Commit Graph

144 Commits

Author SHA1 Message Date
Kazu Hirata 5cff5142a8 Use value instead of getValue (NFC) 2022-07-15 20:03:13 -07:00
Kazu Hirata e5f568a49f Use has_value instead of hasValue (NFC) 2022-07-13 01:58:03 -07:00
Kazu Hirata 3b7c3a654c Revert "Don't use Optional::hasValue (NFC)"
This reverts commit aa8feeefd3.
2022-06-25 11:56:50 -07:00
Kazu Hirata aa8feeefd3 Don't use Optional::hasValue (NFC) 2022-06-25 11:55:57 -07:00
Kazu Hirata ed8fceaa09 Don't use Optional::getValue (NFC) 2022-06-20 23:35:53 -07:00
Guillaume Chatelet 4296f91323 [NFC][Alignment] Simplify code in JSONExporter 2022-06-13 13:36:36 +00:00
Michael Kruse bd93df937a [Polly] Mark classes as final by default. NFC.
This make is obivious that a class was not intended to be derived from.

NPM analysis pass can unfortunately not marked as final because they are
derived from a llvm::Checker<T> template internally by the NPM.

Also normalize the use of classes/structs
 * NPM passes are structs
 * Legacy passes are classes
 * structs that have methods and are not a visitor pattern are classes
 * structs have public inheritance by default, remove "public" keyword
 * Use typedef'ed type instead of inline forward declaration
2022-05-17 12:05:39 -05:00
Michael Kruse 5c02808131 [polly] Introduce -polly-print-* passes to replace -analyze.
The `opt -analyze` option only works with the legacy pass manager and might be removed in the future, as explained in llvm.org/PR53733. This patch introduced -polly-print-* passes that print what the pass would print with the `-analyze` option and replaces all uses of `-analyze` in the regression tests.

There are two exceptions: `CodeGen\single_loop_param_less_equal.ll` and `CodeGen\loop_with_condition_nested.ll` use `-analyze on the `-loops` pass which is not part of Polly.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D120782
2022-03-14 10:27:15 -05:00
Riccardo Mori 44596fe6a9 [Polly][Isl] Use the function unsignedFromIslSize to manage a isl::size object. NFCI
This is part of an effort to reduce the differences between the custom C++ bindings used right now by polly in lib/External/isl/include/isl/isl-noxceptions.h and the official isl C++ interface.
In the official interface the type `isl::size` cannot be casted to an unsigned without previously having checked if it contains a valid value with the function `isl::size::is_error()`.
For this reason two helping functions have been added:
 - `IslAssert`: assert that no errors are present in debug builds and just disables the mandatory error check in non-debug builds
 - `unisgnedFromIslSIze`: cast the `isl::size` object to `unsigned`

Changes made:
 - Add the functions `IslAssert` and `unsignedFromIslSize`
 - Add the utility function `rangeIslSize()`
 - Retype `MaxDisjunctsInDomain` from `int` to `unsigned`
 - Retype `RunTimeChecksMaxAccessDisjuncts` from `int` to `unsigned`
 - Retype `MaxDimensionsInAccessRange` from `int` to `unsigned`
 - Replaced some usages of `isl_size` to `unsigned` since we aim not to use `isl_size` anymore
 - `isl-noexceptions.h` has been generated by e704f73c88

No functional change intended.

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D113101
2021-11-05 11:15:22 +01:00
Riccardo Mori d3fdbda6b0 [Polly][Isl] Move to the new-polly-generator branch version of isl-noexceptions.h. NFCI
This is part of an effort to reduce the differences between the custom C++ bindings used right now by polly in `lib/External/isl/include/isl/isl-noxceptions.h` and the official isl C++ interface.

With this commit we are moving from the `polly-generator` branch to the `new-polly-generator` branch that is more mantainable and is based on the official C++ interface `cpp-checked.h`.

Changes made:
 - There are now many sublcasses for `isl::ast_node` representing different isl types. Use `isl::ast_node_for`, `isl::ast_node_user`, `isl::ast_node_block` and `isl::ast_node_mark` where needed.
 - There are now many sublcasses for `isl::schedule_node` representing different isl types. Use `isl::schedule_node_mark`, `isl::schedule_node_extension`, `isl::schedule_node_band` and `isl::schedule_node_filter` where needed.
 - Replace the `isl::*::dump` with `dumpIslObj` since the isl dump method is not exposed in the C++ interface.
 - `isl::schedule_node::get_child` has been renamed to `isl::schedule_node::child`
 - `isl::pw_multi_aff::get_pw_aff` has been renamed to `isl::pw_multi_aff::at`
 - The constructor `isl::union_map(isl::union_pw_multi_aff)` has been replaced with the static method `isl::union_map::from()`
 - Replace usages of `isl::val::add_ui` with `isl::val::add`
 - `isl::union_set_list::alloc` is now a constructor
 - All the `isl_size` values are now wrapped inside the class `isl::size` use `isl::size::release` to get the internal `isl_size` value where needed.
 - `isl-noexceptions.h` has been generated by 73f5ed1f4d

No functional change intended.

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D107225
2021-08-16 15:53:26 +02:00
Riccardo Mori d5ee355f89 [Polly][Isl] Use isl::union_map::unite() instead of isl::union_map::add_map(). NFC
This is part of an effort to reduce the differences between the custom C++ bindings used right now by polly in `lib/External/isl/include/isl/isl-noxceptions.h` and the official isl C++ interface.

Changes made:
 - Use `isl::union_map::unite()` instead of `isl::union_map::add_map()`
 - `isl-noexceptions.h` has been generated by this 3f43ae29fa

Depends on D106059

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D106061
2021-07-19 12:11:00 +02:00
Riccardo Mori bad3ebbaae [Polly][Isl] Stop generating isl::union_{set,map} from isl::space. NFC
This is part of an effort to reduce the differences between the custom C++ bindings used right now by polly in `lib/External/isl/include/isl/isl-noxceptions.h` and the official isl C++ interface.

Changes made:
 - Stop generating `isl::union_set` and isl::union_map` from `isl::space` and instead generate them from `isl::ctx`
 - Disable clang-format on `isl-noexceptions.h`
 - Removed `isl::union_{set,map}` generator from `isl::space` from `isl-noexceptions.h`
 - `isl-noexceptions.h` has been generated by this 87c3413b6f

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D106059
2021-07-19 11:24:53 +02:00
patacca 7c7978a122 [Polly][Isl] Removing explicit operator bool() from isl C++ bindings. NFC.
This is part of an effort to reduce the differences between the custom C++ bindings used right now by polly in `lib/External/isl/include/isl/isl-noxceptions.h` and the official isl C++ interface.

Changes made:
 - Removing explicit operator bool() from all the classes in the isl C++ bindings.
 - Replace each call to operator bool() to method `is_null()`.
 - isl-noexceptions.h has been generated by this 27396daac5

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D103976
2021-06-11 14:44:24 +02:00
Abhina Sreeskantharajan 82b3e28e83 [SystemZ][z/OS][Windows] Add new OF_TextWithCRLF flag and use this flag instead of OF_Text
Problem:
On SystemZ we need to open text files in text mode. On Windows, files opened in text mode adds a CRLF '\r\n' which may not be desirable.

Solution:
This patch adds two new flags

  - OF_CRLF which indicates that CRLF translation is used.
  - OF_TextWithCRLF = OF_Text | OF_CRLF indicates that the file is text and uses CRLF translation.

Developers should now use either the OF_Text or OF_TextWithCRLF for text files and OF_None for binary files. If the developer doesn't want carriage returns on Windows, they should use OF_Text, if they do want carriage returns on Windows, they should use OF_TextWithCRLF.

So this is the behaviour per platform with my patch:

z/OS:
OF_None: open in binary mode
OF_Text : open in text mode
OF_TextWithCRLF: open in text mode

Windows:
OF_None: open file with no carriage return
OF_Text: open file with no carriage return
OF_TextWithCRLF: open file with carriage return

The Major change is in llvm/lib/Support/Windows/Path.inc to only set text mode if the OF_CRLF is set.
```
  if (Flags & OF_CRLF)
    CrtOpenFlags |= _O_TEXT;
```

These following files are the ones that still use OF_Text which I left unchanged. I modified all these except raw_ostream.cpp in recent patches so I know these were previously in Binary mode on Windows.
./llvm/lib/Support/raw_ostream.cpp
./llvm/lib/TableGen/Main.cpp
./llvm/tools/dsymutil/DwarfLinkerForBinary.cpp
./llvm/unittests/Support/Path.cpp
./clang/lib/StaticAnalyzer/Core/HTMLDiagnostics.cpp
./clang/lib/Frontend/CompilerInstance.cpp
./clang/lib/Driver/Driver.cpp
./clang/lib/Driver/ToolChains/Clang.cpp

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D99426
2021-04-06 07:23:31 -04:00
Michael Kruse d0240257cd [Polly] Silence mixed signed/unsigned comparison warnings. NFC.
ISL changed some return types from unsigned to
isl_size (typedef of int), which results in such warnings.
2020-02-10 19:03:08 -06:00
Eli Friedman 0257a9218b Fix polly build after StringRef change. 2020-01-28 19:44:20 -08:00
Fangrui Song d9b948b6eb Rename F_{None,Text,Append} to OF_{None,Text,Append}. NFC
F_{None,Text,Append} are kept for compatibility since r334221.

llvm-svn: 367800
2019-08-05 05:43:48 +00:00
Michael Kruse 031bb16556 Apply include-what-you-use #include removal suggestions. NFC.
This removes unused includes (and forward declarations) as
suggested by include-what-you-use. If a transitive include of a removed
include is required to compile a file, I added the required header (or
forward declaration if suggested by include-what-you-use).

This should reduce compilation time and reduce the number of iterative
recompilations when a header was changed.

llvm-svn: 357209
2019-03-28 20:19:49 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Michael Kruse 0e4e6e5e87 [DepInfo] Use isl++ in Dependences::isValidSchedule. NFC.
Also change StatementToIslMapTy to hold isl::map, because it is used as a
parameter.

llvm-svn: 339484
2018-08-10 22:33:27 +00:00
Michael Kruse ebca0f1609 [JSONExporter] Print instead of ignoring parser error.
Silence the warning

    warning: ignoring return value of function declared with 'warn_unused_result' attribute [-Wunused-result]

JSONExporter is a developer tool, there is no mechanism for error
handling. Print the parser error and abort with a fatal error.

llvm-svn: 338659
2018-08-02 00:11:14 +00:00
Michael Kruse 37b3c1775b [JSONExporter] Try to appease buildbot. NFC.
The compiler does not seem to able move a local variable in the
function's return statement.

llvm-svn: 338466
2018-08-01 00:48:01 +00:00
Michael Kruse 23655020a2 [JSONExporter] Replace bundled Jsoncpp with llvm/Support/JSON.h. NFC.
Differential Revision: https://reviews.llvm.org/D49950

llvm-svn: 338461
2018-08-01 00:15:16 +00:00
Michael Kruse 4485ae0890 [CodeGen] Allow undefined loads in statement instances outside context.
A check in assert-builds was meant to verify that a load provides a
value in all statement instances (i.e. its domain).  The domain is
commonly gist'ed within the parameter context to contain fewer
constraints.  However, statement instances outside the context are
no valid executions, hence the value provided can be undefined.

Refine the check for valid loads to only needed to be defined within
the SCoP context.

In addition, the JSONImporter had to be changed to allow importing
access relations that are broader than the current access relation,
but still defined over all statement instances.

This should fix the compiler crash in test-suite's oggenc of the
-polly-process-unprofitable buildbot.

llvm-svn: 329655
2018-04-10 01:20:51 +00:00
Philip Pfaffe 00fd43b327 Port ScopInfo to the isl cpp bindings
Summary:
Most changes are mechanical, but in one place I changed the program semantics
by fixing a likely bug:

In `Scop::hasFeasibleRuntimeContext()`, I'm now explicitely handling the
error-case. Before, when the call to `addNonEmptyDomainConstraints()`
returned a null set, this (probably) accidentally worked because
isl_bool_error converts to true. I'm checking for nullptr now.

Reviewers: grosser, Meinersbur, bollu

Reviewed By: Meinersbur

Subscribers: nemanjai, kbarton, pollydev, llvm-commits

Differential Revision: https://reviews.llvm.org/D39971

llvm-svn: 318632
2017-11-19 22:13:34 +00:00
Reid Kleckner 3fc649cb76 [Support] Rename tool_output_file to ToolOutputFile, NFC
This class isn't similar to anything from the STL, so it shouldn't use
the STL naming conventions.

llvm-svn: 314050
2017-09-23 01:03:17 +00:00
Michael Kruse a4f447c2a4 [PM] Properly require and preserve OptimizationRemarkEmitter. NFCI.
Properly require and preserve the OptimizationRemarkEmitter for use in
ScopPass. Previously one had to get the ORE from ScopDetection because
CodeGeneration did not mark it as preserved. It would need to be
recomputed which results in the legacy PM to throw away all previous
SCoP analysis.

This also changes the implementation of ScopPass::getAnalysisUsage to
not unconditionally preserve all passes, but only those needed to be
preserved by any SCoP pass (at least when using the legacy PM). This
allows invalidating DependenceInfo (and IslAstInfo) in case the pass
would cause them to change (e.g. OpTree, DeLICM, MaximalArrayExpansion)

JSONImporter should also invalidate the DependenceInfo. In this patch
it marks DependenceInfo as preserved anyway because some regression
tests depend on it.

Differential Revision: https://reviews.llvm.org/D37010

llvm-svn: 311888
2017-08-28 14:07:33 +00:00
Philip Pfaffe c3bcdc2f1a [JSON] Make the failure to parse a jscop file a hard error
Summary:
Before, if we fail to parse a jscop file, this will be reported as an
error and importing is aborted. However, this isn't actually strong
enough, since although the import is aborted, the scop has already been
modified and is very likely broken. Instead, make this a hard failure
and throw an LLVM error. This new behaviour requires small changes to
the tests for the legacy pass, namely using `not` to verify the error.
Further, fixed the jscop file for the
base_pointer_load_is_inst_inside_invariant_1 testcase.

Reviewed By: Meinersbur

Split out of D36578.

llvm-svn: 310599
2017-08-10 14:53:25 +00:00
Philip Pfaffe 47bf15c34f [JSON][PM] Port json import/export over to new pm
Summary:
I pulled out all functionality into static functions, and use those both
in the legacy passes and in the new ones.

Reviewers: grosser, Meinersbur, bollu

Reviewed By: Meinersbur

Subscribers: llvm-commits, pollydev

Differential Revision: https://reviews.llvm.org/D36578

llvm-svn: 310597
2017-08-10 14:45:09 +00:00
Tobias Grosser b65ccc4302 [ScopInfo] Translate Scop::getParamSpace to isl++ [NFC]
llvm-svn: 310224
2017-08-06 20:11:59 +00:00
Tobias Grosser 8ea1fc19b3 [ScopInfo] Translate Scop::getContext to isl++ [NFC]
llvm-svn: 310221
2017-08-06 19:52:38 +00:00
Tobias Grosser 6ad1640a1d [ScopInfo] Move ScopStmt::getSchedule to isl++
llvm-svn: 310215
2017-08-06 17:45:28 +00:00
Tobias Grosser dcf8d696ff Move ScopInfo::getDomain(), getDomainSpace(), getDomainId() to isl++
llvm-svn: 310209
2017-08-06 16:39:52 +00:00
Tobias Grosser 7b45af13ce Move setNewAccessRelation to isl++
llvm-svn: 309871
2017-08-02 19:27:25 +00:00
Tobias Grosser 206e9e3b3b Move ScopArrayInfo::getFromAccessFunction and getFromId to isl++
llvm-svn: 308892
2017-07-24 16:22:27 +00:00
Tobias Grosser 1515f6b937 Move MemoryAccess::NewAccessRelation to isl++
We also move related accessor functions

llvm-svn: 308840
2017-07-23 04:08:38 +00:00
Tobias Grosser 77eef90f50 Move ScopArrayInfo to isl++
This moves the full ScopArrayInfo class to isl++

llvm-svn: 308801
2017-07-21 23:07:56 +00:00
Michael Kruse cd4c977b8b [ScopInfo] Print instructions in dump().
Print a statement's instruction on dump() regardless of
-polly-print-instructions. dump() is supposed to be used in the debugger
only and never in regression tests. While debugging, get all the
information we have and we are not bound to break anything. For non-dump
purposes of print, forward the setting of -polly-print-instructions as
parameters.

Some calls to print() had to be changed because the
PollyPrintInstructions setting is only available in ScopInfo.cpp.
In ScheduleOptimizer.cpp, dump() was used in regression tests.
That's not what dump() is for.

The print parameter "PrintInstructions" will also be useful for an
explicit print SCoP pass in a future patch.

llvm-svn: 308746
2017-07-21 15:35:53 +00:00
Tobias Grosser 6a4c12fb33 Always export the latest memory access relations
This allows us to export the results from transformations such as DeLICM.

llvm-svn: 307641
2017-07-11 10:10:13 +00:00
Michael Kruse b738ffa845 Heap allocation for new arrays.
This patch aims to implement the option of allocating new arrays created
by polly on heap instead of stack. To enable this option, a key named
'allocation' must be written in the imported json file with the value
'heap'.

We need such a feature because in a next iteration, we will implement a
mechanism of maximal static expansion which will need a way to allocate
arrays on heap. Indeed, the expansion is very costly in terms of memory
and doing the allocation on stack is not worth considering.

The malloc and the free are added respectively at polly.start and
polly.exiting such that there is no use-after-free (for instance in case
of Scop in a loop) and such that all memory cells allocated with a
malloc are free'd when we don't need them anymore.

We also add :

- In the class ScopArrayInfo, we add a boolean as member called IsOnHeap
  which represents the fact that the array in allocated on heap or not.
- A new branch in the method allocateNewArrays in the ISLNodeBuilder for
  the case of heap allocation. allocateNewArrays now takes a BBPair
  containing polly.start and polly.exiting. allocateNewArrays takes this
  two blocks and add the malloc and free calls respectively to
  polly.start and polly.exiting.
- As IntPtrTy for the malloc call, we use the DataLayout one.

To do that, we have modified :

- createScopArrayInfo and getOrCreateScopArrayInfo such that it returns
  a non-const SAI, in order to be able to call setIsOnHeap in the
  JSONImporter.
- executeScopConditionnaly such that it return both start block and end
  block of the scop, because we need this two blocs to be able to add
  the malloc and the free calls at the right position.

Differential Revision: https://reviews.llvm.org/D33688

llvm-svn: 306540
2017-06-28 13:02:43 +00:00
Andreas Simbuerger 6d08ec7233 [JSONImport] Check, if the size of an imported array is positive
llvm-svn: 306479
2017-06-27 22:30:44 +00:00
Michael Kruse a6d48f59a1 Fix a lot of typos. NFC.
llvm-svn: 304974
2017-06-08 12:06:15 +00:00
Michael Kruse 281f414c9d [JScop] Emit error messages on error.
In importArrays instead of silently ignoring the file.

llvm-svn: 304817
2017-06-06 19:17:32 +00:00
Michael Kruse cb58bd6ccd [JSONImporter] misses checks whether the data it imports makes sense.
Without this patch, the JSONImporter did not verify if the data it loads
were correct or not  (Bug llvm.org/PR32543). I add some checks in the
JSONImporter class and some test cases.

Here are the checks (and test cases) I added :

JSONImporter::importContext
- The "context" key does not exist.
- The context was not parsed successfully by ISL.
- The isl_set has the wrong number of parameters.
- The isl_set is not a parameter set.

JSONImporter::importSchedule
- The "statements" key does not exist.
- There is not the right number of statement in the file.
- The "schedule" key does not exist.
- The schedule was not parsed successfully by ISL.

JSONImporter::importAccesses
- The "statements" key does not exist.
- There is not the right number of statement in the file.
- The "accesses" key does not exist.
- There is not the right number of memory accesses in the file.
- The "relation" key does not exist.
- The memory access was not parsed successfully by ISL.

JSONImporter::areArraysEqual
- The "type" key does not exist.
- The "sizes" key does not exist.
- The "name" key does not exist.

JSONImporter::importArrays
/!\ Do not check if there is an key name "arrays" because it is not
considered as an error.
All checks are already in place or implemented in
JSONImporter::areArraysEqual.

Contributed-by: Nicolas Bonfante <nicolas.bonfante@insa-lyon.fr>

Differential Revision: https://reviews.llvm.org/D32739

llvm-svn: 303759
2017-05-24 15:09:35 +00:00
Michael Kruse 706f79ab14 [CodeGen] Support partial write accesses.
Allow the BlockGenerator to generate memory writes that are not defined
over the complete statement domain, but only over a subset of it. It
generates a condition that evaluates to 1 if executing the subdomain,
and only then execute the access.

Only write accesses are supported. Read accesses would require a PHINode
which has a value if the access is not executed.

Partial write makes DeLICM able to apply mappings that are not defined
over the entire domain (for instance, a branch that leaves a loop with
a PHINode in its header; a MemoryKind::PHI write when leaving is never
read by its PHI read).

Differential Revision: https://reviews.llvm.org/D33255

llvm-svn: 303517
2017-05-21 22:46:57 +00:00
Roman Gareev b3224adfb6 Perform copying to created arrays according to the packing transformation
This is the fourth patch to apply the BLIS matmul optimization pattern on matmul
kernels (http://www.cs.utexas.edu/users/flame/pubs/TOMS-BLIS-Analytical.pdf).
BLIS implements gemm as three nested loops around a macro-kernel, plus two
packing routines. The macro-kernel is implemented in terms of two additional
loops around a micro-kernel. The micro-kernel is a loop around a rank-1
(i.e., outer product) update. In this change we perform copying to created
arrays, which is the last step to implement the packing transformation.

Reviewed-by: Tobias Grosser <tobias@grosser.es>

Differential Revision: https://reviews.llvm.org/D23260

llvm-svn: 281441
2016-09-14 06:26:09 +00:00
Roman Gareev f5aff70405 Store the size of the outermost dimension in case of newly created arrays that require memory allocation.
We do not need the size of the outermost dimension in most cases, but if we
allocate memory for newly created arrays, that size is needed.

Reviewed-by: Michael Kruse <llvm@meinersbur.de>

Differential Revision: https://reviews.llvm.org/D23991

llvm-svn: 281234
2016-09-12 17:08:31 +00:00
Tobias Grosser c80d6979bd Drop '@brief' from doxygen comments
LLVM's coding guideline suggests to not use @brief for one-sentence doxygen
comments to improve readability. Switch this once and for all to ensure people
do not copy @brief comments from other parts of Polly, when writing new code.

llvm-svn: 280468
2016-09-02 06:33:33 +00:00
Michael Kruse 2fa3519463 Allow mapping scalar MemoryAccesses to array elements.
Change the code around setNewAccessRelation to allow to use a an existing array
element for memory instead of an ad-hoc alloca. This facility will be used for
DeLICM/DeGVN to convert scalar dependencies into regular ones.

The changes necessary include:
- Make the code generator use the implicit locations instead of the alloca ones.
- A test case
- Make the JScop importer accept changes of scalar accesses for that test case.
- Adapt the MemoryAccess interface to the fact that the MemoryKind can change.
  They are named (get|is)OriginalXXX() to get the status of the memory access
  before any change by setNewAccessRelation() (some properties such as
  getIncoming() do not change even if the kind is changed and are still
  required). To get the modified properties, there is (get|is)LatestXXX(). The
  old accessors without Original|Latest become synonyms of the
  (get|is)OriginalXXX() to not make functional changes in unrelated code.

Differential Revision: https://reviews.llvm.org/D23962

llvm-svn: 280408
2016-09-01 19:53:31 +00:00
Michael Kruse d262feff80 Add space between access string and follow-up.
llvm-svn: 279826
2016-08-26 15:43:52 +00:00