struct Result sum_custom() {
        int i;
        struct Result res;
        int16_t table[0xFFFF];
        int idx;

        gettimeofday(&res.time_start, NULL);
        res.sum = 0;
        for(i = -32767; i <=32767;i++){
                table[i & 0xFFFF] = i * VOL;
        }

        int sz = SIZE;
        for(i = 0; i < sz ; i++){
                idx = (unsigned short) data[i];
                res.sum += output[i] = table[idx];
                res.sum += output[i] = table[(unsigned short) data[i++]];
                res.sum += output[i] = table[(unsigned short) data[i++]];
                res.sum += output[i] = table[(unsigned short) data[i++]];
                res.sum += output[i] = table[(unsigned short) data[i++]];

                res.sum += table[data[i++] & 0xFFFF]
                        + table[data[i++] & 0xFFFF]
                        + table[data[i] & 0xFFFF];

        }

        gettimeofday(&res.time_end, NULL);
        return res;
}