Accelerate LAPACKE

Unfortunately, Apple's Accelerate framework doesn't provide the LAPACKE C-interface library. Since MacOS 13.3 Ventura, the BLAS/LAPACK interface provided by Accelerate is recent enough to support the LAPACKE library.

This project uses Accelerate LAPACK to build the LAPACKE library against the Accelerate NEWLAPACK interface. More info on BLAS/LAPACK in Accelerate can be found there, too.

• How to compile
  • Prerequisites
  • Workflow with CMake
    • CMake v4 compatibility
  • Using LAPACKE in another project

How to compile

It is recommended to use the Apple System C Compiler /usr/bin/cc. You can also use a more recent Clang compiler provided by Homebrew or MacPorts. If you have other compilers installed on your system, make sure CMake finds the correct one. Otherwise, help CMake by setting the environment variable $ export CC=/usr/bin/cc in your terminal window.

It is also recommended to use at least CMake v3.25 with presets, but the CMake script also works down to CMake v3.12, if you set the required variables on the command line.

Prerequisites

Obviously, your operating system must be Mac OS X >=v13.3 Ventura with XCode installed. Additionally, you'll need the following software (easily obtainable via Homebrew or MacPorts):

• CMake
• Fortran compiler (e. g. gfortran contained in the gcc package) to make it through the Reference LAPACK configure script

Workflow with CMake

Use the accelerate-lapacke32 preset (or the accelerate-lapacke64 preset for the ILP64 interface) with CMake:

$ cmake --workflow --preset accelerate-lapacke32

This will configure LAPACKE to be installed in your ~/.local directory by default. If you prefer a different install location (e. g. /opt/custom), you can change it using a CMakeUserPresets.json file, for which a template file is provided:

$ cmake --workflow --preset user-accelerate-lapacke32

I wouldn't recommend installing to /usr/local (used by Homebrew on Intel Macs) or /opt/local (used by MacPorts).

Analyzing the resulting .dylib with otool, you can see:

$ otool -L ./build/32/_deps/reference-lapack-build/lib/liblapacke.dylib
./build/32/_deps/reference-lapack-build/lib/liblapacke.dylib:
    @rpath/liblapacke.3.dylib (compatibility version 3.0.0, current version 3.11.0)
    /System/Library/Frameworks/Accelerate.framework/Versions/A/Accelerate (compatibility version 1.0.0, current version 4.0.0)
    /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1351.0.0)

Only the Accelerate framework and the System library are linked into the .dylib. No libgfortran or other libraries are needed.

CMake v4 compatibility

To build the project with CMake v4 or higher, you must explicitly provide the CMAKE_OSX_SYSROOT variable in your CMakeUserPresets.json. Both the user-accelerate-lapacke32 and user-accelerate-lapacke64 presets should additionally have the cache variable "CMAKE_OSX_SYSROOT": "macosx". This is not included by default.

Using LAPACKE in another project

You can use your self-compiled LAPACKE library in other projects by importing the CMake package in the other project's CMakeLists.txt file:

find_package(LAPACKE CONFIG)

or

find_package(LAPACKE64 CONFIG)

and providing the above install location via the CMAKE_PREFIX_PATH variable from the command line:

$ cmake -S . -B ./build -D "CMAKE_PREFIX_PATH=~/.local"

This makes the imported lapacke/lapacke64 shared library target available in the other project's CMakeLists.txt.