fr30.h

gcc-you can use this code to learn something about gcc, and inquire further into linux,

         && (TREE_CODE (TYPE_SIZE (TYPE)) != INTEGER_CST	\
	     || TREE_CODE (TYPE) == RECORD_TYPE			\
	     || TREE_CODE (TYPE) == UNION_TYPE			\
	     || TREE_CODE (TYPE) == QUAL_UNION_TYPE		\
             || TREE_ADDRESSABLE (TYPE))))

/* The number of register assigned to holding function arguments.  */
     
#define FR30_NUM_ARG_REGS	 4

/* A C expression that controls whether a function argument is passed in a
   register, and which register.

   The usual way to make the ANSI library `stdarg.h' work on a machine where
   some arguments are usually passed in registers, is to cause nameless
   arguments to be passed on the stack instead.  This is done by making
   `FUNCTION_ARG' return 0 whenever NAMED is 0.

   You may use the macro `MUST_PASS_IN_STACK (MODE, TYPE)' in the definition of
   this macro to determine if this argument is of a type that must be passed in
   the stack.  If `REG_PARM_STACK_SPACE' is not defined and `FUNCTION_ARG'
   returns nonzero for such an argument, the compiler will abort.  If
   `REG_PARM_STACK_SPACE' is defined, the argument will be computed in the
   stack and then loaded into a register.  */
     
#define FUNCTION_ARG(CUM, MODE, TYPE, NAMED)			\
  (  (NAMED) == 0                    ? NULL_RTX			\
   : MUST_PASS_IN_STACK (MODE, TYPE) ? NULL_RTX			\
   : (CUM) >= FR30_NUM_ARG_REGS      ? NULL_RTX			\
   : gen_rtx (REG, MODE, CUM + FIRST_ARG_REGNUM))

/* A C type for declaring a variable that is used as the first argument of
   `FUNCTION_ARG' and other related values.  For some target machines, the type
   `int' suffices and can hold the number of bytes of argument so far.

   There is no need to record in `CUMULATIVE_ARGS' anything about the arguments
   that have been passed on the stack.  The compiler has other variables to
   keep track of that.  For target machines on which all arguments are passed
   on the stack, there is no need to store anything in `CUMULATIVE_ARGS';
   however, the data structure must exist and should not be empty, so use
   `int'.  */
/* On the FR30 this value is an accumulating count of the number of argument
   registers that have been filled with argument values, as opposed to say,
   the number of bytes of argument accumulated so far.  */
#define CUMULATIVE_ARGS int

/* A C expression for the number of words, at the beginning of an argument,
   must be put in registers.  The value must be zero for arguments that are
   passed entirely in registers or that are entirely pushed on the stack.

   On some machines, certain arguments must be passed partially in registers
   and partially in memory.  On these machines, typically the first N words of
   arguments are passed in registers, and the rest on the stack.  If a
   multi-word argument (a `double' or a structure) crosses that boundary, its
   first few words must be passed in registers and the rest must be pushed.
   This macro tells the compiler when this occurs, and how many of the words
   should go in registers.

   `FUNCTION_ARG' for these arguments should return the first register to be
   used by the caller for this argument; likewise `FUNCTION_INCOMING_ARG', for
   the called function.  */
#define FUNCTION_ARG_PARTIAL_NREGS(CUM, MODE, TYPE, NAMED) 	\
  fr30_function_arg_partial_nregs (CUM, MODE, TYPE, NAMED)

/* A C expression that indicates when an argument must be passed by reference.
   If nonzero for an argument, a copy of that argument is made in memory and a
   pointer to the argument is passed instead of the argument itself.  The
   pointer is passed in whatever way is appropriate for passing a pointer to
   that type.

   On machines where `REG_PARM_STACK_SPACE' is not defined, a suitable
   definition of this macro might be:
        #define FUNCTION_ARG_PASS_BY_REFERENCE(CUM, MODE, TYPE, NAMED)  \
          MUST_PASS_IN_STACK (MODE, TYPE)  */
#define FUNCTION_ARG_PASS_BY_REFERENCE(CUM, MODE, TYPE, NAMED) \
  MUST_PASS_IN_STACK (MODE, TYPE)

/* A C statement (sans semicolon) for initializing the variable CUM for the
   state at the beginning of the argument list.  The variable has type
   `CUMULATIVE_ARGS'.  The value of FNTYPE is the tree node for the data type
   of the function which will receive the args, or 0 if the args are to a
   compiler support library function.  The value of INDIRECT is nonzero when
   processing an indirect call, for example a call through a function pointer.
   The value of INDIRECT is zero for a call to an explicitly named function, a
   library function call, or when `INIT_CUMULATIVE_ARGS' is used to find
   arguments for the function being compiled.

   When processing a call to a compiler support library function, LIBNAME
   identifies which one.  It is a `symbol_ref' rtx which contains the name of
   the function, as a string.  LIBNAME is 0 when an ordinary C function call is
   being processed.  Thus, each time this macro is called, either LIBNAME or
   FNTYPE is nonzero, but never both of them at once.  */
#define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, INDIRECT) (CUM) = 0

/* A C statement (sans semicolon) to update the summarizer variable CUM to
   advance past an argument in the argument list.  The values MODE, TYPE and
   NAMED describe that argument.  Once this is done, the variable CUM is
   suitable for analyzing the *following* argument with `FUNCTION_ARG', etc.

   This macro need not do anything if the argument in question was passed on
   the stack.  The compiler knows how to track the amount of stack space used
   for arguments without any special help.  */
#define FUNCTION_ARG_ADVANCE(CUM, MODE, TYPE, NAMED)			\
  (CUM) += (NAMED) * fr30_num_arg_regs (MODE, TYPE)

/* A C expression that is nonzero if REGNO is the number of a hard register in
   which function arguments are sometimes passed.  This does *not* include
   implicit arguments such as the static chain and the structure-value address.
   On many machines, no registers can be used for this purpose since all
   function arguments are pushed on the stack.  */
#define FUNCTION_ARG_REGNO_P(REGNO) \
  ((REGNO) >= FIRST_ARG_REGNUM && ((REGNO) < FIRST_ARG_REGNUM + FR30_NUM_ARG_REGS))

/*}}}*/ 
/*{{{  How Scalar Function Values are Returned.  */ 

/* A C expression to create an RTX representing the place where a function
   returns a value of data type VALTYPE.  VALTYPE is a tree node representing a
   data type.  Write `TYPE_MODE (VALTYPE)' to get the machine mode used to
   represent that type.  On many machines, only the mode is relevant.
   (Actually, on most machines, scalar values are returned in the same place
   regardless of mode).

   If `PROMOTE_FUNCTION_RETURN' is defined, you must apply the same promotion
   rules specified in `PROMOTE_MODE' if VALTYPE is a scalar type.

   If the precise function being called is known, FUNC is a tree node
   (`FUNCTION_DECL') for it; otherwise, FUNC is a null pointer.  This makes it
   possible to use a different value-returning convention for specific
   functions when all their calls are known.

   `FUNCTION_VALUE' is not used for return vales with aggregate data types,
   because these are returned in another way.  See `STRUCT_VALUE_REGNUM' and
   related macros, below.  */
#define FUNCTION_VALUE(VALTYPE, FUNC) \
     gen_rtx_REG (TYPE_MODE (VALTYPE), RETURN_VALUE_REGNUM)

/* A C expression to create an RTX representing the place where a library
   function returns a value of mode MODE.  If the precise function being called
   is known, FUNC is a tree node (`FUNCTION_DECL') for it; otherwise, FUNC is a
   null pointer.  This makes it possible to use a different value-returning
   convention for specific functions when all their calls are known.

   Note that "library function" in this context means a compiler support
   routine, used to perform arithmetic, whose name is known specially by the
   compiler and was not mentioned in the C code being compiled.

   The definition of `LIBRARY_VALUE' need not be concerned aggregate data
   types, because none of the library functions returns such types.  */
#define LIBCALL_VALUE(MODE) gen_rtx (REG, MODE, RETURN_VALUE_REGNUM)

/* A C expression that is nonzero if REGNO is the number of a hard register in
   which the values of called function may come back. */

#define FUNCTION_VALUE_REGNO_P(REGNO) ((REGNO) == RETURN_VALUE_REGNUM)

/*}}}*/ 
/*{{{  How Large Values are Returned.  */ 

/* Define this macro to be 1 if all structure and union return values must be
   in memory.  Since this results in slower code, this should be defined only
   if needed for compatibility with other compilers or with an ABI.  If you
   define this macro to be 0, then the conventions used for structure and union
   return values are decided by the `RETURN_IN_MEMORY' macro.

   If not defined, this defaults to the value 1.  */
#define DEFAULT_PCC_STRUCT_RETURN 1

/* If the structure value address is not passed in a register, define
   `STRUCT_VALUE' as an expression returning an RTX for the place where the
   address is passed.  If it returns 0, the address is passed as an "invisible"
   first argument.  */
#define STRUCT_VALUE 0

/*}}}*/ 
/*{{{  Generating Code for Profiling.  */ 

/* A C statement or compound statement to output to FILE some assembler code to
   call the profiling subroutine `mcount'.  Before calling, the assembler code
   must load the address of a counter variable into a register where `mcount'
   expects to find the address.  The name of this variable is `LP' followed by
   the number LABELNO, so you would generate the name using `LP%d' in a
   `fprintf'.

   The details of how the address should be passed to `mcount' are determined
   by your operating system environment, not by GNU CC.  To figure them out,
   compile a small program for profiling using the system's installed C
   compiler and look at the assembler code that results.  */
#define FUNCTION_PROFILER(FILE, LABELNO)	\
{						\
  fprintf (FILE, "\t mov rp, r1\n" );		\
  fprintf (FILE, "\t ldi:32 mcount, r0\n" );	\
  fprintf (FILE, "\t call @r0\n" );		\
  fprintf (FILE, ".word\tLP%d\n", LABELNO);	\
}

/*}}}*/ 
/*{{{  Implementing the VARARGS Macros.  */ 

/* This macro offers an alternative to using `__builtin_saveregs' and defining
   the macro `EXPAND_BUILTIN_SAVEREGS'.  Use it to store the anonymous register
   arguments into the stack so that all the arguments appear to have been
   passed consecutively on the stack.  Once this is done, you can use the
   standard implementation of varargs that works for machines that pass all
   their arguments on the stack.

   The argument ARGS_SO_FAR is the `CUMULATIVE_ARGS' data structure, containing
   the values that obtain after processing of the named arguments.  The
   arguments MODE and TYPE describe the last named argument--its machine mode
   and its data type as a tree node.

   The macro implementation should do two things: first, push onto the stack
   all the argument registers *not* used for the named arguments, and second,
   store the size of the data thus pushed into the `int'-valued variable whose
   name is supplied as the argument PRETEND_ARGS_SIZE.  The value that you
   store here will serve as additional offset for setting up the stack frame.

   Because you must generate code to push the anonymous arguments at compile
   time without knowing their data types, `SETUP_INCOMING_VARARGS' is only
   useful on machines that have just a single category of argument register and
   use it uniformly for all data types.

   If the argument SECOND_TIME is nonzero, it means that the arguments of the
   function are being analyzed for the second time.  This happens for an inline
   function, which is not actually compiled until the end of the source file.
   The macro `SETUP_INCOMING_VARARGS' should not generate any instructions in
   this case.  */
#define SETUP_INCOMING_VARARGS(ARGS_SO_FAR, MODE, TYPE, PRETEND_ARGS_SIZE, SECOND_TIME) \
  if (! SECOND_TIME) \
    fr30_setup_incoming_varargs (ARGS_SO_FAR, MODE, TYPE, & PRETEND_ARGS_SIZE)

/* Define this macro if the location where a function argument is passed
   depends on whether or not it is a named argument.

   This macro controls how the NAMED argument to `FUNCTION_ARG' is set for
   varargs and stdarg functions.  With this macro defined, the NAMED argument
   is always true for named arguments, and false for unnamed arguments.  If
   this is not defined, but `SETUP_INCOMING_VARARGS' is defined, then all
   arguments are treated as named.  Otherwise, all named arguments except the
   last are treated as named.  */
#define STRICT_ARGUMENT_NAMING 0

/*}}}*/ 
/*{{{  Trampolines for Nested Functions.  */ 

/* On the FR30, the trampoline is:

   nop
   ldi:32 STATIC, r12
   nop
   ldi:32 FUNCTION, r0
   jmp    @r0

   The no-ops are to guarantee that the static chain and final
   target are 32 bit ailgned within the trampoline.  That allows us to
   initialize those locations with simple SImode stores.   The alternative
   would be to use HImode stores.  */
   
/* A C statement to output, on the stream FILE, assembler code for a block of
   data that contains the constant parts of a trampoline.  This code should not
   include a label--the label is taken care of automatically.  */
#define TRAMPOLINE_TEMPLATE(FILE)						\
{										\
  fprintf (FILE, "\tnop\n");							\
  fprintf (FILE, "\tldi:32\t#0, %s\n", reg_names [STATIC_CHAIN_REGNUM]);	\
  fprintf (FILE, "\tnop\n");							\
  fprintf (FILE, "\tldi:32\t#0, %s\n", reg_names [COMPILER_SCRATCH_REGISTER]);	\
  fprintf (FILE, "\tjmp\t@%s\n", reg_names [COMPILER_SCRATCH_REGISTER]);	\
}

/* A C expression for the size in bytes of the trampoline, as an integer.  */
#define TRAMPOLINE_SIZE 18

/* We want the trampoline to be aligned on a 32bit boundary so that we can
   make sure the location of the static chain & target function within
   the trampoline is also aligned on a 32bit boundary.  */
#define TRAMPOLINE_ALIGNMENT 32

/* A C statement to initialize the variable parts of a trampoline.  ADDR is an
   RTX for the address of the trampoline; FNADDR is an RTX for the address of
   the nested function; STATIC_CHAIN is an RTX for the static chain value that
   should be passed to the function when it is called.  */
#define INITIALIZE_TRAMPOLINE(ADDR, FNADDR, STATIC_CHAIN)			\
do										\
{										\
  emit_move_insn (gen_rtx (MEM, SImode, plus_constant (ADDR, 4)), STATIC_CHAIN);\
  emit_move_insn (gen_rtx (MEM, SImode, plus_constant (ADDR, 12)), FNADDR);	\
} while (0);

/*}}}*/ 
/*{{{  Addressing Modes.  */ 

/* A C expression that is 1 if the RTX X is a constant which is a valid
   address.  On most machines, this can be defined as `CONSTANT_P (X)', but a
   few machines are more restrictive in which constant addresses are supported.

   `CONSTANT_P' accepts integer-values expressions whose values are not
   explicitly known, such as `symbol_ref', `label_ref', and `high' expressions
   and `const' arithmetic expressions, in addition to `const_int' and
   `const_double' expressions.  */
#define CONSTANT_ADDRESS_P(X) CONSTANT_P (X)

/* A number, the maximum number of registers that can appear in a valid memory
   address.  Note that it is up to you to specify a value equal to the maximum
   number that `GO_IF_LEGITIMATE_ADDRESS' would ever accept.  */
#define MAX_REGS_PER_ADDRESS 1

/* A C compound statement with a conditional `goto LABEL;' executed if X (an
   RTX) is a legitimate memory address on the target machine for a memory
   operand of mode MODE.  */

/* On the FR30 we only have one real addressing mode - an address in a
   register.  There are three special cases however:
   
   * indexed addressing using small positive offsets from the stack pointer
   
   * indexed addressing using small signed offsets from the frame pointer

   * register plus register addressing using R13 as the base register.

   At the moment we only support the first two of these special cases.  */
   
#ifdef REG_OK_STRICT
#define GO_IF_LEGITIMATE_ADDRESS(MODE, X, LABEL)			\
  do									\
    {									\
      if (GET_CODE (X) == REG && REG_OK_FOR_BASE_P (X))			\
        goto LABEL;							\
      if (GET_CODE (X) == PLUS						\
	  && ((MODE) == SImode || (MODE) == SFmode)			\
	  && XEXP (X, 0) == stack_pointer_rtx				\
	  && GET_CODE (XEXP (X, 1)) == CONST_INT			\
	  && IN_RANGE (INTVAL (XEXP (X, 1)), 0, (1 <<  6) - 4))		\
	goto LABEL;							\
      if (GET_CODE (X) == PLUS						\
	  && ((MODE) == SImode || (MODE) == SFmode)			\
	  && XEXP (X, 0) == frame_pointer_rtx				\