llvm-project

db0f754c - [OpenMP] Remove 'libomptarget.devicertl.a' fatbinary and use static library (#126143)

[OpenMP] Remove 'libomptarget.devicertl.a' fatbinary and use static library (#126143) Summary: Currently, we build a single `libomptarget.devicertl.a` which is a fatbinary. It is a host object file that contains the embedded archive files for both the NVIDIA and AMDGPU targets. This was done primarily as a convenience due to naming conflicts. Now that the clang driver for the GPU targets can appropriate link via the per-target runtime-dir, we can just make two separate static libraries and remove the indirection. This patch creates two new static libraries that get installed into ``` /lib/amdgcn-amd-amdhsa/libomp.a /lib/nvptx64-nvidia-cuda/libomp.a ``` for AMDGPU and NVPTX respectively. The link job created by the linker wrapper now simply needs to do `-lomp` and it will search those directories and link those static libraries. This requires far less special handling. This patch is a precursor to changing the build system entirely to be a runtimes based one. Soon this target will be a standard `add_library` and done through the GPU runtime targets. NOTE that this actually does remove an additional optimization step. Previously we merged all of the files into a single bitcode object and forcibly internalized some definitions. This, instead, just treats them like a normal static library. This may possibly affect performance for some files, but I think it's better overall to use static library semantics because it allows us to have an 'include-what-you-use' relationship with the library. Performance testing will be required. If we really need the merged blob then we can simply pack that into a new static library.