npcs             4020 gc/os_dep.c      int npcs, i;
npcs             4034 gc/os_dep.c      npcs = backtrace((void **)tmp_info, NFRAMES + IGNORE_FRAMES);
npcs             4035 gc/os_dep.c      BCOPY(tmp_info+IGNORE_FRAMES, info, (npcs - IGNORE_FRAMES) * sizeof(void *));
npcs             4036 gc/os_dep.c      for (i = npcs - IGNORE_FRAMES; i < NFRAMES; ++i) info[i].ci_pc = 0;