0aeaa2d93d
This PR seeks to expand/replace the Constant -> Instruction conversion that needs to occur inside of the OpenMP Target kernel generation to allow kernel argument replacement of uses within the kernel (cannot replace constant uses within constant expressions with non-constants). It does so by making use of the new-ish utility convertUsersOfConstantsToInstructions which is a much more expansive version of what the smaller "version" of the function I wrote does, effectively expanding uses of the input argument that are constant expressions into instructions so that we can replace with the appropriate kernel argument. Also alters convertUsersOfConstantsToInstructions to optionally restrict the replacement to a function and optionally leave dead constants alone, the latter is necessary when lowering from MLIR as we cannot be sure we can remove the constants at this stage, even if rewritten to instructions the ModuleTranslation may maintain links to the original constants and utilise them in further lowering steps (as when we're lowering the kernel, the module is still in the process of being lowered). This can result in unusual ICEs later. These dead constants can be tidied up later (and appear to be in subsequent lowering from checking with emit-llvm).
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.
The project is just starting and the design is still not ironed out. 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