m68hc11.c

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      rtx op = XEXP (operand, 0);

      if (symbolic_memory_operand (op, mode))
	return 1;
    }
  return 0;
}

int
m68hc11_indirect_p (rtx operand, enum machine_mode mode)
{
  if (GET_CODE (operand) == MEM && GET_MODE (operand) == mode)
    {
      rtx op = XEXP (operand, 0);
      int addr_mode;

      if (m68hc11_page0_symbol_p (op))
        return 1;

      if (symbolic_memory_operand (op, mode))
	return TARGET_M6812;

      if (reload_in_progress)
        return 1;

      operand = XEXP (operand, 0);
      addr_mode = m68hc11_addr_mode | (reload_completed ? ADDR_STRICT : 0);
      return m68hc11_valid_addressing_p (operand, mode, addr_mode);
    }
  return 0;
}

int
memory_indexed_operand (rtx operand, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  if (GET_CODE (operand) != MEM)
    return 0;

  operand = XEXP (operand, 0);
  if (GET_CODE (operand) == PLUS)
    {
      if (GET_CODE (XEXP (operand, 0)) == REG)
	operand = XEXP (operand, 0);
      else if (GET_CODE (XEXP (operand, 1)) == REG)
	operand = XEXP (operand, 1);
    }
  return GET_CODE (operand) == REG
    && (REGNO (operand) >= FIRST_PSEUDO_REGISTER
	|| A_REGNO_P (REGNO (operand)));
}

int
push_pop_operand_p (rtx operand)
{
  if (GET_CODE (operand) != MEM)
    {
      return 0;
    }
  operand = XEXP (operand, 0);
  return PUSH_POP_ADDRESS_P (operand);
}

/* Returns 1 if OP is either a symbol reference or a sum of a symbol
   reference and a constant.  */

int
symbolic_memory_operand (rtx op, enum machine_mode mode)
{
  switch (GET_CODE (op))
    {
    case SYMBOL_REF:
    case LABEL_REF:
      return 1;

    case CONST:
      op = XEXP (op, 0);
      return ((GET_CODE (XEXP (op, 0)) == SYMBOL_REF
	       || GET_CODE (XEXP (op, 0)) == LABEL_REF)
	      && GET_CODE (XEXP (op, 1)) == CONST_INT);

      /* ??? This clause seems to be irrelevant.  */
    case CONST_DOUBLE:
      return GET_MODE (op) == mode;

    case PLUS:
      return symbolic_memory_operand (XEXP (op, 0), mode)
	&& symbolic_memory_operand (XEXP (op, 1), mode);

    default:
      return 0;
    }
}

/* Emit the code to build the trampoline used to call a nested function.
   
   68HC11               68HC12

   ldy #&CXT            movw #&CXT,*_.d1
   sty *_.d1            jmp FNADDR
   jmp FNADDR

*/
void
m68hc11_initialize_trampoline (rtx tramp, rtx fnaddr, rtx cxt)
{
  const char *static_chain_reg = reg_names[STATIC_CHAIN_REGNUM];

  /* Skip the '*'.  */
  if (*static_chain_reg == '*')
    static_chain_reg++;
  if (TARGET_M6811)
    {
      emit_move_insn (gen_rtx_MEM (HImode, tramp), GEN_INT (0x18ce));
      emit_move_insn (gen_rtx_MEM (HImode, plus_constant (tramp, 2)), cxt);
      emit_move_insn (gen_rtx_MEM (HImode, plus_constant (tramp, 4)),
                      GEN_INT (0x18df));
      emit_move_insn (gen_rtx_MEM (QImode, plus_constant (tramp, 6)),
                      gen_rtx_CONST (QImode,
                                     gen_rtx_SYMBOL_REF (Pmode,
                                                         static_chain_reg)));
      emit_move_insn (gen_rtx_MEM (QImode, plus_constant (tramp, 7)),
                      GEN_INT (0x7e));
      emit_move_insn (gen_rtx_MEM (HImode, plus_constant (tramp, 8)), fnaddr);
    }
  else
    {
      emit_move_insn (gen_rtx_MEM (HImode, tramp), GEN_INT (0x1803));
      emit_move_insn (gen_rtx_MEM (HImode, plus_constant (tramp, 2)), cxt);
      emit_move_insn (gen_rtx_MEM (HImode, plus_constant (tramp, 4)),
                      gen_rtx_CONST (HImode,
                                     gen_rtx_SYMBOL_REF (Pmode,
                                                         static_chain_reg)));
      emit_move_insn (gen_rtx_MEM (QImode, plus_constant (tramp, 6)),
                      GEN_INT (0x06));
      emit_move_insn (gen_rtx_MEM (HImode, plus_constant (tramp, 7)), fnaddr);
    }
}

/* Declaration of types.  */

/* Handle an "tiny_data" attribute; arguments as in
   struct attribute_spec.handler.  */
static tree
m68hc11_handle_page0_attribute (tree *node, tree name,
                                tree args ATTRIBUTE_UNUSED,
                                int flags ATTRIBUTE_UNUSED, bool *no_add_attrs)
{
  tree decl = *node;

  if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
    {
      DECL_SECTION_NAME (decl) = build_string (6, ".page0");
    }
  else
    {
      warning (OPT_Wattributes, "%qs attribute ignored",
	       IDENTIFIER_POINTER (name));
      *no_add_attrs = true;
    }

  return NULL_TREE;
}

const struct attribute_spec m68hc11_attribute_table[] =
{
  /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
  { "interrupt", 0, 0, false, true,  true,  m68hc11_handle_fntype_attribute },
  { "trap",      0, 0, false, true,  true,  m68hc11_handle_fntype_attribute },
  { "far",       0, 0, false, true,  true,  m68hc11_handle_fntype_attribute },
  { "near",      0, 0, false, true,  true,  m68hc11_handle_fntype_attribute },
  { "page0",     0, 0, false, false, false, m68hc11_handle_page0_attribute },
  { NULL,        0, 0, false, false, false, NULL }
};

/* Keep track of the symbol which has a `trap' attribute and which uses
   the `swi' calling convention.  Since there is only one trap, we only
   record one such symbol.  If there are several, a warning is reported.  */
static rtx trap_handler_symbol = 0;

/* Handle an attribute requiring a FUNCTION_TYPE, FIELD_DECL or TYPE_DECL;
   arguments as in struct attribute_spec.handler.  */
static tree
m68hc11_handle_fntype_attribute (tree *node, tree name,
                                 tree args ATTRIBUTE_UNUSED,
                                 int flags ATTRIBUTE_UNUSED,
                                 bool *no_add_attrs)
{
  if (TREE_CODE (*node) != FUNCTION_TYPE
      && TREE_CODE (*node) != METHOD_TYPE
      && TREE_CODE (*node) != FIELD_DECL
      && TREE_CODE (*node) != TYPE_DECL)
    {
      warning (OPT_Wattributes, "%qs attribute only applies to functions",
	       IDENTIFIER_POINTER (name));
      *no_add_attrs = true;
    }

  return NULL_TREE;
}
/* Undo the effects of the above.  */

static const char *
m68hc11_strip_name_encoding (const char *str)
{
  return str + (*str == '*' || *str == '@' || *str == '&');
}

static void
m68hc11_encode_label (tree decl)
{
  const char *str = XSTR (XEXP (DECL_RTL (decl), 0), 0);
  int len = strlen (str);
  char *newstr = alloca (len + 2);

  newstr[0] = '@';
  strcpy (&newstr[1], str);

  XSTR (XEXP (DECL_RTL (decl), 0), 0) = ggc_alloc_string (newstr, len + 1);
}

/* Return 1 if this is a symbol in page0  */
int
m68hc11_page0_symbol_p (rtx x)
{
  switch (GET_CODE (x))
    {
    case SYMBOL_REF:
      return XSTR (x, 0) != 0 && XSTR (x, 0)[0] == '@';

    case CONST:
      return m68hc11_page0_symbol_p (XEXP (x, 0));

    case PLUS:
      if (!m68hc11_page0_symbol_p (XEXP (x, 0)))
        return 0;

      return GET_CODE (XEXP (x, 1)) == CONST_INT
        && INTVAL (XEXP (x, 1)) < 256
        && INTVAL (XEXP (x, 1)) >= 0;

    default:
      return 0;
    }
}

/* We want to recognize trap handlers so that we handle calls to traps
   in a special manner (by issuing the trap).  This information is stored
   in SYMBOL_REF_FLAG.  */

static void
m68hc11_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
{
  tree func_attr;
  int trap_handler;
  int is_far = 0;
  
  if (TREE_CODE (decl) == VAR_DECL)
    {
      if (lookup_attribute ("page0", DECL_ATTRIBUTES (decl)) != 0)
        m68hc11_encode_label (decl);
      return;
    }

  if (TREE_CODE (decl) != FUNCTION_DECL)
    return;

  func_attr = TYPE_ATTRIBUTES (TREE_TYPE (decl));


  if (lookup_attribute ("far", func_attr) != NULL_TREE)
    is_far = 1;
  else if (lookup_attribute ("near", func_attr) == NULL_TREE)
    is_far = TARGET_LONG_CALLS != 0;

  trap_handler = lookup_attribute ("trap", func_attr) != NULL_TREE;
  if (trap_handler && is_far)
    {
      warning (OPT_Wattributes, "%<trap%> and %<far%> attributes are "
	       "not compatible, ignoring %<far%>");
      trap_handler = 0;
    }
  if (trap_handler)
    {
      if (trap_handler_symbol != 0)
        warning (OPT_Wattributes, "%<trap%> attribute is already used");
      else
        trap_handler_symbol = XEXP (rtl, 0);
    }
  SYMBOL_REF_FLAG (XEXP (rtl, 0)) = is_far;
}

static unsigned int
m68hc11_section_type_flags (tree decl, const char *name, int reloc)
{
  unsigned int flags = default_section_type_flags (decl, name, reloc);

  if (strncmp (name, ".eeprom", 7) == 0)
    {
      flags |= SECTION_WRITE | SECTION_CODE | SECTION_OVERRIDE;
    }

  return flags;
}

int
m68hc11_is_far_symbol (rtx sym)
{
  if (GET_CODE (sym) == MEM)
    sym = XEXP (sym, 0);

  return SYMBOL_REF_FLAG (sym);
}

int
m68hc11_is_trap_symbol (rtx sym)
{
  if (GET_CODE (sym) == MEM)
    sym = XEXP (sym, 0);

  return trap_handler_symbol != 0 && rtx_equal_p (trap_handler_symbol, sym);
}


/* Argument support functions.  */

/* Define the offset between two registers, one to be eliminated, and the
   other its replacement, at the start of a routine.  */
int
m68hc11_initial_elimination_offset (int from, int to)
{
  int trap_handler;
  tree func_attr;
  int size;
  int regno;

  /* For a trap handler, we must take into account the registers which
     are pushed on the stack during the trap (except the PC).  */
  func_attr = TYPE_ATTRIBUTES (TREE_TYPE (current_function_decl));
  current_function_interrupt = lookup_attribute ("interrupt",
						 func_attr) != NULL_TREE;
  trap_handler = lookup_attribute ("trap", func_attr) != NULL_TREE;

  if (lookup_attribute ("far", func_attr) != 0)
    current_function_far = 1;
  else if (lookup_attribute ("near", func_attr) != 0)
    current_function_far = 0;
  else
    current_function_far = (TARGET_LONG_CALLS != 0
                            && !current_function_interrupt
                            && !trap_handler);

  if (trap_handler && from == ARG_POINTER_REGNUM)
    size = 7;

  /* For a function using 'call/rtc' we must take into account the
     page register which is pushed in the call.  */
  else if (current_function_far && from == ARG_POINTER_REGNUM)
    size = 1;
  else
    size = 0;

  if (from == ARG_POINTER_REGNUM && to == HARD_FRAME_POINTER_REGNUM)
    {
      /* 2 is for the saved frame.
         1 is for the 'sts' correction when creating the frame.  */
      return get_frame_size () + 2 + m68hc11_sp_correction + size;
    }

  if (from == FRAME_POINTER_REGNUM && to == HARD_FRAME_POINTER_REGNUM)
    {
      return m68hc11_sp_correction;
    }

  /* Push any 2 byte pseudo hard registers that we need to save.  */
  for (regno = SOFT_REG_FIRST; regno < SOFT_REG_LAST; regno++)
    {
      if (regs_ever_live[regno] && !call_used_regs[regno])
	{
	  size += 2;
	}
    }

  if (from == ARG_POINTER_REGNUM && to == HARD_SP_REGNUM)
    {
      return get_frame_size () + size;
    }

  if (from == FRAME_POINTER_REGNUM && to == HARD_SP_REGNUM)
    {
      return size;
    }
  return 0;
}

/* 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.  */

void
m68hc11_init_cumulative_args (CUMULATIVE_ARGS *cum, tree fntype, rtx libname)
{
  tree ret_type;

  z_replacement_completed = 0;
  cum->words = 0;
  cum->nregs = 0;

  /* For a library call, we must find out the type of the return value.
     When the return value is bigger than 4 bytes, it is returned in
     memory.  In that case, the first argument of the library call is a
     pointer to the memory location.  Because the first argument is passed in
     register D, we have to identify this, so that the first function
     parameter is not passed in D either.  */
  if (fntype == 0)
    {
      const char *name;
      size_t len;

      if (libname == 0 || GET_CODE (libname) != SYMBOL_REF)
	return;

      /* If the library ends in 'di' or in 'df', we assume it's
         returning some DImode or some DFmode which are 64-bit wide.  */
      name = XSTR (libname, 0);
      len = strlen (name);
      if (len > 3
	  && ((name[len - 2] == 'd'
	       && (name[len - 1] == 'f' || name[len - 1] == 'i'))
	      || (name[len - 3] == 'd'
		  && (name[len - 2] == 'i' || name[len - 2] == 'f'))))
	{
	  /* We are in.  Mark the first parameter register as already used.  */
	  cum->words = 1;
	  cum->nregs = 1;
	}
      return;
    }

  ret_type = TREE_TYPE (fntype);

  if (ret_type && aggregate_value_p (ret_type, fntype))
    {
      cum->words = 1;
      cum->nregs = 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.)  */

void
m68hc11_function_arg_advance (CUMULATIVE_ARGS *cum, enum machine_mode mode,
                              tree type, int named ATTRIBUTE_UNUSED)
{
  if (mode != BLKmode)
    {
      if (cum->words == 0 && GET_MODE_SIZE (mode) == 4)
	{
	  cum->nregs = 2;
	  cum->words = GET_MODE_SIZE (mode);
	}
      else
	{
	  cum->words += GET_MODE_SIZE (mode);
	  if (cum->words <= HARD_REG_SIZE)
	    cum->nregs = 1;
	}
    }
  else
    {
      cum->words += int_size_in_bytes (type);
    }
  return;
}

/* Define where to put the arguments 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.