MIPS problem with structures/varargs

[Mark Mitchell]

Gavin --

  How about the attached simple patch?  (It needs a ChangeLog, I
know.)
  
  The definition of FUNCTION_ARG_PADDING here is just what was in
defaults.h (which is what MIPS used before), except that in big-endian
mode, we left-align small things.  (This won't affect passing `char'
because that's promoted to an `int' anyhow; the only small things are
therefore small structures.)

  This fixes the bug on my test case.  But, I haven't got any way to
really test on big-endian MIPS.  Perhaps the test for `mips_abi ==
ABI_32' should also include ABI_N32 and ABI_64?

--
Mark Mitchell                   mark@codesourcery.com
CodeSourcery, LLC               http://www.codesourcery.com

Index: mips.h
===================================================================
RCS file: /egcs/carton/cvsfiles/egcs/gcc/config/mips/mips.h,v
retrieving revision 1.62
diff -c -p -r1.62 mips.h
*** mips.h	1999/08/31 02:16:29	1.62
--- mips.h	1999/09/05 19:04:06
*************** typedef struct mips_args {
*** 2564,2569 ****
--- 2564,2584 ----
  #define FUNCTION_ARG_PARTIAL_NREGS(CUM, MODE, TYPE, NAMED) \
    function_arg_partial_nregs (&CUM, MODE, TYPE, NAMED)
  
+ /* If defined, a C expression which determines whether, and in which
+    direction, to pad out an argument with extra space.  The value
+    should be of type `enum direction': either `upward' to pad above
+    the argument, `downward' to pad below, or `none' to inhibit
+    padding.  */
+ 
+ #define FUNCTION_ARG_PADDING(MODE, TYPE)				\
+   (! BYTES_BIG_ENDIAN							\
+    ? upward								\
+    : (((MODE) == BLKmode						\
+        ? ((TYPE) && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST		\
+ 	  && int_size_in_bytes (TYPE) < (PARM_BOUNDARY / BITS_PER_UNIT)) \
+        : GET_MODE_BITSIZE (MODE) < PARM_BOUNDARY)			\
+       ? ((mips_abi == ABI_32) ? upward : downward) : upward))
+ 
  /* If defined, a C expression that gives the alignment boundary, in
     bits, of an argument with the specified mode and type.  If it is
     not defined,  `PARM_BOUNDARY' is used for all arguments.  */