[Bug ada/17548] New: -march=pentium4 slows down Ada code

["berndtrog at yahoo dot com" <gcc-bugzilla at gcc dot gnu dot org>]

$ gnatmake -f -O2 -march=pentium3 p4_ds_test
gcc -c -O2 -march=pentium3 p4_ds_test.adb
gnatbind -x p4_ds_test.ali
gnatlink p4_ds_test.ali -march=pentium3

$ time ./p4_ds_test

real    0m1.671s
user    0m1.580s
sys     0m0.070s



$ gnatmake -f -O2 -march=pentium4 p4_ds_test
gcc -c -O2 -march=pentium4 p4_ds_test.adb
gnatbind -x p4_ds_test.ali
gnatlink p4_ds_test.ali -march=pentium4

$ time ./p4_ds_test

real    0m4.395s
user    0m3.710s
sys     0m0.620s



-------------p4_ds_test.adb----------------------------------------
procedure P4_DS_Test
is
  type Enumeration is (Ident_1, Ident_2, Ident_3);

  type Record_Type (Discr: Enumeration := Ident_1);
  type Record_Pointer is access Record_Type;

  type Record_Type (Discr: Enumeration := Ident_1) is
     record
        Pointer_Comp:   Record_Pointer;
        case Discr is
           when Ident_1 =>  
              Enum_Comp : Enumeration;
           
	   when others =>
	      null;
        end case;
     end record;

  type Record_Type_x is
     record
        Pointer_Comp : Record_Pointer;
     end record;


  Pointer_Glob, Pointer_Glob_Next: Record_Pointer;

  procedure Proc_1 (Pointer_Par_In: in Record_Pointer)
   is 
      Next_Record : Record_Type
	renames Pointer_Par_In.Pointer_Comp.all;
   begin
      Next_Record := Pointer_Glob.all;
   end Proc_1;

begin

  Pointer_Glob_Next := new Record_Type;
  Pointer_Glob := new Record_Type
                        '(
                          Pointer_Comp   => Pointer_Glob_Next,
                          Discr          => Ident_1,
                          Enum_Comp      => Ident_3
                         );


  for Run_Index in 1 .. 20000000 Loop
    Proc_1 (Pointer_Glob);
  end loop; 

end P4_DS_Test;

-------------------------------------------------------------

gcc 3.4.2
hw: P4 512k Northwood

Note: 3.3.2 does not show this kind of behavior ...

-- 
           Summary: -march=pentium4 slows down Ada code
           Product: gcc
           Version: 3.4.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: ada
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: berndtrog at yahoo dot com
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17548