[Ada] Fix bogus error with packed array type on AVR

[Eric Botcazou <ebotcazou at adacore dot com>]

The testcase fails to compile for targets that define MAX_FIXED_MODE_SIZE to 
something smaller than 64, in particular the AVR.  It turns out that the 
check responsible for the problem is overzealous and can be relaxed.

Tested on i586-suse-linux, applied on the mainline.


2009-10-30  Eric Botcazou  <ebotcazou@adacore.com>

	* gcc-interface/utils.c (MAX_FIXED_MODE_SIZE): Delete.
	(create_field_decl): Update description.  In a packed record, round
	the size up to a byte boundary only if the field's type has BLKmode.
	* gcc-interface/gigi.h (create_field_decl): Update description.


2009-10-30  Eric Botcazou  <ebotcazou@adacore.com>

	* gnat.dg/specs/pack5.ads: New test.


-- 
Eric Botcazou

Index: gcc-interface/utils.c
===================================================================
--- gcc-interface/utils.c	(revision 153644)
+++ gcc-interface/utils.c	(working copy)
@@ -59,10 +59,6 @@
 #include "ada-tree.h"
 #include "gigi.h"
 
-#ifndef MAX_FIXED_MODE_SIZE
-#define MAX_FIXED_MODE_SIZE GET_MODE_BITSIZE (DImode)
-#endif
-
 #ifndef MAX_BITS_PER_WORD
 #define MAX_BITS_PER_WORD  BITS_PER_WORD
 #endif
@@ -1457,13 +1453,13 @@ aggregate_type_contains_array_p (tree ty
     }
 }
 
-/* Return a FIELD_DECL node.  FIELD_NAME the field name, FIELD_TYPE is its
-   type, and RECORD_TYPE is the type of the parent.  PACKED is nonzero if
-   this field is in a record type with a "pragma pack".  If SIZE is nonzero
-   it is the specified size for this field.  If POS is nonzero, it is the bit
-   position.  If ADDRESSABLE is nonzero, it means we are allowed to take
-   the address of this field for aliasing purposes. If it is negative, we
-   should not make a bitfield, which is used by make_aligning_type.   */
+/* Return a FIELD_DECL node.  FIELD_NAME is the field's name, FIELD_TYPE is
+   its type and RECORD_TYPE is the type of the enclosing record.  PACKED is
+   1 if the enclosing record is packed, -1 if it has Component_Alignment of
+   Storage_Unit.  If SIZE is nonzero, it is the specified size of the field.
+   If POS is nonzero, it is the bit position.  If ADDRESSABLE is nonzero, it
+   means we are allowed to take the address of the field; if it is negative,
+   we should not make a bitfield, which is used by make_aligning_type.  */
 
 tree
 create_field_decl (tree field_name, tree field_type, tree record_type,
@@ -1497,12 +1493,8 @@ create_field_decl (tree field_name, tree
   else if (packed == 1)
     {
       size = rm_size (field_type);
-
-      /* For a constant size larger than MAX_FIXED_MODE_SIZE, round up to
-         byte.  */
-      if (TREE_CODE (size) == INTEGER_CST
-          && compare_tree_int (size, MAX_FIXED_MODE_SIZE) > 0)
-        size = round_up (size, BITS_PER_UNIT);
+      if (TYPE_MODE (field_type) == BLKmode)
+	size = round_up (size, BITS_PER_UNIT);
     }
 
   /* If we may, according to ADDRESSABLE, make a bitfield if a size is
Index: gcc-interface/gigi.h
===================================================================
--- gcc-interface/gigi.h	(revision 153644)
+++ gcc-interface/gigi.h	(working copy)
@@ -643,12 +643,13 @@ extern void record_global_renaming_point
 /* Invalidate the global renaming pointers.  */
 extern void invalidate_global_renaming_pointers (void);
 
-/* Returns a FIELD_DECL node. FIELD_NAME the field name, FIELD_TYPE is its
-   type, and RECORD_TYPE is the type of the parent.  PACKED is nonzero if
-   this field is in a record type with a "pragma pack".  If SIZE is nonzero
-   it is the specified size for this field.  If POS is nonzero, it is the bit
-   position.  If ADDRESSABLE is nonzero, it means we are allowed to take
-   the address of this field for aliasing purposes.  */
+/* Return a FIELD_DECL node.  FIELD_NAME is the field's name, FIELD_TYPE is
+   its type and RECORD_TYPE is the type of the enclosing record.  PACKED is
+   1 if the enclosing record is packed, -1 if it has Component_Alignment of
+   Storage_Unit.  If SIZE is nonzero, it is the specified size of the field.
+   If POS is nonzero, it is the bit position.  If ADDRESSABLE is nonzero, it
+   means we are allowed to take the address of the field; if it is negative,
+   we should not make a bitfield, which is used by make_aligning_type.  */
 extern tree create_field_decl (tree field_name, tree field_type,
                                tree record_type, int packed, tree size,
                                tree pos, int addressable);

package Pack5 is

   type Small is range -32 .. 31;

   type Arr is array (Integer range <>) of Small;
   pragma Pack (Arr);

   type Rec is record
      Y: Arr (1 .. 10);
    end record;
   pragma Pack (Rec);

end Pack5;