Class OpMul

examples/AutoResearch/AutoResearchSimd.h:1186–1188

    template<typename T> T operator()(T a, T b) const { return a - b; }
};
struct OpMul {
    template<typename T> T operator()(T a, T b) const { return a * b; }
};
// Helper: time 4-wide scalar s8x8 with a binary op
template <typename Op>
inline int64_t benchS8x8_4(int iters, Op op) {