Fixes for powerpc-linux param passing

[Alan Modra]

Applying as obvious.  UNITS_PER_WORD is wrong when -m32 -mpowerpc64.
The code that I'm reinstating here is to handle types such as
_Complex long long, which aren't aligned.

	* config/rs6000/rs6000.c (rs6000_va_arg <ABI_V4>): Don't use
	UNITS_PER_WORD to calculate gpr size.  Re-instate code to set reg
	count to 8 to handle n_reg > 2.

Index: gcc/config/rs6000/rs6000.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/rs6000/rs6000.c,v
retrieving revision 1.642
diff -u -p -r1.642 rs6000.c
--- gcc/config/rs6000/rs6000.c	13 May 2004 06:40:04 -0000	1.642
+++ gcc/config/rs6000/rs6000.c	15 May 2004 04:33:31 -0000
@@ -5144,7 +5144,7 @@ rs6000_va_arg (tree valist, tree type)
   sav = build (COMPONENT_REF, TREE_TYPE (f_sav), valist, f_sav);
 
   size = int_size_in_bytes (type);
-  rsize = (size + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
+  rsize = (size + 3) / 4;
   align = 1;
 
   if (AGGREGATE_TYPE_P (type)
@@ -5158,7 +5158,7 @@ rs6000_va_arg (tree valist, tree type)
       n_reg = 1;
       sav_ofs = 0;
       sav_scale = 4;
-      size = UNITS_PER_WORD;
+      size = 4;
       rsize = 1;
     }
   else if (TARGET_HARD_FLOAT && TARGET_FPRS
@@ -5240,6 +5240,14 @@ rs6000_va_arg (tree valist, tree type)
       emit_barrier ();
 
       emit_label (lab_false);
+      if (n_reg > 2)
+	{
+	  /* Ensure that we don't find any more args in regs.
+	     Alignment has taken care of the n_reg == 2 case.  */
+	  t = build (MODIFY_EXPR, TREE_TYPE (reg), reg, build_int_2 (8, 0));
+	  TREE_SIDE_EFFECTS (t) = 1;
+	  expand_expr (t, const0_rtx, VOIDmode, EXPAND_NORMAL);
+	}
     }
 
   /* ... otherwise out of the overflow area.  */

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre