[s390] hookize FUNCTION_ARG &co.

diff --git a/gcc/config/s390/s390-protos.h b/gcc/config/s390/s390-protos.h
index 8a2f1b7..604dc5a 100644
--- a/gcc/config/s390/s390-protos.h
+++ b/gcc/config/s390/s390-protos.h
@@ -118,10 +118,7 @@  extern int s390_compare_and_branch_condition_mask (rtx);
 #endif /* RTX_CODE */
 
 #ifdef TREE_CODE
-extern void s390_function_arg_advance (CUMULATIVE_ARGS *, enum machine_mode,
-				       tree, int);
 #ifdef RTX_CODE
-extern rtx s390_function_arg (CUMULATIVE_ARGS *, enum machine_mode, tree, int);
 extern rtx s390_function_value (const_tree, const_tree, enum machine_mode);
 #endif /* RTX_CODE */
 #endif /* TREE_CODE */
diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c
index 56cbac2..d262527 100644
--- a/gcc/config/s390/s390.c
+++ b/gcc/config/s390/s390.c
@@ -8263,7 +8263,7 @@  s390_function_arg_size (enum machine_mode mode, const_tree type)
    is to be passed in a floating-point register, if available.  */
 
 static bool
-s390_function_arg_float (enum machine_mode mode, tree type)
+s390_function_arg_float (enum machine_mode mode, const_tree type)
 {
   int size = s390_function_arg_size (mode, type);
   if (size > 8)
@@ -8308,7 +8308,7 @@  s390_function_arg_float (enum machine_mode mode, tree type)
    registers, if available.  */
 
 static bool
-s390_function_arg_integer (enum machine_mode mode, tree type)
+s390_function_arg_integer (enum machine_mode mode, const_tree type)
 {
   int size = s390_function_arg_size (mode, type);
   if (size > 8)
@@ -8370,9 +8370,9 @@  s390_pass_by_reference (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
    argument is a named argument (as opposed to an unnamed argument
    matching an ellipsis).  */
 
-void
+static void
 s390_function_arg_advance (CUMULATIVE_ARGS *cum, enum machine_mode mode,
-			   tree type, int named ATTRIBUTE_UNUSED)
+			   const_tree type, bool named ATTRIBUTE_UNUSED)
 {
   if (s390_function_arg_float (mode, type))
     {
@@ -8406,9 +8406,9 @@  s390_function_arg_advance (CUMULATIVE_ARGS *cum, enum machine_mode mode,
    to pass floating point arguments.  All remaining arguments
    are pushed to the stack.  */
 
-rtx
-s390_function_arg (CUMULATIVE_ARGS *cum, enum machine_mode mode, tree type,
-		   int named ATTRIBUTE_UNUSED)
+static rtx
+s390_function_arg (CUMULATIVE_ARGS *cum, enum machine_mode mode,
+		   const_tree type, bool named ATTRIBUTE_UNUSED)
 {
   if (s390_function_arg_float (mode, type))
     {
@@ -10483,6 +10483,10 @@  s390_loop_unroll_adjust (unsigned nunroll, struct loop *loop)
 
 #undef TARGET_FUNCTION_OK_FOR_SIBCALL
 #define TARGET_FUNCTION_OK_FOR_SIBCALL s390_function_ok_for_sibcall
+#undef TARGET_FUNCTION_ARG
+#define TARGET_FUNCTION_ARG s390_function_arg
+#undef TARGET_FUNCTION_ARG_ADVANCE
+#define TARGET_FUNCTION_ARG_ADVANCE s390_function_arg_advance
 
 #undef TARGET_FIXED_CONDITION_CODE_REGS
 #define TARGET_FIXED_CONDITION_CODE_REGS s390_fixed_condition_code_regs
diff --git a/gcc/config/s390/s390.h b/gcc/config/s390/s390.h
index cbe2899..94f1810 100644
--- a/gcc/config/s390/s390.h
+++ b/gcc/config/s390/s390.h
@@ -686,12 +686,6 @@  CUMULATIVE_ARGS;
 #define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, NN, N_NAMED_ARGS) \
   ((CUM).gprs=0, (CUM).fprs=0)
 
-#define FUNCTION_ARG_ADVANCE(CUM, MODE, TYPE, NAMED)                    \
-  s390_function_arg_advance (&CUM, MODE, TYPE, NAMED)
-
-#define FUNCTION_ARG(CUM, MODE, TYPE, NAMED)   \
-  s390_function_arg (&CUM, MODE, TYPE, NAMED)
-
 /* Arguments can be placed in general registers 2 to 6, or in floating
    point registers 0 and 2 for 31 bit and fprs 0, 2, 4 and 6 for 64
    bit.  */