fftw3: Installation on Unix
10.1 Installation on Unix
=========================
FFTW comes with a 'configure' program in the GNU style. Installation
can be as simple as:
./configure
make
make install
This will build the uniprocessor complex and real transform libraries
along with the test programs. (We recommend that you use GNU 'make' if
it is available; on some systems it is called 'gmake'.) The "'make
install'" command installs the fftw and rfftw libraries in standard
places, and typically requires root privileges (unless you specify a
different install directory with the '--prefix' flag to 'configure').
You can also type "'make check'" to put the FFTW test programs through
their paces. If you have problems during configuration or compilation,
you may want to run "'make distclean'" before trying again; this ensures
that you don't have any stale files left over from previous compilation
attempts.
The 'configure' script chooses the 'gcc' compiler by default, if it
is available; you can select some other compiler with:
./configure CC="<the name of your C compiler>"
The 'configure' script knows good 'CFLAGS' (C compiler flags) for a
few systems. If your system is not known, the 'configure' script will
print out a warning. In this case, you should re-configure FFTW with
the command
./configure CFLAGS="<write your CFLAGS here>"
and then compile as usual. If you do find an optimal set of 'CFLAGS'
for your system, please let us know what they are (along with the output
of 'config.guess') so that we can include them in future releases.
'configure' supports all the standard flags defined by the GNU Coding
Standards; see the 'INSTALL' file in FFTW or the GNU web page
(http://www.gnu.org/prep/standards/html_node/index.html). Note
especially '--help' to list all flags and '--enable-shared' to create
shared, rather than static, libraries. 'configure' also accepts a few
FFTW-specific flags, particularly:
* '--enable-float': Produces a single-precision version of FFTW
('float') instead of the default double-precision ('double').
Precision.
* '--enable-long-double': Produces a long-double precision version of
FFTW ('long double') instead of the default double-precision
('double'). The 'configure' script will halt with an error message
if 'long double' is the same size as 'double' on your
machine/compiler. Precision.
* '--enable-quad-precision': Produces a quadruple-precision version
of FFTW using the nonstandard '__float128' type provided by 'gcc'
4.6 or later on x86, x86-64, and Itanium architectures, instead of
the default double-precision ('double'). The 'configure' script
will halt with an error message if the compiler is not 'gcc'
version 4.6 or later or if 'gcc''s 'libquadmath' library is not
installed. Precision.
* '--enable-threads': Enables compilation and installation of the
FFTW threads library (Multi-threaded FFTW), which provides
a simple interface to parallel transforms for SMP systems. By
default, the threads routines are not compiled.
* '--enable-openmp': Like '--enable-threads', but using OpenMP
compiler directives in order to induce parallelism rather than
spawning its own threads directly, and installing an 'fftw3_omp'
library rather than an 'fftw3_threads' library (
Multi-threaded FFTW). You can use both '--enable-openmp' and
'--enable-threads' since they compile/install libraries with
different names. By default, the OpenMP routines are not compiled.
* '--with-combined-threads': By default, if '--enable-threads' is
used, the threads support is compiled into a separate library that
must be linked in addition to the main FFTW library. This is so
that users of the serial library do not need to link the system
threads libraries. If '--with-combined-threads' is specified,
however, then no separate threads library is created, and threads
are included in the main FFTW library. This is mainly useful under
Windows, where no system threads library is required and
inter-library dependencies are problematic.
* '--enable-mpi': Enables compilation and installation of the FFTW
MPI library (Distributed-memory FFTW with MPI), which
provides parallel transforms for distributed-memory systems with
MPI. (By default, the MPI routines are not compiled.) FFTW
MPI Installation.
* '--disable-fortran': Disables inclusion of legacy-Fortran wrapper
routines (Calling FFTW from Legacy Fortran) in the standard
FFTW libraries. These wrapper routines increase the library size
by only a negligible amount, so they are included by default as
long as the 'configure' script finds a Fortran compiler on your
system. (To specify a particular Fortran compiler foo, pass
'F77='foo to 'configure'.)
* '--with-g77-wrappers': By default, when Fortran wrappers are
included, the wrappers employ the linking conventions of the
Fortran compiler detected by the 'configure' script. If this
compiler is GNU 'g77', however, then _two_ versions of the wrappers
are included: one with 'g77''s idiosyncratic convention of
appending two underscores to identifiers, and one with the more
common convention of appending only a single underscore. This way,
the same FFTW library will work with both 'g77' and other Fortran
compilers, such as GNU 'gfortran'. However, the converse is not
true: if you configure with a different compiler, then the
'g77'-compatible wrappers are not included. By specifying
'--with-g77-wrappers', the 'g77'-compatible wrappers are included
in addition to wrappers for whatever Fortran compiler 'configure'
finds.
* '--with-slow-timer': Disables the use of hardware cycle counters,
and falls back on 'gettimeofday' or 'clock'. This greatly worsens
performance, and should generally not be used (unless you don't
have a cycle counter but still really want an optimized plan
regardless of the time). Cycle Counters.
* '--enable-sse' (single precision), '--enable-sse2' (single,
double), '--enable-avx' (single, double), '--enable-avx2' (single,
double), '--enable-avx512' (single, double),
'--enable-avx-128-fma', '--enable-kcvi' (single),
'--enable-altivec' (single), '--enable-vsx' (single, double),
'--enable-neon' (single, double on aarch64),
'--enable-generic-simd128', and '--enable-generic-simd256':
Enable various SIMD instruction sets. You need compiler that
supports the given SIMD extensions, but FFTW will try to detect at
runtime whether the CPU supports these extensions. That is, you
can compile with'--enable-avx' and the code will still run on a CPU
without AVX support.
- These options require a compiler supporting SIMD extensions,
and compiler support is always a bit flaky: see the FFTW FAQ
for a list of compiler versions that have problems compiling
FFTW.
- Because of the large variety of ARM processors and ABIs, FFTW
does not attempt to guess the correct 'gcc' flags for
generating NEON code. In general, you will have to provide
them on the command line. This command line is known to have
worked at least once:
./configure --with-slow-timer --host=arm-linux-gnueabi \
--enable-single --enable-neon \
"CC=arm-linux-gnueabi-gcc -march=armv7-a -mfloat-abi=softfp"
To force 'configure' to use a particular C compiler foo (instead of
the default, usually 'gcc'), pass 'CC='foo to the 'configure' script;
you may also need to set the flags via the variable 'CFLAGS' as
described above.
Info Catalog
fftw3: Installation and Customization
fftw3: Installation and Customization
fftw3: Installation on non-Unix systems