llvm-project.git/offload/DeviceRTL/src/Stub.cpp, branch main Unnamed repository; edit this file 'description' to name the repository. [OpenMP] Change build of OpenMP device runtime to be a separate runtime (#136729) 2025-09-08T12:51:52+00:00 Joseph Huber huberjn@outlook.com 2025-09-08T12:51:52+00:00 be6f110bc08fd5fb622485b50e30619936acc124 Summary: Currently we build the OpenMP device runtime as part of the `offload/` project. This is problematic because it has several restrictions when compared to the normal offloading runtime. It can only be built with an up-to-date clang and we need to set the target appropriately. Currently we hack around this by creating the compiler invocation manually, but this patch moves it into a separate runtimes build. This follows the same build we use for libc, libc++, compiler-rt, and flang-rt. This also moves it from `offload/` into `openmp/` because it is still the `openmp/` runtime and I feel it is more appropriate. We do want a generic `offload/` library at some point, but it would be trivial to then add that as a separate library now that we have the infrastructure that makes adding these new libraries trivial. This most importantly will require that users update their build configs, mostly adding the following lines at a minimum. I was debating whether or not I should 'auto-upgrade' this, but I just went with a warning. ``` -DLLVM_RUNTIME_TARGETS='default;amdgcn-amd-amdhsa;nvptx64-nvidia-cuda' \ -DRUNTIMES_nvptx64-nvidia-cuda_LLVM_ENABLE_RUNTIMES=openmp \ -DRUNTIMES_amdgcn-amd-amdhsa_LLVM_ENABLE_RUNTIMES=openmp \ ``` This also changed where the `.bc` version of the library lives, but it's still created. 
Summary:
Currently we build the OpenMP device runtime as part of the `offload/`
project. This is problematic because it has several restrictions when
compared to the normal offloading runtime. It can only be built with an
up-to-date clang and we need to set the target appropriately. Currently
we hack around this by creating the compiler invocation manually, but
this patch moves it into a separate runtimes build.

This follows the same build we use for libc, libc++, compiler-rt, and
flang-rt. This also moves it from `offload/` into `openmp/` because it
is still the `openmp/` runtime and I feel it is more appropriate. We do
want a generic `offload/` library at some point, but it would be trivial
to then add that as a separate library now that we have the
infrastructure that makes adding these new libraries trivial.

This most importantly will require that users update their build
configs, mostly adding the following lines at a minimum. I was debating
whether or not I should 'auto-upgrade' this, but I just went with a
warning.

```
    -DLLVM_RUNTIME_TARGETS='default;amdgcn-amd-amdhsa;nvptx64-nvidia-cuda'     \
    -DRUNTIMES_nvptx64-nvidia-cuda_LLVM_ENABLE_RUNTIMES=openmp \
    -DRUNTIMES_amdgcn-amd-amdhsa_LLVM_ENABLE_RUNTIMES=openmp \
```

This also changed where the `.bc` version of the library lives, but it's
still created.
 [Offload] Move `/openmp/libomptarget` to `/offload` (#75125) 2024-04-22T16:51:33+00:00 Johannes Doerfert johannes@jdoerfert.de 2024-04-22T16:51:33+00:00 330d8983d25d08580fc1642fea48b2473f47a9da 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> 
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>