dead code in loop.c:insert_loop_mem

[Joern Rennecke <amylaar at cygnus dot co dot uk>]

  /* See if we've already seen this MEM.  */
  for (i = 0; i < loop_mems_idx; ++i)
    if (rtx_equal_p (m, loop_mems[i].mem))
      {
        if (GET_MODE (m) != GET_MODE (loop_mems[i].mem))
          /* The modes of the two memory accesses are different.  If
             this happens, something tricky is going on, and we just
             don't optimize accesses to this MEM.  */
          loop_mems[i].optimize = 0;

        return 0;
      }

rtx_equal_p will return zero if the modes don't match.