matrix multiplication speedup when the matrix elements are 0, 1 and -1
Per row of A you would perform 9 multiplication and six additions, which you could perform with 3 multiplications and 6 fused multiply-add instructions. Like
ResultX = ax * c00 + bx * c01 + cx * c02
ResultY = ax * c10 + bx * c11 + cx * c12
ResultZ = ax * c20 + bx * c21 + cx * c22

Use a switch for the 27 possible values of c00, c10 and c20. Then we need just the fma’s and even replace one of them with a plain multiplication in case one of these numbers is zero.