[RFA] fix calling conventions wrt 32-bit values

[Richard Henderson <rth@twiddle.net>]

Ok?


r~


	* alpha-tdep.c (alpha_push_dummy_call): Handle ABI mandated 
	sign-extension of 32-bit values.
	(alpha_store_return_value): Similarly.


--- alpha-tdep.c.5	2003-06-01 22:34:01.000000000 -0700
+++ alpha-tdep.c	2003-06-01 22:42:32.000000000 -0700
@@ -276,9 +276,16 @@ alpha_push_dummy_call (struct gdbarch *g
 	case TYPE_CODE_CHAR:
 	case TYPE_CODE_RANGE:
 	case TYPE_CODE_ENUM:
-	  if (TYPE_LENGTH (arg_type) < TYPE_LENGTH (builtin_type_long))
+	  if (TYPE_LENGTH (arg_type) == 4)
 	    {
-	      arg_type = builtin_type_long;
+	      /* 32-bit values must be sign-extended to 64 bits
+		 even if the base data type is unsigned.  */
+	      arg_type = builtin_type_int32;
+	      arg = value_cast (arg_type, arg);
+	    }
+	  if (TYPE_LENGTH (arg_type) < ALPHA_REGISTER_SIZE)
+	    {
+	      arg_type = builtin_type_int64;
 	      arg = value_cast (arg_type, arg);
 	    }
 	  break;
@@ -541,6 +548,10 @@ alpha_store_return_value (struct type *v
 
     default:
       /* Assume everything else degenerates to an integer.  */
+      /* 32-bit values must be sign-extended to 64 bits
+	 even if the base data type is unsigned.  */
+      if (length == 4)
+	valtype = builtin_type_int32;
       l = unpack_long (valtype, valbuf);
       regcache_cooked_write_unsigned (regcache, ALPHA_V0_REGNUM, l);
       break;