barrettMultiplier) >> barrettShift) return fieldReduceOnce(uint16(a - quotient*q)) } func fieldMul(a, b fieldElement) fieldElement { x := uint32(a) * uint32(b) return fieldReduce(x) } // fieldMulSub returns a * (b - c). This operation is fused to save a // fieldReduceOnce after the subtraction. func fieldMulSub(a, b, c fieldElement) fieldElement { x := uint32(a) * uint32(b-c+q) return fieldReduce(x) } // fieldAddMul returns a * b + c * d. This operation is fused to save a // fieldReduceOnce and a...