Installing OpenBlas on Windows¶

These instructions largely derive from Installing OpenBLAS using Conda.

Install 64bit Miniconda3 with Python-2.7. It should be easily found in your preferred search engine's results. The current link is https://docs.conda.io/en/latest/miniconda.html. Install options:

• All users.
• Do not add Anaconda to the system path variable.
• Do not register Python as the system Python 2.7.

Open the "Anaconda Command Prompt", which should be available in the start menu, with administrative privileges. Execute

conda update -n base conda
conda config --add channels conda-forge
conda install -y cmake flang clangdev perl libflang
conda install -y -c isuruf kitware-ninja

Activate the 64-bit build environment with Visual Studio. E.g.,

"C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Auxiliary\Build\vcvars64.bat"

In a cygwin window, untar openblas into /winsame/builds-vs2017, and create the build directory

mkdir -p /winsame/builds-vs2017/openblas
cd /winsame/builds-vs2017/openblas
tar xf ~/svnpkgs/openblas-0.3.4.tar.xz

Back in the Anaconda prompt, move to the openblas area, create the build subdirectory, and set needed environment variables. E.g.,

D:
cd \winsame\builds-vs2017openblas\openblas-0.3.4
mkdir build
cd build
set "LIB=%CONDA_INSTALL_LOCN%\Library\lib;%LIB%"
set "CPATH=%CONDA_INSTALL_LOCN%\Library\include;%CPATH%

Configure, build, install shared openblas for installation into your contrib dir. E.g.,

cmake .. -G "Ninja" -DCMAKE_CXX_COMPILER=clang-cl -DCMAKE_C_COMPILER=clang-cl -DCMAKE_Fortran_COMPILER=flang -DBUILD_WITHOUT_LAPACK=no -DNOFORTRAN=0 -DDYNAMIC_ARCH=ON -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX:PATH=D:/winsame/contrib-vs2017/openblas-0.3.4-sersh
ninja clean
cmake --build . --config Release
ninja install/fast

Configure, build, install static openblas without autolinking of the shared runtime libraries for installation into your contrib dir. E.g.,

cmake .. -G "Ninja" -DCMAKE_CXX_COMPILER=clang-cl -DCMAKE_C_COMPILER=clang-cl -DCMAKE_Fortran_COMPILER=flang -DBUILD_WITHOUT_LAPACK=no -DNOFORTRAN=0 -DDYNAMIC_ARCH=ON -DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS=FALSE -DCMAKE_C_FLAGS_RELEASE:STRING="/O2 /Ob2 /D NDEBUG" -DCMAKE_CXX_FLAGS_RELEASE:STRING="/O2 /Ob2 /D NDEBUG" -DCMAKE_INSTALL_PREFIX:PATH=D:/winsame/contrib-vs2017/openblas-0.3.4-ser
ninja clean
cmake --build . --config Release
ninja install/fast