rx.c (rx_function_value): Small integer types are promotes to SImode.

        * config/rx/rx.c (rx_function_value): Small integer types are
        promotes to SImode.
        (rx_promote_function_mode): New function.
        (TARGET_PROMOTE_FUNCTION_MODE): Define.

From-SVN: r165690

gcc/ChangeLog

 2010-10-19  Nick Clifton  <nickc@redhat.com>
 
+	* config/rx/rx.c (rx_function_value): Small integer types are
+	promotes to SImode.
+	(rx_promote_function_mode): New function.
+	(TARGET_PROMOTE_FUNCTION_MODE): Define.
+
+2010-10-19  Nick Clifton  <nickc@redhat.com>
+
 	* config/mep/mep.c (mep_print_operand): Use
 	targetm.strip_name_encoding.
 	(mep_output_aligned_common): Likewise.

gcc/config/rx/rx.c

@@ -830,7 +830,32 @@ rx_function_value (const_tree ret_type,
 		   const_tree fn_decl_or_type ATTRIBUTE_UNUSED,
 		   bool       outgoing ATTRIBUTE_UNUSED)
 {
-  return gen_rtx_REG (TYPE_MODE (ret_type), FUNC_RETURN_REGNUM);
+  enum machine_mode mode = TYPE_MODE (ret_type);
+
+  /* RX ABI specifies that small integer types are
+     promoted to int when returned by a function.  */
+  if (GET_MODE_SIZE (mode) > 0 && GET_MODE_SIZE (mode) < 4)
+    return gen_rtx_REG (SImode, FUNC_RETURN_REGNUM);
+    
+  return gen_rtx_REG (mode, FUNC_RETURN_REGNUM);
+}
+
+/* TARGET_PROMOTE_FUNCTION_MODE must behave in the same way with
+   regard to function returns as does TARGET_FUNCTION_VALUE.  */
+
+static enum machine_mode
+rx_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
+			  enum machine_mode mode,
+			  int * punsignedp,
+			  const_tree funtype ATTRIBUTE_UNUSED,
+			  int for_return)
+{
+  if (for_return != 1
+      || GET_MODE_SIZE (mode) >= 4
+      || GET_MODE_SIZE (mode) < 1)
+    return mode;
+
+  return SImode;
 }
 
 static bool
@@ -2825,6 +2850,9 @@ rx_memory_move_cost (enum machine_mode mode, enum reg_class regclass, bool in)
 #undef  TARGET_OPTION_OVERRIDE
 #define TARGET_OPTION_OVERRIDE			rx_option_override
 
+#undef  TARGET_PROMOTE_FUNCTION_MODE
+#define TARGET_PROMOTE_FUNCTION_MODE		rx_promote_function_mode
+
 #undef  TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE
 #define TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE	rx_override_options_after_change