rs6000.h

早期freebsd实现

/* Determine where to put an argument to a function.
   Value is zero to push the argument on the stack,
   or a hard register in which to store the argument.

   MODE is the argument's machine mode.
   TYPE is the data type of the argument (as a tree).
    This is null for libcalls where that information may
    not be available.
   CUM is a variable of type CUMULATIVE_ARGS which gives info about
    the preceding args and about the function being called.
   NAMED is nonzero if this argument is a named parameter
    (otherwise it is an extra parameter matching an ellipsis).

   On RS/6000 the first eight words of non-FP are normally in registers
   and the rest are pushed.  The first 13 FP args are in registers.

   If this is floating-point and no prototype is specified, we use
   both an FP and integer register (or possibly FP reg and stack).  Library
   functions (when TYPE is zero) always have the proper types for args,
   so we can pass the FP value just in one register.  emit_library_function
   doesn't support EXPR_LIST anyway.  */

#define FUNCTION_ARG(CUM, MODE, TYPE, NAMED)				\
  (! (NAMED) ? 0							\
   : ((TYPE) != 0 && TREE_CODE (TYPE_SIZE (TYPE)) != INTEGER_CST) ? 0	\
   : USE_FP_FOR_ARG_P (CUM, MODE, TYPE)					\
   ? ((CUM).nargs_prototype > 0 || (TYPE) == 0				\
      ? gen_rtx (REG, MODE, (CUM).fregno)				\
      : ((CUM).words < 8						\
	 ? gen_rtx (EXPR_LIST, VOIDmode,				\
		    gen_rtx (REG, (MODE), 3 + (CUM).words),		\
		    gen_rtx (REG, (MODE), (CUM).fregno))		\
	 : gen_rtx (EXPR_LIST, VOIDmode, 0,				\
		    gen_rtx (REG, (MODE), (CUM).fregno))))		\
   : (CUM).words < 8 ? gen_rtx(REG, (MODE), 3 + (CUM).words) : 0)

/* For an arg passed partly in registers and partly in memory,
   this is the number of registers used.
   For args passed entirely in registers or entirely in memory, zero.  */

#define FUNCTION_ARG_PARTIAL_NREGS(CUM, MODE, TYPE, NAMED)		\
  (! (NAMED) ? 0							\
   : USE_FP_FOR_ARG_P (CUM, MODE, TYPE) && (CUM).nargs_prototype >= 0 ? 0 \
   : (((CUM).words < 8							\
       && 8 < ((CUM).words + RS6000_ARG_SIZE (MODE, TYPE, NAMED)))	\
      ? 8 - (CUM).words : 0))

/* Perform any needed actions needed for a function that is receiving a
   variable number of arguments. 

   CUM is as above.

   MODE and TYPE are the mode and type of the current parameter.

   PRETEND_SIZE is a variable that should be set to the amount of stack
   that must be pushed by the prolog to pretend that our caller pushed
   it.

   Normally, this macro will push all remaining incoming registers on the
   stack and set PRETEND_SIZE to the length of the registers pushed.  */

#define SETUP_INCOMING_VARARGS(CUM,MODE,TYPE,PRETEND_SIZE,NO_RTL)	\
{ if ((CUM).words < 8)							\
    {									\
      int first_reg_offset = (CUM).words;				\
									\
      if (MUST_PASS_IN_STACK (MODE, TYPE))				\
	first_reg_offset += RS6000_ARG_SIZE (TYPE_MODE (TYPE), TYPE, 1); \
									\
      if (first_reg_offset > 8)						\
	first_reg_offset = 8;						\
									\
      if (! (NO_RTL) && first_reg_offset != 8)				\
	move_block_from_reg						\
	  (3 + first_reg_offset,					\
	   gen_rtx (MEM, BLKmode,					\
		    plus_constant (virtual_incoming_args_rtx,		\
				   first_reg_offset * 4)),		\
	   8 - first_reg_offset);					\
      PRETEND_SIZE = (8 - first_reg_offset) * UNITS_PER_WORD;		\
    }									\
}

/* This macro generates the assembly code for function entry.
   FILE is a stdio stream to output the code to.
   SIZE is an int: how many units of temporary storage to allocate.
   Refer to the array `regs_ever_live' to determine which registers
   to save; `regs_ever_live[I]' is nonzero if register number I
   is ever used in the function.  This macro is responsible for
   knowing which registers should not be saved even if used.  */

#define FUNCTION_PROLOGUE(FILE, SIZE) output_prolog (FILE, SIZE)

/* Output assembler code to FILE to increment profiler label # LABELNO
   for profiling a function entry.  */

#define FUNCTION_PROFILER(FILE, LABELNO)	\
  output_function_profiler ((FILE), (LABELNO));

/* EXIT_IGNORE_STACK should be nonzero if, when returning from a function,
   the stack pointer does not matter. No definition is equivalent to
   always zero.

   On the RS/6000, this is non-zero because we can restore the stack from
   its backpointer, which we maintain.  */
#define EXIT_IGNORE_STACK	1

/* This macro generates the assembly code for function exit,
   on machines that need it.  If FUNCTION_EPILOGUE is not defined
   then individual return instructions are generated for each
   return statement.  Args are same as for FUNCTION_PROLOGUE.

   The function epilogue should not depend on the current stack pointer!
   It should use the frame pointer only.  This is mandatory because
   of alloca; we also take advantage of it to omit stack adjustments
   before returning.  */

#define FUNCTION_EPILOGUE(FILE, SIZE) output_epilog (FILE, SIZE)

/* Output assembler code for a block containing the constant parts
   of a trampoline, leaving space for the variable parts.

   The trampoline should set the static chain pointer to value placed
   into the trampoline and should branch to the specified routine.

   On the RS/6000, this is not code at all, but merely a data area,
   since that is the way all functions are called.  The first word is
   the address of the function, the second word is the TOC pointer (r2),
   and the third word is the static chain value.  */

#define TRAMPOLINE_TEMPLATE(FILE) { fprintf (FILE, "\t.long 0, 0, 0\n"); }

/* Length in units of the trampoline for entering a nested function.  */

#define TRAMPOLINE_SIZE    12

/* Emit RTL insns to initialize the variable parts of a trampoline.
   FNADDR is an RTX for the address of the function's pure code.
   CXT is an RTX for the static chain value for the function.  */

#define INITIALIZE_TRAMPOLINE(ADDR, FNADDR, CXT)		\
{								\
  emit_move_insn (gen_rtx (MEM, SImode,				\
			   memory_address (SImode, (ADDR))),	\
		  gen_rtx (MEM, SImode,				\
			   memory_address (SImode, (FNADDR))));	\
  emit_move_insn (gen_rtx (MEM, SImode,				\
			   memory_address (SImode,		\
					   plus_constant ((ADDR), 4))), \
		  gen_rtx (MEM, SImode,				\
			   memory_address (SImode,		\
					   plus_constant ((FNADDR), 4)))); \
  emit_move_insn (gen_rtx (MEM, SImode,				\
			   memory_address (SImode,		\
					   plus_constant ((ADDR), 8))), \
		  force_reg (SImode, (CXT)));			\
}

/* Definitions for register eliminations.

   We have two registers that can be eliminated on the RS/6000.  First, the
   frame pointer register can often be eliminated in favor of the stack
   pointer register.  Secondly, the argument pointer register can always be
   eliminated; it is replaced with either the stack or frame pointer.  */

/* This is an array of structures.  Each structure initializes one pair
   of eliminable registers.  The "from" register number is given first,
   followed by "to".  Eliminations of the same "from" register are listed
   in order of preference.  */
#define ELIMINABLE_REGS				\
{{ FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM},	\
 { ARG_POINTER_REGNUM, STACK_POINTER_REGNUM},	\
 { ARG_POINTER_REGNUM, FRAME_POINTER_REGNUM} }

/* Given FROM and TO register numbers, say whether this elimination is allowed.
   Frame pointer elimination is automatically handled.

   For the RS/6000, if frame pointer elimination is being done, we would like
   to convert ap into fp, not sp.  */

#define CAN_ELIMINATE(FROM, TO)					\
 ((FROM) == ARG_POINTER_REGNUM && (TO) == STACK_POINTER_REGNUM	\
  ? ! frame_pointer_needed					\
  : 1)

/* Define the offset between two registers, one to be eliminated, and the other
   its replacement, at the start of a routine.  */
#define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET)			\
{									\
  int total_stack_size = (rs6000_sa_size () + get_frame_size ()		\
			  + current_function_outgoing_args_size);	\
									\
  total_stack_size = (total_stack_size + 7) & ~7;			\
									\
 if ((FROM) == FRAME_POINTER_REGNUM && (TO) == STACK_POINTER_REGNUM)	\
    {									\
      if (rs6000_pushes_stack ())					\
	(OFFSET) = 0;							\
      else								\
	(OFFSET) = - total_stack_size;					\
    }									\
  else if ((FROM) == ARG_POINTER_REGNUM && (TO) == FRAME_POINTER_REGNUM) \
      (OFFSET) = total_stack_size;					\
  else if ((FROM) == ARG_POINTER_REGNUM && (TO) == STACK_POINTER_REGNUM) \
    {									\
      if (rs6000_pushes_stack ())					\
	(OFFSET) = total_stack_size;					\
      else								\
	(OFFSET) = 0;							\
    }									\
  else									\
    abort ();								\
}

/* Addressing modes, and classification of registers for them.  */

/* #define HAVE_POST_INCREMENT */
/* #define HAVE_POST_DECREMENT */

#define HAVE_PRE_DECREMENT
#define HAVE_PRE_INCREMENT

/* Macros to check register numbers against specific register classes.  */

/* These assume that REGNO is a hard or pseudo reg number.
   They give nonzero only if REGNO is a hard reg of the suitable class
   or a pseudo reg currently allocated to a suitable hard reg.
   Since they use reg_renumber, they are safe only once reg_renumber
   has been allocated, which happens in local-alloc.c.  */

#define REGNO_OK_FOR_INDEX_P(REGNO)				\
((REGNO) < FIRST_PSEUDO_REGISTER				\
 ? (REGNO) <= 31 || (REGNO) == 67				\
 : (reg_renumber[REGNO] >= 0					\
    && (reg_renumber[REGNO] <= 31 || reg_renumber[REGNO] == 67)))

#define REGNO_OK_FOR_BASE_P(REGNO)				\
((REGNO) < FIRST_PSEUDO_REGISTER				\
 ? ((REGNO) > 0 && (REGNO) <= 31) || (REGNO) == 67		\
 : (reg_renumber[REGNO] > 0					\
    && (reg_renumber[REGNO] <= 31 || reg_renumber[REGNO] == 67)))

/* Maximum number of registers that can appear in a valid memory address.  */

#define MAX_REGS_PER_ADDRESS 2

/* Recognize any constant value that is a valid address.  */

#define CONSTANT_ADDRESS_P(X)  CONSTANT_P (X)

/* Nonzero if the constant value X is a legitimate general operand.
   It is given that X satisfies CONSTANT_P or is a CONST_DOUBLE.

   On the RS/6000, all integer constants are acceptable, most won't be valid
   for particular insns, though.  Only easy FP constants are
   acceptable.  */

#define LEGITIMATE_CONSTANT_P(X)				\
  (GET_CODE (X) != CONST_DOUBLE || GET_MODE (X) == VOIDmode	\
   || easy_fp_constant (X, GET_MODE (X)))

/* The macros REG_OK_FOR..._P assume that the arg is a REG rtx
   and check its validity for a certain class.
   We have two alternate definitions for each of them.
   The usual definition accepts all pseudo regs; the other rejects
   them unless they have been allocated suitable hard regs.
   The symbol REG_OK_STRICT causes the latter definition to be used.

   Most source files want to accept pseudo regs in the hope that
   they will get allocated to the class that the insn wants them to be in.
   Source files for reload pass need to be strict.
   After reload, it makes no difference, since pseudo regs have
   been eliminated by then.  */

#ifndef REG_OK_STRICT

/* Nonzero if X is a hard reg that can be used as an index
   or if it is a pseudo reg.  */
#define REG_OK_FOR_INDEX_P(X)			\
  (REGNO (X) <= 31 || REGNO (X) == 67 || REGNO (X) >= FIRST_PSEUDO_REGISTER)

/* Nonzero if X is a hard reg that can be used as a base reg
   or if it is a pseudo reg.  */
#define REG_OK_FOR_BASE_P(X)					 \
  (REGNO (X) > 0 && REG_OK_FOR_INDEX_P (X))

#else

/* Nonzero if X is a hard reg that can be used as an index.  */
#define REG_OK_FOR_INDEX_P(X) REGNO_OK_FOR_INDEX_P (REGNO (X))
/* Nonzero if X is a hard reg that can be used as a base reg.  */
#define REG_OK_FOR_BASE_P(X) REGNO_OK_FOR_BASE_P (REGNO (X))

#endif

/* GO_IF_LEGITIMATE_ADDRESS recognizes an RTL expression
   that is a valid memory address for an instruction.
   The MODE argument is the machine mode for the MEM expression
   that wants to use this address.

   On the RS/6000, there are four valid address: a SYMBOL_REF that
   refers to a constant pool entry of an address (or the sum of it
   plus a constant), a short (16-bit signed) constant plus a register,
   the sum of two registers, or a register indirect, possibly with an
   auto-increment.  For DFmode and DImode with an constant plus register,
   we must ensure that both words are addressable.  */

#define LEGITIMATE_CONSTANT_POOL_BASE_P(X)				\
  (GET_CODE (X) == SYMBOL_REF && CONSTANT_POOL_ADDRESS_P (X)		\
   && ASM_OUTPUT_SPECIAL_POOL_ENTRY_P (get_pool_constant (X)))

#define LEGITIMATE_CONSTANT_POOL_ADDRESS_P(X)				\
  (LEGITIMATE_CONSTANT_POOL_BASE_P (X)					\
   || (GET_CODE (X) == CONST && GET_CODE (XEXP (X, 0)) == PLUS		\
       && GET_CODE (XEXP (XEXP (X, 0), 1)) == CONST_INT			\
       && LEGITIMATE_CONSTANT_POOL_BASE_P (XEXP (XEXP (X, 0), 0))))

#define LEGITIMATE_ADDRESS_INTEGER_P(X,OFFSET)				\
 (GET_CODE (X) == CONST_INT						\
  && (unsigned) (INTVAL (X) + (OFFSET) + 0x8000) < 0x10000)

#define LEGITIMATE_OFFSET_ADDRESS_P(MODE,X)		\
 (GET_CODE (X) == PLUS					\
  && GET_CODE (XEXP (X, 0)) == REG			\
  && REG_OK_FOR_BASE_P (XEXP (X, 0))			\
  && LEGITIMATE_ADDRESS_INTEGER_P (XEXP (X, 1), 0)	\
  && (((MODE) != DFmode && (MODE) != DImode)		\
      || LEGITIMATE_ADDRESS_INTEGER_P (XEXP (X, 1), 4)))

#define LEGITIMATE_INDEXED_ADDRESS_P(X)		\
 (GET_CODE (X) == PLUS				\
  && GET_CODE (XEXP (X, 0)) == REG		\
  && GET_CODE (XEXP (X, 1)) == REG		\
  && ((REG_OK_FOR_BASE_P (XEXP (X, 0))		\
       && REG_OK_FOR_INDEX_P (XEXP (X, 1)))	\
      || (REG_OK_FOR_BASE_P (XEXP (X, 1))	\
	  && REG_OK_FOR_INDEX_P (XEXP (X, 0)))))

#define LEGITIMATE_INDIRECT_ADDRESS_P(X)	\
  (GET_CODE (X) == REG && REG_OK_FOR_BASE_P (X))

#define GO_IF_LEGITIMATE_ADDRESS(MODE, X, ADDR)		\
{ if (LEGITIMATE_INDIRECT_ADDRESS_P (X))		\
    goto ADDR;						\
  if (GET_CODE (X) == PRE_INC				\
      && LEGITIMATE_INDIRECT_ADDRESS_P (XEXP (X, 0)))	\
    goto ADDR;						\
  if (GET_CODE (X) == PRE_DEC				\
      && LEGITIMATE_INDIRECT_ADDRESS_P (XEXP (X, 0)))	\
    goto ADDR;						\
  if (LEGITIMATE_CONSTANT_POOL_ADDRESS_P (X))		\
    goto ADDR;						\
  if (LEGITIMATE_OFFSET_ADDRESS_P (MODE, X))		\
    goto ADDR;						\