.  The
two FFTW packages are otherwise identical.  In FFTW 3.1, the fma and
non-fma versions were merged together into a single package, and the
<code>configure</code> script attempts to automatically guess which
version to use.   
<p>
The FFTW 3.1 <code>configure</code> script enables fma by default on PowerPC, Itanium, and PA-RISC, and disables it otherwise.  You can
force one or the other by using the <code>--enable-fma</code> or <code>--disable-fma</code> flag for <code>configure</code>.  
<p>
Definitel