Commit Graph

4877 Commits

Author SHA1 Message Date
Arnold Schwaighofer
1386692ef6 LoopVectorize: Hoist conditional loads if possible
InstCombine can be uncooperative to vectorization and sink loads into
conditional blocks. This prevents vectorization.

Undo this optimization if there are unconditional memory accesses to the same
addresses in the loop.

radar://13815763

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181860 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-15 01:44:30 +00:00
Manman Ren
5150270d07 GlobalOpt: fix an issue where CXAAtExitFn points to a deleted function.
CXAAtExitFn was set outside a loop and before optimizations where functions
can be deleted. This patch will set CXAAtExitFn inside the loop and after
optimizations.

Seg fault when running LTO because of accesses to a deleted function.
rdar://problem/13838828


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181838 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-14 21:52:44 +00:00
Arnold Schwaighofer
123f18bcb9 LoopVectorize: Handle loops with multiple forward inductions
We used to give up if we saw two integer inductions. After this patch, we base
further induction variables on the chosen one like we do in the reverse
induction and pointer induction case.

Fixes PR15720.

radar://13851975

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181746 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-14 00:21:18 +00:00
Michael Gottesman
acfb3584c5 [objc-arc-opts] In the presense of an alloca unconditionally remove RR pairs if and only if we are both KnownSafeBU/KnownSafeTD rather than just either or.
In the presense of a block being initialized, the frontend will emit the
objc_retain on the original pointer and the release on the pointer loaded from
the alloca. The optimizer will through the provenance analysis realize that the
two are related (albiet different), but since we only require KnownSafe in one
direction, will match the inner retain on the original pointer with the guard
release on the original pointer. This is fixed by ensuring that in the presense
of allocas we only unconditionally remove pointers if both our retain and our
release are KnownSafe (i.e. we are KnownSafe in both directions) since we must
deal with the possibility that the frontend will emit what (to the optimizer)
appears to be unbalanced retain/releases.

An example of the miscompile is:

  %A = alloca
  retain(%x)
  retain(%x) <--- Inner Retain
  store %x, %A
  %y = load %A
  ... DO STUFF ...
  release(%y)
  call void @use(%x)
  release(%x) <--- Guarding Release

getting optimized to:

  %A = alloca
  retain(%x)
  store %x, %A
  %y = load %A
  ... DO STUFF ...
  release(%y)
  call void @use(%x)

rdar://13750319

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181743 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-13 23:49:42 +00:00
Nadav Rotem
507b9242ed SLPVectorizer: Fix a bug in the code that generates extracts for values with multiple users.
The external user does not have to be in lane #0. We have to save the lane for each scalar so that we know which vector lane to extract.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181674 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-12 22:58:45 +00:00
David Majnemer
fa49d7d6e4 InstCombine: Flip the order of two urem transforms
There are two transforms in visitUrem that conflict with each other.

*) One, if a divisor is a power of two, subtracts one from the divisor
   and turns it into a bitwise-and.
*) The other unwraps both operands if they are surrounded by zext
   instructions.

Flipping the order allows the subtraction to go beneath the sign
extension.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181668 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-12 00:07:05 +00:00
Arnold Schwaighofer
9b5d70f076 LoopVectorize: Use the widest induction variable type
Use the widest induction type encountered for the cannonical induction variable.

We used to turn the following loop into an empty loop because we used i8 as
induction variable type and truncated 1024 to 0 as trip count.

int a[1024];
void fail() {
  int reverse_induction = 1023;
  unsigned char forward_induction = 0;
  while ((reverse_induction) >= 0) {
    forward_induction++;
    a[reverse_induction] = forward_induction;
    --reverse_induction;
  }
}

radar://13862901

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181667 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-11 23:04:28 +00:00
David Majnemer
a8ccefc0a3 InstCombine: Turn urem to bitwise-and more often
Use isKnownToBeAPowerOfTwo in visitUrem so that we may more aggressively
fold away urem instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181661 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-11 09:01:28 +00:00
Nadav Rotem
9bba9f6300 SLPVectorizer: Add support for trees with external users.
For example:
bar() {
  int a = A[i];
  int b = A[i+1];
  B[i] = a;
  B[i+1] = b;
  foo(a);  <--- a is used outside the vectorized expression.
}



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181648 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-10 22:59:33 +00:00
Nadav Rotem
ef3e423e23 Add an additional testcase for PR15882.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181646 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-10 22:55:44 +00:00
Benjamin Kramer
7159a307b9 InstCombine: Don't claim to be able to evaluate any shl in a zexted type.
The shift amount may be larger than the type leading to undefined behavior.
Limit the transform to constant shift amounts. While there update the bits to
clear in the result which may enable additional optimizations.

PR15959.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181604 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-10 16:26:37 +00:00
Benjamin Kramer
51dab6e394 InstCombine: Verify the type before transforming uitofp into select.
PR15952.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181586 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-10 09:16:52 +00:00
Rafael Espindola
95f885390b Don't replace an alias in llvm.used with its target.
When we replace an internal alias with its target, be careful not to
replace the entry in llvm.used (and llvm.compiler_used).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181524 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-09 17:22:59 +00:00
Benjamin Kramer
a6ff92a975 InstCombine: Don't just copy known bits from the first operand of an srem.
That's obviously wrong. Conservatively restrict it to the sign bit, which
matches the original intention of this analysis. Fixes PR15940.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181518 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-09 16:32:32 +00:00
Arnold Schwaighofer
c121f5dc26 LoopVectorizer: Don't assert on the absence of induction variables
A computable loop exit count does not imply the presence of an induction
variable. Scalar evolution can return a value for an infinite loop.

Fixes PR15926.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181495 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-09 00:32:18 +00:00
Daniel Malea
f7f4184710 Revert 181475 as the DebugIR tests are breaking (automake) buildbots that re-use build dirs
- the temporaries "-debug.ll" files generated by DebugIR pass are considered tests, even though they are not



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181476 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-08 21:55:31 +00:00
Daniel Malea
0fd09cd99b DebugIR tests -- lit tests for the line number transform
- simple one-function case
- function-calling case
- external function calling case
- exception throwing case
- vector case

Note: these tests are somewhat coupled to the current format of debug metadata.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181469 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-08 21:03:00 +00:00
Arnold Schwaighofer
280e1df858 LoopVectorizer: Improve reduction variable identification
The two nested loops were confusing and also conservative in identifying
reduction variables. This patch replaces them by a worklist based approach.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181369 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-07 21:55:37 +00:00
Arnold Schwaighofer
eb95cec176 LoopVectorize: getConsecutiveVector must respect signed arithmetic
We were passing an i32 to ConstantInt::get where an i64 was needed and we must
also pass the sign if we pass negatives numbers. The start index passed to
getConsecutiveVector must also be signed.

Should fix PR15882.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181286 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-07 04:37:05 +00:00
David Majnemer
8ec23cb07e InstCombine: (X ^ signbit) + C -> X + (signbit ^ C)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181249 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-06 21:21:31 +00:00
Jean-Luc Duprat
0aa2b8800c Test results verified using FileCheck rather than grep | count
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181234 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-06 18:45:16 +00:00
Andrew Trick
fcf79528da Rotate multi-exit loops even if the latch was simplified.
Test case by Michele Scandale!

Fixes PR10293: Load not hoisted out of loop with multiple exits.

There are few regressions with this patch, now tracked by
rdar:13817079, and a roughly equal number of improvements. The
regressions are almost certainly back luck because LoopRotate has very
little idea of whether rotation is profitable. Doing better requires a
more comprehensive solution.

This checkin is a quick fix that lacks generality (PR10293 has
a counter-example). But it trivially fixes the case in PR10293 without
interfering with other cases, and it does satify the criteria that
LoopRotate is a loop canonicalization pass that should avoid
heuristics and special cases.

I can think of two approaches that would probably be better in
the long run. Ultimately they may both make sense.

(1) LoopRotate should check that the current header would make a good
loop guard, and that the loop does not already has a sufficient
guard. The artifical SimplifiedLoopLatch check would be unnecessary,
and the design would be more general and canonical. Two difficulties:

- We need a strong guarantee that we won't endlessly rotate, so the
  analysis would need to be precise in order to avoid the
  SimplifiedLoopLatch precondition.

- Analysis like this are usually based on SCEV, which we don't want to
  rely on.

(2) Rotate on-demand in late loop passes. This could even be done by
shoving the loop back on the queue after the optimization that needs
it. This could work well when we find LICM opportunities in
multi-branch loops. This requires some work, and it doesn't really
solve the problem of SCEV wanting a loop guard before the analysis.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181230 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-06 17:58:18 +00:00
Jean-Luc Duprat
81fa2abc85 Fix add4.ll test cmdline so that it passes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181219 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-06 17:18:47 +00:00
Jean-Luc Duprat
c5cf6e5365 Provide InstCombines for the following 3 cases:
A * (1 - (uitofp i1 C)) -> select C, 0, A
B * (uitofp i1 C) -> select C, B, 0
select C, 0, A + select C, B, 0 -> select C, B, A

These come up in code that has been hand-optimized from a select to a linear blend, 
on platforms where that may have mattered. We want to undo such changes 
with the following transform:
A*(1 - uitofp i1 C) + B*(uitofp i1 C) -> select C, A, B



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181216 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-06 16:55:50 +00:00
Nadav Rotem
4ee312bac1 Revert r164763 because it introduces new shuffles.
Thanks Nick Lewycky for pointing this out.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181177 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-06 02:39:09 +00:00
Matt Arsenault
8b9dc21d6f Fix unchecked uses of DominatorTree in MemoryDependenceAnalysis.
Use unknown results for places where it would be needed

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181176 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-06 02:07:24 +00:00
Rafael Espindola
eaf14786ca Fix const merging when an alias of a const is llvm.used.
We used to disable constant merging not only if a constant is llvm.used, but
also if an alias of a constant is llvm.used. This change fixes that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181175 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-06 01:48:55 +00:00
Arnold Schwaighofer
87defd0924 LoopVectorize: Add support for floating point min/max reductions
Add support for min/max reductions when "no-nans-float-math" is enabled. This
allows us to assume we have ordered floating point math and treat ordered and
unordered predicates equally.

radar://13723044

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181144 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-05 01:54:48 +00:00
Arnold Schwaighofer
c1738fdadd LoopVectorize: We don't need an identity element for min/max reductions
We can just use the initial element that feeds the reduction.

  max(max(x, y), z) == max(max(x,y), max(x,z))

radar://13723044

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181141 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-05 01:54:42 +00:00
Nadav Rotem
4bcd5f888f LoopVectorizer: Add support for if-conversion of PHINodes with 3+ incoming values.
By supporting the vectorization of PHINodes with more than two incoming values we can increase the complexity of nested if statements.

We can now vectorize this loop:

int foo(int *A, int *B, int n) {
  for (int i=0; i < n; i++) {
    int x = 9;
    if (A[i] > B[i]) {
      if (A[i] > 19) {
        x = 3;
      } else if (B[i] < 4 ) {
        x = 4;
      } else {
        x = 5;
      }
    }
    A[i] = x;
  }
}



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181037 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-03 17:42:55 +00:00
Manman Ren
436849be6a TBAA: remove !tbaa from testing cases if not used.
This will make it easier to turn on struct-path aware TBAA since the metadata
format will change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180935 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-02 18:11:35 +00:00
David Majnemer
304099a56d Add a test for the foldSelectICmpAndOr fix committed in r180779.
This tests a case where C1 and C2 were the same but X and Y were different
widths.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180907 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-02 02:44:23 +00:00
Nadav Rotem
fee6969463 SROA: Generate selects instead of shuffles when blending values because this is the cannonical form.
Shuffles are more difficult to lower and we usually don't touch them, while we do optimize selects more often.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180875 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-01 19:53:30 +00:00
Jim Grosbach
10cc563bfe Revert "InstCombine: Fold more shuffles of shuffles."
This reverts commit r180802

There's ongoing discussion about whether this is the right place to make
this transformation. Reverting for now while we figure it out.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180834 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-01 00:25:27 +00:00
Jim Grosbach
6548096a2e InstCombine: Fold more shuffles of shuffles.
Always fold a shuffle-of-shuffle into a single shuffle when there's only one
input vector in the first place. Continue to be more conservative when there's
multiple inputs.

rdar://13402653
PR15866

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180802 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-30 20:43:52 +00:00
Manman Ren
2dc50d3067 TBAA: remove !tbaa from testing cases if not used.
This will make it easier to turn on struct-path aware TBAA since the metadata
format will change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180796 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-30 17:52:57 +00:00
David Majnemer
defce4cfd6 Fix "Combine bit test + conditional or into simple math"
This fixes the optimization introduced in r179748 and reverted in r179750.

While the optimization was sound, it did not properly respect differences in
bit-width.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180777 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-30 08:57:58 +00:00
Arnold Schwaighofer
8228ffe72d SimplifyCFG: If convert single conditional stores
This resurrects r179957, but adds code that makes sure we don't touch
atomic/volatile stores:

This transformation will transform a conditional store with a preceeding
uncondtional store to the same location:

 a[i] =
 may-alias with a[i] load
 if (cond)
   a[i] = Y

into an unconditional store.

 a[i] = X
 may-alias with a[i] load
 tmp = cond ? Y : X;
 a[i] = tmp

We assume that on average the cost of a mispredicted branch is going to be
higher than the cost of a second store to the same location, and that the
secondary benefits of creating a bigger basic block for other optimizations to
work on outway the potential case where the branch would be correctly predicted
and the cost of the executing the second store would be noticably reflected in
performance.

hmmer's execution time improves by 30% on an imac12,2 on ref data sets. With
this change we are on par with gcc's performance (gcc also performs this
transformation). There was a 1.2 % performance improvement on a ARM swift chip.
Other tests in the test-suite+external seem to be mostly uninfluenced in my
experiments:
This optimization was triggered on 41 tests such that the executable was
different before/after the patch. Only 1 out of the 40 tests (dealII) was
reproducable below 100% (by about .4%). Given that hmmer benefits so much I
believe this to be a fair trade off.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180731 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-29 21:28:24 +00:00
Michael Gottesman
f11a6856cc [objc-arc] Apply the RV optimization to retains next to calls in ObjCARCContract instead of ObjCARCOpts.
Turning retains into retainRV calls disrupts the data flow analysis in
ObjCARCOpts. Thus we move it as late as we can by moving it into
ObjCARCContract.

We leave in the conversion from retainRV -> retain in ObjCARCOpt since
it enables the dataflow analysis.

rdar://10813093

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180698 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-29 06:53:53 +00:00
Shuxin Yang
4d4c54d29f Fix a XOR reassociation bug.
When Reassociator optimize "(x | C1)" ^ "(X & C2)", it may swap the two
subexpressions, however, it forgot to swap cached constants (of C1 and C2)
accordingly.

rdar://13739160


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180676 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-27 18:02:12 +00:00
Michael Gottesman
2c2e85536d [objc-arc] Test cleanups.
Mainly adding paranoid checks for the closing brace of a function to
help with FileCheck error readability. Also some other minor changes.

No actual CHECK changes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180668 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-27 05:25:54 +00:00
Nadav Rotem
7557e521e5 LoopVectorizer: Calculate the number of pointers to disambiguate at runtime based on the numbers of reads and writes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180593 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-26 05:08:59 +00:00
Nadav Rotem
975b1ddf60 LoopVectorizer: No need to generate pointer disambiguation checks between readonly pointers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180570 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-25 19:55:03 +00:00
Arnold Schwaighofer
a4b8b4ccc9 LoopVectorize: Scalarize padded types
This patch disables memory-instruction vectorization for types that need padding
bytes, e.g., x86_fp80 has 10 bytes store size with 6 bytes padding in darwin on
x86_64. Because the load/store vectorization is performed by the bit casting to
a packed vector, which has incompatible memory layout due to the lack of padding
bytes, the present vectorizer produces inconsistent result for memory
instructions of those types.
This patch checks an equality of the AllocSize of a scalar type and allocated
size for each vector element, to ensure that there is no padding bytes and the
array can be read/written using vector operations.

Patch by Daisuke Takahashi!

Fixes PR15758.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180196 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-24 16:16:01 +00:00
Arnold Schwaighofer
b03ad17536 LoopVectorizer: Bail out if we don't have datalayout we need it
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180195 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-24 16:15:58 +00:00
Nadav Rotem
a7d9a6ee63 LoopVectorizer: Fix 15830. When scalarizing and unrolling stores make sure that the order in which the elements are scalarized is the same as the original order.
This fixes a miscompilation in FreeBSD's regex library.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180121 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-23 17:12:42 +00:00
Pekka Jaaskelainen
2e59a125fc Call the potentially costly isAnnotatedParallel() only once.
Made the uniform write test's checks a bit stricter.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180119 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-23 16:44:43 +00:00
Pekka Jaaskelainen
a8958769ea Refuse to (even try to) vectorize loops which have uniform writes,
even if erroneously annotated with the parallel loop metadata.

Fixes Bug 15794: 
"Loop Vectorizer: Crashes with the use of llvm.loop.parallel metadata"



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180081 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-23 08:08:51 +00:00
Anat Shemer
c9090b0723 Changed back (relative to commit 179786) the operations executed when extract(cast) is transformed to cast(extract). It uses the Builder class as before. In addition the result node is added to the Worklist, so all the previous extract users will become the new scalar cast users.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180045 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-22 20:51:10 +00:00
David Blaikie
c462db6d66 Revert "Revert "PR14606: debug info imported_module support""
This reverts commit r179840 with a fix to test/DebugInfo/two-cus-from-same-file.ll

I'm not sure why that test only failed on ARM & MIPS and not X86 Linux, even
though the debug info was clearly invalid on all of them, but this ought to fix
it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179996 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-22 06:12:31 +00:00