The Ada language has got Out and In/Out parameters for subprograms and gigi
builds a special structure return type to pass them back. The attached patch
improves the latter mechanism by promoting the mode of this structure return
type if it is passed in registers.
Tested on i586-suse-linux, applied on the mainline.
2011-07-24 Eric Botcazou <ebotca...@adacore.com>
* gcc-interface/decl.c (gnat_to_gnu_entity) <E_Subprogram_Type>: If the
subprogram has copy-in copy-out parameters, try to promote the mode of
the return type if it is passed in registers.
--
Eric Botcazou
Index: gcc-interface/decl.c
===================================================================
--- gcc-interface/decl.c (revision 176673)
+++ gcc-interface/decl.c (working copy)
@@ -4245,17 +4245,50 @@ gnat_to_gnu_entity (Entity_Id gnat_entit
}
}
- /* Do not compute record for out parameters if subprogram is
- stubbed since structures are incomplete for the back-end. */
- if (gnu_field_list && Convention (gnat_entity) != Convention_Stubbed)
- finish_record_type (gnu_return_type, nreverse (gnu_field_list),
- 0, debug_info_p);
-
- /* If we have a CICO list but it has only one entry, we convert
- this function into a function that simply returns that one
- object. */
- if (list_length (gnu_cico_list) == 1)
- gnu_return_type = TREE_TYPE (TREE_PURPOSE (gnu_cico_list));
+ if (gnu_cico_list)
+ {
+ /* If we have a CICO list but it has only one entry, we convert
+ this function into a function that returns this object. */
+ if (list_length (gnu_cico_list) == 1)
+ gnu_return_type = TREE_TYPE (TREE_PURPOSE (gnu_cico_list));
+
+ /* Do not finalize the return type if the subprogram is stubbed
+ since structures are incomplete for the back-end. */
+ else if (Convention (gnat_entity) != Convention_Stubbed)
+ {
+ finish_record_type (gnu_return_type, nreverse (gnu_field_list),
+ 0, false);
+
+ /* Try to promote the mode of the return type if it is passed
+ in registers, again to speed up accesses. */
+ if (TYPE_MODE (gnu_return_type) == BLKmode
+ && !targetm.calls.return_in_memory (gnu_return_type,
+ NULL_TREE))
+ {
+ unsigned int size
+ = TREE_INT_CST_LOW (TYPE_SIZE (gnu_return_type));
+ unsigned int i = BITS_PER_UNIT;
+ enum machine_mode mode;
+
+ while (i < size)
+ i <<= 1;
+ mode = mode_for_size (i, MODE_INT, 0);
+ if (mode != BLKmode)
+ {
+ SET_TYPE_MODE (gnu_return_type, mode);
+ TYPE_ALIGN (gnu_return_type)
+ = GET_MODE_ALIGNMENT (mode);
+ TYPE_SIZE (gnu_return_type)
+ = bitsize_int (GET_MODE_BITSIZE (mode));
+ TYPE_SIZE_UNIT (gnu_return_type)
+ = size_int (GET_MODE_SIZE (mode));
+ }
+ }
+
+ if (debug_info_p)
+ rest_of_record_type_compilation (gnu_return_type);
+ }
+ }
if (Has_Stdcall_Convention (gnat_entity))
prepend_one_attribute_to
