 
         if (device_test)
         {
-            Stats d_stats;
+            Stats stats;
 
             for (uint32 genome_begin = 0; genome_begin < n_queries; genome_begin += queries_batch)
             {

        
            h_qgram_index = qgram_index;

            Stats h_stats;

            for (uint32 genome_begin = 0; genome_begin < n_queries; genome_begin += queries_batch)
            {

                    genome_len,
                    genome_begin,
                    d_genome,
                    stats );
            }

            log_visible(stderr, "  testing q-gram index... done\n");
            const float genome_ratio = float(genome_len)/float(stats.queries);
            log_info(stderr, "    sorted throughput: %7.2f K reads/s\n", 1.0e-3f * float(n_strings)  / (stats.sorted_time * genome_ratio) );
            log_info(stderr, "    sorted throughput: %7.3f M bases/s\n", 1.0e-6f * float(string_len) / (stats.sorted_time * genome_ratio) );
            log_info(stderr, "    filter throughput: %7.2f K reads/s\n", 1.0e-3f * float(n_strings)  / (stats.filter_time * genome_ratio) );
            log_info(stderr, "    filter throughput: %7.3f M bases/s\n", 1.0e-6f * float(string_len) / (stats.filter_time * genome_ratio) );
            log_info(stderr, "    merged throughput: %7.2f K reads/s\n", 1.0e-3f * float(n_strings)  / (stats.merge_time  * genome_ratio) );
            log_info(stderr, "    merged throughput: %7.3f M bases/s\n", 1.0e-6f * float(string_len) / (stats.merge_time  * genome_ratio) );
        }
        if (host_test)
        {
