A = A + alpha * x * y.T; A is M*N, x is M*1, Y is N*1, 0 < R < E <= M, 0 < S < L <= N blas SYR2; blocked version
(A, X, Y []float64, alpha float64, flags Flags, ldA, incX, incY, S, L, NB int)
source not stored for this graph (policy: none)
no outgoing calls