1config BR2_PACKAGE_FFTW 2 bool "fftw" 3 select BR2_PACKAGE_FFTW_DOUBLE if !BR2_PACKAGE_FFTW_SINGLE \ 4 && !BR2_PACKAGE_FFTW_LONG_DOUBLE && !BR2_PACKAGE_FFTW_QUAD 5 help 6 Library for computing Fast Fourier Transforms. 7 8 This library computes Fast Fourier Transforms (FFT) in one 9 or more dimensions. It is extremely fast. This package 10 contains the shared library version of the fftw libraries in 11 double precision. 12 13 http://www.fftw.org 14 15if BR2_PACKAGE_FFTW 16 17source "package/fftw/fftw-single/Config.in" 18source "package/fftw/fftw-double/Config.in" 19source "package/fftw/fftw-long-double/Config.in" 20source "package/fftw/fftw-quad/Config.in" 21 22config BR2_PACKAGE_FFTW_FAST 23 bool "optimise for speed over accuracy" 24 help 25 Optimise for fast math functions, at the expense of accuracy. 26 27 Say 'y' if you need speed and can live with inaccuracies in 28 the results. Say 'n' (the default) if accuracy is of utmost 29 importance. 30 31 This basically uses gcc's -Ofast optimisation level, which in 32 turn is basically using gcc's -ffast-math. See the gcc manual 33 for what this means. 34 35endif 36