Fix ICE on loop over constant vector at -O

[Eric Botcazou]

This is an internal error in for_each_index at -O:

+===========================GNAT BUG DETECTED==============================+
| 4.8.0 20121208 (experimental) [trunk revision 194319] (x86_64-suse-linux) 
GCC error:|
| in for_each_index, at tree-ssa-loop-im.c:324                             |
| Error detected around vect9.adb:45:1|

The callback is invoked on a vector CONST_DECL and stops.  That's an unusual 
situation (the CONST_DECL is wrapped up in a VIEW_CONVERT_EXPR to array type) 
but IMO there is no reason to accept other DECLs and stop on CONST_DECLs.

Tested on x86_64-suse-linux, applied on the mainline as obvious.


2012-12-08  Eric Botcazou  <ebotca...@adacore.com>

        * tree-ssa-loop-im.c (for_each_index) <CONST_DECL>: New case.


2012-12-08  Eric Botcazou  <ebotca...@adacore.com>

        * gnat.dg/vect9.ad[sb]: New test.
        * gnat.dg/vect9_pkg.ads: New helper.


-- 
Eric Botcazou
Index: tree-ssa-loop-im.c
===================================================================
--- tree-ssa-loop-im.c	(revision 194319)
+++ tree-ssa-loop-im.c	(working copy)
@@ -291,6 +291,7 @@ for_each_index (tree *addr_p, bool (*cbc
 
 	case VAR_DECL:
 	case PARM_DECL:
+	case CONST_DECL:
 	case STRING_CST:
 	case RESULT_DECL:
 	case VECTOR_CST:
-- { dg-do compile }
-- { dg-options "-O" }

package body Vect9 is

   function Cmove
     (X        : in Unit;
      Y        : in Unit;
      If_True  : in Unit;
      If_False : in Unit)
      return     Unit
   is
      Res : Unit;
   begin
        for P in Unit'Range loop
         if X (P) >= Y (P) then
            Res (P) := If_True (P);
         else
            Res (P) := If_False (P);
         end if;
      end loop;

      return Res;
   end;
   pragma Inline_Always (Cmove);

   procedure Proc
     (This : in Rec;
      CV   : in Unit_Vector;
      Data : in out Unit_Vector)
   is
   begin
      for Index in Data'Range loop
         Data (Index) := Mul (Zero_Unit, Zero_Unit);
         declare
            Addend : constant Unit
              := Cmove (CV (Index), Zero_Unit, Zero_Unit, Zero_Unit) ;
         begin
            Data (Index) := Data(Index) + Addend;
         end;
         This.Data (Index) := Data (Index);
      end loop;
   end;

end Vect9;
with Vect9_Pkg; use Vect9_Pkg;

package Vect9 is

   type Rec is record
      Data : Vector_Access;
   end record;

   procedure Proc
     (This : in Rec;
      CV   : in Unit_Vector;
      Data : in out Unit_Vector);

end Vect9;
package Vect9_Pkg is

   type Unit is array (1 .. 4) of Float;
   for Unit'Alignment use 32;
   pragma Machine_Attribute (Unit, "vector_type");
   pragma Machine_Attribute (Unit, "may_alias");

   Zero_Unit : constant Unit := (others => 0.0);

   function Mul (X : in Unit; Y : in Unit) return Unit;
   function "+"(Left, Right : Unit) return Unit;
   function "*"(Left, Right : Unit) return Unit;

   type Unit_Vector is array (Positive range <>) of Unit;
   type Vector_Access is access all Unit_Vector;

end Vect9_Pkg;