Artem Shinkarov authored Oct 21, 2012 and Artem Shinkarov committed Sep 13, 2013

Currently sel operation returns a scalar value, which is useless in case
of vector operations.  So _simd_sel_VxA_ (vec_len, idx, array)
acts similarly to sel, and accepts the same arguments, but it then
selects VEC_LEN elements starting from ARRAY[IDX].

Simd multiplication is very similar to the addition:
        _mul_SMxSM_ (vec_len, a, b)