This PR aims to unify the map argument generation behavior across both the implicit capture (captured in a target region) and the explicit capture (process map), currently the varPtr field of the MapInfo for the same variable will be different depending on how it's captured. This PR tries to align that across the generations of MapInfoOp in the OpenMP lowering. Currently, I have opted to utilise the rawInput (input memref to a HLFIR DeclareInfoOp) as opposed to the addr field which includes more information. The side affect of this is that we have to deal with BoxTypes less often, which will result in simpler maps in these cases. The negative side affect of this is that we don't have access to the bounds information through the resulting value, however, I believe the bounds information we require in our case is still appropriately stored in the map bounds, and this seems to be the case from testing so far. The other fix is for cases where we end up with a BoxType argument into a function (certain assumed shape and sizes cases do this) that has no fir.ref wrapping it. As we need the Box to be a reference type to actually utilise the operation to access the base address stored inside and create the correct mappings we currently generate an intermediate allocation in these cases, and then store into it, and utilise this as the map argument, as opposed to the original. However, as we were not sharing the same intermediate allocation across all of the maps for a variable, this resulted in errors in certain cases when detatching/attatching the data e.g. via enter and exit. This PR adjusts this for cases Currently we only maintain tracking of all intermediate allocations for the current function scope, as opposed to module. Primarily as the only case I am aware of that this is required is in cases where we pass certain types of arguments to functions (so I opted to minimize the overhead of the pass for now). It could likely be extended to module scope if required if we find other cases where it's applicable and causing issues.
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