This PR adds support for translation of the private clause on deferred target tasks - that is `omp.target` operations with the `nowait` clause. An offloading call for a deferred target-task is not blocking - the offloading (target-generating) host task continues its execution after issuing the offloading call. Therefore, the key problem we need to solve is to ensure that the data needed for private variables to be initialized in the target task persists even after the host task has completed. We do this in a new pass called `PrepareForOMPOffloadPrivatizationPass`. For a privatized variable that needs its host counterpart for initialization (such as the shape of the data from the descriptor when an allocatable is privatized or the value of the data when an allocatable is firstprivatized), - the pass allocates memory on the heap. - it then initializes this memory by using the `init` and `copy` (for firstprivate) regions of the corresponding `omp::PrivateClauseOp`. - Finally the memory allocated on the heap is freed using the `dealloc` region of the same `omp::PrivateClauseOp` instance. This step is not straightforward though, because we cannot simply free the memory that's going to be used by another thread without any synchronization. So, for deallocation, we create a `omp.task` after the `omp.target` and synchronize the two with a dummy dependency (using the `depend` clause). In this newly created `omp.task` we do the deallocation.
This PR shifts from using the LLVM OpenMP enumerator bit flags to an OpenMP dialect specific enumerator. This allows us to better represent map types that wouldn't be of interest to the LLVM backend and runtime in the dialect. Primarily things like ref_ptr/ref_ptee/ref_ptr_ptee/atach_none/attach_always/attach_auto which are of interest to the compiler for certrain transformations (primarily in the FIR transformation passes dealing with mapping), but the runtime has no need to know about them. It also means if another OpenMP implementation comes along they won't need to stick to the same bit flag system LLVM chose/do leg work to address it.
Use `DefaultUnreachable` from https://github.com/llvm/llvm-project/pull/161970.
Add the `omp.tile` loop transformations for the OpenMP dialect. Used for lowering a standalone `!$omp tile` in Flang.
This PR uses the VFS to create the OpenMP target entry instead of going straight to the real file system. This matches the behavior of other input files of the compiler.
Enable the generation of no-loop kernels for Fortran OpenMP code. target teams distribute parallel do pragmas can be promoted to no-loop kernels if the user adds the -fopenmp-assume-teams-oversubscription and -fopenmp-assume-threads-oversubscription flags. If the OpenMP kernel contains reduction or num_teams clauses, it is not promoted to no-loop mode. The global OpenMP device RTL oversubscription flags no longer force no-loop code generation for Fortran.
With declare mapper, the parent base entry was emitted as `TARGET_PARAM` only. The mapper received a map-type without `to/from`, causing components to degrade to `alloc`-only (no copies), breaking allocatable payload mapping. This PR preserves the map-type bits from the parent. This fixes #156466.
This is a follow-up to #150124. This PR makes it so that the `-fopenmp-host-ir-file-path` respects VFS overlays, like any other input file.
This patch enables tiling in flang. In MLIR tiling is handled by changing the the omp.loop_nest op to be able to represent both collapse and tiling, so the flang front-end will combine the nested constructs into a single MLIR op. The MLIR->LLVM-IR lowering of the LoopNestOp is enhanced to first do the tiling if present, then collapse.