Some further information. The specgrm2 FFT program has 30 instructions
in the basic operation, including 4 multiplies, 2 adds, and 2 subtracts
on the actual data, which gives order 20 Gflops, or 100 Gips; the processor
clock cycle count will obviously be several times this.
This is for the Intel assembler version; a pure C one would probably
specgrm2 actually uses fixed point, not floating, arithmetic.