Commit Graph

82 Commits

Author SHA1 Message Date
Yaxun (Sam) Liu 3b172f60c6 [HIP] Fix -fgpu-rdc for Windows
This patch fixes issues for -fgpu-rdc for Windows MSVC
toolchain:

Fix COFF specific section flags and remove section types
in llvm-mc input file for Windows.

Escape fatbin path in llvm-mc input file.

Add -triple option to llvm-mc.

Put __hip_gpubin_handle in comdat when it has linkonce_odr
linkage.

Reviewed by: Artem Belevich

Differential Revision: https://reviews.llvm.org/D115039
2021-12-06 16:42:23 -05:00
Yaxun (Sam) Liu 80072fde61 [CUDA][HIP] Allow comdat for kernels
Two identical instantiations of a template function can be emitted by two TU's
with linkonce_odr linkage without causing duplicate symbols in linker. MSVC
also requires these symbols be in comdat sections. Linux does not require
the symbols in comdat sections to be merged by linker but by default
clang puts them in comdat sections.

If a template kernel is instantiated identically in two TU's. MSVC requires
that them to be in comdat sections, otherwise MSVC linker will diagnose them as
duplicate symbols. However, currently clang does not put instantiated template
kernels in comdat sections, which causes link error for MSVC.

This patch allows putting instantiated template kernels into comdat sections.

Reviewed by: Artem Belevich, Reid Kleckner

Differential Revision: https://reviews.llvm.org/D112492
2021-11-10 16:42:23 -05:00
Jay Foad 1b758925ad [IR] Merge createReplacementInstr into ConstantExpr::getAsInstruction
createReplacementInstr was a trivial wrapper around
ConstantExpr::getAsInstruction, which also inserted the new instruction
into a basic block. Implement this directly in getAsInstruction by
adding an InsertBefore parameter and change all callers to use it. NFC.

A follow-up patch will remove createReplacementInstr.

Differential Revision: https://reviews.llvm.org/D112791
2021-10-29 15:02:58 +01:00
Uday Bondhugula 9fb9c6b91e [Clang][NFC] Clang CUDA codegen clean-up
Update an instance of dyn_cast -> cast and other NFC clang-tidy fixes
for Clang CUDA codegen.

Differential Revision: https://reviews.llvm.org/D112284
2021-10-27 11:07:20 +05:30
Nikita Popov 6d3e7c783b [OpaquePtr] Remove uses of CreateConstGEP1_32() without element type
Remove uses of to-be-deprecated API. I've fallen back to calling
getPointerElementType() in some cases where the correct type wasn't
immediately obvious to me.
2021-07-17 18:32:36 +02:00
Erich Keane eba69b59d1 Reimplement __builtin_unique_stable_name-
The original version of this was reverted, and @rjmcall provided some
advice to architect a new solution.  This is that solution.

This implements a builtin to provide a unique name that is stable across
compilations of this TU for the purposes of implementing the library
component of the unnamed kernel feature of SYCL.  It does this by
running the Itanium mangler with a few modifications.

Because it is somewhat common to wrap non-kernel-related lambdas in
macros that aren't present on the device (such as for logging), this
uniquely generates an ID for all lambdas involved in the naming of a
kernel. It uses the lambda-mangling number to do this, except replaces
this with its own number (starting at 10000 for readabililty reasons)
for lambdas used to name a kernel.

Additionally, this implements itself as constexpr with a slight catch:
if a name would be invalidated by the use of this lambda in a later
kernel invocation, it is diagnosed as an error (see the Sema tests).

Differential Revision: https://reviews.llvm.org/D103112
2021-05-27 07:12:20 -07:00
Yaxun (Sam) Liu 98575708da [CUDA][HIP] Fix device template variables
Currently clang does not emit device template variables
instantiated only in host functions, however, nvcc is
able to do that:

https://godbolt.org/z/fneEfferY

This patch fixes this issue by refactoring and extending
the existing mechanism for emitting static device
var ODR-used by host only. Basically clang records
device variables ODR-used by host code and force
them to be emitted in device compilation. The existing
mechanism makes sure these device variables ODR-used
by host code are added to llvm.compiler-used, therefore
they are guaranteed not to be deleted.

It also fixes non-ODR-use of static device variable by host code
causing static device variable to be emitted and registered,
which should not.

Reviewed by: Artem Belevich

Differential Revision: https://reviews.llvm.org/D102237
2021-05-12 11:13:29 -04:00
Jan Svoboda 6a72ed239c [clang] NFC: Fix range-based for loop warnings related to decl lookup 2021-04-19 18:31:31 +02:00
Yaxun (Sam) Liu d5c0f00e21 [CUDA][HIP] Mark device var used by host only
Add device variables to llvm.compiler.used if they are
ODR-used by either host or device functions.

This is necessary to prevent them from being
eliminated by whole-program optimization
where the compiler has no way to know a device
variable is used by some host code.

Reviewed by: Artem Belevich

Differential Revision: https://reviews.llvm.org/D98814
2021-04-17 11:25:25 -04:00
Simon Pilgrim 2901dc7575 Don't directly dereference getAs<> casts to avoid potential null dereferences. NFCI.
Replace with castAs<> which asserts the cast is valid.

Fixes a number of static analyzer warnings.
2021-04-06 12:24:19 +01:00
Yaxun (Sam) Liu cc9477166a [CUDA][HIP] add __builtin_get_device_side_mangled_name
Add builtin function __builtin_get_device_side_mangled_name
to get device side manged name for functions and global
variables, which can be used to get symbol address of kernels
or variables by mangled name in dynamically loaded
bundled code objects at run time.

Reviewed by: Artem Belevich

Differential Revision: https://reviews.llvm.org/D99301
2021-03-25 15:25:29 -04:00
Yaxun (Sam) Liu 5cf2a37f12 [HIP] Emit kernel symbol
Currently clang uses stub function to launch kernel. This is inconvenient
to interop with C++ programs since the stub function has different name
as kernel, which is required by ROCm debugger.

This patch emits a variable symbol which has the same name as the kernel
and uses it to register and launch the kernel. This allows C++ program to
launch a kernel by using the original kernel name.

Reviewed by: Artem Belevich

Differential Revision: https://reviews.llvm.org/D86376
2021-03-01 16:31:40 -05:00
Yaxun (Sam) Liu 47acdec1dd [CUDA][HIP] Support accessing static device variable in host code for -fgpu-rdc
For -fgpu-rdc mode, static device vars in different TU's may have the same name.
To support accessing file-scope static device variables in host code, we need to give them
a distinct name and external linkage. This can be done by postfixing each static device variable with
a distinct CUID (Compilation Unit ID) hash.

Since the static device variables have different name across compilation units, now we let
them have external linkage so that they can be looked up by the runtime.

Reviewed by: Artem Belevich, and Jon Chesterfield

Differential Revision: https://reviews.llvm.org/D85223
2021-02-24 18:23:45 -05:00
Yaxun (Sam) Liu a3ce7f5cd2 [HIP] Fix managed variable linkage
Currently managed variables are emitted as undefined symbols, which
causes difficulty for diagnosing undefined symbols for non-managed
variables.

This patch transforms managed variables in device compilation so that
they can be emitted as normal variables.

Reviewed by: Artem Belevich

Differential Revision: https://reviews.llvm.org/D96195
2021-02-23 22:34:45 -05:00
Yaxun (Sam) Liu b008ea304d [CUDA][HIP] Fix device variable linkage
For -fgpu-rdc, shadow variables should not be internalized, otherwise
they cannot be accessed by other TUs. This is necessary because
the shadow variable of external device variables are always
emitted as undefined symbols, which need to resolve to a global
symbols.

Managed variables need to be emitted as undefined symbols
in device compilations.

Reviewed by: Artem Belevich

Differential Revision: https://reviews.llvm.org/D95901
2021-02-05 15:11:12 -05:00
Michael Liao 01bf529db2 Recommit of a2fdf9d4d7.
- The failures are all cc1-based tests due to the missing `-aux-triple` options,
which is always prepared by the driver in CUDA/HIP compilation.
- Add extra check on the missing aux-targetinfo to prevent crashing.

[hip][cuda] Enable extended lambda support on Windows.

- On Windows, extended lambda has extra issues due to the numbering
schemes are different between the host compilation (Microsoft C++ ABI)
and the device compilation (Itanium C++ ABI. Additional device side
lambda number is required per lambda for the host compilation to
correctly mangle the device-side lambda name.
- A hybrid numbering context `MSHIPNumberingContext` is introduced to
number a lambda for both host- and device-compilations.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D69322

This reverts commit 4874ff0241.
2021-02-05 11:27:30 -05:00
Nico Weber 4874ff0241 Revert "[hip][cuda] Enable extended lambda support on Windows."
This reverts commit a2fdf9d4d7.
Slightly speculative, seeing several cuda tests fail on this
Windows bot: http://45.33.8.238/win/32620/step_7.txt
2021-02-04 07:10:46 -05:00
Michael Liao a2fdf9d4d7 [hip][cuda] Enable extended lambda support on Windows.
- On Windows, extended lambda has extra issues due to the numbering
  schemes are different between the host compilation (Microsoft C++ ABI)
  and the device compilation (Itanium C++ ABI. Additional device side
  lambda number is required per lambda for the host compilation to
  correctly mangle the device-side lambda name.
- A hybrid numbering context `MSHIPNumberingContext` is introduced to
  number a lambda for both host- and device-compilations.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D69322
2021-02-04 01:38:29 -05:00
Yaxun (Sam) Liu 0b2af1a288 [NFC][CUDA] Refactor registering device variable
Extract registering device variable to CUDA runtime codegen function since it
will be called in multiple places.

Reviewed by: Artem Belevich

Differential Revision: https://reviews.llvm.org/D95558
2021-02-03 14:29:51 -05:00
Yaxun (Sam) Liu 622eaa4a4c [HIP] Support __managed__ attribute
This patch implements codegen for __managed__ variable attribute for HIP.

Diagnostics will be added later.

Differential Revision: https://reviews.llvm.org/D94814
2021-01-22 11:43:58 -05:00
Bevin Hansson 101309fe04 [AST] Change return type of getTypeInfoInChars to a proper struct instead of std::pair.
Followup to D85191.

This changes getTypeInfoInChars to return a TypeInfoChars
struct instead of a std::pair of CharUnits. This lets the
interface match getTypeInfo more closely.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D86447
2020-10-13 13:26:56 +02:00
Yaxun (Sam) Liu dc6a0b0ec7 [HIP] Align device binary
To facilitate faster loading of device binaries and share them among processes,
HIP runtime favors their alignment being 4096 bytes. HIP runtime can load
unaligned device binaries, however, aligning them at 4096 bytes results in
faster loading and less shared memory usage.

This patch adds an option -bundle-align to clang-offload-bundler which allows
bundles to be aligned at specified alignment. By default it is 1, which is NFC
compared to existing format.

This patch then aligns embedded fat binary and device binary inside fat binary
at 4096 bytes.

It has been verified this change does not cause significant overall file size increase
for typical HIP applications (less than 1%).

Differential Revision: https://reviews.llvm.org/D88734
2020-10-02 18:10:44 -04:00
Yaxun (Sam) Liu 849d4405f5 [HIP] Fix rocm detection
Do not detect device library by default in rocm detector.
Only detect device library in Rocm and HIP toolchain.

Separate detection of HIP runtime and Rocm device library.

Detect rocm path by version file in host toolchains.

Also added detecting rocm version and printing rocm
installation path and version with -v.

Fixed include path and device library detection for
ROCm 3.5.

Added --hip-version option. Renamed --hip-device-lib-path
to --rocm-device-lib-path.

Fixed default value for -fhip-new-launch-api.

Added default -std option for HIP.

Differential Revision: https://reviews.llvm.org/D82930
2020-07-10 23:20:15 -04:00
Michael Liao b952d799ca [cuda][hip] Fix `RegisterVar` function prototype.
Summary:
- `RegisterVar` has `void` return type and `size_t` in its variable size
  parameter in HIP or CUDA 9.0+.

Reviewers: tra, yaxunl

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D77398
2020-04-03 12:57:09 -04:00
Michael Liao cb6389360b Fix GCC warning on enum class bitfield. NFC. 2020-03-28 10:20:34 -04:00
Michael Liao 5be9b8cbe2 [cuda][hip] Add CUDA builtin surface/texture reference support.
Summary: - Re-commit after fix Sema checks on partial template specialization.

Reviewers: tra, rjmccall, yaxunl, a.sidorin

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76365
2020-03-27 17:18:49 -04:00
Artem Belevich fe8063e1a0 Revert "[cuda][hip] Add CUDA builtin surface/texture reference support."
This reverts commit 6a9ad5f3f4.
The patch breaks CUDA copmilation.

Differential Revision: https://reviews.llvm.org/D76365
2020-03-27 10:01:38 -07:00
Michael Liao 6a9ad5f3f4 [cuda][hip] Add CUDA builtin surface/texture reference support.
Summary:
- Even though the bindless surface/texture interfaces are promoted,
  there are still code using surface/texture references. For example,
  [PR#26400](https://bugs.llvm.org/show_bug.cgi?id=26400) reports the
  compilation issue for code using `tex2D` with texture references. For
  better compatibility, this patch proposes the support of
  surface/texture references.
- Due to the absent documentation and magic headers, it's believed that
  `nvcc` does use builtins for texture support. From the limited NVVM
  documentation[^nvvm] and NVPTX backend texture/surface related
  tests[^test], it's believed that surface/texture references are
  supported by replacing their reference types, which are annotated with
  `device_builtin_surface_type`/`device_builtin_texture_type`, with the
  corresponding handle-like object types, `cudaSurfaceObject_t` or
  `cudaTextureObject_t`, in the device-side compilation. On the host
  side, that global handle variables are registered and will be
  established and updated later when corresponding binding/unbinding
  APIs are called[^bind]. Surface/texture references are most like
  device global variables but represented in different types on the host
  and device sides.
- In this patch, the following changes are proposed to support that
  behavior:
  + Refine `device_builtin_surface_type` and
    `device_builtin_texture_type` attributes to be applied on `Type`
    decl only to check whether a variable is of the surface/texture
    reference type.
  + Add hooks in code generation to replace that reference types with
    the correponding object types as well as all accesses to them. In
    particular, `nvvm.texsurf.handle.internal` should be used to load
    object handles from global reference variables[^texsurf] as well as
    metadata annotations.
  + Generate host-side registration with proper template argument
    parsing.

---
[^nvvm]: https://docs.nvidia.com/cuda/pdf/NVVM_IR_Specification.pdf
[^test]: https://raw.githubusercontent.com/llvm/llvm-project/master/llvm/test/CodeGen/NVPTX/tex-read-cuda.ll
[^bind]: See section 3.2.11.1.2 ``Texture reference API` in [CUDA C Programming Guide](https://docs.nvidia.com/cuda/pdf/CUDA_C_Programming_Guide.pdf).
[^texsurf]: According to NVVM IR, `nvvm.texsurf.handle` should be used.  But, the current backend doesn't have that supported. We may revise that later.

Reviewers: tra, rjmccall, yaxunl, a.sidorin

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76365
2020-03-26 14:44:52 -04:00
Yaxun (Sam) Liu 22c457a869 [HIP] Fix device stub name
HIP emits a device stub function for each kernel in host code.

The HIP debugger requires device stub function to have a different unmangled name as the kernel.

Currently the name of the device stub function is the mangled name with a postfix .stub. However,
this does not work with the HIP debugger since the unmangled name is the same as the kernel.

This patch adds prefix __device__stub__ to the unmangled name of the device stub before mangling,
therefore the device stub function has a valid mangled name which is different than the device kernel
name. The device side kernel name is kept unchanged. kernels with extern "C" also gets the prefix added
to the corresponding device stub function.

Differential Revision: https://reviews.llvm.org/D68578
2020-03-09 16:40:05 -04:00
Benjamin Kramer adcd026838 Make llvm::StringRef to std::string conversions explicit.
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.
2020-01-28 23:25:25 +01:00
Guillaume Chatelet c79099e0f4 [Alignment][Clang][NFC] Add CharUnits::getAsAlign
Summary:
This is a prerequisite to removing `llvm::GlobalObject::setAlignment(unsigned)`.
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: jholewinski, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68274

llvm-svn: 373592
2019-10-03 13:00:29 +00:00
Yaxun Liu 1282889347 [HIP] Support new kernel launching API
Differential Revision: https://reviews.llvm.org/D67947

llvm-svn: 372773
2019-09-24 19:16:40 +00:00
Kadir Cetinkaya 3c9391aad9 [clang][CodeGen] Remove std::move on temporary
llvm-svn: 363563
2019-06-17 14:23:06 +00:00
Michael Liao e40f879eb2 [HIP] Add the interface deriving the stub name of device kernels.
Summary:
- Revise the interface to derive the stub name and simplify the
  assertion of it.

Reviewers: yaxunl, tra

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D63335

llvm-svn: 363553
2019-06-17 12:51:36 +00:00
Aaron Enye Shi 6d37f326fc [HIP-Clang] Fat binary should not be produced for non GPU code
clang-format the changes to CUDA and HIP fat binary.

Reviewers: yaxunl, tra

Differential Revision: https://reviews.llvm.org/D60141

llvm-svn: 357532
2019-04-02 21:54:41 +00:00
Aaron Enye Shi 8129521318 [HIP-Clang] Fat binary should not be produced for non GPU code 2
Also for CUDA, we need to disable producing these fat binary functions when there is no GPU code.

Reviewers: yaxunl, tra

Differential Revision: https://reviews.llvm.org/D60141

llvm-svn: 357526
2019-04-02 20:49:41 +00:00
Aaron Enye Shi 13d8e92940 [HIP-Clang] Fat binary should not be produced for non GPU code
Skip producing the fat binary functions for HIP when no device code is present.

Reviewers: yaxunl

Differential Review: https://reviews.llvm.org/D60141

llvm-svn: 357520
2019-04-02 20:10:18 +00:00
Yaxun Liu e739ac0e25 [HIP] change kernel stub name
Add .stub to kernel stub function name so that it is different from kernel
name in device code. This is necessary to let debugger find correct symbol
for kernel.

Differential Revision: https://reviews.llvm.org/D58518

llvm-svn: 354948
2019-02-27 02:02:52 +00:00
Yaxun Liu 00ebc0cb92 revert r354615: [HIP] change kernel stub name
It caused regressions.

Differential Revision: https://reviews.llvm.org/D58518

llvm-svn: 354651
2019-02-22 04:20:12 +00:00
Yaxun Liu 8d7cf0e2d4 [HIP] change kernel stub name
Add .stub to kernel stub function name so that it is different from kernel
name in device code. This is necessary to let debugger find correct symbol
for kernel

Differential Revision: https://reviews.llvm.org/D58518

llvm-svn: 354615
2019-02-21 20:12:16 +00:00
Yaxun Liu c18e9ecd4f [CUDA][HIP] Use device side kernel and variable names when registering them
__hipRegisterFunction and __hipRegisterVar need to accept device side kernel and variable names
so that HIP runtime can associate kernel stub functions in host code with kernel symbols in fat binaries,
and associate shadow variables in host code with device variables in fat binaries.

Currently, clang assumes kernel functions and device variables have the same name as the kernel
stub functions and shadow variables. However, when host is compiled in windows with MSVC C++
ABI and device is compiled with Itanium C++ ABI (e.g. AMDGPU), kernels and device symbols in fat
binary are mangled differently than host.

This patch gets the device side kernel and variable name by mangling them in the mangle context
of aux target.

Differential Revision: https://reviews.llvm.org/D58163

llvm-svn: 354004
2019-02-14 02:00:09 +00:00
Artem Belevich 4071763bb8 Basic CUDA-10 support.
Differential Revision: https://reviews.llvm.org/D57771

llvm-svn: 353232
2019-02-05 22:38:58 +00:00
James Y Knight 9871db064d [opaque pointer types] Pass function types for runtime function calls.
Emit{Nounwind,}RuntimeCall{,OrInvoke} have been modified to take a
FunctionCallee as an argument, and CreateRuntimeFunction has been
modified to return a FunctionCallee. All callers have been updated.

Additionally, CreateBuiltinFunction is removed, as it was redundant
with CreateRuntimeFunction after some previous changes.

Differential Revision: https://reviews.llvm.org/D57668

llvm-svn: 353184
2019-02-05 16:42:33 +00:00
James Y Knight 916db651c8 Remove redundant FunctionDecl argument from a couple functions.
This argument was added in r254554 in order to support the
pass_object_size attribute. However, in r296076, the attribute's
presence is now also represented in FunctionProtoType's
ExtParameterInfo, and thus it's unnecessary to pass along a separate
FunctionDecl.

The functions modified are:
 RequiredArgs::forPrototype{,Plus}, and
 CodeGenTypes::ConvertFunctionType.

After this, it's also (again) unnecessary to have a separate
ConvertFunctionType function ConvertType, so convert callers back to
the latter, leaving the former as an internal helper function.

llvm-svn: 352946
2019-02-02 01:48:23 +00:00
Artem Belevich c62214da3d [CUDA] add support for the new kernel launch API in CUDA-9.2+.
Instead of calling CUDA runtime to arrange function arguments,
the new API constructs arguments in a local array and the kernels
are launched with __cudaLaunchKernel().

The old API has been deprecated and is expected to go away
in the next CUDA release.

Differential Revision: https://reviews.llvm.org/D57488

llvm-svn: 352799
2019-01-31 21:34:03 +00:00
James Y Knight 3933addd30 Cleanup: replace uses of CallSite with CallBase.
llvm-svn: 352595
2019-01-30 02:54:28 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Artem Belevich 93552b39c9 [CUDA] Use all 64 bits of GUID in __nv_module_id
getGUID() returns an uint64_t and "%x" only prints 32 bits of it.
Use PRIx64 format string to print all 64 bits.

Differential Revision: https://reviews.llvm.org/D52938

llvm-svn: 343875
2018-10-05 18:39:58 +00:00
Yaxun Liu 9767089d00 [HIP] Support early finalization of device code for -fno-gpu-rdc
This patch renames -f{no-}cuda-rdc to -f{no-}gpu-rdc and keeps the original
options as aliases. When -fgpu-rdc is off,
clang will assume the device code in each translation unit does not call
external functions except those in the device library, therefore it is possible
to compile the device code in each translation unit to self-contained kernels
and embed them in the host object, so that the host object behaves like
usual host object which can be linked by lld.

The benefits of this feature is: 1. allow users to create static libraries which
can be linked by host linker; 2. amortized device code linking time.

This patch modifies HIP action builder to insert actions for linking device
code and generating HIP fatbin, and pass HIP fatbin to host backend action.
It extracts code for constructing command for generating HIP fatbin as
a function so that it can be reused by early finalization. It also modifies
codegen of HIP host constructor functions to embed the device fatbin
when it is available.

Differential Revision: https://reviews.llvm.org/D52377

llvm-svn: 343611
2018-10-02 17:48:54 +00:00
Yaxun Liu 94ff57f5b1 [HIP] Make __hip_gpubin_handle hidden to avoid being merged across different shared libraries
Different shared libraries contain different fat binary, which is stored in a global variable
__hip_gpubin_handle. Since different compilation units share the same fat binary, this
variable has linkonce linkage. However, it should not be merged across different shared
libraries.

This patch set the visibility of the global variable to be hidden, which will make it invisible
in the shared library, therefore preventing it from being merged.

Differential Revision: https://reviews.llvm.org/D50596

llvm-svn: 340056
2018-08-17 17:47:31 +00:00