Hint on including FFTW


I was having some problem with FFTW and ROOT. I’m working on my Mac Pro and the architecture that ROOT’s ./configure is picking up is 64 bit.

When I configure fftw 3.2.1 it does not pick up 64 bit, so it gives this linking error

g++ -g -dynamiclib -single_module -undefined dynamic_lookup -install_name @rpath/libFFTW.so -m64 -o lib/libFFTW.so math/fftw/src/TFFTComplex.o math/fftw/src/TFFTComplexReal.o math/fftw/src/TFFTReal.o math/fftw/src/TFFTRealComplex.o math/fftw/src/G__FFTW.o -ldl -L/usr/local/lib -lfftw3
ld warning: in /usr/local/lib/libfftw3.a, file is not of required architecture
==> lib/libFFTW.so done

It’s not so obvious that the error occurred b/c you see the ==> done at the end.

Anyways, a solution is to add to the FFTW configure command:

./configure CFLAGS="-m64" 

and one might also want to --enable-threads

We might want to include this on