| commit | bdb17e2783b2aa9718c4e77a8fa2ecc3cde665b9 | [log] [tgz] |
|---|---|---|
| author | Tom Eccles <tom.eccles@arm.com> | Wed Mar 13 14:51:09 2024 +0000 |
| committer | Copybara-Service <copybara-worker@google.com> | Wed Mar 13 07:54:02 2024 -0700 |
| tree | 6a7f40c0bb598d66b093b5b4777df6b3981671e7 | |
| parent | 58c1e82048caead8088be65a368a0969237307ac [diff] |
[flang][OpenMP][OMPIRBuilder][mlir] Optionally pass reduction vars by ref (#84304) Previously reduction variables were always passed by value into and out of the initialization and combiner regions of the OpenMP reduction declare operation. This worked well for reductions of primitive types (and might perform better than passing by reference). But passing by reference will be useful for array and derived type reductions (e.g. to move allocation inside of the init region). Passing reductions by reference requires different LLVM-IR generation when lowering from MLIR because some of the loads/stores/allocations will now be moved inside of the init and combiner regions. This alternate code generation is requested using a new attribute to omp.wsloop and omp.parallel. Existing lowerings from mlir are unaffected (these will continue to use the by-value argument passing. Flang will continue to pass by-value argument passing for trivial types unless a (hidden) command line argument is supplied. Non-trivial types will always use the by-ref lowering. Array reductions are not ready yet (but are coming very soon). In the meantime, this is tested by forcing existing reductions to use by-ref. Commit series for by-ref OpenMP reductions 3/3 --------- Co-authored-by: Mats Petersson <mats.petersson@arm.com> GitOrigin-RevId: f46f5a01f4d5a7dcaf4a8fde5fc44eafdd9dbf27
Flang is a ground-up implementation of a Fortran front end written in modern C++. It started off as the f18 project (https://github.com/flang-compiler/f18) with an aim to replace the previous flang project (https://github.com/flang-compiler/flang) and address its various deficiencies. F18 was subsequently accepted into the LLVM project and rechristened as Flang.
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