[libomptarget][amdgcn] Build amdgcn devicertl as openmp
Change cmake to build as openmp and fix up some minor errors in the code.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D96533
Three minor changes in this patch:
- added UNLIKELY hint to few rarely executed branches;
- replaced couple of run time checks with debug assertions;
- moved check of presence of ittnotify tool from inside the function call.
Differential Revision: https://reviews.llvm.org/D95816
This patch enables omp_get_num_devices() and omp_get_initial_device() on
Windows by providing an alternative to dlsym on Windows, and proposes to
add a new libomptarget entry, __tgt_get_num_devices().
Differential Revision: https://reviews.llvm.org/D96182
This patch adds lower-bound and upper-bound to num_teams clause
according to OpenMP 5.1 specification. The initial number of teams
created is implementation defined, but it will be greater than or
equal to lower-bound and less than or equal to upper-bound. If
num_teams clause is not specified, the number of teams created is
implementation defined, but it will be greater or equal to 1.
Differential Revision: https://reviews.llvm.org/D95820
[libomptarget][amdgcn] Tolerate deadstripped device_state variable
The device_state variable may have been deadstripped. Similar to
device_environment, leave detection of missing but used symbol to loader.
Reviewed By: pdhaliwal
Differential Revision: https://reviews.llvm.org/D96330
[libomptarget][amdgcn] Tolerate deadstripped env variable
Discovered by Pushpinder. If the device_environment variable is unused
it can be deadstripped, in which case we should not abort due to it
missing. This change is safe in that a missing symbol which is actually
used can be reported by both linker and loader, and a missing unused
symbol is better deadstripped than left in the image.
Reviewed By: pdhaliwal
Differential Revision: https://reviews.llvm.org/D96329
Currently if there is not kernel argument, device synchronization will
be skipped. This can lead to two issues:
1. If there is any device error, it will not be captured;
2. The target region might end before the kernel is done, which is not spec
conformant.
The test added in this patch only runs on NVPTX platform, although it will not
be executed by Phab at all. It also requires `not` which is not available on most
systems.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D96067
The header `assert.h` needs to be included in order to use `assert` in the code.
When building NVPTX `deviceRTLs` on a CUDA free system, it requires headers from
`gcc-multilib`, which some systems don't have. This patch drops the use of
`assert` in common parts of `deviceRTLs`. In light of
`openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.h`, a code block
```
if (!cond)
__builtin_trap();
```
is being used. The builtin will be translated to `call void @llvm.trap()`, and
the corresponding PTX is `trap;`.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D95986
New affinity patch introduced legitimate sign-compare warnings that
clang doesn't report but GCC-10 does. This removes the warnings by
changing two variables types to unsigned.
Differential Revision: https://reviews.llvm.org/D95818
From https://bugs.llvm.org/show_bug.cgi?id=48973, we know that
`std::call_once(PM->RTLs.initFlag, &RTLsTy::LoadRTLs, PM->RTLs)` causes compile
time problems in libstdc++v3 5.3.1. This is because there was a defect in the
standard regarding the `call_once` (LWG 2442). This was fixed in libstdc++ soon
thereafter, but there are likely other standard libraries where this will fail.
By matching this function call with the other one, we fix this bug.
Differential Revision: https://reviews.llvm.org/D95769
FileCheck is required for OpenMP tests. The current detection can fail
if building OpenMP in-tree when user sets `LLVM_INSTALL_TOOLCHAIN_ONLY=ON`. As a
result, CMake will raise an error and the compilation will be broken. This patch
fixed the issue. When `FileCheck` is not a target, tests will just be skipped.
Reviewed By: jdoerfert, JonChesterfield
Differential Revision: https://reviews.llvm.org/D95689
Summary:
One option for the LIBOMPTARGET_INFO environment variable is to print the current status of the device's data mappings. These are a shared resource among threads so this needs to be protected when using multiple streams.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D95786
This patch refines the logic to choose compute capabilites via the
environment variable `LIBOMPTARGET_NVPTX_COMPUTE_CAPABILITIES`. It supports the
following values (all case insensitive):
- "all": Build `deviceRTLs` for all supported compute capabilites;
- "auto": Only build for the compute capability auto detected. Note that this
requires CUDA. If CUDA is not found, a CMake fatal error will be raised.
- "xx,yy" or "xx;yy": Build for compute capabilities `xx` and `yy`.
If `LIBOMPTARGET_NVPTX_COMPUTE_CAPABILITIES` is not set, it is equivalent to set
it to `all`.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D95687
This patch introduces a new environment variable to force monotonic
behavior for users that absolutely need it. This is in anticipation
of 5.0 change that uses non-monotonic behavior for dynamic scheduling
by default. Fixes for that and the actual switch are coming soon.
Differential Revision: https://reviews.llvm.org/D95263
Added release note for new `deviceRTLs` and hidden helper task for LLVM
12.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D95584
This patch created a new header file `target_interface.h` for declarations of all target dependent functions. All future targets can get things work by simply implementing all functions declared in the header and macros/data same as each `target_impl.h`.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D95300
In the past `-O1` was used when building NVPTX bitcode libraries. After
we switched to OpenMP, `-O1` was missing by mistake, leading to a huge performance
regression.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D95545
`[[clang::loader_uninitialized]]` is in macro `SHARED` but it doesn't
work for array like `parallelLevel`, so the variable will be zero initialized.
There is also a similar issue for `omptarget_nvptx_device_State` which is in
global address space. Its c'tor is also generated, which was not in the past when
building the `deviceRTLs` with CUDA. In this patch, we added the attribute to
the two variables explicitly.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D95550
Link error occurred when time profiling in libomp is enabled by default
because `libomp` is assumed to be a C library but the dependence on
`libLLVMSupport` for profiling is a C++ library. Currently the issue blocks all
OpenMP tests in Phabricator.
This patch set a new CMake option `OPENMP_ENABLE_LIBOMP_PROFILING` to
enable/disable the feature. By default it is disabled. Note that once time
profiling is enabled for `libomp`, it becomes a C++ library.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D95585
The remote offloading plugin's CMakeLists was trying to build if its
flag was enabled even if it didn't find gRPC/protobuf. The conditional
was wrong, it's fixed by this.
Differential Revision: https://reviews.llvm.org/D95574
D95466 dropped CUDA to build NVPTX deviceRTL and enabled it by default.
However, the building requires some libraries that are not available on non-CUDA
system by default, which could break the compilation. This patch disabled the
build by default. It can be enabled with `LIBOMPTARGET_BUILD_NVPTX_BCLIB=ON`.
Reviewed By: kparzysz
Differential Revision: https://reviews.llvm.org/D95556
When OMP_PLACES contains an invalid value, the warning informs the user
that the fallback is OMP_PLACES=threads, but the actual internal setting
is OMP_PLACES=cores and is detected as such with KMP_SETTINGS=1.
This patch informs the user that OMP_PLACES=cores is being used instead
of OMP_PLACES=threads.
Differential Revision: https://reviews.llvm.org/D95170
This patch adds the new algorithm for topology discovery using cpuid
leaf 1f. Only the new die level is detected and integrated into the
current affinity mechanisms including KMP_AFFINITY (granularity level
and compact/scatter algorithm), OMP_PLACES=dies, and KMP_HW_SUBSET.
Differential Revision: https://reviews.llvm.org/D95157
HWLOC 2.0 has numa nodes as separate children and are not in the main
parent/child topology tree anymore. This change takes this into
account. The main topology detection loop in the create_hwloc_map()
routine starts at a hardware thread within the initial affinity mask and
goes up the topology tree setting the socket/core/thread labels
correctly.
This change also introduces some of the more generic changes that the
future kmp_topology_t structure will take advantage of including a
generic ratio & count array (finding all ratios of topology layers like
threads/core cores/socket and finding all counts of each topology
layer), generic radix1 reduction step, generic uniformity check, and
generic printing of topology (en_US.txt)
Differential Revision: https://reviews.llvm.org/D95156
The check-libomptarget fails when building with LLVM_ENABLE_PROJECTS. This is because test configuration misses the path to libomp.so and libLLVMSupport.so when time profiling is enabled (both libraries have the same path when building). This patch add the path to the configuration.
Reviewed By: vzakhari
Differential Revision: https://reviews.llvm.org/D95376
Problem reported by Joseph Shen <joseph.smeng@gmail.com>.
The patch changes *(&<atomic-var>) to (&<atomic-var>)->load().
Differential Revision: https://reviews.llvm.org/D95485
With D94745, we no longer use CUDA SDK to compile `deviceRTLs`. Therefore,
many CMake code in the project is useless. This patch cleans up unnecessary code
and also drops the requirement to build NVPTX `deviceRTLs`. CUDA detection is
still being used however to determine whether we need to involve the tests. Auto
detection of compute capability is enabled by default and can be disabled by
setting CMake variable `LIBOMPTARGET_NVPTX_AUTODETECT_COMPUTE_CAPABILITY=OFF`.
If auto detection is enabled, and CUDA is also valid, it will only build the
bitcode library for the detected version; otherwise, all variants supported will
be generated. One drawback of this patch is, we now generate 96 variants of
bitcode library, and totally 1485 files to be built with a clean build on a
non-CUDA system. `LIBOMPTARGET_NVPTX_COMPUTE_CAPABILITIES=""` can be used to
disable building NVPTX `deviceRTLs`.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D95466
This patch sets the def-allocator-var ICV based on the environment variables
provided in OMP_ALLOCATOR. Previously, only allowed value for OMP_ALLOCATOR
was a predefined memory allocator. OpenMP 5.1 specification allows predefined
memory allocator, predefined mem space, or predefined mem space with traits in
OMP_ALLOCATOR. If an allocator can not be created using the provided environment
variables, the def-allocator-var is set to omp_default_mem_alloc.
Differential Revision: https://reviews.llvm.org/D94985
[libomptarget][cuda] Handle missing _v2 symbols gracefully
Follow on from D95367. Dlsym the _v2 symbols if present, otherwise use the
unsuffixed version. Builds a hashtable for the check, can revise for zero
heap allocations later if necessary.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D95415
Requiring 3.15 causes a build breakage, I'm sure none of the contents actually require
3.15 or above.
Differential Revision: https://reviews.llvm.org/D95474
[libomptarget][cuda] Gracefully handle missing cuda library
If using dynamic cuda, and it failed to load, it is not safe to call
cuGetErrorString.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D95412
[libomptarget][cuda] Only run tests when sure there is cuda available
Prior to D95155, building the cuda plugin implied cuda was installed locally.
With that change, every machine can build a cuda plugin, but they won't all have
cuda and/or an nvptx card installed locally.
This change enables the nvptx tests when either:
- libcuda is present
- the user has forced use of the dlopen stub
The default case when there is no cuda detected will no longer attempt to
run the tests on nvptx hardware, as was the case before D95155.
Reviewed By: jdoerfert, ronlieb
Differential Revision: https://reviews.llvm.org/D95467
This introduces a remote offloading plugin for libomptarget. This
implementation relies on gRPC and protobuf, so this library will only
build if both libraries are available on the system. The corresponding
server is compiled to `openmp-offloading-server`.
This is a large change, but the only way to split this up is into RTL/server
but I fear that could introduce an inconsistency amongst them.
Ideally, tests for this should be added to the current ones that but that is
problematic for at least one reason. Given that libomptarget registers plugin
on a first-come-first-serve basis, if we wanted to offload onto a local x86
through a different process, then we'd have to either re-order the plugin list
in `rtl.cpp` (which is what I did locally for testing) or find a better
solution for runtime plugin registration in libomptarget.
Differential Revision: https://reviews.llvm.org/D95314
In order to support remote execution, we need to be able to send the
target binary description to the remote host for registration (and
consequent deregistration). To support this, I added these two
optional new functions to the plugin API:
- `__tgt_rtl_register_lib`
- `__tgt_rtl_unregister_lib`
These functions will be called to properly manage the instance of
libomptarget running on the remote host.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D93293
From this patch (plus some landed patches), `deviceRTLs` is taken as a regular OpenMP program with just `declare target` regions. In this way, ideally, `deviceRTLs` can be written in OpenMP directly. No CUDA, no HIP anymore. (Well, AMD is still working on getting it work. For now AMDGCN still uses original way to compile) However, some target specific functions are still required, but they're no longer written in target specific language. For example, CUDA parts have all refined by replacing CUDA intrinsic and builtins with LLVM/Clang/NVVM intrinsics.
Here're a list of changes in this patch.
1. For NVPTX, `DEVICE` is defined empty in order to make the common parts still work with AMDGCN. Later once AMDGCN is also available, we will completely remove `DEVICE` or probably some other macros.
2. Shared variable is implemented with OpenMP allocator, which is defined in `allocator.h`. Again, this feature is not available on AMDGCN, so two macros are redefined properly.
3. CUDA header `cuda.h` is dropped in the source code. In order to deal with code difference in various CUDA versions, we build one bitcode library for each supported CUDA version. For each CUDA version, the highest PTX version it supports will be used, just as what we currently use for CUDA compilation.
4. Correspondingly, compiler driver is also updated to support CUDA version encoded in the name of bitcode library. Now the bitcode library for NVPTX is named as `libomptarget-nvptx-cuda_[cuda_version]-sm_[sm_number].bc`, such as `libomptarget-nvptx-cuda_80-sm_20.bc`.
With this change, there are also multiple features to be expected in the near future:
1. CUDA will be completely dropped when compiling OpenMP. By the time, we also build bitcode libraries for all supported SM, multiplied by all supported CUDA version.
2. Atomic operations used in `deviceRTLs` can be replaced by `omp atomic` if OpenMP 5.1 feature is fully supported. For now, the IR generated is totally wrong.
3. Target specific parts will be wrapped into `declare variant` with `isa` selector if it can work properly. No target specific macro is needed anymore.
4. (Maybe more...)
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D94745
Jon Chesterfield