make mul_array cache friendly
make mul_array cache friendly

dsroche/flint2,dsroche/flint2,wbhart/flint2,dsroche/flint2,dsroche/flint2,fredrik-johansson/flint2,fredrik-johansson/flint2,wbhart/flint2,wbhart/flint2,fredrik-johansson/flint2