964 Commits

Author SHA1 Message Date
Craig Topper
ee9cbe3548 [RISCV] Move RISCV::RVVBitsPerBlock from TargetParser to Support/RISCVISAInfo.h.
RISCVTargetParser.h has a dependency on a tablegen generated file.

Using RISCVISAInfo.h instead avoids this dependency.

We just need this constant somewhere visible to the frontend and
backend and I'm trying to avoid adding a header just for it.
2023-04-29 15:04:55 -07:00
Craig Topper
42e79d9771 [RISCV] Add attribute(riscv_rvv_vector_bits(N)) based on AArch64 arm_sve_vector_bits.
This allows the user to set the size of the scalable vector so they
can be used in structs and as the type of global variables. This works
by representing the type as a fixed vector instead of a scalable vector
in IR. Conversions to and from scalable vectors are made where necessary
like function arguments/returns and intrinsics.

This features has been requested here
https://github.com/riscv-non-isa/rvv-intrinsic-doc/issues/176
I know arm_sve_vector_bits is used by the Eigen library so this
could be used to port Eigen to RVV.

This patch adds a new preprocessor define `__riscv_v_fixed_vlen` that
is set when -mrvv_vector_bits is passed on the command line.

The code is largely based on the AArch64 code. A lot of code was
copy/pasted and then modiied to RVV. There may be some opportunities
for sharing.

This first patch only supports the LMUL=1 types. Additional changes
will be needed to support other LMULs. I have also not supported
mask vectors.

Differential Revision: https://reviews.llvm.org/D145088
2023-04-28 15:41:17 -07:00
Craig Topper
05d0caef60 [RISCV] Remove support for attribute interrupt("user").
This was part of the N extension which didn't make it version
1.12 of the privilege specification.

Reviewed By: kito-cheng

Differential Revision: https://reviews.llvm.org/D149314
2023-04-27 08:21:36 -07:00
Dominik Adamski
f900567678 [OpenMP][AMDGPU] Refactor setting uniform work group size attribute
Work group size attribute was set in Clang specific class. That's why
we cannot reuse this code in Flang.

If we move setting of this attribute to OpenMPIRBuilder, then we can reuse this
code in Flang and Clang. Function createOffloadEntry from OpenMPIRBuilder is
already used by Clang (via OpenMPIRBuilder::createOffloadEntriesAndInfoMetadata
function).

Differential Revision: https://reviews.llvm.org/D148525

Reviewed By: jdoerfert
2023-04-21 01:35:39 -05:00
Manna, Soumi
18a3d9e5b3 [NFC][clang] Fix coverity static analyzer concerns about AUTO_CAUSES_COPY
Reported by Coverity:

AUTO_CAUSES_COPY
Unnecessary object copies can affect performance.

1. [NFC] Fix auto keyword use without an & causes the copy of an object of type SimpleRegistryEntry in clang::getAttributePluginInstances()

2. [NFC] Fix auto keyword use without an & causes the copy of an object of type tuple in CheckStmtInlineAttr<clang::NoInlineAttr, 2>(clang::Sema &, clang::Stmt const *, clang::Stmt const *, clang::AttributeCommonInfo const &)

3. [NFC] Fix auto keyword use without an & causes the copy of an object of type QualType in <unnamed>::SystemZTargetCodeGenInfo::isVectorTypeBased(clang::Type const *, bool)

4. [NFC] Fix auto keyword use without an & causes the copy of an object of type Policy in <unnamed>::RISCVIntrinsicManagerImpl::InitIntrinsicList()

5. [NFC] Fix auto keyword use without an & causes the copy of an object of type pair in checkUndefinedButUsed(clang::Sema &)

Reviewed By: tahonermann

Differential Revision: <https://reviews.llvm.org/D147543>
2023-04-17 21:33:21 -04:00
David Tenty
2fe49ea0d0 [clang][PowerPC] Remove remaining Darwin support
POWER Darwin support in the backend has been removed for some time: https://discourse.llvm.org/t/rfc-remove-darwin-support-from-power-backends
but Clang still has the TargetInfo and other remnants lying around.

This patch does some cleanup and removes those and other related frontend support still remaining. We adjust any tests using the triple to either remove
the test if unneeded or switch to another Power triple.

Reviewed By: MaskRay, nemanjai

Differential Revision: https://reviews.llvm.org/D146459
2023-03-28 17:12:49 -04:00
Juan Manuel MARTINEZ CAAMAÑO
488185cca3 [Clang][DebugInfo][AMDGPU] Emit zero size bitfields in the debug info to delimit bitfields in different allocation units.
Consider the following sturctures when targetting:

  struct foo {
    int space[4];
    char a : 8;
    char b : 8;
    char x : 8;
    char y : 8;
  };

  struct bar {
    int space[4];
    char a : 8;
    char b : 8;
    char : 0;
    char x : 8;
    char y : 8;
  };

Even if both structs have the same layout in memory, they are handled
differenlty by the AMDGPU ABI.

With the following code:

// clang --target=amdgcn-amd-amdhsa -g -O1 example.c -S
char use_foo(struct foo f) { return f.y; }
char use_bar(struct bar b) { return b.y; }

For use_foo, the 'y' field is passed in v4
; v_ashrrev_i32_e32 v0, 24, v4
; s_setpc_b64 s[30:31]

For use_bar, the 'y' field is passed in v5
; v_bfe_i32 v0, v5, 8, 8
; s_setpc_b64 s[30:31]

To make this distinction, we record a single 0-size bitfield for every member that is preceded
by it.

Reviewed By: probinson

Differential Revision: https://reviews.llvm.org/D144870
2023-03-28 10:07:32 +02:00
Craig Topper
29463612d2 [RISCV] Replace RISCV -> RISC-V in comments. NFC
To be consistent with RISC-V branding guidelines
https://riscv.org/about/risc-v-branding-guidelines/
Think we should be using RISC-V where possible.

More patches will follow.

Reviewed By: asb

Differential Revision: https://reviews.llvm.org/D146449
2023-03-27 09:50:17 -07:00
Alex Bradbury
938deaad8a [clang][RISCV] Fix ABI lowering for _Float16 for FP ABIs
For trivial cases (`_Float16` as a standalone argument), it was
previously correctly lowered to half. But the logic for catching cases
involving structs was gated off, as at the time that logic was written
the ABI for half was unclear.

This patch fixes that and adds a release note.

Differential Revision: https://reviews.llvm.org/D145074
2023-03-26 16:18:47 +01:00
Joseph Huber
29a5c3c8fe [NVPTX] Introduce attribute to mark kernels without a language mode
We may want to be able to mark certain regions as kernels even without
being in an accepted CUDA or OpenCL language mode. This patch introduces
a new attribute limited to `nvptx` targets called `nvptx_kernel` which
will perform the same metadata action as the existing CUDA ones. This
closely mimics the behaviour of the `amdgpu_kernel` attribute. This
allows for making executable NVPTX device images without using an
existing offloading language model.

I was unsure how to do this, I could potentially re-use all the CUDA
attributes and just replace the `CUDA` language requirement with an
`NVPTX` architecture requirement. Also I don't know if I should add more
than just this attribute.

Reviewed By: tra

Differential Revision: https://reviews.llvm.org/D140226
2023-03-24 14:42:25 -05:00
Pavel Kosov
28997feb0c [LLVM][OHOS] Clang toolchain and targets
Add a clang part of OpenHarmony target

Related LLVM part: D138202

~~~

Huawei RRI, OS Lab

Reviewed By: DavidSpickett

Differential Revision: https://reviews.llvm.org/D145227
2023-03-20 12:53:24 +03:00
Paulo Matos
8d0c889752 [clang][WebAssembly] Initial support for reference type funcref in clang
This is the funcref counterpart to 890146b. We introduce a new attribute
that marks a function pointer as a funcref. It also implements builtin
__builtin_wasm_ref_null_func(), that returns a null funcref value.

Differential Revision: https://reviews.llvm.org/D128440
2023-03-17 18:31:44 +01:00
Matt Arsenault
8e009348e8 clang: Use ptrmask for pointer alignment
Avoid using ptrtoint/inttoptr.
2023-03-16 07:16:41 -04:00
Hans Wennborg
7a85aa918c Emit const globals with constexpr destructor as constant LLVM values
This follows 2b4fa53 which made Clang not emit destructor calls for such
objects. However, they would still not get emitted as constants since
CodeGenModule::isTypeConstant() returns false if the destructor is
constexpr. This change adds a param to make isTypeConstant() ignore the
dtor, allowing the caller to check it instead.

Fixes Issue #61212

Differential revision: https://reviews.llvm.org/D145369
2023-03-16 11:02:27 +01:00
Daniel Thornburgh
d505d20a62 Revert "[LLVM][OHOS] Clang toolchain and targets"
This change had tests that break whenever LLVM_ENABLE_LINKER_BUILD_ID is
set, as is the case in the Fuchsia target.

This reverts commits:
f81317a54586dbcef0c14cf512a0770e8ecaab3d
72474afa27570a0a1307f3260f0187b703aa6d84
2023-03-14 13:46:21 -07:00
Pavel Kosov
72474afa27 [LLVM][OHOS] Clang toolchain and targets
Add a clang part of OpenHarmony target

Related LLVM part: D138202

~~~

Huawei RRI, OS Lab

Reviewed By: DavidSpickett

Differential Revision: https://reviews.llvm.org/D145227
2023-03-14 12:24:44 +03:00
Joshua Cranmer
bcad161db3 [Clang][SPIR-V] Emit target extension types for OpenCL types on SPIR-V.
Reviewed By: Anastasia

Differential Revision: https://reviews.llvm.org/D141008
2023-03-13 14:20:24 -04:00
Brad Smith
2a2c0fd967 [Driver][FreeBSD] Correct driver behavior if a triple is provided without a version
While looking at other usage of getOSMajorVersion() I noticed if a version number is not
included in the FreeBSD triple it won't include the --hash-style=both linker option or
not disable the use of .init_array. Without a version should be the latest.

FreeBSD 8 and 9 are no longer supported. So simplify things with the version handling
as well.

Reviewed By: dim

Differential Revision: https://reviews.llvm.org/D144341
2023-02-21 14:08:26 -05:00
Paulo Matos
890146b192 [WebAssembly] Initial support for reference type externref in clang
This patch introduces a new type __externref_t that denotes a WebAssembly opaque
reference type. It also implements builtin __builtin_wasm_ref_null_extern(),
that returns a null value of __externref_t. This lays the ground work
for further builtins and reference types.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D122215
2023-02-17 18:48:48 -08:00
Archibald Elliott
62c7f035b4 [NFC][TargetParser] Remove llvm/ADT/Triple.h
I also ran `git clang-format` to get the headers in the right order for
the new location, which has changed the order of other headers in two
files.
2023-02-07 12:39:46 +00:00
Vitaly Buka
bccf5999d3 Revert "[clang][WebAssembly] Initial support for reference type externref in clang"
Very likely breaks stage 3 of msan build bot.
Good: 764c88a50ac76a2df2d051a0eb5badc6867aabb6 https://lab.llvm.org/buildbot/#/builders/74/builds/17058
Looks unrelated: 48b5a06dfcab12cf093a1a3df42cb5b684e2be4c
Bad: 48b5a06dfcab12cf093a1a3df42cb5b684e2be4c https://lab.llvm.org/buildbot/#/builders/74/builds/17059

This reverts commit eb66833d19573df97034a81279eda31b8d19815b.
2023-02-05 21:41:48 -08:00
Paulo Matos
eb66833d19 [clang][WebAssembly] Initial support for reference type externref in clang
This patch introduces a new type __externref_t that denotes a WebAssembly opaque
reference type. It also implements builtin __builtin_wasm_ref_null_extern(),
that returns a null value of __externref_t. This lays the ground work
for further builtins and reference types.

Differential Revision: https://reviews.llvm.org/D122215
2023-01-31 17:34:01 +01:00
Matt Arsenault
647925648a clang/OpenCL: Apply default attributes to enqueued blocks
This was missing important environment context, like denormal-fp-math
and target-features. Curiously this seems to be losing nounwind. Note
this only fixes the actual invoke kernel. The invoke function is
already setting the default attribute set for internal
functions. However that is still buggy since it's not applying any use
function attributes (it's also missing uniform-work-group-size).

There seem to be too many different functions for setting attributes
with inconsistent behavior. The Function overload of
addDefaultFunctionAttributes seems to miss the target-cpu and
target-features. The AttrBuilder one seems to miss optnone (but that
seems to be disallowed on blocks anyway). Neither one calls
setTargetAttributes, when it probably should. uniform-work-group-size
is also set through AMDGPU code when it should be emitting generically
as a language property.

I also noticed update_cc_test_checks for attributes seem to not
connect the captured attribute variables to the attributes at the end
(although I think the numbers happen to work out correctly).
2023-01-30 15:03:15 -04:00
Matt Arsenault
00f6a7f02f clang/OpenCL: Fix not setting convergent on block invoke kernels
Yet another example how convergent not being the default is dangerous
and backwards.
2023-01-30 15:03:14 -04:00
Matt Arsenault
52c28d7cf9 clang/OpenCL: Don't use a Function for the block type
The AMDGPU value for this is not really a function. Currently we're
emitting IR that isn't true to what will eventually be emitted.
2023-01-30 15:03:14 -04:00
Kazu Hirata
526966d07d Use llvm::bit_ceil (NFC)
Note that:

  std::has_single_bit(X) ? X : llvm::NextPowerOf2(X);

is equivalent to:

  std::bit_ceil(X)

even for input 0.
2023-01-28 16:13:09 -08:00
Jonas Paulsson
0eff46f87f [SystemZ] Fix handling of vectors and their exposure of the vector ABI.
- Global vector variables expose the vector ABI through their alignments only
  if they are >=16 bytes in size.

- Vectors passed between functions expose the vector ABI only if they are
  <=16 bytes in size.

LLVM test suite builds with gcc/clang now give the same gnu attributes emitted.

Reviewed By: Ulrich Weigand

Differential Revision: https://reviews.llvm.org/D141409
2023-01-27 20:24:09 +01:00
Alex Bradbury
e0a28188d2 [clang][RISCV] Fix ABI mismatch between GCC and Clang (extension of integers on stack)
See <https://github.com/llvm/llvm-project/issues/57261> for full
details. Essentially, a previous version of the psABI indicated (by my
reading) that integer scalars passed on the stack were anyext. A [later
commit](cec39a064e)
changed this to indicate that they are in fact signext/zeroext just as
if they were passed in registers.

This patch adds the change in the release notes but doesn't add a flag
to retain the old behaviour. The hope is that it's sufficiently hard to
trigger an issue due to this that it isn't worthwhile doing so.

Differential Revision: https://reviews.llvm.org/D140401
2023-01-24 14:20:28 +00:00
Guillaume Chatelet
bf5c17ed0f [clang][NFC] Remove dependency on DataLayout::getPrefTypeAlignment 2023-01-13 15:01:29 +00:00
Guillaume Chatelet
6916ebd026 [clang][NFC] Use the TypeSize::getXXXValue() instead of TypeSize::getXXXSize)
This change is one of a series to implement the discussion from
https://reviews.llvm.org/D141134.
2023-01-11 16:07:48 +00:00
serge-sans-paille
a3c248db87
Move from llvm::makeArrayRef to ArrayRef deduction guides - clang/ part
This is a follow-up to https://reviews.llvm.org/D140896, split into
several parts as it touches a lot of files.

Differential Revision: https://reviews.llvm.org/D141139
2023-01-09 12:15:24 +01:00
Matt Arsenault
270e96f435 Revert "AMDGPU: Invert handling of enqueued block detection"
This reverts commit 47288cc977fa31c44cc92b4e65044a5b75c2597e.

The runtime is having trouble with this at -O0 when the inputs are
always enabled.
2023-01-07 21:48:07 -05:00
Matt Arsenault
6fe70cb465 clang/AMDGPU: Force disable block enqueue arguments for HIP
This is a dirty, dirty hack to workaround bot failures at
-O0. Currently these fields are only used by OpenCL features and
evidently the HIP runtime isn't expecting to see them in HIP
programs. The code objects should be language agnostic, so just force
optimize these out until the runtime is fixed.
2023-01-07 13:39:05 -05:00
Ben Shi
b2638a7a34 [clang] Do not extend i8 return values to i16 on AVR.
Reviewed By: Miss_Grape, aykevl

Differential Revision: https://reviews.llvm.org/D139908
2022-12-21 20:33:49 +08:00
yronglin
ebe530ef7a [CodeGen][AArch64] Fix AArch64ABIInfo::EmitAAPCSVAArg crash with empty record type in variadic arg
Fix AArch64ABIInfo::EmitAAPCSVAArg crash with empty record type in variadic arg

Open issue: https://github.com/llvm/llvm-project/issues/59034

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D138511
2022-12-20 22:06:01 +08:00
Jonas Paulsson
481bb44baa [SystemZ] Emit a .gnu_attribute for an externally visible vector abi.
On SystemZ, the vector ABI changes depending on the presence of hardware
vector support. Therefore, each binary compiled with a visible vector ABI
(e.g. one that calls an external function with a vector argument) should be
marked with a .gnu_attribute describing this.

Reviewed By: uweigand

Differential Revision: https://reviews.llvm.org/D105067
2022-12-06 12:53:40 -06:00
Alex Richardson
a602f76a24 [clang][TargetInfo] Use LangAS for getPointer{Width,Align}()
Mixing LLVM and Clang address spaces can result in subtle bugs, and there
is no need for this hook to use the LLVM IR level address spaces.
Most of this change is just replacing zero with LangAS::Default,
but it also allows us to remove a few calls to getTargetAddressSpace().

This also removes a stale comment+workaround in
CGDebugInfo::CreatePointerLikeType(): ASTContext::getTypeSize() does
return the expected size for ReferenceType (and handles address spaces).

Differential Revision: https://reviews.llvm.org/D138295
2022-11-30 20:24:01 +00:00
yronglin
80f444646c [CodeGen][ARM] Fix ARMABIInfo::EmitVAAarg crash with empty record type variadic arg
Fix ARMABIInfo::EmitVAAarg crash with empty record type variadic arg

Open issue: https://github.com/llvm/llvm-project/issues/58794

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D138137
2022-11-19 15:14:10 +08:00
Ben Shi
84ef723573 [clang] Fix wrong ABI of AVRTiny.
A scalar which exceeds 4 bytes should be returned via a stack slot,
on an AVRTiny device.

Reviewed By: aykevl

Differential Revision: https://reviews.llvm.org/D138125
2022-11-17 08:38:44 +08:00
Rageking8
94738a5ac3 Fix duplicate word typos; NFC
This revision fixes typos where there are 2 consecutive words which are
duplicated. There should be no code changes in this revision (only
changes to comments and docs). Do let me know if there are any
undesirable changes in this revision. Thanks.
2022-11-08 07:21:23 -05:00
Xiang Li
464926ef44 [HLSL] Disable integer promotion to avoid int16_t being promoted to int for HLSL.
short will be promoted to int in UsualUnaryConversions.
Disable it for HLSL to keep int16_t as 16bit.

Reviewed By: aaron.ballman, rjmccall

Differential Revision: https://reviews.llvm.org/D133668
2022-10-20 16:06:25 -07:00
Ting Wang
ee703b5cb1 [clang][PowerPC] PPC64 VAArg fix right-alignment for aggregates fit in register
PPC64 ABI pass aggregates smaller than a register into the least
significant bits of the register. In the case of variadic functions,
they will end up right-aligned in their argument slots in the argument
area on big-endian targets. Apply right-alignment for these aggregates.

Fixes #55900.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D133338
2022-10-16 22:01:47 -04:00
Kazu Hirata
647e48cf5f [clang] Use std::clamp (NFC)
Note that the constructor of MipsABIInfo guarantees that
MinABIStackAlignInBytes <= StackAlignInBytes, so we can use std::clamp
safely.
2022-10-16 10:11:29 -07:00
Joseph Huber
4aa87a131f [OpenMP][AMDGPU] Add 'uniform-work-group' attribute to OpenMP kernels
The `cl-uniform-work-group` attribute asserts that the global work-size
be a multiple of the work-group specified work group size. This should
allow optimizations. It is already present by default in the AMD
compiler and for HIP kernels so it should be safe to allow this for
OpenMP kernels by default.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D135374
2022-10-06 18:22:09 -05:00
David Green
781b491bba [Clang][AArch64] Support AArch64 target(..) attribute formats.
This adds support under AArch64 for the target("..") attributes. The
current parsing is very X86-shaped, this patch attempts to bring it line
with the GCC implementation from
https://gcc.gnu.org/onlinedocs/gcc/AArch64-Function-Attributes.html#AArch64-Function-Attributes.

The supported formats are:
- "arch=<arch>" strings, that specify the architecture features for a
  function as per the -march=arch+feature option.
- "cpu=<cpu>" strings, that specify the target-cpu and any implied
  atributes as per the -mcpu=cpu+feature option.
- "tune=<cpu>" strings, that specify the tune-cpu cpu for a function as
  per -mtune.
- "+<feature>", "+no<feature>" enables/disables the specific feature, for
  compatibility with GCC target attributes.
- "<feature>", "no-<feature>" enabled/disables the specific feature, for
  backward compatibility with previous releases.

To do this, the parsing of target attributes has been moved into
TargetInfo to give the target the opportunity to override the existing
parsing. The only non-aarch64 change should be a minor alteration to the
error message, specifying using "CPU" to describe the cpu, not
"architecture", and the DuplicateArch/Tune from ParsedTargetAttr have
been combined into a single option.

Differential Revision: https://reviews.llvm.org/D133848
2022-10-01 15:40:59 +01:00
Phoebe Wang
46bb4b99ae [X86][fastcall][vectorcall] Move capability check before free register update
When passing arguments with `__fastcall` or `__vectorcall` in 32-bit MSVC, the following arguments have chance to be passed by register if the current one failed. `__regcall` from ICC is on the contrary: https://godbolt.org/z/4MPbzhaMG
All the three calling conversions are not supported in GCC.

Fixes: #57737

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D133920
2022-09-20 09:18:23 +08:00
Weining Lu
7d88a05cc0 [Clang][LoongArch] Implement ABI lowering
Reuse most of RISCV's implementation with several exceptions:

1. Assign signext/zeroext attribute to args passed in stack.
On RISCV, integer scalars passed in registers have signext/zeroext
when promoted, but are anyext if passed on the stack. This is defined
in early RISCV ABI specification. But after this change [1], integers
should also be signext/zeroext if passed on the stack. So I think
RISCV's ABI lowering should be updated [2].

While in LoongArch ABI spec, we can see that integer scalars narrower
than GRLEN bits are zero/sign-extended no matter passed in registers
or on the stack.

2. Zero-width bit fields are ignored.
This matches GCC's behavior but it hasn't been documented in ABI sepc.
See https://gcc.gnu.org/r12-8294.

3. `char` is signed by default.
There is another difference worth mentioning is that `char` is signed
by default on LoongArch while it is unsigned on RISCV.

This patch also adds `_BitInt` type support to LoongArch and handle it
in LoongArchABIInfo::classifyArgumentType.

[1] cec39a064e
[2] https://github.com/llvm/llvm-project/issues/57261

Differential Revision: https://reviews.llvm.org/D132285
2022-09-19 12:05:00 +08:00
Kazu Hirata
86bc4587e1 Use std::clamp (NFC)
This patch replaces clamp idioms with std::clamp where the range is
obviously valid from the source code (that is, low <= high) to avoid
introducing undefined behavior.
2022-08-27 09:53:13 -07:00
Kazu Hirata
8e494b85a5 Use llvm::drop_begin (NFC) 2022-08-20 21:18:30 -07:00
Alex Bradbury
bc53832080 [clang][RISCV] Fix incorrect ABI lowering for inherited structs under hard-float ABIs
The hard float ABIs have a rule that if a flattened struct contains
either a single fp value, or an int+fp, or fp+fp then it may be passed
in a pair of registers (if sufficient GPRs+FPRs are available).
detectFPCCEligibleStruct and the helper it calls,
detectFPCCEligibleStructHelper examine the type of the argument/return
value to determine if it complies with the requirements for this ABI
rule.

As reported in bug #57084, this logic produces incorrect results for C++
structs that inherit from other structs. This is because only the fields
of the struct were examined, but enumerating RD->fields misses any
fields in inherited C++ structs. This patch corrects that issue by
adding appropriate logic to enumerate any included base structs.

Differential Revision: https://reviews.llvm.org/D131677
2022-08-19 20:31:06 +01:00