FindFFTW

Find the FFTW library.

find_package(FFTW [REQUIRED] [QUIET]
             [COMPONENTS [single] [double] [long_double] [quad]])

By default, search for the double precision library fftw3

Search procedure

• FFTW_LIBRARIES and FFTW_INCLUDE_DIRS set by user

  • Nothing is searched and these variables are used instead

• Find MKL implementation via FFTW_ENABLE_MKL

  • If FFTW_ENABLE_MKL is explicitely set to ON, only MKL is considered

  • If FFTW_ENABLE_MKL is explictely set to OFF, MKL will not be considered

  • If FFTW_ENABLE_MKL is undefined, MKL is preferred unless ENABLE_MKL is explicitely set to OFF

  • Note: MKLROOT environment variable helps to detect MKL (See FindMKL.cmake)

• Find official FFTW impelementation

  • FFTW_ROOT variable / environment variable helps to detect FFTW

Components

If a different version or multiple versions of the library are required, these need to be specified as COMPONENTS. Note that double must be given explicitly if any COMPONENTS are specified.

The libraries corresponding to each of the COMPONENTS are:

single:

FFTW::fftw3f

double:

FFTW::fftw3

long_double:

FFTW::fftw3l

quad:

FFTW::fftw3q

Output variables

The following CMake variables are set on completion:

FFTW_FOUND:

true if FFTW is found on the system

FFTW_LIBRARIES:

full paths to requested FFTW libraries

FFTW_INCLUDE_DIRS:

FFTW include directory

Input variables

The following CMake variables are checked by the function:

FFTW_USE_STATIC_LIBS:

if true, only static libraries are found

FFTW_ROOT:

if set, this path is exclusively searched

FFTW_DIR:

equivalent to FFTW_ROOT (deprecated)

FFTW_PATH:

equivalent to FFTW_ROOT (deprecated)

FFTW_LIBRARIES:

User overriden FFTW libraries

FFTW_INCLUDE_DIRS:

User overriden FFTW includes directories

FFTW_ENABLE_MKL:

User requests use of MKL implementation