Author: Shilei Tian Date: 2021-02-03T14:25:11-08:00 New Revision: 255f7398845a7cfb47aef53e40b68057ec56839e
URL: https://github.com/llvm/llvm-project/commit/255f7398845a7cfb47aef53e40b68057ec56839e DIFF: https://github.com/llvm/llvm-project/commit/255f7398845a7cfb47aef53e40b68057ec56839e.diff LOG: [OpenMP][NFC] Added release note for new `deviceRTLs` and hidden helper task Added release note for new `deviceRTLs` and hidden helper task for LLVM 12. Reviewed By: jdoerfert Differential Revision: https://reviews.llvm.org/D95584 (cherry picked from commit 7bc31018f71cac22b7060c49cefb6f3d0d2e2069) Added: Modified: openmp/docs/ReleaseNotes.rst Removed: ################################################################################ diff --git a/openmp/docs/ReleaseNotes.rst b/openmp/docs/ReleaseNotes.rst index 7f40d3c81510c..cb3464ad84f06 100644 --- a/openmp/docs/ReleaseNotes.rst +++ b/openmp/docs/ReleaseNotes.rst @@ -7,7 +7,7 @@ OpenMP 12.0.0 Release Notes These are in-progress notes for the upcoming LLVM 12.0.0 release. Release notes for previous releases can be found on `the Download Page <https://releases.llvm.org/download.html>`_. - + Introduction ============ @@ -44,3 +44,27 @@ Non-comprehensive list of changes in this release ``LIBOMPTARGET_INFO`` allows the user to request certain information from the ``libomptarget`` runtime using a 32-bit field. A full description of each environment variable is described :ref:`here <libopenmptarget_environment_vars>`. + +- ``target nowait`` was supported via hidden helper task, which is a task not + bound to any parallel region. A hidden helper team with a number of threads is + created when the first hidden helper task is encountered. The number of threads + can be configured via the environment variable + ``LIBOMP_NUM_HIDDEN_HELPER_THREADS``. By default it is 8. If + ``LIBOMP_NUM_HIDDEN_HELPER_THREADS=0``, hidden helper task is disabled and + falls back to a regular OpenMP task. It can also be disabled by setting the + environment variable ``LIBOMP_USE_HIDDEN_HELPER_TASK=OFF``. + +- ``deviceRTLs`` for NVPTX platform is CUDA free now. It is generally OpenMP code. + Target dependent parts are implemented with Clang/LLVM/NVVM intrinsics. CUDA + SDK is also dropped as a dependence to build the device runtime, which means + device runtime can also be built on a CUDA free system. However, it is + disabled by default. Set the CMake variable + ``LIBOMPTARGET_BUILD_NVPTX_BCLIB=ON`` to enable the build of NVPTX device + runtime on a CUDA free system. ``gcc-multilib`` and ``g++-multilib`` are + required. If CUDA is found, the device runtime will be built by default. + + - Static NVPTX device runtime library (``libomptarget-nvptx.a``) was dropped. + A bitcode library is required to build an OpenMP program. If the library is + not found in the default path or any of the paths defined by ``LIBRARY_PATH``, + an error will be raised. User can also specify the path to the bitcode device + library via ``--libomptarget-nvptx-bc-path=``. _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
