rs6000 va_arg patch

[David Edelsohn]

	When I started converting the AIX/Darwin va_arg function to
calculate the size with trees, I noticed that it is identical to
std_expand_bulitin_va_arg.  The only uniqueness is when to pad down.
Given that ia64.h references a variable local to the
std_expand_bulitin_va_arg where PAD_VARARGS_DOWN is invoked, I wasn't
going to be proud...

David


2002-03-13  David Edelsohn  <edelsohn@gnu.org>

        * config/rs6000/rs6000.h (PAD_VARARGS_DOWN): Define.
        * config/rs6000/rs6000.c (rs6000_va_arg): Use
        std_expand_builtin_va_arg if not ABI_V4.

Index: rs6000.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/config/rs6000/rs6000.c,v
retrieving revision 1.297
diff -c -p -r1.297 rs6000.c
*** rs6000.c	2002/03/12 18:01:18	1.297
--- rs6000.c	2002/03/13 16:48:45
*************** rs6000_va_arg (valist, type)
*** 3096,3143 ****
    int indirect_p, size, rsize, n_reg, sav_ofs, sav_scale;
    rtx lab_false, lab_over, addr_rtx, r;
  
-   /* For AIX, the rule is that structures are passed left-aligned in
-      their stack slot.  However, GCC does not presently do this:
-      structures which are the same size as integer types are passed
-      right-aligned, as if they were in fact integers.  This only
-      matters for structures of size 1 or 2, or 4 when TARGET_64BIT.  */
    if (DEFAULT_ABI != ABI_V4)
!     {
!       HOST_WIDE_INT align, rounded_size;
!       enum machine_mode mode;
!       tree addr_tree;
! 
!       /* Compute the rounded size of the type.  */
!       align = PARM_BOUNDARY / BITS_PER_UNIT;
!       rounded_size = (((int_size_in_bytes (type) + align - 1) / align)
! 		      * align);
! 
!       addr_tree = valist;
! 
!       mode = TYPE_MODE (type);
!       if (mode != BLKmode)
! 	{
! 	  HOST_WIDE_INT adj;
! 	  adj = TREE_INT_CST_LOW (TYPE_SIZE (type)) / BITS_PER_UNIT;
! 	  if (rounded_size > align)
! 	    adj = rounded_size;
! 	  
! 	  addr_tree = build (PLUS_EXPR, TREE_TYPE (addr_tree), addr_tree,
! 			     build_int_2 (rounded_size - adj, 0));
! 	}
! 
!       addr_rtx = expand_expr (addr_tree, NULL_RTX, Pmode, EXPAND_NORMAL);
!       addr_rtx = copy_to_reg (addr_rtx);
!       
!       /* Compute new value for AP.  */
!       t = build (MODIFY_EXPR, TREE_TYPE (valist), valist,
! 		 build (PLUS_EXPR, TREE_TYPE (valist), valist,
! 			build_int_2 (rounded_size, 0)));
!       TREE_SIDE_EFFECTS (t) = 1;
!       expand_expr (t, const0_rtx, VOIDmode, EXPAND_NORMAL);
!       
!       return addr_rtx;
!     }
  
    f_gpr = TYPE_FIELDS (TREE_TYPE (va_list_type_node));
    f_fpr = TREE_CHAIN (f_gpr);
--- 3094,3101 ----
    int indirect_p, size, rsize, n_reg, sav_ofs, sav_scale;
    rtx lab_false, lab_over, addr_rtx, r;
  
    if (DEFAULT_ABI != ABI_V4)
!     return std_expand_builtin_va_arg (valist, type);
  
    f_gpr = TYPE_FIELDS (TREE_TYPE (va_list_type_node));
    f_fpr = TREE_CHAIN (f_gpr);
Index: rs6000.h
===================================================================
RCS file: /cvs/gcc/egcs/gcc/config/rs6000/rs6000.h,v
retrieving revision 1.194
diff -c -p -r1.194 rs6000.h
*** rs6000.h	2002/03/12 18:01:17	1.194
--- rs6000.h	2002/03/13 16:48:46
*************** typedef struct rs6000_args
*** 1697,1702 ****
--- 1697,1710 ----
  #define EXPAND_BUILTIN_VA_ARG(valist, type) \
    rs6000_va_arg (valist, type)
  
+ /* For AIX, the rule is that structures are passed left-aligned in
+    their stack slot.  However, GCC does not presently do this:
+    structures which are the same size as integer types are passed
+    right-aligned, as if they were in fact integers.  This only
+    matters for structures of size 1 or 2, or 4 when TARGET_64BIT.
+    ABI_V4 does not use std_expand_builtin_va_arg.  */
+ #define PAD_VARARGS_DOWN (TYPE_MODE (type) != BLKmode)
+ 
  /* Define this macro to be a nonzero value if the location where a function
     argument is passed depends on whether or not it is a named argument.  */
  #define STRICT_ARGUMENT_NAMING 1