Commit Graph

269 Commits

Author SHA1 Message Date
Chris Lattner e48c31ce33 implement PR8576, deleting dead stores with intervening may-alias stores.
llvm-svn: 119927
2010-11-21 07:34:32 +00:00
Dan Gohman 65316d6749 Add helper functions for computing the Location of load, store,
and vaarg instructions.

llvm-svn: 118845
2010-11-11 21:50:19 +00:00
Dan Gohman c87c843db7 It's not necessary to clear out the Size and TBAATag at each of
these points.

llvm-svn: 118752
2010-11-11 00:42:22 +00:00
Dan Gohman 8bf3d832e5 Set NonLocalDepInfo's Size field to UnknownSize when invalidating
it, so that it doesn't appear to be a known size.

llvm-svn: 118748
2010-11-11 00:20:27 +00:00
Dan Gohman 6791936848 When clearing a non-local pointer dependency cache entry, clear
the reverse map too. This fixes seflhost build errors.

llvm-svn: 118729
2010-11-10 22:35:02 +00:00
Dan Gohman 1d760ce8b3 Factor out the code for computing an AliasAnalysis::Location
for a given instruction into a helper function.

llvm-svn: 118723
2010-11-10 21:51:35 +00:00
Dan Gohman 2e8ca44b81 Fully invalidate cached results when a prior query's size or
type is insufficient for, or incompatible with, the current query.

llvm-svn: 118721
2010-11-10 21:45:11 +00:00
Dan Gohman 0a6021a54d Enhance GVN to do more precise alias queries for non-local memory
references. For example, this allows gvn to eliminate the load in
this example:

  void foo(int n, int* p, int *q) {
    p[0] = 0;
    p[1] = 1;
    if (n) {
      *q = p[0];
    }
  }

llvm-svn: 118714
2010-11-10 20:37:15 +00:00
Dan Gohman 15a43965ac Teach memdep to use pointsToConstantMemory to determine that loads
from constant memory don't alias any stores.

llvm-svn: 117636
2010-10-29 01:14:04 +00:00
Owen Anderson 6c18d1aac0 Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which
must be called in the pass's constructor.  This function uses static dependency declarations to recursively initialize
the pass's dependencies.

Clients that only create passes through the createFooPass() APIs will require no changes.  Clients that want to use the
CommandLine options for passes will need to manually call the appropriate initialization functions in PassInitialization.h
before parsing commandline arguments.

I have tested this with all standard configurations of clang and llvm-gcc on Darwin.  It is possible that there are problems
with the static dependencies that will only be visible with non-standard options.  If you encounter any crash in pass
registration/creation, please send the testcase to me directly.

llvm-svn: 116820
2010-10-19 17:21:58 +00:00
Owen Anderson 8ac477ffb5 Begin adding static dependence information to passes, which will allow us to
perform initialization without static constructors AND without explicit initialization
by the client.  For the moment, passes are required to initialize both their
(potential) dependencies and any passes they preserve.  I hope to be able to relax
the latter requirement in the future.

llvm-svn: 116334
2010-10-12 19:48:12 +00:00
Owen Anderson df7a4f2515 Now with fewer extraneous semicolons!
llvm-svn: 115996
2010-10-07 22:25:06 +00:00
Dan Gohman 2348393cf5 Teach memdep about TBAA tags.
llvm-svn: 114588
2010-09-22 21:41:02 +00:00
Chris Lattner a58edd1df3 cleanup some of the lifetime/invariant marker stuff, add a big fixme.
llvm-svn: 113144
2010-09-06 03:58:04 +00:00
Chris Lattner e34c835bde speed up -gvn 3.4% on the testcase in PR7023
llvm-svn: 113135
2010-09-06 01:26:29 +00:00
Owen Anderson a7aed18624 Reapply r110396, with fixes to appease the Linux buildbot gods.
llvm-svn: 110460
2010-08-06 18:33:48 +00:00
Owen Anderson bda59bd247 Revert r110396 to fix buildbots.
llvm-svn: 110410
2010-08-06 00:23:35 +00:00
Owen Anderson 755aceb5d0 Don't use PassInfo* as a type identifier for passes. Instead, use the address of the static
ID member as the sole unique type identifier.  Clean up APIs related to this change.

llvm-svn: 110396
2010-08-05 23:42:04 +00:00
Dan Gohman 26ef7c7ab7 Fix memdep's code for reasoning about dependences between two calls. A Ref
response from getModRefInfo is not useful here. Instead, check for identical
calls only in the NoModRef case.

Reapply r110270, and strengthen it to compensate for the memdep changes.
When both calls are readonly, there is no dependence between them.

llvm-svn: 110382
2010-08-05 22:09:15 +00:00
Dan Gohman da7182e116 Add a convenient form of AliasAnalysis::alias for the case where the sizes
are unknown.

llvm-svn: 110090
2010-08-03 00:56:30 +00:00
Gabor Greif 0630a71742 reintroduce original (asserting) semantics of CallSite(Instruction *II)
add instead a CallSite(Value* V) constructor that is consistent with ImmutableCallSize
and use that one in client code

llvm-svn: 109553
2010-07-27 22:53:28 +00:00
Gabor Greif ef1ca24b91 recommit simplification (originally r109504, backed out in r109508) now that problem in CallSiteBase is fixed
llvm-svn: 109547
2010-07-27 22:02:00 +00:00
Gabor Greif ed1d92cb9a back out r109504, breaks the bots
llvm-svn: 109508
2010-07-27 15:18:11 +00:00
Gabor Greif 195a609c37 simplify
llvm-svn: 109504
2010-07-27 14:38:38 +00:00
Owen Anderson a57b97e7e7 Fix batch of converting RegisterPass<> to INTIALIZE_PASS().
llvm-svn: 109045
2010-07-21 22:09:45 +00:00
Gabor Greif 253c6bf366 use the new isFreeCall API and ArgOperand accessors
llvm-svn: 106692
2010-06-23 22:48:06 +00:00
Dan Gohman d2d1ae105d Use pre-increment instead of post-increment when the result is not used.
llvm-svn: 106542
2010-06-22 15:08:57 +00:00
Eric Christopher 7258dcd77f Revert 101465, it broke internal OpenGL testing.
Probably the best way to know that all getOperand() calls have been handled
is to replace that API instead of updating.

llvm-svn: 101579
2010-04-16 23:37:20 +00:00
Gabor Greif f375520f7b reapply r101434
with a fix for self-hosting

rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary

llvm-svn: 101465
2010-04-16 15:33:14 +00:00
Gabor Greif 403e9694f9 back out r101423 and r101397, they break llvm-gcc self-host on darwin10
llvm-svn: 101434
2010-04-16 01:16:20 +00:00
Gabor Greif 33ae80bff7 reapply r101364, which has been backed out in r101368
with a fix

rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary

llvm-svn: 101397
2010-04-15 20:51:13 +00:00
Gabor Greif 9fd00c7d25 back out r101364, as it trips the linux nightlybot on some clang C++ tests
llvm-svn: 101368
2010-04-15 12:46:56 +00:00
Gabor Greif aafd209632 rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary

llvm-svn: 101364
2010-04-15 10:49:53 +00:00
Daniel Dunbar 693ea89214 Reapply r97010, the speculative revert failed.
llvm-svn: 97036
2010-02-24 08:48:04 +00:00
Daniel Dunbar 0a2031e5b6 Speculatively revert r97010, "Add an argument to PHITranslateValue to specify
the DominatorTree. ...", in hopes of restoring poor old PPC bootstrap.

llvm-svn: 97027
2010-02-24 06:55:22 +00:00
Bob Wilson 66e58ac742 Add an argument to PHITranslateValue to specify the DominatorTree. If this
argument is non-null, pass it along to PHITranslateSubExpr so that it can
prefer using existing values that dominate the PredBB, instead of just
blindly picking the first equivalent value that it finds on a uselist.
Also when the DominatorTree is specified, have PHITranslateValue filter
out any result that does not dominate the PredBB.  This is basically just
refactoring the check that used to be in GetAvailablePHITranslatedSubExpr
and also in GVN.

Despite my initial expectations, this change does not affect the results
of GVN for any testcases that I could find, but it should help compile time.
Before this change, if PHITranslateSubExpr picked a value that does not
dominate, PHITranslateWithInsertion would then insert a new value, which GVN
would later determine to be redundant and would replace.  By picking a good
value to begin with, we save GVN the extra work of inserting and then
replacing a new value.

llvm-svn: 97010
2010-02-24 01:39:00 +00:00
Bob Wilson 92cdb6eec5 Split critical edges as needed for load PRE.
llvm-svn: 96378
2010-02-16 19:51:59 +00:00
Duncan Sands 19d0b47b1f There are two ways of checking for a given type, for example isa<PointerType>(T)
and T->isPointerTy().  Convert most instances of the first form to the second form.
Requested by Chris.

llvm-svn: 96344
2010-02-16 11:11:14 +00:00
Chris Lattner 9b7d99eb76 The phi translated pointer can be computed when returning a partially cached result
instead of stored.  This reduces memdep memory usage, and also eliminates a bunch of
weakvh's.  This speeds up gvn on gcc.c-torture/20001226-1.c from 23.9s to 8.45s (2.8x)
on a different machine than earlier.

llvm-svn: 91885
2009-12-22 04:25:02 +00:00
Chris Lattner 2ee6787c1b avoid calling extractMallocCall when it's obvious we don't have
a call.  This speeds up memdep ~1.5%

llvm-svn: 91869
2009-12-22 01:00:32 +00:00
Chris Lattner 25bf6f8946 fix an overly conservative caching issue that caused memdep to
cache a pointer as being unavailable due to phi trans in the
wrong place.  This would cause later queries to fail even when
they didn't involve phi trans.

llvm-svn: 91787
2009-12-19 21:29:22 +00:00
Chris Lattner eea0f58393 enhance NonLocalDepEntry to keep the per-block phi translated address
of the query.

llvm-svn: 90958
2009-12-09 07:31:04 +00:00
Chris Lattner 0c31547168 change NonLocalDepEntry from being a typedef for an std::pair to be its
own small class.  No functionality change.

llvm-svn: 90956
2009-12-09 07:08:01 +00:00
Chris Lattner 972e6d8d00 Switch GVN and memdep to use PHITransAddr, which correctly handles
phi translation of complex expressions like &A[i+1].  This has the
following benefits:

1. The phi translation logic is all contained in its own class with
   a strong interface and verification that it is self consistent.

2. The logic is more correct than before.  Previously, if intermediate
   expressions got PHI translated, we'd miss the update and scan for
   the wrong pointers in predecessor blocks.  @phi_trans2 is a testcase
   for this.

3. We have a lot less code in memdep.

We can handle phi translation across blocks of things like @phi_trans3,
which is pretty insane :).

This patch should fix the miscompiles of 255.vortex, and I tested it 
with a bootstrap of llvm-gcc, llvm-test and dejagnu of course.

llvm-svn: 90926
2009-12-09 01:59:31 +00:00
Nick Lewycky e91765fdbb Fix indentation in switch statement.
llvm-svn: 90650
2009-12-05 06:37:24 +00:00
Benjamin Kramer eee88bc5d2 Silence compiler warnings.
llvm-svn: 90319
2009-12-02 15:33:44 +00:00
Owen Anderson b9878ee6b6 Cleanup/remove some parts of the lifetime region handling code in memdep and GVN,
per Chris' comments.  Adjust testcases to match.

llvm-svn: 90304
2009-12-02 07:35:19 +00:00
Chris Lattner e914c0eaa0 rename some variables.
llvm-svn: 90258
2009-12-01 21:16:01 +00:00
Chris Lattner 506b858c45 tidy
llvm-svn: 90257
2009-12-01 21:15:15 +00:00
Chris Lattner 9c2053b242 fix 255.vortex again, third time's the charm.
llvm-svn: 90217
2009-12-01 07:33:32 +00:00
Nick Lewycky 2d32947099 Revert r90107, fixing test/Transforms/GVN/2009-11-29-ReverseMap.ll and the
llvm-gcc build.

llvm-svn: 90113
2009-11-30 07:05:51 +00:00
Chris Lattner 4d252d20e8 reapply r90093 with an addition of keeping the forward
and reverse nonlocal memdep maps in synch, this should
fix 255.vortex.

llvm-svn: 90107
2009-11-30 02:26:29 +00:00
Chris Lattner 0311ade94c revert this patch for now, it causes failures of:
LLVM::Transforms/GVN/2009-02-17-LoadPRECrash.ll
    LLVM::Transforms/GVN/2009-06-17-InvalidPRE.ll

llvm-svn: 90096
2009-11-29 21:14:59 +00:00
Chris Lattner 52e7715b0b Fix a really nasty caching bug I introduced in memdep. An entry
was being added to the Result vector, but not being put in the
cache.  This means that if the cache was reused wholesale for a
later query that it would be missing this entry and we'd do an
incorrect load elimination.

Unfortunately, it's not really possible to write a useful 
testcase for this, but this unbreaks 255.vortex.

llvm-svn: 90093
2009-11-29 21:09:36 +00:00
Nick Lewycky 0a1f25b927 Detabify.
llvm-svn: 90085
2009-11-29 18:10:39 +00:00
Nick Lewycky 218a3393f4 Teach memdep to look for memory use intrinsics during dependency queries. Fixes
PR5574.

llvm-svn: 90045
2009-11-28 21:27:49 +00:00
Chris Lattner 44da5bd837 Enhance InsertPHITranslatedPointer to be able to return a list of newly
inserted instructions.  No functionality change until someone starts using it.

llvm-svn: 90039
2009-11-28 15:39:14 +00:00
Chris Lattner d5bd369a0f enable code to handle un-phi-translatable cases more aggressively:
if we don't have an address expression available in a predecessor,
then model this as the value being clobbered at the end of the pred
block instead of being modeled as a complete phi translation failure.
This is important for PRE of loads because we want to see that the
load is available in all but this predecessor, and complete phi
translation failure results in not getting any information about
predecessors.

This doesn't do anything until I renable code insertion since PRE
now sees that it is available in all but one predecessors, but can't
insert the addressing in the predecessor that is missing it to 
eliminate the redundancy.

llvm-svn: 90037
2009-11-28 14:54:10 +00:00
Chris Lattner 2be52e72ae Rework InsertPHITranslatedPointer to handle the recursive case, this
fixes PR5630 and sets the stage for the next phase of goodness (testcase
pending).

llvm-svn: 90019
2009-11-27 22:05:15 +00:00
Chris Lattner 4ee17e1482 recursively phi translate bitcast operands too, for consistency.
llvm-svn: 90016
2009-11-27 20:25:30 +00:00
Chris Lattner 2f0354ecf0 add support for recursive phi translation and phi
translation of add with immediate.  This allows us
to optimize this function:

void test(int N, double* G) {
  long j;
  G[1] = 1;
    for (j = 1; j < N - 1; j++)
        G[j+1] = G[j] + G[j+1];
}

to only do one load every iteration of the loop.

llvm-svn: 90013
2009-11-27 19:11:31 +00:00
Chris Lattner 6d294de548 add comment.
llvm-svn: 90002
2009-11-27 08:40:14 +00:00
Chris Lattner ac323297e0 reduce nesting, no functionality change.
llvm-svn: 90001
2009-11-27 08:37:22 +00:00
Chris Lattner 25be93dfed teach GVN's load PRE to insert computations of the address in predecessors
where it is not available.  It's unclear how to get this inserted 
computation into GVN's scalar availability sets, Owen, help? :)

llvm-svn: 89997
2009-11-27 08:25:10 +00:00
Chris Lattner a9a76ccf56 Fix phi translation in load PRE to agree with the phi
translation done by memdep, and reenable gep translation 
again.

llvm-svn: 89992
2009-11-27 06:31:14 +00:00
Chris Lattner b018bda665 redisable this, my bootstrap worked because it wasn't an optimized build, whoops.
llvm-svn: 89991
2009-11-27 05:53:01 +00:00
Chris Lattner fb8a718fc3 try again.
llvm-svn: 89990
2009-11-27 05:19:56 +00:00
Chris Lattner 14444f5c1a this is causing buildbot failures, disable for now.
llvm-svn: 89985
2009-11-27 01:52:22 +00:00
Chris Lattner 5030c6ab21 teach phi translation of GEPs to simplify geps like 'gep x, 0'.
This allows us to compile the example from PR5313 into:

LBB1_2:                                                     ## %bb
	incl	%ecx
	movb	%al, (%rsi)
	movslq	%ecx, %rax
	movb	(%rdi,%rax), %al
	testb	%al, %al
	jne	LBB1_2

instead of:

LBB1_2:                                                     ## %bb
	movslq	%eax, %rcx
	incl	%eax
	movb	(%rdi,%rcx), %cl
	movb	%cl, (%rsi)
	movslq	%eax, %rcx
	cmpb	$0, (%rdi,%rcx)
	jne	LBB1_2

llvm-svn: 89981
2009-11-27 00:34:38 +00:00
Chris Lattner 4c88e814b8 teach memdep to do trivial PHI translation of GEPs. More to
come.

llvm-svn: 89979
2009-11-27 00:07:37 +00:00
Chris Lattner 9bd2136ca3 Teach memdep to phi translate bitcasts. This allows us to compile
the example in GCC PR16799 to:

LBB1_2:                                                     ## %bb1
	movl	%eax, %eax
	subq	%rax, %rdi
	movq	%rdi, (%rcx)
	movl	(%rdi), %eax
	testl	%eax, %eax
	je	LBB1_2

instead of:

LBB1_2:                                                     ## %bb1
	movl	(%rdi), %ecx
	subq	%rcx, %rdi
	movq	%rdi, (%rax)
	cmpl	$0, (%rdi)
	je	LBB1_2

llvm-svn: 89978
2009-11-26 23:41:07 +00:00
Chris Lattner c49f5ac7d8 factor some code out into some helper functions.
llvm-svn: 89975
2009-11-26 23:18:49 +00:00
Nick Lewycky 663e0a06b0 Remove dead code. While there, also turn a few 'T* ' into 'T *' to match the
rest of the file.

llvm-svn: 89577
2009-11-22 02:38:11 +00:00
Owen Anderson 2b2bd28973 Treat lifetime begin/end markers as allocations/frees respectively for the
purposes for GVN/DSE.

llvm-svn: 85383
2009-10-28 07:05:35 +00:00
Owen Anderson fc16e5a98f Be more careful about invariance reasoning on "store" queries. Stores still need
to depend on Ref and ModRef calls within the invariant region.

llvm-svn: 85380
2009-10-28 06:30:52 +00:00
Owen Anderson d0e86d57c1 Add trivial support for the invariance intrinsics to memdep. This logic is
purely local for now.

llvm-svn: 85378
2009-10-28 06:18:42 +00:00
Victor Hernandez f390e04a47 Rename MallocFreeHelper as MemoryBuiltins
llvm-svn: 85286
2009-10-27 20:05:49 +00:00
Victor Hernandez 762195bd01 Rename MallocHelper as MallocFreeHelper, since it now also identifies calls to free()
llvm-svn: 85181
2009-10-26 23:58:56 +00:00
Victor Hernandez de5ad42aa1 Remove FreeInst.
Remove LowerAllocations pass.
Update some more passes to treate free calls just like they were treating FreeInst.

llvm-svn: 85176
2009-10-26 23:43:48 +00:00
Victor Hernandez e297149e26 Auto-upgrade free instructions to calls to the builtin free function.
Update all analysis passes and transforms to treat free calls just like FreeInst.
Remove RaiseAllocations and all its tests since FreeInst no longer needs to be raised.

llvm-svn: 84987
2009-10-24 04:23:03 +00:00
Victor Hernandez 8acf2956b8 Remove AllocationInst. Since MallocInst went away, AllocaInst is the only subclass of AllocationInst, so it no longer is necessary.
llvm-svn: 84969
2009-10-23 21:09:37 +00:00
Victor Hernandez 70e8505eb1 Memory dependence analysis was incorrectly stopping to scan for stores to a pointer at bitcast uses of a malloc call.
It should continue scanning until the malloc call, and this patch fixes that.

llvm-svn: 83931
2009-10-13 01:42:53 +00:00
Chris Lattner 7e6d56ebc5 Revert r82404, it is causing a bootstrap miscompile. This is very very
scary, as it indicates a lurking bug. yay.

llvm-svn: 82411
2009-09-20 22:44:26 +00:00
Chris Lattner eea16a168a improve memdep to eliminate bitcasts (and aliases, and noop geps)
early for the stated reasons: this allows it to find more 
equivalences and depend less on code layout.

llvm-svn: 82404
2009-09-20 21:00:18 +00:00
Victor Hernandez 537d8d99be Enhance analysis passes so that they apply the same analysis to malloc calls as to MallocInst.
Reviewed by Eli Friedman.

llvm-svn: 82281
2009-09-18 21:34:51 +00:00
Dan Gohman 1ee6057b21 Make TargetData optional in MemoryDependenceAnalysis.
llvm-svn: 77727
2009-07-31 20:53:12 +00:00
Dan Gohman f3ee7eaac3 Remove an unnecessary header.
llvm-svn: 77725
2009-07-31 20:47:45 +00:00
Chris Lattner 370aadabfc factor the 'optimized sort' code out into a static helper function
and use it from one more place.  Patch by Jakub Staszak!

llvm-svn: 75478
2009-07-13 17:20:05 +00:00
Chris Lattner 2f0c1c44d5 Move the re-sort of invalidated NonLocalPointerDeps cache earlier
so that all code paths get it.  PR4256 was about a case where the
phi translation loop would find all preds in the Visited cache, so
it could get by without re-sorting the NonLocalPointerDeps cache.
Fix this by resorting it earlier, there is no reason not to do this.

This patch inspired by Jakub Staszak's patch.

llvm-svn: 75476
2009-07-13 17:14:23 +00:00
Chris Lattner 02274a7171 make memdep use the getModRefInfo method for stores instead of the
low-level alias() method, allowing it to reason more aggressively
about pointers into constant memory.  PR4189

llvm-svn: 72403
2009-05-25 21:28:56 +00:00
Chris Lattner 8eda11bd9d now that you can put a PointerIntPair in a SmallPtrSet, remove some
hackish workarounds from memdep

llvm-svn: 67971
2009-03-29 00:24:04 +00:00
Dale Johannesen f61c8e81bd Debug intriniscs should be skipped when looking
for a dependency, not terminate the search.

llvm-svn: 66709
2009-03-11 21:13:01 +00:00
Owen Anderson f9a9cf96a1 Ignore debug intrinsics when computing dependences.
llvm-svn: 66399
2009-03-09 05:12:38 +00:00
Zhou Sheng c8e5085cd3 Remove this as dbginfo intrinsics has been defined as
IntrNoMem.

llvm-svn: 66256
2009-03-06 06:05:01 +00:00
Zhou Sheng abe4192442 Ignore the debug info intrinsics when looking for dependency through basic block.
llvm-svn: 66119
2009-03-05 01:45:43 +00:00
Chris Lattner 3f4591c89f fix two more cases where we could let the NLPDI cache get unsorted.
With this, sqlite3 now passes.

llvm-svn: 62839
2009-01-23 07:12:16 +00:00
Chris Lattner e3ea48c71e Unconditionally reset 'cache' to zero, even if we don't need to resort it.
This avoids using a dangling pointer.

Reset NumSortedEntries after restoring Cache to avoid extraneous sorts.
This fixes the reduced sqlite3 testcase, but apparently not the whole app.

llvm-svn: 62838
2009-01-23 06:48:41 +00:00
Chris Lattner 706d40e662 a minor tweak to my previous patch, handle the invalidation case
when there are multiple iterations of the loop.  This fixes PR3375.

llvm-svn: 62822
2009-01-23 00:27:03 +00:00
Chris Lattner f09619d533 Fix PR3358, a really nasty bug where recursive phi translated
analyses could be run without the caches properly sorted.  This
can fix all sorts of weirdness.  Many thanks to Bill for coming
up with the 'issorted' verification idea.

llvm-svn: 62757
2009-01-22 07:04:01 +00:00
Chris Lattner 8b4be37275 fix PR3217: fully cached queries need to be verified against the
visited set before they are used.  If used, their blocks need to be
added to the visited set so that subsequent queries don't use conflicting
pointer values in the cache result blocks.

llvm-svn: 61080
2008-12-16 07:10:09 +00:00