[Bug c/21529] New: code size regression (+40%) with -Os from GCC-3.4.3 to 4.1

[etienne_lorrain at yahoo dot fr]

Compiling this code with -Os is more than 40 % bigger in size with GCC-4.1
compared to GCC-3.4.3.
See also thread: http://gcc.gnu.org/ml/gcc/2005-05/msg00532.html
>>>>
struct disk_interface_str {
    unsigned    nb_IDE_found;
    struct IDE_found_str {
        unsigned short  ideIOadr;
        unsigned short  ideIOctrladr;
        unsigned char   irq;
        unsigned char   bios_order;
        unsigned short  reserved;
        } *IDE_found;
    } DI;

void reorder_IDE_for_linux (void)
  {
  static const unsigned short idearray[] = {
        0x1F0, 0x170,
        0x1E8, 0x168,
        0x1E0, 0x160,
        };
  unsigned short cpt, order;

  for (order = 0; order < sizeof(idearray)/sizeof(idearray[0]); order++) {
      for (cpt = order + 1; cpt < DI.nb_IDE_found; cpt++)
          if (DI.IDE_found[cpt].ideIOadr == idearray[order])
              break;
      if (cpt < DI.nb_IDE_found) {
          struct IDE_found_str save = DI.IDE_found[cpt];
          unsigned short i;

          for (i = order; i < cpt; i++) {
              struct IDE_found_str tmp = DI.IDE_found[i];
              DI.IDE_found[i] = save;
              save = tmp;
              }
          DI.IDE_found[cpt] = save;
          }
      }
  }
<<<<

-- 
           Summary: code size regression (+40%) with -Os from GCC-3.4.3 to
                    4.1
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: etienne_lorrain at yahoo dot fr
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i486-pc-linux-gnu
  GCC host triplet: i486-pc-linux-gnu
GCC target triplet: i486-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21529