[__arm_]vqdmulltq[_s16]

Performs an element-wise integer multiplication of two single-width source operand elements. These are selected from either the top half (T variant) or bottom half (B variant) of double-width source vector register elements or the lower single-width portion of the general-purpose register. The product of the multiplication is doubled and saturated to produce a double-width product that is written back to the destination vector register.