Commit Graph

21287 Commits

Author SHA1 Message Date
David Blaikie
c7260209a8 Use DILexicalBlockFile, rather than DILexicalBlock, to track discriminator changes to ensure discriminator changes don't introduce new DWARF DW_TAG_lexical_blocks.
Somewhat unnoticed in the original implementation of discriminators, but
it could cause instructions to end up in new, small,
DW_TAG_lexical_blocks due to the use of DILexicalBlock to track
discriminator changes.

Instead, use DILexicalBlockFile which we already use to track file
changes without introducing new scopes, so it works well to track
discriminator changes in the same way.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216239 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 22:45:21 +00:00
Sanjay Patel
d1a09c47d2 name change: isPow2DivCheap -> isPow2SDivCheap
isPow2DivCheap

That name doesn't specify signed or unsigned.

Lazy as I am, I eventually read the function and variable comments. It turns out that this is strictly about signed div. But I discovered that the comments are wrong:

   srl/add/sra

is not the general sequence for signed integer division by power-of-2. We need one more 'sra':

   sra/srl/add/sra

That's the sequence produced in DAGCombiner. The first 'sra' may be removed when dividing by exactly '2', but that's a special case.

This patch corrects the comments, changes the name of the flag bit, and changes the name of the accessor methods.

No functional change intended.

Differential Revision: http://reviews.llvm.org/D5010


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216237 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 22:31:48 +00:00
Robin Morisset
a204592582 Add hooks for emitLeading/TrailingFence
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216232 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 22:09:25 +00:00
Robin Morisset
cf165c36ee Rename AtomicExpandLoadLinked into AtomicExpand
AtomicExpandLoadLinked is currently rather ARM-specific. This patch is the first of
a group that aim at making it more target-independent. See
http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-August/075873.html
for details

The command line option is "atomic-expand"

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216231 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 21:50:01 +00:00
David Blaikie
95ca0fb247 Explicitly pass ownership of the MemoryBuffer to AddNewSourceBuffer using std::unique_ptr
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216223 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 20:44:56 +00:00
Jonathan Roelofs
96c909cc74 Satiate the sanitizer build bot
This fixes a missing initializer from r216182


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216212 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 20:09:15 +00:00
Rafael Espindola
7b4eb02b6d Move some logic to populateLTOPassManager.
This will avoid code duplication in the next commit which calls it directly
from the gold plugin.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216211 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 20:03:44 +00:00
Alex Lorenz
93695d2395 Coverage Mapping: add function's hash to coverage function records.
The profile data format was recently updated and the new indexing api
requires the code coverage tool to know the function's hash as well
as the function's name to get the execution counts for a function.

Differential Revision: http://reviews.llvm.org/D4994


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216207 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 19:23:25 +00:00
Hans Wennborg
eeb828f029 Use returns_nonnull in BumpPtrAllocator and MallocAllocator to avoid null-check in placement new
In both Clang and LLVM, this is a common pattern:

  Size = sizeof(DeclRefExpr) + SomeExtraStuff;
  void *Mem = Context.Allocate(Size, llvm::alignOf<DeclRefExpr>());
  return new (Mem) DeclRefExpr(...);

The annoying thing is that because the default placement-new operator has a
nothrow specification, the compiler will insert a null check of Mem before
calling the DeclRefExpr constructor. This null check is redundant for us,
because we expect the allocation functions to never return null.

By annotating the allocator functions with returns_nonnull, we can optimize
away these checks. Compiling clang with a recent version of Clang and measuring
with:

  $ perf stat -r20 bin/clang.patch -fsyntax-only -w gcc.c && perf stat -r20 bin/clang.orig -fsyntax-only -w gcc.c

Shows a 2.4% speed-up (+- 0.8%).

The pattern occurs in LLVM too. Measuring with -O3 (and now using bzip2.c
instead, because it's smaller):

  $ perf stat -r20 bin/clang.patch -O3 -w bzip2.c  &&  perf stat -r20 bin/clang.orig -O3 -w bzip2.c

Shows 4.4 % speed-up (+- 1%).

If anyone knows of a similar attribute we can use for MSVC, or some other
technique to get rid off the null check there, please let me know.

Differential Revision: http://reviews.llvm.org/D4989

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216192 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 17:10:00 +00:00
Jonathan Roelofs
4c3be1aa0f Add a thread-model knob for lowering atomics on baremetal & single threaded systems
http://reviews.llvm.org/D4984


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216182 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 14:35:47 +00:00
Rafael Espindola
0b994a70b0 Handle inlining in populateLTOPassManager like in populateModulePassManager.
No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216178 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 13:35:30 +00:00
Rafael Espindola
47199c3d0c Move DisableGVNLoadPRE from populateLTOPassManager to PassManagerBuilder.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216174 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 13:13:17 +00:00
Rafael Espindola
fc4bdcdc87 Sort declarations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216171 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 12:39:07 +00:00
Benjamin Kramer
67e5178cef Make format_object_base's destructor protected and non-virtual.
It's not meant to be used with operator delete and this avoids emitting virtual
dtors for every derived format object.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216170 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 11:22:05 +00:00
Robert Khasanov
fec1abaeab [x86] Added _addcarry_ and _subborrow_ intrinsics
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216164 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 09:43:43 +00:00
Robert Khasanov
10dacc4b52 [x86] Broadwell: ADOX/ADCX. Added _addcarryx_u{32|64} intrinsics to LLVM.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216162 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 09:27:00 +00:00
Craig Topper
431bdfc4c1 Repace SmallPtrSet with SmallPtrSetImpl in function arguments to avoid needing to mention the size.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216158 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 05:55:13 +00:00
Craig Topper
e88b796285 Remove custom implementations of max/min in StringRef that was originally added to work an old gcc bug. I believe its been fixed by now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216156 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 04:31:10 +00:00
Quentin Colombet
0d15213307 Add isInsertSubreg property.
This patch adds a new property: isInsertSubreg and the related target hooks:
TargetIntrInfo::getInsertSubregInputs and
TargetInstrInfo::getInsertSubregLikeInputs to specify that a target specific
instruction is a (kind of) INSERT_SUBREG.

The approach is similar to r215394.

<rdar://problem/12702965>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216139 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-20 23:49:36 +00:00
Quentin Colombet
400bc218f8 Mention the right target hook in the comment on isExtractSubreg property.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216137 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-20 23:25:28 +00:00
Quentin Colombet
dac67649f2 Add isExtractSubreg property.
This patch adds a new property: isExtractSubreg and the related target hooks:
TargetIntrInfo::getExtractSubregInputs and
TargetInstrInfo::getExtractSubregLikeInputs to specify that a target specific
instruction is a (kind of) EXTRACT_SUBREG.

The approach is similar to r215394.

<rdar://problem/12702965>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216130 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-20 21:51:26 +00:00
Alexey Samsonov
fa210acc3b Fix null reference creation in SelectionDAG constructor.
Store TargetSelectionDAGInfo as a pointer instead of a reference:
getSelectionDAGInfo() may not be implemented for certain backends
(e.g. it's not currently implemented for R600).

This bug is reported by UBSan.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216129 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-20 21:40:15 +00:00
Alexey Samsonov
a046b4149c Cleanup: Delete seemingly unused reference to MachineDominatorTree from ScheduleDAGInstrs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216124 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-20 20:57:26 +00:00
Duncan P. N. Exon Smith
5012f1db20 X86: Align the stack on word boundaries in LowerFormalArguments()
The goal of the patch is to implement section 3.2.3 of the AMD64 ABI
correctly.  The controlling sentence is, "The size of each argument gets
rounded up to eightbytes.  Therefore the stack will always be eightbyte
aligned." The equivalent sentence in the i386 ABI page 37 says, "At all
times, the stack pointer should point to a word-aligned area."  For both
architectures, the stack pointer is not being rounded up to the nearest
eightbyte or word between the last normal argument and the first
variadic argument.

Patch by Thomas Jablin!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216119 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-20 19:40:59 +00:00
Alexey Samsonov
ada5f2a2c7 Fix null reference creation in ScheduleDAGInstrs constructor call.
Both MachineLoopInfo and MachineDominatorTree may be null in ScheduleDAGMI
constructor call. It is undefined behavior to take references to these values.

This bug is reported by UBSan.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216118 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-20 19:36:05 +00:00
Andrew Trick
e18eb616a8 Tweak CFGPrinter to wrap very long names.
I added wrapping to the CFGPrinter a while back so the -view-cfg
output is actually viewable. I've since enountered very long mangled
names with the same problem, so I'm slightly tweaking this code to
work in that case.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216087 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-20 17:38:12 +00:00
NAKAMURA Takumi
ae8d297579 Constants.h: Fix possible typo in r216015. [-Wdocumentation]
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216043 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-20 04:22:47 +00:00
Hans Wennborg
06de8a10d2 BumpPtrAllocator: don't accept 0 for the alignment parameter
It seems unnecessary to have to use an extra branch to check for this special case.

http://reviews.llvm.org/D4945

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216036 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 23:35:33 +00:00
Rafael Espindola
b12ab608fe Split parseAssembly into parseAssembly and parseAssemblyInto.
This should restore the functionality of parsing new code into an existing
module without the confusing interface.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216031 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 22:05:47 +00:00
Duncan P. N. Exon Smith
8db4ddb14a IR: Fix a missed case when threading OnlyIfReduced through ConstantExpr
In r216015 I missed propagating `OnlyIfReduced` through the inline
versions of `getGetElementPtr()` (I was relying on compile failures on
mismatches between the header and source signatures to get them all).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216023 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 21:18:21 +00:00
Duncan P. N. Exon Smith
13f5c5896d verify-uselistorder: Force -preserve-bc-use-list-order
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216022 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 21:08:27 +00:00
Rafael Espindola
6825609779 fix the gcc build
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216018 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 20:06:25 +00:00
Duncan P. N. Exon Smith
b03916a88b IR: Fix ConstantExpr::replaceUsesOfWithOnConstant()
Change `ConstantExpr` to follow the model the other constants are using:
only malloc a replacement if it's going to be used.  This fixes a subtle
bug where if an API user had used `ConstantExpr::get()` already to
create the replacement but hadn't given it any users, we'd delete the
replacement.

This relies on r216015 to thread `OnlyIfReduced` through
`ConstantExpr::getWithOperands()`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216016 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 20:03:35 +00:00
Duncan P. N. Exon Smith
e2215571e5 IR: Thread OnlyIfReduced through ConstantExpr::getWithOperands()
In order to change `ConstantExpr::replaceUsesOfWithOnConstant()` to work
like other constants (e.g., using `ConstantArray::getImpl()`), thread
`OnlyIfReduced` through as necessary.  When `OnlyIfReduced` is false,
there's no functionality change.  When it's true, if there's no constant
folding or type changes `nullptr` is returned instead of the new
constant.

`ConstantExpr::replaceUsesOfWithOnConstant()` will be updated to use the
"true" version in a follow-up commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216015 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 19:45:37 +00:00
Rafael Espindola
a96d94aa6e Fix the MSVC build.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216014 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 19:45:15 +00:00
Juergen Ributzka
f08cddcf56 Reapply [FastISel] Let the target decide first if it wants to materialize a constant (215588).
Note: This was originally reverted to track down a buildbot error. This commit
exposed a latent bug that was fixed in r215753. Therefore it is reapplied
without any modifications.

I run it through SPEC2k and SPEC2k6 for AArch64 and it didn't introduce any new
regeressions.

Original commit message:
This changes the order in which FastISel tries to materialize a constant.
Originally it would try to use a simple target-independent approach, which
can lead to the generation of inefficient code.

On X86 this would result in the use of movabsq to materialize any 64bit
integer constant - even for simple and small values such as 0 and 1. Also
some very funny floating-point materialization could be observed too.

On AArch64 it would materialize the constant 0 in a register even the
architecture has an actual "zero" register.

On ARM it would generate unnecessary mov instructions or not use mvn.

This change simply changes the order and always asks the target first if it
likes to materialize the constant. This doesn't fix all the issues
mentioned above, but it enables the targets to implement such
optimizations.

Related to <rdar://problem/17420988>.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216006 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 19:05:24 +00:00
Rafael Espindola
548f2b6e8f Don't own the buffer in object::Binary.
Owning the buffer is somewhat inflexible. Some Binaries have sub Binaries
(like Archive) and we had to create dummy buffers just to handle that. It is
also a bad fit for IRObjectFile where the Module wants to own the buffer too.

Keeping this ownership would make supporting IR inside native objects
particularly painful.

This patch focuses in lib/Object. If something elsewhere used to own an Binary,
now it also owns a MemoryBuffer.

This patch introduces a few new types.

* MemoryBufferRef. This is just a pair of StringRefs for the data and name.
  This is to MemoryBuffer as StringRef is to std::string.
* OwningBinary. A combination of Binary and a MemoryBuffer. This is needed
  for convenience functions that take a filename and return both the
  buffer and the Binary using that buffer.

The C api now uses OwningBinary to avoid any change in semantics. I will start
a new thread to see if we want to change it and how.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216002 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 18:44:46 +00:00
Rafael Espindola
9b29ff99c0 Modernize the .ll parsing interface.
* Use StringRef instead of std::string&
* Return a std::unique_ptr<Module> instead of taking an optional module to write
  to (was not really used).
* Use current comment style.
* Use current naming convention.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215989 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 16:58:54 +00:00
Duncan P. N. Exon Smith
7116af637c Reapply r215966, r215965, r215964, r215963, r215960, r215959, r215958, and r215957
This reverts commit r215981, which reverted the above commits because
MSVC std::equal asserts on nullptr iterators, and thes commits
introduced an `ArrayRef::equals()` on empty ArrayRefs.

ArrayRef was changed not to use std::equal in r215986.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215987 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 16:39:58 +00:00
Duncan P. N. Exon Smith
8c20a93bac ADT: Avoid using std::equal in ArrayRef::equals
MSVC's STL has a bug in `std::equal()`: it asserts on nullptr iterators,
causing a block revert in r215981.  This works around that by re-writing
`ArrayRef::equals()` to do the work itself.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215986 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 16:36:21 +00:00
Aaron Ballman
93710f07f0 Reverting r215966, r215965, r215964, r215963, r215960, r215959, r215958, and r215957 (these commits all rely on previous commits) due to build breakage. These commits cause failed assertions when testing Clang using MSVC 2013. The asserts are triggered from the std::equal call within ArrayRef::equals due to being passed invalid input (ArrayRef.begin() is returning a nullptr which is problematic).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215981 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 14:59:02 +00:00
Craig Topper
25fc910167 Prevent use of the implicit copy constructor on SmallPtrSetImpl. An accidental copy caused my SmallPtrSet->SmallPtrSetImpl conversion commit to fail the other day.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215971 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 06:57:14 +00:00
Rafael Espindola
3f4ed32b43 Make it explicit that ExecutionEngine takes ownership of the modules.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215967 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 04:04:25 +00:00
Duncan P. N. Exon Smith
6238162cc5 IR: Factor out replaceUsesOfWithOnConstantImpl(), NFC
Factor out common code, and take advantage of the new function to
add early returns to the callers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215964 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 02:16:51 +00:00
Duncan P. N. Exon Smith
45d53fd4c4 IR: Split up Constant{Array,Vector}::get(), NFC
Introduce `getImpl()` that tries the simplification logic from `get()`
and then gives up.  This allows the logic to be reused elsewhere in a
follow-up commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215963 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 02:11:30 +00:00
Duncan P. N. Exon Smith
1cfbb6358c IR: Reduce RAUW traffic in ConstantExpr
Avoid RAUW-ing `ConstantExpr` when an operand changes unless the new
`ConstantExpr` already has users.  This prevents the RAUW from rippling
up the expression tree unnecessarily.

This commit indirectly adds test coverage for r215953 (this is how I
came across the bug).

This is part of PR20515.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215960 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 01:12:53 +00:00
Duncan P. N. Exon Smith
fe0bf8fbf9 IR: Replace uses of ConstantAggrUniqueMap with ConstantUniqueMap
Now that `ConstantAggrUniqueMap` and `ConstantUniqueMap` work the same
way, change the aggregates to use the new one.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215959 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 01:02:18 +00:00
Duncan P. N. Exon Smith
78c0b35bf7 IR: Rewrite ConstantUniqueMap
Rewrite `ConstantUniqueMap` to be more similar to
`ConstantAggrUniqueMap`.

  - Use a `DenseMap` with custom MapInfo instead of a `std::map` with
    linear lookups and deletion.
  - Don't waste memory explicitly storing (heavyweight) keys.

Only `ConstantExpr` and `InlineAsm` actually use this data structure, so
I also updated them to use it.

This code cleanup is a precursor to reducing RAUW traffic on
`ConstantExpr` -- I felt badly adding a new (linear) call to
`ConstantUniqueMap::FindExistingKey`, so this designs away the concern.

A follow-up commit will transition the users of `ConstantAggrUniqueMap`
over.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215957 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 00:42:32 +00:00
Kevin Enderby
f759032ccd Make llvm-objdump handle both arm and thumb disassembly from the same Mach-O
file with -macho, the Mach-O specific object file parser option.

After some discussion I chose to do this implementation contained in the logic
of llvm-objdump’s MachODump.cpp using a second disassembler for thumb when
needed and with updates mostly contained in the MachOObjectFile class.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215931 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-18 20:21:02 +00:00
Tim Northover
049ffbbdf2 TableGen: allow use of uint64_t for available features mask.
ARM in particular is getting dangerously close to exceeding 32 bits worth of
possible subtarget features. When this happens, various parts of MC start to
fail inexplicably as masks get truncated to "unsigned".

Mostly just refactoring at present, and there's probably no way to test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215887 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-18 11:49:42 +00:00