Lapack with Meson or CMake

A clean, modern FindLAPACK.cmake with verified compatibility across a wide range of compilers, operating systems and Lapack vendors. Optionally, uses PkgConfig in CMake to make finding Lapack / LapackE more robust.

CMake

Here is a brief listing of known working configurations:

Windows:

Compiler	Lapack
MSVC 15 2017	Intel MKL
PGI	Intel MKL

Linux:

Compiler	Lapack
gcc + gfortran	Netlib Lapack
gcc + gfortran	Intel MKL
gcc + gfortran	Atlas
gcc + gfortran	OpenBLAS
Clang + gfortran	Netlib Lapack
Clang + gfortran	Intel MKL
Clang + gfortran	Atlas
Clang + gfortran	OpenBLAS
Clang + Flang	Netlib Lapack
Clang + Flang	Intel MKL
Clang + Flang	Atlas
Clang + Flang	OpenBLAS

Example

This example is for SVD computation using LapackE from C.

For most non-MSVC compilers (e.g. GNU, PGI, Clang, etc.):

ctest -S setup.cmake -VV

If you have a Fortran compiler, a Fortran Lapack example will also be built and tested.

For MSVC compilers, only the C example is built, and requires Intel MKL:

cmake -G "Visual Studio 16 2019" -B build

cmake --build build

Meson

Lapack with Meson works with similar compiler configurations as CMake.

meson build

meson test -C build

to use MKL with Meson, do like

meson build -DMKL_ROOT=$MKLROOT  # linux

prereq

• Linux: apt install liblapacke-dev
• Mac: brew install lapack
• Windows: compile Lapack from source, or use Windows Subsystem for Linux.

Intel MKL

Intel MKL is automatically detected by if MKLROOT environment variable is set. This variable should be set BEFORE using CMake as proscribed by Intel for your operating system, typically by running mklvars script. Here I assume you've installed MKL as appropriate for the MKL directory structure.

The command used to activate Intel MKL for each Terminal / Command Prompt session is like:

• Linux: source ~/intel/mkl/bin/mklvars.sh intel64
• Mac: source ~/intel/mkl/bin/mklvars.sh intel64
• Windows: c:\"Program Files (x86)"\IntelSWTools\compilers_and_libraries\windows\mkl\bin\mklvars.bat intel64

You need to do this EVERY TIME you want to use MKL for the Terminal / Command Prompt, or run it automatically at startup. What we usually do is create a script in the home directory that simply runs that command when called.

To verify Intel MKL was used, run a program with MKL_VERBOSE=1 like:

• Mac / Linux: MKL_VERBOSE=1 ./build/svd_c

• Windows:

  set MKL_VERBOSE=1
  
  build\c_src\Debug\svd_c

Windows

• On Windows, MinGW is not supported with MKL at least through MKL 2019--you will get all kinds of errors.
• Windows CMake systems that don't want to use MSVC must in general include cmake -G "MinGW Makefiles" along with their other options. This is true for anything CMake is used for on Windows where Visual Studio is not wanted.