Lines Matching +full:openmp +full:- +full:build
4 Please do not hesitate to reach out to us on the `Discourse forums (Runtimes - OpenMP) <https://discourse.llvm.org/c/runtimes/openmp/35>`_ or join
11 -----
13 OpenMP in LLVM Technical Call
16 - Development updates on OpenMP (and OpenACC) in the LLVM Project, including Clang, optimization, and runtime work.
17 - Join `OpenMP in LLVM Technical Call <https://bluejeans.com/544112769//webrtc>`__.
18 - Time: Weekly call on every Wednesday 7:00 AM Pacific time.
19 - Meeting minutes are `here <https://docs.google.com/document/d/1Tz8WFN13n7yJ-SCE0Qjqf9LmjGUw0dWO9Ts1ss4YOdg/edit>`__.
20 - Status tracking `page <https://openmp.llvm.org/docs>`__.
23 OpenMP in Flang Technical Call
25 - Development updates on OpenMP and OpenACC in the Flang Project.
26 - Join `OpenMP in Flang Technical Call <https://bit.ly/39eQW3o>`_
27 - Time: Weekly call on every Thursdays 8:00 AM Pacific time.
28 - Meeting minutes are `here <https://docs.google.com/document/d/1yA-MeJf6RYY-ZXpdol0t7YoDoqtwAyBhFLr5thu5pFI>`__.
29 - Status tracking `page <https://docs.google.com/spreadsheets/d/1FvHPuSkGbl4mQZRAwCIndvQx9dQboffiD-xD0oqxgU0/edit#gid=0>`__.
35 ---
40 additions. Please post on the `Discourse forums (Runtimes - OpenMP) <https://discourse.llvm.org/c/runtimes/openmp/35>`__.
47 <https://llvm.org/docs/Contributing.html#how-to-submit-a-patch>`_.
52 Q: How to build an OpenMP GPU offload capable compiler?
59 .. code-block:: sh
61 $> cd llvm-project # The llvm-project checkout
62 $> mkdir build
63 $> cd build
64 $> cmake ../llvm -G Ninja \
65 -C ../offload/cmake/caches/Offload.cmake \ # The preset cache file
66 -DCMAKE_BUILD_TYPE=<Debug|Release> \ # Select build type
67 -DCMAKE_INSTALL_PREFIX=<PATH> \ # Where the libraries will live
70 To manually build an *effective* OpenMP offload capable compiler, only one extra CMake
71 option, ``LLVM_ENABLE_RUNTIMES="openmp;offload"``, is needed when building LLVM (Generic
74 are targeted by OpenMP are enabled. That can be done by adjusting the CMake
78 ``LLVM_ENABLE_RUNTIMES="openmp"`` OpenMP should not be enabled in
86 the compiler that builds the OpenMP device runtimes. The OpenMP host runtime
93 Q: How to build an OpenMP Nvidia offload capable compiler?
95 The Cuda SDK is required on the machine that will execute the openmp application.
97 If your build machine is not the target machine or automatic detection of the
100 - ``LIBOMPTARGET_DEVICE_ARCHITECTURES='sm_<xy>;...'`` where ``<xy>`` is the numeric
108 Q: How to build an OpenMP AMDGPU offload capable compiler?
111 required to build the LLVM toolchain and to execute the openmp application.
113 build the required subcomponents ROCt and ROCr from source.
115 The two components used are ROCT-Thunk-Interface, roct, and ROCR-Runtime, rocr.
118 OpenMP's perspective. Rocr is an implementation of `HSA
121 .. code-block:: text
123 SOURCE_DIR=same-as-llvm-source # e.g. the checkout of llvm-project, next to openmp
125 INSTALL_PREFIX=same-as-llvm-install
128 git clone git@github.com:RadeonOpenCompute/ROCT-Thunk-Interface.git -b roc-4.2.x \
129 --single-branch
130 git clone git@github.com:RadeonOpenCompute/ROCR-Runtime.git -b rocm-4.2.x \
131 --single-branch
134 cmake $SOURCE_DIR/ROCT-Thunk-Interface/ -DCMAKE_INSTALL_PREFIX=$INSTALL_PREFIX \
135 -DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS=OFF
139 cmake $SOURCE_DIR/ROCR-Runtime/src -DIMAGE_SUPPORT=OFF \
140 -DCMAKE_INSTALL_PREFIX=$INSTALL_PREFIX -DCMAKE_BUILD_TYPE=Release \
141 -DBUILD_SHARED_LIBS=ON
144 ``IMAGE_SUPPORT`` requires building rocr with clang and is not used by openmp.
146 Provided cmake's find_package can find the ROCR-Runtime package, LLVM will
147 build a tool ``bin/amdgpu-arch`` which will print a string like ``gfx906`` when
148 run if it recognises a GPU on the local system. LLVM will also build a shared
151 With those libraries installed, then LLVM build and installed, try:
153 .. code-block:: shell
155 clang -O2 -fopenmp -fopenmp-targets=amdgcn-amd-amdhsa example.c -o example && ./example
157 If your build machine is not the target machine or automatic detection of the
160 - ``LIBOMPTARGET_DEVICE_ARCHITECTURES='gfx<xyz>;...'`` where ``<xyz>`` is the
165 Q: What are the known limitations of OpenMP AMDGPU offload?
170 of the rocm device library, which will be searched for if linking with '-lm'.
183 - ``libomp.so`` (or similar), the host openmp runtime
184 - ``libomptarget.so``, the target-agnostic target offloading openmp runtime
185 - plugins loaded by libomptarget.so:
187 - ``libomptarget.rtl.amdgpu.so``
188 - ``libomptarget.rtl.cuda.so``
189 - ``libomptarget.rtl.x86_64.so``
190 - ``libomptarget.rtl.ve.so``
191 - and others
193 - dependencies of those plugins, e.g. cuda/rocr for nvptx/amdgpu
203 file <https://clang.llvm.org/docs/UsersManual.html#configuration-files>`__ to
205 as ``openmp.cfg`` next to your ``clang`` executable.
207 .. code-block:: text
209 # Library paths for OpenMP offloading.
210 -L '<CFGDIR>/../lib'
211 -Wl,-rpath='<CFGDIR>/../lib'
213 The plugins will try to find their dependencies in plugin-dependent fashion.
216 compiler build time. Otherwise it will attempt to dlopen ``libcuda.so``. It does
219 The amdgpu plugin is linked against ROCr if cmake found it at compiler build
220 time. Otherwise it will attempt to dlopen ``libhsa-runtime64.so``. It has rpath
221 set to ``$ORIGIN``, so installing ``libhsa-runtime64.so`` in the same directory is a
226 bitcode library, e.g. ``libomptarget-nvptx-sm_70.bc``.
236 flag, ``--libomptarget-nvptx-bc-path`` or ``--libomptarget-amdgcn-bc-path``. That
240 Q: Does OpenMP offloading support work in pre-packaged LLVM releases?
244 Q: Does OpenMP offloading support work in packages distributed as part of my OS?
251 Q: Does Clang support `<math.h>` and `<complex.h>` operations in OpenMP target on GPUs?
254 Yes, LLVM/Clang allows math functions and complex arithmetic inside of OpenMP
269 vendor, in an OpenMP begin/end declare variant. These functions will then be
273 `extensions to the OpenMP begin/end declare variant context selector
274 <https://clang.llvm.org/docs/AttributeReference.html#pragma-omp-declare-variant>`__
282 By using ``libomptarget.rtl.rpc.so`` and ``openmp-offloading-server``, it is
286 Q: Can I use dynamically linked libraries with OpenMP offloading?
293 Q: How to build an OpenMP offload capable compiler with an outdated host compiler?
296 Enabling the OpenMP runtime will perform a two-stage build for you.
297 If your host compiler is different from your system-wide compiler, you may need
299 ``--gcc-install-dir=/usr/lib/gcc/x86_64-linux-gnu/12`` so that clang will be
300 able to find the correct GCC toolchain in the second stage of the build.
302 For example, if your system-wide GCC installation is too old to build LLVM and
303 you would like to use a newer GCC, set ``--gcc-install-dir=``
306 Q: How can I include OpenMP offloading support in my CMake project?
309 Currently, there is an experimental CMake find module for OpenMP target
310 offloading provided by LLVM. It will attempt to find OpenMP target offloading
311 support for your compiler. The flags necessary for OpenMP target offloading will
317 ``find_package``. The module will be installed with your OpenMP installation by
318 default. Including OpenMP offloading support in an application should now only
321 .. code-block:: cmake
326 list(APPEND CMAKE_MODULE_PATH "${PATH_TO_OPENMP_INSTALL}/lib/cmake/openmp")
352 Q: Can OpenMP offloading compile for multiple architectures?
355 Since LLVM version 15.0, OpenMP offloading supports offloading to multiple
358 multiple sub-architectures for the same target. Additionally, static libraries
362 The architecture can either be specified manually using ``--offload-arch=``. If
363 ``--offload-arch=`` is present no ``-fopenmp-targets=`` flag is present then the
365 ``--fopenmp-targets=`` is present with no ``--offload-arch`` then the target
370 given that the necessary build tools are installed for both.
372 .. code-block:: shell
374 clang example.c -fopenmp --offload-arch=gfx90a --offload-arch=sm_80
379 .. code-block:: shell
381 clang example.c -fopenmp -fopenmp-targets=amdgcn-amd-amdhsa,nvptx64-nvidia-cuda \
382 -Xopenmp-target=amdgcn-amd-amdhsa --offload-arch=gfx90a \
383 -Xopenmp-target=nvptx64-nvidia-cuda --offload-arch=sm_80
388 .. code-block:: shell
390 clang example.c -fopenmp --offload-arch=gfx90a,gfx90a,sm_70,sm_80 -c
391 llvm-ar rcs libexample.a example.o
392 clang app.c -fopenmp --offload-arch=gfx90a -o app
394 The supported device images can be viewed using the ``--offloading`` option with
395 ``llvm-objdump``.
397 .. code-block:: shell
399 clang example.c -fopenmp --offload-arch=gfx90a --offload-arch=sm_80 -o example
400 llvm-objdump --offloading example
402 a.out: file format elf64-x86-64
407 triple amdgcn-amd-amdhsa
408 producer openmp
413 triple nvptx64-nvidia-cuda
414 producer openmp
416 Q: Can I link OpenMP offloading with CUDA or HIP?
419 OpenMP offloading files can currently be experimentally linked with CUDA and HIP
420 files. This will allow OpenMP to call a CUDA device function or vice-versa.
423 queried from OpenMP or CUDA.
426 for CUDA / HIP with ``--offload-new-driver`` and to link using
427 ``--offload-link``. Additionally, ``-fgpu-rdc`` must be used to create a
430 .. code-block:: shell
432 clang++ openmp.cpp -fopenmp --offload-arch=sm_80 -c
433 clang++ cuda.cu --offload-new-driver --offload-arch=sm_80 -fgpu-rdc -c
434 clang++ openmp.o cuda.o --offload-link -o app
445 Clang compiler and runtime libraries from the same build. Nevertheless, in order
446 to better support third-party libraries and toolchains that depend on existing
455 <https://libc.llvm.org/gpu/using.html#building-the-gpu-library>`_. Once built,
459 with OpenMP.
461 .. code-block:: shell
463 clang++ openmp.cpp -fopenmp --offload-arch=gfx90a -lcgpu
465 For more information on how this is implemented in LLVM/OpenMP's offloading
468 Q: What command line options can I use for OpenMP?
470 We recommend taking a look at the OpenMP
473 Q: Can I build the offloading runtimes without CUDA or HSA?
482 Q: Why is my build taking a long time?
484 When installing OpenMP and other LLVM components, the build time on multicore
485 systems can be significantly reduced with parallel build jobs. As suggested in
487 generator. This can be done with the CMake option ``cmake -G Ninja``. Afterward,
488 use ``ninja install`` and specify the number of parallel jobs with ``-j``. The build
489 time can also be reduced by setting the build type to ``Release`` with the
497 `LLVM Discourse <https://discourse.llvm.org/c/runtimes/openmp/>`__.