[RFA] mips_push_arguments: N32/N64 struct arguments

[Kevin Buettner <kevinb@redhat.com>]

The patch below addresses some details in how N32 and N64 struct and
union arguments are passed.  When using the SGI compiler, I'm seeing
the following failures fixed with this patch:

FAIL: gdb.base/call-ar-st.exp: print sum_array_print(10, *list1, *list2, *list3, *list4)
FAIL: gdb.base/call-ar-st.exp: print print_long_arg_list, pattern 12

For N32, this patch depends upon my previous patch:

    [RFA] mips-tdep.c: Set mips_default_saved_regsize to 8 for N32

Okay to commit?

	* mips-tdep.c (mips_push_arguments): For N32 and N64 ABIs, don't
	write odd sized struct arguments living in registers to the stack.
	For small struct and union arguments not living in registers,
	don't shift the struct when writing to the stack.

Index: mips-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/mips-tdep.c,v
retrieving revision 1.85
diff -u -p -r1.85 mips-tdep.c
--- mips-tdep.c	31 Jul 2002 20:26:49 -0000	1.85
+++ mips-tdep.c	31 Jul 2002 23:07:27 -0000
@@ -2536,7 +2536,9 @@ mips_push_arguments (int nargs,
 
 	      /* Write this portion of the argument to the stack.  */
 	      if (argreg > MIPS_LAST_ARG_REGNUM
-		  || odd_sized_struct
+		  || (odd_sized_struct 
+		      && tdep->mips_abi != MIPS_ABI_N32
+		      && tdep->mips_abi != MIPS_ABI_N64)
 		  || fp_register_arg_p (typecode, arg_type))
 		{
 		  /* Should shorter than int integer values be
@@ -2552,8 +2554,10 @@ mips_push_arguments (int nargs,
 			   typecode == TYPE_CODE_FLT) && len <= 4)
 			longword_offset = MIPS_STACK_ARGSIZE - len;
 		      else if ((typecode == TYPE_CODE_STRUCT ||
-				typecode == TYPE_CODE_UNION) &&
-			       TYPE_LENGTH (arg_type) < MIPS_STACK_ARGSIZE)
+				typecode == TYPE_CODE_UNION)
+			       && TYPE_LENGTH (arg_type) < MIPS_STACK_ARGSIZE
+			       && tdep->mips_abi != MIPS_ABI_N32
+			       && tdep->mips_abi != MIPS_ABI_N64)
 			longword_offset = MIPS_STACK_ARGSIZE - len;
 		    }