[nestorD]

The authors ends by noting that FMA would probably have improved the performances for the Rust code.

It is interesting to note that, whereas most ffast-math optimization will trade precision for reduced computing time, adding an FMA can only improve the precision of the output (and thus it is a safe optimization).

[gameswithgo]

pedantry: ffast-math does not always trade precision. It simply trades the results being the same as if they were not vectorized. A vectorized sum of floats for instance is more accurate, not less.