Function cols_to_rows 

unsafe fn cols_to_rows([a, _, c, d]: &mut [__m128i; 4])

Available with target feature sse2 only.

The goal of this function is to transform the state words from:

[a3, a0, a1, a2]    [ 3,  0,  1,  2]
[b0, b1, b2, b3] == [ 4,  5,  6,  7]
[c1, c2, c3, c0]    [ 9, 10, 11,  8]
[d2, d3, d0, d1]    [14, 15, 12, 13]

to:

[a0, a1, a2, a3]    [ 0,  1,  2,  3]
[b0, b1, b2, b3] == [ 4,  5,  6,  7]
[c0, c1, c2, c3]    [ 8,  9, 10, 11]
[d0, d1, d2, d3]    [12, 13, 14, 15]

reversing the transformation of rows_to_cols.