Commit Graph

278703 Commits

Author SHA1 Message Date
Craig Topper 23951ec2cd [SelectionDAG] Make getNode calls that take an ArrayRef of SDValue for operands call NewSDValueDbgMsg.
This makes it work better with some build_vector and concat_vectors creations.

Adjust the NewSDValueDbgMsg in getConstant to avoid duplicating the print when it calls getSplatBuildVector since getSplatBuildVector didn't trigger a print before.

llvm-svn: 320783
2017-12-15 01:03:45 +00:00
Craig Topper 5ebf3ac9c2 [X86] Further rearrange the setOperationAction calls to separate the ones that require 512-bit registers OR VLX into separate sections. NFCI
We have several instructions that were introduced in AVX512F that are only available in 512-bit form on KNL. We still make use of them for 128/256 by artificially widening and extracting during isel.

This commit separates these operations from the true 512-bit operations. This way we can qualify the normal 512-bit operations with needing 512-bit register support. And these special operations will get qualified with needing 512-bit registers OR VLX.

The 512-bit register qualification will be introduced in a future patch this just gets everything grouped to minimize deltas on that patch.

llvm-svn: 320782
2017-12-15 01:03:43 +00:00
Craig Topper 07a28f777e [X86] Group setOperationActions related to vXi1 masks together. NFCI
Previously they were sort of interleaved in with XMM/YMM/ZMM action related code.

Trying to separate things so its easier to split 512-bit vectors later.

llvm-svn: 320781
2017-12-15 01:03:42 +00:00
Craig Topper b89bc20a64 [X86] Make ISD::INSERT_SUBVECTOR v8i1 legal with AVX512F because we should be custom lowering inserting v1i1 into v8i1 under this.
I don't have a test case at the moment. Just noticed while auditing things.

llvm-svn: 320780
2017-12-15 01:03:40 +00:00
Craig Topper 212070486d [X86] Move some of the hasVLX qualified code out of the main hasAVX512 block in the X86ISelLowering constructor. NFCI
Move it into the separate hasVLX block later in the constructor.

I'm trying to separate 128/256 and 512-bit related code so we can eventually qualify the hasAVX512 block with support for 512-bit vectors required by the prefer-vector-width feature support being talked about in D41096.

llvm-svn: 320779
2017-12-15 01:03:38 +00:00
Davide Italiano 89419f88bc [ExpressionParser] Fix evaluation failures due to mismatch in C++ versions.
Clang recently switched to C++14 (with GNU extensions) as the default
dialect, but LLDB didn't catch up. This causes failures as LLDB still
evaluates ObjectiveC expressions as Objective C++ using C++98 as standard.

There are things not available in C++98, including, e.g. nullptr.
In some cases Objective-C `nil` is defined as `nullptr` so this causes
an evaluation failure. Switch the default to overcome this issue
(actually, currently lldb evaluates both C++11 and C++14 as C++11,
but that seems a larger change and definitely could be re-evaluated
in the future).

No test as this is currently failing on the LLDB bots after the clang
switch (so, de facto, there's a test already for it).

This is a recommit, with a thinko fixed (the code was previously
placed incorrectly).

<rdar://problem/36011995>

llvm-svn: 320778
2017-12-15 00:50:43 +00:00
Sam Clegg a43c16157d [WebAssembly] Remove extra semicolon. NFC.
llvm-svn: 320777
2017-12-15 00:34:32 +00:00
Saleem Abdulrasool 05e285bcc5 FastISel: support no-PLT PIC calls on ELF x86_64
Add support for properly handling PIC code with no-PLT.  This equates to
`-fpic -fno-plt -O0` with the clang frontend.  External functions are
marked with nonlazybind, which must then be indirected through the GOT.
This allows code to be built without optimizations in PIC mode without
going through the PLT.  Addresses PR35653!

llvm-svn: 320776
2017-12-15 00:32:09 +00:00
Zachary Turner a1eb9432b1 Don't crash in llvm-pdbutil when dumping TypeIndexes with high bit set.
This is a special code that indicates that it's a function id.
While I'm still not certain how to interpret these, we definitely
should *not* be using these values as indices into an array directly.
For now, when we encounter one of these, just print the numeric value.

llvm-svn: 320775
2017-12-15 00:27:49 +00:00
Sam Clegg bafe69026d [WebAssembly] Implement @llvm.global_ctors and @llvm.global_dtors
Summary:
- lowers @llvm.global_dtors by adding @llvm.global_ctors
  functions which register the destructors with `__cxa_atexit`.
- impements @llvm.global_ctors with wasm start functions and linker metadata

See [here](https://github.com/WebAssembly/tool-conventions/issues/25) for more background.

Subscribers: jfb, dschuff, mgorny, jgravelle-google, aheejin, sunfish

Differential Revision: https://reviews.llvm.org/D41211

llvm-svn: 320774
2017-12-15 00:17:10 +00:00
Rui Ueyama 476a73924e Do not create an unnecessary object file in a test.
llvm-svn: 320773
2017-12-15 00:17:04 +00:00
Rui Ueyama 29ceba7961 Fix error messages.
llvm-svn: 320772
2017-12-15 00:07:15 +00:00
Don Hinton 44298f26b6 [debuginfo] Remove obsolete test_debuginfo.pl that was moved to debuginfo-tests.
Summary:
Now that r320495, "[debuginfo-tests] Support moving
debuginfo-tests to llvm/projects," has landed, which includes a local
copy of test_debuginfo.pl, remove the obsolete copy.

Reviewers: zturner, aprantl

Reviewed By: aprantl

Subscribers: llvm-commits, JDevlieghere

Differential Revision: https://reviews.llvm.org/D41260

llvm-svn: 320771
2017-12-15 00:06:26 +00:00
Rui Ueyama fbe68a3584 Use warn() instead of error() to report a bad symbol in a DSO.
Specifically, libwidevinecdm.so in Chrome has such bad symbol.
It seems the BFD linker handles them as local symbols, so instead
of inserting them to the symbol table, we should skip them too.

Differential Revision: https://reviews.llvm.org/D41257

llvm-svn: 320770
2017-12-15 00:01:33 +00:00
Davide Italiano 75dfd9a525 [ExpressionParser] Rollback C++98 as the standard for evaluating.
Some ubuntu bots are failing with this patch in, let me unblock
while I investigate.

llvm-svn: 320769
2017-12-15 00:00:17 +00:00
David Blaikie f157ad444c Remove a non-modular header (& inline it into its one use)
llvm-svn: 320768
2017-12-14 23:45:58 +00:00
Quentin Colombet 063d798acb [TableGen][GlobalISel] Add a common class for all PredicateMatcher
NFC.

llvm-svn: 320767
2017-12-14 23:44:07 +00:00
Alex Lorenz 4c087abe28 Remove duplicate python libclang changes from r320748
llvm-svn: 320766
2017-12-14 23:40:42 +00:00
Erich Keane 47475f9ec7 Correct UnaryTransformTypeLoc to properly initialize.
The initializeLocal function of UnaryTransformTypeLoc missed
the UnderlyingTInfo member.  This caused a null-dereference
issue, as reported in PR23421. This patch correctly initializss 
the UnderlyingTInfo.

llvm-svn: 320765
2017-12-14 23:37:08 +00:00
George Burgess IV 3c85a155c1 [ProfileData] Use a different data structure to save memory.
This change swaps FunctionSamples to a std::map. This saves us around
17% of the memory required to parse sample profiles. To put hard numbers
on this, clang now eats around 1.3GB of RAM instead of 1.6GB while
parsing a 50MB profile.

The CPU time taken by a large profile merge (3.1GB of data across 226
files) is also reduced by ~11% by this patch (1:09.08 vs 1:01.11).

This was split out at the request of reviewers in D41152.

llvm-svn: 320764
2017-12-14 23:32:57 +00:00
Vassil Vassilev 61f6429e32 D40901: Refactor lazy loading of template specializations. NFC
llvm-svn: 320763
2017-12-14 23:30:18 +00:00
Evandro Menezes 27e7f9c809 [Unit][AArch64] Additional tests for target parsing
Add Exynos M2/M3 to extension check.

llvm-svn: 320762
2017-12-14 23:13:04 +00:00
Davide Italiano d416b0b903 [ExpressionParser] Fix evaluation failures due to mismatch in C++ versions.
Clang recently switched to C++14 (with GNU extensions) as the default
dialect, but LLDB didn't catch up. This causes failures as LLDB still
evaluates ObjectiveC expressions as Objective C++ using C++98 as standard.

There are things not available in C++98, including, e.g. nullptr.
In some cases Objective-C `nil` is defined as `nullptr` so this causes
an evaluation failure. Switch the default to overcome this issue
(actually, currently lldb evaluates both C++11 and C++14 as C++11,
but that seems a larger change and definitely could be re-evaluated
in the future).

No test as this is currently failing on the LLDB bots after the clang
switch (so, de facto, there's a test already for it).

<rdar://problem/36011995>

llvm-svn: 320761
2017-12-14 23:11:15 +00:00
Evandro Menezes d123f8ccf1 [AArch64] Test patch
Fix formatting by adding a missing blank line to test new network setup.

llvm-svn: 320760
2017-12-14 23:06:18 +00:00
Davide Italiano f550ed1abd [ClangASTContext] Remove dead stuff found fixing something else.
llvm-svn: 320759
2017-12-14 23:03:35 +00:00
Adrian Prantl c133d8a5be EmitFuncArgumentDbgValue: Prefer stack slots over registers for stack arguments
While investigating LLVM PR22316 (http://llvm.org/bugs/show_bug.cgi?id=22316)
I started wondering if it were not always preferable to emit the
initial DBG_VALUEs for stack arguments as FI locations instead of
describing the first register they get copied into. The advantage of
doing this is that the arguments will be available as soon as the
stack is setup. As illustrated by the testcase in the PR, the first
copy of the FI into a register may be sunk by MachineSink.cpp into a
later basic block. By describing the argument on the stack, we nicely
circumvent this problem.

<rdar://problem/19583723>

Differential Revision: https://reviews.llvm.org/D41135

llvm-svn: 320758
2017-12-14 22:55:06 +00:00
Craig Topper 4341a7b08c [X86] Remove an unnecessary SmallVector that was collecting chains for two SDNode's we're still holding SDValues for. NFCI
We can just get the chains from those SDValues to create the TokenFactor.

llvm-svn: 320757
2017-12-14 22:50:10 +00:00
Matt Arsenault 7d7adf4f2e TLI: Allow using PSV for intrinsic mem operands
llvm-svn: 320756
2017-12-14 22:34:10 +00:00
Dimitry Andric c7bc461298 Don't trigger -Wuser-defined-literals for system headers
Summary:
In D41064, I proposed adding `#pragma clang diagnostic ignored
"-Wuser-defined-literals"` to some of libc++'s headers, since these
warnings are now triggered by clang's new `-std=gnu++14` default:

```
$ cat test.cpp
#include <string>

$ clang -std=c++14 -Wsystem-headers -Wall -Wextra -c test.cpp
In file included from test.cpp:1:
In file included from /usr/include/c++/v1/string:470:
/usr/include/c++/v1/string_view:763:29: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
    basic_string_view<char> operator "" sv(const char *__str, size_t __len)
                            ^
/usr/include/c++/v1/string_view:769:32: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
    basic_string_view<wchar_t> operator "" sv(const wchar_t *__str, size_t __len)
                               ^
/usr/include/c++/v1/string_view:775:33: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
    basic_string_view<char16_t> operator "" sv(const char16_t *__str, size_t __len)
                                ^
/usr/include/c++/v1/string_view:781:33: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
    basic_string_view<char32_t> operator "" sv(const char32_t *__str, size_t __len)
                                ^
In file included from test.cpp:1:
/usr/include/c++/v1/string:4012:24: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
    basic_string<char> operator "" s( const char *__str, size_t __len )
                       ^
/usr/include/c++/v1/string:4018:27: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
    basic_string<wchar_t> operator "" s( const wchar_t *__str, size_t __len )
                          ^
/usr/include/c++/v1/string:4024:28: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
    basic_string<char16_t> operator "" s( const char16_t *__str, size_t __len )
                           ^
/usr/include/c++/v1/string:4030:28: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
    basic_string<char32_t> operator "" s( const char32_t *__str, size_t __len )
                           ^
8 warnings generated.
```

Both @aaron.ballman and @mclow.lists felt that adding this workaround to
the libc++ headers was the wrong way, and it should be fixed in clang
instead.

Here is a proposal to do just that.  I verified that this suppresses the
warning, even when -Wsystem-headers is used, and that the warning is
still emitted for a declaration outside of system headers.

Reviewers: aaron.ballman, mclow.lists, rsmith

Reviewed By: aaron.ballman

Subscribers: mclow.lists, aaron.ballman, andrew, emaste, cfe-commits

Differential Revision: https://reviews.llvm.org/D41080

llvm-svn: 320755
2017-12-14 22:32:24 +00:00
Rui Ueyama ab163a8e9b Add a missing build dependency.
Patch by Chen-Pang He.

llvm-svn: 320754
2017-12-14 22:31:29 +00:00
Yi Kong 2d58d19c48 [ThreadSafetyAnalysis] Fix isCapabilityExpr
There are many more expr types that can be a capability expr, like
CXXThisExpr, CallExpr, MemberExpr. Instead of enumerating all of them,
just check typeHasCapability for any type given.

Also add & and * operators to allowed unary operators.

Differential Revision: https://reviews.llvm.org/D41224

llvm-svn: 320753
2017-12-14 22:24:45 +00:00
Aaron Ballman 802de4f7ac Harmonize GNU- and C++-style attribute spellings.
Most attributes will now use the Clang<"name"> construct to provide both __attribute__((name)) and [[clang::name]] syntaxes for the attribute. Attributes deviating from this should be marked with a comment explaining why they are not supported under both spellings. Common reasons are: the attribute is provided by some other specification that controls the syntax or the attribute cannot be exposed under a particular spelling for some given reason.

Because this is a mechanical change that only introduces new spellings, there are no test cases for the commit.

llvm-svn: 320752
2017-12-14 22:17:09 +00:00
Don Hinton d15d76e2ae [debuginfo] Remove temporary FIXME.
Summary:
Now that r320495, "[debuginfo-tests] Support moving
debuginfo-tests to llvm/projects," has landed, remove temporary FIXME
that supported the old mechanism.

Reviewers: zturner, aprantl

Reviewed By: aprantl

Subscribers: JDevlieghere, cfe-commits

Differential Revision: https://reviews.llvm.org/D41259

llvm-svn: 320751
2017-12-14 22:12:46 +00:00
Zachary Turner 260fe3eca6 Fix many -Wsign-compare and -Wtautological-constant-compare warnings.
Most of the -Wsign-compare warnings are due to the fact that
enums are signed by default in the MS ABI, while the
tautological comparison warnings trigger on x86 builds where
sizeof(size_t) is 4 bytes, so N > numeric_limits<unsigned>::max()
is always false.

Differential Revision: https://reviews.llvm.org/D41256

llvm-svn: 320750
2017-12-14 22:07:03 +00:00
Sanjay Patel 0ab0c1a201 [SimplifyCFG] don't sink common insts too soon (PR34603)
This should solve:
https://bugs.llvm.org/show_bug.cgi?id=34603
...by preventing SimplifyCFG from altering redundant instructions before early-cse has a chance to run.
It changes the default (canonical-forming) behavior of SimplifyCFG, so we're only doing the
sinking transform later in the optimization pipeline.

Differential Revision: https://reviews.llvm.org/D38566

llvm-svn: 320749
2017-12-14 22:05:20 +00:00
Alex Lorenz 34ccadcea9 [libclang] Add support for checking abstractness of records
This patch allows checking whether a C++ record declaration is abstract through
libclang and clang.cindex (Python).

Patch by Johann Klähn!

Differential Revision: https://reviews.llvm.org/D36952

llvm-svn: 320748
2017-12-14 22:01:50 +00:00
Ben Hamilton 5b0c3ad564 Revert "[ClangFormat] IndentWrappedFunctionNames should be true in the google ObjC style"
This reverts commit 37e69667f748e1458b46483b7c1b8f9ba33eec44.

We're going to discuss its ramifications further before making a
conclusion.

llvm-svn: 320747
2017-12-14 21:44:11 +00:00
Matt Arsenault 1117133687 DAG: Expose all MMO flags in getTgtMemIntrinsic
Rather than adding more bits to express every
MMO flag you could want, just directly use the
MMO flags. Also fixes using a bunch of bool arguments to
getMemIntrinsicNode.

On AMDGPU, buffer and image intrinsics should always
have MODereferencable set, but currently there is no
way to do that directly during the initial intrinsic
lowering.

llvm-svn: 320746
2017-12-14 21:39:51 +00:00
Kostya Kortchinsky efe3d3436a [scudo] Refactor ScudoChunk
Summary:
The initial implementation used an ASan like Chunk class that was deriving from
a Header class. Due to potential races, we ended up working with local copies
of the Header and never using the parent class fields. ScudoChunk was never
constructed but cast, and we were using `this` as the pointer needed for our
computations. This was meh.

So we refactored ScudoChunk to be now a series of static functions within the
namespace `__scudo::Chunk` that take a "user" pointer as first parameter (former
`this`). A compiled binary doesn't really change, but the code is more sensible.

Clang tends to inline all those small function (in -O2), but GCC left a few not
inlined, so we add the `INLINE` keyword to all.

Since we don't have `ScudoChunk` pointers anymore, a few variables were renamed
here and there to introduce a clearer distinction between a user pointer
(usually `Ptr`) and a backend pointer (`BackendPtr`).

Reviewers: alekseyshl, flowerhack

Reviewed By: alekseyshl

Subscribers: #sanitizers, llvm-commits

Differential Revision: https://reviews.llvm.org/D41200

llvm-svn: 320745
2017-12-14 21:32:57 +00:00
Krzysztof Parzyszek 470760533a [Hexagon] Generate HVX code for comparisons and selects
llvm-svn: 320744
2017-12-14 21:28:48 +00:00
Eric Liu b99d5e8b62 [clangd] Put all #includes in one block in clangd source files. NFC
Clang-format categorizes and sorts #includes with style. It doesn't make sense
to manually managing #include blocks.

llvm-svn: 320743
2017-12-14 21:22:03 +00:00
Sam Clegg 4273998cf9 [WebAssembly] Add support for init functions linking metadata
Summary:
This change lays the groundwork lowering of @llvm.global_ctors
and @llvm.global_dtors for the wasm object format.  Some parts
of this patch are subset of: https://reviews.llvm.org/D40759

See https://github.com/WebAssembly/tool-conventions/issues/25

Subscribers: jfb, dschuff, jgravelle-google, aheejin, sunfish

Differential Revision: https://reviews.llvm.org/D41208

llvm-svn: 320742
2017-12-14 21:10:03 +00:00
Sam Clegg ea244bf89b Fix -Wreorder warning
Subscribers: aheejin, llvm-commits

Differential Revision: https://reviews.llvm.org/D41255

llvm-svn: 320741
2017-12-14 21:09:31 +00:00
Kamil Rytarowski 271018d216 [Sanitizers] Basic sanitizer Solaris support (PR 33274)
Summary:
This is the first mostly working version of the Sanitizer port to 32-bit Solaris/x86.
It is currently based on Solaris 11.4 Beta.

This part was initially developed inside libsanitizer in the GCC tree and should apply to
both.  Subsequent parts will address changes to clang, the compiler-rt build system
and testsuite.

I'm not yet sure what the right patch granularity is: if it's profitable to split the patch
up, I'd like to get guidance on how to do so.

Most of the changes are probably straightforward with a few exceptions:

* The Solaris syscall interface isn't stable, undocumented and can change within an
  OS release.  The stable interface is the libc interface, which I'm using here, if possible
  using the internal _-prefixed names.

* While the patch primarily target 32-bit x86, I've left a few sparc changes in.  They
  cannot currently be used with clang due to a backend limitation, but have worked
  fine inside the gcc tree.

* Some functions (e.g. largefile versions of functions like open64) only exist in 32-bit
  Solaris, so I've introduced a separate SANITIZER_SOLARIS32 to check for that.

The patch (with the subsequent ones to be submitted shortly) was tested
on i386-pc-solaris2.11.  Only a few failures remain, some of them analyzed, some
still TBD:

    AddressSanitizer-i386-sunos :: TestCases/Posix/concurrent_overflow.cc
    AddressSanitizer-i386-sunos :: TestCases/init-order-atexit.cc
    AddressSanitizer-i386-sunos :: TestCases/log-path_test.cc
    AddressSanitizer-i386-sunos :: TestCases/malloc-no-intercept.c
    AddressSanitizer-i386-sunos-dynamic :: TestCases/Posix/concurrent_overflow.cc
    AddressSanitizer-i386-sunos-dynamic :: TestCases/Posix/start-deactivated.cc
    AddressSanitizer-i386-sunos-dynamic :: TestCases/default_options.cc
    AddressSanitizer-i386-sunos-dynamic :: TestCases/init-order-atexit.cc
    AddressSanitizer-i386-sunos-dynamic :: TestCases/log-path_test.cc
    AddressSanitizer-i386-sunos-dynamic :: TestCases/malloc-no-intercept.c

   SanitizerCommon-Unit :: ./Sanitizer-i386-Test/MemoryMappingLayout.DumpListOfModules
    SanitizerCommon-Unit :: ./Sanitizer-i386-Test/SanitizerCommon.PthreadDestructorIterations

Maybe this is good enough the get the ball rolling.

Reviewers: kcc, alekseyshl

Reviewed By: alekseyshl

Subscribers: srhines, jyknight, kubamracek, krytarowski, fedor.sergeev, llvm-commits, #sanitizers

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D40898

llvm-svn: 320740
2017-12-14 20:14:29 +00:00
Zachary Turner 0f7b735b13 Revert "Fix isPodLike for MSVC and use it in TypeHashing."
This reverts commit ac5edc198eb612f82293850c3488042708b1c5fa.

Apparently this doesn't cover all the bases, so some compilers
and standard libraries still think this is not trivially copyable
even though it is.  Reverting this back to an MSVC-only check for
now so that at least we have some coverage.

llvm-svn: 320739
2017-12-14 19:59:10 +00:00
Hans Wennborg dcb2f44424 Fix a -Wreorder warning
llvm-svn: 320738
2017-12-14 19:51:18 +00:00
Zachary Turner 6021246210 Fix isPodLike for MSVC and use it in TypeHashing.
This should be a better check than using is_trivially_copyable
behind an #ifdef _MSC_VER.

llvm-svn: 320737
2017-12-14 19:41:28 +00:00
Guozhi Wei d22d1b953d [SLPVectorizer] Don't ignore scalar extraction instructions of aggregate value
In SLPVectorizer, the vector build instructions (insertvalue for aggregate type) is passed to BoUpSLP.buildTree, it is treated as UserIgnoreList, so later in cost estimation, the cost of these instructions are not counted. 
For aggregate value, later usage are more likely to be done in scalar registers, either used as individual scalars or used as a whole for function call or return value. Ignore scalar extraction instructions may cause too aggressive vectorization for aggregate values, and slow down performance. So for vectorization of aggregate value, the scalar extraction instructions are required in cost estimation.

Differential Revision: https://reviews.llvm.org/D41139

llvm-svn: 320736
2017-12-14 19:35:43 +00:00
Alex Lorenz 2cfa11a524 Commit missing tests for r320734
llvm-svn: 320735
2017-12-14 19:22:41 +00:00
Alex Lorenz d8ec431143 [Preprocessor] Implement __is_target_{arch|vendor|os|environment} function-like
builtin macros

This patch implements the __is_target_arch, __is_target_vendor, __is_target_os,
and __is_target_environment Clang preprocessor extensions that were proposed by
@compnerd in Bob's cfe-dev post:
http://lists.llvm.org/pipermail/cfe-dev/2017-November/056166.html.

These macros can be used to examine the components of the target triple at
compile time. A has_builtin(is_target_???) preprocessor check can be used to
check for their availability.

__is_target_arch allows you to check if an arch is specified without worring
about a specific subarch, e.g.

__is_target_arch(arm) returns 1 for the target arch "armv7"
__is_target_arch(armv7) returns 1 for the target arch "armv7"
__is_target_arch(armv6) returns 0 for the target arch "armv7"

__is_target_vendor and __is_target_environment match the specific vendor
or environment. __is_target_os matches the specific OS, but
__is_target_os(darwin) will match any Darwin-based OS. "Unknown" can be used
to test if the triple's component is specified.

rdar://35753116

Differential Revision: https://reviews.llvm.org/D41087

llvm-svn: 320734
2017-12-14 19:22:02 +00:00