Dot product computation circuits for handling quinary weights

Abstract

Some embodiments provide a neural network inference circuit (NNIC) for executing a neural network. The NNIC includes a set of circuits to compute a dot product of a set of inputs and a set of predefined weights. Each weight is one of a positive value, twice the positive value, the negation of the positive value, twice the negation of the positive value, and the value zero. The set of circuits includes an adder tree circuit to (i) receive at least a subset of the inputs, (ii) apply a negation factor to received inputs with negative corresponding weights, and (iii) add together the received inputs with the negation factors. The set of circuits includes, for each input of the subset of inputs, a circuit to configurably double the input when the weight corresponding to the input is either twice the positive value or twice the negation of the positive value.