uchar4 doct product

I have two uchar4 struct : A and B.

Is there an instruction such that :
int res = dotProd(A,B )

or do I have to cast each field to int and then sum it :
int res = 0;
int ax = (int) a.x;
int bx = (int) b.x;
res += ax*bx;

thanks much

I think on a hardware level it’ll all be the same. CUDA registers are all scalar and 32 bit.