
$$d=c+\sum _{i=1}^{n}{a}_{i}{b}_{i}\text{.}$$ 
(a)  If ${\mathbf{SW}}=\mathrm{.TRUE.}$, the products are accumulated in additional precision, and on exit the result is available either in basic precision, correctly rounded, or in additional precision. 
(b)  If ${\mathbf{SW}}=\mathrm{.FALSE.}$, the products are accumulated in basic precision, and the result is returned in basic precision. 
On entry,  ${\mathbf{ISTEPA}}\le 0$, 
or  ${\mathbf{ISTEPB}}\le 0$. 
On entry,  ${\mathbf{ISIZEA}}>\left({\mathbf{N}}1\right)\times {\mathbf{ISTEPA}}+1$, 
or  ${\mathbf{ISIZEB}}>\left({\mathbf{N}}1\right)\times {\mathbf{ISTEPB}}+1$. 
$$A=\left(\begin{array}{rrr}2& 3& 7\\ 2& 5& 3\\ 9& 1& 0\end{array}\right)\text{, \hspace{1em}}{\mathbf{B}}=\left(\begin{array}{r}8\\ 4\\ 2\end{array}\right)\text{.}$$ 