Function get_global_lut

csrc/cpu_ops.cpp:563–566

static std::mutex g_lut_mutex;

static const unsigned char* get_global_lut(const float* code) {
    std::lock_guard<std::mutex> lock(g_lut_mutex);
    return g_lut_cache.get_lut(code);
}

// Convert a normalized value in [-1, 1] to LUT index [0, 65535]
static inline uint16_t norm_to_lut_index(float val) {