By default, ATLAS will not use ARM32's SIMD vectorization (NEON), since
it is not IEEE-compliant. However, you can force its use by adding
the following flags to your configure command:
-Fa al -mfpu=neon -Si ieee 0
Note that NEON only supports single precision, so this will not change
accuracy or speed for double precision.
R. Clint Whaley