84d511df8d
This is a branch off of https://github.com/llvm/llvm-project/pull/159856, in which consists of the runtime portion of the changes required to support indirect function and virtual function calls on an `omp target device` when the virtual class / indirect function is mapped to the device from the host. Key Changes - Introduced a new flag OMP_DECLARE_TARGET_INDIRECT_VTABLE to mark VTable registrations - Modified setupIndirectCallTable to support both VTable entries and indirect function pointers Details: The setupIndirectCallTable implementation was modified to support this registration type by retrieving the first address of the VTable and inferring the remaining data needed to build the indirect call table. Since the Vtables / Classes registered as indirect can be larger than 8 bytes, and the vtables may not be at the first address we either need to pass the size to __llvm_omp_indirect_call_lookup and have a check at each step of the binary search, or add multiple entries to the indirect table for each address registered. The latter was chosen. Commit: a00def3f20e166d4fb9328e6f0bc0742cd0afa31 is not a part of this PR and is handled / reviewed in: https://github.com/llvm/llvm-project/pull/159856, This is PR (2/3) Register Vtable PR (1/3): https://github.com/llvm/llvm-project/pull/159856, Codegen / _llvm_omp_indirect_call_lookup PR (3/3): https://github.com/llvm/llvm-project/pull/159857
The LLVM/Offload Subproject
The Offload subproject aims at providing tooling, runtimes, and APIs that allow users to execute code on accelerators or other "co-processors" that may or may not match the architecture of their "host". In the long run, all kinds of targets are in scope of this effort, including but not limited to: CPUs, GPUs, FPGAs, AI/ML accelerators, distributed resources, etc.
For OpenMP offload users, the project is ready and fully usable. The final API design is still under development. More content will show up here and on our webpage soon. In the meantime, people are encouraged to participate in our meetings (see below) and check our development board as well as the discussions on Discourse.
Meetings
Every second Wednesday, 7:00 - 8:00am PT, starting Jan 24, 2024. Alternates with the OpenMP in LLVM meeting. invite.ics Meeting Minutes and Agenda