Summary:
We provide an RPC server to manage calls initiated by the device to run
on the host. This is very useful for the built-in handling we have,
however there are cases where we would want to extend this
functionality.
Cases like Fortran or MPI would be useful, but we cannot put references
to these in the core offloading runtime. This way, we can provide this
as a library interface that registers custom handlers for whatever code
people want.
We finally got our buildbot added (to staging, at least) so we want to
start running L0 tests in CI.
We need `check-offload` to pass though, so XFAIL everything failing.
There's a couple `UNSUPPORTED` as well, those are for sporadic fails.
Also make set the `gpu` and `intelgpu` LIT variables when testing the
`spirv64-intel` triple.
We have no DeviceRTL yet so basically everything fails, but we manage to
get
```
Total Discovered Tests: 432
Unsupported : 169 (39.12%)
Passed : 67 (15.51%)
Expectedly Failed: 196 (45.37%)
```
We still don't build the level zero plugin by default and these tests
don't run unless the plugin was built, so this has no effect on most
builds.
---------
Signed-off-by: Nick Sarnie <nick.sarnie@intel.com>
Summary:
This was a lot of code that was only used for upstream LLVM builds of
AMDGPU offloading. We have a generic and fast `malloc` in `libc` now so
just use that. Simplifies code, can be added back if we start providing
alternate forms but I don't think there's a single use-case that would
justify it yet.
Summary:
Handling the RPC server requires running through list of jobs that the
device has requested to be done. Currently this is handled by the thread
that does the waiting for the kernel to finish. However, this is not
sound on NVIDIA architectures and only works for async launches in the
OpenMP model that uses helper threads.
However, we also don't want to have this thread doing work
unnnecessarily. For this reason we track the execution of kernels and
cause the thread to sleep via a condition variable (usually backed by
some kind of futex or other intelligent sleeping mechanism) so that the
thread will be idle while no kernels are running.
Summary:
This patch adds an RPC interface that lives directly in the OpenMP
device runtime. This allows OpenMP to implement custom opcodes.
Currently this is only providing the host call interface, which is the
raw version of reverse offloading. Previously this lived in `libc/` as
an extension which is not the correct place.
The interface here uses a weak symbol for the RPC client by the same
name that the `libc` interface uses. This means that it will defer to
the libc one if both are present so we don't need to set up multiple
instances.
The presense of this symbol is what controls whether or not we set up
the RPC server. Because this is an external symbol it normally won't be
optimized out, so there's a special pass in OpenMPOpt that deletes this
symbol if it is unused during linking. That means at `O0` the RPC server
will always be present now, but will be removed trivially if it's not
used at O1 and higher.
Summary:
The C library is intended to provide `__assert_fail`, so in the cases
that we have both we should defer to that. This means that if you build
the C library for GPUs you'll get the RPC based asser, and if not you'll
get the trap based one.
Many tests in the `offload` project have requirements defined by which
targets are not supported rather than which platforms are supported.
This patch aims to streamline the requirement definitions by adding four
new feature tags: `host`, `gpu`, `amdgpu`, and `nvidiagpu`.
In a nutshell, this moves our libomptarget code to populate the offload
subproject.
With this commit, users need to enable the new LLVM/Offload subproject
as a runtime in their cmake configuration.
No further changes are expected for downstream code.
Tests and other components still depend on OpenMP and have also not been
renamed. The results below are for a build in which OpenMP and Offload
are enabled runtimes. In addition to the pure `git mv`, we needed to
adjust some CMake files. Nothing is intended to change semantics.
```
ninja check-offload
```
Works with the X86 and AMDGPU offload tests
```
ninja check-openmp
```
Still works but doesn't build offload tests anymore.
```
ls install/lib
```
Shows all expected libraries, incl.
- `libomptarget.devicertl.a`
- `libomptarget-nvptx-sm_90.bc`
- `libomptarget.rtl.amdgpu.so` -> `libomptarget.rtl.amdgpu.so.18git`
- `libomptarget.so` -> `libomptarget.so.18git`
Fixes: https://github.com/llvm/llvm-project/issues/75124
---------
Co-authored-by: Saiyedul Islam <Saiyedul.Islam@amd.com>
