rs6000.c

gcc-2.95.3 Linux下最常用的C编译器

/* Return 1 if the operand is a non-special register or a 32-bit constant
   that can be used as the operand of an OR or XOR insn on the RS/6000.  */

int
logical_u_operand (op, mode)
     register rtx op;
     enum machine_mode mode;
{
  return (gpc_reg_operand (op, mode)
	  || (GET_CODE (op) == CONST_INT
	      && INTVAL (op) > 0
#if HOST_BITS_PER_WIDE_INT != 32
	      && INTVAL (op) < ((HOST_WIDE_INT) 1 << 32)
#endif
	      && ((INTVAL (op) & GET_MODE_MASK (mode)
		   & (~ (HOST_WIDE_INT) 0xffff)) == 0
		  || (INTVAL (op) & GET_MODE_MASK (mode)
		      & (~ (unsigned HOST_WIDE_INT) 0xffff0000u)) == 0))
#if HOST_BITS_PER_WIDE_INT == 32
	  || (GET_CODE (op) == CONST_DOUBLE
	      && CONST_DOUBLE_HIGH (op) == 0
	      && ((CONST_DOUBLE_LOW (op)
		   & (~ (unsigned HOST_WIDE_INT) 0xffff0000u)) == 0))
#endif
      );
}

/* Return 1 if C is a constant that is not a logical operand (as
   above).  */

int
non_logical_cint_operand (op, mode)
     register rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return (GET_CODE (op) == CONST_INT
#if HOST_BITS_PER_WIDE_INT != 32
	  && INTVAL (op) < ((HOST_WIDE_INT) 1 << 32)
#endif
	  && (INTVAL (op) & GET_MODE_MASK (mode) &
	      (~ (HOST_WIDE_INT) 0xffff)) != 0
	  && (INTVAL (op) & GET_MODE_MASK (mode) &
	      (~ (unsigned HOST_WIDE_INT) 0xffff0000u)) != 0);
}

/* Return 1 if C is an unsigned 32-bit constant that is not a
   logical operand (as above).  */

int
non_logical_u_cint_operand (op, mode)
     register rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return ((GET_CODE (op) == CONST_INT
	   && INTVAL (op) > 0
#if HOST_BITS_PER_WIDE_INT != 32
	   && INTVAL (op) < ((HOST_WIDE_INT) 1 << 32)
#endif
	   && (INTVAL (op) & GET_MODE_MASK (mode)
	       & (~ (HOST_WIDE_INT) 0xffff)) != 0
	   && (INTVAL (op) & GET_MODE_MASK (mode)
	       & (~ (unsigned HOST_WIDE_INT) 0xffff0000u)) != 0)
#if HOST_BITS_PER_WIDE_INT == 32
	  || (GET_CODE (op) == CONST_DOUBLE
	      && CONST_DOUBLE_HIGH (op) == 0
	      && (CONST_DOUBLE_LOW (op) & (~ (HOST_WIDE_INT) 0xffff)) != 0
	      && (CONST_DOUBLE_LOW (op)
		  & (~ (unsigned HOST_WIDE_INT) 0xffff0000u)) != 0));
#endif
}

/* Return 1 if C is a constant that can be encoded in a 32-bit mask on the
   RS/6000.  It is if there are no more than two 1->0 or 0->1 transitions.
   Reject all ones and all zeros, since these should have been optimized
   away and confuse the making of MB and ME.  */

int
mask_operand (op, mode)
     register rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  HOST_WIDE_INT c;
  int i;
  int last_bit_value;
  int transitions = 0;

  if (GET_CODE (op) != CONST_INT)
    return 0;

  c = INTVAL (op);

  if (c == 0 || c == ~0)
    return 0;

  last_bit_value = c & 1;

  for (i = 1; i < 32; i++)
    if (((c >>= 1) & 1) != last_bit_value)
      last_bit_value ^= 1, transitions++;

  return transitions <= 2;
}

/* Return 1 if the operand is a constant that is a PowerPC64 mask.
   It is if there are no more than one 1->0 or 0->1 transitions.
   Reject all ones and all zeros, since these should have been optimized
   away and confuse the making of MB and ME.  */

int
mask64_operand (op, mode)
     register rtx op;
     enum machine_mode mode;
{
  if (GET_CODE (op) == CONST_INT)
    {
      HOST_WIDE_INT c = INTVAL (op);
      int i;
      int last_bit_value;
      int transitions = 0;

      if (c == 0 || c == ~0)
	return 0;

      last_bit_value = c & 1;

      for (i = 1; i < HOST_BITS_PER_WIDE_INT; i++)
	if (((c >>= 1) & 1) != last_bit_value)
	  last_bit_value ^= 1, transitions++;

#if HOST_BITS_PER_WIDE_INT == 32
      /* Consider CONST_INT sign-extended.  */
      transitions += (last_bit_value != 1);
#endif

      return transitions <= 1;
    }
  else if (GET_CODE (op) == CONST_DOUBLE
	   && (mode == VOIDmode || mode == DImode))
    {
      HOST_WIDE_INT low = CONST_DOUBLE_LOW (op);
#if HOST_BITS_PER_WIDE_INT == 32
      HOST_WIDE_INT high = CONST_DOUBLE_HIGH (op);
#endif
      int i;
      int last_bit_value;
      int transitions = 0;

      if ((low == 0
#if HOST_BITS_PER_WIDE_INT == 32
	  && high == 0
#endif
	   )
	  || (low == ~0
#if HOST_BITS_PER_WIDE_INT == 32
	      && high == ~0
#endif
	      ))
	return 0;

      last_bit_value = low & 1;

      for (i = 1; i < HOST_BITS_PER_WIDE_INT; i++)
	if (((low >>= 1) & 1) != last_bit_value)
	  last_bit_value ^= 1, transitions++;

#if HOST_BITS_PER_WIDE_INT == 32
      if ((high & 1) != last_bit_value)
	last_bit_value ^= 1, transitions++;

      for (i = 1; i < HOST_BITS_PER_WIDE_INT; i++)
	if (((high >>= 1) & 1) != last_bit_value)
	  last_bit_value ^= 1, transitions++;
#endif

      return transitions <= 1;
    }
  else
    return 0;
}

/* Return 1 if the operand is either a non-special register or a constant
   that can be used as the operand of a PowerPC64 logical AND insn.  */

int
and64_operand (op, mode)
    register rtx op;
    enum machine_mode mode;
{
  if (fixed_regs[68])	/* CR0 not available, don't do andi./andis. */
    return (gpc_reg_operand (op, mode) || mask64_operand (op, mode));

  return (logical_operand (op, mode) || mask64_operand (op, mode));
}

/* Return 1 if the operand is either a non-special register or a
   constant that can be used as the operand of an RS/6000 logical AND insn.  */

int
and_operand (op, mode)
    register rtx op;
    enum machine_mode mode;
{
  if (fixed_regs[68])	/* CR0 not available, don't do andi./andis. */
    return (gpc_reg_operand (op, mode) || mask_operand (op, mode));

  return (logical_operand (op, mode) || mask_operand (op, mode));
}

/* Return 1 if the operand is a general register or memory operand.  */

int
reg_or_mem_operand (op, mode)
     register rtx op;
     register enum machine_mode mode;
{
  return (gpc_reg_operand (op, mode)
	  || memory_operand (op, mode)
	  || volatile_mem_operand (op, mode));
}

/* Return 1 if the operand is a general register or memory operand without
   pre-inc or pre_dec which produces invalid form of PowerPC lwa
   instruction.  */

int
lwa_operand (op, mode)
     register rtx op;
     register enum machine_mode mode;
{
  rtx inner = op;

  if (reload_completed && GET_CODE (inner) == SUBREG)
    inner = SUBREG_REG (inner);
    
  return gpc_reg_operand (inner, mode)
    || (memory_operand (inner, mode)
	&& GET_CODE (XEXP (inner, 0)) != PRE_INC
	&& GET_CODE (XEXP (inner, 0)) != PRE_DEC);
}

/* Return 1 if the operand, used inside a MEM, is a valid first argument
   to CALL.  This is a SYMBOL_REF or a pseudo-register, which will be
   forced to lr.  */

int
call_operand (op, mode)
     register rtx op;
     enum machine_mode mode;
{
  if (mode != VOIDmode && GET_MODE (op) != mode)
    return 0;

  return (GET_CODE (op) == SYMBOL_REF
	  || (GET_CODE (op) == REG && REGNO (op) >= FIRST_PSEUDO_REGISTER));
}


/* Return 1 if the operand is a SYMBOL_REF for a function known to be in
   this file and the function is not weakly defined. */

int
current_file_function_operand (op, mode)
     register rtx op;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
  return (GET_CODE (op) == SYMBOL_REF
	  && (SYMBOL_REF_FLAG (op)
	      || (op == XEXP (DECL_RTL (current_function_decl), 0)
	          && !DECL_WEAK (current_function_decl))));
}


/* Return 1 if this operand is a valid input for a move insn.  */

int
input_operand (op, mode)
     register rtx op;
     enum machine_mode mode;
{
  /* Memory is always valid.  */
  if (memory_operand (op, mode))
    return 1;

  /* Only a tiny bit of handling for CONSTANT_P_RTX is necessary.  */
  if (GET_CODE (op) == CONSTANT_P_RTX)
    return 1;

  /* For floating-point, easy constants are valid.  */
  if (GET_MODE_CLASS (mode) == MODE_FLOAT
      && CONSTANT_P (op)
      && easy_fp_constant (op, mode))
    return 1;

  /* Allow any integer constant.  */
  if (GET_MODE_CLASS (mode) == MODE_INT
      && (GET_CODE (op) == CONST_INT
	  || GET_CODE (op) == CONST_DOUBLE))
    return 1;

  /* For floating-point or multi-word mode, the only remaining valid type
     is a register.  */
  if (GET_MODE_CLASS (mode) == MODE_FLOAT
      || GET_MODE_SIZE (mode) > UNITS_PER_WORD)
    return register_operand (op, mode);

  /* The only cases left are integral modes one word or smaller (we
     do not get called for MODE_CC values).  These can be in any
     register.  */
  if (register_operand (op, mode))
    return 1;

  /* A SYMBOL_REF referring to the TOC is valid.  */
  if (LEGITIMATE_CONSTANT_POOL_ADDRESS_P (op))
    return 1;

  /* Windows NT allows SYMBOL_REFs and LABEL_REFs against the TOC
     directly in the instruction stream */
  if (DEFAULT_ABI == ABI_NT
      && (GET_CODE (op) == SYMBOL_REF || GET_CODE (op) == LABEL_REF))
    return 1;

  /* V.4 allows SYMBOL_REFs and CONSTs that are in the small data region
     to be valid.  */
  if ((DEFAULT_ABI == ABI_V4 || DEFAULT_ABI == ABI_SOLARIS)
      && (GET_CODE (op) == SYMBOL_REF || GET_CODE (op) == CONST)
      && small_data_operand (op, Pmode))
    return 1;

  return 0;
}

/* Return 1 for an operand in small memory on V.4/eabi */

int
small_data_operand (op, mode)
     rtx op ATTRIBUTE_UNUSED;
     enum machine_mode mode ATTRIBUTE_UNUSED;
{
#if TARGET_ELF
  rtx sym_ref, const_part;

  if (rs6000_sdata == SDATA_NONE || rs6000_sdata == SDATA_DATA)
    return 0;

  if (DEFAULT_ABI != ABI_V4 && DEFAULT_ABI != ABI_SOLARIS)
    return 0;

  if (GET_CODE (op) == SYMBOL_REF)
    sym_ref = op;

  else if (GET_CODE (op) != CONST
	   || GET_CODE (XEXP (op, 0)) != PLUS
	   || GET_CODE (XEXP (XEXP (op, 0), 0)) != SYMBOL_REF
	   || GET_CODE (XEXP (XEXP (op, 0), 1)) != CONST_INT)
    return 0;

  else
    {
      rtx sum = XEXP (op, 0);
      HOST_WIDE_INT summand;

      /* We have to be careful here, because it is the referenced address
        that must be 32k from _SDA_BASE_, not just the symbol.  */
      summand = INTVAL (XEXP (sum, 1));
      if (summand < 0 || summand > g_switch_value)
       return 0;

      sym_ref = XEXP (sum, 0);
    }

  if (*XSTR (sym_ref, 0) != '@')
    return 0;

  return 1;

#else
  return 0;
#endif
}


/* Initialize a variable CUM of type CUMULATIVE_ARGS
   for a call to a function whose data type is FNTYPE.
   For a library call, FNTYPE is 0.

   For incoming args we set the number of arguments in the prototype large
   so we never return a PARALLEL.  */

void
init_cumulative_args (cum, fntype, libname, incoming)
     CUMULATIVE_ARGS *cum;
     tree fntype;
     rtx libname ATTRIBUTE_UNUSED;
     int incoming;
{
  static CUMULATIVE_ARGS zero_cumulative;
  enum rs6000_abi abi = DEFAULT_ABI;

  *cum = zero_cumulative;
  cum->words = 0;
  cum->fregno = FP_ARG_MIN_REG;
  cum->prototype = (fntype && TYPE_ARG_TYPES (fntype));
  cum->call_cookie = CALL_NORMAL;
  cum->sysv_gregno = GP_ARG_MIN_REG;

  if (incoming)
    cum->nargs_prototype = 1000;		/* don't return a PARALLEL */

  else if (cum->prototype)
    cum->nargs_prototype = (list_length (TYPE_ARG_TYPES (fntype)) - 1
			    + (TYPE_MODE (TREE_TYPE (fntype)) == BLKmode
			       || RETURN_IN_MEMORY (TREE_TYPE (fntype))));

  else
    cum->nargs_prototype = 0;

  cum->orig_nargs = cum->nargs_prototype;

  /* Check for DLL import functions */
  if (abi == ABI_NT
      && fntype
      && lookup_attribute ("dllimport", TYPE_ATTRIBUTES (fntype)))
    cum->call_cookie = CALL_NT_DLLIMPORT;

  /* Also check for longcall's */
  else if (fntype && lookup_attribute ("longcall", TYPE_ATTRIBUTES (fntype)))
    cum->call_cookie = CALL_LONG;

  if (TARGET_DEBUG_ARG)
    {
      fprintf (stderr, "\ninit_cumulative_args:");
      if (fntype)
	{
	  tree ret_type = TREE_TYPE (fntype);
	  fprintf (stderr, " ret code = %s,",
		   tree_code_name[ (int)TREE_CODE (ret_type) ]);
	}

      if (cum->call_cookie & CALL_NT_DLLIMPORT)
	fprintf (stderr, " dllimport,");

      if (cum->call_cookie & CALL_LONG)
	fprintf (stderr, " longcall,");

      fprintf (stderr, " proto = %d, nargs = %d\n",
	       cum->prototype, cum->nargs_prototype);
    }
}

/* If defined, a C expression which determines whether, and in which
   direction, to pad out an argument with extra space.  The value
   should be of type `enum direction': either `upward' to pad above
   the argument, `downward' to pad below, or `none' to inhibit
   padding.

   For the AIX ABI structs are always stored left shifted in their
   argument slot.  */

int
function_arg_padding (mode, type)
     enum machine_mode mode;
     tree type;
{
  if (type != 0 && AGGREGATE_TYPE_P (type))
    return (int)upward;

  /* This is the default definition.  */
  return (! BYTES_BIG_ENDIAN