matter, since it was used to indicate an
undefined entry in the original code. Choosing to use 0, since the
operands are required to be on [0, N-1], so 0 is guaranteed to always
be valid.

Fixes #2349
2019-04-12 12:14:23 -04:00
Steven Perron
3a0bc9e724
Add fix storage class code. (#2434)
This pass tries to fix validation error due to a mismatch of storage classes
in instructions.  There is no guarantee that all such error will be fixed,
and it is possible that in fixing these errors, it could lead to other
errors.

Fixes #2430.
2019-04-05 13:12:08 -04:00
Ryan Harrison
01964e325f
Add pass to generate needed initializers for WebGPU (#2481)
Fixes #2387
2019-04-03 11:44:09 -04:00
Ryan Harrison
e545522146
Add --strip-atomic-counter-memory (#2413)
Adds an optimization pass to remove usages of AtomicCounterMemory
bit. This bit is ignored in Vulkan environments and outright forbidden
in WebGPU ones.

Fixes #2242
2019-03-14 13:34:33 -04:00
Steven Perron
1b0047f210
Add pass to remove dead members. (#2379)
Add a pass that looks for members of structs whose values do not affects
the output of the shader. Those members are then removed and just
treated like padding in the struct.
2019-02-14 13:42:35 -05:00
Steven Perron
dd4157dcee
Sink (#2284)
Add code sinking pass. It will move OpLoad and OpAccessChain instructions as close as possible to their uses.

Part of #1611.
2019-01-17 15:56:36 -05:00
alan-baker
06c9dc07bd
Upgrade modf and frexp (#2266)
Fixes #2138

* Modf and frexp are upgraded to use the struct version of the
instruction and generate an explicit store whose flags can be upgraded
separately
* Fixed major bug where availability and visibility were reversed for
non-copy memory instructions
* Fixed bug where availability and visibility scope operands were reversed for copy memory
* Upgraded all opt tests to use SPV_ENV_UNIVERSAL_1_3
* Upgrade tests moved into unified tests and removed standalone test
2019-01-07 12:36:38 -05:00
Jeff Bolz
8fc8dfe4a5 Add PCH_FILE for upgrade_memory_model target. MSVC doesn't like building pass_utils.cpp twice in the same folder with different PCH settings. (#2186) 2018-12-10 10:54:19 -05:00
alan-baker
e510b1bac5
Update memory model (#1904)
Upgrade to VulkanKHR memory model

* Converts Logical GLSL450 memory model to Logical VulkanKHR
* Adds extension and capability
* Removes deprecated decorations and replaces them with appropriate
flags on downstream instructions
* Support for Workgroup upgrades
* Support for copy memory
* Adding support for image functions
* Adding barrier upgrades and tests
* Use QueueFamilyKHR scope instead of device
2018-11-30 14:15:51 -05:00
Steven Perron
2d2a512691
Don't inline recursive functions. (#2130)
* Move ProcessFunction* function from pass to the context.

There are a few functions that are used to traverse the call tree.
They currently live in the Pass class, but they have nothing to do with
a pass, and may be needed outside of a pass.  They would be better in
the ir context, or in a specific call tree class if we ever have a need
for it.

* Don't inline recursive functions.

Inlining does not check if a function is recursive or not.  This has
been fine as long as the shader was a Vulkan shader, which forbid
recursive functions.  However, not all shaders are vulkan, so either
we limit inlining to Vulkan shaders or we teach it to look for recursive
functions.

I prefer to keep the passes as general as is reasonable.  The change
does not require much new code in inlining and gives a reason to refactor
some other code.

The changes are to add a member function to the Function class that
checks if that function is recursive or not.

Then this is used in inlining to not inlining a function call if it calls
a recursive function.

* Add id to function analysis

There are a few places that build a map from ids to Function whose
result is that id.  I decided to add an analysis to the context for this
to reduce that code, and simplify some of the functions.

* Add missing file.
2018-11-29 14:24:58 -05:00
greg-lunarg
c37388f1ad Add passes to propagate and eliminate redundant line instructions (#2027). (#2039)
These are bookend passes designed to help preserve line information
across passes which delete, move and clone instructions. The propagation
pass attaches a debug line instruction to every instruction based on
SPIR-V line propagation rules. It should be performed before optimization.
The redundant line elimination pass eliminates all line instructions
which match the previous line instruction. This pass should be performed
at the end of optimization to reduce physical SPIR-V file size.

Fixes #2027.
2018-11-15 14:06:17 -05:00
greg-lunarg
1e9fc1aac1 Add base and core bindless validation instrumentation classes (#2014)
* Add base and core bindless validation instrumentation classes

* Fix formatting.

* Few more formatting fixes

* Fix build failure

* More build fixes

* Need to call non-const functions in order.

Specifically, these are functions which call TakeNextId(). These need to
be called in a specific order to guarantee that tests which do exact
compares will work across all platforms. c++ pretty much does not
guarantee order of evaluation of operands, so any such functions need to
be called separately in individual statements to guarantee order.

* More ordering.

* And more ordering.

* And more formatting.

* Attempt to fix NDK build

* Another attempt to address NDK build problem.

* One more attempt at NDK build failure

* Add instrument.hpp to BUILD.gn

* Some name improvement in instrument.hpp

* Change all types in instrument.hpp to int.

* Improve documentation in instrument.hpp

* Format fixes

* Comment clean up in instrument.hpp

* imageInst -> image_inst

* Fix GetLabel() issue.
2018-11-08 13:54:54 -05:00
Jeff Bolz
c06a35b902 Rename PCH macro to spvtools_pch to avoid conflicts with other projects. Also add pch to test/opt. (#2034) 2018-11-07 09:15:04 -05:00
dan sinclair
9e6f5134d1
Reduce number of test targets (#2024)
This CL takes the various opt unit tests and makes a single executable
instead of one per test. This reduces the number of build targets by
~125 when building with ninja.
2018-11-01 10:19:37 -04:00
Steven Perron
5f599e700e
Fix infinite loop in dead-branch-elimination (#1891)
* Create structed cfg analysis.

There are lots of optimization that have to traverse the CFG in a
structured order just because it wants to know which constructs a
basic block in contained in.  This adds extra complexity to these
optimizations, for causes too much refactoring of older optimizations.

To help with this problem, I have written an analysis that can give this
information.

* Identify branches breaking from loops.

Dead branch elimination does a search for a conditional branch to the
end of the current selection construct.  This search assumes that the
only way to leave the construct is through the merge node.  But that is
not true.  The code can jump to the merge node of a loop that contains
the construct.

The search needs to take this into consideration.
2018-09-17 13:00:24 -04:00
Alan Baker
755e5c9420 Transform to combine consecutive access chains
* Combines OpAccessChain, OpInBoundsAccessChain, OpPtrAccessChain and
OpInBoundsPtrAccessChain
* New folding rule to fold add with 0 for integers
 * Converts to a bitcast if the result type does not match the operand
 type
V
2018-07-31 13:42:47 -04:00
Steven Perron
9ecbcf5fc8 Make sure the constant folder get the correct type.
There are a few locations where we need to handle duplicate types.  We
cannot merge them because they may be needed for reflection.  When this
happens we need do some extra lookups in the type manager.

The specific fixes are:

1) When generating a constant through `GetDefiningInstruction` accept
and use an id for the desired type of the constant.  This will make sure
you get the type that is needed.

2) In Private-to-local, make sure we to update the def-use chains when a
new pointer type is created.

3) In the type manager, make sure that `FindPointerToType` returns a
pointer that points to the given type and not a duplicate type.

4) In scalar replacment, make sure the null constants that are created
are the correct type.
2018-07-05 14:34:30 -04:00
Steven Perron
af430ec822 Add pass to fold a load feeding an extract.
We have already disabled common uniform elimination because it created
sequences of loads an entire uniform object, then we extract just a
single element.  This caused problems in some drivers, and is just
generally slow because it loads more memory than needed.

However, there are other way to get into this situation, so I've added
a pass that looks specifically for this pattern and removes it when only
a portion of the load is used.

Fixes #1547.
2018-05-14 15:40:34 -04:00
Steven Perron
2c0ce87210
Vector DCE (#1512)
Introduce a pass that does a DCE type analysis for vector elements
instead of the whole vector as a single element.

It will then rewrite instructions that are not used with something else.
For example, an instruction whose value are not used, even though it is
referenced, is replaced with an OpUndef.
2018-04-23 11:13:07 -04:00
Victor Lomuller
0ec08c28c1 Add register liveness analysis.
For each function, the analysis determine which SSA registers are live
at the beginning of each basic block and which one are killed at
the end of the basic block.

It also includes utilities to simulate the register pressure for loop
fusion and fission.

The implementation is based on the paper "A non-iterative data-flow
algorithm for computing liveness sets in strict ssa programs" from
Boissinot et al.
2018-04-20 09:45:15 -04:00
Alexander Johnston
61b50b3bfa ZIV and SIV loop dependence analysis.
Provides functionality to perform ZIV and SIV dependency analysis tests
between a load and store within the same loop.

Dependency tests rely on scalar analysis to prove and disprove dependencies
with regard to the loop being analysed.

Based on the 1990 paper Practical Dependence Testing by Goff, Kennedy, Tseng

Adds support for marking loops in the loop nest as IRRELEVANT.
Loops are marked IRRELEVANT if the analysed instructions contain
no induction variables for the loops, i.e. the loops induction
variable is not relevent to the dependence of the store and load.
2018-04-11 09:32:42 -04:00
Stephen McGroarty
ad7e4b8401 Initial patch for scalar evolution analysis
This patch adds support for the analysis of scalars in loops. It works
by traversing the defuse chain to build a DAG of scalar operations and
then simplifies the DAG by folding constants and grouping like terms.
It represents induction variables as recurrent expressions with respect
to a given loop and can simplify DAGs containing recurrent expression by
rewritting the entire DAG to be a recurrent expression with respect to
the same loop.
2018-03-28 16:34:23 -04:00