Function execute 

pub fn execute<A, B, C, D>(
    mat_a: &Matrix<A>,
    mat_b: &Matrix<B>,
    mat_c: &Matrix<C>,
    mat_d: &Matrix<D>,
)
where
    A: CubePrimitive,
    B: CubePrimitive,
    C: CubePrimitive,
    D: CubePrimitive,

Execute the matrix-multiply and accumulate operation on the given matrices.