Commit graph

1115 commits

Author SHA1 Message Date
Bill Currie
b0207f4dc9 [qfcc] Allow demotion of implicit literals
This fixes the modulo test.
2024-11-24 18:12:51 +09:00
Bill Currie
1893df34a3 [qfcc] Add an intrinsic expression type
This will be fore generating specific SPIR-V instructions via function
calls, and could be useful for Ruamoko, too.
2024-11-22 23:44:37 +09:00
Bill Currie
0dfe81bce8 [qfcc] Move ruamoko attribute parsing out of the parser
Makes for better separation of variable and function attributes.
2024-11-22 14:15:08 +09:00
Bill Currie
c16a8411bc [qfcc] Extend handles to support image types
Images are just handles, but they have additional type data like
dimensionality, array, etc that distinguishes between the image types.
2024-11-21 19:18:13 +09:00
Bill Currie
03c47f8af7 [qfcc] Support (partially) attributes on types
For now, it's just recording that type type has attributes (encoding
begins with %) and resurrecting types_same which is used only when
matching with types with attributes, so there's still a fair bit of work
to do.
2024-11-21 08:30:47 +09:00
Bill Currie
5e605aee36 [qfcc] Clean up some overzealous const correctness
I'm not sure why I made those functions take const type_t *, but they
didn't need it. There's still a relevant fixime in find_handle, but I
haven't decided how to fix that one just yet.
2024-11-21 08:30:47 +09:00
Bill Currie
943cf9659b [qfcc] Make requiring @overload a language feature
Ruamoko still needs @overload (for now), but now glsl does not.
2024-11-18 22:46:14 +09:00
Bill Currie
3dc22d8cd6 [qfcc] Support spir-v vector expressions even better
It turned out I did need direct vector expression support: the previous
commit handled only assignments, not sub-expressions.
2024-11-18 15:47:22 +09:00
Bill Currie
9b2240aaf8 [qfcc] Implement vector expressions for spir-v
And fix a little goof with VectorShuffle (c&p coding bites again).
2024-11-18 14:55:32 +09:00
Bill Currie
28e8697ae6 [qfcc] Implement compound initializers for spir-v
They don't yet support designators, and vectors aren't treated the way I
want, but my little test works correctly.
2024-11-17 22:45:18 +09:00
Bill Currie
91a93d7803 [qfcc] Add type_count() function
It returns the number of elements in a type (so something like `countof`
(hopefully that's what the up-coming C feature will be called) can be
implemented), but it applies to structs, vectors, etc (eg, 9 for mat3).
2024-11-17 16:12:27 +09:00
Bill Currie
d082d39e17 [qfcc] Use count for number of array elements
I got tired of seeing size when count is the real intent (mistake copied
from C++).
2024-11-17 15:27:10 +09:00
Bill Currie
2115e962fe [qfcc] Support typed compound initializers
Explicitly typed compound initializers are what C uses and allows them
to initialized `auto` vars and even pass through `...`. Not tested yet
other than ensuring existing tests didn't break.
2024-11-17 13:17:36 +09:00
Bill Currie
a7f9d96a02 [qfcc] Implement select (if) constructs
And break/continue too, since my test for them required select.
2024-11-16 23:13:46 +09:00
Bill Currie
93d116cf16 [qfcc] Rename body_first to do_while
Since loops are always while or do-while (for loops are just while loops
with an init block), it made more sense in the end.
2024-11-16 23:10:54 +09:00
Bill Currie
3797b1083b [qfcc] Implement loops for spir-v
Mostly, at least: continue and break aren't functional yet, and for
loops haven't been tested, but while and do-while seem to work.
2024-11-16 19:29:41 +09:00
Bill Currie
89dac4a1b8 [qfcc] Create scopes for while and for loops in glsl
I guess that was a mental FIXME for later, but later came sooner. The
declaration doesn't seem to be working properly, but I'll worry about
that later when I can get some automated tests going.
2024-11-16 19:29:41 +09:00
Bill Currie
22794caf11 [qfcc] Support vector value expressions for spir-v
It seems constant initializers are different from constants in an
expression.
2024-11-16 18:54:31 +09:00
Bill Currie
ebb3ec592a [qfcc] Implement bool and lbool types
Since spir-v needs actual bools for its conditional instructions, the
time to do bool properly finally came. As expected, the changes caused
quite a mess, but Ruamoko now does bool/true/false.
2024-11-15 12:36:08 +09:00
Bill Currie
81cc736683 [qfcc] Add is_signed and is_unsigned type check functions
Makes implementing casts for spir-v much easier.
2024-11-15 10:49:07 +09:00
Bill Currie
d6d44b62d9 [qfcc] Use bool for type is_* functions
More clarity often helps.
2024-11-15 10:49:07 +09:00
Bill Currie
dc85a4df4b [qfcc] Specify entry-point interface variables
Yet another step closer to having a working glsl compiler.
2024-11-14 20:58:21 +09:00
Bill Currie
c5613ba1e4 [qfcc] Use tagged references for spir-v storage
The tags might have other uses thus the generic term, but this allows
spir-v variables to be declared with the correct pointer storage
classes. Now spirv-val is complaining about my interfaces, so progress :)
2024-11-14 18:37:38 +09:00
Bill Currie
698430630d [qfcc] Emit spir-v global variables
This required adding a `var` symbol type. For now, it holds just the
storage class, but it might be good for the initializer, too.

Also, clean up some pointer/reference inconsistencies.
2024-11-14 09:04:48 +09:00
Bill Currie
549203d05d [qfcc] Correct a comment 2024-11-13 13:36:46 +09:00
Bill Currie
e4e04b183a [qfcc] Switch is_lvalue to use bool instead of int
Self documentation for the win.
2024-11-13 12:13:05 +09:00
Bill Currie
32bf9e9435 [qfcc] Generate spir-v function calls
The function parameter and argument types are a mess with respect to
references (and thus calls don't pass validation) but the generated code
seems to be otherwise correct.
2024-11-12 18:24:40 +09:00
Bill Currie
f9345caeb3 [qfcc] Clean up spirv instruction generation
This should make it easier to declare local variables on the fly (needed
for function arguments).
2024-11-12 01:26:20 +09:00
Bill Currie
bcfd1b7660 [qfcc] Split out the call related expression code
I've long felt build_function_call was getting a bit big, and expr.c
especially so. This should make it easier to rewrite build_function_call
for dealing with target-specific code. As a bonus, the int through ...
warning is already cleaned up.
2024-11-04 20:28:30 +09:00
Bill Currie
a0845e65fb [qfcc] Use temp expressions as spir-v id carriers
spir-v uses SSA, so temps cannot be assigned to directly, so instead use
the temp expression as a reference for the result id of the rhs of the
assignment. This would get function calls working if the they actually
emitted any code (right now, just a place-holder id so spirv-dis doesn't
fall over).
2024-11-04 16:42:44 +09:00
Bill Currie
95cedd879a [qfcc] Remove a stale macro
I don't remember what it was for even, other than somehow dereferencing
a pointer def.
2024-11-04 16:38:51 +09:00
Bill Currie
6358143795 [qfcc] Clean up the local_expr global
I never liked it and it made things a little difficult for spir-v.
2024-11-04 16:38:07 +09:00
Bill Currie
5bf9d3c57c [qfcc] Implement spir-v assignment to vars
Since actual variables are always references, they need to written via
OpStore.
2024-11-04 12:53:21 +09:00
Bill Currie
9da3ac3fdc [qfcc] Clean up some int/bool/nullptr cruft 2024-11-04 12:29:30 +09:00
Bill Currie
9d7680228c [qfcc] Attempt to generate code for functions
It sorta kinda works, but there's a lot of bugs, and a lot more stuff to
implement, and the result doesn't pass validation yet.
2024-11-03 23:45:54 +09:00
Bill Currie
04560f61a6 [qfcc] Separate out backend variable declaration
This time, rua/v6p/v6 share the code properly, since it's only spirv
that needs something specific at this stage.
2024-11-03 18:06:25 +09:00
Bill Currie
88c67b3575 [doc] Update doxygen config via doxygen
Also, fix some missing docs. Unfortunately, there are still some
problems (incorrect resolution for multiple files/functions with the
same name, and a bug with doxygen's verbatim/code blocks).
2024-11-03 16:58:10 +09:00
Bill Currie
c8fbb93424 [qfcc] Separate out backend function building
It turns out that emit_function should have been (something like)
build_code and had the stack/locals related code taken along with it.
2024-11-03 16:58:10 +09:00
Bill Currie
a22d2a9526 [qfcc] Move guts of emit_function to per-target code
Ruamoko and v6(p) have their own copies despite being (currently) the
same, and spir-v's is currently empty, but now targeting spir-v doesn't
try to emit ruamoko code.
2024-10-26 23:30:37 +09:00
Bill Currie
95eaa4c65e [qfcc] Implement 64-bit bool
I'm not certain it's what I want, but this fixes the double.r test which
began failing with the non-scalar unary ops change.
2024-10-26 22:16:02 +09:00
Bill Currie
af42b8e221 [qfcc] Support references in expressions
While a reference var can't be initialized yet, using them seems to work
in that they get dereferenced when the value needs to be read or written
(though I haven't seen any generated code for them yet).
2024-10-26 13:33:18 +09:00
Bill Currie
6db1942bb1 [qfcc] Make max_params a code option
Rather than relying on progsversion (I think this also fixes a bug with
max params when targeting ruamoko).
2024-10-11 10:01:45 +09:00
Bill Currie
a61e20ab20 [qfcc] Add parameters to spir-v function scopes
Simple functions now get to the code-gen phase (where they fail since
it's the wrong for other reasons). Parameter types aren't right for
spir-v yet as non-const params need to be references.
2024-10-08 11:58:24 +09:00
Bill Currie
c3f11ba754 [qfcc] Add basic (type) support for references
I realized that spir-v pointers are essentially references (the way
they're used) since OpVariable requires a pointer type rather than the
base type. Thus, under the hood, references are just pointers with
automatic dereferencing. However, nothing uses references yet, and I
expect to run into issues with is_pointer vs is_reference vs is_ptr
(high-level pointer, reference, low-level pointer, respectively).
2024-10-08 11:45:51 +09:00
Bill Currie
dae442c91e [qfcc] Move function scope building into target
This nicely separates Ruamoko and V6p function scope creation, and then
makes spir-v's a no-op (for now).
2024-10-07 09:48:44 +09:00
Bill Currie
0cf8e7cb41 [qfcc] Start properly separating target code
I'd gotten tired of all the convoluted progs version checks, and with
the addition of spirv, they're not even always relevant, and adding C
(when I get to it) will make things even worse. However, for now the
first victim is just the parameter/return value size check.
2024-10-06 14:29:02 +09:00
Bill Currie
d46620fcf4 [qfcc] Add declaration expressions
Now declarations can be deferred too, thus things like generic/template
and inline functions should be possible. However, the most important
thing is this is a step towards a cleaner middle layer for compilation,
separating front-end language from back-end code-gen.
2024-10-04 11:51:34 +09:00
Bill Currie
8b9333e108 [qfcc] Remove union hack for block expressions
I don't remember why I thought it was a good idea at the time, but I
decided that having the union was a bit iffy and making the list
"official" would be a good idea. In the end, it removed a nice chunk of
code (redundant list manipulations).
2024-10-03 19:11:49 +09:00
Bill Currie
56f8e19f63 [qfcc] Implement specialization constants
And they even pass validation (though it turns out there's a bug in
glslangValidator regarding specialization constants with expressions (or
possibly spirv-val, but it seems to be the former as my bug report shows
signs of activity in that direction)).

https://github.com/KhronosGroup/glslang/issues/3748
2024-10-02 02:11:53 +09:00
Bill Currie
a7639a685e [qfcc] Add field and array expression types
And implement enough AST processing to compile fstrianglest.vert

Plenty of code-gen issues, though.
2024-10-02 02:01:33 +09:00
Bill Currie
feca9bd5cb [qfcc] Rename new_field_expr to new_deffield_expr
I want to use new_field_expr for specialized field expressions instead.
However, I don't particularly like new_deffield_expr as a name, but I
can't think of anything better just yet.
2024-10-02 01:52:34 +09:00
Bill Currie
f73e1bf353 [qfcc] Move ctor creation out of class_finish_module
Now, ctor expressions are collected and emitted after all other code,
and the ctor function being created outside of class_finish_module means
it's no longer limited to just class related initialization.
2024-10-01 16:51:49 +09:00
Bill Currie
3af078628e [qfcc] Preserve symbol expressions when constexpr
This prevents them from getting folded out of existence and thus
impossible to specialize.
2024-10-01 14:42:30 +09:00
Bill Currie
fc4e8cb350 [qfcc] Switch to deferred expressions for glsl
I plan to do this eventually for Ruamoko, but I need it to keep working
for now; it's rather nice having multiple languages. I expect this will
open up a lot of options for inlining, generic/template function
instantiation, etc. Right now, it's helping with specialization
constants in glsl.
2024-10-01 14:30:09 +09:00
Bill Currie
eade7e9a85 [qfcc] Add anti-commutative flags for cross and fp sub
They're still not set, but the commutativity can be adjusted
individually.
2024-09-30 19:23:37 +09:00
Bill Currie
594ba86aae [qfcc] Start emitting spir-v expression instructions
They're currently wrong since they're meant to be for specialization
constants (and that whole system is currently broken anyway) but are
instead raw code expressions, but progress is progress.
2024-09-23 18:56:18 +09:00
Bill Currie
5c9ba80d3a [qfcc] Rewrite unary_expr to be more maintainable
Result type and constant handling is now table-driven, resulting in the
removal of seven switch statements (and thus a lot less hassle when
extending types or expressions). Also, (u)long and (u)short are fully
implemented.

In addition, other than result type handing for boolean results, any
back-end specific implementation is now in the back-end.
2024-09-22 16:21:21 +09:00
Bill Currie
8099c4cf8e [qfcc] Support the idea of constexpr
It's nowhere near complete, but unary and binary expressions that are
marked as constant will not be subject to constant folding. This is
necessary for proper support of specialization constants.
2024-09-22 12:28:37 +09:00
Bill Currie
e7710bb7ac [qfcc] Give symtabs a name field
It's currently just to help with debugging now that I've got more
less-random symtabs floating around.
2024-09-21 23:09:38 +09:00
Bill Currie
6e4812f914 [qfcc] Mark symbols as being lvalue or not
This simplifies things a lot and fstrianglest.vert compiles again
(albeit incorrectly).
2024-09-21 22:08:51 +09:00
Bill Currie
2c445380b1 [qfcc] Emit extensions and extinst imports
The imports need their result id recorded somewhere (and the hard-coding
in qc-parse.y removed), but that's a little bit of progress getting
spir-v working.
2024-09-20 14:03:03 +09:00
Bill Currie
1117d31b30 [qfcc] Make some sideways progress with layouts
I'm not sure it's the right directly, and qfcc's internals are starting
to show their age.
2024-09-20 12:24:51 +09:00
Bill Currie
34fc2108ea [qfcc] Use separate symbol types for def and offset
I don't know why I thought it was a good idea to make sy_var context
dependent. Renaming sy_var to sy_def makes it a little easier to know to
use the def field, too.
2024-09-20 11:39:16 +09:00
Bill Currie
6ca06a577a [qfcc] Make capabilities and memory model configurable
While I'm not happy with the module "creation" (at least it's limited to
two places), setting it up with spir-v capabilities and memory model
seems quite nice and should play nicely with being set up from within
source code, though using uint constant expressions might be overkill.
2024-09-20 01:39:44 +09:00
Bill Currie
7931eb8c03 [qfcc] Disable varargs for spirv
I'm not certain supporting varargs in spirv is impossible, but being
able to disable it might be worthwhile anyway.
2024-09-18 14:33:02 +09:00
Bill Currie
ee3a9bd200 [qfcc] Start work on emitting SPIR-V
It's rather non-functional but does so far pass validation via
spirv-val. However, it's showing that qfcc's internals need a lot of
work.
2024-09-17 16:47:19 +09:00
Bill Currie
9cd8bc0d45 [qfcc] Move type encoding defs into an array
This allows the defs to be updated without having to modify the type
struct itself, and also allows for alternative encodings (eg, spir-v).
2024-09-15 12:05:57 +09:00
Bill Currie
c7e35994b5 [qfcc] Give type_t objects unique id indices
This allows indexing into arrays or sets of all types, good for various
mutable information.
2024-09-15 10:29:36 +09:00
Bill Currie
e933eb8fae [qfcc] Clean up expr parenthesis setting
Thare are still many const casts, but this does get rid of one set. I
had tried to replace the paren flag with a () unary expression, but that
brought out a whole pile of places that had problems (especially
anything to do with boolean expressions).
2024-09-14 08:31:26 +09:00
Bill Currie
4c603c3989 [qfcc] Remove rvalue flag from expr_t
It seems it was needed for dealing with the result expression for block
expressions, but it turns out (possibly thanks to dags), that it's easy
to check for the result value and using the appropriate call to emit the
code thus avoiding the non-executable code warning.
2024-09-13 21:41:40 +09:00
Bill Currie
355ee12c3f [qfcc] Give qfo spaces support for names
Fortunately, there was a reserved spot that could be used for the name
thus no need for a version update. The name isn't used yet but will be
for glsl support.
2024-09-12 13:50:33 +09:00
Bill Currie
99be6f6e41 [qfcc] Build namespaces for non-instanced blocks
Each interface type (in, out, uniform etc) gets its own namespace, and
non-instanced blocks get a namespace (their block name) within the
interface namespace.

The defs for the block members are currently "allocated" to be at offset
-1, but the idea is to allow layout qualifiers to know if the member has
already been located.
2024-09-12 13:33:42 +09:00
Bill Currie
db39fdbe37 [qfcc] Create glsl block before parsing members
This allows attributes to be put on the block before members are
declared thus giving member attributes to override block attributes when
appropriate.
2024-09-12 12:14:10 +09:00
Bill Currie
f7f2790937 [qfcc] Use macro magic for the symbol type enum
I found that I'd missed an update or two of the names array.
2024-09-12 12:14:02 +09:00
Bill Currie
f0e770b972 [qfcc] Allow aligned despace allocs to be overridden
GLSL (and in the end, spir-v) needs more control over allocation than
does the Ruamoko VM.
2024-09-10 20:44:51 +09:00
Bill Currie
7742450e03 [qfcc] Do basic error checking on layout qualifiers
I'm not sure I got all the checks right, but bsp_gbuf.geom passes the
validity (but failes due to not having implemented the application of
the qualifiers).
2024-09-10 19:03:13 +09:00
Bill Currie
5d7a8127c2 [qfcc] Add is_handle type check function 2024-09-10 19:00:09 +09:00
Bill Currie
c58748d640 [qfcc] Implement many glsl qualifiers as attributes
Attributes seem appropriate as GLSL's qualifiers affect variables rather
than types (since there's no typedef).

Not much is done with the attributes yet other than some basic error
checking (duplicates of non-layout attributes) and debug output, but
most (if not all) declarations get to the declaration code with
attributes intact.
2024-09-09 20:01:06 +09:00
Bill Currie
7a2027276b [qfcc] Use a separate enum for glsl interfaces
While technically storage classes, they shouldn't pollute other
languages. It's a bit hacky mixing enums in one value, but having some
macros helps.
2024-09-09 11:40:57 +09:00
Bill Currie
55a5782a95 [qfcc] Save the type evaluation code
I don't yet know whether the generated code is correct, but the little
functions that compute a generic type gets stored in the function's
params/return type.
2024-09-07 02:36:54 +09:00
Bill Currie
b59a8fb66a [qfcc] Add a code generator for type expressions
Allows the parsing of the return type in the following:

    @generic(vec=[vec2,vec3,vec4]) {
    @vector(bool,@width(vec)) lessThan(vec x, vec y);
    }

Unfortunately, can't use math in int value parameters just yet, the
processing of expressions needs to be delayed (it's currently done
immediately so type-checking happens to early).

It's not connected up yet, but does produce what looks like the correct
code.
2024-09-06 01:04:38 +09:00
Bill Currie
55d7d1f069 [qfcc] Expose convert_op and ensafen free_operand
Needed for type evaluation codegen, and free_operand needs to be
null-safe.
2024-09-06 01:04:38 +09:00
Bill Currie
9c902501d7 [qfcc] Move D_* macros to def.h
Finally, after way too long.
2024-09-06 00:56:56 +09:00
Bill Currie
65fc6054bb [qfcc] Actually parse ruamoko from strings
The previous related commit was just the basics and only glsl used it,
now ruamoko itself does (really need to look into namings: qc is a bit
off).
2024-09-04 09:35:25 +09:00
Bill Currie
291f920e2a [qfcc] Parse vector literals correctly
It turned out that for v6 progs (due to lack of double or long) weren't
getting correctly parsed vector literals: incorrect "implicit" flag and
then a lot of brittleness around constant value conversions.
2024-09-03 20:50:31 +09:00
Bill Currie
b58e7791fd [qfcc] Implement parameter qualifiers in Ruamoko
Now parameters can be declared `const`, `@in`, `@out`, `@inout`. `@in`
is redundant as it's the default, but I guess it's nice for
self-documenting code. `const` marks the parameter as read-only in the
function, `@out` and `@inout` allow the parameter to pass the value back
out (by copy), but `@out` does not initialize the parameter before
calling and returning without setting an `@out` parameter is an error
(but unfortunately, currently detected only when optimizing).

Unfortunately, it seems to have broken (only!) v6 progs when optimizing
as the second parameter gets optimized out.
2024-09-03 18:07:42 +09:00
Bill Currie
f335540e99 [qfcc] Handle glsl version and extension directives
The version directive really does only some error checking, and
only GL_EXT_multiview and GL_GOOGLE_include_directive are supported for
extensions, but enable/disable work (but not yet warn for multiview).
2024-09-01 17:01:05 +09:00
Bill Currie
cba28e9421 [qfcc] Use correct flags for in and uniform
They're not actually constant (in the usual sense), just read-only.
Fixes an internal error when accessing an unsigned array.
2024-09-01 16:40:47 +09:00
Bill Currie
a24d1d799f [qfcc] Use a stack for cpp_quote_start
Using set_line_file sort of worked with its stack, but line directives
embedded in the source (which glsl's initialization code uses) messed up
the start path for quoted include searches.
2024-08-31 13:01:26 +09:00
Bill Currie
9b2b841a55 [qfcc] Redo interface blocks as namespaces
There's no direct support for namespaces in Ruamoko yet, nor even in
qfcc, but glsl's blocks bring in a bit of foundation for them, even the
concept of "using" (for blocks with no instance name).

The members don't get locations allocated to them yet, but
fstrianglest.vert compiles and links correctly otherwise.

Also, there's no error checking yet.
2024-08-31 10:32:00 +09:00
Bill Currie
ee6e38e2f9 [qfcc] Implement glsl's contructors for math types
I don't think this includes bools yet, and matrices aren't supported
yet, but float vectors work quite nicely.
2024-08-30 13:54:33 +09:00
Bill Currie
d0064c6c46 [qfcc] Implement a lot of glsl semantics
Other than contructors (and problems with the `out` block) qfcc can
compile fstrianglest.vert to what looks like working ruamoko code.
There's still a lot of work to do, though.
2024-08-30 13:51:31 +09:00
Bill Currie
bca4d0e794 [qfcc] Implement location printing for the parsers
It's pretty bare-bones, but it's at least consistent across all the
parsers, and it's currently used only by the parser debug support.
2024-08-30 13:13:13 +09:00
Bill Currie
b302ce1095 [qfcc] Hook up glsl builtin variables
They get parsed, but nothing gets defined yet, but this proved to be a
good test for rua_parse_string().
2024-08-28 13:53:30 +09:00
Bill Currie
de6a3c5702 [qfcc] Support parsing Ruamoko from strings
Handy for parsing builtin symbols for things like glsl.
2024-08-28 13:50:36 +09:00
Bill Currie
4be1384701 [qfcc] Improve language selection
Using a struct with function pointers instead of switching on an enum
makes it much easier to add languages and, more importantly,
sub-languages like glsl's shader stage variants.
2024-08-28 10:18:21 +09:00
Bill Currie
27286389d1 [qfcc] Isolate functions from symbols
Symbols now use metafunc_t to reference functions, which should make
working with generic and overloaded functions easier.
2024-08-26 15:50:27 +09:00
Bill Currie
8eae02209e [qfcc] Unify qc and c function symbol handling
This gets all the function symbol type handling into the one place,
which will make dealing with generic functions much easier.
2024-08-26 12:58:39 +09:00
Bill Currie
6a70ecda9d [qfcc] Make default_type take const symbol_t
It doesn't need to modify sym, and being const makes it more clear that
it doesn't (despite some of the other type functions breaking that rule,
ugh).
2024-08-21 08:30:15 +09:00
Bill Currie
219f2f26da [qfcc] Add is_double_val check
I wound up not using it, but I'll probably want it eventually..
2024-08-20 15:16:25 +09:00