Returns a vector containing the results of performing a saturated multiply-sum operation using the given vectors.
Elemental function
The result is a vector of the same type as ARG3.
Assume that the elements of each vector are numbered beginning with 0. For each element n of the result vector, the value is obtained in the following way: For p = 2n to 2n+1, multiply element p of ARG1 by element p of ARG2. Add the sum of these products to element n of ARG3. All additions are performed using 32-bit saturated arithmetic.