6982 Commits

Author SHA1 Message Date
Craig Topper
95aab69c10
[RISCV] Remove experimental from Zacas. (#83195)
Document that we don't use the double compare and swap instructions due
to ABI concerns.
2024-02-28 21:46:58 -08:00
Micah Weston
9ca8db352d
[SHT_LLVM_BB_ADDR_MAP] Adds pretty printing of BFI and BPI for PGO Analysis Map in tools. (#82292)
Primary change is to add a flag `--pretty-pgo-analysis-map` to
llvm-readobj and llvm-objdump that prints block frequencies and branch
probabilities in the same manner as BFI and BPI respectively. This can
be helpful if you are manually inspecting the outputs from the tools.

In order to print, I moved the `printBlockFreqImpl` function from
Analysis to Support and renamed it to `printRelativeBlockFreq`.
2024-02-27 14:13:00 -05:00
cpsughrue
f410f74cd5 Revert "[llvm][Support] Add support for executing a detached process (#81708)"
This reverts commit 86f6caa562255f81b93e72a501a926b17f5ad244. Unit test
was failing on a few windows build bots
2024-02-26 21:40:21 -05:00
Connor Sughrue
86f6caa562
[llvm][Support] Add support for executing a detached process (#81708)
Adds a new parameter, `bool DetachProcess` with a default option of
`false`, to `llvm::sys::ExecuteNoWait`, which, when set to `true`,
executes the specified program without a controlling terminal.

Functionality added so that the module build daemon can be run without a
controlling terminal.
2024-02-26 21:04:11 -05:00
PiJoules
ad49657a42
[clang] Add fixed point precision macros (#81207)
This defines the builtin macros specified in `7.18a.3 Precision macros`
of ISO/IEC TR 18037:2008. These are the `__*__` versions of them and the
formal definitions in stdfix.h can use them.
2024-02-14 14:11:56 -08:00
Michael Spencer
edff3ff4d3
[llvm][Support] Add ExponentialBackoff helper (#81206)
This provides a simple way to implement exponential backoff using a do
while loop.

Usage example (also see the change to LockFileManager.cpp):
```
ExponentialBackoff Backoff(10s);
do {
  if (tryToDoSomething())
    return ItWorked;
} while (Backoff.waitForNextAttempt());
return Timeout;
```

Abstracting this out of `LockFileManager` as the module build daemon
will need it.
2024-02-13 18:35:39 -08:00
Jay Foad
5e5e51e906 Make use of std::inserter. NFC. 2024-02-13 14:34:58 +00:00
Arthur Eubanks
93cdd1b5cf
[PGO] Add ability to mark cold functions as optsize/minsize/optnone (#69030)
The performance of cold functions shouldn't matter too much, so if we
care about binary sizes, add an option to mark cold functions as
optsize/minsize for binary size, or optnone for compile times [1]. Clang
patch will be in a future patch.

This is intended to replace `shouldOptimizeForSize(Function&, ...)`.
We've seen multiple cases where calls to this expensive function, if not
careful, can blow up compile times. I will clean up users of that
function in a followup patch.

Initial version: https://reviews.llvm.org/D149800

[1]
https://discourse.llvm.org/t/rfc-new-feature-proposal-de-optimizing-cold-functions-using-pgo-info/56388
2024-02-12 14:52:08 -08:00
Craig Topper
2faeea313f
[RISCV] Add Ssqosid support to -march. (#80747) 2024-02-06 10:06:01 -08:00
Michael Maitland
0bf165e383
[RISCV] Add support for RISC-V Pointer Masking (#79929)
This patch implements the v0.8.1 specification. This patch reports
version 0.8 in llvm since `RISCVISAInfo::ExtensionVersion` only has a
`Major` and `Minor` version number. This patch includes includes support
of the `Ssnpm`, `Smnpm`, `Smmpm`, `Sspm` and `Supm` extensions that make
up RISC-V pointer masking.

All of these extensions require emitting attribute containing correct
`march` string.

`Ssnpm`, `Smnpm`, `Smmpm` extensions introduce a 2-bit WARL field (PMM).
The extension does not specify how PMM is set, and therefore this patch
does not need to address this. One example of how it *could* be set is
using the Zicsr instructions to update the PMM bits of the described
registers.

The full specification can be found at
https://github.com/riscv/riscv-j-extension/blob/master/zjpm-spec.pdf
2024-02-05 13:56:25 -05:00
Kazu Hirata
90e9c6e36e [llvm] Use StringRef::consume_front (NFC) 2024-02-04 14:57:25 -08:00
Kazu Hirata
8926af426f [Support] Use StringRef::starts_with (NFC) 2024-02-03 09:36:45 -08:00
David Blaikie
f6b387589d Reapply "lldb: Cache string hash during ConstString pool queries/insertions"
Reverted due to an internally discovered lld crash due to the underlying
StringMap changes, which turned out to be an existing lld bug that got
tickled by the StringMap changes. That's addressed in
dee8786f70a3d62b639113343fa36ef55bdbad63 so let's have another go with
this change.

Original commit message:
    lldb was rehashing the string 3 times (once to determine which StringMap
    to use, once to query the StringMap, once to insert) on insertion (twice
    on successful lookup).

    This patch allows the lldb to benefit from hash improvements in LLVM
    (from djbHash to xxh3).

    Though further changes would be needed to cache this value to disk - we
    shouldn't rely on the StringMap::hash remaining the same in the
    future/this value should not be serialized to disk. If we want cache
    this value StringMap should take a hashing template parameter to allow
    for a fixed hash to be requested.

This reverts commit 5bc1adff69315dcef670e9fcbe04067b5d5963fb.
Effectively reapplying the original 2e197602305be18b963928e6ae024a004a95af6d.
2024-02-02 20:01:51 +00:00
David Blaikie
9a4a4c3f74 Reapply "[ADT][StringMap] Add ability to precompute and reuse the string hash"
Reverted due to an internally discovered lld crash, which turned out to
be an existing lld bug that got tickled by this changes. That's
addressed in dee8786f70a3d62b639113343fa36ef55bdbad63 so let's have
another go with this change.

Original commit message:
    Useful for lldb's const string pool, using the hash to determine which
    string map to lock and query/insert.

    Derived from https://reviews.llvm.org/D122974 by Luboš Luňák

This reverts commit f976719fb2cb23364957e5993f7fc3684ee15391.
Effectively reapplying 67c631d283fc96d652304199cd625be426b98f8e.
2024-02-02 20:01:51 +00:00
Craig Topper
58c494f47c
[RISCV] Add -march support for many of the S extensions mentioned in the profile specification. (#79399)
This is a good portion of the extensions mentioned in the RVA23 profile
here
https://github.com/riscv/riscv-profiles/blob/main/rva23-profile.adoc

I don't believe these add any new CSRs. Sstc does add new CSRs, but we
already added them without the extension name a while back.

I tried to keep the descriptions in RISCVFeatures.td fairly short since
the strings show up in `-print-supported-extensions`.
2024-02-01 18:50:30 -08:00
Brendan Sweeney
e296cedcd6
[RISCV][MC] MC layer support for the experimental zalasr extension (#79911)
This PR implements experimental support for the RISC-V Atomic
Load-Acquire and Store-Release Extension (Zalasr). It has been approved
to be pursued as a fast track extension
(https://lists.riscv.org/g/tech-unprivileged/topic/arc_architecture_review/101951698),
but has not yet been approved by ARC or ratified. See
https://github.com/mehnadnerd/riscv-zalasr for draft spec.

---------

Co-authored-by: brs <turtwig@utexas.edu>
Co-authored-by: Philip Reames <preames@rivosinc.com>
2024-02-01 10:58:21 -08:00
Kazu Hirata
39fa304866 [llvm] Use StringRef::starts_with (NFC) 2024-01-31 23:54:07 -08:00
Timm Baeder
24a804101b
[llvm][Support] Support bright colors in raw_ostream (#80017) 2024-01-31 11:14:02 +01:00
Yingwei Zheng
89f87c3876
[RISCV][MC] Add MC layer support for the experimental zabha extension (#80005)
This patch implements the zabha (Byte and Halfword Atomic Memory
Operations) v1.0-rc1 extension.
See also https://github.com/riscv/riscv-zabha/blob/v1.0-rc1/zabha.adoc.
2024-01-31 17:06:43 +08:00
Michael Spencer
7847e44594
[clang][DependencyScanner] Remove unused -ivfsoverlay files (#73734)
`-ivfsoverlay` files are unused when building most modules. Enable
removing them by,
* adding a way to visit the filesystem tree with extensible RTTI to
  access each `RedirectingFileSystem`.
* Adding tracking to `RedirectingFileSystem` to record when it
  actually redirects a file access.
* Storing this information in each PCM.

Usage tracking is only enabled when iterating over the source manager
and affecting modulemaps. Here each path is stated to cause an access.
During scanning these stats all hit the cache.
2024-01-30 15:39:18 -08:00
Craig Topper
2e165009b7
[RISCV] Use Twine concatentation for error messages in RISCVISAInfo. (#79956)
This avoids converting StringRef to std::string to const char*.
2024-01-30 10:24:54 -08:00
Piyou Chen
7dc7fc0843 Recommit "[RISCV] Relax march string order constraint (#78120)"
With std::move added to fix build bot failure.

Original commit message:

Follow
https://github.com/riscv-non-isa/riscv-toolchain-conventions/pull/14 by
dropping the order requirement of `-march`.

1. single-letter extension can be arbitrary order
    - march=rv32iamdf
2. single-letter extension and multi-letter extension can be mixed
    - march=rv32i_zihintntl_m_a_f_d_svinval
3. multi-letter extension need seperate the following extension by
underscore, otherwise it will be intreprete as one extension.
    - march=rv32i_zbam -> i,zbam
    - march=rv32i_zba_m -> i,zba,m
2024-01-30 10:24:14 -08:00
Mehdi Amini
5a00cb1abf
Revert "[RISCV] Relax march string order constraint" (#79976)
Reverts llvm/llvm-project#78120

Buildbot is broken:

llvm/lib/Support/RISCVISAInfo.cpp:910:18: error: call to deleted
constructor of 'llvm::Error'
          return E;
                 ^
2024-01-30 02:32:52 -08:00
Piyou Chen
d09082f6fd
[RISCV] Relax march string order constraint (#78120)
Follow
https://github.com/riscv-non-isa/riscv-toolchain-conventions/pull/14 by
dropping the order requirement of `-march`.

1. single-letter extension can be arbitrary order
    - march=rv32iamdf 
2. single-letter extension and multi-letter extension can be mixed
    - march=rv32i_zihintntl_m_a_f_d_svinval
3. multi-letter extension need seperate the following extension by
underscore, otherwise it will be intreprete as one extension.
    - march=rv32i_zbam -> i,zbam
    - march=rv32i_zba_m -> i,zba,m
2024-01-30 14:33:52 +08:00
Alex Bradbury
d833b9d677
[RISCV] Graduate Zicond to non-experimental (#79811)
The Zicond extension was ratified in the last few months, with no
changes that affect the LLVM implementation. Although there's surely
more tuning that could be done about when to select Zicond or not, there
are no known correctness issues. Therefore, we should mark support as
non-experimental.
2024-01-29 15:58:54 +00:00
Craig Topper
86b3f8518f [RISCV] Used Twine concatenation instead of format strings RISCVISAInfo.cpp. NFC
We were converting several StringRefs to std::strings then to
char * so we could pass as %s to a format string. Use the Twine
signature of createStringError instead.
2024-01-28 20:03:53 -08:00
Brandon Wu
8e01042da9
[RISCV] Add missing dependency check for Zvkb (#79467) 2024-01-26 11:14:43 +08:00
Wang Pengcheng
1a14c446dd
[RISCV][MC] Add experimental support of Zaamo and Zalrsc
`A` extension has been split into two parts: Zaamo (Atomic Memory
Operations) and Zalrsc (Load-Reserved/Store-Conditional). See also
https://github.com/riscv/riscv-zaamo-zalrsc.

This patch adds the MC support.

Reviewers: dtcxzyw, topperc, kito-cheng

Reviewed By: topperc

Pull Request: https://github.com/llvm/llvm-project/pull/78970
2024-01-25 17:03:25 +08:00
Andy Kaylor
bb65f5a5d9
Move raw_string_ostream back to raw_ostream.cpp (#79224)
The implementation of raw_string_ostream::write_impl() was moved to
raw_socket_stream.cpp when the raw_socket_ostream support was separated.
This patch moves it back to facilitate disabling socket support in
downstream projects.
2024-01-24 11:20:23 -08:00
Jan Svoboda
6c1dbd5359
[clang] NFC: Remove {File,Directory}Entry::getName() (#74910)
The files and directories that Clang accesses are uniqued by their
inode. For each inode `FileManager` will create exactly one `FileEntry`
or `DirectoryEntry` object, which makes answering the question _"Are
these two files/directories the same?"_ a simple pointer equality check.

However, since the same inode can be accessed through multiple different
paths, asking the `FileEntry` or `DirectoryEntry` object _"What is your
name?"_ doesn't have clear semantics. In c0ff9908 we started reporting
the most recent name used to access the entry, which turned out to be
necessary for Clang modules. However, the long-term solution has always
been to explicitly track the as-requested name. This has been
implemented in 4dc5573a as `FileEntryRef` and `DirectoryEntryRef`.

The `DirectoryEntry::getName()` interface has been deprecated since the
Clang 17 release and `FileEntry::getName()` since Clang 18. We have
replaced uses of these deprecated APIs in `main` with
`DirectoryEntryRef::getName()` and `FileEntryRef::getName()`
respectively.

This makes it possible to remove `{File,Directory}Entry::getName()` for
good along with the `FileManager` code that implements them.
2024-01-24 08:41:14 -08:00
Rainer Orth
182ab1c703
[Support] Adjust .note.GNU-stack guard in Support/BLAKE3/blake3_*_x86-64_unix.S (#76229)
When using GNU ld 2.41 on FreeBSD 14.0/amd64, there are linker warnings
like
```
/vol/gcc/bin/gld-2.41: warning: blake3_avx512_x86-64_unix.S.o: missing .note.GNU-stack section implies executable stack
/vol/gcc/bin/gld-2.41: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
```
This can be fixed by adjusting the guard of the `.note.GNU-stack`
sections in `blake3_*_x86-64_unix.S` to match `llvm/lib/MC/MCAsmInfoELF.cpp:MCAsmInfoELF::getNonexecutableStackSection` which emits the section on all ELF targets
but Solaris.

Tested on `amd64-pc-freebsd14.0`.
2024-01-24 14:33:45 +01:00
Martin Storsjö
7ec078ed4b
[Support] Avoid a VirtualBox shared folders mmap bug (#78597)
In acd8791c2619f2afc0347c1bff073b32fbffb5d6, a call to FlushFileBuffers
was added to work around a rare kernel bug. In
3b9b4d2156673edda50584086fbfb0d66460b4d2, the scope of that workaround
was limited, for performance reasons, as the flushes are quite
expensive.

On VirtualBox shared folders, closing a memory mapping that has been
written to, also needs to be explicitly flushed, if renaming the output
file before it is closed. Contrary to the kernel bug, this always
happens on such mounts. In these cases, the output ends up as a file of
the right size, but the contents are all zeros.

The sequence to trigger the issue on the VirtualBox Shared Folders is
this, summarized:

    file = CreateFile()
    mapping = CreateFileMapping(file)
    mem = MapViewOfFile()
    CloseHandle(mapping)
    write(mem)
    UnmapViewOfFile(mem)
    SetFileInformationByHandle(file, FileRenameInfo)
    CloseHandle(file)

With this sequence, the output file always ends up with all zeros. See
https://github.com/mstorsjo/llvm-mingw/issues/393 for a full
reproduction example.

To avoid this issue, call FlushFileBuffers() when the file may reside on
a VitualBox shared folder. As the flushes are expensive, only do them
when the output isn't on a local file system.

The issue with VirtualBox shared folders could also be fixed by calling
FlushViewOfFile before UnmapViewOfFile, and doing that could be slightly
less expensive than FlushFileBuffers.

Empirically, the difference between the two is very small though, and as
it's not easy to verify whether switching FlushFileBuffers to
FlushViewOfFile helps with the rare kernel bug, keep using
FlushFileBuffers for both cases, for code simplicity.

This fixes downstream bug
https://github.com/mstorsjo/llvm-mingw/issues/393.
2024-01-23 13:39:48 +02:00
Andrei Golubev
5fb39efe68
[LLVM][ADT] Explicitly convert size_t values to SmallVector's size type (#77939)
Multiple places rely on implicit conversion when assigning 'size_t'
values to the member fields (size or capacity) of SmallVector.

Depending on the platform / compiler configuration, this may result in
narrowing conversion warnings (especially given that the size type of
SmallVector's member fields is determined based on type T - in
SmallVector<T>). To avoid the problem altogether, make the conversions
explicit.

Co-authored-by: Orest Chura <orest.chura@intel.com>
2024-01-22 00:39:11 -08:00
spupyrev
30aa9fb4c1 Revert "[InstrProf] Adding utility weights to BalancedPartitioning (#72717)"
This reverts commit 5954b9dca21bb0c69b9e991b2ddb84c8b05ecba3
due to broken Windows build
2024-01-19 15:13:47 -08:00
spupyrev
5954b9dca2
[InstrProf] Adding utility weights to BalancedPartitioning (#72717)
Adding weights to utility nodes in BP so that we can give more
importance to
certain utilities. This is useful when we optimize several objectives
jointly.
2024-01-19 13:36:59 -08:00
Min-Yih Hsu
5330daad41
[RISCV] Add support for Smepmp 1.0 (#78489)
Smepmp is a supervisor extension that prevents privileged processes from
accessing unprivileged program and data.

Spec: https://github.com/riscv/riscv-tee/blob/main/Smepmp/Smepmp.pdf
2024-01-19 11:09:35 -08:00
Luke Lau
8649328060
[RISCV] Add support for new unprivileged extensions defined in profiles spec (#77458)
This adds minimal support for 7 new unprivileged extensions that were
defined as a part of
the RISC-V Profiles specification here:

https://github.com/riscv/riscv-profiles/blob/main/profiles.adoc#7-new-isa-extensions

* Ziccif: Main memory supports instruction fetch with atomicity
requirement
* Ziccrse: Main memory supports forward progress on LR/SC sequences
* Ziccamoa: Main memory supports all atomics in A
* Zicclsm: Main memory supports misaligned loads/stores
* Za64rs: Reservation set size of 64 bytes
* Za128rs: Reservation set size of 128 bytes
* Zic64b: Cache block size isf 64 bytes

As stated in the specification, these extensions don't add any new
features but
describe existing features. So this patch only adds parsing and
subtarget
features.
2024-01-19 06:57:06 +07:00
Matheus Izvekov
361016f680
[Path] Fix off-by-one in finding filename for win style paths (#78055)
This fixes a crash where `path::parent_path` causes an invalid access on
a string upon receiving a path that consists of a single colon.

On Windows machine, with runtime checks enabled build, upon `clang -I:
test.cc` produces:
```
Assertion failed: Index < Length && "Invalid index!", file llvm\include\llvm/ADT/StringRef.h, line 232
...
 #6 0x00007ff7816201eb `anonymous namespace'::parent_path_end llvm\lib\Support\Path.cpp:144:0
 #7 0x00007ff781620135 llvm::sys::path::parent_path(class llvm::StringRef, enum llvm::sys::path::Style) llvm\lib\Support\Path.cpp:470:0
```

Ideally, we can look for the last colon starting from the last
character, but we can instead start from second to last, and handle
empty paths by abusing `0 - 1 == npos`.
2024-01-18 08:03:03 +01:00
Kazu Hirata
7e6482b3d8 [Support] Use SmallString::operator std::string (NFC) 2024-01-17 20:22:58 -08:00
cor3ntin
03e43cf1c7
[Clang] Update Unicode version to 15.1 (#77147)
This update all of our Unicode tables to Unicode 15.1. This is a minor
version so only a relatively small numbers of characters are added,
mainly ideographs

https://www.unicode.org/versions/Unicode15.1.0/#Appendices_nb
2024-01-17 22:55:58 +01:00
Fangrui Song
0c6dc80531
BalancedPartitioning: minor updates (#77568)
When LargestTraceSize is a power of two, createBPFunctionNodes does not
allocate a group ID for Trace[LargestTraceSize-1] (as N is off by 1).
Fix
this and change floor+log2 to Log2_64.

BalancedPartitioning::bisect can use unstable sort because `Nodes`
contains distinct `InputOrderIndex`s.

BalancedPartitioning::runIterations: use one DenseMap and simplify the
node renumbering code.
2024-01-17 10:46:34 -08:00
Craig Topper
7fe5269b54
[RISCV] Bump Zfbfmin, Zvfbfmin, and Zvfbfwma to 1.0. (#78021) 2024-01-16 08:42:21 -08:00
Wang Pengcheng
3ac9fe69f7
[RISCV] CodeGen of RVE and ilp32e/lp64e ABIs (#76777)
This commit includes the necessary changes to clang and LLVM to support
codegen of `RVE` and the `ilp32e`/`lp64e` ABIs.

The differences between `RVE` and `RVI` are:
* `RVE` reduces the integer register count to 16(x0-x16).
* The ABI should be `ilp32e` for 32 bits and `lp64e` for 64 bits.

`RVE` can be combined with all current standard extensions.

The central changes in ilp32e/lp64e ABI, compared to ilp32/lp64 are:
* Only 6 integer argument registers (rather than 8).
* Only 2 callee-saved registers (rather than 12).
* A Stack Alignment of 32bits (rather than 128bits).
* ilp32e isn't compatible with D ISA extension.

If `ilp32e` or `lp64` is used with an ISA that has any of the registers
x16-x31 and f0-f31, then these registers are considered temporaries.

To be compatible with the implementation of ilp32e in GCC, we don't use
aligned registers to pass variadic arguments and set stack alignment\
to 4-bytes for types with length of 2*XLEN.

FastCC is also supported on RVE, while GHC isn't since there is only one
avaiable register.

Differential Revision: https://reviews.llvm.org/D70401
2024-01-16 20:44:30 +08:00
Haydn Trigg
74cb2879ba
[Support] Windows Filesystem fs::status Conditionally Call GetFileAttributes (#78118)
Rather than conditionally using the output from GetFileAttributesW move
the branch to avoid calling GetFileAttributesW entirely if not required.
This avoids hitting IO an extra time for a small performance
improvement.
2024-01-15 08:08:11 -05:00
Brad Smith
2e0a105761
[CMake] Fix building on Haiku and Solaris after c0d5d36dda04cdd409aabc015da0beb810842fcd (#78084)
Haiku and Solaris need some additional libraries after the commit
c0d5d36dda04cdd409aabc015da0beb810842fcd

Otherwise fails to link a whole bunch of the tools and other binaries
with undefined symbols with accept() and connect().

I did a static and dynamic build on illumos and a dynamic build on
Haiku.

```
-DLLVM_ENABLE_PROJECTS='clang;clang-tools-extra;lld;mlir'
```
and on illumos
```
-DLLVM_ENABLE_RUNTIMES='openmp'
```
2024-01-14 20:23:22 -05:00
Kazu Hirata
b5d6ea4d8b [Support] Use StringRef::consume_front (NFC) 2024-01-13 18:18:49 -08:00
Kazu Hirata
1df4fb9881 [Support] Use StringRef::ltrim (NFC) 2024-01-12 18:39:53 -08:00
Igor Kudrin
9f8c818141
[CommandLine][NFCI] Do not add 'All' to 'RegisteredSubCommands' (#77722)
After #75679, it is no longer necessary to add the `All` pseudo
subcommand to the list of registered subcommands. The change causes the
list to contain only real subcommands, i.e. an unnamed top-level
subcommand and named ones. This simplifies the code a bit by removing
some checks for this special case.

This is a fixed version of #77041, where options of the 'All' subcommand
were not added to subcommands defined after them.
2024-01-13 02:19:42 +07:00
Kazu Hirata
5e9da33b87 [llvm] Use StringRef::consume_front_insensitive (NFC) 2024-01-11 22:48:20 -08:00
Alexandre Ganea
3c6f47d6b8
[llvm-driver] Fix usage of InitLLVM on Windows (#76306)
Previously, some tools such as `clang` or `lld` which require strict
order for certain command-line options, such as `clang -cc1` or `lld
-flavor`, would not longer work on Windows, when these tools were linked
as part of `llvm-driver`. This was caused by `InitLLVM` which was part
of the `*_main()` function of these tools, which in turn calls
`windows::GetCommandLineArguments`. That function completly replaces
argc/argv by new UTF-8 contents, so any ajustements to argc/argv made by
`llvm-driver` prior to calling these tools was reset.

`InitLLVM` is now called by the `llvm-driver`. Any tool that
participates in (or is part of) the `llvm-driver` doesn't call
`InitLLVM` anymore.
2024-01-11 19:08:28 -05:00