Commit Graph

2134 Commits

Author SHA1 Message Date
Benjamin Kramer
81c1d4095f Factor the iterators of ImmutableSet/ImmutableMap into a common base class
This simplifies code quite a bit and brings the iterators closer to
C++'s iterator concept. No functional change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232319 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-15 13:26:03 +00:00
David Majnemer
3d849bdb47 ImmutableSet: Rename Self to SelfTy to make it more clear it is a type
No functional change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232317 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-15 07:09:20 +00:00
David Majnemer
7a447391cc PostOrderIterator: Remove stray semicolon
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232316 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-15 07:09:18 +00:00
David Majnemer
f5cb5de29b Restore the gcc build
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232314 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-15 06:11:24 +00:00
David Blaikie
bc5ada697f Remove iterator I accidentally left behind
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232312 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-15 03:21:20 +00:00
David Blaikie
afae7ef18d Remove use of reserved identifier _Iterator
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232311 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-15 03:18:21 +00:00
David Blaikie
22536735d5 Remove use of reserved identifiers in Twine
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232310 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-15 03:17:28 +00:00
David Blaikie
635114fece Remove use of reserved identifier and some excess 'inline' usage
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232309 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-15 03:11:26 +00:00
David Blaikie
e2935ee61b Remove reserved identifier & some unnecessary 'inline'
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232308 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-15 03:11:24 +00:00
David Blaikie
baddd24f31 Remove use of reserved identifier
& some unnecessary 'inline' keywords

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232307 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-15 03:03:41 +00:00
David Blaikie
3cfe5cb8b3 Remove use of unreserved identifier (_Self)
And some unnecessary inline keywords

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232304 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-15 01:42:28 +00:00
Benjamin Kramer
c0cc039a57 array_pod_sort: Since we're checking the length anyways also ignore one-element ranges
Sorting them is obviously a noop and we can skip the libc call. This is
surprisingly common in clang. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232265 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-14 14:53:14 +00:00
Frederic Riss
a11c9307f6 [ADT] IntervalMap: use AlignedCharArrayUnion.
Currently IntervalMap would assert when used with keys bigger than host
pointers. This patch uses the AlignedCharArrayUnion functionality to
overcome that limitation.

Differential Revision: http://reviews.llvm.org/D8268

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232079 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-12 18:45:07 +00:00
Ed Schouten
71706a01b0 Add support for Nuxi CloudABI.
CloudABI is a POSIX-like runtime environment built around the concept of
capability-based security. More details:

	https://github.com/NuxiNL/cloudlibc

CloudABI uses its own ELFOSABI number. This number has been allocated by
the maintainers of ELF a couple of days ago.

Reviewed by:	echristo


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231681 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-09 18:40:45 +00:00
Chaoren Lin
cc8f2c2156 Revert "[ADT] fail-fast iterators for DenseMap"
This reverts commit 4b7263d855.

r231125 http://reviews.llvm.org/D7931

This was causing many LLDB tests to fail on OS X, Linux, and FreeBSD.

https://bpaste.net/show/6a23e1f53623

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231214 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-04 06:05:37 +00:00
Sanjoy Das
4b7263d855 [ADT] fail-fast iterators for DenseMap
This patch was landed in r231035 and reverted because it was buggy.
This is fixed version of the same change.

Summary:
This patch is an attempt at making `DenseMapIterator`s "fail-fast".
Fail-fast iterators that have been invalidated due to insertion into
the host `DenseMap` deterministically trip an assert (in debug mode)
on access, instead of non-deterministically hitting memory corruption
issues.

Reviewers: dexonsmith, dberlin, ruiu, chandlerc

Reviewed By: chandlerc

Subscribers: yaron.keren, chandlerc, llvm-commits

Differential Revision: http://reviews.llvm.org/D7931

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231125 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-03 20:46:45 +00:00
David Blaikie
7462aeac16 DeltaAlgorithm: Provide protected default copy ctor for use by test derived class.
Without this, use of this copy ctor is deprecated in C++11 due to the
presence of a user-declared dtor.

Marking the class final is just a little extra security that there are
no further derived classes that may then end up using the intermediate
base class's copy assignment operator and cause slicing to occur.

I didn't bother marking the other (non-test) base class final, since it
has reference members so it won't have any implicit assignment operators
anyway. Open to ideas on that, though.

We probably want a warning about use of a slicing assignment operator,
then I wouldn't worry so much about marking the class as final.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231114 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-03 19:53:04 +00:00
David Blaikie
f5e27edc7b [Small]BitVector::reference: Explicitly default copy construction as it is deprecated in C++11 in the presence of explicit copy assignment.
I tried making these private & friended to the BitVector, but that
didn't work - there's one use of BitVector::reference in Clang that
actually copies it into a local variable & uses it from there, rather
than just using the result of op[] in a temporary expression.

Whether or not this is desired is debatable (we could just fix that one
use in Clang) & it's not clear which way the C++ standard falls on this
for std::bitset's reference type (it has the same bug at least in
libstdc++, but Clang's -Wdeprecated doesn't flag it, because it's in a
standard header)

While it was only BitVector::reference's copy ctor that was referenced
by user code, I made SmallBitVector::reference's copy ctor public too,
for consistency.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231099 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-03 18:39:00 +00:00
David Blaikie
6283687346 Twine: Explicitly default the copy ctor as it's otherwise deprecated in C++11 by the presence of a user-declared copy assignment operator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231094 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-03 18:29:25 +00:00
David Blaikie
88f45e5ecd DenseMapIterator: Avoid explicitly declaring the copy ctor as this makes the copy assignment operator deprecated in C++11
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231093 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-03 18:29:23 +00:00
Sanjoy Das
e288a5bb3b Revert "[ADT] fail-fast iterators for DenseMap"
This reverts commit r231035.  It breaks clang.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231050 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-03 01:59:38 +00:00
Sanjoy Das
47ffd6e993 [ADT] fail-fast iterators for DenseMap
Summary:
This patch is an attempt at making `DenseMapIterator`s "fail-fast".
Fail-fast iterators that have been invalidated due to insertion into
the host `DenseMap` deterministically trip an assert (in debug mode)
on access, instead of non-deterministically hitting memory corruption
issues.

Reviewers: dexonsmith, dberlin, ruiu, chandlerc

Reviewed By: chandlerc

Subscribers: yaron.keren, chandlerc, llvm-commits

Differential Revision: http://reviews.llvm.org/D7931

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231035 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-02 23:29:37 +00:00
Benjamin Kramer
0b08b96fdd IndexedMap: Document why SmallVector<T, 0> is preferable here.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231028 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-02 22:20:22 +00:00
Benjamin Kramer
3ad0e2cd45 SmallVector: Allow initialization and assignment from initializer_list.
Modeled after std::vector.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231015 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-02 21:16:04 +00:00
Benjamin Kramer
bd06347b1a Fix a really bad typo in my last commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230922 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-01 23:56:19 +00:00
Benjamin Kramer
24c79ab7cc ArrayRef: Put back std::equal for operator== with a check for the empty ArrayRefs
This has the nice property of compiling down to memcmp when feasible. An empty
ArrayRef can have a nullptr in its Data field. I didn't find anything in the
standard speaking against std::equal(nullptr, nullptr, nullptr) begin valid but
MSVC asserts. The way libstdc++ lowers std::equal down to memcmp also makes
invoking std::equal with a nullptr undefined behavior so checking is the only
way to be safe.

The extra check doesn't cost us perf either because we're essentially peeling
the loop header away from the rotated loop.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230920 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-01 23:35:20 +00:00
Benjamin Kramer
c255d35a10 ArrayRef: Remove the equals helper with many arguments.
With initializer lists there is a really neat idiomatic way to write
this, 'ArrayRef.equals({1, 2, 3, 4, 5})'. Remove the equal method which
always had a hard limit on the number of arguments. I considered
rewriting it with variadic templates but that's not really a good fit
for a function with homogeneous arguments.

'ArrayRef == {1, 2, 3, 4, 5}' would've been even more awesome, but C++11
doesn't allow init lists with binary operators.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230907 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-01 21:05:05 +00:00
Benjamin Kramer
ce770dda2c IndexedMap: Default to SmallVector<T, 0>
This looks ridiculous but SmallVector's realloc tricks really help with
large vectors of PODs, such as our virtreg IndexedMap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230866 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-28 20:15:07 +00:00
Benjamin Kramer
9f9dcf8046 Reduce double set lookups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230798 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-27 21:43:14 +00:00
Benjamin Kramer
42f72e2c16 Sync the __builtin_expects for our 3 quadratically probed hash table implementations.
This assumes that
  a) finding the bucket containing the value is LIKELY
  b) finding an empty bucket is LIKELY
  c) growing the table is UNLIKELY

I also switched the a) and b) cases for SmallPtrSet as we seem to use
the set mostly more for insertion than for checking existence.

In a simple benchmark consisting of 2^21 insertions of 2^20 unique
pointers into a DenseMap or SmallPtrSet a few percent speedup on average,
but nothing statistically significant.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230232 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-23 16:41:36 +00:00
Peter Collingbourne
5a81e14385 Introduce bitset metadata format and bitset lowering pass.
This patch introduces a new mechanism that allows IR modules to co-operatively
build pointer sets corresponding to addresses within a given set of
globals. One particular use case for this is to allow a C++ program to
efficiently verify (at each call site) that a vtable pointer is in the set
of valid vtable pointers for the class or its derived classes. One way of
doing this is for a toolchain component to build, for each class, a bit set
that maps to the memory region allocated for the vtables, such that each 1
bit in the bit set maps to a valid vtable for that class, and lay out the
vtables next to each other, to minimize the total size of the bit sets.

The patch introduces a metadata format for representing pointer sets, an
'@llvm.bitset.test' intrinsic and an LTO lowering pass that lays out the globals
and builds the bitsets, and documents the new feature.

Differential Revision: http://reviews.llvm.org/D7288

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230054 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-20 20:30:47 +00:00
Benjamin Kramer
fa3b207447 Make the static instance of None just const.
This way there shouldn't be any unused variable warnings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230010 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-20 13:16:05 +00:00
Justin Bogner
a074de6ff4 Disallow implicit conversions from None to integer types
This fixes an error introduced in r228934 where None was converted to
an int instead of the int being converted to an Optional as intended.
We make that sort of mistake a compile error by changing NoneType into
a scoped enum.

Finally, provide a static NoneType called None to avoid forcing all
users to spell it NoneType::None.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229980 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-20 07:28:28 +00:00
Aaron Ballman
8b0b0a8524 I believe we no longer require LLVM_HAS_INITIALIZER_LISTS; it's supported in MSVC 2013 and GCC. Added a trivial test to ensure the ArrayRef initializer list constructor is called and behaves as expected.
If any of the bots complain (perhaps due to an antiquated version of an STL implementation), I will revert.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229502 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-17 15:37:53 +00:00
Chandler Carruth
d99cd97f85 Switch our index sequence away from template aliases and just use
classes. We can't use template aliases because on MSVC they don't appear
to work correctly in the common usage such as Format.h.

Many thanks to Zach for doing all the testing and debugging here. I just
slotted the fix into the code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229362 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-16 08:22:35 +00:00
Aaron Ballman
66981fe208 Removing LLVM_DELETED_FUNCTION, as MSVC 2012 was the last reason for requiring the macro. NFC; LLVM edition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229340 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 22:54:22 +00:00
Benjamin Kramer
aee01b35e4 Format: Modernize using variadic templates.
Introduces a subset of C++14 integer sequences in STLExtras. This is
just enough to support unpacking a std::tuple into the arguments of
snprintf, we can add more of it when it's actually needed.

Also removes an ancient macro hack that leaks a macro into the global
namespace. Clean up users that made use of the convenient hack.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229337 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 22:15:41 +00:00
Aaron Ballman
d898d31ebc Removing LLVM_EXPLICIT, as MSVC 2012 was the last reason for requiring the macro. NFC; LLVM edition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229335 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 22:00:20 +00:00
Benjamin Kramer
5a4e2d2d64 FoldingSet: Replace faux variadics with real variadics. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229328 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 20:12:17 +00:00
Benjamin Kramer
5d6f0738e3 Remove LLVM_HAS_VARIADIC_TEMPLATES and all the faux variadic workarounds guarded by it.
We no longer support compilers without variadic template support.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229324 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 19:34:28 +00:00
Benjamin Kramer
f7803d51f4 Reapply r229142 with some enable_if magic to avoid memcpying between differing types.
Original commit message:
SmallVector: Resolve a long-standing fixme by using the existing unitialized_copy dispatch.

This makes append() use memcpy for trivially copyable types.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229149 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 20:45:14 +00:00
Benjamin Kramer
802f6b37e5 Revert r229142. It breaks the world for unknown reasons.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229144 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 19:45:28 +00:00
Benjamin Kramer
36013dd6a1 SmallVector: Resolve a long-standing fixme by using the existing unitialized_copy dispatch.
This makes append() use memcpy for trivially copyable types.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229142 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 19:20:39 +00:00
Chandler Carruth
02d6288667 Re-sort #include lines using my handy dandy ./utils/sort_includes.py
script. This is in preparation for changes to lots of include lines.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229088 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 09:09:03 +00:00
Akira Hatanaka
ac844bf562 [LinkModules] Change the way ModuleLinker merges triples.
This commit makes the following changes:

- Stop issuing a warning when the triples' string representations do not match
  exactly if the Triple objects generated from the strings compare equal.
 
- On Apple platforms, choose the triple that has the larger minimum version
  number. 

rdar://problem/16743513

Differential Revision: http://reviews.llvm.org/D7591


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228999 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 00:40:41 +00:00
Benjamin Kramer
d913d9d2c3 MathExtras: Bring Count(Trailing|Leading)Ones and CountPopulation in line with countTrailingZeros
Update all callers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228930 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-12 15:35:40 +00:00
Benjamin Kramer
c70b2070db BitVector: Remove manual bit width dispatch, this is handled by templates
NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228922 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-12 14:02:58 +00:00
Duncan P. N. Exon Smith
a9a077681d ADT: Allow up to 18 arguments in hash_combine()
I just realized that the specialized metadata node patch I'm about to
commit won't compile on old compilers.  Bump `hash_combine()`'s support
for non-variadic templates to 18 (I tested this by reversing the logic
in the #ifdef).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228629 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-09 23:21:05 +00:00
Benjamin Kramer
ff53b757ea SmallVector: Move emplace_back to SmallVectorImpl.
This resolves the strange effect that emplace_back is only available
when the type contained in the vector is not trivially copyable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228496 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-07 16:41:02 +00:00
Duncan P. N. Exon Smith
97ec768f7f ADT: Add int64_t interoperability to APSInt
Add some API to `APSInt` to make it easier to compare with `int64_t`.

  - `APSInt::compareValues(APSInt, APSInt)` returns 1, -1 or 0 for
    greater, lesser, or equal, doing the right thing for mismatched
    "has-sign" and bitwidths.  This is just like `isSameValue()` (and is
    now the implementation of it).
  - `APSInt::get(int64_t)` gets a signed `APSInt`.
  - `operator<(int64_t)`, etc., are implemented trivially via `get()`
    and `compareValues()`.
  - Also added `APSInt::getUnsigned(uint64_t)` to make it easier to test
    `compareValues()`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228239 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-05 00:17:43 +00:00
Reid Kleckner
cfa2c32166 Remove useless call to isOSCygMing()
This used to do something when we modeled the Cygwin and MinGW
environments as distinct OSs, but now it is not needed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228229 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-04 23:17:19 +00:00
David Blaikie
fb29a70867 STLExtras: Provide less/equal functors with templated function call operators, plus a deref'ing functor template utility
Similar to the C++14 void specializations of these templates, useful as
a stop-gap until LLVM switches to '14.

Example use-cases in tblgen because I saw some functors that looked like
they could be simplified/refactored.

Reviewers: dexonsmith

Differential Revision: http://reviews.llvm.org/D7324

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227828 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-02 18:35:10 +00:00
Benjamin Kramer
c400986f57 FoldingSetVectorIterator is just a subset of pointee_iterator, remove it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227761 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-01 19:26:05 +00:00
Adam Nemet
d46418f870 Include cstddef in EquivalenceClasses.h
This is to try to appease bots complaining that ptrdiff_t is undefined in
LoopAccessAnalysis.cpp.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227757 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-01 17:21:06 +00:00
Alex Rosenberg
f6c7255d5f Add the triple for the Sony Playstation®4.
Lots more to follow.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227060 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-25 22:46:59 +00:00
Alexei Starovoitov
4fe85c7548 BPF backend
Summary:
V8->V9:
- cleanup tests

V7->V8:
- addressed feedback from David:
- switched to range-based 'for' loops
- fixed formatting of tests

V6->V7:
- rebased and adjusted AsmPrinter args
- CamelCased .td, fixed formatting, cleaned up names, removed unused patterns
- diffstat: 3 files changed, 203 insertions(+), 227 deletions(-)

V5->V6:
- addressed feedback from Chandler:
- reinstated full verbose standard banner in all files
- fixed variables that were not in CamelCase
- fixed names of #ifdef in header files
- removed redundant braces in if/else chains with single statements
- fixed comments
- removed trailing empty line
- dropped debug annotations from tests
- diffstat of these changes:
  46 files changed, 456 insertions(+), 469 deletions(-)

V4->V5:
- fix setLoadExtAction() interface
- clang-formated all where it made sense

V3->V4:
- added CODE_OWNERS entry for BPF backend

V2->V3:
- fix metadata in tests

V1->V2:
- addressed feedback from Tom and Matt
- removed top level change to configure (now everything via 'experimental-backend')
- reworked error reporting via DiagnosticInfo (similar to R600)
- added few more tests
- added cmake build
- added Triple::bpf
- tested on linux and darwin

V1 cover letter:
---------------------
recently linux gained "universal in-kernel virtual machine" which is called
eBPF or extended BPF. The name comes from "Berkeley Packet Filter", since
new instruction set is based on it.
This patch adds a new backend that emits extended BPF instruction set.

The concept and development are covered by the following articles:
http://lwn.net/Articles/599755/
http://lwn.net/Articles/575531/
http://lwn.net/Articles/603983/
http://lwn.net/Articles/606089/
http://lwn.net/Articles/612878/

One of use cases: dtrace/systemtap alternative.

bpf syscall manpage:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b4fc1a460f3017e958e6a8ea560ea0afd91bf6fe

instruction set description and differences vs classic BPF:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/filter.txt

Short summary of instruction set:
- 64-bit registers
  R0      - return value from in-kernel function, and exit value for BPF program
  R1 - R5 - arguments from BPF program to in-kernel function
  R6 - R9 - callee saved registers that in-kernel function will preserve
  R10     - read-only frame pointer to access stack
- two-operand instructions like +, -, *, mov, load/store
- implicit prologue/epilogue (invisible stack pointer)
- no floating point, no simd

Short history of extended BPF in kernel:
interpreter in 3.15, x64 JIT in 3.16, arm64 JIT, verifier, bpf syscall in 3.18, more to come in the future.

It's a very small and simple backend.
There is no support for global variables, arbitrary function calls, floating point, varargs,
exceptions, indirect jumps, arbitrary pointer arithmetic, alloca, etc.
From C front-end point of view it's very restricted. It's done on purpose, since kernel
rejects all programs that it cannot prove safe. It rejects programs with loops
and with memory accesses via arbitrary pointers. When kernel accepts the program it is
guaranteed that program will terminate and will not crash the kernel.

This patch implements all 'must have' bits. There are several things on TODO list,
so this is not the end of development.
Most of the code is a boiler plate code, copy-pasted from other backends.
Only odd things are lack or < and <= instructions, specialized load_byte intrinsics
and 'compare and goto' as single instruction.
Current instruction set is fixed, but more instructions can be added in the future.

Signed-off-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>

Subscribers: majnemer, chandlerc, echristo, joerg, pete, rengolin, kristof.beyls, arsenm, t.p.northover, tstellarAMD, aemerson, llvm-commits

Differential Revision: http://reviews.llvm.org/D6494

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227008 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-24 17:51:26 +00:00
Chandler Carruth
6f409cbc05 [PM] Rework how the TargetLibraryInfo pass integrates with the new pass
manager to support the actual uses of it. =]

When I ported instcombine to the new pass manager I discover that it
didn't work because TLI wasn't available in the right places. This is
a somewhat surprising and/or subtle aspect of the new pass manager
design that came up before but I think is useful to be reminded of:

While the new pass manager *allows* a function pass to query a module
analysis, it requires that the module analysis is already run and cached
prior to the function pass manager starting up, possibly with
a 'require<foo>' style utility in the pass pipeline. This is an
intentional hurdle because using a module analysis from a function pass
*requires* that the module analysis is run prior to entering the
function pass manager. Otherwise the other functions in the module could
be in who-knows-what state, etc.

A somewhat surprising consequence of this design decision (at least to
me) is that you have to design a function pass that leverages
a module analysis to do so as an optional feature. Even if that means
your function pass does no work in the absence of the module analysis,
you have to handle that possibility and remain conservatively correct.
This is a natural consequence of things being able to invalidate the
module analysis and us being unable to re-run it. And it's a generally
good thing because it lets us reorder passes arbitrarily without
breaking correctness, etc.

This ends up causing problems in one case. What if we have a module
analysis that is *definitionally* impossible to invalidate. In the
places this might come up, the analysis is usually also definitionally
trivial to run even while other transformation passes run on the module,
regardless of the state of anything. And so, it follows that it is
natural to have a hard requirement on such analyses from a function
pass.

It turns out, that TargetLibraryInfo is just such an analysis, and
InstCombine has a hard requirement on it.

The approach I've taken here is to produce an analysis that models this
flexibility by making it both a module and a function analysis. This
exposes the fact that it is in fact safe to compute at any point. We can
even make it a valid CGSCC analysis at some point if that is useful.
However, we don't want to have a copy of the actual target library info
state for each function! This state is specific to the triple. The
somewhat direct and blunt approach here is to turn TLI into a pimpl,
with the state and mutators in the implementation class and the query
routines primarily in the wrapper. Then the analysis can lazily
construct and cache the implementations, keyed on the triple, and
on-demand produce wrappers of them for each function.

One minor annoyance is that we will end up with a wrapper for each
function in the module. While this is a bit wasteful (one pointer per
function) it seems tolerable. And it has the advantage of ensuring that
we pay the absolute minimum synchronization cost to access this
information should we end up with a nice parallel function pass manager
in the future. We could look into trying to mark when analysis results
are especially cheap to recompute and more eagerly GC-ing the cached
results, or we could look at supporting a variant of analyses whose
results are specifically *not* cached and expected to just be used and
discarded by the consumer. Either way, these seem like incremental
enhancements that should happen when we start profiling the memory and
CPU usage of the new pass manager and not before.

The other minor annoyance is that if we end up using the TLI in both
a module pass and a function pass, those will be produced by two
separate analyses, and thus will point to separate copies of the
implementation state. While a minor issue, I dislike this and would like
to find a way to cleanly allow a single analysis instance to be used
across multiple IR unit managers. But I don't have a good solution to
this today, and I don't want to hold up all of the work waiting to come
up with one. This too seems like a reasonable thing to incrementally
improve later.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226981 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-24 02:06:09 +00:00
Lang Hames
efd63170c8 [ADT] Add move operations to SmallVector<T,N> from SmallVectorImpl<T>.
This makes it possible to move between SmallVectors of different sizes.

Thanks to Dave Blaikie and Duncan Smith for patch feedback.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226899 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-23 06:25:17 +00:00
Michael Gottesman
eb71fa415e [tinyptrvector] Add in a MutableArrayRef implicit conversion operator to complement the ArrayRef implicit conversion operator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226428 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-19 03:25:33 +00:00
Michael Gottesman
75dd736002 Change using => typedef to please the MSVC bots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226425 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-19 02:38:16 +00:00
Michael Gottesman
b0b28ca485 Hide the state of TinyPtrVector and remove the single element constructor.
There is no reason for this state to be exposed as public. The single element
constructor was superfulous in light of the single element ArrayRef
constructor.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226424 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-19 02:09:54 +00:00
Chandler Carruth
1b279144ec [cleanup] Re-sort all the #include lines in LLVM using
utils/sort_includes.py.

I clearly haven't done this in a while, so more changed than usual. This
even uncovered a missing include from the InstrProf library that I've
added. No functionality changed here, just mechanical cleanup of the
include order.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225974 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 11:23:27 +00:00
Chandler Carruth
6c92f6eb6a [ADT] Remove the unused default constructor for iterator_range.
This default constructor is a bit weird. It left the range in an invalid
state. That might be reasonable so that you can construct a local
iterator range and assign to it based on some logic to compute the range
you want. If folks would like to support that use case, I can add it
back, but in 238-odd usages none have actually wanted to do this. ;]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225592 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-11 01:16:26 +00:00
Ahmed Bougacha
8a19eb2a85 [ADT][SmallVector] Flip an assert comparison to avoid overflows yielding false-negatives. NFC.
r221973 changed SmallVector::operator[] to use size_t instead of unsigned.

Before that, on 64bit platforms, when a large index (say -1) was passed,
truncating it to unsigned avoided an overflow when computing 'begin() + idx',
and failed the range checking assertion, as expected.
With r221973, idx isn't truncated, so the addition wraps to
'(char*)begin() - 1', and doesn't fire anymore when it should have done so.

This commit changes the comparison to instead compute 'end() - begin()'
(i.e., 'size()'), which avoids potentially overflowing additions, and
correctly triggers the assertion when values such as -1 are passed.
Note that the problem already existed before that revision, on platforms
where sizeof(size_t) == sizeof(unsigned).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225338 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-07 02:42:01 +00:00
Tom Stellard
a31ae5e0b0 Triple: Add amdgcn triple
This will be used for AMD GPUs with the Graphics Core Next architecture,
which are currently using by the r600 triple.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225276 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-06 18:00:00 +00:00
Michael Gottesman
16c2e77337 Convert SmallMapVector from a class to a struct.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225158 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-05 08:55:19 +00:00
Michael Gottesman
31379e2e69 Revert "Just use a using directive in SmallMapVector instead of inheriting from MapVector itself."
This reverts commit r225059. I think MSVC 2012 has a problem with this. This is
an attempt to fix one of the MSVC 2012 bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225065 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-01 13:54:05 +00:00
Chandler Carruth
4b77e07165 Revert r225053: Add an ArrayRef upcasting constructor from ArrayRef<U*> -> ArrayRef<T*> where T is a base of U.
This appears to have broken at least the windows build bots due to
compile errors in the predicate that didn't simply supress the overload.
I'm not sure what the fix is, and the bots have been broken for a long
time now so I'm just reverting until Michael can figure out a fix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225064 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-01 13:01:25 +00:00
Michael Gottesman
81b226e135 Just use a using directive in SmallMapVector instead of inheriting from MapVector itself.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225059 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-01 08:05:41 +00:00
Michael Gottesman
69338a993e Add 2x constructors for TinyPtrVector, one that takes in one elemenet and the other that takes in an ArrayRef<EltTy>
Currently one can only construct an empty TinyPtrVector. These are just missing
elements of the API.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225055 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-31 23:33:24 +00:00
Michael Gottesman
4ba553c0f3 Add a SmallMapVector class that is a MapVector with a Map of SmallDenseMap and a Vector of SmallVector.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225054 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-31 23:33:21 +00:00
Michael Gottesman
735f1df049 Add an ArrayRef upcasting constructor from ArrayRef<U*> -> ArrayRef<T*> where T is a base of U.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225053 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-31 23:33:18 +00:00
Rafael Espindola
a21d820952 Add segmented stack support for DragonFlyBSD.
Patch by Michael Neumann.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224936 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-29 15:47:28 +00:00
David Blaikie
1b2c37ecce Update SmallPtrSet::insert's doc comment to match the new return type
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224619 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-19 21:45:11 +00:00
Michael Ilseman
9ecdca9115 Silence more static analyzer warnings.
Add in definedness checks for shift operators, null checks when
pointers are assumed by the code to be non-null, and explicit
unreachables.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224255 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-15 18:48:43 +00:00
Aaron Ballman
978aeec05a Silencing a *lot* of -Wsign-compare warnings; NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224194 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-13 16:53:15 +00:00
Michael Ilseman
3f0e8837be Clean up static analyzer warnings.
Clang's static analyzer found several potential cases of undefined
behavior, use of un-initialized values, and potentially null pointer
dereferences in tablegen, Support, MC, and ADT. This cleans them up
with specific assertions on the assumptions of the code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224154 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-12 21:48:03 +00:00
Duncan P. N. Exon Smith
4bedb48751 Bitcode: Use unsigned char to record MDStrings
`MDString`s can have arbitrary characters in them.  Prevent an assertion
that fired in `BitcodeWriter` because of sign extension by copying the
characters into the record as `unsigned char`s.

Based on a patch by Keno Fischer; fixes PR21882.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224077 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 23:34:30 +00:00
Benjamin Kramer
2cd5836249 Make the DenseMap bucket type configurable and use a smaller bucket for DenseSet.
DenseSet used to be implemented as DenseMap<Key, char>, which usually doubled
the memory footprint of the map. Now we use a compressed set so the second
element uses no memory at all. This required some surgery on DenseMap as
all accesses to the bucket now have to go through methods; this should
have no impact on the behavior of DenseMap though. The new default bucket
type for DenseMap is a slightly extended std::pair as we expose it through
DenseMap's iterator and don't want to break any existing users.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223588 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-06 19:22:44 +00:00
Benjamin Kramer
51df2c2a10 Reapply "LLVMContext: Store APInt/APFloat directly into the ConstantInt/FP DenseMaps."
This reapplies r223478 with a fix for 32 bit targets.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223586 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-06 13:12:56 +00:00
Benjamin Kramer
d46a8180c0 Revert "LLVMContext: Store APInt/APFloat directly into the ConstantInt/FP DenseMaps."
Somehow made DenseMap probe on forever on 32 bit machines.
This reverts commit r223478.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223546 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-06 00:02:31 +00:00
Benjamin Kramer
472e9cc4bc LLVMContext: Store APInt/APFloat directly into the ConstantInt/FP DenseMaps.
Required some APInt massaging to get proper empty/tombstone values. Apart
from making the code a bit simpler this also reduces the bucket size of
the ConstantInt map from 32 to 24 bytes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223478 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-05 17:03:01 +00:00
Duncan P. N. Exon Smith
afcbfb40fb ADT: Remove GetStringMapEntryFromValue()
It relies on undefined behaviour, since `StringMapEntry<>` is not
a standard layout type.  There are no users anyway.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223439 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-05 01:41:36 +00:00
Alexey Samsonov
59d867405a Revert "Fix UBSan report in StringMap implementation."
This reverts commit r223402. Some bots fail with -Winvalid-offsetof
warning.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223407 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-04 23:00:50 +00:00
Alexey Samsonov
8bc0067071 Fix UBSan report in StringMap implementation.
Use offsetof() instead of a member access within null pointer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223402 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-04 22:45:31 +00:00
Rafael Espindola
a300b8d7e4 Use size_type in the interface exposed by SmallVector.
This matches std::vector and should avoid unnecessary masking to 32 bits
when calling them on o 64 bits system.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223365 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-04 14:40:35 +00:00
Duncan P. N. Exon Smith
59c9cb75d2 ADT: Rename argument in emplace_back_impl
Rename a functor argument in r223201 from `emplace` to `construct` to
reduce confusion.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223212 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-03 05:53:24 +00:00
Duncan P. N. Exon Smith
ba2915d05c ADT: Add SmallVector<>::emplace_back(): fixup
Add missing `void` return type from `!LLVM_HAS_VARIADIC_TEMPLATES` case
in r223201.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223202 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-03 04:49:16 +00:00
Duncan P. N. Exon Smith
fe03508abd ADT: Add SmallVector<>::emplace_back()
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223201 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-03 04:45:09 +00:00
Pete Cooper
dfc69d2c27 Use a typed enum instead of 'unsigned char' for packed field. NFC.
This makes it easier to debug Twine as the 'Kind' fields now show their enum values in lldb and not escaped characters.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223178 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-02 23:34:23 +00:00
Tom Stellard
fcf4242b9b Triple: Add AMDHSA operating system type
This operating system type represents the AMD HSA runtime,
and will be required by the R600 backend in order to generate
correct code for this runtime.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223124 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-02 16:45:47 +00:00
Simon Pilgrim
53a43d38df Tidied up target triple OS detection. NFC
Use Triple::isOS*() helper functions where possible.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222622 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-22 19:12:10 +00:00
Michael Ilseman
deb068a5cb Update template specialization to reflect API changes.
po_iterator_storage's insertEdge was updated to reflect the API
changes from many of our insert methods in r222334, however the
template specialization for external storage was not updated. This
updates the specialization.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222446 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-20 19:33:30 +00:00
Saleem Abdulrasool
06f9f40a1e ADT: windows itanium targets msvcrt.dll
Update the isOSMSVCRT to correctly identify that windows-itanium uses
msvcrt.dll.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222389 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-19 21:55:31 +00:00
David Blaikie
c58082616a Add missing header
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222337 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-19 08:12:55 +00:00
David Blaikie
5401ba7099 Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool>
This is to be consistent with StringSet and ultimately with the standard
library's associative container insert function.

This lead to updating SmallSet::insert to return pair<iterator, bool>,
and then to update SmallPtrSet::insert to return pair<iterator, bool>,
and then to update all the existing users of those functions...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222334 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-19 07:49:26 +00:00
David Blaikie
1d4f28c6bc Remove StringMap::GetOrCreateValue in favor of StringMap::insert
Having two ways to do this doesn't seem terribly helpful and
consistently using the insert version (which we already has) seems like
it'll make the code easier to understand to anyone working with standard
data structures. (I also updated many references to the Entry's
key and value to use first() and second instead of getKey{Data,Length,}
and get/setValue - for similar consistency)

Also removes the GetOrCreateValue functions so there's less surface area
to StringMap to fix/improve/change/accommodate move semantics, etc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222319 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-19 05:49:42 +00:00
David Blaikie
8f4a49f41a Make StringSet::insert return pair<iterator, bool> like other self-associative containers
StringSet is still a bit dodgy in that it exposes the raw iterator of
the StringMap parent, which exposes the weird detail that StringSet
actually has a 'value'... but anyway, this is useful for a handful of
clients that want to reference the newly inserted/persistent string data
in the StringSet/Map/Entry/thing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222302 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-19 02:56:00 +00:00
Rafael Espindola
28b45aa83e Use a memcpy so that type based alias analysis sees the change.
The other option would be to do something like

if (that.isSingleWord())
  VAL = that.VAL;
else
  pVal = that.pVal

This bug was causing 86TTI::getIntImmCost to be miscompiled in a LTO
bootstrap in stage2, causing the build of stage3 to fail.

LLVM is getting quiet good at exploiting this. Not sure if there is anything
a sanitizer could do to help

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222294 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-19 01:02:22 +00:00
Reid Kleckner
8083adcaca Revert "ADT: correctly report isMSVCEnvironment for windows itanium"
This reverts commit r222180.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222188 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-17 22:55:59 +00:00