[xtensa] hookize FUNCTION_ARG &co.

This patch hookizes FUNCTION_ARG and related macros for the Xtensa
backend.  Nothing much to see here.

Tested with xtensa-elf and comparing assembly before/after.  I plan to
commit this under the obvious rule after waiting a week for comments.

-Nathan

	* config/xtensa/xtensa-protos.h (function_arg_advance): Delete.
	(function_arg): Delete.
	* config/xtensa/xtensa.h (FUNCTION_ARG, FUNCTION_ARG_ADVANCE): Delete.
	(FUNCTION_INCOMING_ARG): Delete.
	* config/xtensa/xtensa.c (function_arg_advance): Rename to...
	(xtensa_function_arg_advance): ...this.  Make static.  Take a const_tree
	and a bool.
	(function_arg): Rename to...
	(xtensa_function_arg_1): ...this.  Make static.  Take a const_tree and
	a bool.
	(xtensa_function_arg, xtensa_function_incoming_arg): Nex functions.
	(TARGET_FUNCTION_ARG, TARGET_FUNCTION_ARG_ADVANCE): Define.
	(TARGET_FUNCTION_INCOMING_ARG): Define.

Looks fine. Thanks for the fix.

Sterling

Nathan Froyd wrote:
> This patch hookizes FUNCTION_ARG and related macros for the Xtensa
> backend.  Nothing much to see here.
> 
> Tested with xtensa-elf and comparing assembly before/after.  I plan to
> commit this under the obvious rule after waiting a week for comments.
> 
> -Nathan
> 
> 	* config/xtensa/xtensa-protos.h (function_arg_advance): Delete.
> 	(function_arg): Delete.
> 	* config/xtensa/xtensa.h (FUNCTION_ARG, FUNCTION_ARG_ADVANCE): Delete.
> 	(FUNCTION_INCOMING_ARG): Delete.
> 	* config/xtensa/xtensa.c (function_arg_advance): Rename to...
> 	(xtensa_function_arg_advance): ...this.  Make static.  Take a const_tree
> 	and a bool.
> 	(function_arg): Rename to...
> 	(xtensa_function_arg_1): ...this.  Make static.  Take a const_tree and
> 	a bool.
> 	(xtensa_function_arg, xtensa_function_incoming_arg): Nex functions.
> 	(TARGET_FUNCTION_ARG, TARGET_FUNCTION_ARG_ADVANCE): Define.
> 	(TARGET_FUNCTION_INCOMING_ARG): Define.
> 
> diff --git a/gcc/config/xtensa/xtensa-protos.h b/gcc/config/xtensa/xtensa-protos.h
> index 729bc84..18c08d7 100644
> --- a/gcc/config/xtensa/xtensa-protos.h
> +++ b/gcc/config/xtensa/xtensa-protos.h
> @@ -73,9 +73,6 @@ extern reg_class_t xtensa_secondary_reload (bool, rtx, reg_class_t,
>  #endif /* RTX_CODE */
>  
>  #ifdef TREE_CODE
> -extern void function_arg_advance (CUMULATIVE_ARGS *, enum machine_mode, tree);
> -extern struct rtx_def *function_arg (CUMULATIVE_ARGS *, enum machine_mode,
> -				     tree, int);
>  extern int function_arg_boundary (enum machine_mode, tree);
>  #endif /* TREE_CODE */
>  
> diff --git a/gcc/config/xtensa/xtensa.c b/gcc/config/xtensa/xtensa.c
> index 610a272..f81452a 100644
> --- a/gcc/config/xtensa/xtensa.c
> +++ b/gcc/config/xtensa/xtensa.c
> @@ -140,6 +140,12 @@ static tree xtensa_build_builtin_va_list (void);
>  static bool xtensa_return_in_memory (const_tree, const_tree);
>  static tree xtensa_gimplify_va_arg_expr (tree, tree, gimple_seq *,
>  					 gimple_seq *);
> +static void xtensa_function_arg_advance (CUMULATIVE_ARGS *, enum machine_mode,
> +					 const_tree, bool);
> +static rtx xtensa_function_arg (CUMULATIVE_ARGS *, enum machine_mode,
> +				const_tree, bool);
> +static rtx xtensa_function_incoming_arg (CUMULATIVE_ARGS *,
> +					 enum machine_mode, const_tree, bool);
>  static rtx xtensa_function_value (const_tree, const_tree, bool);
>  static void xtensa_init_builtins (void);
>  static tree xtensa_fold_builtin (tree, int, tree *, bool);
> @@ -201,6 +207,12 @@ static const int reg_nonleaf_alloc_order[FIRST_PSEUDO_REGISTER] =
>  #define TARGET_SPLIT_COMPLEX_ARG hook_bool_const_tree_true
>  #undef TARGET_MUST_PASS_IN_STACK
>  #define TARGET_MUST_PASS_IN_STACK must_pass_in_stack_var_size
> +#undef TARGET_FUNCTION_ARG_ADVANCE
> +#define TARGET_FUNCTION_ARG_ADVANCE xtensa_function_arg_advance
> +#undef TARGET_FUNCTION_ARG
> +#define TARGET_FUNCTION_ARG xtensa_function_arg
> +#undef TARGET_FUNCTION_INCOMING_ARG
> +#define TARGET_FUNCTION_INCOMING_ARG xtensa_function_incoming_arg
>  
>  #undef TARGET_EXPAND_BUILTIN_SAVEREGS
>  #define TARGET_EXPAND_BUILTIN_SAVEREGS xtensa_builtin_saveregs
> @@ -1983,8 +1995,9 @@ init_cumulative_args (CUMULATIVE_ARGS *cum, int incoming)
>  
>  /* Advance the argument to the next argument position.  */
>  
> -void
> -function_arg_advance (CUMULATIVE_ARGS *cum, enum machine_mode mode, tree type)
> +static void
> +xtensa_function_arg_advance (CUMULATIVE_ARGS *cum, enum machine_mode mode,
> +			     const_tree type, bool named ATTRIBUTE_UNUSED)
>  {
>    int words, max;
>    int *arg_words;
> @@ -2009,9 +2022,9 @@ function_arg_advance (CUMULATIVE_ARGS *cum, enum machine_mode mode, tree type)
>     or 0 if the argument is to be passed on the stack.  INCOMING_P is nonzero
>     if this is an incoming argument to the current function.  */
>  
> -rtx
> -function_arg (CUMULATIVE_ARGS *cum, enum machine_mode mode, tree type,
> -	      int incoming_p)
> +static rtx
> +xtensa_function_arg_1 (const CUMULATIVE_ARGS *cum, enum machine_mode mode,
> +		       const_tree type, bool incoming_p)
>  {
>    int regbase, words, max;
>    int *arg_words;
> @@ -2042,6 +2055,23 @@ function_arg (CUMULATIVE_ARGS *cum, enum machine_mode mode, tree type,
>    return gen_rtx_REG (mode, regno);
>  }
>  
> +/* Implement TARGET_FUNCTION_ARG.  */
> +
> +static rtx
> +xtensa_function_arg (CUMULATIVE_ARGS *cum, enum machine_mode mode,
> +		     const_tree type, bool named ATTRIBUTE_UNUSED)
> +{
> +  return xtensa_function_arg_1 (cum, mode, type, false);
> +}
> +
> +/* Implement TARGET_FUNCTION_INCOMING_ARG.  */
> +
> +static rtx
> +xtensa_function_incoming_arg (CUMULATIVE_ARGS *cum, enum machine_mode mode,
> +			      const_tree type, bool named ATTRIBUTE_UNUSED)
> +{
> +  return xtensa_function_arg_1 (cum, mode, type, true);
> +}
>  
>  int
>  function_arg_boundary (enum machine_mode mode, tree type)
> diff --git a/gcc/config/xtensa/xtensa.h b/gcc/config/xtensa/xtensa.h
> index 32819bc..153242a 100644
> --- a/gcc/config/xtensa/xtensa.h
> +++ b/gcc/config/xtensa/xtensa.h
> @@ -618,18 +618,6 @@ typedef struct xtensa_args
>  #define INIT_CUMULATIVE_INCOMING_ARGS(CUM, FNTYPE, LIBNAME)		\
>    init_cumulative_args (&CUM, 1)
>  
> -/* Update the data in CUM to advance over an argument
> -   of mode MODE and data type TYPE.
> -   (TYPE is null for libcalls where that information may not be available.)  */
> -#define FUNCTION_ARG_ADVANCE(CUM, MODE, TYPE, NAMED)			\
> -  function_arg_advance (&CUM, MODE, TYPE)
> -
> -#define FUNCTION_ARG(CUM, MODE, TYPE, NAMED) \
> -  function_arg (&CUM, MODE, TYPE, FALSE)
> -
> -#define FUNCTION_INCOMING_ARG(CUM, MODE, TYPE, NAMED) \
> -  function_arg (&CUM, MODE, TYPE, TRUE)
> -
>  #define FUNCTION_ARG_BOUNDARY function_arg_boundary
>  
>  /* Profiling Xtensa code is typically done with the built-in profiling