Anybody have a decent FFT routine for that? AVR32 has a 32 bit multiply instruction, so I'm curious what could be achieved in the way of fixed-point DSP at something like 20-24 bits rather than the traditional 16 bit limitation of other devices. (16 bits in doesn't give you 16 bits of dynamic range out, as some scaling has to be done to provide headroom for intermediate results)
Of course just because a chip will do a 32 bit multiply in one instruction doesn't mean it's faster than another chip computing it with a few instructions - what really matters is clocks and caching or getting things statically placed in on-chip ram.